Efficient organocatalytic asymmetric synthesis of 2-amino-4H-chromene-3-carbonitrile derivatives

The organocatalytic enantioselective tandem Michael addition-cyclization of malononitrile to nitroalkenes for the direct synthesis of chiral 2-amino-4H-chromene-3-carbonitrile derivatives was investigated. Good yields and enantioselectivities (up to 91% ee) were achieved. This organocatalytic asymmetric tandem Michael addition-cyclization provides an efficient route toward the synthesis of optically active functionalized chromenes. (C) 2012 Elsevier Ltd. All rights reserved.