Linked Life Data

15250731

Source:http://linkedlifedata.com/resource/pubmed/id/15250731

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
28
pubmed:dateCreated
2004-7-14
pubmed:abstractText
Full details of a direct catalytic asymmetric Mannich-type reaction of a hydroxyketone using a Et2Zn/(S,S)-linked-BINOL complex are described. By choosing the proper protective groups on imine nitrogen, either anti- or syn-beta-amino alcohol was obtained in good diastereomeric ratio, yield, and excellent enantiomeric excess using the same zinc catalysis. N-Diphenylphosphinoyl (Dpp) imine 3 gave anti-beta-amino alcohols in anti/syn = up to >98/2, up to >99% yield, and up to >99.5% ee, while Boc-imine 4 gave syn-beta-amino alcohols in anti/syn = up to 5/95, up to >99% yield, and up to >99.5% ee. The high catalyst turnover number (TON) is also noteworthy. Catalyst loading was successfully reduced to 0.02 mol % (TON = up to 4920) for the anti-selective reaction and 0.05 mol % (TON = up to 1760) for the syn-selective reaction. The Et2Zn/(S,S)-linked-BINOL complex exhibited far better TON than in previous reports of catalytic asymmetric Mannich-type reactions. Mechanistic studies to clarify the reason for the high catalyst efficiency as well as transformations of Mannich adducts are also described.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0002-7863
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
126
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8777-85
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Direct catalytic asymmetric Mannich-type reaction of hydroxyketone using a Et2Zn/linked-BINOL complex: synthesis of either anti- or syn-beta-amino alcohols.
pubmed:affiliation
Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't