Co/Fe Dual Catalysis for Sequential Hydrosilylation–Isomerization: Access to Trisubstituted (E)‐Alkenyl Silanes from Terminal Alkynes

Comprehensive Summary By rational modification of electronic and steric properties of pincer ligands, a Co/Fe dual catalyst system is developed for one‐pot sequential Markovnikov alkyne hydrosilylation and stereoselective alkene isomerization. The protocol provides an atom‐economical and efficient approach to trisubstituted ( E )‐alkenyl silanes from widely accessible terminal alkynes with high regio‐ and stereoselectivities under mild conditions. The utility of this reaction was demonstrated by gram‐scale synthesis and derivatization of bioactive molecules. The radical clock and trapping experiments indicated that radical pathway might be operative in the alkene isomerization step.