Synthetic Transformations of Vinyl and Aryl Triflates

The increasing use of vinyl and aryl trifluoromethanesulfonates (triflates) is due to their facile preparation from carbonyl compounds and phenols. They undergo cross-coupling reactions with organometallics as the corresponding organic halides or addition reactions to alkenes and alkynes. Especially in the Heck reaction triflates proved to be superior to halides with respect to regio- and diastereoselectivity. Palladium-catalyzed carbon monoxide insertion of triflates leading to the corresponding esters or amides has found widespread application in natural product synthesis. Various deoxygenation procedures for ketones or phenols are based on the ease of removal of the trifluoromethanesulfoxy group. 1. Introduction 2. Synthesis of Vinyl and Aryl Triflates (Nonaflates, Fluorosulfonates) 3. Synthetic Transformations of Vinyl and Aryl Triflates 3.1. Carbon-Carbon Bond Formation 3.1.1. Cross-Coupling Reactions of Vinyl and Aryl Triflates with Organometallics 3.1.2. Cross-Coupling Reactions of Vinyl and Aryl Triflates with Alkenes, Alkynes, Allenes, Cyclopropanes and Ketene Silyl Acetals 3.1.3. Reactions of Vinyl and Aryl Triflates under CO Insertion 3.1.4. Reactions of Vinyl and Aryl Triflates with Cyanides 3.1.5. Reactions of Vinyl Triflates with Aldehydes (Nozaki-Hiyama Reaction) 3.1.6. Carbon-Carbon Bond Formation via Cationic Intermediates 3.2. Carbon-Tin Bond Formation 3.3. Carbon-Nitrogen Bond Formation 3.4. Carbon-Phosphorus Bond Formation 3.5. Carbon-Sulfur Bond Formation 3.6. Carbon-Halogen Bond Formation 3.7. Hydrogenation of Vinyl and Aryl Triflates or Nonaflates 3.8. Special Reactions 4. Conclusion Abbreviations: dba dibenzylidenacetone dppb bis(diphenylphosphino)butane dppp bis(diphenylphosphino)propane dppf diphenylphosphinoferrocene Bn benzyl TBDMS tert-butyldimethylsilyl Tf triflate Nf nonaflate