Scheme 2. Transformations of 3m. (a) Carbazole (1.2 equiv.), Pd2(dba)3 (5 mol%), P(tBu)3 (8 mol%), LiOtBu (4.5 equiv.), o-xylene, 140 °C, 24 h; (b) phenylacetylene (1.2 equiv.), PdCl2(PPh3)2 (5 mol%), CuI (10 mol%), Et3N (5.0 equiv.), DMF, 60 °C, 16 h; (c) B2pin2 (1.1 equiv.), Pd(dppf)Cl2 (10 mol%), KOAc (3.0 equiv.), toluene, 90 °C, 18 h; (d) styrene (1.2 equiv.), PdCl2(PPh3)2 (10 mol%), K2CO3 (4.0 equiv.), toluene, 130 °C, 12 h; (e) NiCl2 (1.0 equiv.), PPh3 (4.0 equiv.), Zn (1.0 equiv.), DMF, 50 °C, 12 h.
