Reaction Steps
A 50-mL three-neck round-bottomed flask equipped with a reflux condenser, magnetic stirrer and nitrogen inlet was charged with of 2-(3-bromo-2-methylphenyl)-3,4,6,7,8,9-hexahydropyrazino[1,2-a]indol-1(2H)-one 101l (600 mg, 1.67 mmol), 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi(1,3,2-dioxaborolane (1.70 g, 6.70 mmol), potassium acetate (656 mg, 6.68 mmol), and 1,4-dioxane (25 mL). After bubbling nitrogen through the resulting suspension for 30 min, XPhos (159 mg, 0.334 mmol) and tris(dibenzylideneacetone)dipalladium(0) (153 mg, 0.167 mmol) were added, and the reaction mixture was heated at 105° C. (oil bath temperature) for 14 h. After this time, the mixture was cooled to room temperature and filtered. The filtrate was diluted with ethyl acetate (75 mL) and water (20 mL). The organic layer was separated, and the aqueous layer was extracted with ethyl acetate (3×25 mL). The combined organic layers were dried over sodium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography to afford a 109% crude yield (740 mg) of 2-(2-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-3,4,6,7,8,9-hexahydropyrazino[1,2-a]indol-1(2H)-one 101m as a yellow oil: 1H NMR (300 MHz, CDCl3) d 7.75 (dd, 1H, J=6.6, 2.1 Hz), 7.26 (m, 2H), 6.80 (s, 1H), 4.10 (m, 3H), 3.75 (m, 1H), 2.54 (m, 4H), 2.45 (s, 3H), 1.87 (m, 2H), 1.75 (m, 2H), 1.25 (s, 12H); MS (APCI+) m/z 407.7 (M+H)
