Novel multi-dentate phosphines for Pd-catalyzed alkoxycarbonylation of alkynes promoted by H2O additive
作者:Da Yang、Lei Liu、Dong-Liang Wang、Yong Lu、Xiao-Li Zhao、Ye Liu
DOI:10.1016/j.jcat.2019.01.031
日期:2019.3
A series of novel multi (bi-/tri-/tetra-)-dentate phosphines with good robustness against water and oxygen were synthesized and fully characterized. It was found that the developed ionic tri-dentate phosphine (L2′) enabled Pd-catalyzed alkoxycarbonylation of alkynes most efficiently while H2O was used as an additive instead of acid. As for L2′, its unique steric configuration with two types of potential
several pinacol or neopentylglycol boronates indicated further potential of the catalyst. The reaction conditions tolerate the hydroxyl and bromo functional groups. The catalytic system also enables to synthesize the mono-N-substituted anilines from primary aliphatic amines. However, the two model compounds for the secondary and aromatic amines, piperidine and aniline, do not react. Two sterically demanding
基于Chan-Lam交叉偶联反应,开发了一种基于使用稳定铜(I)源的现成Cu 2 S / TMEDA系统的催化剂。用1 H-苯并[ d ]咪唑-2(3 H)-1,1 H-苯并[ d ]咪唑和1 H-咪唑以及缺电子,富电子和在室温下,在大气氧的存在下,对空间需求量高的硼酸,以中等至极好的收率得到交叉偶联的产物。另外,1 H-苯并[ d]的偶联反应]咪唑与几种频哪醇或新戊二醇硼酸酯表明该催化剂的进一步潜力。反应条件容许羟基和溴官能团。该催化体系还能够由伯脂族胺合成单-N-取代的苯胺。但是,仲胺和芳族胺的两种模型化合物哌啶和苯胺不会反应。两个空间要求的产品与受限Ç N键的旋转,通过将合成的Ñ 1的-arylation ħ -苯并[ d ]咪唑-2(3 H ^) -酮与ö-甲苯磺酸,能够确认由Chan-Lam交叉偶联反应制得的阻转异构体。此外,已经报道了一锅Chan-Lam和Suzuki-Miyaura反应的例子。
<i>N</i>-Arylation of (hetero)arylamines using aryl sulfamates and carbamates <i>via</i> C–O bond activation enabled by a reusable and durable nickel(0) catalyst
elemental analysis techniques. The reaction proceeded via carbon–oxygen bondcleavage of (hetero)aryl carbamates and sulfamates under simple and mild conditions without the use of any external ligands. This method demonstrated functional group tolerance in the N-arylation of various nitrogen-containing compounds as well as aliphatic amines, anilines, pyrroles, pyrazoles, imidazoles, indoles, and indazoles
已经开发出了一种有效且通用的芳基胺化方案,使用了可磁回收的Ni(0)基纳米催化剂。该新型稳定催化剂是在EDTA改性的Fe 3 O 4 @SiO 2上制备的,并通过FT-IR,EDX,TEM,XRD,DLS,FE-SEM,XPS,NMR,TGA,VSM,ICP和元素分析技术进行了研究。该反应通过在简单温和的条件下不使用任何外部配体的情况下,通过(杂)芳基氨基甲酸酯和氨基磺酸酯的碳-氧键裂解来进行。该方法证明了N中的官能团耐受性各种含氮化合物以及脂肪族胺,苯胺,吡咯,吡唑,咪唑,吲哚和吲唑的芳基化,收率良好。此外,该催化剂可以通过使用外部磁场容易地回收,并且可以直接重复使用至少六次而不会显着降低其活性。
Salen complex of Cu(II) supported on superparamagnetic Fe3O4@SiO2 nanoparticles: an efficient and magnetically recoverable catalyst for N-arylation of imidazole with aryl halides
economical, and magnetically recoverable heterogeneouscatalyst for the selective and efficient N-(hetero)arylation of imidazole. Only by adding a small amount of the catalyst (0.4 mol% Cu) to the reactants and heating under air, the new presented method provides a variety of functionalized and hindered N-(hetero)arylimidazoles in good to excellent yields within short reaction times. The catalyst could be
摘要据报道,Fe 3 O 4 @SiO 2 / Salen-Cu(II)纳米催化剂是一种热和空气稳定,经济,可磁回收的非均相催化剂,用于咪唑的选择性和有效的N-(杂)芳基化。仅通过向反应物中添加少量催化剂(0.4 mol%Cu)并在空气中加热,新提出的方法即可提供多种功能化和受阻的氮-(杂)芳基咪唑在较短的反应时间内即可获得良好至极好的收率。借助永磁体可以很容易地回收催化剂,并且可以连续使用多达五次而又不会明显丧失活性。而且,在第五次循环之后,铜的浸出量可以忽略不计。特别地,使用(杂)芳基碘化物或溴化物作为芳基化剂,并且仅需要少量的可磁回收的非均相铜基纳米催化剂使该方法低成本,对环境无害且易于使用。 图形概要