Diethylzinc-Mediated Catalytic Asymmetric Allylation of Benzaldehydes

Significance

The asymmetric allylic alkylation is one of the most valuable tools of enantioselective synthesis. This work is one of the first reports on a highly practical variant of this process: ”Umpolung allylation”, which uses allylic acetates and organometallic reagents like dialkylzinc or trialkylboron as equivalents to allylmetallic species. The authors optimized the catalyst and conditions for the reaction of cyclohexenyl acetate with aryl aldehydes, affording products with high stereoselectivity via a cyclic six-membered transition state.