Asymmetric Synthesis of Tetrahydroquinolines via Saegusa-type Oxidative Enamine Catalysis/1,5-Hydride Transfer/Cyclization Sequences

Enantioselective organocatalytic synthesis of tetrahydroquinolines has been achieved via Saegusa‐type oxidative enamine catalysis/1,5‐hydride transfer/cyclization sequences. The feature of this research is a one‐pot transformation of 3‐aryl aldehydes into tetrahydroquinolines by using environmentally benign catalytic Saegusa oxidation and highly efficient internal redox reactions. The synthetically useful ring‐fused tetrahydroquinoline derivatives were obtained in moderate yields and high levels of enantioselectivity. Enamine catalysis you Sae? The organocatalytic Saegusa‐type oxidative enamine catalysis/1,5‐hydride transfer/ring closure reaction is described. This neutral reaction cascade allows for the efficient formation of ring‐fused tetrahydroquinolines in high enantioselectivity. DNBS=2,4‐dinitrobenzensulfonic acid; TMS=trimethylsilyl.