enantioselective catalytic kinetic resolution of allylic alcohols through asymmetric isomerization with chiralBINOL derivatives-based alkoxides as bifunctional Brønsted base catalysts were described in the study. A number of chiralBINOL derivatives-based alkoxides were synthesized, and their structure-enantioselectivity correlation study in asymmetric isomerization identified a promising chiral Brønsted
An inexpensive alloy of light lanthanides, called Mischmetall, has been used in the preparation of a mixture of lanthanide trichloride hydrates. The use of this new type of material is described in Luche-type reductions.
A New Route to Diastereomerically Pure Cyclopropanes Utilizing Stabilized Phosphorus Ylides and γ-Hydroxy Enones Derived from 1,2-Dioxines: Mechanistic Investigations and Scope of Reaction
作者:Thomas D. Avery、Dennis K. Taylor、Edward R. T. Tiekink
DOI:10.1021/jo0002240
日期:2000.9.1
setting up the observed cis stereochemistry between H1 and H3. Cyclization of the resultant enolate (30a or 30b), expulsion of triphenylphosphine oxide, and proton transfer from the reaction manifold affords the observed cyclopropanes in excellent diastereomeric excess. The utilization of Co(SALEN)(2) in a catalytic manner also allows for a dramatic acceleration of reaction rates when entering the reaction
FLEMING, I.;KUEHNE, H.;TAKAKI, KEN, J. CHEM. SOC. PERKIN TRANS., 1986, N 4, 725-728
作者:FLEMING, I.、KUEHNE, H.、TAKAKI, KEN
DOI:——
日期:——
A Novel Synthesis of Functionalized Tetrahydrofurans by an Oxa-Michael/Michael Cyclization of γ-Hydroxyenones
作者:Ben W. Greatrex、Marc C. Kimber、Dennis K. Taylor、Edward R. T. Tiekink
DOI:10.1021/jo020700h
日期:2003.5.1
An approach to highly functionalizedtetrahydrofuran derivatives based upon a novel Oxa-Michael/Michael dimerization of cis-gamma-hydroxyenones is presented. The reaction begins with either 1,2-dioxines or trans-gamma-hydroxyenones and proceeds by addition of one molecule of trans-gamma-hydroxyenone to another molecule of cis- or trans-gamma-hydroxyenone catalyzed by an alkoxide or hydroxide base.