A highly chemo- and enantioselectiveorganocatalyticcyclopropanation of α,β-unsaturated aldehydes with bromomalonate and 2-bromoacetoacetate esters is presented. The reaction is catalyzed by chiral amines and gives access to 2-formylcyclopropanes in high yields and up to 99 % ee.
Enantioselective oxidative domino reactions of allylic alcohols to functionalized aldehydes have been developed. The one pot domino oxidation-iminium activation represents a convenient strategy for the enantioselective addition of malonates to allylic alcohols and the asymmetric formation of formyl cyclopropanes.