醋酸钯催化直接芳基化合成2-芳基吲哚类化合物

为探究操作简便、绿色经济、底物适用性强的合成2-苯基吲哚类化合物的新方法,对反应溶剂、催化剂种类及用量、氧化剂种类和反应温度等反应条件进行筛选,选取最佳反应条件对取代吲哚及取代苯硼酸进行底物适用性实验,并进行结构表征。实验得到以物质的量分数为10%的Pd(OAc)₂为催化剂,物质的量分数为20%的Cu(OAc)₂为氧化剂,冰乙酸为溶剂,室温反应8 h为最佳反应条件,共合成了23个2-芳基吲哚类化合物,产率高达87%。本实验开发了一步合成2-芳基吲哚类化合物的方法,该方法对不同取代的吲哚和苯硼酸均具有较好的适用性,与已报道的方法相比,本方法具有底物适用性强、产率高、操作简便、经济环保等优点,为2-芳基吲哚类化合物的制备提供了更加高效的路径。     

过渡金属催化脱羧反应研究进展

羧基是有机化合物常见的官能团,对于羧酸类化合物,一般都需要在很高的温度下才可以使它们脱去CO2分子,随着过渡金属催化的偶联反应的发展,从而相应的过渡金属催化的脱羧反应也得到了发展,文章中我们将对各种过渡金属(如Pd、Cu、Rh等)催化下的脱酸反应进行介绍。     

过渡金属催化碳-氢键活化反应的研究进展

碳-氢键活化是有机合成中最具有挑战性的课题之一,受到化学家们的广泛关注。寻找环境友好的催化剂体系进行碳-氢键活化从而构建碳-碳键、碳-杂键具有重要的理论意义和应用价值。本文综述了近年来过渡金属催化碳-氢键活化反应的研究进展,主要包括不同类型的(sp,sp2,sp3)碳-氢键的活化反应及其反应机理的探讨。     

过渡金属络合物催化合成联萘酚

使用CuCl 四甲基乙二胺络合物催化β 萘酚氧化偶联,联萘酚产率可达80%以上。考察了金属盐种类、配体用量对联萘酚产率的影响。当采用手性配体L 尼古丁或(1S,2R) 盐酸麻黄碱时,联萘酚产率中等,光学收率较低。     

过渡金属催化含氟烷烃的偶联反应

氟原子具有较小的分子半径与较高的电负性,在有机分子中引入氟原子后常常能改变分子的物理、化学及生物学性质。过渡金属催化含氟烷烃的偶联反应是制备含氟化合物的重要方法之一。以含氟有机原料为砌块构建各类含氟有机化合物已受到广泛关注。重点介绍了近年来过渡金属钯、镍、铜催化的各类含氟烷烃的偶联反应。     

过渡金属催化的羧酸脱羧碳-杂原子偶联反应研究进展

羧酸具有价廉、易得、易于运输存储等特点。与传统的有机金属试剂相比,羧酸经过渡金属催化脱羧后生成的有机金属中间体同样具有很好的与亲核试剂偶联或与亲电试剂反应的活性,以羧酸为反应试剂经脱羧与碳原子或杂原子偶联为化学键的构建提供了新的思路,尤为重要的是羧酸经脱羧偶联通常只产生一分子二氧化碳。大量的脱羧碳-碳、碳-杂键成键反应已被报道,其中包括SP碳羧酸、SP2碳羧酸、SP3碳羧酸。本文着重介绍羧酸脱羧与杂原子偶联反应,包括脱羧质子化、碳-氮、碳-氧、碳-硫、碳-硒、碳-卤、碳-磷键成键反应。     

铑催化芳酮脱羰基合成联芳基化合物

以含氮杂环为导向基、过渡金属铑络合物[Rh(cod)Cl]2为催化剂,通过碳碳键活化将芳酮化合物脱羰基合成联芳基化合物。确定最优反应条件为:底物芳酮用量2mmol、铑催化剂[Rh(cod)Cl]2用量2.5%(摩尔分数)、溶剂二甲苯用量5mL、反应温度130℃、反应时间12h,在此条件下,联芳基化合物收率达到90%。     

过渡金属催化下的格氏试剂与卤代烃的偶联反应研究进展

格氏试剂与卤代烃的偶联反应是有机合成中形成C-C健的重要方法.详细介绍了各种过渡金属催化下的偶联反应,从机理、过程和方法上进行了探讨,并展望该领域未来的发展方向.     

过渡金属催化C-H键活化多组分串联环化反应

在现阶段的化学合成科研中,备受瞩目的是利用金属催化有机分子C-H键的活化,金属中的过渡金属在活化反应中原子经济性好,导向性强。与此同时杂环化合物的合成工作中多组分反应正处于快速繁荣发展的阶段。因而利用过渡金属催化多组分串联反应制备诸多的杂环化合物,是用于有机化合物环化反应最有效的反应模式之一。本文重点综述了过渡金属催化的C-H键活化多组分串联反应制备医药类杂环化合物骨架分子的最新工作进展。     

离子液体中CuI/L-Proline催化C-S偶联反应的研究

以氯代苯甲醛,氯代硝基苯与硫酚为原料,在室温离子液体中,用L-脯氨酸与CuI为催化体系,成功的进行了偶联反应。合成一类新型的含醛基,硝基等基团的二苯硫醚类化合物。     

First Application of Secondary Phosphines as Supporting Ligands for the Palladium‐Catalyzed Heck Reaction: Efficient Activation of Aryl Chlorides

Secondary dialkylphosphines were successfully used for the first time as efficient supporting ligands for the palladium‐catalyzed Heck reaction of electron‐rich and electron‐poor aryl chlorides with olefins such as acrylate, ethylene, styrene, and n‐butyl vinyl ether. The yields with HP(t‐butyl)₂ and HP(adamantyl)₂ were comparable or better than those obtained with known systems of tertiary phosphines such as P(cyclohexyl)₃ and P(t‐butyl)₃, especially at a catalyst loading of <1 mol %. In comparison with tertiary phosphines, the secondary phosphines have the advantage of being readily available at low cost on a technical scale, and are comparable with respect to handling and oxygen sensitivity.     

金属钯催化的偶联反应的研究总结

偶联反应是一类构建碳-碳键的重要化学反应,其应用十分广泛。本文对钯催化的Suzuki、Heck、Sonogashira、Kumada、Negishi、Stille、Hiyama等偶联反应的研究进行了综述,分析了上述反应的优缺点及研究成果,并对该类反应的发展前景进行了归纳总结。     

Copper‐Catalyzed Three‐Component One‐Pot Synthesis of Aryl Sulfides with Sulfur Powder under Aqueous Conditions

A copper‐catalyzed three‐component (arenes, iodohydrocarbon, and sulfur powder) synthesis of substituted aryl sulfides has been developed. Water is used as the green solvent in a simple and environmentally friendly procedure. Various functional groups attached to the substrates were well tolerated in this process to afford the corresponding products in moderate to good yields.

     

Palladium‐Catalyzed,Highly Efficient,Regiocontrolled Arylation of Electron‐Rich Allylamines with Aryl Halides

The highly efficient and regioselective palladium‐catalyzed Heck coupling of aryl bromides with electron‐rich allylamine derivatives is described. It was found that the choice of solvent, olefin, ligand and additive had a fundamental influence on the regioselectivity and reactivity of the reaction. The combination of palladium acetate [Pd(OAc)₂] and 1,3‐bis(diphenylphosphino)propane (dppp) in ethylene glycol (EG) constitutes a highly effective catalyst system for internal arylation of N‐Boc‐allylamine (tert‐butyl methyl allyliminodicarbonate) with aryl bromides to give good to excellent regioselectivities, while the catalyst system consisting of Pd(OAc)₂, tetrabutylammonium bromide (TBAB) and 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) additive allows for a variety of aryl bromides to react efficiently with N,N‐(Boc)₂‐allylamine (di‐tert‐butyl allyliminodicarbonate) in water to exclusively afford the linear (E)‐allylamine products in high yields.     

Transition Metals Catalyzed Element-Cyano Bonds Activations

Cyano group as a versatile functionalized intermediate has been explored for several decades, as it readily transfers to many useful functionalization groups such as amine, amide, acid, etc., which make it possess high popularization and use value in organic synthesis. Reactions involved with element-cyano bond cleavage can provide not only a new cyano group but also a freshly functionalized skeleton in one-pot, consequently making it of high importance. The highlights reviewed herein include H-CN, Si-CN, C-CN, B-CN, Sn-CN, Ge-CN, S-CN, Halo-CN, N-CN, and O-CN bonds cleavages and will summarize progress in such an important research area. This review article will focus on transition metal catalyzed reactions involving element-cyano bond activation.     

Synthesis of Aryl Carbamates via Copper‐Catalyzed Coupling of Aryl Halides with Potassium Cyanate

Coupling of aryl halides with potassium cyanate takes place at 100–110 °C in alcohols under the catalysis of CuI (cuprous iodide) and 2‐(2,6‐dimethylphenylamino)‐2‐oxoacetic acid, affording the corresponding aryl carbamates with great diversity.     

Practical Iron‐Catalyzed Allylations of Aryl Grignard Reagents

An operationally simple iron‐catalyzed reductive cross‐coupling reaction between aryl halides and allyl electrophiles has been developed. The underlying domino process exhibits high versatility with respect to the allylic leaving group (acetate, tosylate, diethyl phosphate, methyl carbonate, trimethylsilanolate, methanethiolate, chloride, bromide) and high economic and environmental sustainability with respect to the catalyst system (0.2–5 mol% tris(acetylacetonato)iron(III), ligand‐free) and reaction conditions (tetrahydrofuran, 0 °C, 45 min).     

Palladium‐Catalyzed α‐Arylation of Methyl Sulfonamides with Aryl Chlorides

A palladium‐catalyzed α‐arylation of sulfonamides with aryl chlorides is presented. A Buchwald‐type pre‐catalyst formed with Kwong’s indole‐based ligand enabled this transformation to be compatible with a large variety of methyl sulfonamides and aryl chlorides in good to excellent yields. Importantly, under the optimized reaction conditions, only mono‐arylated products were observed. This method has been applied to the efficient synthesis of sumatriptan, which is used to treat migraines.

     

过渡金属配合物催化烯烃的自由基反应进展

近年来，通过烯烃官能团化构建有机化合物成为有机合成领域的研究热点之一。当选择种类、晶体结构和性能多样的过渡金属配合物作为催化剂时，这类反应具有高效、高选择性且成本低的特点。本文总结了近五年来利用过渡金属盐及其配合物作为催化剂，经过自由基反应历程实现未活化烯烃官能团化的研究进展，其反应特点是在过渡金属催化下，烯烃生成自由基并与其它底物或试剂偶联成键，从而实现官能团化。其中，催化性能优异的催化剂除了贵重金属铑、钯和钌等的配合物之外，还有普通金属，如铁、镍、铜和钴的盐及其配合物。这些方法拓展了烯烃官能团化的研究领域，为有机合成工作者提供新方法和思路，还为将来的产业化生产提供新方案。