氯化钯在氟化四丁基铵中当场生成纳米钯：一种高效、可回收的催化体系，在无配体和无溶剂条件下催化Suzuki-Miyaura反应

氯化钯在氟化四丁基铵中当场生成纳米钯,该钯催化剂在Suzuki-Miyaura交叉偶联反应中显示很高的催化效率。在氯化钯和氟化四丁基铵存在下,许多芳基卤代烃可以顺利与芳基硼酸发生偶联反应,得到中等到高的产率。此外,在Suzuki-Miyaura偶联反应中该氯化钯/氟化四丁基铵催化体系可以回收重复使用多次,并且芳基溴代烃可以在15-60分钟内反应完全。值得指出的是,该反应是在无溶剂、无配体和催化体系可回收重复使用的条件下进行的。这和无配体条件下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。该氯化钯/氟化四丁基铵催化反应的反应机理也进行了讨论。     

无配体Pd(Ⅱ)-催化的Suzuki交叉偶联反应中自身偶联的抑制

PdCl₂/i-PrOH体系能够高效地催化卤代芳烃与芳基硼酸的交叉偶联反应，高收率地得到交叉偶联的产物(80-99%)，并且能有效地抑制芳基硼酸的自身偶联反应。     

醚功能化的膦配体的合成、负载及其在钯催化的Suzuki-Miyaura反应中的应用

合成了一种新的醚功能化的二茂铁膦3,连到Merrifield树脂上形成负载型的膦配体4;分别开展了膦配体3及其负载型的4在钯催化的Suzuki-Miyaura偶联反应中催化研究;发现相应形成的均相和多相钯催化剂可高产率地催化一系列的溴代芳烃与芳基硼酸偶联形成相应的联芳烃,以及负载型催化剂在不补加钯时具有一定的循环性能.     

纳米钯/[BDABCO]Br/H_2O体系催化的Suzuki反应

采用水为反应介质,在溴化1-丁基-4-氮杂-1-氮鎓双环[2.2.2]辛烷([BDABCO]Br)存在下,纳米钯能有效地催化一系列卤代芳烃与芳基硼酸发生Suzuki交叉偶联反应,以良好产率生成联苯类产物。该催化体系nano-Pd/[BDABCO]Br/H2O对底物官能团无影响,产物可通过简单萃取分离,产率优良,对环境友好。     

浅谈国外“Suzuki-Miyaura金属偶联反应”的教学设计思路

Suzuki-Miyaura金属偶联反应是在零价钯配合物的催化下,芳基硼酸或硼酸酯与卤代芳烃发生交叉偶联的过程。该反应具有很强的底物适应性和官能团容忍性,广泛应用于众多天然产物与有机材料的合成。鉴于反应的重要性,近年来国外高校逐渐尝试将Suzuki-Miyaura反应引入到本科生的有机实验教学中。本文针对2000年后Journal of Chemical Education期刊中涉及的Suzuki-Miyaura反应,分别从反应条件、后处理和表征方法、实验拓展等多个方面进行了比较和归纳,并对其设计理念和教学特色进行了综述。     

氧官能化的膦配体在钯催化的Suzuki-Miyaura反应中的应用

合成了带甲氧基和羟基官能团的二茂铁膦配体, 评价了它们在钯催化的Suzuki-Miyaura偶联反应中的性能, 发现带甲氧基的膦配体对钯催化的Suzuki-Miyaura偶联反应有更好的性能, 可催化富电子溴代芳烃和缺电子氯代芳烃与苯硼酸反应高产率地生成相应的联芳烃产物.     

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/碳高效绿色催化Suzuki交叉偶联反应

开发了一个以钯/碳为催化剂高效绿色催化Suzuki反应制备联苯类化合物的新方法.该体系以环境友好的聚乙二醇400的水溶液为反应溶剂,加入离子液体1-甲基-3-丁基咪唑双三氟甲磺酰亚胺盐,可高效催化溴代芳烃与芳基硼酸的Suzuki交叉偶联反应,并且催化剂可以循环利用4次而催化效率没有明显降低.     

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.     

低温Suzuki反应合成联苯及三联苯化合物

发展了一个低温下无配体钯催化溴代芳烃与芳基硼酸的Suzuki反应体系。该体系以醋酸钯为催化剂,无水碳酸钾为碱,乙醇水溶液为溶剂,无需加入任何配体,在0oC下即可高效催化溴代芳烃与芳基硼酸的Suzuki反应;反应的底物容忍性好,产品分离收率最高达97%。以溴代芳基N-甲基亚氨基二乙酸硼酸酯为砌块分子,通过调控反应温度,实现了砌块分子选择性Suzuki反应,从而一锅合成了不对称三联苯化合物,产品收率最高为81%。     

Preparations of Saturated N‐P‐N Type Secondary Phosphine Oxides and their Applications in Cross‐Coupling Reactions

A series of cyclohexane‐1,2‐diamine ( 3a – 3d ) and benzene‐1,2‐diamine derivatives ( 3e – 3h ) were pre‐ pared. Followed by hydrolysis, the reaction of 3a – 3c with PCl₃ successfully led to the formation of cor‐ responding metastable saturated heteroatom‐substituted secondary phosphine oxides (HASPO 4a – 4c ), a tautomer of the saturated heteroatom‐substituted phosphinous acid (HAPA). Whereas ambient‐stable diamine‐coordinated palladium complexes were obtained, HAPA‐coordinated palladium complexes were not successfully synthesized. The molecular structures of HASPO 4c , Pd(OAc)₂(3a) , PdBr₂(3b) and Pd(OAc)₂(3c) and [Cu(NO₃)(3d)⁺][NO₃ ^? ] were determined by single‐crystal X‐ray diffraction method. Catalysis of in‐situ Suzuki‐Miyaura cross‐coupling reactions for aryl bromides and phenylboronic acid using diamine 3a as ancillary ligand showed that the optimized reaction condition at 60 °C is the combination of 2 mmol % 3a /3.0 mmol KOH/1.0 mL 1,4‐dioxane/1 mmol % Pd(OAc)₂. Moreover, moderate reactivity was observed when using aryl chlorides as substrates (supporting infor‐ mation). When diamine 3d was employed in Heck reaction, good tolerance of functional groups of aryl bromides were observed while using 4‐bromoanisole and styrene as substrates. The optimized condi‐ tion for Heck reaction at 100 °C is 3 mmol % 3d /3.0 mmol CsF/1.0 mL toluene/3 mmol % Pd(OAc)₂. In general, cyclohexane‐1,2‐diamine derivatives exhibited better catalytic properties than those of benzene‐1,2‐diamines.     

Ferrocenyl bisoxazoline as an efficient non‐phosphorus ligand for palladium‐catalyzed copper‐free Sonogashira reaction in aqueous solution

Pd(OAc)₂‐catalyzed Sonogashira coupling reactions of alkynes and a variety of aryl halides with 1,3‐bis(5‐ferrocenylisoxazoline‐3‐yl)benzene as an efficient non‐phosphorus ligand under copper‐free conditions are presented. The main advantages over previous methodologies include low catalyst loading (0.2 mol% Pd(OAc)₂ and 0.4 mol% ferrocenyl bisoxazoline ligand are sufficient for these coupling reactions), less problematic reaction medium (water–dimethylformamide) and more convenient operation (no requirement for nitrogen protection).     

Palladium‐catalyzed cyclization of β‐bromo‐α,β‐unsaturated ketones with arylhydrazines leading to 3‐substituted 1‐aryl‐1 H‐pyrazoles

β‐Bromo‐α,β‐unsaturated ketones are condensed with arylhydrazines to form hydrazones, which are in situ intramolecularly cyclized into 3‐substituted 1‐aryl‐1 H‐pyrazoles under a catalytic system of Pd(OAc)₂/1,3‐bis(diphenylhosphino)propane (dppp)/NaO^tBu. Copyright © 2012 John Wiley & Sons, Ltd.     

Palladium‐Catalyzed Direct C2 Arylation of N‐Substituted Indoles with 1‐Aryltriazenes

A novel and efficient palladium‐catalyzed C2 arylation of N‐substituted indoles with 1‐aryltriazenes for the synthesis of 2‐arylindoles was developed. In the presence of BF₃ ? OEt₂ and palladium(II) acetate (Pd(OAc)₂), N‐substituted indoles reacted with 1‐aryltriazenes in N,N‐dimethylacetamide (DMAC) to afford the corresponding aryl–indole‐type products in good to excellent yields.     

Synthesis of regioregular poly(3‐octylthiophene)s via Suzuki polycondensation and end‐group analysis by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

Regioregular poly(3‐octylthiophene)s were synthesized through a palladium‐catalyzed Suzuki polycondensation of 2‐(5‐iodo‐4‐octyl‐2‐thienyl)‐4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolane. The effects of the palladium catalyst {tetrakis(triphenylphosphine)palladium(0) [Pd(PPh₃)₄], palladium(II) acetate [Pd(OAc)₂], [1, 1′‐bis(diphenylphosphino)ferrocene]dichloropalladium(II) [Pd(dppf)Cl₂], tris(dibenzylideneacetone)dipalladium(0), or bis(triphenylphosphine)palladium(II) dichloride [Pd(PPh₃)₂Cl₂]} and the reaction conditions (bases and solvents) were investigated. NMR spectroscopy revealed that poly(3‐octylthiophene)s prepared via this route were essentially regioregular. According to size exclusion chromatography, the highest molecular weights were obtained with in situ generated Pd(PPh₃)₄ and tetrakis(tri‐o‐tolylphosphine]palladium(0) {Pd[P(o‐Tol)₃]₄} catalysts or more reactive, phosphine‐free Pd(OAc)₂. Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry was used to analyze end groups and allowed the determination of some mechanistic aspects of the Suzuki polycondensation. The polymers were commonly terminated with hydrogen or iodine as a result of deboronation and some deiodination. Pd(PPh₃)₄, Pd(PPh₃)₂Cl₂, and Pd[P(o‐Tol)₃]₄ induced aryl–aryl exchange reactions with the palladium center and resulted in some chains having phenyl‐ and o‐tolyl‐capped chain ends. Pd(dppf)Cl₂ yielded only one type of chain, and it had hydrogen end groups. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1454–1462, 2005     

Ligand‐free palladium‐catalyzed tandem pathways for the synthesis of 4,4‐diarylbutanones and 4,4‐diaryl‐3‐butenones under microwave conditions

Two efficient Pd‐catalyzed tandem pathways for the synthesis of 4,4‐diaryl‐2‐butanones and 4,4‐diaryl‐3‐buten‐2‐ones were elaborated. The first step in both procedures was the Heck coupling of methyl vinyl ketone (MVK) and various aryl iodides leading to 4‐aryl‐3‐buten‐2‐one with the yield of up to 92% in 1 hr. The second step performed with the same catalyst and a new portion of aryl iodide in the presence K₂CO₃ as a base produced 4,4‐diaryl‐3‐buten‐2‐ones in high yield. Reaction selectivity changed completely to saturated 4,4‐diaryl‐2‐butanones, reductive Heck products, when a tertiary amine was used instead of K₂CO₃. Due to the application of microwave irradiation (MW), the desired products were obtained in high yield in a short time (4 hr), using 0.5 mol% of the Pd (OAc)₂ catalyst without additional ligands.     

Palladium‐catalysed Suzuki reaction of aryl chlorides in aqueous media using 1,3‐dialkylimidazolidin‐2‐ylidene ligands

A highly effective, easy to handle and environmentally benign process for palladium‐mediated Suzuki cross‐coupling is developed. The in situ prepared three‐component system Pd(OAc)₂–1,3‐bis(alkyl)imidazolinium chlorides (2a–f) and Cs₂CO₃ catalyses quantitatively the Suzuki cross‐coupling of deactivated aryl chlorides. Copyright © 2005 John Wiley & Sons, Ltd.     

Cavity‐Shaped Ligands: Calix[4]arene‐Based Monophosphanes for Fast Suzuki–Miyaura Cross‐Coupling

Five conical calix[4]arenes that have a PPh₂ group as the sole functional group anchored at their upper rim were assessed in palladium‐catalysed cross‐coupling reactions of phenylboronic acid with aryl halides (dioxane, 100 °C, NaH). With arylbromides, remarkably high activities were obtained with the catalytic systems remaining stable for several days. The performance of the ligands is comparable to a Buchwald‐type triarylphosphane, namely, (2′‐methyl[1,1′‐biphenyl]‐2‐yl)diphenylphosphane, which in contrast to the calixarenyl phosphanes tested may display chelating behaviour in solution. With the fastest ligand, 5‐diphenylphosphanyl‐25,26,27,28‐tetra(p‐methoxy)benzyloxy‐calix[4]arene ( 8 ), the reaction turnover frequency for the arylation of 4‐bromotoluene was 321 000 versus 214 000 mol(ArBr).mol(Pd)^?1. h^?1 for the reference ligand. The calixarene ligands were also efficient in Suzuki cross‐coupling reactions with aryl chlorides. Thus, by using 1 mol % of [Pd(OAc)₂] associated with one of the phosphanes, full conversion of the deactivated arenes 4‐chloroanisole and 4‐chlorotoluene was observed after 16 h. The high performance of the calixarenyl–phosphanes in Suzuki–Miyaura coupling of aryl bromides possibly relies on their ability to stabilise a monoligand [Pd⁰L(ArBr)] species through supramolecular binding of the Pd‐bound arene inside the calixarene cavity.     

Short communication: An alternative and effective catalyst in the stereo‐specific reaction of Z‐1‐aryl‐1‐stannyl‐2‐silylethenes with allyl bromide

The Pd(dba)₂‐catalyzed reaction of Z‐1‐aryl‐1‐(tributylstannyl)‐2‐(trimethylsilyl)ethenes with allyl bromide in the presence of copper(I) iodide is reported for the first time. The reaction in the presence of 0.5 mol% Pd(dba)₂ and 8 mol% CuI in dimethylformamide takes place at room temperature to give E‐2‐aryl‐1‐(trimethylsilyl)penta‐1,4‐dienes exclusively in isolated yields of 62–99%. A putative reaction mechanism is proposed. Copyright © 2005 John Wiley & Sons, Ltd.     

Pd(OAc)2@SBA‐15/PrEn nanoreactor: a highly active,reusable and selective phosphine‐free catalyst for Suzuki–Miyaura cross‐coupling reaction in aqueous media

A series of ordered mesoporous organic–inorganic hybrid material was designed by using the amine‐functionalized SBA‐15 (PdX₂@SBA‐15/N_Y, Y = 1, 2) as solid support for palladium complexes. Among them, the Pd(OAc)₂/ethylenediamine complex encapsulated into SBA‐15 (Pd(OAc)₂@SBA‐15/PrEn or Pd(OAc)₂@SBA‐15/PrNHEtNH₂) exhibits higher activity and selectivity toward Suzuki cross‐coupling reaction under aerobic conditions and water solvent mixture. The SBA‐15/PrEn supported palladium pre‐catalyst could be separated easily from reaction products and used repetitively several times, showing its superiority over homogeneous catalysts for industrial and chemical applications. Copyright © 2013 John Wiley & Sons, Ltd.