Intramolecular Anti-Hydrosilylation and Silicon-Assisted Cross-Coupling: Highly Regio- and Stereoselective Synthesis of Trisubstituted Homoallylic Alcohols

A highly regio- and stereoselective anti-intramolecular hydrosilylation of alkynyl silyl ethers catalyzed by a ruthenium arene complex has been developed. The resultant (Z)-alkylidenesilacyclopentanes are efficiently coupled with aryl or alkenyl halides in the presence of tetrabutylammonium fluoride and a palladium(0) catalyst. The yields are generally good, and the reaction is compatible with a wide range of functional groups. The overall transformation achieves the stereoselective conversion of homopropargyl alcohols to trisubstituted homoallylic alcohols. [reaction: see text]