Synthesis of Disilanes, Dihydrosiloles, and 1,4-Disilacyclohexa-2,5-dienes by Transition-Metal-Free Transfer of Diphenylsilylene and Dimethylsilylene from Silylboronic Esters

We found that the transfer of diphenylsilylene (Ph2Si:) from Ph-2(Et2N)Si-B(pin) (1 a) takes place in toluene or p-xylene at 110-135 degrees C under transition-metal-free conditions. The reaction of alkoxysilanes with 1 a affords alkoxydisilanes through the insertion of diphenylsilylene into the Si-O bond. Dihydrosiloles and a 1,4-disilacyclohexa-2,5-diene are synthesized by the reaction of 1a with 1,3-dienes and an alkyne, respectively, through cycloaddition of the carbon-carbon unsaturated bonds with diphenylsilylene. Me-2(Et2N)Si-B(pin) (10) is applicable to the transition-metal-free transfer of dimethylsilylene (Me2Si:).

Automated summary

A transition-metal-free transfer of diphenylsilylene to Ph-2(Et2N)Si-B(pin) was found, and the reaction can be conducted in toluene or p-xylene.