Michael reaction of indoles with 3-(2′-nitrovinyl) indole under solvent-free conditions and in solution. An efficient synthesis of 2, 2-bis (indolyl) nitroethanes and …
Michael reaction of 3-(2′-nitrovinyl) indole with eight 3-unsubstituted indoles on TLC-grade silica gel furnished unsymmetrical bis (indolyl) nitroethanes in 7–12 min under microwave irradiation and in 8–14 h at rt. In contrast, the p-TsOH-catalysed reaction of the nitrovinylindole with the 3-unsubstituted and two 3-substituted indoles in solution under reflux furnished both unsymmetrical and symmetrical bis (indolyl) nitroethanes, the latter ...