Development and application of versatile bis-hydroxamic acids for catalytic asymmetric oxidation
作者:Allan U. Barlan、Wei Zhang、Hisashi Yamamoto
DOI:10.1016/j.tet.2007.03.071
日期:2007.7
preliminary results of our new designed C(2)-symmetric bis-hydroxamic acid (BHA) ligands and the application of the new ligands for vanadium-catalyzed asymmetric epoxidation of allylic alcohols as well as homoallylic alcohols. From this success we demonstrate the versatile nature of BHA in the molybdenum catalyzed asymmetric oxidation of unfunctionalized olefins and sulfides.
Zirconium(IV)- and Hafnium(IV)-Catalyzed Highly Enantioselective Epoxidation of Homoallylic and Bishomoallylic Alcohols
作者:Zhi Li、Hisashi Yamamoto
DOI:10.1021/ja100951u
日期:2010.6.16
enantioselective epoxidation of homoallylic alcohols and bishomoallylic alcohols, which used to be quite difficult substrates for other types of asymmetricepoxidation reactions. The performance of the catalyst was improved by adding polar additive and molecular sieves. For homoallylic alcohols, the reaction could provide epoxy alcohols in up to 83% yield and up to 98% ee, while, for bishomoallylic alcohols, up
Highly Enantioselective and Efficient Asymmetric Epoxidation Catalysts: Inorganic Nanosheets Modified with α-Amino Acids as Ligands
作者:Jiuzhao Wang、Liwei Zhao、Huimin Shi、Jing He
DOI:10.1002/anie.201103713
日期:2011.9.19
Layered catalyst: The attachment of α‐amino acid ligands to inorganic nanosheets for use as ligands to vanadium, resulted in a catalyst that enhanced the enantioselectivity of the epoxidation of allylic alcohols (see picture) . The catalyst can be colloidized, allowing for the catalytic reactions to be carried out under pseudo‐homogeneous reaction conditions and also the catalysts to be directly recycled
Catalytic Enantioselective Epoxidation of Homoallylic Alcohols by Chiral Zirconium Complexes
作者:Takahiro Okachi、Norio Murai、Makoto Onaka
DOI:10.1021/ol027261t
日期:2003.1.1
Catalytic enantioselective epoxidation of homoallylic alcohols using Zr(Ot-Bu)(4) and tartrate ester (or tartramide) has been developed. In the Zr(Ot-Bu)(4)/diisopropyl tartrate-catalyzed epoxidation, the reverse of the enantiofacial preference was observed, depending on the Zr/ligand ratios of 1:1 or 1:2.