Linked Life Data

20039606

Source:http://linkedlifedata.com/resource/pubmed/id/20039606

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2010-1-29
pubmed:abstractText
A systematic investigation of the reductive ring-expansion reaction of cyclic ketoximes fused to aromatic rings with diisobutylaluminum hydride (DIBALH) is described. This reaction regioselectively afforded a variety of five- to eight-membered bicyclic heterocycles or tricyclic heterocycles containing nitrogen neighboring an aromatic ring, including indoline, 1,2,3,4,5,6-hexahydrobenz[b]azocine, 3,4-dihydro-2H-benzo[b][1,4]oxazine, 2,3,4,5-tetrahydrobenzo[b][1,4]thiazepine, 1,2,3,4,5,6-hexahydroazepino[3,2-b]indole, 2,3,4,5-tetrahydro-1H-benzothieno[2,3-b]azepine, 2,3,4,5-tetrahydro-1H-benzothieno[3,2-b]azepine, 5,6-dihydrophenanthridine, and 5,6,11,12-tetrahydrodibenz[b, f]azocine. The reaction mechanism leading to the rearrangement was investigated on the basis of the restricted Becke three-parameter plus Lee-Yang-Parr (B3LYP) density functional theory (DFT) with the 6-31G (d) basis set. It was found that the reaction proceeds through a three-centered transition state via a stepwise mechanism because the potential energy curve along the intrinsic reaction coordinate (IRC) had two maxima (saddle points; TS1 and TS2) and the partial phenonium cation intermediate C. In addition to cyclic ketoximes fused to aromatic rings, the reactions of various cyclic and acyclic ketoximes were examined to investigate preference of migrating group. It was found that the more electron-rich group migrated preferentially to give the corresponding secondary amines.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1520-6904
pubmed:author
pubmed:issnType
Electronic
pubmed:day
5
pubmed:volume
75
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
627-36
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Regioselective synthesis of heterocycles containing nitrogen neighboring an aromatic ring by reductive ring expansion using diisobutylaluminum hydride and studies on the reaction mechanism.
pubmed:affiliation
Graduate School of Science, Tohoku University,6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan. hcho@mail.pharm.tohoku.ac.jp
pubmed:publicationType
Journal Article