Copper-catalyzed regio and diastereoselective three component C–N, C–C and C–O bond forming reaction: oxidative sp3 C–H functionalization

Abstract

A highly regio and diastereoselective copper catalyzed three component reaction of tetrahydroisoquinolines (THIQs), aldehydes, and naphthols to furnish naphthoxazine derivatives under mild conditions was developed. The initial generation of iminium ions followed by the nucleophilic attack of naphthol presumed to deliver 15-phenyl-7a,12,13,15-tetrahydronaphtho[1′,2′:5,6][1,3]oxazino[2,3-a]isoquinoline derivatives. The reaction ensured the formation of C–C, C–N and C–O bonds in a one-pot reaction to produce ring fused N,O-acetals in good yields. The three component reaction, the inexpensive copper catalyst in the absence of a co-oxidant/additive and the direct regioselective oxidative sp³ C–H functionalization are the attractive features of this approach. The preliminary photophysical properties obtained for selected compounds were presented.