Tetrahydrofuran → HCID 66833675, compound

Participants

Reaction Steps

In a 50 mL round bottomed flask, a solution of bis(1,5-cyclooctadiene)diiridium(I) dichloride (72 mg, 0.11 mmol) and 1,2-bis(diphenylphosphino)-ethane (84 mg, 0.21 mmol) in tetrahydrofuran (10 mL, 100 mmol) was cooled to 0° C., stirred for 15 min and treated with 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (450 uL, 3.1 mmol). After additional stirring for 5 min the cooling bath was removed and the reaction mixture was allowed to warm to room temperature with stirring a period of 15 min. The reaction mixture was then recooled to 0° C. and treated with a solution of 2-acetamido-N-tert-butyl-2-((R)-1-(2-nitrophenylsulfonyl)pyrrolidin-3-yl)hex-5-enamide (1.00 g, 2.08 mmol) in tetrahydrofuran (2 mL, 20 mmol) added in a dropwise manner via syringe. After stirring for 5 min at 0° C. the reaction was warmed to room temperature and stirred until the desired product was obtained in good yield. The reaction mixture was quenched by pouring the crude into a saturated solution of aqueous sodium carbonate (50 mL). The aqueous layer was extracted using ethyl acetate (3×30 mL), and the combined organic layers were washed with saturated aqueous sodium chloride (20 mL), dried over Na2SO4, filtered and concentrated to give 2-acetamido-N-tert-butyl-2-((R)-1-(2-nitrophenylsulfonyl)pyrrolidin-3-yl)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanamide (1.20 g, 94.8%) as a foam. The titled compound was used without further purification. ESI MS found for C28H45N4O8BS m/z 609.5 (M+H)+; 607.5 (M−H)−.

Provenance & Evidence