1,2-Bis(diphenylphosphino)ethane → Ethyl cis-1-benzyl-4-(1-tert-butoxycarbonylaminocyclopropyl)pyrrolidine-3-carboxylate

Participants

Reaction Steps

Under a nitrogen gas stream, bis(bicyclo[2.2.1]hepta-2,5-diene)rhodium (I) perchlorate (54.5 mg, 0.14 mmol) and 1,2-bis(diphenylphosphino)ethane (67.4 mg, 0.17 mmol) were dissolved in degassed methanol (25 ml) and stirred at room temperature for 10 minutes. To this catalyst solution was added a solution of ethyl 1-benzyl-4-(1-tert-butoxycarbonylaminocyclopropyl)-3-pyrroline-3-carboxylate (1.090 g, 2.820 mmol) in dry and degassed methanol (15 ml). The thus obtained liquid reaction mixture was then stirred under a hydrogen atmosphere (1 kg/cm2) at room temperature for 2.5 hours. After adding active carbon (1 g), the liquid reaction mixture was allowed to stand at room temperature for 30 minutes and then filtered-through celite (washed with methanol). The filtrate was concentrated under reduced pressure and the residue was subjected to flash silica gel column chromatography (eluent:n-hexane:ethyl acetate=5:1) to obtain 1.071 g (97.8%) of the title compound as colorless crystals.

Provenance & Evidence