Linked Life Data

19653692

Source:http://linkedlifedata.com/resource/pubmed/id/19653692

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
33
pubmed:dateCreated
2009-9-2
pubmed:abstractText
The first catalytic enantioselective conjugate boration of beta-substituted cyclic enones was developed to produce enantiomerically enriched tertiary organoboronates. The optimized asymmetric catalyst includes a QuinoxP*-CuO(t)Bu complex generated from CuPF(6)(CH(3)CN)(4) and LiO(t)Bu. In situ generated LiPF(6) significantly increased product yield. The enantioselectivity, however, was almost constant irrespective of the alkali metal used (Li, Na, or K). Moreover, a protic additive, which was essential in the previous Cu-catalyzed enantioselective boration to linear beta-monosubstituted substrates (Yun's reaction), was not necessary. The substrate scope was broad, and high to excellent enantioselectivity was produced using both beta-aromatic and aliphatic (linear and branched)-substituted cyclic enones with five-, six-, and seven-membered ring sizes. Due to the synthetic versatility of organoboron compounds, a variety of new chiral building blocks containing a chiral tetrasubstituted carbon was synthesized based on this methodology. Specifically, a one-pot three-component reaction from alpha,beta-substituted cyclic enone, bis(pinacolato)diboron (PinB-BPin: 2), and an aldehyde proceeded with a high level of enantio- and diastereocontrol. These chiral building blocks are difficult to access using other methods.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1520-5126
pubmed:author
pubmed:issnType
Electronic
pubmed:day
26
pubmed:volume
131
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11664-5
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Catalytic asymmetric synthesis of chiral tertiary organoboronic esters through conjugate boration of beta-substituted cyclic enones.
pubmed:affiliation
Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo113-0033, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't