Asymmetric [4 + 2]-Cycloaddition of Copper-Allenylidenes with Hexahydro-1,3,5-triazines: Access to Chiral Tetrahydroquinazolines.

A copper-catalyzed asymmetric formal [4 + 2]-cycloaddition of copper-allenylidenes and hexahydro-1,3,5-triazines has been developed, providing chiral tetrahydroquinazolines in moderate to good yields and with high enantioselectivities for most cases (up to 88% yield and 98% ee).