aminolysis of 3,4‐epoxy amines has been achieved. Key features of this reaction are (1) chemoselective activation of epoxides in the presence of unprotected aliphatic amines in the same molecules by a La(OTf)3 catalyst and (2) excellent regioselectivity for anti‐Baldwin 5‐endo‐tet cyclization. This reaction affords 3‐hydroxy‐2‐alkylpyrrolidines stereospecifically in high yields. DFT calculations revealed
Diastereoselective epoxidation of olefins by organo sulfonic peracids, II
作者:R. Kluge、M. Schulz、S. Liebsch
DOI:10.1016/0040-4020(95)01128-5
日期:1996.2
have investigated the behaviour of sulfonic peracids 2in situ generated towards olefins 7a,7b,9,11,14,16,18, allylic and homoallylic alcohols 20,22,24,26,28,30,33 and α,β-unsaturated ketones 35,37,39. Generally, the epoxidation proceeds in a peracid-like manner with greater diastereoselectivity than those by common oxidants. In particular, the epoxidation of Δ4 3-ketosteroids 39a-i led to 4α,5α-epoxides
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.
Tungsten-Catalyzed Asymmetric Epoxidation of Allylic and Homoallylic Alcohols with Hydrogen Peroxide
作者:Chuan Wang、Hisashi Yamamoto
DOI:10.1021/ja411379e
日期:2014.1.29
A simple, efficient, and environmentally friendly asymmetricepoxidation of primary, secondary, tertiary allylic, and homoallylic alcohols has been accomplished. This process was promoted by a tungsten–bishydroxamic acid complex at room temperature with the use of aqueous 30% H2O2 as oxidant, yielding the products in 84–98% ee.
伯、仲、叔烯丙醇和高烯丙醇的简单、高效和环境友好的不对称环氧化已经完成。该过程在室温下由钨-双异羟肟酸配合物促进,使用 30% H2O2水溶液作为氧化剂,产生 84-98% ee 的产物。