1 - Science of Synthesis: Knowledge Updates 2011/2 [Seite 1]
1.1 - Title page [Seite 5]
1.2 - Imprint [Seite 7]
1.3 - Preface [Seite 8]
1.4 - Abstracts [Seite 10]
1.5 - Overview [Seite 14]
1.6 - Table of Contents [Seite 16]
1.7 - Volume 3: Compounds of Groups 12 and 11 (Zn, Cd, Hg, Cu, Ag, Au) [Seite 32]
1.7.1 - 3.6 Product Class 6: Organometallic Complexes of Gold [Seite 32]
1.7.1.1 - 3.6.11 Organometallic Complexes of Gold (Update 1) [Seite 32]
1.7.1.1.1 - 3.6.11.1 Gold-Catalyzed Cycloisomerizations of Enynes [Seite 32]
1.7.1.1.1.1 - 3.6.11.1.1 Method 1: Cycloisomerization of 1,6-Enynes [Seite 34]
1.7.1.1.1.1.1 - 3.6.11.1.1.1 Variation 1: Formation of 1,3-Dienes [Seite 34]
1.7.1.1.1.1.2 - 3.6.11.1.1.2 Variation 2: Formation of Cyclobutenes or Cyclobutanones [Seite 39]
1.7.1.1.1.1.3 - 3.6.11.1.1.3 Variation 3: Formation of Cyclopropyl Rings [Seite 41]
1.7.1.1.1.1.4 - 3.6.11.1.1.4 Variation 4: Formation of Fused Rings by Cycloisomerization of Substituted 1,6-Enynes by Friedel-Crafts-Type Processes [Seite 43]
1.7.1.1.1.2 - 3.6.11.1.2 Method 2: Cycloisomerization of Dienynes [Seite 46]
1.7.1.1.1.3 - 3.6.11.1.3 Method 3: Cycloisomerization of Oxo-1,6-enynes [Seite 49]
1.7.1.1.1.3.1 - 3.6.11.1.3.1 Variation 1: Applications of the Cycloisomerization of Oxo-1,6-enynes in Total Synthesis [Seite 53]
1.7.1.1.1.4 - 3.6.11.1.4 Method 4: Inter- and Intramolecular Addition of Nucleophiles to 1,6-Enynes [Seite 55]
1.7.1.1.1.5 - 3.6.11.1.5 Method 5: Cycloisomerization of 1,5-Enynes [Seite 64]
1.7.1.1.1.6 - 3.6.11.1.6 Method 6: Inter- and Intramolecular Addition of Nucleophiles to 1,5-Enynes [Seite 76]
1.7.1.1.1.7 - 3.6.11.1.7 Method 7: Cycloisomerization of 1,n-Enynes via Migration of Propargyl Groups [Seite 80]
1.7.1.1.1.8 - 3.6.11.1.8 Method 8: Cycloisomerization of 1,7- and Higher Enynes [Seite 90]
1.7.1.2 - 3.6.12 Organometallic Complexes of Gold (Update 2) [Seite 102]
1.7.1.2.1 - 3.6.12.1 Gold-Catalyzed Propargylic Rearrangements [Seite 102]
1.7.1.2.1.1 - 3.6.12.1.1 Synthetic Method Development Based on Gold-Catalyzed 3,3-Rearrangements of Propargylic Carboxylates [Seite 102]
1.7.1.2.1.1.1 - 3.6.12.1.1.1 Reactions via Gold-Containing Oxocarbenium Intermediates [Seite 106]
1.7.1.2.1.1.1.1 - 3.6.12.1.1.1.1 Method 1: Reactions Using Indole-3-acetyl as the Acyl Group [Seite 107]
1.7.1.2.1.1.1.2 - 3.6.12.1.1.1.2 Method 2: Reactions of Substrates with Functionality at the Alkyne Terminus of the Propargylic Group [Seite 109]
1.7.1.2.1.1.1.2.1 - 3.6.12.1.1.1.2.1 Variation 1: Using Enyne Substrates [Seite 110]
1.7.1.2.1.1.1.2.2 - 3.6.12.1.1.1.2.2 Variation 2: Using 4-(Trimethylsilyl)but-2-ynyl Substrates [Seite 112]
1.7.1.2.1.1.1.3 - 3.6.12.1.1.1.3 Method 3: Reactions of 1-Arylpropargylic Carboxylates [Seite 112]
1.7.1.2.1.1.1.4 - 3.6.12.1.1.1.4 Method 4: Reactions with Hydrolytic Treatment [Seite 113]
1.7.1.2.1.1.1.4.1 - 3.6.12.1.1.1.4.1 Variation 1: Formation of a-Unsubstituted Enones [Seite 113]
1.7.1.2.1.1.1.4.2 - 3.6.12.1.1.1.4.2 Variation 2: Formation of a-Iodo- or a-Bromoenones [Seite 114]
1.7.1.2.1.1.1.5 - 3.6.12.1.1.1.5 Method 5: Intramolecular Acyl Migration [Seite 115]
1.7.1.2.1.1.1.6 - 3.6.12.1.1.1.6 Method 6: Reactions Incorporating Gold(I)/Gold(III) Catalysis [Seite 117]
1.7.1.2.1.1.1.6.1 - 3.6.12.1.1.1.6.1 Variation 1: Gold-Catalyzed Oxidative Homocoupling [Seite 117]
1.7.1.2.1.1.1.6.2 - 3.6.12.1.1.1.6.2 Variation 2: Gold-Catalyzed Oxidative Cross-Coupling Reaction [Seite 118]
1.7.1.2.1.1.1.6.3 - 3.6.12.1.1.1.6.3 Variation 3: Gold-Catalyzed Oxidative C--O Bond Formation [Seite 119]
1.7.1.2.1.1.2 - 3.6.12.1.1.2 Nucleophilic Attack on the (Acyloxy)allene at the ß- or .-Position [Seite 121]
1.7.1.2.1.1.2.1 - 3.6.12.1.1.2.1 Method 1: Nucleophilic Attack at the .-Position [Seite 122]
1.7.1.2.1.1.2.2 - 3.6.12.1.1.2.2 Method 2: Nucleophilic Attack at the ß-Position [Seite 125]
1.7.1.2.1.1.3 - 3.6.12.1.1.3 (Acyloxy)allenes as Nucleophiles [Seite 126]
1.7.1.2.1.1.4 - 3.6.12.1.1.4 (Acyloxy)allenes as All-Carbon 1,3-Dipoles [Seite 129]
1.7.1.3 - 3.6.13 Organometallic Complexes of Gold (Update 3) [Seite 132]
1.7.1.3.1 - 3.6.13.1 Gold-Catalyzed Coupling Reactions [Seite 132]
1.7.1.3.1.1 - 3.6.13.1.1 Oxidative Coupling with Gold(III) as a Stoichiometric Oxidant [Seite 132]
1.7.1.3.1.1.1 - 3.6.13.1.1.1 Method 1: Reductive Elimination from Stoichiometric Organogold(III) Complexes [Seite 132]
1.7.1.3.1.1.2 - 3.6.13.1.1.2 Method 2: Oxidative Chlorination of Nonactivated Arenes [Seite 133]
1.7.1.3.1.1.3 - 3.6.13.1.1.3 Method 3: Oxidative Alkynylation of Nonactivated Arenes [Seite 134]
1.7.1.3.1.1.4 - 3.6.13.1.1.4 Method 4: Oxidative Amination of Nonactivated Arenes [Seite 135]
1.7.1.3.1.1.5 - 3.6.13.1.1.5 Method 5: Oxidative Homocoupling via C--H Bond Functionalization [Seite 135]
1.7.1.3.1.1.6 - 3.6.13.1.1.6 Method 6: Homocoupling as a Side Reaction in Cyclizations Catalyzed by Gold(III) [Seite 137]
1.7.1.3.1.2 - 3.6.13.1.2 Gold-Catalyzed Cross Coupling with Substrates as Oxidants [Seite 139]
1.7.1.3.1.2.1 - 3.6.13.1.2.1 Method 1: Gold-Catalyzed Suzuki Reactions [Seite 139]
1.7.1.3.1.2.2 - 3.6.13.1.2.2 Method 2: Gold-Catalyzed Sonogashira Reactions [Seite 140]
1.7.1.3.1.2.3 - 3.6.13.1.2.3 Method 3: Gold-Catalyzed Alkynylation of Heterocycles Using Alkynyliodine(III) Reagents [Seite 142]
1.7.1.3.1.3 - 3.6.13.1.3 Gold-Catalyzed Oxidative Homocoupling with External Oxidants [Seite 146]
1.7.1.3.1.3.1 - 3.6.13.1.3.1 Method 1: Homocoupling of Nonactivated Arenes Using (Diacetoxyiodo)benzene [Seite 147]
1.7.1.3.1.3.2 - 3.6.13.1.3.2 Method 2: Synthesis of Dicoumarins via Cyclization-Homocoupling Using tert-Butyl Hydroperoxide [Seite 148]
1.7.1.3.1.3.3 - 3.6.13.1.3.3 Method 3: Cyclization-Homocoupling of 2-Alkynylphenols with (Diacetoxyiodo)benzene [Seite 149]
1.7.1.3.1.3.4 - 3.6.13.1.3.4 Method 4: Homocoupling of Propargyl Acetates Using Selectfluor [Seite 150]
1.7.1.3.1.3.5 - 3.6.13.1.3.5 Method 5: Homocoupling from Stoichiometric Organogold(I) Complexes Using Electrophilic Fluorinating Reagents [Seite 152]
1.7.1.3.1.4 - 3.6.13.1.4 Gold-Catalyzed Oxidative Cross Coupling with External Oxidants [Seite 153]
1.7.1.3.1.4.1 - 3.6.13.1.4.1 Method 1: Oxidative Alkynylation of Nonactivated Arenes Using (Diacetoxyiodo)benzene [Seite 153]
1.7.1.3.1.4.2 - 3.6.13.1.4.2 Method 2: Oxidative Diamination of Alkenes Using (Diacetoxyiodo)benzene [Seite 155]
1.7.1.3.1.4.3 - 3.6.13.1.4.3 Method 3: Synthesis of 1-Carboxyvinyl Ketones via Oxidative C--O Bond Formation Using Selectfluor [Seite 157]
1.7.1.3.1.4.4 - 3.6.13.1.4.4 Method 4: Oxidative Arylation with Arylboronic Acids Using Selectfluor [Seite 159]
1.7.1.3.1.4.4.1 - 3.6.13.1.4.4.1 Variation 1: Synthesis of a-Aryl Enones from Propargyl Acetates [Seite 159]
1.7.1.3.1.4.4.2 - 3.6.13.1.4.4.2 Variation 2: Oxidative Carboheterofunctionalization of Alkenes [Seite 161]
1.7.1.3.1.4.4.3 - 3.6.13.1.4.4.3 Variation 3: Synthesis of a-Aryl a-Fluoro Ketones via Oxidative Functionalization of Alkynes [Seite 165]
1.7.1.3.1.4.5 - 3.6.13.1.4.5 Method 5: Oxidative Arylation with Arylsilanes Using Selectfluor [Seite 166]
1.7.1.3.1.4.6 - 3.6.13.1.4.6 Method 6: Oxidative Aminooxygenation and Aminoamidation of Alkenes Using Selectfluor or (Diacetoxyiodo)benzene [Seite 167]
1.7.1.3.1.4.7 - 3.6.13.1.4.7 Method 7: Cascade Cyclization-Intramolecular Arylation with Nonactivated Arenes Using External Oxidants [Seite 171]
1.7.1.3.1.4.7.1 - 3.6.13.1.4.7.1 Variation 1: Cascade Cyclization-Intramolecular Arylation of Benzyl-Substituted Allenoates Using Selectfluor [Seite 171]
1.7.1.3.1.4.7.2 - 3.6.13.1.4.7.2 Variation 2: Cascade Cyclization-Intramolecular Arylation of Alkenes [Seite 175]
1.7.1.3.1.4.8 - 3.6.13.1.4.8 Method 8: Cascade Cyclization-Oxidative Alkynylation of Allenoates Using Selectfluor [Seite 178]
1.7.1.3.1.4.9 - 3.6.13.1.4.9 Method 9: Isolation of a Gold(III) Fluoride Complex and Its Use in Cross Coupling [Seite 180]
1.8 - Volume 5: Compounds of Group 14 (Ge, Sn, Pb) [Seite 184]
1.8.1 - 5.2 Product Class 2: Tin Compounds [Seite 184]
1.8.1.1 - 5.2.27 Product Subclass 27: Benzylstannanes [Seite 184]
1.8.1.1.1 - Synthesis of Product Subclass 27 [Seite 184]
1.8.1.1.1.1 - 5.2.27.1 Method 1: Synthesis from (Trialkylstannyl)- or (Triarylstannyl)lithiums [Seite 184]
1.8.1.1.1.1.1 - 5.2.27.1.1 Variation 1: From (Trialkylstannyl)- or (Triarylstannyl)lithiums and Benzyl Halides [Seite 184]
1.8.1.1.1.1.2 - 5.2.27.1.2 Variation 2: From (Trialkylstannyl)lithiums or (Trialkylstannyl)sodiums and a,ß-Unsaturated Esters [Seite 185]
1.8.1.1.1.2 - 5.2.27.2 Method 2: Synthesis from Organomagnesium Derivatives and Organotin Halides [Seite 186]
1.8.1.1.1.2.1 - 5.2.27.2.1 Variation 1: From Benzyl Halides by Barbier Reactions [Seite 186]
1.8.1.1.1.2.2 - 5.2.27.2.2 Variation 2: Sonication-Promoted Barbier Reactions [Seite 187]
1.8.1.1.1.2.3 - 5.2.27.2.3 Variation 3: From Benzyl Halides by Grignard Reactions [Seite 188]
1.8.1.1.1.3 - 5.2.27.3 Method 3: Synthesis from Benzyllithiums and Stannyl Halides [Seite 189]
1.8.1.1.1.3.1 - 5.2.27.3.1 Variation 1: From Benzyllithiums without Directing Groups [Seite 189]
1.8.1.1.1.3.2 - 5.2.27.3.2 Variation 2: From Benzyllithiums with Directing Groups [Seite 191]
1.8.1.1.1.3.3 - 5.2.27.3.3 Variation 3: From Benzyllithiums Prepared by Carbolithiation [Seite 192]
1.8.1.1.1.3.4 - 5.2.27.3.4 Variation 4: From Diastereomerically Enriched Benzyllithiums Containing a Rotationally Restricted Amide [Seite 193]
1.8.1.1.1.3.5 - 5.2.27.3.5 Variation 5: From Diastereomerically Enriched Benzyllithiums Prepared from Enantioenriched Sulfoxides [Seite 194]
1.8.1.1.1.3.6 - 5.2.27.3.6 Variation 6: From Enantiomerically Enriched Benzyllithiums Prepared by Enantioselective Deprotonation [Seite 195]
1.8.1.1.1.4 - 5.2.27.4 Method 4: Synthesis from Benzylzincs and Stannyl Halides [Seite 197]
1.8.1.1.1.4.1 - 5.2.27.4.1 Variation 1: From Benzyl Halides by Barbier Reactions [Seite 197]
1.8.1.1.1.4.2 - 5.2.27.4.2 Variation 2: From Benzylzincs via Transmetalation to Benzylcuprates [Seite 198]
1.8.1.1.1.5 - 5.2.27.5 Method 5: Synthesis from Arylzincs and (Iodomethyl)stannanes [Seite 200]
1.8.1.1.1.6 - 5.2.27.6 Method 6: Synthesis from Stannyl Anion Equivalents and Carbonyl Derivatives [Seite 201]
1.8.1.1.1.6.1 - 5.2.27.6.1 Variation 1: Addition of Stannyllithiums to Aldehydes [Seite 201]
1.8.1.1.1.6.2 - 5.2.27.6.2 Variation 2: Addition of Tributyl(trimethylsilyl)stannane to Aldehydes [Seite 201]
1.8.1.1.1.6.3 - 5.2.27.6.3 Variation 3: Addition of Stannyllithiums or Stannylzincs to Enantiomerically Enriched N-Sulfinylimines [Seite 202]
1.8.1.1.1.7 - 5.2.27.7 Method 7: Palladium-Catalyzed Insertion of Benzyl Halides into Hexaalkyldistannanes [Seite 204]
1.8.1.1.1.8 - 5.2.27.8 Method 8: Synthesis by Silicon-Tin Transmetalation [Seite 205]
1.8.1.1.1.9 - 5.2.27.9 Method 9: Hydrostannylation of Alkenes [Seite 205]
1.8.1.1.1.9.1 - 5.2.27.9.1 Variation 1: Radical Hydrostannylation of Alkenes [Seite 205]
1.8.1.1.1.9.2 - 5.2.27.9.2 Variation 2: Palladium-Catalyzed Hydrostannylation of Alkenes [Seite 206]
1.8.1.1.1.10 - 5.2.27.10 Method 10: Palladium-Catalyzed Distannylation of o-Quinodimethanes [Seite 207]
1.8.1.1.1.11 - 5.2.27.11 Method 11: Synthesis by Sommelet-Hauser Rearrangement of Tetraalkylammonium Salts [Seite 208]
1.8.1.1.2 - Applications of Product Subclass 27 in Organic Synthesis [Seite 210]
1.8.1.1.2.1 - 5.2.27.12 Method 12: Transmetalation [Seite 210]
1.8.1.1.2.1.1 - 5.2.27.12.1 Variation 1: Transmetalation To Afford Alkali Metal Derivatives [Seite 210]
1.8.1.1.2.1.2 - 5.2.27.12.2 Variation 2: Transmetalation To Afford Other Metal Derivatives [Seite 212]
1.8.1.1.2.2 - 5.2.27.13 Method 13: Stille Couplings [Seite 212]
1.8.1.1.2.2.1 - 5.2.27.13.1 Variation 1: Coupling to Aryl Bromides [Seite 212]
1.8.1.1.2.2.2 - 5.2.27.13.2 Variation 2: Coupling to Vinyl Trifluoromethanesulfonates [Seite 213]
1.8.1.1.2.2.3 - 5.2.27.13.3 Variation 3: Coupling to Acyl Chlorides [Seite 214]
1.8.1.1.2.3 - 5.2.27.14 Method 14: Palladium-Free Coupling to a-Oxo Acid Chlorides [Seite 215]
1.8.1.1.2.4 - 5.2.27.15 Method 15: Nucleophilic Addition to N-(Alkoxycarbonyl)pyridinium Salts [Seite 215]
1.8.1.1.2.5 - 5.2.27.16 Method 16: Three-Component Coupling of Imines, Acid Chlorides, and Benzylstannanes [Seite 216]
1.8.1.2 - 5.2.28 Product Subclass 28: Allylstannanes [Seite 220]
1.8.1.2.1 - Synthesis of Product Subclass 28 [Seite 220]
1.8.1.2.1.1 - 5.2.28.1 Method 1: Synthesis from Allylmagnesium Reagents and Stannyl Halides [Seite 220]
1.8.1.2.1.1.1 - 5.2.28.1.1 Variation 1: Via Preformed Allyl Grignards [Seite 221]
1.8.1.2.1.1.2 - 5.2.28.1.2 Variation 2: Via Barbier Reaction [Seite 222]
1.8.1.2.1.1.3 - 5.2.28.1.3 Variation 3: Sonication-Promoted Barbier Reactions [Seite 223]
1.8.1.2.1.1.4 - 5.2.28.1.4 Variation 4: Sonication-Promoted Barbier Reactions with Hexabutyldistannoxane [Seite 224]
1.8.1.2.1.2 - 5.2.28.2 Method 2: Synthesis from Allyllithium Derivatives and Stannyl Halides [Seite 225]
1.8.1.2.1.2.1 - 5.2.28.2.1 Variation 1: Via Alkene Deprotonation [Seite 225]
1.8.1.2.1.2.2 - 5.2.28.2.2 Variation 2: Via Lithium-Halogen Exchange [Seite 227]
1.8.1.2.1.2.3 - 5.2.28.2.3 Variation 3: From Allyl Thioethers [Seite 228]
1.8.1.2.1.2.4 - 5.2.28.2.4 Variation 4: From Enantiomerically Enriched Allyllithiums Prepared by Enantioselective Deprotonation [Seite 229]
1.8.1.2.1.3 - 5.2.28.3 Method 3: Synthesis from Allylzincs and Stannyl Halides [Seite 230]
1.8.1.2.1.4 - 5.2.28.4 Method 4: Synthesis by Silicon-Tin Transmetalation [Seite 232]
1.8.1.2.1.5 - 5.2.28.5 Method 5: Synthesis from Stannyl Anion Equivalents and Allylic Halides, Sulfides, and Methanesulfonates [Seite 233]
1.8.1.2.1.5.1 - 5.2.28.5.1 Variation 1: Via Stannyllithiums [Seite 233]
1.8.1.2.1.5.2 - 5.2.28.5.2 Variation 2: Via Stannylcopper Compounds [Seite 236]
1.8.1.2.1.5.3 - 5.2.28.5.3 Variation 3: Via Stannylpalladium Species [Seite 238]
1.8.1.2.1.6 - 5.2.28.6 Method 6: Synthesis from Allylic Acetates, Benzoates, and Phosphates [Seite 238]
1.8.1.2.1.6.1 - 5.2.28.6.1 Variation 1: Palladium-Catalyzed Reaction of Diethyl(tributylstannyl)aluminum and Allylic Acetates [Seite 238]
1.8.1.2.1.6.2 - 5.2.28.6.2 Variation 2: Palladium-Catalyzed Reaction of Diethyl(tributylstannyl)aluminum and Allylic Phosphates [Seite 239]
1.8.1.2.1.6.3 - 5.2.28.6.3 Variation 3: Palladium-Catalyzed Reduction of Allylic Acetates [Seite 241]
1.8.1.2.1.6.4 - 5.2.28.6.4 Variation 4: Copper-Catalyzed Reaction of Bis(tributylstannyl)zinc and Allylic Benzoates [Seite 241]
1.8.1.2.1.6.5 - 5.2.28.6.5 Variation 5: Palladium-Catalyzed Reaction between Samarium(II) Iodide, Stannyl Halides, and Allylic Acetates [Seite 243]
1.8.1.2.1.7 - 5.2.28.7 Method 7: Synthesis from Allylic Sulfur Derivatives [Seite 244]
1.8.1.2.1.7.1 - 5.2.28.7.1 Variation 1: Via Sulfides [Seite 244]
1.8.1.2.1.7.2 - 5.2.28.7.2 Variation 2: Via Allylic Sulfones [Seite 245]
1.8.1.2.1.7.3 - 5.2.28.7.3 Variation 3: Via Allylic S-Substituted S-Methyl Dithiocarbonates [Seite 248]
1.8.1.2.1.8 - 5.2.28.8 Method 8: Synthesis via Wittig Reaction [Seite 250]
1.8.1.2.1.9 - 5.2.28.9 Method 9: Synthesis of a-Substituted Allylstannanes by Selenoxide Elimination [Seite 252]
1.8.1.2.1.10 - 5.2.28.10 Method 10: Synthesis from Stannyl Anion Equivalents and a,ß-Unsaturated Carbonyl Derivatives [Seite 253]
1.8.1.2.1.10.1 - 5.2.28.10.1 Variation 1: 1,2-Addition to a,ß-Unsaturated Aldehydes and Ketones [Seite 253]
1.8.1.2.1.10.2 - 5.2.28.10.2 Variation 2: 1,4-Addition to a,ß-Unsaturated Ketones Followed by Enamine Formation [Seite 255]
1.8.1.2.1.10.3 - 5.2.28.10.3 Variation 3: Via ß-Stannyl Enolate Esters Prepared by 1,4-Addition to a,ß-Unsaturated Esters [Seite 257]
1.8.1.2.1.11 - 5.2.28.11 Method 11: Synthesis from Allenes [Seite 259]
1.8.1.2.1.11.1 - 5.2.28.11.1 Variation 1: Via Stannylcupration of Allenes [Seite 259]
1.8.1.2.1.11.2 - 5.2.28.11.2 Variation 2: Palladium-Catalyzed Addition of Distannanes and Silastannanes to Allenes [Seite 261]
1.8.1.2.1.11.3 - 5.2.28.11.3 Variation 3: Hydrostannylation of Allenes [Seite 263]
1.8.1.2.1.11.4 - 5.2.28.11.4 Variation 4: Palladium-Catalyzed Acylstannylation of Allenes [Seite 265]
1.8.1.2.1.11.5 - 5.2.28.11.5 Variation 5: Palladium-Catalyzed Distannylation of In Situ Generated Allenes [Seite 266]
1.8.1.2.1.12 - 5.2.28.12 Method 12: Synthesis from Vinylstannanes [Seite 266]
1.8.1.2.1.12.1 - 5.2.28.12.1 Variation 1: From Vinylstannanes and Ethene [Seite 266]
1.8.1.2.1.12.2 - 5.2.28.12.2 Variation 2: Via Lewis Acid Catalyzed Addition of Alkylcuprates to Vinylstannane Acetals [Seite 267]
1.8.1.2.1.13 - 5.2.28.13 Method 13: Synthesis from 1,3-Dienes [Seite 269]
1.8.1.2.1.13.1 - 5.2.28.13.1 Variation 1: Platinum-Catalyzed Silylstannylation of 1,3-Dienes [Seite 269]
1.8.1.2.1.13.2 - 5.2.28.13.2 Variation 2: Nickel-Catalyzed Acylstannylation of 1,3-Dienes [Seite 269]
1.8.1.2.1.14 - 5.2.28.14 Method 14: Synthesis from Allylstannanes [Seite 270]
1.8.1.2.1.14.1 - 5.2.28.14.1 Variation 1: Addition of Organometallic Species to Allylstannyl Halides [Seite 270]
1.8.1.2.1.14.2 - 5.2.28.14.2 Variation 2: Rearrangement of Allylstannanes [Seite 271]
1.8.1.2.1.15 - 5.2.28.15 Method 15: Synthesis by the Hydrolysis of Borylallylic Stannanes [Seite 272]
1.8.1.2.1.16 - 5.2.28.16 Method 16: Additional Methods [Seite 272]
1.8.1.2.2 - Applications of Product Subclass 28 in Organic Synthesis [Seite 274]
1.8.1.2.2.1 - 5.2.28.17 Method 17: Radical Reactions [Seite 274]
1.8.1.2.2.2 - 5.2.28.18 Method 18: Cross-Coupling Reactions [Seite 278]
1.8.1.2.2.3 - 5.2.28.19 Method 19: Transmetalations [Seite 279]
1.8.1.2.2.4 - 5.2.28.20 Method 20: Reactions with Aldehydes, Ketones, and Their Derivatives [Seite 281]
1.8.1.2.2.5 - 5.2.28.21 Method 21: Catalytic Enantioselective Addition to Aldehydes [Seite 285]
1.8.1.2.2.6 - 5.2.28.22 Method 22: Nucleophilic Addition to N-Acyliminium Ions [Seite 287]
1.9 - Volume 9: Fully Unsaturated Small Ring Heterocycles and Monocyclic Five-Membered Hetarenes with One Heteroatom [Seite 292]
1.9.1 - 9.9 Product Class 9: Furans [Seite 292]
1.9.1.1 - 9.9.5 Furans [Seite 292]
1.9.1.1.1 - 9.9.5.1 Synthesis by Ring-Closure Reactions [Seite 294]
1.9.1.1.1.1 - 9.9.5.1.1 By Formation of One O--C and One C--C Bond [Seite 294]
1.9.1.1.1.1.1 - 9.9.5.1.1.1 Fragments O--C--C and C--C [Seite 294]
1.9.1.1.1.1.1.1 - 9.9.5.1.1.1.1 From a-Heterofunctionalized Ketones or Aldehydes [Seite 294]
1.9.1.1.1.1.1.1.1 - 9.9.5.1.1.1.1.1 Method 1: From a-Halo Ketones and 1,3-Dicarbonyl Compounds (Feist-Benary Reaction) [Seite 294]
1.9.1.1.1.1.1.1.2 - 9.9.5.1.1.1.1.2 Method 2: Rhodium-Catalyzed Reaction of a-Diazocarbonyl Compounds with Alkynes [Seite 295]
1.9.1.1.1.1.1.1.3 - 9.9.5.1.1.1.1.3 Method 3: From a-Oxy Ketones or Aldehydes and Dicarbonyl Compounds [Seite 296]
1.9.1.1.1.1.1.1.4 - 9.9.5.1.1.1.1.4 Method 4: From a-Oxyaldehydes and Enones [Seite 296]
1.9.1.1.1.1.1.2 - 9.9.5.1.1.1.2 From 1,3-Dicarbonyl Compounds [Seite 297]
1.9.1.1.1.1.1.2.1 - 9.9.5.1.1.1.2.1 Method 1: From 1,3-Dicarbonyl Compounds and Aldose Sugars [Seite 297]
1.9.1.1.1.1.1.2.2 - 9.9.5.1.1.1.2.2 Method 2: From 1,3-Dicarbonyl Compounds and Propargyl Alcohols [Seite 299]
1.9.1.1.1.1.1.2.3 - 9.9.5.1.1.1.2.3 Method 3: From 1,3-Dicarbonyl Compounds and But-2-ene-1,4-diones [Seite 300]
1.9.1.1.1.1.1.2.4 - 9.9.5.1.1.1.2.4 Method 4: From 1,3-Dicarbonyl Compounds and 1,4-Diphenylbut-2-yne-1,4-dione [Seite 300]
1.9.1.1.1.1.1.2.5 - 9.9.5.1.1.1.2.5 Method 5: From 1,3-Dicarbonyl Compounds and Bromoallenes [Seite 301]
1.9.1.1.1.1.1.2.6 - 9.9.5.1.1.1.2.6 Method 6: From 1,3-Dicarbonyl Compounds and Nitroalkenes [Seite 301]
1.9.1.1.1.1.1.2.7 - 9.9.5.1.1.1.2.7 Method 7: From 1,3-Dicarbonyl Compounds and Alkynoates [Seite 302]
1.9.1.1.1.1.1.3 - 9.9.5.1.1.1.3 From Functionalized Alkenes and Alkynes with C--C--O Building Blocks [Seite 303]
1.9.1.1.1.1.1.3.1 - 9.9.5.1.1.1.3.1 Method 1: From Diethyl Acetylenedicarboxylate and Propargyl Alcohols [Seite 303]
1.9.1.1.1.1.1.3.2 - 9.9.5.1.1.1.3.2 Method 2: From Dimethyl Acetylenedicarboxylate, Aldehydes, and Thiazolium Salts [Seite 303]
1.9.1.1.1.1.2 - 9.9.5.1.1.2 Fragments C--C--C and O--C [Seite 304]
1.9.1.1.1.1.2.1 - 9.9.5.1.1.2.1 Method 1: Cyclization between 2,3-Bis(trimethylsilyl)buta-1,3-diene and Acyl Chlorides [Seite 304]
1.9.1.1.1.1.2.2 - 9.9.5.1.1.2.2 Method 2: From Ketene S,S-Acetals and Aldehydes [Seite 305]
1.9.1.1.1.1.2.3 - 9.9.5.1.1.2.3 Method 3: Reaction between Isocyanides, Dialkyl Acetylenedicarboxylates, and 1-Aryl-2-(arylamino)-2-hydroxyethanones [Seite 306]
1.9.1.1.1.1.2.4 - 9.9.5.1.1.2.4 Method 4: Cyclization between Propargylic Dithioacetals and Aldehydes [Seite 307]
1.9.1.1.1.1.3 - 9.9.5.1.1.3 Fragments O--C--C--C and C [Seite 308]
1.9.1.1.1.1.3.1 - 9.9.5.1.1.3.1 Method 1: From Terminal Ynones and Aldehydes [Seite 308]
1.9.1.1.1.1.3.2 - 9.9.5.1.1.3.2 Method 2: From Enones, Aldehydes, and Isocyanides [Seite 309]
1.9.1.1.1.1.3.3 - 9.9.5.1.1.3.3 Method 3: From 1,3-Dicarbonyl Compounds and Cyclohexyl Isocyanide [Seite 310]
1.9.1.1.1.1.3.4 - 9.9.5.1.1.3.4 Method 4: From a,ß-Unsaturated Carbonyl Compounds and Chromium Carbenes [Seite 310]
1.9.1.1.1.1.3.5 - 9.9.5.1.1.3.5 Method 5: From Alkynyl Ketones and Diazoacetates [Seite 311]
1.9.1.1.1.1.3.6 - 9.9.5.1.1.3.6 Method 6: Rhodium-Catalyzed Hydroformylation of Propargyl Alcohols [Seite 312]
1.9.1.1.1.1.3.7 - 9.9.5.1.1.3.7 Method 7: From Dialkyl Acetylenedicarboxylates, Isocyanides, and Carbonyl Compounds [Seite 312]
1.9.1.1.1.2 - 9.9.5.1.2 By Formation of Two C--C Bonds [Seite 314]
1.9.1.1.1.2.1 - 9.9.5.1.2.1 Fragments C--O--C and C--C [Seite 314]
1.9.1.1.1.2.1.1 - 9.9.5.1.2.1.1 Method 1: Condensation of Dimethyl Diglycolate with Aryl(oxo)acetates [Seite 314]
1.9.1.1.1.2.1.2 - 9.9.5.1.2.1.2 Method 2: Reaction of Carbonyl Ylides and Alkynes [Seite 315]
1.9.1.1.1.3 - 9.9.5.1.3 By Formation of One O--C Bond [Seite 315]
1.9.1.1.1.3.1 - 9.9.5.1.3.1 Fragment O--C--C--C--C [Seite 315]
1.9.1.1.1.3.1.1 - 9.9.5.1.3.1.1 By Cyclization of 1,4-Diheterofunctional C4 Compounds [Seite 315]
1.9.1.1.1.3.1.1.1 - 9.9.5.1.3.1.1.1 Method 1: 1,4-Diazabicyclo[2.2.2]octane-Catalyzed Reaction of a-Halo Carbonyl Compounds with Dimethyl Acetylenedicarboxylate [Seite 316]
1.9.1.1.1.3.1.1.2 - 9.9.5.1.3.1.1.2 Method 2: Reactions Involving N-Heterocyclic Carbenes, Activated Alkynes, and Aldehydes [Seite 316]
1.9.1.1.1.3.1.1.3 - 9.9.5.1.3.1.1.3 Method 3: Cyclization of 1,4-Dicarbonyl Compounds [Seite 317]
1.9.1.1.1.3.1.1.4 - 9.9.5.1.3.1.1.4 Method 4: Cyclization of .-Ketoamides [Seite 318]
1.9.1.1.1.3.1.1.5 - 9.9.5.1.3.1.1.5 Method 5: Cyclization of 4-Hydroxybut-2-enals and 4-Hydroxybut-2-enones [Seite 319]
1.9.1.1.1.3.1.1.6 - 9.9.5.1.3.1.1.6 Method 6: Cyclization of But-2-ene-1,4-diones [Seite 320]
1.9.1.1.1.3.1.1.7 - 9.9.5.1.3.1.1.7 Method 7: Cyclization of Alk-2-yne-1,4-diols [Seite 321]
1.9.1.1.1.3.1.1.8 - 9.9.5.1.3.1.1.8 Method 8: From Alkenyl Aryl Ketones and Dichloromethyl Phenyl Sulfoxide [Seite 322]
1.9.1.1.1.3.1.1.9 - 9.9.5.1.3.1.1.9 Method 9: From Baylis-Hillman Adducts of Alkyl Vinyl Ketones [Seite 323]
1.9.1.1.1.3.1.1.10 - 9.9.5.1.3.1.1.10 Method 10: From .,d-Epoxyacrylates [Seite 324]
1.9.1.1.1.3.1.2 - 9.9.5.1.3.1.2 By Cyclization of Monofunctionalized C4 Compounds [Seite 325]
1.9.1.1.1.3.1.2.1 - 9.9.5.1.3.1.2.1 Method 1: Cyclization of (Z)-2-En-4-yn-1-ols [Seite 325]
1.9.1.1.1.3.1.2.2 - 9.9.5.1.3.1.2.2 Method 2: Cyclization of 2-En-4-yn-1-ones [Seite 326]
1.9.1.1.1.3.1.2.3 - 9.9.5.1.3.1.2.3 Method 3: Cyclization of Pent-4-ynones [Seite 328]
1.9.1.1.1.3.1.2.4 - 9.9.5.1.3.1.2.4 Method 4: Cyclization of But-3-yn-1-ols and 2-Alkynylcycloalk-2-enols [Seite 330]
1.9.1.1.1.3.1.2.5 - 9.9.5.1.3.1.2.5 Method 5: Cyclization of But-3-yn-1-ones [Seite 331]
1.9.1.1.1.3.1.2.6 - 9.9.5.1.3.1.2.6 Method 6: Cyclization of 2-(Alk-1-ynyl)alk-2-en-1-ones [Seite 332]
1.9.1.1.1.3.1.2.7 - 9.9.5.1.3.1.2.7 Method 7: Cyclization of Allenols [Seite 334]
1.9.1.1.1.3.1.2.8 - 9.9.5.1.3.1.2.8 Method 8: Cyclization of Allenones [Seite 336]
1.9.1.1.1.3.1.2.9 - 9.9.5.1.3.1.2.9 Method 9: Cyclization of Alk-3-yne-1,2-diols [Seite 342]
1.9.1.1.1.3.1.2.10 - 9.9.5.1.3.1.2.10 Method 10: Electrophilic Cyclization of Propargylic Oxirane Derivatives [Seite 344]
1.9.1.1.1.3.1.2.11 - 9.9.5.1.3.1.2.11 Method 11: Cyclization of 1-Alkynyl-2,3-epoxy Alcohols [Seite 345]
1.9.1.1.1.3.1.2.12 - 9.9.5.1.3.1.2.12 Method 12: Electrophilic Cyclization of 1-(Alk-1-ynyl)cyclopropyl Ketones [Seite 346]
1.9.1.1.1.3.1.2.13 - 9.9.5.1.3.1.2.13 Method 13: Cyclization of Cyclopropylidene and Cyclopropenyl Ketones [Seite 347]
1.9.1.1.1.3.1.2.14 - 9.9.5.1.3.1.2.14 Method 14: Wacker-Type Oxidative Cyclization of Alkenones [Seite 349]
1.9.1.1.1.3.1.2.15 - 9.9.5.1.3.1.2.15 Method 15: Cyclization of 1,3-Dienyl Ethers or 1,3-Dien-1-ols [Seite 349]
1.9.1.1.1.3.1.2.16 - 9.9.5.1.3.1.2.16 Method 16: Michael-Type Cyclization of 2,4-Unsaturated 1,6-Dicarbonyl Systems [Seite 351]
1.9.1.1.1.3.1.2.17 - 9.9.5.1.3.1.2.17 Method 17: Methylsulfanylation of .-Disulfanyl Carbonyl Compounds [Seite 351]
1.9.1.1.1.3.1.2.18 - 9.9.5.1.3.1.2.18 Method 18: Electrophilic Cyclization of 4-Sulfanylbut-2-yn-1-ols via [1,2]-Migration of the Sulfanyl Group [Seite 352]
1.9.1.1.1.3.1.2.19 - 9.9.5.1.3.1.2.19 Method 19: Cycloisomerization of a-Sulfanyl Allenes [Seite 353]
1.9.1.1.1.3.1.2.20 - 9.9.5.1.3.1.2.20 Method 20: Cyclization of Acetylene-Cobalt Complexes with (Vinyloxy)silanes [Seite 354]
1.9.1.1.1.4 - 9.9.5.1.4 By Formation of One C--C Bond [Seite 354]
1.9.1.1.1.4.1 - 9.9.5.1.4.1 Fragment C--O--C--C--C [Seite 354]
1.9.1.1.1.4.1.1 - 9.9.5.1.4.1.1 Method 1: Cyclization of (2-Cyanovinyloxy)malonates [Seite 354]
1.9.1.1.1.4.1.2 - 9.9.5.1.4.1.2 Method 2: Ring-Closing Metathesis of Homoallylic Enol Ethers [Seite 355]
1.9.1.1.1.4.2 - 9.9.5.1.4.2 Fragment C--C--O--C--C [Seite 355]
1.9.1.1.1.4.2.1 - 9.9.5.1.4.2.1 Method 1: Intramolecular Michael-Type Addition of a 3-Oxa-1,5-enyne [Seite 355]
1.9.1.1.1.4.2.2 - 9.9.5.1.4.2.2 Method 2: Cyclization of 2'-Bromoallylic Propargyl Ethers [Seite 356]
1.9.1.1.1.4.2.3 - 9.9.5.1.4.2.3 Method 3: Palladium-Catalyzed Cycloisomerization of Allyl Propargyl Ethers [Seite 356]
1.9.1.1.1.4.2.4 - 9.9.5.1.4.2.4 Method 4: Reductive Cyclization of Propargyl 2,2,2-Trichloroethyl Ethers [Seite 357]
1.9.1.1.1.4.2.5 - 9.9.5.1.4.2.5 Method 5: Radical Cyclization of Divinyl Ethers [Seite 357]
1.9.1.1.1.4.2.6 - 9.9.5.1.4.2.6 Method 6: Ring-Closing Metathesis of Diallylic Ethers [Seite 358]
1.9.1.1.2 - 9.9.5.2 Synthesis by Ring Transformation [Seite 359]
1.9.1.1.2.1 - 9.9.5.2.1 Ring Enlargement [Seite 359]
1.9.1.1.2.1.1 - 9.9.5.2.1.1 Method 1: Ring-Opening Cycloisomerization of Methylene- or Alkylidenecyclopropyl Ketones [Seite 360]
1.9.1.1.2.2 - 9.9.5.2.2 From Five-Membered Heterocycles [Seite 361]
1.9.1.1.2.2.1 - 9.9.5.2.2.1 Method 1: Ring Opening of 7-Oxabicycles [Seite 361]
1.9.1.1.2.2.2 - 9.9.5.2.2.2 Method 2: Retro-Diels-Alder Reaction of 7-Oxabicyclo[2.2.1]heptadienes [Seite 361]
1.9.1.1.2.2.3 - 9.9.5.2.2.3 Method 3: Intermolecular Cycloaddition of Alkynes to Oxazoles Followed by Retro-Diels-Alder Reaction [Seite 362]
1.9.1.1.2.2.4 - 9.9.5.2.2.4 Method 4: Cycloaddition of 5-Aminopentynoates with Aldehydes and a-Isocyanoacetamides Followed by Retro-Diels-Alder Reaction [Seite 363]
1.9.1.1.2.2.5 - 9.9.5.2.2.5 Method 5: Synthesis from (7-Oxabicyclo[2.2.1]hept-5-en-2-ylidene)-amines by Grob Fragmentation [Seite 364]
1.9.1.1.2.3 - 9.9.5.2.3 Ring Contraction [Seite 365]
1.9.1.1.2.3.1 - 9.9.5.2.3.1 Method 1: Synthesis from Furo[3,4-c]pyranones [Seite 365]
1.9.1.1.2.3.2 - 9.9.5.2.3.2 Method 2: Synthesis from 3,6-Dihydro-1,2-dioxins [Seite 366]
1.9.1.1.2.3.3 - 9.9.5.2.3.3 Method 3: Synthesis from Sugar Derivatives [Seite 366]
1.9.1.1.3 - 9.9.5.3 Aromatization [Seite 367]
1.9.1.1.3.1 - 9.9.5.3.1 Method 1: Synthesis by Elimination [Seite 367]
1.9.1.1.3.2 - 9.9.5.3.2 Method 2: Oxidation of Dihydrofurans [Seite 369]
1.9.1.1.4 - 9.9.5.4 Synthesis by Substituent Modification [Seite 369]
1.9.1.1.4.1 - 9.9.5.4.1 Substitution of Hydrogen [Seite 369]
1.9.1.1.4.1.1 - 9.9.5.4.1.1 Method 1: Introduction of Aminoalkyl Groups with N-Sulfinyl-4-toluene-sulfonamide and Zinc(II) Chloride [Seite 369]
1.9.1.1.4.1.2 - 9.9.5.4.1.2 Method 2: Introduction of a Hydroxymethyl Group by Friedel-Crafts Reaction [Seite 370]
1.9.1.1.4.1.3 - 9.9.5.4.1.3 Method 3: Introduction of Aryl, Alkynyl, Alkyl, or Hydroxymethyl Groups by Addition/Oxidative Rearrangement [Seite 371]
1.9.1.1.4.1.4 - 9.9.5.4.1.4 Method 4: Introduction of Alk-1-enyl Groups by Coupling with Alkenes or Alkynes [Seite 373]
1.9.1.1.4.1.5 - 9.9.5.4.1.5 Method 5: Introduction of Alkyl Groups by Reaction with Activated Alkenes [Seite 374]
1.9.1.1.4.1.6 - 9.9.5.4.1.6 Method 6: Introduction of Aryl Groups by Coupling with Aryl Halides [Seite 376]
1.9.1.1.4.1.7 - 9.9.5.4.1.7 Method 7: Introduction of Alkyl Groups by Lewis Acid or Metal-Catalyzed Reactions [Seite 377]
1.9.1.1.4.1.8 - 9.9.5.4.1.8 Method 8: Introduction of exo-Methylene Groups by Catalytic Inter- or Intramolecular Hydroarylation of Unactivated Triple Bonds [Seite 378]
1.9.1.1.4.1.9 - 9.9.5.4.1.9 Method 9: Introduction of Halogen Substituents [Seite 379]
1.9.1.1.4.1.10 - 9.9.5.4.1.10 Method 10: Ammonium Cerium(IV) Nitrate Catalyzed Radical Dimerization [Seite 379]
1.9.1.1.4.2 - 9.9.5.4.2 Substitution of Metals [Seite 379]
1.9.1.1.4.2.1 - 9.9.5.4.2.1 Method 1: Replacement of Lithium by a Hydroxymethyl Group [Seite 379]
1.9.1.1.4.2.2 - 9.9.5.4.2.2 Method 2: Replacement of Lithium by a Carbonyl Group [Seite 380]
1.9.1.1.4.2.3 - 9.9.5.4.2.3 Method 3: Replacement of Lithium by Alkynyl Groups via Intermediate (Butyltellanyl)furans [Seite 381]
1.9.1.1.4.2.4 - 9.9.5.4.2.4 Method 4: Replacement of Lithium by an Alkyl Group via Intermediate Stannanes (Stille Coupling) [Seite 382]
1.9.1.1.4.2.5 - 9.9.5.4.2.5 Method 5: Replacement of Lithium by an Aryl or Alkynyl Group via Intermediate Boronates (Suzuki Coupling) [Seite 382]
1.9.1.1.4.2.6 - 9.9.5.4.2.6 Method 6: Replacement of Lithium by Deuterium [Seite 384]
1.9.1.1.4.2.7 - 9.9.5.4.2.7 Method 7: Replacement of Lithium or Magnesium by Carbonyl, Aryl, or Alkenyl Groups via Intermediate Furylzinc Compounds [Seite 384]
1.9.1.1.4.2.8 - 9.9.5.4.2.8 Method 8: Replacement of Lithium by an Allyl Group [Seite 385]
1.9.1.1.4.2.9 - 9.9.5.4.2.9 Method 9: Replacement of Lithium by a Silyl Group [Seite 385]
1.9.1.1.4.2.10 - 9.9.5.4.2.10 Method 10: Replacement of Lithium by a Carbonyl Group via a Furyltitanium [Seite 386]
1.9.1.1.4.3 - 9.9.5.4.3 Substitution of Carbon Functionalities [Seite 386]
1.9.1.1.4.3.1 - 9.9.5.4.3.1 Method 1: Curtius Rearrangement of Furan-2-carboxylic Acids [Seite 387]
1.9.1.1.4.4 - 9.9.5.4.4 Substitution of Heteroatoms [Seite 388]
1.9.1.1.4.4.1 - 9.9.5.4.4.1 Method 1: Reaction of Halofurans with Heteroatom Nucleophiles [Seite 388]
1.9.1.1.4.4.2 - 9.9.5.4.4.2 Method 2: Reaction of Halofurans with Carbonyl Electrophiles [Seite 388]
1.9.1.1.4.4.3 - 9.9.5.4.4.3 Method 3: Reactions of Halofurans with Alkenes [Seite 389]
1.9.1.1.4.4.4 - 9.9.5.4.4.4 Method 4: Nucleophilic Aromatic Substitution of Activated 2-Methoxyfurans with Grignard Reagents [Seite 389]
1.9.1.1.4.5 - 9.9.5.4.5 Modification of a-Substituents [Seite 390]
1.9.1.1.4.5.1 - 9.9.5.4.5.1 Method 1: Multicomponent Type II Anion Relay Chemistry of 2-(tert-Butyldimethylsilyl)furan-3-carbaldehyde [Seite 390]
1.9.1.1.4.5.2 - 9.9.5.4.5.2 Method 2: Wittig Rearrangement of 3-Furylmethyl Ethers [Seite 390]
1.9.1.1.4.5.3 - 9.9.5.4.5.3 Method 3: Ene Reaction of 2-Methylene-2,3-dihydrofurans [Seite 391]
1.9.1.1.4.5.4 - 9.9.5.4.5.4 Method 4: Pummerer-Type Reaction of (Phenylsulfinyl)furans [Seite 392]
1.9.1.1.4.5.5 - 9.9.5.4.5.5 Method 5: 1,5-Electrocyclization of Carbene-Derived Ylides from N-(2-Furylmethylene)anilines [Seite 393]
1.9.2 - 9.10 Product Class 10: Thiophenes, Thiophene 1,1-Dioxides, and Thiophene 1-Oxides [Seite 402]
1.9.2.1 - 9.10.4 Thiophenes, Thiophene 1,1-Dioxides, and Thiophene 1-Oxides [Seite 402]
1.9.2.1.1 - 9.10.4.1 Thiophenes [Seite 402]
1.9.2.1.1.1 - 9.10.4.1.1 Synthesis by Ring-Closure Reactions [Seite 402]
1.9.2.1.1.1.1 - 9.10.4.1.1.1 By Formation of Two S--C Bonds and One C--C Bond [Seite 402]
1.9.2.1.1.1.1.1 - 9.10.4.1.1.1.1 Fragment S and Two C--C Fragments [Seite 402]
1.9.2.1.1.1.1.1.1 - 9.10.4.1.1.1.1.1 Method 1: Synthesis from a Diphosphorylacetylene and Sodium Hydrosulfide Hydrate [Seite 402]
1.9.2.1.1.1.2 - 9.10.4.1.1.2 By Formation of Two S--C Bonds [Seite 403]
1.9.2.1.1.1.2.1 - 9.10.4.1.1.2.1 Fragments C--C--C--C and S [Seite 403]
1.9.2.1.1.1.2.1.1 - 9.10.4.1.1.2.1.1 Method 1: Reaction of a,ß-Unsaturated Nitriles with Sulfur (The Gewald Synthesis) [Seite 403]
1.9.2.1.1.1.3 - 9.10.4.1.1.3 By Formation of Two C--C Bonds [Seite 404]
1.9.2.1.1.1.3.1 - 9.10.4.1.1.3.1 Fragments C--S--C and C--C [Seite 404]
1.9.2.1.1.1.3.1.1 - 9.10.4.1.1.3.1.1 Method 1: Reaction of 3-Thia-1,5-dicarbonyl Compounds or Equivalents with 1,2-Dicarbonyl Compounds (The Hinsberg Synthesis) [Seite 404]
1.9.2.1.1.2 - 9.10.4.1.2 Synthesis by Substituent Modification [Seite 406]
1.9.2.1.1.2.1 - 9.10.4.1.2.1 Substitution of Hydrogen [Seite 406]
1.9.2.1.1.2.1.1 - 9.10.4.1.2.1.1 Method 1: Hydrogen-Deuterium Exchange [Seite 406]
1.9.2.1.1.2.1.2 - 9.10.4.1.2.1.2 Method 2: Introduction of Formyl Groups [Seite 406]
1.9.2.1.1.2.1.2.1 - 9.10.4.1.2.1.2.1 Variation 1: Formylation with Hexamethylenetetramine in Polyphosphoric Acid [Seite 406]
1.9.2.1.1.2.1.2.2 - 9.10.4.1.2.1.2.2 Variation 2: Metalation of Thiophenes Followed by Formylation with N-Formylpiperidine [Seite 407]
1.9.2.1.1.2.1.3 - 9.10.4.1.2.1.3 Method 3: Introduction of Acyl Groups [Seite 408]
1.9.2.1.1.2.1.3.1 - 9.10.4.1.2.1.3.1 Variation 1: Acylation of Thiophene with Anhydrides [Seite 408]
1.9.2.1.1.2.1.3.2 - 9.10.4.1.2.1.3.2 Variation 2: Acylation of Thiophene with Acyl Chlorides [Seite 409]
1.9.2.1.1.2.1.3.3 - 9.10.4.1.2.1.3.3 Variation 3: Acylation of Thiophene with an Ester [Seite 410]
1.9.2.1.1.2.1.3.4 - 9.10.4.1.2.1.3.4 Variation 4: Acylation of Thiophene with Carboxylic Acids [Seite 410]
1.9.2.1.1.2.1.4 - 9.10.4.1.2.1.4 Method 4: Introduction of Chloromethyl Groups [Seite 411]
1.9.2.1.1.2.1.5 - 9.10.4.1.2.1.5 Method 5: Introduction of Alkylamino Groups [Seite 412]
1.9.2.1.1.2.1.6 - 9.10.4.1.2.1.6 Method 6: Introduction of Allyl, Alk-1-enyl, or Alk-1-ynyl Groups [Seite 413]
1.9.2.1.1.2.1.7 - 9.10.4.1.2.1.7 Method 7: Introduction of Aryl Groups [Seite 414]
1.9.2.1.1.2.1.7.1 - 9.10.4.1.2.1.7.1 Variation 1: One-Pot C--H Borylation/Suzuki-Miyaura Cross Coupling [Seite 414]
1.9.2.1.1.2.1.7.2 - 9.10.4.1.2.1.7.2 Variation 2: Palladium-Catalyzed Direct Arylation [Seite 416]
1.9.2.1.1.2.1.8 - 9.10.4.1.2.1.8 Method 8: Introduction of Alkyl Groups [Seite 417]
1.9.2.1.1.2.1.8.1 - 9.10.4.1.2.1.8.1 Variation 1: Gold(III)-Catalyzed Intermolecular Hydroarylation [Seite 417]
1.9.2.1.1.2.1.8.2 - 9.10.4.1.2.1.8.2 Variation 2: Dichlorobis(.5-cyclopentadienyl)zirconium(IV)-Catalyzed Alkylation [Seite 417]
1.9.2.1.1.2.1.8.3 - 9.10.4.1.2.1.8.3 Variation 3: Friedel-Crafts Alkylation of Thiophenes [Seite 418]
1.9.2.1.1.2.1.9 - 9.10.4.1.2.1.9 Method 9: Halogenation [Seite 419]
1.9.2.1.1.2.1.10 - 9.10.4.1.2.1.10 Method 10: Nitration [Seite 420]
1.9.2.1.1.2.2 - 9.10.4.1.2.2 Substitution of Metals [Seite 421]
1.9.2.1.1.2.2.1 - 9.10.4.1.2.2.1 Method 1: Substitution Reactions Involving Organostannanes (The Stille Reaction) [Seite 421]
1.9.2.1.1.2.2.2 - 9.10.4.1.2.2.2 Method 2: Substitution Reactions Involving Organozinc Derivatives (The Negishi Reaction) [Seite 422]
1.9.2.1.1.2.2.3 - 9.10.4.1.2.2.3 Method 3: Substitution Reactions Involving Organoboron Derivatives (The Suzuki Reaction) [Seite 423]
1.9.2.1.1.2.2.4 - 9.10.4.1.2.2.4 Method 4: Substitution Reactions Involving Organomagnesium Derivatives (The Kumada Reaction) [Seite 425]
1.9.2.1.1.2.3 - 9.10.4.1.2.3 Substitution of Heteroatoms [Seite 426]
1.9.2.1.1.2.3.1 - 9.10.4.1.2.3.1 Method 1: Substitution of Halogens by Hydrogen [Seite 426]
1.9.2.1.1.2.3.2 - 9.10.4.1.2.3.2 Method 2: Substitution of Halogens by Alkoxy Groups [Seite 427]
1.9.2.1.1.2.3.3 - 9.10.4.1.2.3.3 Method 3: Metal-Assisted Cross Coupling of Halothiophenes with Alkenes [Seite 427]
1.9.2.1.1.2.3.3.1 - 9.10.4.1.2.3.3.1 Variation 1: Cross Coupling of Halothiophenes with Alkenes in the Presence of a Palladium/Tetraphosphine Catalyst [Seite 427]
1.9.2.1.1.2.3.3.2 - 9.10.4.1.2.3.3.2 Variation 2: Cross Coupling of Halothiophenes with Alkenes in the Presence of Palladium-Containing Nanostructured Silica Functionalized with Pyridine Sites [Seite 428]
1.9.2.1.1.2.3.3.3 - 9.10.4.1.2.3.3.3 Variation 3: Palladium-Catalyzed Heck Reactions of Halothiophenes with Electron-Rich Alkenes in an Ionic Liquid [Seite 429]
1.9.2.1.1.2.3.4 - 9.10.4.1.2.3.4 Method 4: Metal-Assisted Cross Coupling of Halothiophenes with Arenes [Seite 430]
1.9.2.1.1.2.3.4.1 - 9.10.4.1.2.3.4.1 Variation 1: Suzuki Cross Coupling of Halothiophenes with Arenes in the Presence of a Palladium/Tetraphosphine Catalyst [Seite 430]
1.9.2.1.1.2.3.4.2 - 9.10.4.1.2.3.4.2 Variation 2: Suzuki Cross Coupling of Halothiophenes with Arenes in the Presence of a Biarylmonophosphine Ligand [Seite 431]
1.9.2.1.1.2.3.4.3 - 9.10.4.1.2.3.4.3 Variation 3: Site-Selective Suzuki-Miyaura Reactions of 2,3,5-Tribromothiophene [Seite 432]
1.9.2.1.1.2.3.4.4 - 9.10.4.1.2.3.4.4 Variation 4: Suzuki-Type Cross Coupling of Halothiophenes with Arenes in the Presence of Boronates [Seite 434]
1.9.2.1.1.2.3.4.5 - 9.10.4.1.2.3.4.5 Variation 5: Stille Cross Coupling of Halothiophenes with Organostannanes in the Presence of a ß-Oxoiminate(phosphine)palladium Catalyst [Seite 435]
1.9.2.1.1.2.3.5 - 9.10.4.1.2.3.5 Method 5: Metal-Assisted Cross Coupling of Halothiophenes with Alkynes [Seite 436]
1.9.2.1.1.2.3.6 - 9.10.4.1.2.3.6 Method 6: Palladium-Catalyzed Cyanation Reactions of Halothiophenes [Seite 437]
1.9.2.1.1.2.3.7 - 9.10.4.1.2.3.7 Method 7: Copper-Catalyzed Amination of Halothiophenes [Seite 439]
1.9.2.1.1.2.3.8 - 9.10.4.1.2.3.8 Method 8: Substitution of Diaryliodonium Bromides [Seite 440]
1.9.2.1.1.2.4 - 9.10.4.1.2.4 Modification of a-Substituents [Seite 440]
1.9.2.1.1.2.4.1 - 9.10.4.1.2.4.1 Method 1: Mitsunobu Reaction of Thiophenones [Seite 440]
1.9.2.1.1.2.4.2 - 9.10.4.1.2.4.2 Method 2: Decarboxylation [Seite 442]
1.9.2.1.2 - 9.10.4.2 Oligothiophenes [Seite 443]
1.9.2.1.2.1 - 9.10.4.2.1 Synthesis by Ring-Closure Reactions [Seite 443]
1.9.2.1.2.1.1 - 9.10.4.2.1.1 By Formation of Two S--C Bonds [Seite 443]
1.9.2.1.2.1.1.1 - 9.10.4.2.1.1.1 Fragments C--C--C--C and S [Seite 443]
1.9.2.1.2.1.1.1.1 - 9.10.4.2.1.1.1.1 Method 1: Reaction of Buta-1,3-diynes with Sulfides as Sulfuration Reagents [Seite 443]
1.9.2.1.2.1.1.1.2 - 9.10.4.2.1.1.1.2 Method 2: Reaction of 1,4-Diketones with Sulfur Reagents and Cyclization [Seite 444]
1.9.2.1.2.2 - 9.10.4.2.2 Synthesis by Ring Transformation [Seite 445]
1.9.2.1.2.2.1 - 9.10.4.2.2.1 Ring Contraction [Seite 445]
1.9.2.1.2.2.1.1 - 9.10.4.2.2.1.1 Method 1: Synthesis from 1,2-Dithiins by Oxidative Coupling/Dechalcogenation with Copper Nanopowder [Seite 445]
1.9.2.1.2.3 - 9.10.4.2.3 Synthesis by Substituent Modification [Seite 447]
1.9.2.1.2.3.1 - 9.10.4.2.3.1 Substitution of Hydrogen [Seite 447]
1.9.2.1.2.3.1.1 - 9.10.4.2.3.1.1 Method 1: Oxidative Coupling Reactions [Seite 447]
1.9.2.1.2.3.1.2 - 9.10.4.2.3.1.2 Method 2: Direct Arylation Methods Involving Metal Catalysis [Seite 451]
1.9.2.1.2.3.1.2.1 - 9.10.4.2.3.1.2.1 Variation 1: Aryl--Aryl Bond Formation via Coupling of Two C--H Bonds [Seite 451]
1.9.2.1.2.3.2 - 9.10.4.2.3.2 Substitution of Metals [Seite 451]
1.9.2.1.2.3.2.1 - 9.10.4.2.3.2.1 Method 1: Substitution Reactions Involving Organostannanes (The Stille Reaction) [Seite 451]
1.9.2.1.2.3.2.1.1 - 9.10.4.2.3.2.1.1 Variation 1: Palladium-Catalyzed Stille Cross-Coupling Reactions [Seite 451]
1.9.2.1.2.3.2.1.2 - 9.10.4.2.3.2.1.2 Variation 2: Palladium-Catalyzed, Copper(II) Oxide Modified Stille Cross-Coupling Reactions [Seite 454]
1.9.2.1.2.3.2.1.3 - 9.10.4.2.3.2.1.3 Variation 3: Palladium-Catalyzed, Solid-Phase Stille Cross-Coupling Reactions [Seite 455]
1.9.2.1.2.3.2.2 - 9.10.4.2.3.2.2 Method 2: Substitution Reactions Involving Organozinc Derivatives [Seite 456]
1.9.2.1.2.3.2.3 - 9.10.4.2.3.2.3 Method 3: Substitution Reactions Involving Organoboron Derivatives (The Suzuki Reaction) [Seite 458]
1.9.2.1.2.3.2.3.1 - 9.10.4.2.3.2.3.1 Variation 1: Tetrakis(triphenylphosphine)palladium(0)-Assisted Suzuki Cross Coupling under Basic Conditions [Seite 458]
1.9.2.1.2.3.2.3.2 - 9.10.4.2.3.2.3.2 Variation 2: Microwave-Assisted Palladium Catalysis Using Silica- and Chitosan-Supported Palladium Complexes [Seite 460]
1.9.2.1.2.3.2.3.3 - 9.10.4.2.3.2.3.3 Variation 3: A "Base-Free" Tetrakis(triphenylphosphine)palladium(0)-Assisted Suzuki Cross-Coupling Protocol Involving a Triethylborate Salt [Seite 461]
1.9.2.1.2.3.2.4 - 9.10.4.2.3.2.4 Method 4: Substitution Reactions Involving Organomagnesium Derivatives [Seite 463]
1.9.2.1.2.3.3 - 9.10.4.2.3.3 Substitution of Heteroatoms [Seite 464]
1.9.2.1.2.3.3.1 - 9.10.4.2.3.3.1 Method 1: Introduction of Aryl Groups [Seite 464]
1.9.2.1.2.3.3.2 - 9.10.4.2.3.3.2 Method 2: Palladium-Assisted Coupling Reactions [Seite 465]
1.9.2.1.3 - 9.10.4.3 Thiophene 1,1-Dioxides [Seite 466]
1.9.2.1.3.1 - 9.10.4.3.1 Synthesis by Ring Transformation [Seite 466]
1.9.2.1.3.1.1 - 9.10.4.3.1.1 Oxidation [Seite 466]
1.9.2.1.3.1.1.1 - 9.10.4.3.1.1.1 Method 1: Oxidation of Thiophenes [Seite 466]
1.9.2.1.3.2 - 9.10.4.3.2 Aromatization [Seite 468]
1.9.2.1.3.2.1 - 9.10.4.3.2.1 Method 1: Synthesis from 3-Hydroxy-2,3-dihydrothieno[3,2-b]thiophene-1,1-Dioxides by Dehydration [Seite 468]
1.10 - Volume 20: Three Carbon--Heteroatom Bonds: Acid Halides [Seite 476]
1.10.1 - 20.5 Product Class 5: Carboxylic Acid Esters [Seite 476]
1.10.1.1 - 20.5.1.7.15 Synthesis with Retention of the Functional Group [Seite 476]
1.10.1.1.1 - 20.5.1.7.15.1 Conjugate Addition to a,ß-Unsaturated Esters [Seite 476]
1.10.1.1.1.1 - 20.5.1.7.15.1.1 Method 1: Conjugate Addition of Organometallic Reagents [Seite 476]
1.10.1.1.1.1.1 - 20.5.1.7.15.1.1.1 Variation 1: Conjugate Addition of Organocopper Reagents [Seite 476]
1.10.1.1.1.1.2 - 20.5.1.7.15.1.1.2 Variation 2: Conjugate Addition of Grignard Reagents [Seite 478]
1.10.1.1.1.1.3 - 20.5.1.7.15.1.1.3 Variation 3: Conjugate Addition of Organolithium Reagents [Seite 481]
1.10.1.1.1.2 - 20.5.1.7.15.1.2 Method 2: Conjugate Addition of Other Carbon Nucleophiles [Seite 483]
1.10.1.1.1.2.1 - 20.5.1.7.15.1.2.1 Variation 1: Conjugate Addition of Enolates [Seite 483]
1.10.1.1.1.2.2 - 20.5.1.7.15.1.2.2 Variation 2: Conjugate Addition of Malonates and Derivatives [Seite 484]
1.10.1.1.1.2.3 - 20.5.1.7.15.1.2.3 Variation 3: Conjugate Addition of Terminal Alkynes [Seite 485]
1.10.1.1.1.3 - 20.5.1.7.15.1.3 Method 3: Conjugate Addition of Organosilane Reagents [Seite 485]
1.10.1.1.1.4 - 20.5.1.7.15.1.4 Method 4: Conjugate Addition of Organoborane Reagents [Seite 486]
1.10.1.1.1.5 - 20.5.1.7.15.1.5 Method 5: Conjugate Addition of Boronate Derivatives [Seite 490]
1.10.1.1.1.6 - 20.5.1.7.15.1.6 Method 6: Conjugate Addition of Amines [Seite 491]
1.10.1.1.1.7 - 20.5.1.7.15.1.7 Method 7: Conjugate Addition of O- and S-Nucleophiles [Seite 494]
1.11 - Volume 39: Sulfur, Selenium, and Tellurium [Seite 500]
1.11.1 - 39.1 Product Class 1: Alkanesulfonic Acids and Acyclic Derivatives [Seite 500]
1.11.1.1 - 39.1.15 Alkanesulfonic Acids and Acyclic Derivatives [Seite 500]
1.11.1.1.1 - 39.1.15.1 Applications of Alkanesulfonyl Halides in Organic Synthesis [Seite 500]
1.11.1.1.1.1 - 39.1.15.1.1 Method 1: Protection of Alcohols [Seite 500]
1.11.1.1.1.2 - 39.1.15.1.2 Method 2: Protection of Amines [Seite 501]
1.11.1.1.1.3 - 39.1.15.1.3 Method 3: Synthesis of Alkanethiols [Seite 501]
1.11.1.1.1.4 - 39.1.15.1.4 Method 4: Synthesis of Dialkyl Disulfides [Seite 501]
1.11.1.1.1.5 - 39.1.15.1.5 Method 5: Synthesis of Sulfinic Acids and Salts [Seite 502]
1.11.1.1.1.6 - 39.1.15.1.6 Method 6: Synthesis of Alkanesulfinate Esters [Seite 502]
1.11.1.1.1.7 - 39.1.15.1.7 Method 7: Synthesis of Alkanethiosulfonic Acids and Alkanethiosulfinate Esters [Seite 502]
1.11.1.1.1.8 - 39.1.15.1.8 Method 8: Synthesis of Sulfones [Seite 502]
1.11.1.1.1.8.1 - 39.1.15.1.8.1 Variation 1: Reactions of Alkanesulfonyl Chlorides with Organometallic Compounds [Seite 502]
1.11.1.1.1.8.2 - 39.1.15.1.8.2 Variation 2: Synthesis of Alkyl Aryl Sulfones [Seite 504]
1.11.1.1.1.8.3 - 39.1.15.1.8.3 Variation 3: Addition of Sulfonyl Halides to Multiple Bonds [Seite 505]
1.11.1.1.1.8.4 - 39.1.15.1.8.4 Variation 4: Synthesis of ß-Substituted Sulfones [Seite 506]
1.11.1.1.1.9 - 39.1.15.1.9 Method 9: Synthesis of Sulfur Heterocycles [Seite 511]
1.11.1.1.1.10 - 39.1.15.1.10 Method 10: Formation of C--C Bonds Using Alkanesulfonyl Halides [Seite 517]
1.11.1.1.1.11 - 39.1.15.1.11 Method 11: Formation of C==C Bonds Using Alkanesulfonyl Halides [Seite 521]
1.11.1.1.1.12 - 39.1.15.1.12 Method 12: Transformation of Alcohols into Alkyl Chlorides and Chlorination Reactions [Seite 524]
1.11.1.1.1.13 - 39.1.15.1.13 Method 13: Cyclization Reactions via Acyliminium Ion Formation [Seite 526]
1.11.1.1.1.14 - 39.1.15.1.14 Method 14: Pyrrolidine Ring Formation [Seite 527]
1.11.1.1.1.15 - 39.1.15.1.15 Method 15: Epoxide Ring Formation [Seite 527]
1.11.1.1.1.16 - 39.1.15.1.16 Method 16: Lactone Inversion [Seite 528]
1.11.1.1.1.17 - 39.1.15.1.17 Method 17: Formation of Aldehydes via Rearrangement of Thioacetals [Seite 528]
1.12 - Author Index [Seite 532]
1.13 - Abbreviations [Seite 556]
1.14 - List of All Volumes [Seite 562]
3.6.11 Organometallic Complexes of Gold (Update 1, 2011)
V. López-Carrillo and A. M. Echavarren
3.6.11.1 Gold-Catalyzed Cycloisomerizations of Enynes
Gold(I) salts and complexes are the most alkynophilic amongst the electrophilic metals that catalyze cyclization of 1,n-enynes.[1–13] Gold(I) complexes are highly selective Lewis acids with a high affinity for π-bonds linked to relativistic effects, which reach a maximum with gold.[6,14–16] In the reactions of 1,6-enynes 1, the alkyne group is selectively activated by a cationic gold species {[AuL]+} to form an alkyne–gold(I) complex, which reacts intramolecularly with the alkene by formal 5-exo-dig or 6-endo-dig cyclization to form intermediates 2 and 3, respectively (▶ Scheme 1).[1] A number of alkyne–gold complexes have been characterized[17–21] and studied in solution.[22–25]
▶ Scheme 1 General Reaction Pathways in the Gold(I)-Catalyzed Cyclization of 1,6-Enynes
Although the vast majority of cyclizations of 1,n-enynes catalyzed by gold(I) can be explained by the selective activation of the alkyne function by gold, complexes of gold(I) with the alkene function of the enyne are actually formed in solution in equilibrium with the alkyne–gold complexes.[26] Indeed, well-characterized complexes of gold(I) with alkenes are known[27–42] and their structures have been studied in solution.[39,40,43,44] The solid-state structure of a cationic allene–gold(I) complex has also been determined.[45]
Formation of C—C bonds can be catalyzed by gold(I) or gold(III) salts or complexes. However, gold(III) may be reduced to gold(I) by easily oxidizable substrates.[46] The most widely used catalysts are cationic complexes [Au(S)(L)]X (L = ligand; S = solvent or substrate molecule) generated in situ by chloride abstraction from complexes [AuCl(L)]. Thus, the precatalyst chloro(triphenylphosphine)gold(I) (or other similar phosphine complex) reacts with 1 equivalent of a silver salt with a noncoordinating anion to generate in situ the cationic catalyst {[Au(PPh3)(S)]X}.[47,48] Similar cationic complexes can be obtained in situ by cleavage of the Au—Me bond in methyl(triphenylphosphine)gold(I) with a protic acid.[47,49–51] More conveniently, a cationic complex {[Au(NCMe)(PPh3)]SbF6} has been prepared as a stable crystalline solid, which allows gold(I)-catalyzed reactions to be performed in the absence of silver salts.[47] A gold–oxo complex {[(Ph3PAu)3O]BF4}[52,53] has also been used as a catalyst in reactions of enynes.[54]
Gold(I) complexes 4–7 bearing bulky, biphenyl-based phosphines, which have been shown to be excellent ligands for palladium-catalyzed reactions,[55,56] lead to active catalysts upon activation with silver(I) salts (▶ Scheme 2).[57] More convenient as catalysts are cationic complexes 8–11, which are stable crystalline solids that can be handled under ordinary conditions,[58,59] yet are very reactive as catalysts in a variety of transformations.[60–63] Related complexes 12 and 13 with a weakly coordinated bis(trifluoromethylsulfonyl)amide ligand have also been prepared.[64] Gold complexes with highly electrondonating N-heterocyclic carbene ligands[65–67] such as 14–17 are also good precatalysts.[57,68–72] Cationic species 18 and 19,[73] and related complexes,[74,75] as was well as neutral species 20 and 21[76,77] bearing the 1,3-dimesitylimidazol-2-ylidene (IMes) and 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) N-heterocyclic carbene ligands are active catalysts in many applications. A hydroxygold(I) complex [Au(OH)(IPr)] can also be used as a precatalyst that can be activated with Brønsted acids.[78,79] Open carbenes[80–84] and other related carbenes[20,85–88] also give rise to selective catalysts of moderate electro-philicity. Gold(I) complexes with less donating phosphite or phosphoramidite ligands are the most electrophilic catalysts.[89,90] In particular, readily available complex 22/silver(I) hexafluoroantimonate[91] and its cationic relative 23, bearing tris(2,4-di-tert-butylphenyl)phosphite, are amongst the most reactive gold(I) complexes for the activation of alkynes.[68]
▶ Scheme 2 Selected Gold(I) Complexes Used as Catalysts or Precatalysts
3.6.11.1.1 Method 1: Cycloisomerization of 1,6-Enynes
3.6.11.1.1.1 Variation 1: Formation of 1,3-Dienes
In contrast to palladium(II), platinum(II),[92–95] and ruthenium(II),[94] gold(I) does not undergo oxidative addition under mild conditions.[6,47,96–98] In the absence of nucleophiles, 1,6-enynes usually undergo various types of skeletal rearrangement reactions by fully intra-molecular processes using a variety of electrophilic metal catalysts.[2–4] The major pathways lead to 1,3-dienes 24 and/or 25, reactions known as single-cleavage and double-cleavage rearrangements (▶ Scheme 3).[92,93,99–120] These rearrangement reactions proceed under milder conditions using gold(I) catalysts.[47,48,96] For gold(I), the rearrangement is proposed to proceed via intermediates 2 (see ▶ Scheme 1, Section 3.6.11.1),[97,121] by a mechanism that is consistent with previous work.[99,100,105,114,122–124] Products 26 of a different type of skeletal rearrangement were originally obtained using gold(I) catalysts,[120,125] although this type of compound has since also been obtained using indium(III) chloride[109,110] or iron(III)[96] or ruthenium(II) catalysts.[126] Similar products have also been observed in the reaction of Z-4,6-dien-1-yl-3-ol derivatives with gold or platinum catalysts.[127,128]
▶ Scheme 3 Gold(I)-Catalyzed Skeletal Rearrangement of 1,6-Enynes
None of the key intermediates involved in the skeletal rearrangement has been spectroscopically characterized,[129] although a gold carbene with an N-heterocyclic carbene ligand has been formed in the gas phase and its reactivity with alkenes has been studied.[130–133] Therefore, the structures of these species are based on density functional theory (DFT) calculations. Some of these intermediates are depicted for convenience as gold carbenes, since backbonding in gold(I) has been shown to be not insignificant.[5,6,134,135] However, according to theoretical calculations, these are highly delocalized structures.[97,121,136,137] In the case of cyclopropyl-containing gold carbenes 2 (see ▶ Scheme 1, Section 3.6.11.1), these can also be viewed as delocalized cyclopropylmethyl/cyclobutyl/homoallyl carbocations[138] stabilized by gold.[97,121]
Single-cleavage rearrangement reactions of enynes 27 are stereospecific transformations that proceed under mild conditions to give cyclized products 28 (▶ Scheme 4).[96] Using cationic catalysts 8 or 9 containing bulky phosphine ligands, the rearrangements take place smoothly at temperatures as low as –40 to –60 °C.[121] Similar transformations have been carried out with other gold(I) catalysts.[64,77,139] However, as an exception, enynes such as 29 and 31 with strongly electron-donating groups at the alkene terminus lead to dienes 30 and 32, respectively, with a Z configuration, regardless of the configuration of the starting enynes (▶ Scheme 5).[140]
▶ Scheme 4...
