Regioselective Carbon-Carbon Bond Formation in Titanium Mediated Reaction of Ethylmagnesium Bromide with Allylic Alcohols and Allylic Ethers
31 December 2001 (online)
In the presence of Ti(Oi-Pr)4 reaction of EtMgBr with allylic alcohols and allylic ethers affords the products of formal SN2′ substitution of hydroxy or alkoxy groups with ethyl groups in moderate to good yields and excellent regioselectivity. The mechanism of the reaction includes the formation of titanacyclopropanes as the key organometallic intermediates. Promoting action of EtMgBr on the process of C-C bond formation in the transformation of titanacyclopropane-olefin complex 5 into the titanacyclopentane at complex 6 is proposed.
titanium alkoxides - Grignard reagents - allylic compounds - alkylations - alkenes