HCID 178463682, compound → HCID 178463663, compound

Participants

Reaction Conditions

Reaction Steps

Following general procedure F using N‐ethyl‐2,2,2‐trifluoro‐N‐(2‐(trifluoromethyl)benzyl)acetamide (13) (149.5 mg, 0.50 mmol), B2pin2 (254 mg, 1.0 mmol), [Ir(COD)OMe]2 (5.0 mg, 0.0075 mmol) and 1a (7.6 mg, 0.015 mmol) in THF (2.5 mL). The reaction was stirred at rt °C for 20 hours before cooling and the solventsremoved. Analysis of crude 1 H NMR using internalstandard 1,2‐dimethoxyethane showed 2.4:1 meta:para borylation in 98% yield as a mixture of rotamers. The crude product was purified by silica gel chromatography (Pet. Ether (40‐60):EtOAc (19:1‐9:1) to give the title compound (as a 1.5:1:0.8 mixture of meta:para:B2pin2 ratio, as determined by 1 H NMR) as a colourless oil (180 mg). As the B2Pin2 impurity was found to be inseparable from the final product on silica, corrected yield is calculated as 0.36 mmol, 71%.  This sample required heating to 120 o C in DMSO for the rotamers to coalesce. However, it was subsequently then possible to deconvolute meta:para ratio in the rt CDCl3 spectrum.

Provenance & Evidence