Reaction Steps
Me3SiOTf (0.90 ml, 5.0 mmol ) was added at −78° C. to a solution of iminiun bromide 3f (1.83 g, 5.0 mmol) in CH2Cl2 (30 ml). The suspension was warmed to room temperature and stirred for 1 hour. After evaporation of the solvent, a solid residue was obtained. Then to a 1/1 mixture of LDA and iminium triflate (5.0 mmol), 30 ml of THF was added at −78° C. The suspension was warmed to room temperature and stirred for 30 min. After evaporation of the solvent under vacuum, a solid residue containing carbene Cf and LiOTf was obtained. 1H NMR (thf-d8, 25° C.): 7.00-7.20 (m, 3H, Har), 3.34 (m, 1H, CHCH3), 2.85 (sept, 2H, CHCH3, J=6.9), 1.85-1.96 (m, 1H, CH2), 1.29-1.62 (m, 3H, CH2), 1.18 (d, 3H, CHCH3, J=6.9), 1.14 (d, 3H, CHCH3, J=6.9), 1.11 (s, 3H, CH3), 1.04 (s, 3H, CH3), 1.00 (d, 3H, CHCH3, J=6.6), 0.98 (d, 3H, CHCH3, J=6.3), 0.94 (d, 3H, CHCH3, J=6.3). 13C NMR (thf-d8, 25° C.): 322.00 (C), 144.45 (Car), 144.02 (Car), 142.35 (Car), 126.86 (Car), 123.44 (Car), 123.37 (Car), 56.15 (CH), 41.88 (C), 28.39, 28.26, 27.95, 27.12 (CH2), 26.88 (CH2), 26.47, 24.64, 23.91, 22.21, 21.70, 18.34.
