FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W181606543> ?p ?o ?g. }

• W181606543 abstract "2,5-disubstituted tetrazoles decompose thermally to give nitrilimines (R1–CNN–R2), whose electronic structure widely varies with the substituents R1 and R2. In particular, for R1, R2 = H, the carbenic contribution to the resonance structure is small, while for NH2-disubstitution Natural Resonance Theory predicts 70% carbene character. This has large implications for the reactivities of substituted nitrilimines. The goal of this work is to identify nitrilimines with large carbenic contributions to their resonance structure that can undergo [1+2] cycloaddition reactions with unsaturated systems, in contrast to the common [3+2] cycloadditions of nitrilimines with only a small carbenic character.In this study, twelve tetrazoles known in the literature have been analyzed with respect to changes in geometry and orbital interactions. A Natural Bond Orbital analysis of the corresponding nitrilimines indicates that several possess an electron lone pair on carbon, which could be indicative of a sizeable carbenic contribution to the resonance structure. Based on this finding, the decomposition of the respective tetrazoles has been investigated. We have shown that, depending on the substituents, decomposition is either stepwise or concerted: C-substituted tetrazoles with electron donating groups follow a concerted pathway while electron withdrawing groups promote a stepwise path.Nitrilimines have been widely used in 1,3-dipolar ([3+2]) cycloadditions, in which they add to a dipolarophile, typically an alkene or alkyne, to form five-membered heterocyclic rings. In fact, all nitrilimines studied experimentally to date have been shown to undergo [3+2] cycloaddition reactions and their mechanism has been extensively studied in the past. On the other hand, nitrilimines can be described through a carbenic valence-bond structure, and while intermolecular carbenic reactions from nitrilimines are unknown, intramolecular reaction products from ortho-vinyl MeCOO–CNN–Ph and Ph–CNN–Ph that seem to have followed two typical carbene reaction mechanisms, [1+2] cycloaddition and C–H insertion, have been reported. In an attempt to promote the intermolecular [1+2] cycloaddition, reactions of F–CNN–F and NH2–CNN–NH2, both possessing substantial carbenic character, with ethene and electron-poor alkenes were compared to those for the unsubstituted H–CNN–H with smaller carbene character. The intermolecular [1+2] reaction is observed for H–CNN–H and F–CNN–F with tetrafluoroethene. NH2–CNN–NH2, as a nucleophilic species and possibly a stable carbene, does not tend to react with alkenes. To render these findings feasible for experiments, the carbenic character of readily accessible nitrilimines was determined from natural resonance theory.Nitrilimines with even a small carbenic character can undergo [1+2] cycloaddition with tetrafluoroethene. For example, COOH–CNN–OH and CHO–CNN–OH, with as little as 13% carbenic character, undergo [1+2] cycloaddition preferentially (B3LYP/6-31+G(d))." @default.
• W181606543 created "2016-06-24" @default.
• W181606543 creator A5012719160 @default.
• W181606543 date "2012-12-10" @default.
• W181606543 modified "2023-09-27" @default.
• W181606543 title "Computational studies on formation and intermolecular [1+2] cycloadditions of nitrilimines" @default.
• W181606543 cites W1501372585 @default.
• W181606543 cites W1504770578 @default.
• W181606543 cites W1548551133 @default.
• W181606543 cites W2768565525 @default.
• W181606543 hasPublicationYear "2012" @default.
• W181606543 type Work @default.
• W181606543 sameAs 181606543 @default.
• W181606543 citedByCount "0" @default.
• W181606543 crossrefType "dissertation" @default.
• W181606543 hasAuthorship W181606543A5012719160 @default.
• W181606543 hasConcept C121332964 @default.
• W181606543 hasConcept C139210041 @default.
• W181606543 hasConcept C147597530 @default.
• W181606543 hasConcept C161790260 @default.
• W181606543 hasConcept C178790620 @default.
• W181606543 hasConcept C184779094 @default.
• W181606543 hasConcept C185592680 @default.
• W181606543 hasConcept C2779012754 @default.
• W181606543 hasConcept C2779664164 @default.
• W181606543 hasConcept C32909587 @default.
• W181606543 hasConcept C46000676 @default.
• W181606543 hasConcept C71240020 @default.
• W181606543 hasConceptScore W181606543C121332964 @default.
• W181606543 hasConceptScore W181606543C139210041 @default.
• W181606543 hasConceptScore W181606543C147597530 @default.
• W181606543 hasConceptScore W181606543C161790260 @default.
• W181606543 hasConceptScore W181606543C178790620 @default.
• W181606543 hasConceptScore W181606543C184779094 @default.
• W181606543 hasConceptScore W181606543C185592680 @default.
• W181606543 hasConceptScore W181606543C2779012754 @default.
• W181606543 hasConceptScore W181606543C2779664164 @default.
• W181606543 hasConceptScore W181606543C32909587 @default.
• W181606543 hasConceptScore W181606543C46000676 @default.
• W181606543 hasConceptScore W181606543C71240020 @default.
• W181606543 hasLocation W1816065431 @default.
• W181606543 hasOpenAccess W181606543 @default.
• W181606543 hasPrimaryLocation W1816065431 @default.
• W181606543 hasRelatedWork W1147865700 @default.
• W181606543 hasRelatedWork W1859046101 @default.
• W181606543 hasRelatedWork W1971232371 @default.
• W181606543 hasRelatedWork W2000914032 @default.
• W181606543 hasRelatedWork W2002855773 @default.
• W181606543 hasRelatedWork W2049818443 @default.
• W181606543 hasRelatedWork W2059777002 @default.
• W181606543 hasRelatedWork W2084377860 @default.
• W181606543 hasRelatedWork W2087004313 @default.
• W181606543 hasRelatedWork W2114571221 @default.
• W181606543 hasRelatedWork W2141784003 @default.
• W181606543 hasRelatedWork W2169679839 @default.
• W181606543 hasRelatedWork W2328811555 @default.
• W181606543 hasRelatedWork W2407454290 @default.
• W181606543 hasRelatedWork W2605464273 @default.
• W181606543 hasRelatedWork W2967846426 @default.
• W181606543 hasRelatedWork W2969344871 @default.
• W181606543 hasRelatedWork W3049647210 @default.
• W181606543 hasRelatedWork W3158702590 @default.
• W181606543 hasRelatedWork W3212613826 @default.
• W181606543 isParatext "false" @default.
• W181606543 isRetracted "false" @default.
• W181606543 magId "181606543" @default.
• W181606543 workType "dissertation" @default.