开发用于环境友好的有机转化的催化剂是一个非常活跃的研究领域。迄今为止报道的大多数催化剂都是基于过渡金属配合物。近年来,已经报道了由主族金属化合物催化的例子。在此,我们报告了一系列镁钳配合物,并通过 NMR 和 X 射线单晶衍射对其进行了表征。研究了通过芳构化/脱芳构化金属-配体合作对 H 2的可逆活化。利用所获得的配合物,在无碱条件下证明了前所未有的均相主族金属催化炔烃的半氢化和烯烃的氢化,得到Z-烯烃和烷烃分别作为产物,具有优异的收率和选择性。对照实验和 DFT 研究揭示了金属-配体合作参与氢化反应。该研究不仅为镁催化的炔烃半加氢和烯烃加氢提供了新途径,而且为主族金属配合物催化的其他化合物加氢提供了机会。
Cross-Coupling of Alkynylsilanols with Aryl Halides Promoted by Potassium Trimethylsilanolate
摘要:
The palladium-catalyzed cross-coupling of aliphatic alkynylsilanols with aryl iodides has been demonstrated with potassium trimethylsilanolate as the coupling promoter and copper(I) iodide as a cocatalyst. The cross-coupling proceeds at room temperature in good to excellent yield with a range of aryl iodides. A comparison of the reactivity of alkynylsilanols, trimethylsilylalkynes, and terminal alkynes under fluoride and fluoride-free conditions was per-formed to elucidate the role of silicon in the Sonogashira reaction.
Copper-catalysed photoinduced decarboxylative alkynylation: a combined experimental and computational study
作者:Yu Mao、Wenxuan Zhao、Shuo Lu、Lei Yu、Yi Wang、Yong Liang、Shengyang Ni、Yi Pan
DOI:10.1039/d0sc02213f
日期:——
Redox-active esters (RAEs) as alkyl radical precursors have demonstrated great advantages for C–C bond formation. A decarboxylative cross-coupling method is described to afford substituted alkynes from various carboxylic acids using copper catalysts CuCl and Cu(acac)2. The photoexcitation of copper acetylides with electron-rich NEt3 as a ligand provides a general strategy to generate a range of alkyl
The copper-catalyzeddecarboxylative reactions of alkynyl carboxylic acids with aryl halides were performed under relatively mild reaction conditions. Benzofurans could be further prepared smoothly by a one-pot domino protocol on the basis of decarboxylativecross-coupling of 2-iodophenol.
as a powerful strategy for organometallic catalysis, and yet electrocatalytic C−Hactivation is restricted to strongly N‐coordinating directing groups. The first example of electrocatalytic C−Hactivation by weak O‐coordination is presented, in which a versatileruthenium(II) carboxylate catalyst enables electrooxidative C−H/O−H functionalization for alkyne annulations in the absence of metal oxidants;
电催化已被认为是有机金属催化的有力策略,但是电催化CH活化仅限于强N配位的导向基团。给出了通过弱O配位进行电催化C-H活化的第一个例子,其中通用的羧酸钌(II)催化剂可在没有金属氧化剂的情况下实现炔烃环化的电氧化C / H / OH功能化。从而利用可持续的电力作为唯一的氧化剂。机械学的见解为简便的有机金属CH钌钌化和关键钌(0)中间体的有效电化学再氧化提供了有力的支持。
Palladium-Catalyzed Decarboxylative Coupling of Alkynyl Carboxylic Acids and Aryl Halides
作者:Jeongju Moon、Mihee Jang、Sunwoo Lee
DOI:10.1021/jo802290r
日期:2009.2.6
2-Octynoic acid and phenylpropiolic acid were employed for the palladium-catalyzed decarboxylative coupling reaction and with a variety of arylhalides. The former needed 1,4-bis(diphenylphosphino)butane (dppb) as a ligand and the latter tri-tert-butylphosphine (PtBu3), and both required 2 equiv of tetra-n-butylammonium fluoride (TBAF) for full conversion. These reactions showed high reactivities and
Highly effective copper-catalyzed decarboxylative coupling of aryl halides with alkynyl carboxylic acids
作者:Xiaoming Qu、Tingyi Li、Peng Sun、Yan Zhu、Hailong Yang、Jincheng Mao
DOI:10.1039/c1ob05969f
日期:——
We have developed a highly effective copper-catalyzeddecarboxylativecoupling of alkynylcarboxylic acids with various aryl and alkyl halides at 2 mol% loading of copper. This method is simple, economical and practical for the synthesis of disubstituted alkyne compounds.