Reaction Steps
4-Methoxy-benzylamine (1.77 mL, 1.87 g, 13.64 mmol) and anhydrous DMSO (2.90 mL) were added to a high-pressure flask charged with 30 (1.65 g, 5.26 mmol), K3PO4 (2.36 g, 11.10 mmol), CuII (167 mg, 0.88 mmol), and L-(−)-proline (141 mg, 1.22 mmol); the sealed flask was heated to 80° C. for 44 hours. After cooling to room temperature, reaction contents were partitioned between water (50 mL) and EtOAc (100 mL), then were extracted with EtOAc (2×100 mL). The combined organic layers were washed with saturated aqueous NaCl solution (200 mL), dried (Na2SO4), filtered, and concentrated. The residue was purified via column chromatography (SiO2, 1:1 Hexanes:EtOAc) to give 31 as a light yellow amorphous solid (1.43 g, 73%): 1H NMR (CDCl3, 500 MHz) δ 8.44 (d, J=2.8 Hz, 1H), 7.52 (d, J=8.9 Hz, 1H), 7.50 (m, 2H), 7.43-7.38 (m, 3H), 7.36-7.32 (m, 3H), 7.20 (dd, J=8.9, 2.6 Hz, 1H), 7.06 (d, J=2.7 Hz, 1H), 6.91 (m, 2H), 5.17 (s, 2H), 4.35 (d, J=4.8 Hz, 2H), 4.17 (bt, J=4.8 Hz, 1H), 3.82 (s, 3H); 13C NMR (CDCl3, 125 MHz) δ 159.3, 156.9, 143.4, 143.3, 140.5, 137.0, 130.6, 129.1 (2C), 128.8 (2C), 128.2, 127.9 (2C), 127.3, 124.7, 120.4, 114.4 (2C), 112.0, 109.0, 70.3, 55.5, 48.0; IR (film) νmax 3279, 2953, 2833, 1609, 1510, 1377, 1354, 1302, 1225, 1175, 1124, 1028, 995, 868, 818, 762, 708 cm−1; HRMS (ESI+) m/z: [M+H]+ calcd for C24H22N2O2, 371.1759. found, 371.1732.
