Linked Life Data

20175165

Source:http://linkedlifedata.com/resource/pubmed/id/20175165

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2010-3-24
pubmed:abstractText
A direct catalytic asymmetric aldol-type reaction of 3-substituted-2-oxindoles with glyoxal derivatives and ethyl trifluoropyruvate, catalyzed by a chiral N,N'-dioxide-Sc(OTf)(3) (Tf = trifluoromethanesulfonyl) complex, has been developed that tolerates a wide range of substrates. The reaction proceeds in good yields and excellent enantioselectivities (up to 93% yield, 99:1 diastereomeric ratio (dr), and >99% enantiomeric excess (ee)) under mild conditions, to deliver 3-(alpha-hydroxy-beta-carbonyl) oxindoles with vicinal quaternary-tertiary or quaternary-quaternary stereocenters. Even with 1 mol % catalyst loading or on scaleup (10 mmol of starting material), maintenance of ee was observed, which showed the potential value of the catalyst system. In studies probing the reaction mechanism, a positive nonlinear effect was observed and Sc(III)-based enolate intermediates were detected by using ESIMS. On the basis of the experimental results and previous reports, a possible catalytic cycle was assumed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1521-3765
pubmed:author
pubmed:issnType
Electronic
pubmed:day
22
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3736-42
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Catalytic asymmetric synthesis of 3-(alpha-hydroxy-beta-carbonyl) oxindoles by a Sc(III)-catalyzed direct aldol-type reaction.
pubmed:affiliation
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, PR China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't