| Superacid-catalyzed intramolecular cyclization reaction of arylcyanopropionate: geminal substitution effect on superelectrophilicity. | |
| | |
MedLine Citation:
|
PMID: 18476746 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
We present superacid-catalyzed intramolecular cyclization reactions of arylcyanopropionates to give cyclized five- and six-membered beta-enamino esters in moderate to high yields. Known intramolecular ring-closing reactions of protonated nitrile to aromatic carbon atom are limited to the 6-membered case. Interestingly, a significant synergistic increase of reactivity of the cyano functionality was observed, and the cyano nitrogen atom was converted into an amino group, when an ester group was present in a geminal arrangement. Deuterium exchange experiments excluded the involvement of deprotonation of the alpha-proton in the cyclization process. The acidity dependence of the cyclization reactions and (13)C NMR studies of a model compound, methyl cyanoacetate, in various acidic media were consistent with the involvement of the O, N-diprotonated dication of methyl cyanoacetate, a distonic dication, in strong acid, and this is considered to be the de facto electrophile in the present cyclization reaction of arylcyanopropionates. |
| | |
Authors:
|
Satoshi Nakamura; Hiromichi Sugimoto; Tomohiko Ohwada |
Related Documents
:
|
14565766 - Formation of vinylogous compounds in model maillard reaction systems. 17655256 - Reinvestigating the role of multiple hydrogen transfers in baeyer-villiger reactions. 8349416 - Identification and suppression of decomposition during carbodiimide-mediated reactions ... 17249776 - Selective recognition of tryptophan through inhibition of intramolecular charge-transfe... 11537856 - Collagen in the spicule organic matrix of the gorgonian leptogorgia virgulata. 23606926 - Neurotoxic effects of trans-glutaconic acid in rats. |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2008-05-14 |
Journal Detail:
|
Title: The Journal of organic chemistry Volume: 73 ISSN: 0022-3263 ISO Abbreviation: J. Org. Chem. Publication Date: 2008 Jun |
Date Detail:
|
Created Date: 2008-05-30 Completed Date: 2008-08-21 Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 2985193R Medline TA: J Org Chem Country: United States |
Other Details:
|
Languages: eng Pagination: 4219-24 Citation Subset: IM |
Affiliation:
|
Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Acids
/
chemistry* Catalysis Cyclization Magnetic Resonance Spectroscopy Propionates / chemistry* Spectrometry, Mass, Electrospray Ionization |
| Chemical | |
Reg. No./Substance:
|
0/Acids; 0/Propionates |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Stable ion and electrophilic chemistry of the sterically crowded stilbene 1,1'-Bi(benzocyclobutenyli...
Next Document: Design and synthesis of macrocyclic peptomers as mimics of a quorum sensing signal from Staphylococc...