Pd-NHC络合物催化交叉偶联反应的新进展

钯催化的交叉偶联反应能非常有效且方便构建碳-碳键并应用于农药、医药、新型材料和有机中间体等领域.多年来,各种不同结构的配体以及新型的催化体系被不断开发出来.其中N-杂环卡宾(NHC)配体毒性低,稳定性好,同时在反应过程中具备良好的配位能力,因而被作为新一代催化体系应用于各种不同的交叉偶联反应中.根据NHC结构特点综述了近年来新开发的Pd-NHC催化剂及其在多种交叉偶联反应中的应用.     

1,2-二苯基乙烯基膦钯(Ⅱ)催化的 Sonograshira交叉偶联反应

合成了含有大位阻和富电子膦配体的1,2-二苯基乙烯基膦配体, 并研究了以1,2-二苯基乙烯基膦配体和二氯化二苯腈合钯(Ⅱ)为催化剂催化的Sonograshira交叉偶联反应.     

Complex Pd( Ⅱ ) with Vinyiphosphine and Its Application in Sonograshira Cross Coupling Reaction

合成了含有大位阻和富电子膦配体的1,2-二苯基乙烯基膦配体,并研究了以1,2-二苯基乙烯基膦配体和二氯化二苯腈合钯(Ⅱ)为催化剂催化的Sonograshira交叉偶联反应.     

环钯化合物在Heck反应中的应用研究

钯催化交叉偶联反应在化学工业、合成天然产物及生物活性物质中有着广泛的应用.催化剂体系是交叉偶联反应研究的核心.环钯化合物结构简单、性能稳定,在催化交叉偶联反应中具有高活性、高选择性,引起研究者们的极大关注,不断有新的环钯化合物被合成出来,其催化性能也得到了研究.本文综述了环钯化合物的合成方法及其在Heck反应中的应用.     

环钯化合物在Heck反应中的应用研究

钯催化交叉偶联反应在化学工业、合成天然产物及生物活性物质中有着广泛的应用.催化剂体系是交叉偶联反应研究的核心.环钯化合物结构简单、性能稳定,在催化交叉偶联反应中具有高活性、高选择性,引起研究者们的极大关注,不断有新的环钯化合物被合成出来,其催化性能也得到了研究.本文综述了环钯化合物的合成方法及其在Heck反应中的应用.     

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.     

镍N-杂环卡宾配合物在均相催化偶联反应中的应用

 近十几年来, N-杂环卡宾的配位化学和金属有机化学发展迅速, 已成为均相催化反应中研究最为广泛的配体之一. 在许多过渡金属催化的有机合成反应中特别是偶联反应中, N-杂环卡宾与传统有机膦配体相比具有较高的反应性. 镍价格低廉, 在很多反应中有望替代贵金属钯催化剂. 本文总结了镍 N-杂环卡宾化合物在催化交叉偶联反应和还原偶联反应中的最新应用进展.     

新型氮杂环卡宾-钯配合物的设计、制备及在Buchwald-Hartwig交叉偶联反应中的应用

发展了一类含有不同亚胺配体的氮杂环卡宾-钯配合物,并将其应用到Buchwald-Hartwig交叉偶联反应中.研究发现亚胺配体的结构对催化活性有明显的影响,尤其带有强吸电子基团的亚胺配体表现最佳.利用该类配合物可以在低至0.5 mol%的催化剂用量下实现不同氯代芳烃和各种胺的高效偶联反应.     

二价钯催化的α或β联烯胺与烯丙基溴的偶联环化反应的研究

官能团化的联烯在过渡金属钯物种催化下的偶联环化反应作为一种有效的合成含氮、氧杂环的方法已经受到越来越多的重视[1].但是,联烯胺与烯丙基溴的偶联环化反应还没有被深入的研究过.我们组对钯催化下联烯醇与烯丙基溴的反应进行了一些研究[2],并基于此进行了联烯胺与烯丙基溴的偶联环化反应的研究.我们经过研究发现,可以通过二价钯催化,高效地经由α或β联烯胺与烯丙基溴的反应得到2,5-二氢吡咯或1,2,3,6-四氢吡啶类化合物,并且经过研究证明反应是通过二价钯的催化循环历程进行的.     

氮、硫双齿配体钯促进的Suzuki-Miyaura交叉偶联反应

钯配合物促进的Suzuki-Miyaura交叉偶联反应为构建碳-碳骨架的重要方法,主要用于药物化学、天然产物、材料学及超分子配体等领域。以2-噻吩甲醛、脂肪族/芳香族伯胺、取代肼及羟胺等为原料,合成了9种2-噻吩甲醛亚胺类N,S-双齿配体（3a~3i）,其结构经¹H NMR, ¹³C NMR和HR-MS（APCI）表征。并以N-环己基-2-噻吩甲亚胺(3b)为例,研究了配体对钯促进的Suzuki-Miyaura交叉偶联反应的催化性能。结果表明：在反应体系Pd(OAc)₂/3b/Cs₂CO₃/DMF中,苯硼酸与芳溴的交叉偶联反应的分离产率达到95%。     

Palladium-catalyzed cross coupling reaction of N-alkoxyimidoyl bromides and its application to one-pot synthesis of N-arylamines

The synthetic utility of N-alkoxyimidoyl halides is demonstrated using the palladium-catalyzed cross-coupling reaction. The Sonogashira and Suzuki-Miyaura coupling reactions of N-alkoxyimidoyl bromides produced versatile ketoxime ethers in good to excellent yields. A one-pot reaction of the imidoyl bromides with arylboronic acid and allylmagnesium bromide to produce N-arylamines via Suzuki-Miyaura coupling followed by domino reaction involving sequential addition-eliminative rearrangement-addition reactions was developed.     

Convergent stereoselective synthesis of the visual pigment A2E

[chemical reaction: see text]. A stereoselective total synthesis of the visual pigment A2E has been achieved with use of palladium-catalyzed cross-coupling reactions in all key steps: a regioselective Suzuki or Negishi coupling of 2,4-dibromopyridine, a Sonogashira reaction, and a double Stille cross-coupling to complete the bispolyenyl skeleton.     

Recent advances in theoretical studies on ligand-controlled selectivity of nickel-and palladium-catalyzed cross-coupling reactions

Nickel-and palladium-catalyzed cross-coupling reactions have attracted wide attentions,while ligandcontrolled selectivity in these reactions are still elusive,and calculations can help obtain possible catalytic cycles to generate different products and provide insights into key factors of selectivity,which facilitates the development of new catalyst systems to control reaction selectivity.This review covers our efforts and some significant achievements from other groups on ligand-controlled reaction selectivity of coupling reactions,including introduction,computational methods,selectivity control by ligands in Niand Pd-catalyzed coupling reactions,as well as summary and future perspectives.     

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.     

A formal total synthesis of the telomerase inhibitor dictyodendrin B

A formal synthesis of the telomerase inhibitory marine pyrrolocarbazole alkaloid dictyodendrin B is described. The key features are consecutive palladium-catalyzed cross-coupling reactions and intramolecular reductive coupling reaction to construct the pyrrolo[2,3-c]carbazole framework.     

Palladium-catalyzed cross-coupling reactions of aryl mesylates

Palladium-catalyzed cross-coupling reactions are state-of-the art methods for synthesis of many important compounds. The development of the use of the phenol-derived sulfonated hydroxyl group in the coupling reactions is highly attractive as the hydroxyl group is commonly present in organic compounds and they are versatile alternatives to aryl halides in cross-coupling reactions. In this tutorial review, we summarize the current development of palladium-catalyzed cross-coupling reactions of aryl mesylates.     

Phosphine-free Suzuki cross-coupling reaction: a mild and selective method for the carbon–carbon bond formation in aqueous tea extract

A mild and selective protocol has been developed for the palladium-catalyzed phosphine-free Suzuki cross-coupling reaction of aryl bromides with arylboronic acids in aqueous tea extract at room temperature. It is noteworthy that the aqueous tea extract plays an important role in the reaction, and various functional groups are tolerated under the optimized conditions. The reactions proceeded with very good chemoselectivity in favor of the bromo instead of the chloro group even at higher temperatures. Furthermore, this protocol could be applied to the cross-coupling of 4-bromoindole without protecting the base sensitive amine group with arylboronic acids in moderate to excellent yields.     

l-Arginine as a base and ligand for the palladium-catalyzed C-C and C-N cross-coupling reactions in aqueous media

l-Arginine (2-amino-5-guanidinopentanoic acid) acts as a base and ligand in reaction medium, exhibits a very high activity and recyclability to palladium-catalyzed C-C and C-N cross-coupling reactions in aqueous media. The corresponding Suzuki products were obtained in good to excellent yields by using various aryl halides (I, Br, Cl). Also, the cross coupling reactions of arylboronic acids with various amines in aqueous medium proceed in good to excellent yield under same conditions. Furthermore, the catalyst could be easily separated from the reaction mixture and could be recycled several times without significant loss in its catalytic activity.     

Pd-catalyzed regiocontrolled Sonogashira and Suzuki cross-coupling reaction of 3,6-dihalogenoimidazo[1,2-a]pyridines: one-pot double-coupling approach

New and efficient regioselective Sonogashira and Suzuki-Miyaura palladium-catalyzed coupling reactions of 3,6-dihalogenoimidazo[1,2-a]pyridines followed by another cross-coupling has been successfully developed. Various solvents, palladium species and bases were tested. Scope and limitations of this regiocontrolled palladium-catalyzed reaction were investigated. The synthesis of 3,6-disubstituted imidazo[1,2-a]pyridine derivatives using one-pot regioselective double-coupling approach was developed. This procedure affords convergent syntheses of polysubstituted compounds in high yields in a very few steps.     

Suzuki-Miyaura cross-coupling reactions of potassium alkenyltrifluoroborates

We have previously reported that the palladium-catalyzed cross-coupling reaction of air-stable potassium alkenyltrifluoroborates with aryl halides and triflates proceeds readily with good yields. Recent progress in outlining the scope and limitations of such reactions is described herein. The palladium-catalyzed cross-coupling reaction of potassium alkenyltrifluoroborates with aryl and heteroaryl halides and triflates proceeds readily with moderate to excellent yields. The alkenyl cross-coupling reaction can generally be effected using 2 mol % of PdCl2(dppf).CH2Cl2 as catalyst in i-PrOH-H2O in the presence of t-BuNH2 as the base. A variety of functional groups are tolerated in both partners, and the process is stereospecific with regard to the alkenyltrifluoroborate starting material.