An efficient synthesis of α,β-unsaturated alkylimines at low temperature using azides has been developed. Carbocations generated from allyl alcohols helped achieve a rapid conversion under mild conditions with azides to afford reactive α,β-unsaturated imines. Hydroxy or alkoxy groups are essential for these transformations, and utilizing readily accessible allyl alcohols gave a wide extension of substrates
Highly Selective Hydrolytic Kinetic Resolution of Terminal Epoxides Catalyzed by Chiral (salen)Co<sup>III</sup> Complexes. Practical Synthesis of Enantioenriched Terminal Epoxides and 1,2-Diols
作者:Scott E. Schaus、Bridget D. Brandes、Jay F. Larrow、Makoto Tokunaga、Karl B. Hansen、Alexandra E. Gould、Michael E. Furrow、Eric N. Jacobsen
DOI:10.1021/ja016737l
日期:2002.2.1
The hydrolytickineticresolution (HKR) of terminal epoxides catalyzed by chiral (salen)Co(III) complex 1 x OAc affords both recovered unreacted epoxide and 1,2-diol product in highly enantioenriched form. As such, the HKR provides general access to useful, highly enantioenriched chiral building blocks that are otherwise difficult to access, from inexpensive racemic materials. The reaction has several
A short and efficient synthesis of 4-hydroxy-5-(1-hydroxyalkyl)-γ-butyrolactones
作者:J.W. Scheeren、J. Lange
DOI:10.1016/s0040-4039(01)90024-3
日期:1984.1
The cycloaddition of α,β-epoxyaldehydes or ketones () with the keteneacetal MeHC=C(OMe)2 () gives epoxyoxetanes () in high yields. Without isolation they can be transformed into 4-hydroxy-5-(1-hydroxyalkyl)-γ-butyrolactones () via the epoxy esters and trihydroxy esters (). The lactones appear to be valuable precursors for the synthesis of 5-(1-hydroxyalkyl)-3-methyl-2-5H-furanones () and 3-methyl-
Epoxidation of terminal or electron-deficient olefins with H2O2, catalysed by Mn-trimethyltriazacyclonane complexes in the presence of an oxalate buffer
作者:Dirk E. De Vos、Bert F. Sels、Mattias Reynaers、Y.V. Subba Rao、Pierre A. Jacobs
DOI:10.1016/s0040-4039(98)00396-7
日期:1998.5
catalytic amount of an oxalate/oxalic acid buffer strongly enhances the catalytic properties of Mn-tmtacn complexes for epoxidation reactions with H2O2. Especially terminalolefins are easily epoxidized. Yields for e.g. allyl acetate or 1-hexene reach up to 99% and 65% on olefin and peroxide basis respectively. The reaction is stereospecific; there are no products of solvolysis.
催化量的草酸盐/草酸缓冲液可大大增强Mn-tmtacn配合物与H 2 O 2进行环氧化反应的催化性能。特别是末端烯烃容易被环氧化。对于产量例如乙酸烯丙基酯或1-己烯分别高达99%和烯烃和过氧化基础65%。该反应是立体特异性的。没有溶剂分解的产物。
Hydrotalcite-promoted epoxidation of electron-deficient alkenes with hydrogen peroxide
A synthetic anionic clay, hydrotalcite (), promotes the epoxidation of electron-deficientalkenes with H2O2. With open-chain, α,β-unsaturated carbonyl compounds 3-hydroxy-1,2-dioxolanes are also obtained.
合成阴离子粘土水滑石()可以促进缺电子烯烃与H 2 O 2的环氧化。用开链,也可得到α,β-不饱和羰基化合物3-羟基-1,2-二氧戊环。