To 5-methoxy-1-(triisopropylsilyl)-1H-pyrrolo[3,2-b]pyridin-6-ylboronic acid (900 mg, 2.58 mmol) was added sodium carbonate (548 mg, 5.17 mmol), lithium chloride (219 mg, 5.17 mmol), tert-butyl 4-(trifluoromethylsulfonyloxy)-5,6-dihydropyridine-1(2H)-carboxylate (856 mg, 2.58 mmol) and deairared 1,4-dioxane (15 mL) at rt temperature, followed by tetrakis(triphenylphosphine)palladium(0) (149 mg, 0.1297 mol), and H2O (1 mL). The resulting light brown mixture was stirred at 80° C. for 2 hr, and the conversion was completed as determined by LC/MS. After cooling down to rt, the mixture was partitioned between H2O/EtOAc (50 mL/100 mL). After separation, the organic phase was washed with brine, dried (Na2SO4), concentrated on rotary vacuo, and purified on Biotage Flash Collector eluting with 30-80% EtOAc/Hexanes (1200 mL) to afford the expected product, tert-butyl 4-(5-methoxy-1-(triisopropylsilyl)-1H-pyrrolo[3,2-b]pyridin-6-yl)-5,6-dihydropyridine-1(2H)-carboxylate (998 mg, 80%) as a white solid. 1H-NMR (400 MHz, MeOD) δ ppm 1.12 (s, 18 H) 1.49 (s, 9 H) 2.52 (s, 2 H) 3.47 (s, 3 H) 3.62 (s, 2 H) 4.00 (s, 3 H) 4.09 (s, 2 H) 5.78 (s, 1 H) 6.65 (s, 1 H) 7.33(s, 1 H) 7.51 (s, 1 H). Mass spec 486.28 (MH+) Calc for C27H43N3O3Si 485.31.
