Radical Hydrometalation of Functional Ethylenic Compounds: Radical Autoinhibition Changes the Regioselectivity
摘要:
Hydrometalation of carbon-carbon double bonds by group 14 hydrides is inhibited by carbonyl compounds-mainly by alpha,beta-unsaturated carbonyl groups-as efficiently as by classical radical trapping compounds, such as galvinoxyl and hydroquinone. This phenomenon, in the case of polyfunctional C=C- and C=O-containing compounds, such as carvone, leads to an autoinhibition of the exocyclic alkenylic hydrometalation under normal reaction conditions, while under drastic conditions, the O-metalation of the alpha,beta-unsaturated carbonyl group occurs.