Document Detail

Superelectrophilic activation of 4-heterocyclohexanones. Implications for polymer synthesis. A theoretical study.
MedLine Citation:
PMID:  18052258     Owner:  NLM     Status:  PubMed-not-MEDLINE    
The stability and the reactivity of mono- and diprotonated 4-heterocyclohexanones as well as cyclohexanone in triflic acid have been studied at the PBE0/aug-cc-pvtz//PBE0/6-31+G** level of theory. In all cases the first protonation is an exergonic process occurring at a carbonyl oxygen except for 4-piperidone where a nitrogen atom is protonated fist. Second protonation is only slightly endergonic for all studied molecules except for cyclohexanone where the second protonation is very unfavorable thermodynamically. According to calculations, diprotonated 4-heterocyclohexanones are much more active in the reactions of triflic acid mediated polyalkoxyalkylation with aromatic hydrocarbons compared to monoprotonated ones. The increase of the reactivity of diprotonated 4-heterocyclohexanones is due to inductive effect rather than through space electrostatic influence as follows from the electronic structure analysis of dications. Moreover, the second protonation reduces the possibility of an aldol condensation side reaction, reducing the enol electrophilicity rendering heterocyclohexanones as promising monomers for superacid mediated polyhydroxyalkylation.
Alfredo Lopez Lira; Mikhail Zolotukhin; Lioudmila Fomina; Serguei Fomine
Related Documents :
21671328 - Sesam-tv-ii generates a protein sequence space that is unobtainable by eppcr.
6441568 - Cross-linking of histones with dimethyl 3,3'-dithiobispropionimidate. interference by a...
18293348 - Heteropoly acid encapsulated sba-15/tio2 nanocomposites and their unusual performance i...
16168698 - Single bubble sonochemistry: decomposition of alkyl bromide and the isomerization react...
1636418 - Permeability of arachidonic acid metabolites through the round window membrane in chinc...
19327988 - 1-(5-carboxyindol-1-yl)propan-2-ones as inhibitors of human cytosolic phospholipase a2a...
Publication Detail:
Type:  Journal Article     Date:  2007-12-05
Journal Detail:
Title:  The journal of physical chemistry. A     Volume:  111     ISSN:  1089-5639     ISO Abbreviation:  J Phys Chem A     Publication Date:  2007 Dec 
Date Detail:
Created Date:  2007-12-20     Completed Date:  2008-03-06     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9890903     Medline TA:  J Phys Chem A     Country:  United States    
Other Details:
Languages:  eng     Pagination:  13606-10     Citation Subset:  -    
Instituto de Investigaciones en Materiales Universidad Nacional Autonoma de Mexico, Apartado Postal 70-360, CU, Coyoacan, Mexico DF 04510, México.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  One-electron oxidation and reduction potentials of nitroxide antioxidants: a theoretical study.
Next Document:  Multiple bonds and excited states from the Hartree-Fock-Heitler-London method.