Oxygen → (3S,4S)-1-Benzyl-4-(3,4-dichloro-phenyl)-pyrrolidine-3-carboxylic acid

Participants

Reaction Steps

A 185-ml stainless steel autoclave was charged under argon in a glove box (O2 content≦2 ppm) with 1-benzyl-4-(3,4-dichloro-phenyl)-2,5-dihydro-1H-pyrrole-3-carboxylic acid (1.00 g, 2.87 mmol), [Ru(OAc)2((R)-TMBTP)] (1.16 mg, 1.44×10−6 mol, S/C 2′,000) and methanol (30 ml). The asymmetric hydrogenation was run for 20 h at 30° C. under 40 bar of hydrogen (18.5% conversion). After the pressure was released, the off-white suspension was evaporated to dryness to yield 0.98 g (12%) of crude (S,S)-Ib with 12.1% purity and 94.5% ee.

Provenance & Evidence