Enantioselective Michael Addition of Dimethyl Malonate to (E)-beta-Nitrostyrenes Catalyzed by Cinchona Alkaloids Under Solvent-Free Condition

摘要

Under solvent-free condition the addition of dimethyl malonate ( 1) to (E)-beta-nitrostyrenes 2a-j proceeds smoothly in the presence of 2.5 mol% of 6'-hydroxy cinchonine (QD-OH) and equimolar amounts of reagents at 30 C. The corresponding products 3a-j are obtained with satisfactory enantiomeric excesses (68-88%) and high yields (70-92%).