HCID 1517066, compound → HCID 178431046, compound

Participants

Reaction Conditions

Reaction Steps

Following general procedure F using 4h (62.9 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 1:0.15:1.8 meta:dimeta:para borylation in 93% yield (these numbers include the meta/para products which have 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 and reprotonation of the NH‐borylation products and gave the title compound (as a 1:0.14:1.9 mixture of meta:dimeta:para ratio, as determined by 1 H NMR) as a colourless oil (100 mg). A small amount of B2Pin2 impurity wasfound to be inseparable from the final product on silica. Corrected yield ‐ 92 mg, 0.23 mmol, 92%.  By subtracting the resonances for the meta isomer, the NMR data of the para isomer can be assigned as follows:

Provenance & Evidence