Enantioselective Synthesis of β-Methyl Amines via Iridium-Catalyzed Asymmetric Hydrogenation of N-Sulfonyl Allyl Amines.

Abstract

The iridium-catalyzed asym. hydrogenation of several N-sulfonyl allyl amines was reported. All substrates could be easily obtained by the Ir-catalyzed isomerization of N-tosylaziridines reported previously. The com. available threonine-derived phosphinite (UbaPHOX) iridium complex had been found to be the best catalyst for this catalytic application, affording β-Me amines I [R1 = H, 4-Cl, 4-Br, etc.;R2 = Me, i-Pr, 4-MeC6H4; R3 = H, Me] with good to excellent ee values (up to 94%). The synthetic potential of this novel methodol. was demonstrated by the formal synthesis of Lorcaserin and LY-404187.