Reaction Steps
A Schlenk tube was charged with CuI (9.6 mg, 0.050 mmol, 5.0 mol %), 2-(3-bromophenyl)-5-(2-naphthyl)-1,3,4-oxadiazole (352 mg, 1.00 mmol), NaI (300 mg, 2.00 mmol), briefly evacuated and backfilled with argon. Racemic trans-N,N′-dimethyl-1,2-cyclohexanediamine (16 μL, 0.10 mmol, 10 mol %) and dioxane (1.0 mL) were added under argon. The Schlenk tube was sealed with a Teflon valve and the reaction mixture was stirred at 110° C. for 24 h. The resulting light green-gray suspension was allowed to reach room temperature, diluted with 30% aq ammonia (5 mL), poured into water (20 mL), and extracted with dichloromethane (3×15 mL). The combined organic phases were dried (Na2SO4), concentrated to ca. 2 mL volume. The product was allowed to crystallize at room temperature. After 15 min, hexane (20 mL) was added, the mixture was kept at room temperature for 15 h, and finally filtered to provide 382 mg (96% yield) of 2-(3-iodophenyl)-5-(2-naphthyl)-1,3,4-oxadiazole as white, fine needles. Mp: 156-158° C. 1H NMR (400 MHz, CDCl3): δ 8.64 (s, I H), 8.53 (t, J=1.8 Hz, 1H), 8.22 (dd, J=8.6, 1.8 Hz, 1H), 8.18 (dt, J=7.9, 1.2 Hz, 1H), 8.03-7.93 (m, 2H), 7.95-7.88 (m, 2H), 7.65-7.53 (m, 2H), 7.30 (t, J=7.9 Hz, 1H). 13C NMR (100 MHz, CDCl3): δ 165.1, 163.2, 140.6, 135.5, 134.8, 132.8, 130.7, 129.1, 128.9, 128.1, 128.0, 127.5, 127.2, 126.1, 125.8, 123.2, 120.8, 94.4. IR (neat, cm−1): 1558, 1540, 753, 731. Anal. Calcd. for C18H11IN2O: C, 54.29; H, 2.78. Found: C, 54.29; H, 2.74.
