Intramolecular Cycloaddition of Geminal Dichloroazomethine Ylides to Multiple Carbon-Carbon Bonds

Geminal dichloroazomethine ylides generated by reaction of dichlorocarbene with Schiff bases derived from O-alkenyl- or O-alkynylsalicylaldehyde undergo intramolecular [3 + 2]-cycloaddition with participation of the olefinic or acetylenic dipolarophile to afford chromeno[4,3-b]pyrrole and chromeno[4,3-b]pyridine derivatives. The greatest yields of the intramolecular cycloaddition products were obtained from N-methyl-substituted dichloroazomethine ylides, whereas the main stabilization path of N-phenyl and N-tert-butyl derivatives was cyclization to geminal dichloroaziridines.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 4, 2005, pp. 571–577.Original Russian Text Copyright © 2005 by Khlebnikov, Voznyi, Novikov, Kostikov.     

Intramolecular 1,3-Dipolar Cycloaddition of Azomethine Ylides Generated from Ethoxycarbonylcarbenoids and Schiff Bases

Decomposition of ethyl diazoacetate in the presence of copper, copper acetylacetonate, or copper trifluoroacetylacetonate and ethyl 4-[2-(R-imino)phenoxymethyl]-2-butenoate leads to formation of chromeno-[4,3-b]pyrrole-2,3-dicarboxylic acid derivatives. The reactions involve intermediate formation of azomethine ylides which undergo regio- and stereoselective intramolecular cycloaddition at the C=C bond to afford chromeno[4,3-b]pyrroles. The steric structure of the product depends on the configuration of intermediate ylide and nature of the substituent at the ylide nitrogen atom.     

Intramolecular 1,3-Dipolar Cycloaddition of Azomethine Ylides Leading to Pyrido[2,3-b]quinolines

A convenient six-step route to the previously unknown 1H-pyrrolo[2,3-f]benzo[b][1,8]naphthyridine ring system using an intramolecular 1,3-dipolar cycloaddition of nonstabilized azomethine ylides has been described.     

Synthesis of Novel Trispiroheterocycles through 1,3-Dipolar Cycloaddition of Azomethine Ylides and Nitrile Oxide

The 1,3‐dipolar cycloaddition of an azomethine ylide generated by a decarboxylative route from sarcosine and isatin to 1‐benzyl‐3,5‐diarylmethylidene‐piperidin‐4‐ones afforded novel di‐spiro‐indolo/pyrrolidino/piperidines in moderate yields. Further cycloaddition of these di‐spiro compounds to nitrile oxide afforded tri‐spiro‐indolo/pyrrolidino/piperadino/isoxazolines in moderate yields with high regio‐ and stereoselectivity.     

Intramolecular 1,3-Dipolar Cycloaddition Reactions

The intramolecular 1,3-dipolar cycloaddition reaction of suitably functionalized 1,3-dipoles represents a general scheme for the synthesis of novel fused ring heterocycles. Such reactions of a number of 1,3-dipoles are summarized and the general outline and potential analogies for these reactions noted. While the immediate aim of this review is to survey and correlate published work, it is hoped that general and specific points in need of study will be revealed and will stimulate further work in this fertile field.     

非稳定型亚甲胺基叶立德参与的1,3-偶极环加成反应合成新型5-取代噁唑烷衍生物

以N-三甲基硅甲基苄胺,多聚甲醛和芳香醛为原料,磷酸为催化剂,经1,3-偶极环加成反应合成了6个5-取代噁唑烷衍生物(3a~3f,其中3c~3f为新化合物),收率57%~73%,转化率70%~90%,其结构经1H NMR,13C NMR和ESI-MS表征。     

1,3-Dipolar Cycloaddition of Azomethine Ylides Generated from Ketimines and Difluorocarbene to Symmetrically Substituted Olefins

Iminiodifluoromethanides generated from difluorocarbene and benzophenone or fluorenone imines enter into reaction of 1,3-cycloaddition with electron-deficient alkenes to furnish pyrrolidone derivatives. The generation of iminiodifluoromethanides from alkyl N-benzhydrylidene glycinates in the presence of dipolarophiles is liable to complication by a concurrent proton shift in the initial imine giving NH-azomethine ylide also capable of 1,3-dipolar cycloaddition resulting in a side product of pyrrolidone series. The use of active lead instead of lead powder as reductant for dibromodifluoromethane in generation of difluorocarbene permits suppressing formation of the side products in these reactions.     

Prototropic Generation of Azomethine Ylides from Esters of N-benzylideneaminoacids,and 1,3-Dipolar Cycloaddition Thereof

Esters of N-benzhydrylideneglycin and -alanine undergo prototropic isomerization to yield azomethine ylides that react stereoselectively with N-substituted maleimides and fumaronitrile affording pyrrole derivatives.     

1,3-Dipolar Cycloaddition of Azomethine Ylides Generated from Schiff Bases and Difluorocarbene to Symmetric Olefins

Difluoro(iminio)methanides generated by the action of difluorocarbene on Schiff bases react with derivatives of maleic and fumaric acids, following the 1,3-dipolar cycloaddition pattern to give 2,2-difluoropyrrolidines which were detected by gas chromatography-mass spectrometry. The final products are stereo-isomeric substituted 2-pyrrolidinones formed by hydrolysis of difluoropyrrolidines and their dehydrofluorination products, 2-fluoro-4,5-dihydropyrroles. The observed stereoselectivity of the cycloaddition suggests Z configuration of intermediate ylide and both endo- and exo-approach to the dipolarophile in the transition state corresponding to cycloaddition.     

1,3-Dipolar Cycloaddition of Difluoro-Substituted Azomethine Ylides. Synthesis and Transformations of 2-Fluoro-4,5-dihydropyrroles

2-Fluoro-4,5-dihydropyrrole-3,4-dicarboxylic acid derivatives were obtained by reaction of difluorocarbene with N-substituted ketone imines in the presence of fumaronitrile, maleonitrile, or dimethyl maleate. The reaction involves intermediate formation of azomethine ylides and their subsequent cycloaddition at the double bond. 11H-Dibenz[b,e]azepine and 3,4-dihydroisoquinolines react with difluorocarbene in the presence of fumaronitrile to give fluoro-substituted dibenzo[c,f]pyrrolo[1,2-a]azepine and pyrrolo[2,1-a]-isoquinoline derivatives. Treatment of 2-fluoro-4,5-dihydropyrrole-3,4-dicarbonitrile with amines and alkoxides affords the corresponding 2-amino- and 2-alkoxy derivatives, while its reactions with hydrazine hydrate and benzimidamide lead to formation of substituted pyrrolo[2,3-c]pyrazole and pyrrolo[2,3-d]-pyrimidine derivatives.     

非稳定型亚甲胺基叶立德参与的三组分1,3-偶极环加成反应合成新型四氢吡咯衍生物

N-三甲基硅甲基苄胺和多聚甲醛在磷酸催化下生成非稳定型亚甲胺基叶立德,继而与各种贫电子烯烃在温和条件下发生三组分1,3-偶极环加成反应,高收率合成了10个3,4-二取代四氢吡咯衍生物(其中6个为新化合物),其结构经1H NMR,13C NMR和HR-MS表征。     

First Example of 1,3-Dipolar Cycloaddition of Carbonyl Ylides to Cyclopropenes

Carbonyl ylide generated from 1-diazo-5-phenylpentane-2,5-dione in the presence of Rh₂(OAc)₄ reacts with 3-substituted cyclopropenes following the 1,3-dipolar cycloaddition pattern to afford substituted 9-oxatricyclo[3.3.1.0^2,4]nonan-6-ones.     

含氮Ylide对C_(60)的1,3-偶极环加成反应法合成含吡咯环C_(60)衍生物

利用肌氨酸与对位含不同取代基的苯甲醛、共轭烯烃醛类及酮类反应生成的含氮Ylide对C60的加成反应，合成并分离、纯化制得了一系列含不同取代基的C60吡咯环纯衍生物，并用1HNMR、13CNMR、FDMS、FT－IR、UV－Vis等光谱手段确定了它们的分子结构．     

Synthesis of Highly Substituted Pyrrolidines Through 1,3-Dipolar Cycloaddition Reaction of N-Metalated Azomethine Ylides with Triarylideneacetylacetone as Dipolarophile Using Titanocene Dichloride

The 1,3-dipolar cycloaddition reaction of tryarylideneacetyacetone derivatives with N-metalated azomethine ylides in the presence of titanocene dichloride and triethylamine has been investigated. This two-step synthetic sequence is very efficient and yielded the highly substituted pyrrolidines in good yields. The structure and stereochemistry of one of the products has been established by single-crystal x-ray structure and spectroscopic techniques.     

甲亚胺叶立德的1,3-偶极环加成反应合成螺吲哚里西啶类化合物

通过7-芳亚甲基-6,7-二氢中氮茚-8(5H)-酮与甲亚胺叶立德(经苊醌或靛红与肌氨酸反应原位生成)进行的l,3-偶极环加成反应,合成了具有良好产率的新的1’-甲基-4’-芳基-5",6"-二氢-2H,8"H-二螺[苊烯-1,2’-吡咯烷-3’,7"-中氮茚]-2,8"-二酮类化合物和1’-甲基-4’-芳基-5",6"-二氢-1H,8"H-二螺[吲哚-3,2’-吡咯烷-3’,7"-中氮茚]-2,8"-二酮类化合物.采用NMR,IR,质谱,元素分析以及X射线单晶衍射等多种谱学技术对产物进行了结构表征.     

Pyrrolodiazines. 2. Structure and Chemistry of Pyrrolo[1,2-a]pyrazine and 1,3-Dipolar Cycloaddition of Its Azomethine Ylides

A new synthesis of the pyrrolo[1,2-a]pyrazine system from pyrrole is described. In light of the ab initio calculations carried out on this heterocyclic system some of its basic chemistry was investigated and included electrophilic substitution, addition of organolithium reagents, metalation with lithium diisopropylamide and subsequent reaction with electrophiles, and formation of salts by quaternization of the nonbridgehead nitrogen. N-ylides obtained from these salts undergo 1,3-dipolar cycloaddition with suitable dipolarophiles to give dipyrrolo[1,2-a]pyrazines, pyrazolo[1,5-a]-pyrrolo[2,1-c]pyrazines, and heterobetaines. Examples of intramolecular 1,3-dipolar cycloadditions are also reported.