Synthesis
Under nitrogen protection, 5-bromobenzofuran (25 g, 0.126 mol), pinacol ester of bisboronic acid (38.67 g, 0.152 mol), Pd(dppf)Cl2 (3.11 g, 3 mol%), KOAc (37.36 g, 0.381 mol) and 1,4-dioxane (500 ml) were mixed. The reaction mixture was stirred at 130°C for 12 hours. After completion of the reaction, the reaction mixture was extracted with ethyl acetate and the organic phase was dried with anhydrous MgSO4. Purification by column chromatography (eluent: hexane/ethyl acetate=10:1, v/v) afforded 2-(benzofuran-5-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (23.23 g, 75% yield).
References
[1] Patent: JP2016/40292, 2016, A. Location in patent: Paragraph 0518-0520
[2] Patent: JP2015/527347, 2015, A. Location in patent: Paragraph 0131; 0132
[3] Patent: KR101599586, 2016, B1. Location in patent: Paragraph 0170-0174
[4] Patent: KR101879905, 2018, B1. Location in patent: Paragraph 1187-1191
[5] Organometallics, 2016, vol. 35, # 10, p. 1559 - 1564
