4,4,5,5-Tetramethyl[1,3,2]dioxaborolane → (E)-N,N-dimethyl-1-(4-(2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)vinyl)phenyl)methanamine

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Reaction Conditions

Reaction Steps

4,4,5,5-Tetramethyl-1,3,2-dioxaborolane (1.20 mL, 8.23 mmol) was added to an argon-purged solution of 1-(4-ethynylphenyl)-N,N-dimethylmethanamine (262 mg, 1.65 mmol) and HRuCl(CO)(PPh3)3 (104.1 mg, 0.11 mmol) in toluene (9.0 mL). The resulting mixture was heated at 50° C. for 12 h. The product was extracted into Et2O (250 mL), and the organic layer was washed sequentially with water (3×20 mL) and brine (20 mL), dried (Na2SO4) and evaporated in vacuo. Purification by column chromatography (silica gel, 50-100% CH2Cl2 in Et2O) gave (E)-N,N-dimethyl-1-(4-(2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)vinyl)phenyl)methanamine (402 mg, containing 20% pinacol impurity by 1H NMR, 68% yield). 1H NMR (400 MHz, CDCl3) δ 7.46 (d, J=8 Hz, 2H), 7.4 (d, 1H), 7.28 (d, 2H), 6.16 (d, 1H), 3.42 (s, 2H), 2.24 (s, 6H), 1.32 (s, 12H); MS ESI 288.0 [M+H]+, calcd for [C17H26BNO2+H]+ 288.2.

Provenance & Evidence