Reaction Steps
2,7-Dibromo-9,9-dioctylfluorene (2.00 g, 3.65 mmol, 1 eq.) was dissolved in diethyl ether (30 ml). The solution was cooled to −78° C. and n-butyllithium (2.4 mL of a 1.6 M solution in hexanes, 3.83 mmol, 1.1 eq.) was added drop wise with strong stirring. The resulted white suspension was allowed to warm to −10° C. until a clear-yellow solution 3 was formed. After stirring for another 10 min, the solution was cooled to −78° C. again and 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.82 mL, 4.0 mmol, 1.1 eq.) was added in one time. The mixture was stirring for another 1 h at −78° C. and was allowed to warm to 25° C. and stirred for 24 h, and then the reaction was quenched by 10 mL of water. The organic layer was washed thoroughly by water and was dried by anhydrous Na2SO4. After the solvent was removed under reduced pressure, the crude oil was separated by column chromatography with hexane/dichloromethane=4/1 (v/v) as eluent to give 1.42 g of white powder (yield=65%). 1H NMR (500 MHz, CDCl3) δ (ppm): 7.80 (d, J=7.55 Hz, 1H), 7.72 (s, 1H), 7.65 (d, J=7.55 Hz, 1H), 7.57 (d, J=7.80 Hz, 1H), 7.44 (m, 2H), 2.02-1.96 (m, 2H), 1.94-1.88 (m, 2H), 1.39 (s, 12H), 1.23-1.14 (m, 4H), 1.13-1.03 (m, 16H), 0.82 (t, J=7.15 Hz, 6H), 0.57 (m, 4H). 13C NMR (500 MHz, CDCl3) δ (ppm): 153.57, 149.50, 142.98, 139.97, 133.88, 129.89, 128.86, 126.23, 121.52, 121.44, 119.02, 83.78, 55.47, 53.41, 40.12, 31.77, 29.21, 29.18, 24.97, 23.61, 22.59, 14.06.
