《化学通报》网络版2003年第6期论文摘要

[W 0 40 ]过渡金属催化炔烃芳环化反应研究进展 RecentAdvancesintheTransition Metal CatalyzedBenzannulationofUnsaturatedHydrocarbons李丽洋　夏海平 　丁马太 (厦门大学化学化工学院　福建厦门　 3 61 0 0 5 )综述了近年来在过渡金属催化下炔烃芳环化反应的研究进展 ,分别讨论了在不同过渡金属催化下由 [2 + 2 +2 ]和 [4+ 2 ]法制备高取代苯衍生物的反应实例 ,并介绍了此方法在高分子领域内的应用的初步进展 ,展现了过渡金属催化下不饱和烃反应广阔的应用前景。Progressinthetransition metal catalyzedbenzannulationofacetyle…     

Rh(Ⅱ)催化吲哚衍生物[3+3]环化机理及产物性质分析

采用密度泛函理论研究了双铑催化3-重氮吲哚啉-2-亚胺与2H-吖丙因[3+3]内环化反应过程. 该过程主要包含铑金属卡宾体形成、 C―N键活化裂解和吲哚啉[3+3]内环化反应. 研究结果表明, 双铑催化剂发生偶联作用, 促进C-N偶联及2H-吖丙因C―N键裂解; 反应控速步骤为吲哚[3+3]环化反应过程, 铑催化剂在[3+3]环化前脱出. 对产物吡嗪并吲哚类化合物光电性质的分析表明产物具有较低空穴重组能, 吸收与荧光发射光谱存在较大斯托克斯位移. 因此该产物可作为潜在的空穴传输材料和荧光发射材料.     

无过渡金属参与下光诱导的偶联反应构建碳-杂键的研究进展

近年来在光照条件下无过渡金属参与的偶联反应受到了广泛的关注,这些反应为C-N/S/P等键的构建提供了重要的方法,也在医药、农业或材料化工等领域得到了广泛的应用.重点介绍了近五年来在无过渡金属参与下由有机光氧化还原催化剂或光敏剂诱导构建C-N/S/P等键的光氧化还原反应.     

过渡金属催化合成吡咯-2-甲酸酯的研究进展

吡咯-2-甲酸酯广泛存在于生物活性分子中,在医药领域具有十分重要的应用,因此吡咯-2-甲酸酯类化合物的合成研究受到了广泛关注.过渡金属催化的环加成反应在合成吡咯骨架方面应用广泛,具有区域选择性专一的优点.且过渡金属配体导向的C-N键构筑方法具有原子步骤经济性较高、效率高、反应条件温和以及选择性高等优点.按照过渡金属催化剂分类,对吡咯-2-甲酸酯的[3+2]、[4+1]与[2+2+1]等成环反应的合成方法进行综述,介绍了过渡金属催化吡咯-2-甲酸酯化合物的机理及其应用,并对吡咯-2-甲酸酯的合成进行了展望.     

过渡金属催化炔烃环化反应的研究进展

具有独特反应性和稳定性的炔烃类化合物一直以来是科研工作者们关注的热点之一,其中关于炔烃环化构筑一系列多环化合物的反应报道尤为突出。本文根据不同金属催化剂,总结归纳了近几年铑、钌、钴、钯等过渡金属催化炔烃环化反应的研究进展,并简要讨论了催化转化的反应机理、优势以及局限性,最后展望了过渡金属催化炔烃环化反应的发展前景。     

木质素及其衍生物负载金属催化剂在有机合成中的应用研究进展

碳中和发展理念的提出使得生物质基催化剂的关注度不断提高,将木质素作为过渡金属催化剂的载体来制备非均相催化剂应用于有机合成领域,可以极大地提高木质素的利用价值.木质素结构中广泛存在的含氧官能团为金属催化剂的负载提供了多种结合位点,通过物理吸附/沉积、离子交换以及与羟基官能团通过静电络合可以有效地捕获金属粒子.首先介绍了木质素的结构,然后介绍了制备非均相催化剂的方法,重点介绍了木质素及其衍生物负载金属催化剂催化点击反应、Glaser反应、Huisgen [3+2]环加成反应、Heck反应、Suzuki反应、Sonogashira反应、Stille偶联反应、迈克尔加成/脱水串联反应、亲电开环反应、Fridel-Crafts型反应及乙烯聚合反应等,并对存在的问题和发展趋势进行了展望.     

Mn(Ⅰ)催化亚胺和炔烃脱氢偶联反应的机理研究

近年来随着过渡金属催化剂的发展和广泛使用,C—H键的活化成为了有机合成中的一大热点,尤其是在构建有机化合物C—C键中应用广泛.作为一种储量较大的廉价催化剂,Mn催化的C—H活化表现出巨大的应用价值和研究潜力.我们采用密度泛函理论(DFT),对1,4-二氧六环溶液中Mn活化C—H/N—H键实现[4+2]脱氢环化的反应机理进行了系统的研究.我们发现该反应的催化循环包括溴负离子辅助的催化剂引发、炔烃的插入、双键迁移成环、β-H消除释放产物异喹啉以及催化脱氢循环的C—H键活化等步骤.旨在深入理解Mn(I)活化C—H键脱氢气的具体过程,为更多Mn催化的C—H活化反应提供理论依据.     

酸促进2-乙烯基苯胺与重氮的[5+1]环化合成2-芳基喹啉

利用廉价易得的2-乙烯基苯胺与重氮化合物在三氟乙酸催化下发生[5+1]环化反应, 以中等至良好的产率合成了24种2-芳基喹啉衍生物. 该方法无需金属催化剂, 官能团兼容性好, 反应成本低, 不仅拓展了重氮化合物参与的新型有机反应, 同时也为2-芳基取代喹啉的合成提供了高效、 经济且简洁的新方法.     

螺烯制备方法的研究进展

综述了螺烯的制备方法方面的进展,述及的螺烯制备方法包括光化学反应、Diels-Alder反应、成烯关环反应以及过渡金属催化三炔的[2+2+2]环化异构化反应等.此外,文中还对螺烯的手性拆分方法进行了论述,并对双螺烯的制备设计予以展望.     

过渡金属盐及络合物在乙苯液相氧化中的催化作用

有机化合物中的C-H键选择性官能团化是有机合成中具有挑战性的课题之一。在不同的氧源(如H₂O₂、NaOCl、TBHP、RCOOOH、O₂等)作用下,许多过渡金属络合物可以选择性氧化有机物[1]。显然,由于分子氧廉价易得并且在氧化过程中对环境没有污染,所以分子氧是氧化反应的最理想的氧源。由于分子氧较难活化以及选择性方面的原因,在温和条件下过渡金属催化的分子氧选择性氧化过程受到了广泛的关注[2]。有关乙苯的液相催化氧化已有一些报道,比较有代表性的有以[W₁₀O₃₂]^4-和 CoC₁₂·6H₂O为催化剂的光催化氧化过程[3,4]、负载型的Ru络合物催化剂[5]以及在己醛存在下以Fe盐或Ru盐为催化剂的氧化过程[6]。本文在温和条件下(常压、110℃), 考察了不同过渡金属盐及络合物在乙苯液相氧化中的催化作用,着重考察了催化反应机理。     

Preparation and synthetic applications of alkene complexes of group 9 transition metals in [2+2+2] cycloaddition reactions

The [2+2+2] cycloaddition reaction has become an invaluable tool for the synthetic chemistry in recent years, due to the increase of complexity of the accessed target molecules by this methodology. Over several decades, the members of group 9 of the periodic table have contributed significantly to the development and understanding of this particular cycloaddition reaction. On the other hand, catalyst complexes containing alkenes as ligands are widely used today as either catalysts or as precursor molecules for the facile generation of catalytically active metal species. In this tutorial review we want to describe the catalytically relevant chemistry of group 9 metal-alkene complexes and compile some recent applications in [2+2+2] cycloaddition reactions.     

Consecutive Rh(I)-catalyzed Alder-ene/Diels-Alder/Diels-Alder reaction sequence affording rapid entry to polycyclic compounds

Conversion of acyclic allenynes to polycyclic compounds using consecutive transition metal catalyzed carbon-carbon bond forming reactions in a single chemical operation is described. Reaction of an allenyne with a Rh(I) catalyst affords a cross-conjugated triene via a formal Alder-ene reaction. The triene then participates in a Rh(I)-catalyzed intramolecular [4+2] cycloaddition reaction to generate a new conjugated diene. An external dienophile is added to this diene which then undergoes a second [4+2] cycloaddition reaction to afford a complex polycyclic ring system. This reaction sequence demonstrates the synthetic potential of allenynes and cross conjugated trienes and highlights the rapid increases in molecular complexity that are possible by one-pot sequential transition metal catalyzed carbon-carbon bond forming reactions.     

Recent advances in enantioselective [2 + 2 + 2] cycloaddition

Enantioselective cycloaddition using chiral transition metal catalysts is an atom-economical and efficient synthetic tool for the construction of chiral carbo- and heterocyclic skeletons. This short account discloses our recent results of inter- and intramolecular enantioselective [2 + 2 + 2] cycloadditions of alkyne and/or alkene moiety(ies). Chiral iridium complexes catalyzed the alkyne trimerization for the generation of axial chirality(ies), and chiral rhodium ones catalyzed alkyne-alkyne-alkene cyclization for the generation of a quaternary carbon including spirocyclic system.     

Nickel‐Catalyzed Synthesis of N‐Aryl‐1,2‐dihydropyridines by [2+2+2] Cycloaddition of Imines with Alkynes through T‐Shaped 14‐Electron Aza‐Nickelacycle Key Intermediates

Despite there being a straightforward approach for the synthesis of 1,2‐dihydropyridines, the transition‐metal‐catalyzed [2+2+2] cycloaddition reaction of imines with alkynes has been achieved only with imines containing an N‐sulfonyl or ‐pyridyl group. Considering the importance of 1,2‐dihydropyridines as useful intermediates in the preparation of a wide range of valuable organic molecules, it would be very worthwhile to provide novel strategies to expand the scope of imines. Herein we report a successful expansion of the scope of imines in nickel‐catalyzed [2+2+2] cycloaddition reactions with alkynes. In the presence of a nickel(0)/PCy₃ catalyst, a reaction with N‐benzylidene‐P,P‐diphenylphosphinic amide was developed. Moreover, an application of N‐aryl imines to the reaction was also achieved by adopting N‐heterocyclic carbene ligands. The isolation of an (η²‐N‐aryl imine)nickel(0) complex containing a 14‐electron nickel(0) center and a T‐shaped 14‐electron five‐membered aza‐nickelacycle is shown. These would be considered as key intermediates of the reaction. The structure of these complexes was unambiguously determined by NMR spectroscopy and X‐ray analyses.     

Asymmetric Cationic [P,O] Type Palladium Complexes in Olefin Homopolymerization and Copolymerization

Metal‐catalyzed ethylene homopolymerization and ethylene‐polar monomer copolymerization to produce new kinds of polyolefins with novel microstructures are of great interest. So far, there are some disadvantages for traditional transition metal catalyst systems. Therefore, it is critical to develop new catalysts or alternative strategies. In recent years, some cationic [P, O] palladium complexes have been demonstrated with the abilities to obtain oligomers and the high molecular weight polymers. Most importantly, these complexes showed high activity and generated polymers with specific microstructures when used for copolymerization of ethylene with industrially relevant polar monomers. This review summarizes several types of high performance cationic [P, O] palladium catalysts in ethylene oligomerization, ethylene homopolymerization and the copolymerization of ethylene with polar monomers. Specially, the regulation of steric and electronic effects at specific sites of the metal complexes was focused.     

The fascinating construction of pyridine ring systems by transition metal-catalysed [2 + 2 + 2] cycloaddition reactions

Cycloaddition reactions compose one of the most important classes of reactions when it comes to the simultaneous formation of several bonds in one reaction step. The de novo construction of carbocyclic aromatic systems from acetylenes was also found as an excellent possibility for the assembly of heteroaromatic systems. The transition metal-catalysed [2 + 2 + 2] cycloaddition reaction constitutes a fascinating tool for the synthesis of pyridines from nitriles and the most recent developments demonstrate the ability to control the substitution pattern as well as the possibility of introducing chirality by the use of achiral substrates and a chiral catalyst under mild conditions. In this tutorial review we are focusing on the de novo construction of pyridine ring systems by the transition metal-catalysed [2 + 2 + 2] cycloaddition reaction. After surveying the mechanistic features and intermediates of the reaction depending on the different metal complexes used, we depict the preparation of achiral pyridine derivatives. The last section describes the advances in the synthesis of chiral pyridines and biaryls using the cyclotrimerization method. The various possibilities of introducing chirality by catalytic means are presented and illustrated by instructive examples. This review will be of interest for people active in: Organic Chemistry, Organometallic Chemistry, Transition Metal Chemistry, Stereoselective Synthesis, Heterocyclic Chemistry.     

Catalytic [2,3]-sigmatropic rearrangement of sulfur ylide derived from metal carbene

This paper reviews the most recent development of [2,3]-sigmatropic rearrangement of sulfur ylide generated from the reaction of sulfide with metal carbene. The metal carbene was formed from decomposition of diazo compounds catalyzed by transition metal complexes such as Cu(I) and Rh(II).     

Visible Light‐Induced,Metal‐Free Denitrative [3+2] Cycloaddition for Trisubstituted Pyrrole Synthesis

A metal‐free, regioselective synthesis of trisubstituted pyrroles has been developed through a formal [3+2] cycloaddition reaction between 2H‐azirines and nitroalkenes under visible light/photoredox‐catalyzed conditions. The reaction proceeds through 2H‐azaallenyl radical addition on β‐nitrostyrenes in a Michael fashion followed by a base‐mediated denitration reaction. The directive group influence of the nitro group controls the regiochemistry of the reaction.     

exo- and enantioselective cycloaddition of azomethine ylides generated from N-alkylidene glycine esters using chiral phosphine-copper complexes

High diastereo- and enantioselectivities were obtained for the asymmetric 1,3-dipolar cycloaddition of azomethine ylides generated from N-alkylideneglycine esters with dipolarophiles using chiral phosphine-copper complexes as catalysts. Whereas the cycloaddition of azomethine ylides catalyzed by metal salts generally afforded endo-adducts as the predominant product, the present method is the first example of an exo-selective cycloaddition. [reaction: see text]     

Recent advances in [2+2+2] cycloaddition reactions

The [2+2+2] cycloaddition is an elegant, atom-efficient and group tolerant process for the synthesis of carbo- and heterocycles, mostly aromatic, involving the formation of several C-C bonds in a single step. Cyclotrimerisation is catalyzed by a variety of organometallic complexes, including more than 15 different metals. The aim of this tutorial review is to point out the most recent advances in this field and to encourage the use of this reaction enroute to complex molecules. After summarizing the most common catalysts and reaction conditions generally used, we survey the mechanistic features currently accepted for this reaction. Section 4 covers the scope of the different [2+2+2] cycloaddition versions starting with the cyclotrimerisation of three triple bonds, including nitriles, with especial emphasis on asymmetric reactions that create central, axial or planar chirality. Then, reactions that use double bonds are addressed. Finally, the most outstanding examples of natural products synthesis using [2+2+2] cycloadditions as a key step reported recently are shown.