A solution of (S)-tert-butyl 2-(5-iodo-1H-imidazol-2-yl)pyrrolidine-1-carboxylate (1 g, 2.75 mmol), triethylamine (1.92 mL, 13.8 mmol) and copper(I) iodide (0.105 g, 0.551 mmol) in DMF (30 mL) was degassed under vacuum and backfilled with nitrogen. Ethynyltrimethylsilane (1.35 g, 13.8 mmol) and Pd(Ph3P)4 (0.159 g, 0.138 mmol) were added and then the reaction was sealed and heated at 50° C. for 1d. The reaction was concentrated to remove the volatiles and the residue was purified on a BIOTAGE® (silica gel, eluted with 0 to 40% ethyl acetate/hexanes) to yield (S)-tert-butyl 2-(5-((trimethylsilyl)ethynyl)-1H-imidazol-2-yl)pyrrolidine-1-carboxylate (751 mg, 2.25 mmol, 82% yield) as brownish foam.
