Diphenylsilylene Transfer to Unsymmetrical 1,3-Dienes: Synthesis of 2,3-Dihydrosiloles through Carbon Skeletal Reorganization

The silylene transfer to 1,3-dienes with carbon skeletal reorganization is a powerful method for construction of silacarbocycles. However, the reaction of unsymmetrical 1,3-dienes posed the challenge of producing a mixture of two structural isomers. Herein, we demonstrate the diphenylsilylene transfer from Ph 2 (Et 2 N)Si–B(pin) to styrylcycloalkenes. This reaction selectively afforded one isomer of the possible 2,3-dihydrosiloles. We also report on a palladium-catalyzed 1,3-diene-silylene (4 + 1) cycloaddition to afford 2,5-dihydrosiloles from the identical starting materials.