Sulphonic acid functionalized porphyrin anchored with a <i>meso</i>-substituted triazolium ionic liquid moiety: a heterogeneous photo-catalyst for metal/base free C–C cross-coupling and C–N/C–H activation using aryl chloride under visible light irradiation
is an efficient photocatalyst for the Heck, Sonogashira, Buchwald, Ullmann/Fittig coupling and C–H activation of phenols with different aryl chlorides in the absence of a base/noble metal, using 5 W LED (yellow) light under ambient conditions. The photocatalyst with low band gap (1.55 eV) comprising conjugation, favors couplingreaction of unactivated aryl chlorides, by easy excitation of electrons
我们报告了一种简单的合成磺酸官能化卟啉的方法,该方法与内消旋的三唑鎓离子液体部分(SAFPTILM)固定,可在可见光下使用芳基氯进行金属/碱自由的C-C交叉偶联和C-N / C-H活化光照射。酸强度已经基于哈米特指示剂进行了测量。SAFPTILM光催化剂包含18个π共轭电子体系,内消旋有生色团取代基位置可以在可见光的照射下的光催化过程中提供快速的电子传导通道。研究发现,使用5 W LED(黄色)光时,SAFPTILM是在没有碱金属/贵金属的情况下,用于Heck,Sonogashira,Buchwald,Ullmann / Fittig偶联和苯酚与不同的芳基氯化物的C–H活化的有效光催化剂。在环境条件下。具有低带隙(1.55 eV)的光催化剂具有共轭作用,通过易于激发电子并转移至基于共轭苯并咪唑鎓的苯二胺载体上,有利于未活化的芳基氯的偶联反应,从而延迟了光致电子-空穴对的重组。
Synthesis of pyrazine-bridged diimidazolium salts and their application in palladium catalyzed Heck-type coupling reactions
作者:Mareike C. Jahnke、Mukhtiar Hussain、Florian Hupka、Tania Pape、Saqib Ali、F. Ekkehardt Hahn、Kingsley J. Cavell
DOI:10.1016/j.tet.2008.11.008
日期:2009.1
Reaction of imidazole derivatives with 2,3-di(bromomethyl)pyrazine results in the formation of the new pyrazine-bridged diimidazolium salts 1–8. These salts proved to be valuable precursors for dinuclear complexes with mixed NHC/pyrazine ligands. Two of the pyrazine-bridged diimidazolium salts 3·H2O and 8·2H2O have been characterized by X-ray diffraction. Furthermore, the first catalytic studies with
An Annelated Mesoionic Carbene (MIC) Based Ru(II) Catalyst for Chemo- and Stereoselective Semihydrogenation of Internal and Terminal Alkynes
作者:Suman Yadav、Indranil Dutta、Sayantani Saha、Shubhajit Das、Swapan K. Pati、Joyanta Choudhury、Jitendra K. Bera
DOI:10.1021/acs.organomet.0c00413
日期:2020.9.14
render the Ru center electron deficient and thus the formation of metal vinylidenes with terminalalkynes is avoided. This is leveraged for the semihydrogenation of terminalalkynes by the same catalytic system in isopropyl alcohol. Reaction profile, isomerization, kinetic, and DFT studies reveal initial alkyne hydrogenation to a (Z)-alkene, which further isomerizes to an (E)-alkene via metal-catalyzed
评估[RuL 1(CO)2 I 2 ](1)的催化效用,该催化剂包含基于π-共轭咪唑-萘啶基的中性离子卡宾(MIC)配体(L 1),用于E-选择性炔烃半氢化反应。预催化剂1与2当量的AgBAr F组合,可在水中与分子氢(5 bar)半氢化各种内部炔烃。(E)-烯烃的收率很高,并且可以容忍许多可还原的官能团。螯合MIC配体和两个顺式羰基在Ru中心为氢化和异构化提供了一个明确的平台。两种碘化物的损失和两种羰基的存在使Ru中心电子缺乏,因此避免了与末端炔烃形成金属亚乙烯基。通过在异丙醇中的相同催化系统,可以利用它来催化末端炔烃的半氢化反应。反应曲线,异构化,动力学和DFT研究表明,最初的炔烃氢化为(Z)烯烃,然后通过金属催化的Z → E异构化进一步异构化为(E)烯烃。
Semireduction of Alkynes Using Formic Acid with Reusable Pd-Catalysts
The treatment of PdCl2 with K2CO3 and HCO2H in dioxane gives black precipitates, which are an effective catalyst for the semireduction of alkynes to alkenes using formicacid as a reductant. Even 0.05 mol % Pd promoted the reduction reaction of tolane in high yield with high selectivity.
在二恶烷中用K 2 CO 3和HCO 2 H处理PdCl 2产生黑色沉淀,这是使用甲酸作为还原剂将炔烃半还原为烯烃的有效催化剂。甚至0.05mol%的Pd也以高收率和高选择性促进了甲苯的还原反应。
First use of a palladium complex with a thiosemicarbazone ligand as catalyst precursor for the Heck reaction
作者:Dimitra Kovala-Demertzi、Paras N. Yadav、Mavroudis A. Demertzis、Jerry P. Jasiski、Fotini J. Andreadaki、Ioannis D. Kostas
DOI:10.1016/j.tetlet.2004.02.062
日期:2004.3
A novel palladium complex with salicylaldehyde N(4)-ethylthiosemicarbazone has been synthesized and according to its crystal structure the ligand is bound to the metal in an O, N, S-terdentate coordinationmode. This phosphorus-free system efficiently catalyzes the Heckreaction of aryl bromides (from electron-rich to electron-poor) with styrene under argon, with turnover numbers of up to 43,000, at