Synthesis of Diels–Alder adducts of N-arylmaleimides by a multicomponent reaction between maleic anhydride, dienes, and anilines
作者:J. Alberto Guevara-Salazar、Delia Quintana-Zavala、Hugo A. Jiménez-Vázquez、José Trujillo-Ferrara
DOI:10.1007/s00706-011-0515-5
日期:2011.8
AbstractWe have carried out the synthesis and characterization of some hexahydroisoindolyl benzoic acids and their corresponding ethyl esters by a multicomponent reaction (MCR) between aminobenzoic acids or aminobenzoates, maleicanhydride, and isoprene in the absence of catalysts. According to additional experiments, the MCR takes place by sequential formation of N-arylmaleamic acids from the aminobenzoic
摘要我们在不存在催化剂的情况下,通过氨基苯甲酸或氨基苯甲酸酯,马来酸酐和异戊二烯之间的多组分反应(MCR),对一些六氢异吲哚基苯甲酸及其相应的乙酯进行了合成和表征。根据其他实验,MCR是通过依次从氨基苯甲酸或氨基苯甲酸酯和顺丁烯二酸酐,酸和异戊二烯的Diels–Alder加合物,最后是酰亚胺形成N-芳基马来酰胺酸而发生的。加合物的1 H NMR数据(耦合常数)表明,相应的环己烯环的优选构型是顺式-船,由密度泛函理论(DFT)构象分析和相应构象异构体自旋-自旋耦合常数的DFT计算所支持的事实。我们的MCR合成方法在其他加合物的合成中成功进行了测试,其中使用了环戊二烯和其他苯胺。 图形概要
Cationic Chiral Fluorinated Oxazaborolidines. More Potent, Second-Generation Catalysts for Highly Enantioselective Cycloaddition Reactions
作者:Karla Mahender Reddy、Eswar Bhimireddy、Barla Thirupathi、Simon Breitler、Shunming Yu、E. J. Corey
DOI:10.1021/jacs.6b00100
日期:2016.2.24
placement of fluorine substituents in the chiral ligand. This approach has led to a new, second-generation family of chiral oxazaborolidinium cationic species which can be used to effect many Diels-Alder reactions in >95% yield and >95% ee usingcatalyst loadings at the 1-2 mol % level. The easy recovery of the chiral ligand makes the application of these new catalysts especially attractive for large-scale
Highly Enantioselective Diels−Alder Reactions of Maleimides Catalyzed by Activated Chiral Oxazaborolidines
作者:Santanu Mukherjee、E. J. Corey
DOI:10.1021/ol902865d
日期:2010.2.5
Diels−Alder reactions of various combinations of maleimides and 1,3-dienes with cationic oxazaborolidines as catalysts have been shown to be highly efficient and enantioselective.
Oxathiaborolium-Catalyzed Enantioselective [4 + 2] Cycloaddition and Its Application in Lewis Acid Coordinated and Chiral Lewis Acid Catalyzed [4 + 2] Cycloaddition
作者:Ramalingam Boobalan、Rong-Jie Chein
DOI:10.1021/acs.orglett.1c02345
日期:2021.9.3
catalysts for [4 + 2] cycloaddition. Oxathiaborolium pentachlorostannate (5–10 mol %) successfully catalyzed cycloaddition of various dienes and dienophiles to afford cycloadducts with excellent enantioselectivity (20 examples, up to 99% ee). This super Lewis acid also exhibited good enantioselectivity for the first Lewis acid coordinated and chiral Lewis acid catalyzed [4 + 2] cycloaddition to α,β-unsaturated
Investigation of the Cyclopentenone Formationvia the ?-Alkynone Cyclisation: Synthesis of the Acorone Intermediate 8-Methylspiro[4.5]deca-3,7-dien-2-one
作者:John Ackroyd、Martin Karpf、Andr� S. Dreiding
DOI:10.1002/hlca.19850680208
日期:1985.3.27
of the cyclopentenone formation ACvia the thermal α-alkynone cyclisation BC and in order to test the fate of an isolated C,C-double bond within a molecule under these conditions, we investigated the synthesis of the acorone intermediate 3starting from the known carboxylic acid 1. The α-alkynone 2 was obtained from 1via the acyl chloride 6 and a Pd(II)-catalysed route (22%). The thermolysis of 2 at