A Sc(OTf)3-catalyzed cascade reaction of o-aminoacetophenone with methanamine: construction of dibenzo[b,h][1,6]naphthyridine derivatives

Abstract

An unexpected Sc(OTf)₃-catalyzed and air-mediated cascade reaction of o-aminoacetophenones with methanamines was discovered as an efficient synthetic approach to a novel class of fluorescent fused-four-ring dibenzo[b,h][1,6]naphthyridine derivatives. Two possible mechanisms of the reaction were proposed. The photophysical properties of the dibenzo[b,h][1,6]naphthyridine 1a were initially considered.