Abstract
The first organocatalytic asymmetric synthesis of 4H-chromenes bearing a trifluoromethylated tetrasubstituted carbon center is presented. Chiral secondary amines promote the oxa-Michaelaldol cascade reaction between alkynals and 2-trifluoroacetylphenols via iminium-allenamine activation to produce pharmaceutically important heterocycles with excellent enantioselectivities. The proposed reaction can be scaled-up easily with maintenance of the excellent enantioselectivity.