Propyne → 4-(Tert-butyl-diphenyl-silanyloxymethyl)-2-prop-1-ynyl-pyridine

Participants

Reaction Conditions

Reaction Steps

A reaction tube is charged under an atmosphere of argon with 4-(tert-butyl-diphenyl-silanyloxymethyl)-2-chloro-pyridine (9.47 g, 24.79 mmol), palladium(II)-bis(triphenylphosphine)-dichloride (1.78 g, 2.49 mmol, 0.1 equiv), copper(I) iodide (477 mg, 2.49 mmol, 0.1 equiv), and triphenylphosphine (3.94 g, 14.9 mmol, 0.6 equiv). The tube is degassed by alternating three times between vacuum and argon. Diethylamine (39 ml) and N,N-dimethylformamide (2.0 ml), and propyne (50% in THF, 10.1 g, 247 mmol, 10 equiv) are added under an argon atmosphere. The tube is sealed, and the reaction mixture is heated under microwave irradiation for 20 minutes at 120° C. After cooling, the reaction mixture is poured into a semi-concentrated aqueous solution of NaHCO3. After three extractions with EtOAc, the combined organic layers are washed with brine, dried over Na2SO4, filtered and concentrated in vacuo. Purification via flash chromatography (gradient from hexane/EtOAc 100:0 to 50:50) affords the title compound (6.0 g, 63%). 1H NMR (400 MHz, d6-DMSO): δ=8.41 (d, J=5.0 Hz, 1H), 7.57-7.55 (m, 4H), 7.43-7.32 (m, 11H), 7.27 (d, J=5.0 Hz, 1H), 4.72 (s, 2H), 1.99 (s, 3H), 0.98 (s, 9H). MS (ES+): 386 (M+H)+.

Provenance & Evidence