(S)-tert-butyl 1-(allyl(phenyl)amino)-1-oxopent-4-en-2-ylcarbamate → (S,Z)-tert-butyl 2-oxo-1-phenyl-2,3,4,7-tetrahydro-1H-azepin-3-ylcarbamate

Participants

Reaction Conditions

Reaction Steps

A solution of (S)-tert-butyl 1-(allyl(phenyl)amino)-1-oxopent-4-en-2-ylcarbamate (0.98 g, 2.97 mmol) in ClCH2CH2Cl (400 mL) was degassed with argon for 5 min. Then, Grubbs II catalyst (0.126 g, 0.148 mmol) was added. The reaction was stirred at 60° C. under argon for 16 hr. The reaction mixture was cooled to rt and concentrated to dryness. The brownish residue was purified using silica gel chromatography (ISCO system) eluting with a gradient of 0-30% EtOAc/Hex to give (S,Z)-tert-butyl 2-oxo-1-phenyl-2,3,4,7-tetrahydro-1H-azepin-3-ylcarbamate (0.787 g, 2.60 mmol, 88% yield) as a white solid. 1H NMR (400 MHz, CDCl3) δ ppm 7.42-7.34 (m, 2H), 7.30-7.24 (m, 1H), 7.24-7.19 (m, 2H), 6.06-5.66 (m, 2H), 5.23-5.10 (m, 1H), 4.79 (dd, J=21.1, 17.3 Hz, 1H), 3.85-3.71 (m, 1H), 2.85-2.70 (m, 1H), 2.43-2.29 (m, 1H), 1.55-1.43 (m, 10H).

Provenance & Evidence