新型氮杂环卡宾银(I)配合物的合成及其晶体结构

以取代苄氯(1a~1c)为起始原料,与咪唑经氮烷基化反应制得苄基咪唑氯盐(2a~2c); 2a~2c与氧化银经原位去质子化反应合成了3种新型的氮杂环卡宾银配合物--(NHC)AgCl［NHC: 1,3-二(4-甲氧基苄基)咪唑-2-亚基(3a), 1,3-二(3-甲氧基苄基)咪唑-2-亚基(3b)］和［(NHC)AgCl]₂［NHC=1,3-二(4-氯苄基)咪唑-2-亚基(3c)］,其结构经¹H NMR, ¹³C NMR, IR,元素分析和X-射线单晶衍射表征。3a~3c单晶结构均属单斜晶系,3a为P2₁/n空间群,3b和3c为P2₁/c空间群,3a和3b为单核银配合物,3c为双核银配合物。     

一种阴离子功能化的氮杂环卡宾-锂配合物的合成与结构

氮杂环卡宾(NHC)作为有机膦的替代物在金属有机化学中的应用受到了愈来愈广泛的关注,由于其毒性小、给电子能力强、空间和电子效应很易通过改变氮原子上取代基进行调控,将这类配体用于后过渡金属催化剂,可大大改善这些催化剂在各类均相催化反应中的反应活性及选择性[1].     

新型氮杂环卡宾-钌(II)催化剂的合成及催化活性

以1,3-双(2,6-二异丙基苯基)咪唑鎓盐酸盐（IPrHCl, 4a)或1,3-双［2,6-二（1-乙基丙基）苯基］咪唑鎓盐酸盐（IPent·HCl, 5a),及Grubbs 第一代催化剂和2-异丙氧基苯乙烯为原料,经去质子化反应和烯烃复分解反应合成了两种新型的NHC-钌催化剂4c和5c,其结构经¹H NMR, ¹³C NMR和HR-MS(ESI)表征。并研究了4c和5c的性能。结果表明：4c和5c的稳定性较好,对关环复分解反应有良好的催化活性。     

镍(Ⅱ)基双氮杂环卡宾配合物的合成及其晶体结构

以咪唑和取代氯化苄为原料,经氮烷基化反应合成三个氮杂环卡宾(NHC)配体[L1:N,N-二苄基咪唑-2-亚基,L2:N,N-二(4-甲基苄基)咪唑-2-亚基,L3:N,N-二(4-氯苄基)咪唑-2-亚基];再以咪唑官能团化的N-杂环卡宾配体和氯化镍为原料,通过金属交换反应合成三个新型的镍基双氮杂环卡宾配合物[Ni(NHC)_2]Cl_2(C1~C3),其结构经~1H NMR,IR,元素分析和X-单晶射线衍射表征。配合物C1和C3属于单斜晶系,分别为P2_1/n和P2_1/c空间群。配合物C2属于三斜晶系,为P1空间群。C1~C3的CCDC分别为:1433176,1433177和1433179。     

水溶性氮杂环卡宾金属配合物的研究进展

氮杂环卡宾(NHCs)金属配合物作为一类重要的催化剂一直是有机合成领域研究的热点。近年来,通过引入水溶性配体而得到的水溶性氮杂环卡宾过渡金属配合物受到广大科研工作者的青睐。本文主要总结了水溶性NHCs的分类、合成及其在C-C偶联反应、复分解反应以及催化加氢反应中的应用,并对水溶性NHCs金属配合物的发展趋势进行了展望。     

氮杂环卡宾配位的单核型一价铁硫酚基配合物

含硫配体的低价铁物种被认为是固氮酶配位活化氮气时的活性金属物种, 但与之相关的含硫配体的单核型低价铁配合物的合成非常具有挑战性, 报道很少. 我们发现通过含氮杂环卡宾配体的三配位一价铁配合物(IMes)₂FeBr (IMes=1,3-bis(mesityl)imidazole-2-ylidene)与大位阻硫醇钾KSAr* (Ar*=2,6-(2',4',6'-Prⁱ₃C₆H₂)₂C₆H₃)的反应可以合成得到单核型一价铁硫酚基配合物[(IMes)Fe(SAr*)] (1). 配合物1为顺磁性配合物. 单晶X-射线衍射表征显示该一价铁配合物的铁中心除与一个氮杂环卡宾配位外还与大位阻硫酚配体的硫原子和2-位芳环以σ:η⁶-的方式配位. ⁵⁷Fe-穆斯堡尔谱、电子顺磁共振谱和理论计算共同表明配合物1的基态自旋量子数S=1/2. 配合物1可催化N₂与KC₈和Me₃SiCl反应, 生成N(SiMe₃)₃, 转换数(TON)可达87.     

金属氮杂环卡宾配合物的抗肿瘤活性研究进展

自1978年顺铂成功地被开发成癌症临床治疗药物以来,金属配合物作为小分子抗癌药物的开发成为人们的研究热点。其中,氮杂环卡宾能与多种过渡金属中心形成稳定的共价键,这种特殊的稳定性使得金属氮杂环卡宾配合物具有被开发成药物的潜能。近年来,金属氮杂环卡宾配合物被发现具有良好的抗癌活性,激发了广大无机药物化学研究者的研究热情。综合笔者课题组在金属氮杂环卡宾抗肿瘤配合物方面的前期研究,本文将对银、金、铑和铂氮杂环卡宾配合物的抗肿瘤活性及作用机制进行综述,以期为新型金属氮杂环卡宾抗肿瘤化合物的设计合成提供参考。     

咪唑类氮杂环卡宾金属配合物的合成与应用研究进展

氮杂环卡宾具有独特的结构和性质,可合成大量的氮杂环卡宾金属化合物,现在已发展为催化领域的重要配体之一,一直受到大量研究者的关注。本文综述了以咪唑作为基本单元搭载不同的杂原子基团合成一系列具有单齿、双齿和多齿型金属螯合物的方法及其在Suzuki偶联、Heck偶联等反应中的应用。     

氮杂环卡宾-铁配合物催化碳-碳偶联反应的研究进展

作为传统贵金属催化剂的理想替代品,铁具有来源广泛、毒性低和环境兼容性好等特点,目前被用于多种环境友好的催化过程。近年来,氮杂环卡宾(NHC)由于其独特的空间和电子性质,常作为配体,不仅能够被应用于贵金属(如钯、镍和铑等)催化,在铁催化中也得到了广泛的应用。本文综述了氮杂环卡宾及铁配合物催化剂的特点,并重点讨论了近十年其催化的碳-碳偶联包括芳基-芳基交叉偶联、芳基-烷基交叉偶联、烷基-烷基交叉偶联等反应中的研究进展。     

含吡啶鎓阳离子的氮杂环卡宾Pd(Ⅱ)配合物的合成、结构及催化性能

合成了四个含吡啶鎓阳离子的氮杂环卡宾钯(II)三碘配合物. 通过核磁共振谱和元素分析对它们进行了表征. 同时利用X射线单晶衍射确定了其中两个配合物的晶体结构. 研究表明该系列配合物对Suzuki-Miyaura偶联具有催化活性.     

环钯化二茂铁亚胺卡宾络合物的合成、表征及其对Buchwald-Hartwig胺化反应的催化性质

合成了一个新的二茂铁亚胺环钯化卡宾络合物, 并经过IR, 1H NMR, 13C NMR, HRMS和X射线衍射对其单晶结构进行鉴定. 新合成的催化剂对空气和湿气都很稳定, 并且对氯代苯参与的Buchwald-Hartwig胺化反应有较好的催化活性, 在摩尔分数为0.5%的催化剂用量下, 3 h即可以达到中等以上的收率.     

氮杂环卡宾催化的不对称安息香缩合反应

N-Heterocyclic carbene (NHC) plays an important role in catalytic processes, as the catalyst it has shown high activities in organic reactions. Synthesis of chiral triazole carbene, the structure and the application of NHCs in asymmetric catalytic benzoin reactions are described. The aims are to broad students' vision and make students feel the charm of organic chemistry through extension of undergraduate curriculum content. Meanwhile, their ability of finding, analyzing and solving problems on the basis of generalizing and thinking about the knowledge will be improved.     

Sterically Demanding AgI and CuI N-Heterocyclic Carbene Complexes: Synthesis,Structures, Steric Parameters,and Catalytic Activity

The synthesis and full characterization of new air-stable Ag^I and Cu^I complexes bearing structurally bulky expanded-ring N-heterocyclic carbene (erNHC) ligands is presented. The condensation of protonated NHC salts with Ag₂O afforded a collection of Ag^I complexes, and their first use as ligand transfer reagents led to novel isostructural Cu^I or Au^I complexes. In situ deprotonation of the NHC salts in the presence of a copper(I) source, provides a library of new Cu^I complexes. The solid-state structures feature large N-C_NHC-N angles (118–128°) and almost identical angles between the aryl groups on the nitrogen atoms and the plane of the N-C-N unit of the carbene (i.e. torsion angles close to 0°). Among the steric parameters, the percent buried volume (%V_bur) values span easily in the 50–57 % range, and that one of (9-Dipp)CuBr complex (%V_bur=57.5) overcomes to other known erNHC–metal complexes reported to date. Preliminary catalytic experiments in the copper-catalyzed coupling between N-tosylhydrazone and phenylacetylene, afforded 76–93 % product at the 0.5–2.5 mol % catalyst loading, proving the stability of Cu^I erNHC complexes at elevated temperatures (100 °C).     

Synthesis, Crystal Structure and Catalytic Behavior of 1-Ethyl-3-benyl-imidazolyl Tetranuclear N-Heterocyclic Carbene Silver Bromide

The title complex [Ag(carbene)2]2[Ag2Br4] has been synthesized by the reaction of Ag2O with 1-ethyl-3-benyl-imidazolium bromide in DMSO at room temperature, and characterized by elemental analysis, 1H NMR and single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P with a = 10.1597(10), b =11.0646(11), c = 13.0245(14) , α = 102.230(2), β = 90.606, γ = 113.9250(10)o, V = 1300.3(2) 3, Mr = 748.06, Z = 2, Dc = 1.911 g/cm3, μ(MoKα) = 4.60 mm-1 and F(000) = 728. The structure was refined to R = 0.0316 and wR = 0.0835 for 3744 observed reflections with I > 2σ(I). The title compound crystallizes as a centrosymmetric tetranuclear compound. One half of the molecule comprises the asymmetric unit of the structure. The Ag(1) atom is nearly linear or T-shaped when the Ag(1)-Ag(2) interaction is taken into consideration, which is bi-coordinated by two carbene carbon atoms. The Ag(2) atom adopts tetrahedral geometry. The catalytic behavior of the title complex has been investigated, and the results indicate it has a highly catalytic activation for L-lactide polymerization.     

Biological and Catalytic Applications of Pd(II)-Indenyl Complexes Bearing Phosphine and N-Heterocyclic Carbene Ligands

A general synthetic entryway into novel cationic Pd(II) indenyl complexes bearing one alkyl/aryl phosphine and one N-heterocyclic carbene is reported. All metal complexes have been exhaustively characterized by spectroscopic and structural analyses, highlighting that the indenyl fragment has an hapticity intermediate between η³ and η⁵. Most of the target complexes are stable in solid state and in solution for a long time. Two different applications of these organopalladium compounds are proposed. Firstly, they have been tested as antiproliferative agents towards three different ovarian cancer cell lines, showing a cytotoxicity significantly higher than that of cisplatin, with a clear dependence on the nature of the coordinated phosphine. Moreover, the similar cytotoxicity towards cisplatin-sensitive and cisplatin-resistant cell lines suggests that these new palladium derivatives act with a different mechanism of action with respect to classical platinum-based drugs. Finally, the water-soluble palladium complexes bearing 1,3,5-triaza-7-phosphaadamantane (PTA) have demonstrated interesting catalytic performances in Suzuki–Miyaura coupling in aqueous media, being, inter alia, readily and efficiently recyclable.     

过渡金属N-杂环卡宾配合物合成*

由于N-杂环卡宾配体（NHCs）的独特性能,N-杂环卡宾过渡金属配合物在均相催化等方面取得了重要应用,但是其合成方法却发展缓慢。本文综述了N-杂环卡宾过渡金属配合物合成方法的最新研究进展,介绍了富电子烯烃裂解反应、游离NHC直接配位反应、配体底物的脱质子原位反应、卡宾加合物热解反应、金属交换转移反应和C2-X（X为甲基、卤原子或氢原子）键氧化加成反应等合成N-杂环卡宾过渡金属配合物的主要方法,此外本课题组还首次发现了金属粉末法,该法可用于规模化合成铁、钴、镍、铜等第一过渡系金属NHC配合物。     

Heterobimetallic Coinage Metal-Ruthenium Complexes Supported by Anionic N-Heterocyclic Carbenes

The lithium complexes [(WCA-NHC)Li(toluene)] of anionic N-heterocyclic carbenes with a weakly coordinating borate moiety (WCA-NHC, WCA=B(C₆F₅)₃, NHC=IDipp=1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene) were used for the preparation of silver(I) or copper(I) WCA-NHC complexes. While the reactions in THF with AgCl or CuCl afforded anionic mono- and dicarbene complexes with solvated lithium counterions [Li(THF)_n]⁺ (n=3, 4), the reactions in toluene proceeded with elimination of LiCl and formation of the neutral phosphine and arene complexes [(WCA-NHC)M(PPh₃)] and [(WCA-NHC)M(η²-toluene)] (M=Ag, Cu). The latter were used for the preparation of chlorido- and iodido-bridged heterobimetallic Ag/Ru and Cu/Ru complexes [(WCA-NHC)M(μ-X)₂Ru(PPh₃)(η⁶-p-cymene)] (M=Ag, Cu, X=Cl; M=Ag, X=I). Surprisingly, these complexes resisted the elimination of CuCl, AgCl, or AgI, precluding WCA-NHC transmetalation.     

铂、铑N-杂环卡宾配合物在硅氢加成反应中的应用*

铂和铑的卡宾金属配合物作为催化剂应用于各种不饱和化合物的硅氢加成反应,表现出非常优良的催化性能和稳定的物理、化学性质,受到了化学工作者的广泛关注。本文对铂、铑N-杂环卡宾金属化合物作为催化剂在催化酮、炔烃、烯烃以及其它不饱和化合物硅氢加成反应中的应用作了介绍,并分析了该类催化剂在有机硅化学领域的应用前景。