Novel Synthesis of Oxygenated Coumarins from Substituted Phenols Mediated by Vinyl Triphenylphosphonium Salt Under Microwave Irradiation
摘要:
Protonation of the highly reactive 1:1 intermediates produced in the reaction between triphenylphosphine and dimethyl acetylenedicarboxylate(DMAD) by substituted phenols lead to vinyl triphenylphosphonium salts, which undergo aromatic electrophilic substitution reaction with a phenolate conjugate base to produce. 4-carboxymethyl coumarins in fairly highly yields.
A new and efficient route to 4-carboxymethylcoumarins mediated by vinyltriphenylphosphonium salt
作者:Issa Yavari、Rahim Hekmat-Shoar、Afsaneh Zonouzi
DOI:10.1016/s0040-4039(98)00206-8
日期:1998.4
Protonation of the reactive 1:1 intermediate produced in the reaction between triphenylphosphine and dimethyl acetylenedicarboxylate by substituted phenols leads to a vinyltriphenylphosphonium salt, which undergoes aromatic electrophilic substitution reaction with the phenolate conjugate base to produce 4-carboxymethylcoumarins in fairly high yields. (C) 1998 Elsevier Science Ltd. All rights reserved.
Novel Synthesis of Oxygenated Coumarins from Substituted Phenols Mediated by Vinyl Triphenylphosphonium Salt Under Microwave Irradiation
Protonation of the highly reactive 1:1 intermediates produced in the reaction between triphenylphosphine and dimethyl acetylenedicarboxylate(DMAD) by substituted phenols lead to vinyl triphenylphosphonium salts, which undergo aromatic electrophilic substitution reaction with a phenolate conjugate base to produce. 4-carboxymethyl coumarins in fairly highly yields.
TRIPHENYPHOSPHINE-MEDIATED EFFICIENT SYNTHESIS OF FUNCTIONALIZED 2-OXO-2<i>H</i>-CHROMENES
作者:Issa Yavari、Rahebeh Amiri、Mina Haghdadi
DOI:10.1080/10426500490474798
日期:2004.11.1
Dimethyl acetylenedicarboxylate reacts smoothly with phenol derivatives, such as 4-chloro-3,5-dimethylphenol, 2-chloro-5-methylphenol, 4-chloro-2-methylphenol, 2,4-dichlorophenol, or 2-bromophenol in the presence of triphenylphosphine to produce highly functionalized 2-oxo-2H-chromeus (counarins) in moderate yields.