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
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.
Asymmetric Epoxidation of Homoallylic Alcohols and Application in a Concise Total Synthesis of (−)-α-Bisabolol and (−)-8-epi-α-Bisabolol