Carboxylates as Nucleophiles in the Enantioselective Ring‐Opening of Formylcyclopropanes under Iminium Ion Catalysis

Abstract In this work, carboxylic acids, which are typically regarded as poor nucleophiles, are demonstrated to be competent reagents to promote the ring‐opening of formylcyclopropanes after activation of the latter through iminium ion formation. Under optimized reaction conditions, a variety of γ‐acyloxy‐substituted aldehydes can be obtained in high yields and enantioselectivities through the desymmetrization of substituted meso ‐formylcyclopropanes in the presence of a chiral secondary amine as catalyst.