Copper-catalyzed asymmetric dearomative alkynylation of isoquinolines

Abstract

Cu/(Ph-pybox)-catalyzed asymmetric dearomative alkynylation of isoquinolines has been realized in high to excellent enantioselectivities (up to 96% ee) with α-bromoacetophenone as an activator and 1,1′-binaphthyl-2,2′-diyl hydrogenphosphate as an additive. This novel reaction tolerates a wide variety of functional groups and affords enantioenriched C1-alkynyl 1,2-dihydroisoquinolines in high yields and ee under mild conditions.