Ethyldiphenylphosphine → tert-butyl 4-(tert-butylcarbamoyl)-4-(N-methylacetamido)-8-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)octylcarbamate

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Reaction Steps

While under an atmosphere of argon, a solution of bis(1,5-dicyclooctadiene)diiridium(I)dichloride (6 mg; 0.009 mmol) and diphenylphosphinoethane (7 mg, 0.018 mmol) in dichloromethane (1 mL) was cooled to 0° C. and treated with 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.174 mL, 1.2 mmol). After stirring for 30 min, a solution of tert-butyl 4-(tert-butylcarbamoyl)-4-(N-methylacetamido)oct-7-enylcarbamate (120 mg, 0.3 mmol) in dichloromethane (4 mL) was added and the solution was stirred an additional 16 h. Dichloromethane (10 mL) was added, and the solution was washed successively with water and sat'd aq sodium chloride, dried over MgSO4, filtered and concentrated. Purification by column chromatography (3% methanol in dichloromethane) gave tert-butyl 4-(tert-butylcarbamoyl)-4-(N-methylacetamido)-8-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)octylcarbamate (142 mg, 90%). ESI MS found for C27H52BN3O6 m/z [548.7 (M+Na+), 526.7 (M+1), 570.8 (M+HCOO−), 524.6 (M−1)].

Provenance & Evidence