Rh2(II)-catalyzed cyclization/gem-hydrosilylation of benzene-fused 1,6-enynones

Abstract

Cyclization/hydrosilylation of 1,6-enynes represents a highly efficient and atom-economical strategy for constructing silyl-functionalized five-membered carbocyclic or heterocyclic structural units from simple acyclic subunits containing ene and yne fragments. In contrast to hydrosilylation at distinct unsaturated bonds of the enyne substrate, the addition of hydrogen and silicon to the same position (geminal addition) during cyclization remains underexplored. Herein, we report a dirhodium(II)-catalyzed cyclization/geminal hydrosilylation of 1,6-enynes that accommodates primary, secondary and tertiary silanes. This protocol not only enables the facile one-step synthesis of bicyclo[3.1.0]hexanone silanes but also provides access to novel naphthol-derived silanes. Notably, this work achieves an asymmetric variant of cyclization/geminal hydrosilylation for 1,6-enynes, expanding the synthetic utility of this transformation.