Metal-free Bronsted acid catalyzed transfer hydrogenation: enantioselective synthesis of tetrahydroquinolines.

Abstract

Diphenylphosphate catalyzes the metal-free redn. of ketimines under hydrogen-transfer conditions with Hantzsch dihydropyridine as the hydrogen source. The asym. variant of this procedure using 1 mol % of a chiral BINOL-phosphate I as catalyst is reported. [on SciFinder(R)]