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

Participants

Reaction Conditions

Reaction Steps

A 185-ml stainless steel autoclave was charged under argon in a glove box (O2 content<2 ppm) with 1-benzyl-4-(4-chloro-phenyl)-2,5-dihydro-1H-pyrrole-3-carboxylic acid (5.00 g, 15.1 mmol), [Ru(OAc)2((R)-2-Furyl-MeOBIPHEP] (3.8 mg, 5.0 μmol) (S/C 5′000) and methanol (150 mL). The asymmetric hydrogenation was run under 40 bar of hydrogen for 20 h at 30° C. and additional 2 h at 60° C. to complete the conversion (>99.6% conversion and 99.9% ee). After the pressure was released, the white suspension was stirred at 0-5° C. for 2 h, filtered off and the filter cake was washed with cold (0-5° C.) methanol (20 mL) and dried under vacuum at room temperature to yield the title product (4.75 g, 99%) with 99% purity and 99.9% ee. ES-MS m/e: 316.1 (M+H+).

Provenance & Evidence