共查询到19条相似文献,搜索用时 93 毫秒
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三甲基硅基(TMS)广泛存在于有机化合物中,并且在有机合成中有重要的应用。硅杂环化合物因其独特的理化性质而被广泛地应用于有机合成化学、材料化学和药物化学中。因此,将含有TMS基团的化合物直接用于硅杂环化合物合成的研究具有重要的意义。在有机合成化学中,碳硅键的切断是一个非常重要的过程。通过化学计量的有机镁或有机锂等有机金属试剂对C(sp3)-Si键进行切断是碳硅键活化的经典方法,然而该方法的反应条件苛刻,应用有限。过渡金属催化的反应能够在较温和的条件下实现C(sp3)-Si键的切断,这为进一步官能团化C(sp3)-Si键提供了一种新方向,同时也是一种高效构建硅杂环化合物的新方法。目前过渡金属催化活化C(sp3)-Si键的研究主要集中在具有张力环或一些具有特定结构的底物中,对于催化活化惰性C(sp3)-Si键的研究仍然是一个具有挑战性的课题。本文结合本课题组的工作综述了近年来过渡金属催化的TMS中C(sp3)-Si键的方法。 相似文献
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有机硅化合物在有机合成、材料化学和药物化学中都有广泛应用.因此,其自身的合成方法学在近年来广受关注.从原子经济性的角度出发,选择性的C(sp3)–H键切断是一种高效经济的合成策略.硅烷基单元在有机化合物中广泛存在,通过对硅烷基中的C(sp3)–H键直接官能团化来合成新的有机硅化合物是一种十分有前景的合成方法.近年来,过渡金属催化的C(sp3)–H键活化成为有机合成研究的热点领域.与肟基、唑啉、吡啶基、酰胺基、羧酸酯基等官能团或是与氧、氮或硫等杂原子相连的C(sp3)–H键的活化研究已有许多报道,但是与硅相邻的C(sp3)–H键活化研究报道很少.本文综述了近年来过渡金属催化的硅烷基C(sp3)–H键切断的研究进展. 相似文献
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本文对近年来可见光催化构筑C(sp 3)-C(sp 3)键的国内外最新研究成果进行概述,着重阐述了各类催化的催化体系、反应机理及在合成生物活性分子或药物分子方面的应用。在可见光催化的反应体系中引入过渡金属或手性催化剂,构建新颖的协同催化体系,可以实现在温和的条件下对C—C键构筑的精确控制,对于手性药物的设计、开发具有重要的意义。最后,对未来可见光催化构筑C—C键的发展进行展望。 相似文献
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碳-碳键的构建是有机反应中最常见的一类反应, 也是构建有机化合物骨架最常用的手段. 近些年, 通过脱羧反应来构建碳-碳键, 碳-杂原子键得到了广泛而深入的研究. 肉桂酸类化合物的脱羧偶联反应也得到了较多的关注. 这类反应一般包括两个过程, 自由基加成和羧基的脱去, 从而得到新的有机化合物. 这类反应的特点是用氧化剂产生自由基, 在反应过程产生二氧化碳和水为副产物, 相比使用卤代试剂或者有机金属试剂来说, 更为绿色. 作者在之前的研究过程基础上发现, 在无需任何金属催化剂的条件下, 只用过氧叔丁醇(有机溶剂)作为氧化剂, 肉桂酸类衍生物和酰胺类能够发生脱羧氧化偶联反应, 实现C(sp3)―C(sp3)键的生成. 该反应特点是没有用过渡金属盐作为催化剂, 符合绿色化学的发展要求. 相似文献
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The direct oxidative C(sp3)-H functionalization reaction has long been considered as one of the most efficient and straightforward synthetic protocol for the construction of C-C bonds. Recently, the synthesis of substituted quinolines via C(sp3)-H functionalization of glycine derivatives has gained widespread attention from the chemists. Recent progresses on the C(sp3)-H functionalization of glycine derivatives and their applications in the synthesis of substituted quinolines are described in this paper. The aims are to broaden students' vision and stimulate their interest in scientific research through the introduction of innovative scientific research. 相似文献
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《中国化学》2018,36(3):217-222
The first catalytic enantioselective C(sp)―C(sp3) cross‐coupling reaction between N‐tosylhydrazones and trialkylsilylethynes in the presence of Cu(I) salts and chiral phosphoramidite ligands was developed. A series of synthetically interesting, functionalized alkynes were obtained with moderate to good enantioselectivities (up to 83% ee). Cu(II) carbene migratory insertion is proposed to be the enantio‐determining step. 相似文献
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Zhiyang Yan Bin Sun Xun Zhang Xiaohui Zhuang Jin Yang Weike Su Can Jin 《化学:亚洲杂志》2019,14(19):3344-3349
A novel visible‐light‐driven decarboxylative coupling of alkyl N‐hydroxyphthalimide esters (NHP esters) with quinoxalin‐2(1H)‐ones has been developed. This C(sp2)?C(sp3) bond‐forming transformation exhibits excellent substrate generality with respect to both the coupling partners. Of note, a series of 3‐primary alkyl‐substituted quinoxalin‐2(1H)‐ones that were difficult to synthesize by previous methods could be obtained in moderate to excellent yields. Additionally, the mild conditions, easy availability of substrates, wide functional group tolerance and operational simplicity make this protocol practical in the synthesis of 3‐alkylated quinoxalin‐2(1H)‐ones. 相似文献
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《Tetrahedron letters》2014,55(50):6856-6860
This Letter described a facile approach to synthesize (E)-2-alkenylquinoline derivatives via C(sp3)-H functionalization of 2-methylquinolines under catalyst-free conditions. A variety of electronically and sterically diverse 2-methyl quinoline and aromatic aldehydes were well tolerated. 相似文献
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Hans Sterckx Bndicte Morel Bert U. W. Maes 《Angewandte Chemie (International ed. in English)》2019,58(24):7946-7970
Oxidation reactions are a key technology to transform hydrocarbons from petroleum feedstock into chemicals of a higher oxidation state, allowing further chemical transformations. These bulk‐scale oxidation processes usually employ molecular oxygen as the terminal oxidant as at this scale it is typically the only economically viable oxidant. The produced commodity chemicals possess limited functionality and usually show a high degree of symmetry thereby avoiding selectivity issues. In sharp contrast, in the production of fine chemicals preference is still given to classical oxidants. Considering the strive for greener production processes, the use of O2, the most abundant and greenest oxidant, is a logical choice. Given the rich functionality and complexity of fine chemicals, achieving regio/chemoselectivity is a major challenge. This review presents an overview of the most important catalytic systems recently described for aerobic oxidation, and the current insight in their reaction mechanism. 相似文献
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Polysulfonylamines. XCIV. Molecules with Unusually Long N(sp2)–Si(sp3) Bonds: Synthesis and Crystal Structures of 1,2-Benzenedisulfonylaminosilanes The following compounds were obtained by metathesis of silver 1,2-benzenedisulfonimide (AgZ) with the appropriate chlorosilanes: ZSiMe3 ( 4 ), ZSinPr3, ZSiMe2nBu, ZSiMe2(CMe2–CHMe2) ( 7 ), (Z)2SiMe2 ( 8 ). In the crystal structures of 4 (monoclinic, space group P21/n), 7 (monoclinic, P21/c) and 8 (monoclinic, P21/n), which were determined by low-temperature X-ray diffraction, the molecules adopt the N-silyl form and display unusually long bonds between the trigonal-planar N and the tetrahedrally coordinated Si atoms ( 4 : 182.6, 7 : 184.1, 8 : 177.8 and 180.5 pm). For 7 in CDCl3 solution, 1H and 13C NMR data indicate N,O-silylotropy. The solid state structures of molecules 4 and 7 strongly suggest that the N–Si bond lengthening in N,N-disulfonylated aminosilanes is mainly induced by the π-acceptor character of the SO2 groups and not by the occasionally observed coordination expansion of the Si atom through short intramolecular O…Si contacts. 相似文献