Asymmetric palladium-catalyzed allylic alkylation using dialkylzinc reagents: a remarkable ligand effect

Angew Chem Int Ed Engl. 2014 Jul 1;53(27):7068-73. doi: 10.1002/anie.201309074. Epub 2014 May 28.

Abstract

A serendipitously discovered palladium-catalyzed asymmetric allylic alkylation reaction with diorganozinc reagents, which displays broad functional group compatibility, is reported. This novel transformation hinges on a remarkable ligand effect which overrides the standard "umpolung" reactivity of allyl-palladium intermediates in the presence of dialkylzincs. Owing to its mild conditions, enantioselective allylic alkylations of racemic allylic electrophiles are possible in the presence of sensitive functional groups.

Keywords: alkylation; deracemization; diethylzinc; enantioselectivity; palladium.