## 3 Materials and Methods
#### Synthesis of the Starting Substrates
\({}^{1}\)H NMR (400 MHz, DMSO-\(d_{6}\)) \(\delta\) = 12.12 (s, 2H), 8.38 (s, 1H), 8.37 (s, 1H) 8.32-8.30 (m, 2H), 7.64 (d, \(J\) = 8.4 Hz, 2H), 7.61-7.59 (m, 4H), 7.33-7.27 (m, 6H), and 4.29 (s, 2H) ppm; \({}^{13}\)C\({}^{\{1}\)H\(\}\) NMR (100 MHz, DMSO-\(d_{6}\)) \(\delta\) = 147.3, 137.5, 136.6, 134.3, 132.7, 129.8, 124.8, 123.9, 123.0, 121.2, 120.0, 113.5, 113.2, 112.7, 101.6, and 41.0 ppm. HRMS (ESI) calcd for C\({}_{31}\)H\({}_{24}\)N\({}_{6}\) [M+2H]\({}^{+}\) 240.1026; found 240.0974. _2-(1H-indol-3-yl)-1H-imidazole[4,5-b]phenazine_ (**3 am**). A yield of 0.261 g (60%), 9.5 h, dark-brown solid. Mp. = 330 \({}^{\circ}\)C, decomposition (acetone). \({}^{1}\)H NMR (400 MHz, DMSO-\(d_{6}\)) \(\delta\) = 12.88 (brs, 1H), 11.99 (s, 1H), 8.64-8.63 (m, 1H), 8.45 (s, 1H), 8.22-8.20 (m, 4H), 7.85-7.83 (m, 2H), 7.59-7.57 (m, 1H), and 7.31-7.29 (m, 2H) ppm; \({}^{13}\)C\({}^{\{1}\)H\(\}\) NMR (100 MHz, DMSO-\(d_{6}\)) \(\delta\) = 157.7, 141.3, 140.4, 136.7, 129.6, 129.0, 128.7, 125.3, 122.7, 121.5(DMAC/H\({}_{2}\)O). \({}^{1}\)H NMR (400 MHz, DMSO-\(d_{6}\)) \(\delta\) = 11.94 (s, 1H), 8.63-8.62 (m, 1H), 8.25 (d, \(J\) = 2.4 Hz, 1H), 7.78-7.77 (m, 1H), 7.55 (d, \(J\) = 8.8 Hz, 1H), 7.51 (d, \(J\) = 8.8 Hz, 1H), and 7.38-7.32 (m, 2H) ppm; \({}^{13}\)C[\({}^{1}\)H] NMR (100 MHz, DMSO-\(d_{6}\)) \(\delta\) = 149.5, 139.7, 139.6, 136.7, 136.6, 135.2, 128.7, 126.5, 125.0, 124.6, 123.0, 116.8 (br.s), 115.3 (br.s), 114.1, 113.9, 113.3, and 104.6 ppm. HRMS (ESI) calcd for C\({}_{15}\)H\({}_{10}\)Br\({}_{2}\)N\({}_{3}\) [M+H]\({}^{+}\) 389.9236; found 389.9225. _2-(1-Enzyl-1H-indol-3-yl)-5-methyl-1H-benzo[d]imidazole_ (**3a**). A yield of 0.421 g (96%), 6 h, white solid. Mp. = 196-197 \({}^{\circ}\)C (DMAC/H\({}_{2}\)O). \({}^{1}\)H NMR (400 MHz, DMSO-\(d_{6}\)) \(\delta\) = 8.47-8.45 (m, 1H), 8.27 (s, 1H), 7.64-7.62 (m, 1H), 7.48 (d, \(J\) = 8.0 Hz, 1H), 7.38-7.34 (m, 3H), 7.32-7.25 (m, 5H), 7.06 (d, \(J\) = 8.0 Hz, 1H), 5.56 (s, 2H), and 2.45 (s, 3H) ppm; \({}^{13}\)C[\({}^{1}\)H] NMR (100 MHz, DMSO-\(d_{6}\)) \(\delta\) = 147.8, 137.2, 137.1, 137.0, 136.5, 135.8, 135.7, 131.3, 130.1, 128.6, 127.6, 127.3, 125.2, 123.4, 122.6, 121.2, 120.8, 113.8, 113.3, 110.8, 104.8, 49.5, and 21.2 ppm. HRMS (ESI) calcd for C\({}_{23}\)H\({}_{20}\)N\({}_{3}\) [M+H]\({}^{+}\) 338.1652; found 338.1643. _2-(5-Bromo-1H-indol-3-yl)-6,7-dimethyl-1H-benzo[d]imidazole_ (**3a**). A yield of 0.415 g (94%), 5 h, light-beige solid. Mp. = 153-155 \({}^{\circ}\)C (DMAC/H\({}_{2}\)O). \({}^{1}\)H NMR (400 MHz, DMSO-\(d_{6}\)) \(\delta\) = 12.10 (br.s, 1H), 11.73 (s, 1H), 8.74-8.73 (m, 1H), 8.22 (s, 1H), 7.48 (d, \(J\) = 8.8 Hz, 1H), 7.34 (dd, \(J\) = 8.8 Hz, 1H), 7.34 (dd, \(J\) = 8.8, 2.0 Hz, 1H), 7.28 (br.s, 1H), 6.96 (d, \(J\) = 8.0 Hz, 1H), 2.52 (s, 3H), and 2.35 (s, 3H) ppm; \({}^{13}\)C[\({}^{1}\)H] NMR (100 MHz, DMSO-\(d_{6}\)) \(\delta\) = 148.1, 135.1, 127.0, 126.9, 124.6, 123.6, 123.3, 113.8, 112.7, 106.5, 18.9, and 13.5 ppm. HRMS (ESI) calcd for C\({}_{17}\)H\({}_{15}\)BrN\({}_{3}\) [M+H]\({}^{+}\) 340.0444; found 340.0450. _7-Bromo-2-(5-bromo-1-methyl-1H-indol-3-yl)-5-methyl-1H-benzo[d]imidazole_ isolated as a solute with DMAC (1:0.3 DMAC) (**3a**). A yield of 0.529 g (91%), 6 h, light-beige solid. Mp. = 114-116 \({}^{\circ}\)C (DMAC/H\({}_{2}\)O). \({}^{1}\)H NMR (400 MHz, DMSO-\(d_{6}\)) \(\delta\) = 8.69 (d, \(J\) = 2.0 Hz, 1H), 8.20 (s, 1H), 7.55 (d, \(J\) = 8.8 Hz, 1H), 7.41 (dd, \(J\) = 8.8, 2.0 Hz, 1H), 7.32 (s, 1H), 7.21 (s, 1H), 3.91 (s, 3H), and 2.42 (s, 3H) ppm; \({}^{13}\)C[\({}^{1}\)H] NMR (100 MHz, DMSO-\(d_{6}\)) \(\delta\) = 148.8, 135.8, 132.4, 131.6, 127.0, 125.1, 124.8, 123.5, 113.4, 112.4, 104.8, 33.2, and 20.7 ppm. HRMS (ESI) calcd for C\({}_{17}\)H\({}_{14}\)Br\({}_{2}\)N\({}_{3}\) [M+H]\({}^{+}\) 417.9549; found 417.9534. _2-(Benzofuran-2-yl)-1H-benzo[d]imidazole_ (**3a**) [69]. A yield of 0.173 g (57%), 8 h, yellow solid. Mp. = 209-210 \({}^{\circ}\)C (petroleum ether/EtOAc, lit. [70] 201 \({}^{\circ}\)C).