O=O.[CH2:3]([N:10]1[CH2:14][C:13]([C:15]2[CH:20]=[CH:19][C:18]([Cl:21])=[CH:17][CH:16]=2)=[C:12]([C:22]([OH:24])=[O:23])[CH2:11]1)[C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1.[H][H]>CO>[CH2:3]([N:10]1[CH2:14][C@H:13]([C:15]2[CH:16]=[CH:17][C:18]([Cl:21])=[CH:19][CH:20]=2)[C@H:12]([C:22]([OH:24])=[O:23])[CH2:11]1)[C:4]1[CH:5]=[CH:6][CH:7]=[CH:8][CH:9]=1A 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+).
Wird geladen…
