Chiral Binaphthyl Box-Copper-Catalyzed Enantioselective Tandem Michael-Ketalization Annulations for Optically Active Aryl and Heteroaryl Fused Bicyclicnonanes.

The combination of chiral binaphthyl box-copper(II) with triflimide (Tf2NH) was identified as an efficient catalytic system for the asymmetric Michael/ketalization of (E)-2-hydroxyaryl-2-oxobut-3-enoates or (E)-ethyl 4-(2-aminoaryl)-2-oxobut-3-enoates with pyrazolone derivatives. The corresponding asymmetric tandem reactions provided a series of enantioenriched aryl and heteroaryl fused 2,8-O,O- or O,N-bicyclo[3.3.1]nonanes in high yields with excellent enantio- and diastereoselectivities.