Synthesis of Substituted 1<i>H</i>,5-Dihydroimidazolium Salts by Dehydrogenation of Imidazolidines
作者:Alejandra Salerno、Cristina Caterina、Isabel A. Perillo
DOI:10.1080/00397910008086977
日期:2000.9
Abstract A study is presented on the scope of the method to obtain 1H-4,5-dihydroimidazolium salts 3 by dehydrogenation of 1,3-di and 1,2,3-trisubstituted imidazolidines 2. Of the dehydrogenating agents used, N-bromoacetamide leads to the best results, providing a simple and general method to prepare salts 3.
Reductive Coupling of Nitroarenes and HCHO for General Synthesis of Functional Ethane-1,2-diamines by a Cobalt Single-Atom Catalyst
作者:Jia-Lu Sun、Huanfeng Jiang、Pierre H. Dixneuf、Min Zhang
DOI:10.1021/jacs.3c04857
日期:2023.8.9
access to N,N′-diarylethane-1,2-diamines remains, to date, a challenge. Here, by developing a bifunctional cobalt single-atom catalyst (CoSA-N/NC), we present a general method for direct synthesis of such compounds via selective reductive coupling of cheap and abundant nitroarenes and formaldehyde, featuring good substrate and functionality compatibility, an easily accessible base metal catalyst with
尽管应用广泛,但迄今为止,选择性和多样化地获取N,N'-二芳基乙烷-1,2-二胺仍然是一个挑战。在这里,通过开发一种双功能钴单原子催化剂(Co SA -N/NC),我们提出了一种通过廉价且丰富的硝基芳烃和甲醛的选择性还原偶联直接合成此类化合物的通用方法,具有良好的底物和功能相容性,一种易于获得的贱金属催化剂,具有出色的可重复使用性以及高步骤效率和原子效率。机理研究表明,N锚定的钴单原子(CoN 4)作为还原过程的催化活性位点,N掺杂的碳载体富集了HCHO,及时捕获了原位形成的羟胺,并在弱电条件下提供了所需的硝酮。碱性条件下,随后硝酮和亚胺的逆电子需求1,3-偶极环加成反应,随后环加合物的加氢脱氧反应提供产物。在这项工作中,催化剂控制的硝基芳烃还原原位产生特定结构单元的概念预计将开发出更有用的化学转化。
High-Throughput Approach in the Ring-Opening Polymerization of β-Butyrolactone Enables Rapid Evaluation of Yttrium Salan Catalysts
Poly(3-hydroxybutyrate) (PHB) is a material produced naturally by bacteria but is also chemically accessible via ring-openingpolymerization (ROP) of β-butyrolactone (β-BL). In ROP, catalyst design plays a key role in the production of PHB with different stereomicrostructures, i.e., syndiotactic, isotactic, or atactic PHB. In this work, we demonstrate a simple procedure for generating the catalysts
聚(3-羟基丁酸酯)(PHB) 是一种由细菌自然产生的材料,但也可以通过 β-丁内酯 (β-BL) 的开环聚合 (ROP) 化学获得。在 ROP 中,催化剂设计在生产具有不同立构微观结构(即间规、等规或无规 PHB)的 PHB 中起着关键作用。在这项工作中,我们展示了一个简单的程序,通过将合适的钇前体与相应的 salan 前配体方便地结合起来,就地生成催化剂。这种方法避免了催化剂的精细分离,并能够高通量筛选用于 β-BL ROP 的钇 salan 催化剂库。可以确定配体框架对催化剂的立体选择性和活性的电子和空间影响以及限制,并建立了结构-性质关系。根据取代模式,这些原位生成的催化剂产生了具有高活性的间规富集、全同立构富集或无规立构 PHB。
B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>-Catalyzed Formal (<i>n</i> + 3) (<i>n</i> = 5 and 6) Cycloaddition of Bicyclo[1.1.0]butanes to Medium Bicyclo[<i>n</i>.1.1]alkanes
Herein, a B(C6F5)3-catalyzed formal (n + 3) (n = 5 and 6) cycloaddition of bicyclo[1.1.0]butanes (BCBs) with imidazolidines/hexahydropyrimidines is described. The reaction provides a modular, atom-economical, and efficient strategy to two libraries of synthetically challenging medium-bridged rings, 2,5-diazabicyclo[5.1.1]nonanes and 2,6-diazabicyclo[6.1.1]decanes, in moderate to excellent yields. This
本文描述了双环[1.1.0]丁烷(BCB)与咪唑烷/六氢嘧啶的B(C 6 F 5 ) 3催化的缩甲醛( n +3)( n =5和6)环加成。该反应为合成具有挑战性的中等桥环库(2,5-二氮杂双环[5.1.1]壬烷和2,6-二氮杂双环[6.1.1]癸烷)提供了一种模块化、原子经济且高效的策略,反应速度适中。达到优异的产量。该反应还具有操作简单、反应条件温和、底物范围广泛等特点。放大实验和产品的各种合成转化进一步凸显了合成实用性。
Process for the dimerization of ethylenically unsaturated compounds
申请人:SHELL INTERNATIONALE RESEARCH
MAATSCHAPPIJ B.V.
公开号:EP0206367A2
公开(公告)日:1986-12-30
The dimerization of acrylate esters and of ethene and the codimerization of acrylate esters with C2-4-alkenes or 1,3-butadiene and of 1,3-butadiene with ethene in the presence of:
(a) a Pd and/or Ru compound,
(b) a compound containing one trivalent N or P atom, and
(c) an Ag and/or Cu salt, yields at an increased reaction rate dimers of high linearity, when a quinone is also present.
丙烯酸酯和乙烯的二聚化,以及丙烯酸酯与 C2-4- 烷烃或 1,3-丁二烯和 1,3-丁二烯与乙烯在下列物质存在下的共聚化:
(a) Pd 和/或 Ru 化合物、
(b) 含一个三价 N 原子或 P 原子的化合物,以及
(c) Ag 和/或 Cu 盐,在同时存在醌的情况下,以更高的反应速率生成线性度更高的二聚 物。