Reaction Steps
In a dry round bottom flask under argon, an ice-cold solution of dimethylaminoferrocene 11 (229 mg, 1.00 mmol) in THF (10 mL) was treated with BF3.OEt2 (0.13 mL, 1.05 mmol). After 15 min, the yellow solution was cooled to −40° C. and n-BuLi (0.46 mL of 2.40 M solution in hexanes, 1.10 mmol) was added by syringe to give an orange-red solution that was stirred for 1 h before ClPCy2 (0.24 mL, 1.10 mmol) was added and the mixture was allowed to warm to room temperature. The reaction mixture was diluted with Et2O (10 mL) and worked up with saturated aqueous NaHCO3 solution (10 mL). The organic layer was washed with H2O (1×10 mL), brine (1×10 mL), dried over anhydrous Na2SO4 and concentrated to dryness. The residue was redissolved in pentane and chromatographed on silica gel (25 mL), eluting with 95:5 pentane/Et2O to give 397 mg (77%) of the desired aminophosphine 12j as a moderately air-sensitive viscous orange oil. Rf (SiO2, 9:1 hex/EtOAc) 0.50; IR (CHCl3): vmax 2920, 2848, 1489, 1446 cm−1, 31P NMR (121 MHz, acetone-d6): δ −12.3; 1H NMR (300 MHz, acetone-d6): δ 4.22 (s, 5H), 4.15 (t, 1H, J=1.1 Hz), 4.04 (t, 1H, J=2.3 Hz), 3.92 (t, 1H, J=1.7 Hz), 2.75 (s, 6H), 2.49-2.41 (m, 1H), 2.00-1.93 (m, 1H), 1.92-1.81 (m, 3H), 1.77-1.67 (m, 2H), 1.67-1.61 (m, 1H), 1.61-1.52 (m, 3H), 1.50-1.20 (m, 7H), 1.20-1.06 (m, 2H), 1.06-0.97 (m, 1H), 0.90-0.79 (m, 1H); 13C NMR (75.5 MHz, acetone-d6) δ 118.0 (d, J13C-31P=14.0 Hz), 67.5, 66.6 (d, J13C31P=3.4 Hz), 63.3 (d, J13C-31P=25.3 Hz), 63.2, 61.3 (d, J13C-31P=1.5 Hz), 43.9 (d, J13C-31P=13.2 Hz), 35.0 (d, J13C-31P=15.9 Hz), 33.2 (d, J13C-31P=13.2 Hz), 32.2 (d, J13C-31P=20.6 Hz), 30.2 (d, J13C-31P=15.9 Hz), 29.5 (d, J13C-31P=10.8 Hz), 29.0, 27.3 (d, J13C-31P=11.8 Hz), 27.2 (d, J13C-31P=6.5 Hz), 27.0 (d, J13C-31P=12.8 Hz), 26.8 (d, J13C-31P=8.3 Hz), 26.3 (d, J13C-31P=15.5 Hz). EIMS (m/z (%)): 425 (M+, 87), 130 (62), 55 (100), 41 (94); HRMS (EI; m/z): calcd for C24H36NP56Fe 425.1936. Found 425.1934.
