A Diacetate Ketone-Catalyzed Asymmetric Epoxidation of Olefins
作者:Bin Wang、Xin-Yan Wu、O. Andrea Wong、Brian Nettles、Mei-Xin Zhao、Dajun Chen、Yian Shi
DOI:10.1021/jo900330n
日期:2009.5.15
A fructose-derived diacetate ketone has been shown to be an effective catalyst for asymmetricepoxidation. High ee values have been obtained for a variety of trans and trisubstituted olefins including electron-deficient α,β-unsaturated esters as well as certain cis olefins.
果糖衍生的二乙酸酮已被证明是不对称环氧化的有效催化剂。各种反式和三取代烯烃(包括缺电子 α,β-不饱和酯以及某些顺式烯烃)都获得了高 ee 值。
Catalytic asymmetric epoxidation
申请人:——
公开号:US06348608B1
公开(公告)日:2002-02-19
A compound and method for producing an enantiomerically enriched epoxide from an olefin using a chiral ketone and an oxidizing agent is disclosed.
一种化合物及其生产方法被披露,该方法使用手性酮和氧化剂从烯烃生产具有对映体富集的环氧乙烷。
Exploring Substrate Scope of
Shi-Type Epoxidations
Enantioselective epoxidations of alkenes (12 examples) were achieved using a Shi-type carbohydrate-derived hydrate and Oxone. The chiral platform provided by the catalyst tolerates a wide range of substituents providing high yields and enantioselectivities (80-95.5% ee). However, styrene derivatives were only converted with poor selectivities (11-26% ee).
Catalytic asymmetric epoxidation of alkenes with arabinose-derived uloses
作者:Tony K.M Shing、Yiu C Leung、Kwan W Yeung
DOI:10.1016/s0040-4020(03)00145-5
日期:2003.3
Four l-erythro-2-uloses were readily prepared from l-arabinose via a reaction sequenceinvolving Fischer glycosidation, acetalization and oxidation. Bulky steric sensors at the anomeric center could enhance the stereoselectivity of the dioxirane epoxidation and one of the uloses performed with good enantioselectivity towards trans-stilbene (up to 90% ee). However, the catalysts decomposed during the
Arabinose-Derived Ketones as Catalysts for Asymmetric Epoxidation of Alkenes
作者:Tony K. M. Shing、Gulice Y. C. Leung、To Luk
DOI:10.1021/jo050928f
日期:2005.9.1
Readily available arabinose-derived ketones, containing a tunable butane-2,3-diacetal as the steric blocker, displayed increasing enantioselectivity (up to 90% ee) with the size of the acetal alkyl group in catalytic asymmetricepoxidation of trans-disubstituted and trisubstituted alkenes. The stereochemical communication between our ketonecatalysts and the alkene substrates is mainly due to steric