Electrochemical cyclization of tetramethyl esters of 2-substituted propane-1,1,3,3-tetracarboxylic acids in the presence of salts of hydrohalic acids
摘要:
The chemical and electrochemical cyclization of tetramethyl esters of 2-substituted propane-1,1,3,3-tetracarboxylic acids in the presence of hydrohalic acid salt mediators were studied. It was found that the chemical variant of the cyclization of the corresponding alpha,alpha'-dianions of esters of propane-1,1,3,3-tetracarboxylic acids by the action of iodine or bromine is substantially inferior to the electrochemical variant. In the latter case, the esters of substituted cyclopropane-1,1,2,2-tetracarboxylic acids are formed in a 87-98% yield. The tetramethyl ester of 2-isopropylpropane-1,1,3,3-tetracarboxylic acid, which under the electrolysis conditions decomposes according to a Michael retroreaction is an exception.
Iron-Catalyzed Oxidation of Tertiary Amines: Synthesis of β-1,3-Dicarbonyl Aldehydes by Three-Component C–C Couplings
摘要:
beta-1,3-Dicarbonyl aldehydes were synthesized by iron-catalyzed oxidative reactions between 1,3-dicarbonyl compounds and two molecules of tertiary amines in the presence of tert-butyl hydroperoxide (TBHP). alpha,beta-Unsaturated aldehydes generated by tertiary amine oxidation In situ act as key intermediates under mild reaction conditions.
The condensation of active methylene compounds 1 with acetaldehyde was efficiently promoted by a catalytic amount of lithium bromide in the presence of acetic anhydride to give ethylidene malonates 2 in 77-97% yield.
Conjugate intra- and intermolecular addition mediated by methoxide anion on polymeric support
作者:Cristiana Fava、Roberta Galeazzi、Eugenia Maria Gonzalez-Rosende、Mario Orena
DOI:10.1016/s0040-4039(00)01490-8
日期:2000.10
By treatment with methoxide anion on polymeric support (IRA 900), chiral beta -oxo or beta -sulphonylamides 2 bearing an alpha,beta -unsaturated ester gave 3,4-disubstituted pyrrolidin-2-ones 3 as easily separable diastereomeric mixtures in good yield and moderate-to-good stereoselection. The polymeric reagent was also effective in promoting both intermolecular conjugate addition and alkylation reactions. (C) 2000 Published by Elsevier Science Ltd.
EHLINSON, M. N.;FEDUKOVICH, S. K.;NIKISHIN, G. I., IZV. AN CCCP. CEP. XIM.,(1990) N2, S. 2783-2789
作者:EHLINSON, M. N.、FEDUKOVICH, S. K.、NIKISHIN, G. I.
DOI:——
日期:——
Electrochemical cyclization of tetramethyl esters of 2-substituted propane-1,1,3,3-tetracarboxylic acids in the presence of salts of hydrohalic acids
作者:M. N. Elinson、S. K. Fedukovich、G. I. Nikishin
DOI:10.1007/bf01184531
日期:1990.12
The chemical and electrochemical cyclization of tetramethyl esters of 2-substituted propane-1,1,3,3-tetracarboxylic acids in the presence of hydrohalic acid salt mediators were studied. It was found that the chemical variant of the cyclization of the corresponding alpha,alpha'-dianions of esters of propane-1,1,3,3-tetracarboxylic acids by the action of iodine or bromine is substantially inferior to the electrochemical variant. In the latter case, the esters of substituted cyclopropane-1,1,2,2-tetracarboxylic acids are formed in a 87-98% yield. The tetramethyl ester of 2-isopropylpropane-1,1,3,3-tetracarboxylic acid, which under the electrolysis conditions decomposes according to a Michael retroreaction is an exception.
Iron-Catalyzed Oxidation of Tertiary Amines: Synthesis of β-1,3-Dicarbonyl Aldehydes by Three-Component C–C Couplings
作者:Weiping Liu、Jinhua Liu、Daisuke Ogawa、Yasushi Nishihara、Xingwei Guo、Zhiping Li
DOI:10.1021/ol202749x
日期:2011.12.2
beta-1,3-Dicarbonyl aldehydes were synthesized by iron-catalyzed oxidative reactions between 1,3-dicarbonyl compounds and two molecules of tertiary amines in the presence of tert-butyl hydroperoxide (TBHP). alpha,beta-Unsaturated aldehydes generated by tertiary amine oxidation In situ act as key intermediates under mild reaction conditions.