*3-(Phenylethynyl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane-2-yl)-benzonitrile (19)*

The general procedure B was applied to 3-bromobenzonitrile (910 mg, 5.0 mmol, 1 equiv). The borylation step was carried out with HBpin (1.09 mL, 960 mg, 7.5 mmol, 1.5 equiv), [Ir(OMe)(COD)]2 (50 mg, 0.075 mmol, 3 mol % Ir), and dtbpy (40 mg, 0.15 mmol, 3 mol %) at room temperature for 12 h. The Sonogashira coupling step was carried out with phenyl acetylene (604 μL, 562 mg, 5.50 mmol, 1.1 equiv) for 24 h. After completion, 20 mL of water were added to the reaction mixture. The reaction mixture was extracted with ether (100 mL). The combined ether extractions were washed with brine (25 mL), followed by water (20 mL) and dried over MgSO4. Filtration and concentration under reduced pressure on a rotary evaporator furnished the desired product as a light yellow solid (1.652 g, 71% yield, mp 83–85 ◦C).

1H-NMR (CDCl3, 300 MHz): δ 8.16 (dd, *J* = 1.7, 1.1 Hz, 1 H), 8.01 (dd, *J* = 1.7, 1.1 Hz, 1 H), 7.85 (t, *J* = 1.7 Hz, 1 H), 7.59–7.46 (m, 2 H), 7.42–7.31 (m, 3 H), 1.36 (br s, 12 H, 4 CH3 of Bpin); 13C-NMR {1H} (CDCl3, 75 MHz): δ 141.8 (CH), 137.5 (CH), 136.9 (CH), 131.9 (2 CH), 129.0 (CH), 128.6 (2 CH), 124.6 (C), 122.6 (C), 118.2 (C), 112.7 (C), 91.9 (C), 87.2 (C), 84.9 (2 C), 25.0 (4 CH3 of Bpin); 11B NMR (CDCl3, 160 MHz): δ 29.7; FT-IR (neat) Іmax: 3061, 2980, 2932, 2231 (s), 2212 (w), 1589, 1491, 1415, 1377, 1329, 1298, 1143, 1122, 966, 897, 848, 756, 698, 690 cm<sup>−</sup>1; GC-MS (EI) *m*/*z* (% relative intensity): M<sup>+</sup> 329 (100), 314 (8), 244 (46), 230 (27); HRMS (FAB): *m*/*z* 330.1668 [(M<sup>+</sup>); Calcd for C21H21BNO2: 330.1665].
