Negishi偶联反应的研究进展

对有机锌试剂参与的Negishi偶联反应机理进行了简要概述,并详细综述了Negishi偶联反应的研究进展,主要介绍了Pd、Ni催化剂以及新型Fe、Co催化剂参与的Negishi偶联反应。展望了新型催化剂的发展趋势。     

镍催化环丁酮肟酯与芳基锌试剂的Negishi偶联反应

发展了一种镍催化环丁酮肟酯和芳基锌试剂之间Negishi偶联的方法.镍既作为亚胺自由基的引发剂,也作为芳基锌试剂与烷基自由基偶联反应的催化剂在反应中起作用.本方法可避免使用剧毒的氰化物,且具有很广的底物适应性和官能团兼容性,因此可能是一种具有潜在吸引力的高效合成烷基腈类化合物的新策略.初步的机理研究显示,该反应极可能经历自由基历程.     

镍催化环丁酮肟酯与芳基锌试剂的Negishi偶联反应（英文）

发展了一种镍催化环丁酮肟酯和芳基锌试剂之间Negishi偶联的方法.镍既作为亚胺自由基的引发剂,也作为芳基锌试剂与烷基自由基偶联反应的催化剂在反应中起作用.本方法可避免使用剧毒的氰化物,且具有很广的底物适应性和官能团兼容性,因此可能是一种具有潜在吸引力的高效合成烷基腈类化合物的新策略.初步的机理研究显示,该反应极可能经历自由基历程.     

微波辐射下水中6-氯嘌呤(核苷)及8-溴嘌呤核苷的脱卤反应

以6-氯嘌呤,6-氯嘌呤核苷或8-溴嘌呤核苷为原料,微波辐射下与水合肼反应生成相应的6-肼嘌呤(2a～2e),6-肼嘌呤核苷(2f和2g)或8-肼嘌呤核苷(2h和2i);2在微波辐射下经Wolff-Kishner-HuangMinlon还原反应得到6-脱氯嘌呤,6-脱氯嘌呤核苷或8-脱溴嘌呤核苷,总收率46%～83%,其结构经1HNMR和13CNMR表征。     

固相有机合成中钯催化的交叉偶联反应研究进展

过渡金属钯催化交叉偶联反应是形成碳一碳键的一种十分有效的方法,因此钯催化的C—C偶联反应引起了更多人们的广泛关注,并发展了多种不同的C—C偶联反应,包括Heck反应、Negishi反应、Suzuki偶联和Stille偶联等。固相有机合成具有反应条件温和、可使多种活性官能团兼容、受空间位阻影响小、具有高度的化学选择性、毒...     

水相中锌促进的羰基化合物频哪醇偶联反应实验设计

介绍水相中锌促进的羰基化合物频哪醇偶联反应的实验设计。通过苯甲醛频哪醇偶联反应得到相应的1,2-二苯基．1,2-乙二醇,学习水相有机反应和微量反应的基本操作,加强基础研究、绿色化学与有机化学实验之间的紧密联系。     

创新综合化学实验:烷基-烷基Kumada偶联反应*

为将交叉偶联反应引入本科化学实验教学中,设计了创新综合化学实验——Kumada偶联反应。该实验选取氯化亚铜作催化剂,常温下即可反应,溶剂低毒,反应时间短,产率高,符合“绿色化学”理念。该实验在无水无氧条件下进行偶联反应,再通过萃取、分液、柱层析对产物进行分离,并引入气相色谱对产物进行定性和半定量分析。通过该实验项目的学习,学生可以掌握典型的有机化合物合成、分离手段并熟悉大型仪器设备的分析技术。     

过渡金属催化的惰性碳氢键卤化反应研究进展

卤化反应是有机化学中最重要的反应之一,近年来,过渡金属催化的碳氢键卤化反应已经成为合成有机卤化物的重要方法.本文综述了过渡金属催化的惰性碳氢键卤化的研究进展,按照不同的过渡金属(钯、铜、铑、钌、钴)对底物范围和反应机理等进行详细的探讨,并对该领域的局限性和未来发展进行了总结和展望.     

活性锌的制备及其用于某些有机反应的研究

活性的零价态金属是低价金属有机化学中引人注目的研究课题,它可以改进金属参与的有机反应,简化合成步骤,提高产率或在温和条件下合成金属有机化合物。用非水体系,在惰性气氛下还原法制备活性金属,方法简便,不需特殊设备,因而引起了人们的兴趣。     

Nickel-Catalyzed Cross-Coupling of Ethyl Chlorofluoroacetate with Aryl Bromides

A combinatorial nickel-catalyzed monofluoroalkylation of aryl bromides with the industrial raw regent ethyl chlorofluoroacetate has been developed. The two key factors to successful conversion are the combination of nickel with readily available nitrogen and phosphine ligands and the using of a mixture of different solvents. Mechanistic investigations indicated a new zinc regent might generated in situ and be involved in the reaction process.     

Nickel-Catalyzed Kumada Cross-Coupling Reactions of Benzylic Sulfonamides

Herein, we report a Kumada cross-coupling reaction of benzylic sulfonamides. The scope of the transformation includes acyclic and cyclic sulfonamide precursors that cleanly produce highly substituted acyclic fragments. Preliminary data are consistent with a stereospecific mechanism that allows for a diastereoselective reaction.     

Cross-Coupling of Aryllithiums with Aryl and Vinyl Halides in Flow Microreactors

The use of Pd catalysts that contained a carbene ligand, such as PEPPSI-SIPr, speeded up the Murahashi coupling of ArLi with ArBr, by enabling its integration with the Br/Li exchange of ArBr with BuLi in flow. Space integration realized the rapid cross-coupling of two different ArBr substrates. However, the cross-coupling reaction with vinyl halides could not be achieved under similar conditions. Pd(OAc)₂ was an effective catalyst, and the space integration of the Br/Li exchange of ArBr with BuLi and the Murahashi coupling with vinyl halides was successfully achieved.     

镍催化氟代烯基硼酯与烷基卤化物Suzuki偶联反应

有机化合物特定位点嵌入氟原子或含氟片段,可以产生独特的生物或物理性质改变.单氟取代烯基是生物医药领域理想的酰胺键替代物,在医药化学、药物研发等方向已经获得广泛的应用.通过溴化镍（Ⅱ）二乙二醇二甲醚复合物、4,4'-二叔丁基-2,2'-二吡啶的催化体系,实现了多种氟代烯基硼酯与一级烷基卤化物碘代物、溴代物以及二级烷基溴代物的Suzuki偶联反应.该反应具有良好的收率和优秀的官能团兼容性,能够兼容酯基、氰基、醇羟基等多种具有有机合成化学价值的官能团,为单氟取代烯烃的合成提供了方法.机理实验表明该反应可能经历烷基卤化物自由基均裂历程.     

Mild Cobalt‐Catalyzed Negishi Cross‐Couplings of (Hetero)arylzinc Reagents with (Hetero)aryl Halides

A catalytic system consisting of CoCl₂ ? 2 LiCl (5 mol %) and HCO₂Na (50 mol %) enables the cross‐coupling of various N‐heterocyclic chlorides and bromides as well as aromatic halogenated ketones with various electron‐rich and ‐poor arylzinc reagents. The reactions reached full conversion within a few hours at 25 °C.     

Nickel-Catalyzed Electrochemical Reductive Relay Cross-Coupling of Alkyl Halides to Aryl Halides

A highly regioselective Ni-catalyzed electrochemical reductive relay cross-coupling between an aryl halide and an alkyl halide has been developed in an undivided cell. Various functional groups are tolerated under these mild reaction conditions, which provides an alternative approach for the synthesis of 1,1-diarylalkanes.     

Negishi Cross-Coupling in the Preparation of Benzyl Substituted Pyrrolo[2,3-d]pyrimidine Based CSF1R Inhibitors

The colony-stimulating factor 1 receptor (CSF1R) is a protein kinase emerging as an attractive target with clinical relevance in cancer, CNS and inflammatory diseases. Molecular docking experiments followed by synthesis and structure–activity relationship have been used to identify low molecular weight structures as promising hits for lead optimization. These molecules are synthesized from a 4-chloro-6-iodo-pyrrolo[2,3-d]pyrimidine building block using Negishi and Suzuki–Miyaura cross-coupling reactions in high yields. Several inhibitors possessed excellent enzymatic potency, and the parent compound preferably binds to the autoinhibited form of CSF1R. Cellular and in vivo profiling indicate that further tuning of drug structure is needed prior to efficacy studies.     

镍催化的芳基硼酸偕二氟炔丙基化反应

偕二氟炔丙基取代的芳烃是一类非常重要的化合物, 但传统合成该类化合物的方法却存在很大局限性. 以过渡金属催化直接向芳烃偕二氟炔丙基化是一种高效简洁制备上述化合物的方法. 以廉价易得的Ni(NO₃)₂·6H₂O为催化剂, 首次实现了镍催化下芳基硼酸与α,α-二氟炔丙基溴的偶联反应. 该反应不仅温和高效、原料廉价易得、官能团兼容性良好, 而且还能进行克量级放大和对生物活性分子的后期氟修饰, 从而为新药研发提供了一种有效手段.     

Nickel-catalyzed carbonylative Negishi cross-coupling reactions

Catalytic carbonylative Negishi cross-coupling reactions are described. This method readily provides various enones from enol triflates and diorganozinc reagents with catalytic amounts of nickel(II) chloride-4,4′-dimethoxyl-2,2′-bipyridyl under carbon monoxide atmosphere. The rate of carbon monoxide insertion is increased by the addition of lithium or magnesium halides and the use of polar solvents. Alkenyl iodides can also be used in place of enol triflates.