Synthesis of compounds 26, 27, 34–36, and 40. Reagents and conditions: (a) Zn, 1,2-dibromoethane, TMSCl, DMF, 60 °C for 30 min to activate zinc, then sonication with 14 for 30 min; (b) Pd2dba3, P(o-tolyl)3, DMF, rt, 42-57%; (c) H2 (balloon), Pd(OH)2/C, rt; (d) 1:1 6N HCl (aq)/1,4-dioxane, 60 °C, 1h, 28-91% (purification by prep. HPLC or crystallization).