Oxaziridine-mediated enantioselective aminohydroxylation of styrenes catalyzed by copper(II) bis(oxazoline) complexes

Abstract

We report an oxaziridine-mediated enantioselective aminohydroxylation of olefins catalyzed by a chiral copper(II) bis(oxazoline) complex. A variety of styrenic olefins undergo efficient aminohydroxylation with excellent regioselectivity and synthetically useful levels of enantioselectivity (up to 84% ee). The reaction can be conducted on multi-gram scale with as little as 2 mol % of the copper(II) catalyst. Hydrolysis of the resulting 1,3-oxazolines under acidic conditions produces N-sulfonyl amino alcohols that can be purified by recrystallization to afford very high levels of enantioselectivity.