Scheme. (1) Reagents and conditions: a) bis(pinacolato)diboron, K2CO3, Pd(PPh3)2Cl2, PPh3, dioxane, 50 °C, b) imidazole, K2CO3, acetone, rt, 37% for 19; c) bis(tributyltin), Pd(PPh3)2Cl2, DMF, 95 °C, 24 h, 74%; d) 21a, b, Pd(CH3CN)2Cl2, LiCl, DMF, 105 °C, 72 h, 38% for 24a, 36% for 24b; e) LiOH, MeOH-THF-H2O, rt, 18 h, 92% for 25a, 88% for 25b, 84% for 27; f) 3,4-methylenedioxyphenethylamine, TBTU, iPr2NEt, CH3CN, rt, 48 h, 88% for 3, 92% for 6, 70% for 9; g) H2 (1 atm), Pd/C, rt, 72 h, > 90%; h) DBU, PhH, reflux, 48 h, 90%; i) 2-ethoxycarbonyl-phenylzinc bromide, Pd(PPh3)4, THF, 50 °C, 48 h, 87%.

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