Tris(1,1-dimethylethyl)phosphine → HCID 59004667, compound

Participants

Reaction Steps

Compound 80 (265 mg, 0.904 mmol), Tris(dibenzylideneacetone) dipalladium (0) (82.7 mg, 0.0904 mmol) and anhydrous tetrahydrofuran (20 mL) were charged to a dry argon purged flask fitted with magnetic stir bar and condenser. A solution of tri-tert-butylphosphine (10 wt % in hexane, 365.7 mg, 538 ul, 0.1808 mmol) is added followed by dropwise addition of a 1 M tetrahydrofuran solution of lithium bis(trimethylsilyl)amide (2.71 ml, 2.710 mmol) and mixture refluxed for a period of 45 minutes. The mixture was cooled to room temperature then to 0° C., quenched with 1M HCl (10 mL) and stirred for 10 minutes. The solution was diluted with ethyl acetate and 5M NH4OH added to adjust pH to 9. The mixture was transferred to a separatory funnel and the organic layer collected. The aqueous layer was further extracted with ethyl acetate and the combined organic layers were washed with brine, dried over magnesium sulphate, filtered, concentrated and the residue purified via chromatography on silica gel (EtOAc:methanol:Et3N, 8:1:1) to yield a pale yellow solid 81 (102 mg, 49.2%). 1H NMR (DMSO-d6) δ: 1.80-1.98 (m, 4H), 2.11 (dt, 2H, J=11.2, 3.5 Hz), 2.23 (s, 3H), 2.88 (d, 2H, J=11.6 Hz), 4.08-4.19 (m, 1H), 4.46 (brs, 2H), 6.13 (d, 1H, J=3.0 Hz), 6.51 (dd, 1H, J=8.8, 2.1 Hz), 6.67 (d, 1H, J=2.0 Hz), 7.18 (d, 1H, J=8.6 Hz), 7.24 (d, 1H, J=3.1 Hz); EI-MS (m/z, %): 229 (M+, 100%).

Provenance & Evidence