Triphenylphosphine → 1-tert-butyl 2-[2-(trimethylsilyl)ethyl] (2S,4R)-4-[(2-phenyl-6-vinylquinolin-4-yl)oxy]pyrrolidine-1,2-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-tert-butyl 2-[2-(trimethylsilyl)ethyl] (2S,4S)-4-hydroxypyrrolidine-1,2-dicarboxylate 3 (1.0 g, 3.02 mmol) in THF (30 mL) was added 2-phenyl-6-vinylquinolin-4(1H)-one 2 (0.78 g, 3.17 mmol) and PPh3 (1.19 g, 4.52 mmol). The flask was then cooled to 0° C. and diethylazodicarboxylate (0.713 mL, 4.52 mmol) was added slowly. The mixture was then warmed to RT and stirred overnight (16 h). At this time, the starting material to product ratio was 2:1. The reaction was re-cooled to 0° C., and additional PPh3 (1.19 g, 4.52 mmol) and diethylazodicarboxylate (0.713 mL, 4.52 mmol) were added. After stirring for an additional 19 h, only a small amount of starting material remained. Silica gel was then added to the reaction and the mixture was filtered through silica gel with EtOAc as the eluent. The crude mixture was then purified on silica (5-40% EtOAc/hexanes) to yield 0.85 g (50% yield) of 1-tert-butyl 2-[2-(trimethylsilyl)ethyl] (2S,4R)-4-[(2-phenyl-6-vinylquinolin-4-yl)oxy]pyrrolidine-1,2-dicarboxylate 5. 1H NMR (500 MHz, CDCl3) ppm: mixture of amide rotamers: 8.43 (m, 1H), 8.13-8.09 (m, 2H), 7.92 and 7.91 (2 br s, 2H), 7.56 (m, 3H), 7.12 and 7.11 (2 br s, 1H), 6.92 (br dd, J=17.5 Hz, 10.5 Hz, 1H), 6.02 (d, J=17.5 Hz, 1H), 5.58 (d, J=10.5 Hz, 1H), 5.53 and 5.49 (2 br s, 1H), 4.64 and 4.54 (2 app t, J=7.5 Hz, 1H), 4.27 (app t, J=7 Hz, 2H), 4.07 (m, 1.5H), 3.89 (br d, J=13 Hz, 0.5H), 2.81 (m, 1H), 2.55 (m, 1H), 1.47 and 1.45 (2 s, 9H), 1.04 (m, 2H), 0.07 and 0.06 (2 s, 9H). LRMS (CI, [M+H]) Calc'd=561.4. found=561.4. HRMS (APCI, [M+H]+) Calc'd for C32H41N2O5Si: 561.2779. found: 561.2749.

Provenance & Evidence