InBr3 catalyzed three-component reactions of an aryldiazoacetate, an alcohol, and a carbonyl compound

InBr3 promoted three-component reactions of an aryldiazoacetate, an alcohol, and an electron deficient carbonyl compound gave α,β-dihydroxyl acid derivatives in good yield with high diastereoselectivity. The reaction is proposed through a protic oxonium ylide trapping process. The reaction mechanism for the formation of the protic oxonium ylide via Lewis acid InBr3 catalyzed diazo decomposition is suggested through a vinyl cationic intermediate.