Cycloaddition Reaction Of Enamines Research Articles

Cycloaddition Reactions of Enamines

AbstractThis review includes information for around two last decades on cycloaddition reactions of enamines with various agents in order to build carbo‐ and heterocycles. In addition, the review presents organo‐catalytic reactions in which enamines are intermediate products generated in situ. This review covers the synthesis of four, five, six and eight‐membered carbocyclic compounds, as well as heterocycles as pyrroles, pyridines, etc.

The Rich Chemistry Resulting from the 1,3‐Dipolar Cycloaddition Reactions of Enamines and Azides

Enamines exhibit exceptionally high reactivity in their 1,3‐dipolar cycloaddition reactions with azides in comparison with other dipolarophiles. This review includes the reactions of various types of enamines with azides of different nature, including catalytic processes. The initial products of the reaction, 1,2,3‐triazolines, are generally unstable and very reactive compounds which are prone to undergo various ring transformations. This provides the background for new synthetic methods and novel reaction types. The formation of a variety of products derived from the reaction of enamines with azides such as mono‐, di‐and tri‐substituted 1,2,3‐triazoles, including N‐unsubstituted derivatives, fused, conjugated and spiro heterocycles, two types of amidines and diaminoalkenes are classified in this review according to the type of stabilization/transformation of the intermediate triazolines.

Synthesis of Assemblies of Isoxazole and Azoles Based on 1,3-Dipolar Cycloaddition Reaction of Enamines with Nitrile Oxides

2-(1,2,3-Thiadiazol-5-yl)enamines and 3-(1,2,3-triazol-4-yl)enaminones react with arylhydroxamoyl chlorides at room temperature with the exclusive formation of 3-aryl-4-(1,2,3-thiadiazol-5-yl)- and [4-(1,2,3-triazol-4-yl)carbonyl]isoxazoles in high yields. The proposed mechanism includes in situ generation of nitrile oxides, which participate in the (3+2)-dipolar cycloaddition reactions leading to the formation of the isoxazole ring.

ChemInform Abstract: Novel Methods for the Synthesis of 4‐(Azol‐5‐yl)isoxazoles.

AbstractThree title compounds of type (V) are prepared by the [3 + 2] cycloaddition reaction of enamines (III) and nitrile oxides generated in situ from hydroxamoyl chlorides.

Reactions of Conjugate Phosphinyl- and Phosphonyl-Nitroso Alkenes with Enamines. Preparation of N-Hydroxypyrrole Derivatives

The synthesis of highly functionalized N-hydroxypyrrole derivatives by the formal [3+2] cycloaddition reaction of enamines and nitroso alkenes derived from phosphine oxides and phosphonates is reported. Intermediate phosphorylated nitrones, whose formation can be explained by a conjugate addition of enamines to phosphorylated nitroso alkenes and formation of the five-membered heterocycles, are isolated.

Synthesis of C-ring substituted xanthones from the [4 + 2] cycloaddition reaction of vinylchromones and acyclic enamines

A novel approach to the synthesis of C-ring substituted xanthones utilising the [4 + 2] cycloaddition reactions of enamines with aromatically substituted vinylchromones has been developed. 1-Methyl-, 1-ethyl-, 2-methyl- and 2-ethyl-substituted xanthones are obtained in a one-pot synthesis from the reaction of pyrrolidine enamines derived from acetone, butan-2-one, propanal and butanal respectively, when taken as solvent incorporating a catalytic amount of pyrrolidine. Some 1-methylidene- and 1-methylidene-2-methyl-substituted tetrahydroxanthones were also obtained and these compounds are proposed to be intermediates in the reaction, since they undergo facile conversion to 1-methyl- and 1,2-dimethyl-xanthones. Further evidence for the proposed reaction pathway was obtained from the isolation of a 1-pyrrolidino-2,2-dimethyl substituted tetrahydroxanthone from the reaction between a vinylchromone and the pyrrolidine enamine of 2-methylpropanal.

Novel intramolecular [4 + 2] cycloaddition reactions of enamines and enamides with unactivated dienes

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNovel intramolecular [4 + 2] cycloaddition reactions of enamines and enamides with unactivated dienesStephen F. Martin, Chih-Yun Tu, and Ta-Shue ChouCite this: J. Am. Chem. Soc. 1980, 102, 16, 5274–5279Publication Date (Print):July 1, 1980Publication History Published online1 May 2002Published inissue 1 July 1980https://doi.org/10.1021/ja00536a026RIGHTS & PERMISSIONSArticle Views756Altmetric-Citations40LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (875 KB) Get e-Alerts Get e-Alerts

Intramolecular [4+2] cycloaddition reactions of enamines and enamides

An attempt to utilize a new strategy for alkaloid synthesis which features the intramolecular [4+2] cycloaddition of enamines and enamides for the construction of the tetracyclic spiroamine skeleton characteristic of the Erythrina alkaloids was unsuccessful, unexpectedly giving a bridged cycloadduct rather than a fused one.

Cycloaddition Reaction of Enamines with Diphenylcyclopropenone1

Cycloaddition Reaction of Enamines with Diphenylcyclopropenone¹