Reaction Steps
To a solution of 8-diphenylphosphino-2-methyl-1,2-dihydroquinoline (2) (10.5 g, 32 mmol) in CH2Cl2 (100 mL) was added H2O2 (6.6 mL, 30% w/w in H2O, 63.9 mmol) at 0° C. and the solution was stirred at room temperature for 1 hour. The solution was then cooled to 0° C., saturated aqueous Na2SO3 solution (10 mL) was added and the mixture was warmed to room temperature. Products were extracted with EtOAc, washed with water and saturated aqueous NaCl, dried (MgSO4) and evaporated to give 5 as a yellow oil (11 g, quantitative). 1H NMR (400.13 MHz, CDCl3) δ 7.7-7.6 (m, 4H, Ph-H), 7.6-7.5 (m, 2H, Ph-H), 7.5-7.4 (m, 4H, Ph-H), 6.97 (bs, 1H, N1—H), 6.87 (d, 1H, J=7.2 Hz, C5—H), 6.55 (ddd, 1H, J=14.0, 8.0, 1.6 Hz, C7—H), 6.36 (ddd, 1H, J=10.0, 7.6, 2.8 Hz, C6—H), 6.22 (d, 1H, J=10.0 Hz, C4—H), 5.51 (ddd, 1H, J=10.0, 4.0, 2.0 Hz, C3—H), 4.43 (m, 1H, C2—H), 1.17 (d, 3H, J=6.8 Hz, C1′—CH3) ppm; 13C NMR (100.61 MHz, CDCl3) δ 148.2 (d, J=5.1 Hz), 146.0 (d, J=6.1 Hz), 135.7 (d, J=8.1 Hz), 134.8, 132.4, 131.3 (d, J=5.1 Hz), 131.0 (d, J=11.1 Hz), 130.8 (d, J=10.1 Hz), 130.7 (d, J=10.1 Hz), 130.1, 129.2, 127.2 (d, J=12.1 Hz), 126.6 (d, J=13.1 Hz), 126.3, 125.0 (d, J=8.1 Hz), 124.1 (d, J=13.1 Hz), 122.8, 121.1, 119.7 (d, J=8.1 Hz), 113.6 (d, J=14.1 Hz), 107.3, 106.2, 46.9, 23.5 ppm; 31P NMR (161.97 MHz, CDCl3) δ 36.0 ppm.
