tert-Butyl N-[[3-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]oxetan-3-yl]methyl]carbamate (65 mg, 0.1670 mmol) was dissolved in dioxane (3 mL) and 4-iodo-3-(trifluoromethyl)-1-trityl-pyrazolo[3,4-b]pyridine (92.74 mg, 0.1670 mmol) was added followed by sodium carbonate (250.5 μL of 2 M, 0.5010 mmol). The reaction was degassed and filled with nitrogen 5 times then Pd[P(tBu)3]2 (12.80 mg, 0.02505 mmol) was added. The reaction was heated at 60° C. overnight. After cooling, water was added followed by ethyl acetate. The aqueous layer was extracted three times with ethyl acetate, the combined organics washed with brine, dried over MgSO4, filtered and the solvent removed under reduced pressure. The crude product was purified on silica (Companion, 12 g) eluting with 2.5-50% EtOAc:Pet.ether to give tert-butyl N-[[3-[3-[3-(trifluoromethyl)-1-trityl-pyrazolo[3,4-b]pyridin-4-yl]phenyl]oxetan-3-yl]methyl]carbamate as a white foam (58 mg, 50%).
