HCID 178521919, compound → HCID 178431004, compound

Temperature

50 °C

Following general procedure F usin trans‐12a  (67.8 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 1:1.4:1.3 meta:dimeta:para borylation (overall meta:para ratio of 1.8:1) in 98% yield. The crude product was purified by silica gel chromatography (10% EtOAc in Petroleum Ether 40‐60 o C) gave the title compound (as a 1:1.3:1.2 meta:dimeta:para ratio or overall meta:para ratio of 1.9:1, as determined by 1 H NMR) as a white solid (104.3 mg, 0.24 mmol, 94%). The mass quoted above is the actual mass of the isolated mixture of products, whilst the amount of substance in mmol has been calculated by examining the ratios of the dimeta to monoborylated products and accounting for the extra mass due to the higher molecular weight of the dimeta product. By subtracting the resonances for the meta isomer, the NMR data of the dimeta and para isomer can be assigned as follows:

ORD record

ord-a50b47f31a74420f8d51373fe2d335d7

Source dataset

Borylation dataset from Roche

DOI

10.1002/anie.201708967