The general procedure for the synthesis of 4,4,5,5-tetramethyl-2-(2-methylnaphthalen-1-yl)-1,3,2-dioxaborolanes from isopropanol pinacol borate and 1-bromo-2-methylnaphthalene was as follows: 1,2-dibromoethane (ca. 0.3 ml) was added dropwise to 1000 cm3 THF solution containing 6.10 g (0.25 mol) of magnesium chips. The mixture was stirred for 10 minutes and then continued to stir vigorously for 3.5 hours at room temperature. Subsequently, 55.3 g (0.25 mol) of 1-bromo-2-methylnaphthalene was added and 46.5 g (250 mmol) of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborole was added all at once. The reaction mixture was stirred for 15 minutes and then the reaction was terminated by pouring into 1000 cm3 cold water. The product was extracted with 3 x 300 ml of ethyl acetate, the organic layers were combined, washed sequentially with water and brine, and dried over anhydrous MgSO? The solvent was removed by evaporation under reduced pressure to give a white solid. The solid was washed with 2×75 ml pentane and dried in vacuum to give the product 47.3 g in 70% yield. Elemental analysis (C17H21BO2) Calculated value: C, 76.14; H, 7.89. Measured value: C, 76.21; H, 7.96.1H NMR (CDCl?) δ: 8.12 (m, 1H, 8-H), 7.77 (m, 1H, 5-H), 7.75 (d, J=8.4 Hz, 1H, 4-H), 7.44 (m, 1H. 7-H), 7.38 (m, 1H, 6-H), 7.28 (d, J=8.4Hz, 1H, 3-H), 2.63 (s, 3H, 2-Me), 1.48 (s, 12H, CMe?CMe?).
