1-Butynyltrimethylsilane → tert-Butyl 5-(but-1-yn-1-yl)-7-fluoro-1H-indole-1-carboxylate

Participants

Reaction Steps

To a degassed (3× vacuum/nitrogen cycles) solution of TBAF (4.0 mL, 0.5 M THF, 2.00 mmol), but-1-yn-1-yltrimethylsilane (267 mg, 2.11 mmol; Intermediate 39) was added. The solution was stirred at room temperature for a few minutes before transferring into a reaction vessel containing tert-butyl 7-fluoro-5-iodo-1H-indole-1-carboxylate (360 mg, 1.00 mmol), Pd(PPh3)4 (232 mg, 0.20 mmol), and CuI (76 mg, 0.40 mmol). The reaction mixture was stirred at room temperature overnight, diluted with ethyl acetate (100 mL), washed (50 mL water then 50 mL brine), dried over Na2SO4, and concentrated under reduced pressure. The residue was purified by silica gel chromatography to yield the title compound as brown oil (260 mg, 91%). 1H NMR (300 MHz, DMSO-d6): δ 7.85 (d, 1H), 7.58 (d, 1H), 7.21 (dd, 1H), 6.83 (dd, 1H), 2.51 (q, 2H), 1.68 (s, 9H), 1.26 (t, 3H).

Provenance & Evidence