钯催化卤代芳烃的胺化反应研究

钯催化卤代芳烃胺化是形成Car-N的重要方法.配体的发展扩展了底物的适用范围, 提高了反应的选择性,实现了廉价易得的氯代芳烃的胺化,弱碱的使用提高了官能团的兼 容性,因此Pd催化芳胺化广泛应用于合成芳胺类化合物.本文以卤代芳烃为线索,对钯催化偶联胺化反应的研究进展进行了综述和展望.     

钯等过渡金属催化的卤代芳烃和胺的偶联反应

综述了钯等过渡金属催化的卤代芳烃或芳基碘酸酯和胺的偶联反应以及催化这 一新反应的催化剂的发展和应用。用于该反应的配体由P（o-tolyl)3发展到BINAP 及二烷基芳基膦，基底物由溴代芳烃扩展到经济易得的氯化芳烃及碘酸酯和各种胺。     

钯催化卤代芳烃Ullmann偶合反应

Ullmann偶合反应是有机合成中构建碳—碳键最重要的方法之一. 综述了钯催化卤代芳烃Ullmann偶合反应的研究进展, 其中包括钯催化还原Ullmann偶合反应和钯催化氧化Ullmann偶合反应等两部分.     

钯催化剂催化交叉偶联反应形成P-C键和复杂含磷化合物的研究进展

综述了利用金属钯催化交叉偶联反应形成P-C键以合成各种复杂的含磷化合物特别是手性膦配体的研究进展;介绍了参加偶联反应的不同价态的P化合物亲核试剂,以及卤代烯烃、卤代芳烃、三氟甲磺酸烯基脂、三氟甲磺酸芳基脂、乙烯基硼酸脂等亲电试剂;探讨了相应的偶联反应的反应条件、反应机理及其在材料、医药、农药等领域的应用.     

在催化体系可回收和无配体条件下溴化四丁基铵中钯催化卤代芳烃与芳基硼酸的Suzuki-Miyaura交叉偶联反应

我们发展一种在催化体系可回收和无配体条件下溴化四丁基铵（TBAB）中钯催化卤代芳烃与芳基硼酸的Suzuki-Miyaura交叉偶联反应方法。我们发现水的量对反应有很大的影响。当水的用量为1 %（质量比）时,反应的结果最好。在3 mol%的醋酸钯和1.5 g的TBAB（含1%的水）,一系列卤代芳烃与芳基硼酸的顺利地发生Suzuki-Miyaura交叉偶联反应,得到中等及良好的产率。而且在溴代芳烃和活泼的氯代芳烃的交叉反应中,Pd(OAc)2/TBAB催化体系可以回收重复使用多次,并且催化活性基本不变。     

碘化亚铜/乙二胺催化氮杂环化合物的N-芳基化反应

以碘化亚铜/乙二胺为催化体系,研究了卤代芳烃和氮杂环化合物的Ullmann反应。 结果表明,氮杂环化合物的pKa越小,芳基化反应越容易进行,p-π共轭形成的富电子卤代芳烃有利于反应,非p-π共轭的富电子卤代芳烃使反应变难。     

1,1-二卤代-1-烯烃的制备及其在有机合成中的应用

1,1-二卤代-1-烯烃是有机化学中常见的合成片断,在合成化学中已得到了广泛的应用。该综述介绍了这一类化合物常见的制备方法以及反应的适用范围,并详细讨论了该类化合物在有机合成中的应用：(1)1,1-二卤代-1-烯烃在镁、有机锂、锌/溴化亚铜、二碘化钐、零价钯等金属或金属试剂作用下,发生α-消除反应生成烯基卡宾中间体的反应;(2)1,1-二卤代-1-烯烃在合成杂环以及核苷类似物等方面的应用。对于这类化合物在钯催化下的分子内(间)的偶联反应以及利用分子内的双环碳钯化反应,合成环状化合物等等方面的研究进展,也进行了详细的讨论。     

经由酸促进二硫缩烯酮取代的吲哚直接乙烯基化：吲哚生物碱Meridianins衍生物的高效合成

一级芳胺广泛用于天然产物、药物、高分子和材料的合成中,传统合成一级芳胺是在高温、高压和封闭容器中采用钯催化卤代芳烃与氨气反应来制备,也可以在钯催化下使用氨的替代物,如Li[N（SiMe3）2],Zn[N（SiMes）2]与卤代芳烃反应来合成．显然,这些方法有以下缺点：（a）由于采用钯催化剂和复杂的配体,成本较高、毒性较大;（b）当使用氨气作为氨基源时,高温、高压和封闭容器是必不可少的;（c）当使用氨的替代物作为氨基源时,由于这些氨的替代物不易制备、成本也就较高．清华大学化学系付华课题组建立了一种合成一级芳胺的新方法.     

无配体钯催化乙醇水溶液中芳基三氟硼酸钾的Suzuki反应

发展了一个无配体钯催化芳基三氟硼酸钾的Suzuki反应体系.该体系在空气条件下,以醋酸钯为催化剂,1equiv.的无水碳酸钾为碱,在乙醇水溶液中可高效催化卤代芳烃或杂环卤代芳烃与芳基三氟硼酸钾的Suzuki反应,周转频率(TOF)值最高达4656 h~(-1),且该体系还适用于三苯胺衍生物的合成.透射电镜分析结果及汞中毒实验证明该体系的实际催化物质为原位生成的纳米钯粒子.     

乙二胺功能化纤维素负载纳米钯催化Suzuki反应的研究

以氯化纤维素为原料, 通过与乙二胺的胺化反应制得乙二胺功能化纤维素(Cell-EDA), 然后再将胺化纤维素在氯化钯乙醇溶液中反应可以方便制备得到乙二胺功能化纤维素负载的纳米钯催化剂(Cell-EDA-Pd0). 用SEM, TEM等分析方法对所制备的催化剂进行了表征; TEM分析表明乙二胺功能化纤维素负载的纳米钯呈球形, 粒径在10～20 nm左右. 实验结果表明, Cell-EDA-Pd0催化剂对空气稳定, 无需在惰性气体的保护下就能有效地催化芳基硼酸与卤代芳烃的Suzuki交叉偶联反应, 催化剂易回和收重复使用, 催化剂重复使用6次催化活性没有明显降低.     

One-pot aromatic amination based on carbon–nitrogen coupling reaction between aryl halides and azido compounds

An efficient copper-mediated C–N coupling reaction between various aryl halides and azido compounds to produce the corresponding aromatic primary amines was established. The present amination is apparently involved in both the reduction of an azido functionality to the corresponding primary amino group and its cross-coupling reaction with aryl halides in a one-pot manner. The present amination could be applied to the synthesis of procaine, a local anesthetic drug. A mechanistic study indicated that 2-aminoethanol could work as a major hydrogen donor and the reaction would proceed without the formation of the intermediary aryl azide.     

Palladium-catalyzed amination of aryl halides on solid support

[reaction: see text] The first examples of the Pd(0)-catalyzed amination of aryl halides using Rink-resins as nitrogen source are described. Pd(2)dba(3)/BINAP/NaO-t-Bu was found to be the most efficient catalyst/base system, while a solvent mixture of dioxane and tert-butyl alcohol was shown to enhance the selectivity toward the desired monoarylation. Moderate to good yields and excellent purities of the amination products were found with electron-poor aryl halides, while electon-rich aryl halides failed to react under these conditions.     

Reductive Molybdenum‐Catalyzed Direct Amination of Boronic Acids with Nitro Compounds

The synthesis of aromatic amines is of utmost importance in a wide range of chemical contexts. We report a direct amination of boronic acids with nitro compounds to yield (hetero)aryl amines. The novel combination of a dioxomolybdenum(VI) catalyst and triphenylphosphine as inexpensive reductant has revealed to be decisive to achieve this new C?N coupling. Our methodology has proven to be scalable, air and moisture tolerant, highly chemoselective and engages both aliphatic and aromatic nitro compounds. Moreover, this general and step‐economical synthesis of aromatic secondary amines showcases orthogonality to other aromatic amine syntheses as it tolerates aryl halides and carbonyl compounds.     

Expanding Pd-catalyzed C-N bond-forming processes: the first amidation of aryl sulfonates,aqueous amination,and complementarity with Cu-catalyzed reactions

The first general method for the Pd-catalyzed amination of aryl tosylates and benzenesulfonates was developed utilizing ligand 1, which belongs to a new generation of biaryl monophosphine ligands. In addition, the new catalyst system for the first time enables amidation of aryl arenesulfonates and aqueous amination protocols that do not necessitate the use of cosolvents. The substrate scope has been significantly expanded to include aryl halides containing primary amides and free carboxylic acid groups. In the case of multifunctional substrates, the Pd-catalyzed amination can provide selectivity that is complementary to the Cu-catalyzed C-N bond-forming processes.     

Ligand free open air copper(II) mediated aryl formamidation and amination of aryl halides

A simple synthetic procedure for direct formamidation and amination of aryl halides mediated by copper(II) salts was developed in open air, without an external ligand in formamide with potassium carbonate as a base. This approach is particularly efficient when electron active aryl halides are used as substrates. In these cases almost quantitative formamidation was observed.     

Formal Direct Cross‐Coupling of Phenols with Amines

The transition‐metal‐catalyzed amination of aryl halides has been the most powerful method for the formation of aryl amines over the past decades. Phenols are regarded as ideal alternatives to aryl halides as coupling partners in cross‐couplings. An efficient palladium‐catalyzed formal cross‐coupling of phenols with various amines and anilines has now been developed. A variety of substituted phenols were compatible with the standard reaction conditions. Secondary and tertiary aryl amines could thus be synthesized in moderate to excellent yields.     

Hemilabile‐coordinated copper promoted amination of aryl halides with ammonia in aqueous ethylene glycol under atmosphere pressure

Direct amination of aryl iodides and bromides with ammonia under 1 atm pressure has been effected using in situ‐generated hemilabile coordinated copper(I) species from copper(I) halides or copper metal in aqueous ethylene glycol, producing primary aromatic amines in good yields. Ammonia pressure and water were found to accelerate the copper‐mediated reaction while strong chelating ligands showed a suppression effect. A rationale for the copper‐mediated amination of aryl halides with ammonia is given based on a double‐face role of chelating effect. Copyright © 2009 John Wiley & Sons, Ltd.     

Selective Monoarylation of Primary Amines Using the Pd‐PEPPSI‐IPentCl Precatalyst

A single set of reaction conditions for the palladium‐catalyzed amination of a wide variety of (hetero)aryl halides using primary alkyl amines has been developed. By combining the exceptionally high reactivity of the Pd‐PEPPSI‐IPent^Cl catalyst (PEPPSI=pyridine enhanced precatalyst preparation, stabilization, and initiation) with the soluble and nonaggressive sodium salt of BHT (BHT=2,6‐di‐tert‐butyl‐hydroxytoluene), both six‐ and five‐membered (hetero)aryl halides undergo efficient and selective amination.     

An inexpensive cyclodiphosphazane as an efficient ligand for the palladium-catalyzed amination of aryl bromides and chlorides

An economic and novel ligand, cyclodiphosphazane [ClPN(t-Bu)]₂ (1), was introduced in the palladium-catalyzed amination of unactivated aryl halides. The catalyst allows for the amination of aryl chlorides and bromides with secondary cyclic amines and anilines in good yields.