Primary amine/(+)-CSA salt-promoted organocatalytic conjugate addition of nitro esters to enones

Abstract

The combination of 9-amino-9-deoxy-epi-cinchonine and (+)-CSA resulted in a novel primary amine-based organocatalyst for effective iminium activation of α,β-unsaturated ketones. Such a catalytic system could catalyze the conjugate addition of nitroacetate to enones in a highly enantioselective manner, affording the desired adducts in high yields and with up to 99% ee. © 2010 American Chemical Society.