Controllable construction of pharmaceutically significant scaffolds of 2,3-dihydroquinolin-4-one and benzoazepine-5-one via redox-neutral cascade hydride transfer/cyclization

Abstract

The pharmaceutically significant scaffolds of 2,3-dihydroquinolin-4-one and benzoazepine-5-one carrying a privileged 3,3′-spirocyclic oxindole moiety were controllably constructed by relying on cascade condensation/redox-neutral [1,6]/[1,7]-hydride transfer/cyclization in green alcoholic media from 2-aminoacetophenone and diverse aldehydes as well as isatins, which have distinctive features such as (1) controllable access to three diverse product structures carrying a privileged 3,3′-spirocyclic oxindole moiety, (2) transition-metallic catalyst-free conditions, (3) triple functionalization of a methyl ketone with three diverse groups introduced, (4) high step- and atomic-economy and (5) with water as the only by-product etc.