Linked Life Data

14535768

Source:http://linkedlifedata.com/resource/pubmed/id/14535768

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2003-10-10
pubmed:abstractText
UV-vis spectra of the dilithium, 1-Li, and dicesium, 1-Cs, enediolates of alpha-naphthylacetic acid show no systematic change with concentration in dilute THF solution, but addition of small amounts of HMPA causes a bathochromic shift in the spectrum of 1-Li. These results indicate that these salts are aggregated and that HMPA breaks up the aggregates of 1-Li. The quantitative effect of small increments of HMPA indicates that 1-Li is a dimer. Alkylation reactions of 1-Cs show half-order kinetics in enediolate indicating that this salt is also dimeric but that the small amount of monomer in equilibrium is the actual reactant. Alkylation of 1-Li, however, is much slower and shows first-order kinetics interpreted as a direct reaction of the dimer; the amount of monomer in this case is too small to compete. A solution of 1-Li in THF containing 10% HMPA is much more reactive in alkylation than 1-Li alone and the first-order dependence in 1-Li is now interpreted as reaction of the monomer. Compound 1-Li is found to form a mixed aggregate with LDA, a finding that has possible synthetic significance since enediolates used in syntheses are frequently prepared using LDA. Structures of these compounds are suggested based on model ab initio computations.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-3263
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
68
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7937-42
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Aggregation and reactivity of the dilithium and dicesium enediolates of 1-naphthylacetic acid.
pubmed:affiliation
Department of Chemistry, University of California, Berkeley, CA 94720-1460, USA. astreit@socrates.berkeley.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.