Water → 2-acetamido-N-tert-butyl-2-(4-(4-chlorophenyl)cyclohexyl)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanamide

関与物質

反応手順

A solution of 2-acetylamino-2-[4-(4-chlorophenyl)-cyclohexyl]hex-5-enoic acid tert-butylamide (940 mg, 2.25 mmol) in dichloromethane (9 mL) was treated with chloro-1,5-cyclooctadiene iridium(I) dimer (45 mg, 3 mol %) and 1,2-bis(diphenylphosphino)ethane (54 mg, 6 mol %). After stirring for 30 minutes, 4,4,5,5-tetramethyl-[1,3,2]dioxaborolane (576 mg, 0.65 mL, 4.5 mmol) was added dropwise and the stirring was continued 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 in vacuo. Purification by flash column chromatography (silica gel, 10-40% ethyl acetate in heptane) gave 2-acetamido-N-tert-butyl-2-(4-(4-chlorophenyl)cyclohexyl)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)hexanamide as a colorless oil (985 mg, 80%); 1H NMR (CDCl3, 300 MHz) δ 7.25 (d, J=7.5 Hz, 2H), 7.08 (d, J=7.5 Hz, 2H), 6.99 (br s, NH, 1H), 5.52 (br s, NH, 1H), 2.84 (td, J1=13 Hz, J2=3.0 Hz, 1H), 2.37 (t, J=12 Hz, 1H), 2.24 (t, J=12 Hz, 1H), 2.00 (s, 3H), 1.90 (m, 4H), 1.20-1.48 (m, 7H), 1.38 (s, 9H), 1.22 (s, 12H), 1.06 (m, 2H) and 0.75 (t, J=7.5 Hz, 2H); MS (+CI): m/z for C30H48BClN2O4: expected 546.3. found 547.3 (M+H)+, 569.3 (M+Na)+.

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