In a 3-neck, 500 mL round-bottom flask, 1,3-dibromodibenzo[b,d]furan-2-amine (19.24 g, 56.4 mmol), 4,4,5,5-tetramethyl-2-(prop-1-en-2-yl)-1,3,2-dioxaborolane (30 g, 179 mmol), dicyclohexyl(2′,6′-dimethoxybiphenyl-2-yl)phosphine (1.85 g, 4.51 mmol), benzaldehyde (5.7 mL, 56.4 mmol), potassium phosphate monohydrate (52 g, 226 mmol), toluene (400 mL), and water (40 mL) were mixed. Nitrogen was bubbled directly into the mixture for 15 minutes, then Pd2(dba)3 (1.03 g, 1.13 mmol) was added. The reaction mixture was heated to reflux overnight. After cooled to room temperature, the organic layer was separated. 40 mL of concentrated HCl was added to the organic layer. The mixture was vigorously stirred for 1 h. Aqueous sodium hydroxide solution was added to basify the mixture. The organic layer was separated and purify by silica gel plug eluting with 1:1 dichloromethane/hexanes 19.1 g of a brown oil was obtained.
