The electrochemical properties of tetracyclic dihydroindoloquinazoline and bicyclic dihydroquinazoline derivatives of type 1 and 2 have been studied in dichloromethane, both on Pt and glassy carbon anodes. Cyclic voltammetric results are discussed in terms of substituent and steric effects on the first and second anodic peak potentials. Anodic oxidation of type 1 compounds yields purple solutions (presumable cation radical species), regardless of the nature of the substituent. Exposure of the purple solutions to both light and air results in the formation of decomposition products: benzophenone and cyclic amides of type 4 (the X-ray crystal structure of 4c has been determined). On anodic oxidation, both 2b and 2c undergo mostly ring-closure to form the tetracyclic derivatives 1b and 1c, respectively, whereas 2d, which does not undergo cyclization, yields the bicyclic amide 5d. The mechanism of the formation fo products is discussed.

The electrochemical properties of tetracyclic dihydroindoloquinazoline and bicyclic dihydroquinazoline derivatives of type 1 and 2 have been studied in dichloromethane, both on Pt and glassy carbon anodes. Cyclic voltammetric results are discussed in terms of substituent and steric effects on the first and second anodic peak potentials. Anodic oxidation of type 1 compounds yields purple solutions (presumablycation radical species), regardless of the nature of the substituent. Exposure of the purple solutions to both light and air results in the formation of decomposition products: benzophenone and cyclic amides of type 4 (the X-ray crystal structure of 4c has been determined). On anodic oxidation, both 2b and 2c undergo mostly ring-closure to form the tetracyclic derivatives 1b and 1c, respectively, whereas 2d, which does not undergo cyclization, yields the bicyclic amide 5d. The mechanism of the formation of products is discussed.

Aryl-substituted ketene imines (1a–1i) have been studied both in dichloromethane and acetonitrile by cyclic voltammetry. In addition to the multi-annulated heterocycles products of type 2–4 previously obtained by ketene imines 1a–1d, the anodic oxidation of ketene imines containing electron-withdrawing substituents and electron-donating substituents at the ortho position, affords also monocyclic dimers of type 5 (from 1e–1f) and of type 6 (from 1h–1i). The results are discussed in terms of both electronic and steric effects.

The electrochemical generation of stable carbocations, among other heterocyclic products, by a unique electrochemical process involving the anodic oxidation of aryl-substituted ketene imines is described. The electrochemical oxidation undergoes an unusual multiannulation process to form these types of products by intermolecular cyclization. The X-ray crystal structures of two carbocation tetrafluoroborate salts,4c and4d, of which the latter is solvated by CH2Cl2, are presented. We have observed that one of the B-F bonds in4c is relatively long with respect to the other three similar in length B-F bonds, while in the solvated salt (4d·CH2Cl2), one of the B-F bonds is particularly short relative to its congeners. In both cases, the “exceptional” B-F bonds are oriented toward the positive center of the carbocation. These phenomena are compared with other known X-ray structures of organic tetrafluoroborate salts and discussed.

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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIntermolecular cyclization processes in the anodic oxidation of ketene imines: formation of heterocyclic dimers and trimersJames Y. Becker, Elias Shakkour, and J. A. P. R. SarmaCite this: J. Org. Chem. 1992, 57, 13, 3716–3720Publication Date (Print):June 1, 1992Publication History Published online1 May 2002Published inissue 1 June 1992https://doi.org/10.1021/jo00039a038RIGHTS & PERMISSIONSArticle Views102Altmetric-Citations12LEARN 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 (625 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The electrochemical oxidation of cyclic peralkylsilanes undergo ring opening followed by further SiSi bond cleavage and reaction with BF4- to form α,ω-difluorosilanes, F-(SiR2)n-F, as major products.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The one-pot one-component unique electrochemical synthesis of tetra- and bi-heterocycles by anodic oxidation of aryl-substituted ketene imines is described; the X-ray crystal structure of one of the heterocyclic products is presented.