亲核试剂引发的巯基丙烯酸酯反应的普遍接受的机制要求形成不期望的亲核试剂副产物。已经对这类亲核试剂副产物的形成进行了系统评价,以了解副产物形成与亲核试剂结构,化学计量,溶剂和反应类型之间的关系。研究了硫醇-迈克尔反应的三种常见亲核试剂:二甲基苯基膦(DMPP),二乙胺(DEA)和己胺(HA)。在引发剂负载量(0.01-10.0当量)和不同溶剂(纯溶剂,DMSO,THF和CHCl)中,在1-己硫醇和丙烯酸甲酯之间引发代表性的硫醇-丙烯酸酯反应时,形成ester酯和氮杂-Michael副产物3)由1确定1 H NMR光谱。通过从小分子反应扩展到PEG-二丙烯酸酯聚合物的端基巯基丙烯酸酯官能化以及对聚合物-聚合物偶联反应的研究,研究了反应类型的影响。结果表明,亲核试剂副产物形成的倾向随亲核试剂类型,溶剂和反应类型的不同而不同。有趣的是,对于除聚合物-聚合物连接反应以外的所有反应,亲核副产物的形成在
Convenient One-Pot Synthesis of β-Alkylthio Acid Derivatives from Thioacetates and the Corresponding α,β-Unsaturated Compounds
作者:Dong Won Lee、Jaesung Choi、Nung Min Yoon
DOI:10.1080/00397919608003578
日期:1996.6
Various β-alkylthio acid derivatives were prepared conveniently from thioacetates and α,β-unsaturated compounds through borohydride exchange resin (BER)-Pd catalyzed transesterification of thioacetates to the corresponding thiols and Michael addition of the resulting thiols to α,β-unsaturated compounds.
Pentaerythritol co-esters derived from pentaerythritol, (3-alkyl-4-hydroxyphenyl)-alkanoic acids or an analog thereof and alkylthioalkanoic acids or lower alkyl esters of such acids are useful as stabilizers of organic material normally susceptible to oxidative and/or thermal deterioration. The co-esters are advantageously prepared by transesterification of such esters with pentaerythritol. Preferred co-esters are (I) pentaerythritol tris[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]-mono[3-n-dodecylthiopropionate] and (II) pentaerythritol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]-bis[3-n-dodecylthiopropionate). The co-esters are especially useful in stabilizing applications for which physical mixtures of (i) (3-alkyl-4-hydroxyphenyl)alkanoic acid esters of polyols with (ii) polyalkanol esters of alkylthioalkanoic acids have heretofore been proposed.
由季戊四醇、(3-烷基-4-羟基苯基)-烷酸或其类似物以及烷硫基烷酸或此类酸的低级烷基酯衍生的季戊四醇共酯可用作通常易受氧化和/或热变质影响的有机材料的稳定剂。共酯的制备方法主要是将此类酯与季戊四醇进行酯交换反应。优选的共酯类有:(I) 季戊四醇三[3-(3,5-二叔丁基-4-羟基苯基)丙酸酯]-单[3-正十二烷基硫代丙酸酯]和 (II) 季戊四醇双[3-(3,5-二叔丁基-4-羟基苯基)丙酸酯]-双[3-正十二烷基硫代丙酸酯]。这些共酯在稳定应用方面特别有用,此前已经提出了 (i) (3- 烷基-4-羟基苯基)烷酸多元醇酯与 (ii) 烷硫基烷酸多元醇酯的物理混合物。
Poly(N-vinylimidazole) as efficient and recyclable catalyst for the addition of thiols to michael acceptors in aqueous medium
作者:I. P. Beletskaya、E. A. Tarasenko、A. R. Khokhlov、V. S. Tyurin