2,2,2-Trifluoroethyl trifluoromethanesulfonate → tert-Butyl ((5S,6R)-6-methyl-2-oxo-5-(o-tolyl)-1-(2,2,2-trifluoroethyl)piperidin-3-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

To a solution of 37 (50 g, 0.164 mol) and DMPU (25 g, 0.2 mol) in THF (500 mL) was added tert-BuOLi (16.5 g, 0.2 mol) in portions at 20° C. for 0.5 h. After the mixture was degassed for 30 min at 20° C., CF3CH2OTf (45.8 g, 0.2 mol) was added at 20-25° C. The reaction was stirred for 24 h at 20-25° C. After the reaction was complete, the mixture was quenched by water, and then partitioned with water and EtOAc. The organic solution was dried over Na2SO4 and concentrated. The crude residual was further purified by flash chromatography on silica gel (2-10% EtOAc/PE) to give product 38 (50 g, 78% yield). 1H NMR (DMSO-d6, 400 MHz): δ 7.18-7.13 (m, 4H), 4.17 (m, 1H), 4.11 (br, 1H), 3.67 (m, 3H), 2.66 (s, 1H), 2.33 (d, 3H), 1.83 (t, 1H), 1.41 (s, 9H), 0.96 (d, 3H); MS (ESI) m/e [M+H]+ 405.17.

Provenance & Evidence