Raney Ni–AI alloy in a dilute aqueous alkalinesolution has been shown to be a powerful reducing agent and is highly effective for the reduction of alkylbenzils and alkoxybenzils to afford the corresponding 1,2-diarylethers at 90°C, in the absence of organic solvents. 4,4′-Dinitrobenzil was transformed selectively to 1,2-bis(4-aminophenyl)-ethane.
of unactivated alkenes using ethanol as the hydrogen source is described. A new NCP-type pincer iridium complex (BQ-NCOP)IrHCl containing a rigid benzoquinoline backbone has been developed for efficient, mild TH of unactivated C-C multiple bonds with ethanol, forming ethyl acetate as the sole byproduct. A wide variety of alkenes, including multisubstituted alkyl alkenes, aryl alkenes, and heteroatom-substituted
描述了使用乙醇作为氢源实现未活化烯烃的转移氢化 (TH) 的第一种通用催化方法。已经开发出一种新的 NCP 型钳形铱络合物 (BQ-NCOP)IrHCl,其含有刚性苯并喹啉主链,可有效、温和地将未活化的 CC 多键与乙醇进行 TH,形成乙酸乙酯作为唯一的副产品。各种烯烃,包括多取代的烷基烯烃、芳基烯烃和杂原子取代的烯烃,以及含 O 或 N 的杂芳烃和内部炔烃,都是合适的底物。重要的是,(BQ-NCOP)Ir/EtOH 系统在反应性官能团(如酮和羧酸)存在下对烯烃氢化表现出高化学选择性。此外,与 C2D5OD 的反应为氘标记化合物提供了一条便捷的途径。详细的动力学和机理研究表明,单取代烯烃(如 1-辛烯、苯乙烯)和多取代烯烃(如环辛烯 (COE))表现出基本的机理差异。乙醇的 OH 基团在苯乙烯反应中显示出正常的动力学同位素效应 (KIE),但在 COE 的情况下显示出显着的反向 KIE。对
Nickel-Catalyzed Cross-Coupling of Umpolung Carbonyls and Alkyl Halides
作者:Dianhu Zhu、Leiyang Lv、Zihang Qiu、Chao-Jun Li
DOI:10.1021/acs.joc.9b00649
日期:2019.5.17
nickel-catalyzed cross-coupling of Umpolung carbonyls and alkylhalides was developed. Complementary to classical alkylation techniques, this reaction utilizes Umpolung carbonyls as the environmentally benign alkyl nucleophiles, providing an efficient and selective catalytic alternative to the traditional use of highly reactive alkylorganometallic reagents.
Synthesis of lactate derivatives via reductive radical addition to α-oxyacrylates
作者:Justin B. Diccianni、Mason Chin、Tianning Diao
DOI:10.1016/j.tet.2019.05.002
日期:2019.8
Lactate derivatives are important synthetic precursors to a variety of pharmaceutical products. Previously reported methods to prepare lactates require multiple steps or have limited scopes. Herein, we report a Ni-catalyzed reductive addition of a variety of alkyl iodides to α-oxyacrylates to afford substituted lactates. Exploring the scope of radical acceptors reveals that electron-deficient alkenes
Copper nanoparticle-catalyzed cross-coupling of alkyl halides with Grignard reagents
作者:Ju Hyun Kim、Young Keun Chung
DOI:10.1039/c3cc46419a
日期:——
A cross-coupling reaction between alkyl bromides and chlorides and various Grignardreagents was carried out in the presence of commercially available copper or copper oxide nanoparticles as a catalyst and an alkyne additive. The catalytic system shows high activity, a broad scope, and good functional group tolerance.