反应详情

温度

50 °C

Following general procedure F using 4g (68.8 mg, 0.25 mmol), B2pin2 (127 mg, 0.50 mmol), [Ir(COD)OMe]2 (2.5 mg, 0.00375 mmol) and dtbpy (2.0 mg, 0.0075 mmol) in THF (1.25 mL). Stirred in vial at 50 °C for 20 hours. Analysis of crude 1 H NMR using internal standard 1,2‐dimethoxyethane showed 2.4:1 meta:para borylation in 82% yield (these numbers include samll amounts of the meta/para products which had also undergone NH borylation). The crude product was purified by silica gel chromatography (15% EtOAc in Petroleum Ether 40‐60 o C) which resulted in the cleavage of the N‐B bond in the NH‐borylation products and gave the title compound (as a 2.5:1 mixture of meta:para ratio, as determined by 1 H NMR) as an off‐white solid (61 mg, 0.15 mmol, 61%). By subtracting the resonances for the meta isomer, the NMR data of the para isomer can be assigned as follows: