intermediates, produced in the reactionbetweentriphenylphosphine and dialkyl acetylenedicarboxylates, by phenols (1-hydroxynaphthalene, 2-hydroxynaphthalene, 4-bromophenol, 2-hydroxybenzaldehyde, and 5-bromo-2-hydroxyben- zaldehyde) leads to vinyltriphenylphosphonium salts, which undergo electrophilic substitutionreaction with conjugate base to produce corresponding stabilized phosphorus ylides. Microwave was
Abstract A convenient one-potsynthesis of coumarin derivatives from the three-component reaction of triphenylphosphine, an acetylenicester, and a phenol (1-naphthol, 2-naphthol and benzo[1,3]dioxol-5-ol) in the presence of a catalytic amount (4.5 mol%) of ß-cyclodextrin as a nanocatalyst and nanoreactor is reported. This methodology is of interest due to the use of water in the presence of this “ß-cyclodextrin
MICROWAVE INDUCED SYNTHESIS OF COUMARINS FROM IN SITU GENERATED STABILIZED PHOSPHORUS YLIDES IN THE PRESENCE OF SILICA GEL POWDER IN SOLVENT-FREE CONDITIONS
作者:Ali Ramazani、Ali Souldozi
DOI:10.1080/10426500490422173
日期:2004.3.1
the reactionbetweentriphenylphosphine and dialkyl acetylenedicarboxylates, by phenols (1-hydroxynaphthalene, 2-hydroxynaphthalene and 4-bromophenol) leads to vinyltriphenylphosphonium salts, which undergo aromatic electrophilic substitutionreaction with conjugate base to produce corresponding stabilized phosphorus ylides. Microwave was found to catalyze conversion of the stabilized phosphorus ylides
Manganese(II) Sulfate Powder is an Efficient Catalyst for the Synthesis of Coumarins from <i>In Situ</i> Generated Stabilized Phosphorus Ylides in Solvent-Free Conditions
reactive 1:1 intermediates, produced in the reactionbetweentriphenylphosphine and dialkyl acetylenedicarboxylates, by phenols (1-hydroxynaphthalene, 2-hydroxynaphthalene, and 4-bromophenol) leads to vinyltriphenylphosphonium salts, which undergo aromatic electrophilic substitutionreaction with conjugate base to produce corresponding stabilized phosphorus ylides. Manganese(II) sulfate powder was found
摘要 三苯基膦与二烷基乙炔二羧酸酯反应产生的高反应性 1:1 中间体,由苯酚(1-羟基萘、2-羟基萘和 4-溴苯酚)质子化生成乙烯基三苯基鏻盐,与共轭物发生芳香族亲电取代反应。生成相应的稳定磷叶立德。发现硫酸锰 (II) 粉末可在 90°C 的无溶剂条件下催化稳定的磷叶立德转化为香豆素,原因是 1 小时的高转化率。还发现在无溶剂条件下,在无溶剂条件下,在硫酸锰 (II) 粉末存在下,微波可在 1 分钟内以 1 KW 的微波功率催化相同的反应。
Bartsch, Chemische Berichte, 1903, vol. 36, p. 1968