“…The reaction of 1,10-phenanthroline (9.0 mg, 0.05 mmol), 2,2'-bipyridine (8.0 mg, 0.05 mmol), CuCl (9.8 mg, 0.10 mmol), K 2 CO 3 (34.2 mg, 0.25 mmol), dry toluene (2.5 mL), DBAD (22.7 mg, 0.10 mmol), and 1g (87.2 mg, 0.5 mmol)/dry toluene (2.5 mL) afforded 2g [28] . The reaction of 1,10-phenanthroline (4.4 mg, 0.025 mmol), 2,2'-bipyridine (3.8 mg, 0.025 mmol), CuCl (5.0 mg, 0.05 mmol), K 2 CO 3 (34.2 mg, 0.25 mmol), dry toluene (2.5 mL), DBAD (11.7 mg, 0.05 mmol), and 1g (87.0 mg, 0.5 mmol)/dry toluene (2.5 mL) afforded 2g [28] (71.2 mg, 83%) (eluent: petroleum ether∶ethyl acetate =30∶1): Liquid.…”