A Highly cis‐Selective and Enantioselective Metal‐Free Hydrogenation of 2,3‐Disubstituted Quinoxalines

Abstract A wide range of 2,3‐disubstituted quinoxalines have been successfully hydrogenated with H 2 using borane catalysts to produce the desired tetrahydroquinoxalines in 80–99 % yields with excellent cis selectivity. Significantly, the asymmetric reaction employing chiral borane catalysts generated by the in situ hydroboration of chiral dienes with HB(C 6 F 5 ) 2 under mild reaction conditions has also been achieved with up to 96 % ee , and represents the first catalytic asymmetric system to furnish optically active cis ‐2,3‐disubstituted 1,2,3,4‐tetrahydroquinoxalines.