Water → HCID 178474735, compound

Participants

Reaction Steps

After stirring for 30 min, a solution of cis-tert-butyl 3-(2-acetamido-1-(tert-butylamino)-1-oxohex-5-en-2-yl)cyclobutyl(benzyl)carbamate (5.34 g, 10.5 mmol), chloro-1,5-cyclooctadiene iridium(I) dimer (212 mg, 0.32 mmol, 3 mol %) and 1,2-bis(diphenylphosphino)ethane (252 mg, 0.63 mmol, 6 mol %) in dichloromethane (50 mL) was cooled to 0° C. and carefully treated with 4,4,5,5-tetramethyl-[1,3,2]dioxaborolane (3.1 mL, 21.1 mmol, 2 eq) over 5 min. After slowly warming to room temperature and stirring overnight, the reaction was poured into water and extracted with ethyl acetate (3×). The combined organic phase was washed with saturated aqueous sodium chloride, dried over anhydrous magnesium sulfate, filtered and concentrated. Purification by flash column chromatography (silica gel, 10-40% ethyl acetate in heptane) gave cis-tert-butyl 3-(2-acetamido-1-(tert-butylamino)-1-oxo-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexan-2-yl)cyclobutyl(benzyl)carbamate (4.8 g, 7.83 mmol, 74%). ESI MS found for C34H56BN3O6 m/z [614.2 (M+1), 636.2 (M+23)].

Provenance & Evidence