NHC-Ag修饰的钐配合物催化CO2与端炔的羧化反应

将1,3-二(4-羧基苯甲基)-苯并咪唑鎓氯化物（H2BCBI）与硝酸钐在水热条件下进行反应,得到二维配位聚合物[Sm(BCBI)(NO3)2·H2O]n（Sm-BCBI）,将其与AgOAc作用引入NHC-Ag(I)催化位点,制备了氮杂环卡宾-银功能化的钐配合物（NHC-Ag(I)@Sm-BCBI）。通过单晶X-射线衍射、PXRD、TGA、XPS、ICP-OES、SEM和EDS等对Sm-BCBI和NHC-Ag(I)@Sm-BCBI进行表征。结果表明,Sm-BCBI为二维层状结构;NHC-Ag(I)@Sm-BCBI催化剂具有良好的热稳定性,且催化剂中的银以+1价形式存在。将NHC-Ag(I)@Sm-BCBI用于催化CO2（0.1 MPa）与苯乙炔的羧化反应,在反应温度为50 ℃,以Cs2CO3为碱,DMF为溶剂,催化剂用量为70 mg（0.35 mol%）,反应时间为16 h的最佳反应条件下,苯丙炔酸分离产率可达80%。且催化剂容易回收,在循环使用4次以后,催化产率仍能达到60%。     

银催化的端炔羧化偶联合成2-炔酸酯

在有机合成中间体中,2-炔酸酯是一类重要的合成子。尽管这些化合物在化学合成中十分重要,但迄今为止却很少报道其合成方法。近年来,在发展末端炔烃羧化偶联、卤代烃、和二氧化碳制备2-炔酸酯衍生物方面已经取得了很大的进展。除了良好的产量,该反应还具有优秀的原子经济和步骤经济性以及底物的易获得性等优点。本文主要综述了通过末端炔烃、卤代烃和CO2的三组分羧化偶联反应来制备2-炔酸酯衍生物的合成方法的研究进展。     

9-炔十八酸的合成

将植物油经醇解、精馏制得油酸甲酯,然后加成、消除、水解制得9-炔十八酸粗品,最后重结晶得成品。成品熔点48℃,纯度可达98.5%以上。     

炔草酯的合成工艺研究

研究了以R-(+)-2-(4-羟基苯氧基)丙酸、氯丙炔、2,3-二氟-5-氯吡啶为原料,经由R-(+)-2-(4-羟基苯氧基)丙酸炔丙酯制备炔草酯的合成工艺,并讨论了溶剂、反应时间、反应温度对合成目标产物的影响。结果表明,以DMF为溶剂,碳酸钾为缚酸剂,在80℃左右条件下,R-(+)-2-(4-羟基苯氧基)丙酸与氯丙炔反应6 h,再升温到95℃左右,滴加2,3-二氟-5-氯吡啶反应10 h,过滤、重结晶得到炔草酯,收率达到89%,光学纯度为99%。     

氯化钯催化偶联反应合成对-三联苯

用苯基格氏试剂与硼酸三正丁酯在室温下反应制得苯基硼酸,以苯基硼酸与对二溴苯为原料,以氯化钯为催化剂,以四丁基碘化铵为相转移催化剂及在碳酸钾的参与下,在水／苯为介质的非均相体系中进行偶联反应,合成了对 三联苯,产率达７０％（以对二溴苯计）。物料摩尔配比为：对二溴苯∶苯基硼酸∶氯化钯∶四丁基碘化铵∶碳酸钾＝１∶２．２∶０．０１∶１∶５。     

氯化氢酸解2-膦酸丁烷-1,2,4-三羧酸五甲酯反应动力学

在可无级调速的玻璃搅拌釜气液相反应器中,系统地研究了不同温度下用氯化氢干气酸解2-膦酸丁烷-1,2,4-三羧酸五甲酯的反应动力学,以开发制备2-膦酸丁烷-1,2,4-三羧酸(PBTCA)的绿色工艺。采用1级串联反应动力学方程拟合2-膦酸丁烷-1,2,4-三羧酸五甲酯酸解反应动力学数据,得到2-膦酸丁烷-1,2,4-三羧酸五甲酯和2-膦酸基丁烷-1,2,4-三羧酸三甲酯酸解反应的表观活化能分别为37.87和42.72 kJ/mol。结果表明,用氯化氢干气酸解2-膦酸丁烷-1,2,4-三羧酸五甲酯制备PBTCA是可行的。     

L-抗坏血酸-2-棕榈酸酯钠的合成工艺研究

以L-抗坏血酸和棕榈酰氯为基本原料，以5，6-D-异亚丙基也-抗坏血酸为中间产物，在无水吡啶中进行酯化反应，经成盐和脱保护反应，制得最终产品。总收率为47％-51％。     

4-溴-2-丁炔酸甲酯的合成

炔丙醇在PPTS催化下由二氢吡喃保护,与溴乙烷格氏试剂反应生成相应的格氏试剂,然后与氯甲酸甲酯反应得到羟基丁炔酸甲酯四氢吡喃醚,在PPTS催化下脱保护后进行甲磺酰化,由溴化钠进行溴取代后合成了4-溴-2-丁炔酸甲酯,总收率达53%。     

Pd(Ⅱ)催化1,4-二苯基-1,3-丁二炔的合成

以苯乙炔为原料制备1,4-二苯基-1,3-丁二炔。以钯催化自偶联的方法合成对称性芳基丁二炔,通过优化碱、溶剂、反应时间和温度等条件得出最优反应条件。结果表明,采用最优条件,在2 mmol Ag NO3促进作用下,1,4-二苯基-1,3-丁二炔的产率达84.3%。     

Z-2-碘-2-丁烯甲烷酸酯的新合成方法

设计了一种合成标题化合物的新方法,以Z-2-碘-2-丁烯醛为起始原料,通过碘代、还原和酯化合成出了目标产物,总收率81.1%.产品的结构经1HNMR、高分辨质谱确证.     

末端炔烃二聚反应的研究进展

末端炔烃二聚反应是一类构建碳碳键的重要反应,其相应的产物-共轭二炔广泛存在于天然产物、药物、有机合成、材料化学等领域。介绍了近年来末端炔烃二聚生成对称和不对称共轭二炔以及相关机理的研究进展,指出在发展新颖的催化体系的同时,也要不断加深末端炔烃二聚反应的绿色化研究。     

Copper‐Catalyzed Highly Efficient Multicomponent Reactions of Terminal Alkynes,Acid Chlorides,and Carbodiimides: Synthesis of Functionalized Propiolamidine Derivatives

Functionalized propiolamidine derivatives were prepared in good to excellent yields under very mild conditions via a copper‐catalyzed multicomponent reaction (MCR) of readily available terminal alkynes, acid chlorides and carbodiimides with the assistance of triethylamine. The mechanism of this MCR is postulated.     

Highly Efficient Pd/Tetraphosphine Catalytic System for Copper-Free Sonogashira Reactions of Aryl Bromides with Terminal Alkynes

Abstract  

In this study, an easily synthesized polydentate ligand N,N,N’,N’-tetra(diphenylphosphinomethyl)-1,2-ethylenediamine (1) in combination with [Pd(C₃H₅)Cl]₂ was found to be an active catalyst in copper-free Sonogashira reactions. Most substrates, including steric hindered phenyl bromides and heteroaryl bromides, could couple efficiently with terminal alkynes in the presence of low catalyst loading (0.1 mol%) and this catalytic system showed excellent functional group tolerance. The influence of water in this system was also preliminarily investigated via ³¹P NMR in situ; that is, appropriate water favors the reaction while excess hindered this reaction.     

Reactions of Alkynes Using Heterogeneous and Homogeneous Cationic Gold Catalysts

The use of both heterogeneous and homogeneous gold catalysts for the reactions of alkynes is described. The reaction of ethyne with hydrogen chloride to make vinyl chloride monomer is initially described using gold supported on activated carbon. This reaction involves Au³⁺ as the reactive species and it is now known that higher alkynes can also be hydrochlorinated with the products of Markovnikov addition being formed. Subsequently, there is now a rich chemistry involving cationic gold or gold complexes as homogeneous catalysts for a very broad range of reactions involving alkynes, and some examples are discussed, including the nucleophilic addition of amines and alcohols to alkynes. Given the range of reactions that gold catalyses as a homogeneous catalysts this may be indicative that many more heterogeneously catalysed reactions using gold can be expected to be discovered.     

Synthesis of Isoquinoline Derivatives through Rhodium(III)‐ Catalyzed Reactions of Benzylamines with Non‐Terminal Alkynes

A new rhodium(III)‐catalyzed N‐annulation reaction of benzylamines with internal alkynes has been developed. Observations made during these efforts suggest that the mechanistic pathway followed in this process involves direct participation of benzylamines without their preliminary oxidative dehydrogenation. Moreover, N‐annulation reactions of primary benzylamines result in the formation of mixtures of isoquinolines and 8‐vinylisoquinolines. Finally, secondary and tertiary benzylamines undergo rhodium(III)‐catalyzed N‐annulation reactions to generate the respective isoquinolinium and hydroisoquinolinium salt products.

     

Gold-Catalyzed Cascade Reactions of Alkynes for Construction of Polycyclic Compounds

The development of cascade reactions is an area of considerable interest in modern organic chemistry. Efficient cascade reactions realize the economical synthesis of complex target molecules through multiple bond formations in a single operation. Elementary reactions that form fewer waste products are desirable in terms of atom economy and in order to suppress side product formation in sequential processes. Recent advances in homogeneous gold catalysis have opened up further possibilities for cascade reactions. In this review, recent advances in gold-catalyzed cascade cyclizations of alkynes are summarized. In particular, cascade reactions based on nucleophilic/electrophilic addition, carbene cyclopropanation/insertion, ring expansion, and cycloaddition are highlighted. Notably, many of the cascade reactions shown in this mini-review feature no theoretical waste products.     

Room Temperature Lewis Base‐Catalyzed Alumination of Terminal Alkynes

An efficient and mild access to mixed dimethylalkynylaluminum reagents has been developed via a direct Lewis base‐catalyzed alumination of terminal alkynes by trimethylaluminum. The use of bis(trimethylsilyl)methylamine enables the metalation at room temperature with only 1% of catalyst loading.     

Preparation of Benzothiophenes and Benzoselenophenes from Arylamines and Alkynes via Radical Cascade Reactions

An intermolecular radical cascade reaction between readily prepared o‐methylthio‐arylamines or o‐methylselanyl‐arylamines and alkynes for the preparation of valuable benzothiophenes or benzoselenophenes is reported. These transformations occur efficiently with complete regioselectivity and the products are obtained in moderate to good yields. The current protocol is successfully applied to the synthesis of the key intermediates of the drug raloxifene and an AT₁ receptor antagonist.

     

Copper‐Catalyzed Selective Semihydrogenation of Terminal Alkynes with Hypophosphorous Acid

A novel copper‐catalyzed selective semihydrogenation of terminal alkynes using hypophosphorous acid as hydrogen donor took place efficiently to afford the corresponding alkenes in high yields. A broad range of substituted terminal aromatic and aliphatic alkenes, including terminal dienes and enynes bearing internal triple bonds, can be efficiently synthesized by this reaction.