分子内不对称Heck型反应研究进展

近年来，过渡金属催化分子内不对称Heck型反应取得了重要研究进展。在一些新型催化体系条件下，通过分子内的不对称Heck型反应使得一系列含有叔碳或者季碳的并环和螺环化合物得以高效合成。综述了分子内不对称简单烯烃Heck反应、去芳构化Heck反应和还原Heck反应的研究进展。     

钯催化的芳基亚磺酸钠的脱硫Heck偶联反应

采用六氟锑酸银为添加剂,实现了钯催化的芳基亚磺酸钠与丙烯酸酯在弱极性溶剂中通过脱硫Heck偶联反应合成肉桂酸酯类化合物.通过核磁共振氢谱、核磁共振碳谱和高分辨质谱对产物进行了结构表征.结果表明,六氟锑酸银活化了钯催化剂,促进了甲苯中芳基亚磺酸钠与丙烯酸酯的脱硫Heck偶联反应;在空气氛围下的产物收率比在氧气和氮气氛围下的产物收率高.通过反应机理分析发现,氧气不利于三苯基膦配体参与的钯催化剂的再生过程,但有利于醋酸铜氧化剂的再生过程.     

Dppc~+PF_6~-Pd(dba)_2催化的水相中的Heck偶联反应

研究了二茂钴阳离子双膦配体Dppc+PF6-催化的纯水中Heck反应的活性。结果表明Dppc+PF6-与Pd(dba)2形成的催化剂,以三乙胺为碱,在120℃反应2个或4个小时能够有效地催化不同碘代芳烃与不同烯烃的Heck偶联反应。该催化体系操作和后处理简单,通过乙醚萃取就可以很容易实现催化剂与底物的分离。     

关于Heck反应的研究

研究了钯催化的双Heck反应,筛选出了Cs2CO3/DMF/ PPh3/Pd(OAc)2催化体系.该体系可以很好地催化碘苯与丙烯酸酯的反应,环境友好,后处理简单等优点,这些特点对实现工业化是很有利的.     

不对称Heck反应研究进展

介绍了Heck反应及其基本催化过程。从分子内、分子间两方面综述了不对称Heck反应的重要发展历程和研究进展。     

非钯催化剂在Heck偶联反应中的应用研究进展

钯催化的Heck偶联反应是过渡金属催化的构建C—C的重要途径之一,在有机合成中有着广泛的应用。钯是Heck偶联反应的有效催化剂,但其存在价格昂贵、毒性高、对环境要求苛刻等缺点。化学工作者发现镍、铜、钴、铁等非钯廉价金属对Heck偶联反应也有一定的催化活性。综述了近年来非钯催化剂如镍、铜、钴及其它金属催化剂在Heck偶联反应中的应用研究进展。     

5-(3-甲基-1-氢-吲哚)乙酸的合成研究

以2-(3-溴苯基)乙酸为原料,经过酯化、硝化、还原、取代、Heck反应和酯水解反应成功合成了标题化合物,总收率18.62%。关键步骤是取代反应和Heck反应。该方法操作简单、成本低、收率高,适合于工业化生产。     

活性炭固载膦钯化合物的制备及其在Heck反应中的催化性能研究

采用硝酸对活性炭进行氧化,增加活性炭上羧基的含量,再与乙二胺反应,在活性炭上引入氨基,然后与氯代二苯基膦反应,将膦配体引入活性炭上,并以此为载体制得活性炭固载的膦钯化合物。采用傅里叶变换红外(FTIR)光谱、X射线光电子能谱(XPS)和透射电镜(TEM)手段对其进行表征,并研究了该催化剂对Heck反应的催化性能。实验结果表明,催化剂中钯通过配位键固定在载体上,在载体表面均匀分布,该催化剂对碘代芳烃和烯烃的Heck反应具有较高的催化活性,并具有良好的循环使用性能。     

分子内还原Heck反应合成7-溴-1-茚满酮

研究了标题化合物的合成新方法,即以邻溴苯甲酸为原料,经取代反应、氧化还原反应、格氏反应以及分子内还原Heck反应合成了目标化合物。探讨了分子内还原Heck反应中反应溶剂、反应温度、反应时间及催化剂种类等条件对产率的影响。最终确定了以四氢呋喃为溶剂、Pd(dppf)Cl_2为催化剂、60℃反应6 h的最佳反应条件,产率可达83%。     

纳米Pd催化Heck偶联的最新研究进展

Heck反应是一类重要的C—C偶联反应,纳米钯催化的Heck偶联反应因其高效率和好的结果,且催化剂容易回收再用等优点,一直受到许多科学工作者的关注。总结了最近几年纳米钯催化剂在Heck反应中的最新应用研究进展。     

Structures and antitumor activities of planar chiral cyclopalladated ferrocene derivatives

Bis(μ-acetato)-bridged planar chiral cyclopalladated products have been obtained by asymmetric cyclopalladation of the corresponding chiral ferrocenylimines with palladium(II) acetate and sodium acetate in methanol at room temperature. Two diastereomers were isolated in enantiomerically pure form and their absolute configurations have been determined by single-crystal X-ray analysis. It was found that enantiomerically pure cyclopalladated ferrocene displayed the excellent inhibition to two human breast carcinoma cell lines, MDA-MB-231 and MDA-MB-468 and could have good application prospect in pharmaceutical use.     

Aqueous Heck Arylation of Acrolein Derivatives: The Role of Cyclodextrin as Additive

Heck arylation of acrolein dialkyl acetal with (hetero)-aryl halides in water catalyzed by solid palladium catalysts and in presence of cyclodextrins is reported. Depending on the nature of the base, either cinnamaldehyde or 3-aryl propionic ester is obtained. It was shown that the presence of cyclodextrins in the reaction media increased the reaction rate as well as the stability of the palladium species.     

Aqueous Heck Arylation of Acrolein Derivatives: The Role of Cyclodextrin as Additive

Heck arylation of acrolein dialkyl acetal with (hetero)-aryl halides in water catalyzed by solid palladium catalysts and in presence of cyclodextrins is reported. Depending on the nature of the base, either cinnamaldehyde or 3-aryl propionic ester is obtained. It was shown that the presence of cyclodextrins in the reaction media increased the reaction rate as well as the stability of the palladium species.

     

Synthesis of condensation polymers catalyzed by palladium-graphite

Palladium-graphite (Pd---Gr) was applied to polycondensations as a heterogeneous palladium catalyst. Catalytic activities of Pd---Gr for the Heck reaction and a carbonyl insertion reaction were investigated using the model reactions. Polycinnamamide was synthesized through the Heck reaction of N, N′-(3,4′-oxydiphenylene)bis(acrylamide) and bis(4-iodophenyl) ether catalyzed by Pd---Gr. The polymerization proceeded efficiently in the presence of tributylamine, but required a long reaction time compared with the case of homogeneous catalysts. The resulting polymer was almost white in color, which means that it was less contaminated by palladium metal. The removal and recycling of Pd---Gr were much easier than the case of homogeneous catalysts. Aramid was also synthesized through the carbonyl insertion reaction of m-diiodobenzene and bis(4-aminophenyl) ether catalyzed by Pd---Gr. The rate of carbon monoxide consumption for the polymerization catalyzed by Pd---Gr was almost equal to that catalyzed by the homogeneous palladium catalyst. In both cases, the structures of the resulting polymers were identical to those prepared by homogeneous palladium catalysts.     

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。     

Structural Effect of Pincer Pd(II)–ONO Complexes Modified with Acylthiourea on Sizes of the In Situ Generated Pd Nanoparticles During Heck Coupling Reaction

Catalysis Letters - The Pd nanoparticles generated in situ from Pd–pincer complexes catalyzed Heck coupling reaction. For this purpose, new Pd(II)–ONO pincer complexes (1–4)...     

Imidazole and Imidazoline Derivatives as N‐Donor Ligands for Palladium‐Catalyzed Mizoroki–Heck Reaction

Imidazole and imidazoline (dihydroimidazole) derivatives can serve as efficient and simple ligands for the palladium‐catalyzed Mizoroki–Heck reaction. Among the imidazole and imidazoline derivatives in our investigations, the 2‐methylimidazoline‐palladium(II) chloride complex exhibited the highest catalytic activity.     

氯代芳烃偶联反应中钯催化剂的研究进展

在合适的钯催化作用下,可将廉价易得、低活性的氯代芳烃应用于C—C键和C杂键形成的偶联反应。对偶联反应用钯催化剂的研究进行了综述。通过选择合适的配体,钯催化剂可有效地催化带有多种体取代基的氯代芳烃或氯代杂芳烃,发生Suzuki、Negishi、Stille和Heck等多种偶联反应,获得较高的收率和很高的选择性。     

Ferrocenylimidazoline palladacycles: Syntheses,crystal structures and applications as catalysts for Suzuki cross coupling reaction in water

The air and moisture stable triphenylphosphine (PPh₃) adducts of cyclopalladated ferrocenylimidazoline complexes 2a and 2b have been synthesized and structurally characterized by single crystal X-ray diffraction. The catalytic studies on 2a and 2b indicate that they are effective catalysts for the Suzuki reaction of activated aryl chlorides with phenylboronic acid in neat water under air atmosphere.