Intramolecular cyclization of N-propargylic β-enaminones catalyzed by silver
摘要:
The efficient synthesis of 1,2-dihydropyridine from the intramolecular cyclization reaction of N-propargylic beta-enaminones [(RC)-C-2(O)CH=C(R-1)(N(R)CH2C=CH), where R = Pr, Bn, Ph, 4-Me-C6H4, R-1 = Me, Et, Pr, R-2 = CF3, CO2Et] using AgNO3 as a catalyst (12 h at 25 degrees C) is reported. The products were obtained at good yields (70-90%). In particular, when the reaction of N-propargylic beta-enaminone with R = Me was performed over a 24 h period, the intramolecular cyclization resulted in the formation of a pyrrole with 80% yield. 0 2012 Elsevier Ltd. All rights reserved.