Linked Life Data

11506227

Source:http://linkedlifedata.com/resource/pubmed/id/11506227

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2001-8-16
pubmed:abstractText
We report gas phase ion/molecule reactions between dialkoxyborinium cations (RO-B+-OR) and small organic amides, such as N,N-dimethylformamide and N,N-diethylpropionamide. Besides direct addition at boron, the results show efficient SN2 methyl transfer from the borinium ion to the amide. Isotopic labeling and collision-induced dissociation (CID) of the methyl transfer products demonstrate O-methylation of the amide. Methyl substitution at the alpha-carbon of the amide affects the degree of alkylation and adduct formation. Direct proton abstraction via beta-elimination is a major competitive reaction for substituents other than methyl. Ab initio calculations at the B3LYP/6-31G(d) level indicate that SN2 transmethylation is highly exothermic with O-methylation favored over N-methylation by 14.8 kcal/mol.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Aug
pubmed:issn
1044-0305
pubmed:author
pubmed:issnType
Print
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
948-55
pubmed:dateRevised
2003-10-31
pubmed:year
2001
pubmed:articleTitle
Gas-phase SN2 reactivity of dicoordinated borinium cations using pentaquadrupole mass spectrometry.
pubmed:affiliation
Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-1393, USA.
pubmed:publicationType
Journal Article