Divergent synthesis of nitrogen heterocycles via H₂O-mediated hydride transfer reactions

The H₂O-promoted controllable synthesis of diverse nitrogen heterocycles from readily available feedstocks was developed by a hydride transfer strategy. A variety of 3-carboxyl and 3-acyl substituted tetrahydroquinolines and 3,4-dihydroquinolin-2(1H)-ones were obtained via cascade Knoevenagel condensation/[1,5]-hydride transfer/cyclization/hydrolysis/decarboxylation and cascade Knoevenagel condensation/[1,5]-hydride transfer/N-dealkylation/N-acylation processes, respectively. In addition, the synthetic utility of the methodology and mechanistic studies were also well presented.