末端炔烃二聚反应合成共轭烯炔的研究进展

综述了不同催化体系催化末端炔烃二聚反应合成共轭烯炔化合物的研究进展. 其中催化体系主要包括过渡金属配合物、镧系和锕系金属配合物、第三主族元素配合物以及有机催化剂. 实验结果表明: 不同催化体系对末端炔烃二聚反应的选择性控制有影响, 尤其是区域选择性(头-头二聚或头-尾二聚).     

联吡啶配体促进铬催化炔烃的顺式硼氢化反应（英文）

报道了金属铬催化炔烃的硼氢化反应.廉价易得的三氯化铬在4,4’-二叔丁基-2,2’-联吡啶配体及单质镁的还原作用下表现出高反应活性,催化实现了频哪醇硼烷与炔烃加成的硼氢化反应,为室温条件下制备烯基硼化合物提供了一条有效的合成策略.     

膦酰保护基促进选择性Hay偶联制备非对称1,3-二炔（英文）

报道了芳香末端炔烃与单膦酰基-保护二炔的选择性Hay偶联反应. Ph_2P(O)的极性使得产物非对称1,3-二炔易与副产物分离.单膦酰基-保护二炔的低反应活性减少了自身氧化偶联,从而提高了目标产物的产率.很多芳香末端炔烃与单膦酰基-保护二炔都能应用于本Hay偶联反应,且相应非对称1,3-二炔产物的产率为中等到好.产物非对称1,3-二炔能用于合成非对称炔-二炔烃及环多炔烃.     

深共融溶剂中合成2,4-二取代喹啉衍生物

在氯化胆碱和氯化锌组成的深共融溶剂中,以2-氨基苯乙酮和芳香炔烃为原料,通过环化偶联反应,合成了一系列2,4-二取代喹啉衍生物;当n(氯化胆碱)∶n(氯化锌)=1∶2,反应温度为80℃时,反应3 h即获得高达98%的产率.该方法无需额外添加催化剂,而且反应条件温和、操作简单、底物范围较广泛.     

氯磷酸二苯酯介入的芳香醛与砜缩合制备非对称芳香炔烃

氯磷酸二苯酯促进芳香醛与砜缩合反应在室温下有效进行,能高收率形成对应的非对称芳香炔烃.考察了醛及砜芳环上取代基对反应的影响,结果表明不论是吸电子基还是给电子基对反应都无明显影响,制备了一系列官能团化的非对称二苯基炔烃、噻吩及吡啶类炔烃、香豆素类炔烃及二苯基膦酰基保护的二炔烃和三炔烃,并从分子结构上阐明了本缩合反应可在室温下有效进行的原理.     

α-二羰基结构的构建及应用

β-二羰基化合物是有机合成的重要中间体,其化学性质也是有机化学教学中的重点。本文在此基础上介绍了同样具有二羰基结构的α-二酮类化合物的合成方法和相关应用。本文所述内容涉及炔烃的水合反应、炔烃的氧化反应、光催化反应等,既与有机化学教学内容紧密相关又有所延伸。此外,本文所介绍的α-二羰基化合物的应用能拓展学生知识面,提高学生学习兴趣。     

一种合成3,5-二取代异噁唑的新方法

研究了端基炔烃和醛肟在间氯过氧苯甲酸和催化量碘苯作用下的[3+2]环合反应, 结果表明, 该过程经过一个有机高价碘中间体而进行. 通过该反应, 端基炔烃在氧化剂间氯过氧苯甲酸和催化剂碘苯的作用下与醛肟反应, 常温下可得到产率良好并具有区域选择性的3,5-二取代异噁唑化合物. 本文考察了反应条件的影响, 提出了可能的反应机理, 为简便快速合成3,5-二取代异噁唑化合物提供了一种新方法.     

铜催化合成2-亚氨基-1,2-二氢喹啉化合物(英文)

报道了室温条件下磺酰叠氮、2-氨基苯甲醛、末端炔烃通过一价铜催化合成2-亚氨基-1,2-二氢喹啉化合物的方法.该反应条件温和,具有较好的底物普适性,当更改底物炔烃的类型时,可以选择控制不同产物的合成,包括二氢喹啉和N-磺酰脒类化合物.     

超临界二氧化碳中羰基钴催化的端基炔烃环三聚反应研究

原子经济性良好的炔烃[2+2+2]环加成反应与绿色溶剂超临界二氧化碳相结合,是一个符合绿色化学原则的环境友好反应过程.建立了一个纯超临界二氧化碳介质中八羰基二钴催化的端基炔烃环三聚反应体系,在优化的反应条件下,以较高产率选择性地制备1,2,4-三取代苯衍生物.优化了催化剂用量、二氧化碳压力、反应温度及时间等反应条件,讨论了反应物料及催化剂在超临界二氧化碳介质中的溶解性和相行为,提出了端基炔烃环三聚反应机理,并将反应底物从C≡C键拓展至C≡N键,对超临界二氧化碳介质中炔-腈环加成反应进行了初步探索.优化出的炔烃环三聚催化反应体系无需使用有机助溶剂和各类助剂,底物适应性好,产物选择性高,为合成1,2,4-三取代苯衍生物提供了一种绿色合成方法.     

Cp_2ZrCl_2-i-BuMgBr试剂体系的研究——烯烃和炔烃的还原二聚反应和二烯烃的环化

二氯二茂锆同异丁基格氏试剂以1:2摩尔比反应,于室温下生成有机锆中间体,后者同烯烃、炔烃或二烯反应,最后生成还原的二聚物或分子内环化产物。     

1,3-Diyne chemistry: synthesis and derivations

Conjugated diynes have attracted more and more attention not only for their unique rod like structures and wide existence in nature product, but also the abundant properties and derivations of them. Although oxidative dimerization of alkynes or Cadiot–Chodkiewicz reactions were the main pathway and have achieved great success in the synthesis of diynes, oxidative cross coupling, FBW rearrangement as well as diyne metathesis emerged rapidly recently. Moreover, diynes could be precursors of basic heterocycles, which represented an emerging research area. This Letter will cover the recent progresses in the synthesis and further derivations of diynes.     

Rhodium(I)-catalyzed [2 + 2 + 2] cycloadditions of ynamides in the synthesis of amide-substituted chiral biaryls

Rhodium(I)-catalyzed [2 + 2 + 2] cycloadditions of sterically encumbered aryl-substituted ynamides with various diynes are described here. These cycloadditions provide the synthesis of an array of new chiral amide-substituted biaryls that can be useful in future chiral ligand designs.     

New route synthesis of indolizines via 1,3-dipolar cycloaddition of pyridiniums and alkynes

A convenient synthesis of 2,3-di and 1,2,3-trisubstituted indolizines has been achieved via a 1,3-dipolar cycloaddition of pyridiniums and alkynes. Various alkynes and diynes were used instead of dimethyl acetylenedicarboxylate (DMAD) and its analogues in the traditional method. The corresponding 1,2,3-trisubstituted indolizines are useful building blocks for the construction of complex indolizine derivatives.     

过渡金属催化下二醋酸碘苯-四正丁基溴化铵与苯乙烯衍生物选择性加成反应的研究

在过渡金属催化下,二醋酸碘苯-四正丁基溴化铵体系与烯烃发生加成反应,从而可同时引入溴及含氧官能团.该反应具有很高的区域与顺反选择性.因此,作为一种高选择性的双官能化策略,它将在有机合成中有着较好的应用价值.     

Radical cyclization in heterocycle synthesis. 12. Sulfanyl radical addition-addition-cyclization (SRAAC) of unbranched diynes and its application to the synthesis of A-ring fragment of 1alpha,25-dihydroxyvitamin D3

Sulfanyl radical addition-addition-cyclization (SRAAC) of unbranched diynes proceeded smoothly to give cyclized exo-olefins, while the sulfanyl radical addition-cyclization-addition (SRACA) of diynes having a quaternary carbon gave cyclized endo-olefins. This method was successfully applied to the synthesis of A-ring fragment of 1alpha,25-dihydroxyvitamin D3.     

Ruthenium-catalyzed transfer oxygenative cyclization of α,ω-diynes: unprecedented [2 + 2 + 1] route to bicyclic furans via ruthenacyclopentatriene

A novel oxygen-atom-transfer process enables the catalytic [2 + 2 + 1] synthesis of bicyclic furans from α,ω-diynes with DMSO. [CpRu(AN)(3)]PF(6) catalyzed the transfer oxygenative cyclization of diynes with aryl terminal groups, while those of diynes with alkyl terminal groups were effectively promoted by the corresponding Cp* complex. A mechanism for bicyclic furan formation via a ruthenacyclopentatriene was proposed on the basis of both experimental and theoretical studies.     

An efficient route to highly functionalized benzene derivatives by rhodium-catalyzed dimerization of diynes

An intermolecular efficient dimerization of diynes via Rh-catalyzed cycloaddition is presented. This protocol allows for the expedient synthesis of structurally diverse benzene derivatives, which retain an alkyne unit for post-functionalization to realize molecules with potential medicinal value and extended molecular complexity. The transformation is carried out in toluene and employs Rh(COD)₂OTf₃ as the metal source. Diversely decorated diynes tethered by nitrogen atom and ester were compatible with these conditions and furnished substituted benzenes with excellent selectivity.     

Synthesis of Spirocyclic C‐Arylglycosides and ‐Ribosides by Ruthenium‐Catalyzed Cycloaddition

Spirocyclic C‐arylglycosides were synthesized from the appropriately protected δ‐gluconolactones. Addition of lithium acetylide followed by glycosylation with 3‐(trimethylsilyl)propargyl alcohol converted the δ‐gluconolactones into silylated diynes. After desilylation, subsequent ruthenium‐catalyzed cycloaddition of the resultant diynes with alkynes or chloroacetonitrile gave spirocyclic C‐arylglycosides in good yields and selectivity. This strategy was also extended to the synthesis of spirocyclic C‐arylribosides from the known γ‐ribonolactone derivative. Moreover, silver‐catalyzed iodination of the sugar diynes followed by ruthenium‐catalyzed cycloaddition with acetylene delivered spirocyclic C‐iodophenylglycosides and ‐ribosides, which were subjected to palladium‐catalyzed C? C bond‐forming reactions and copper‐catalyzed coupling with nitrogen heterocycles to lead to various derivatives.     

New method based on 1-(trimethysilyl)alk-1-yne to prepare 1,4-skipped diynes

[reaction: see text] We have developed a novel reaction between a terminal TMS-alkyne and a propargyl halide in the presence of a fluoride source and a catalytic amount of copper iodide to prepare 1,4-skipped diynes with good yields and in mild conditions. We have shown that this reaction also works very well with germanium and tin derivatives as an alternative to silicon. This new method can be useful for the synthesis of polyunsaturated fatty acids.     

Zirconocene-mediated, high-yielding macrocyclizations of silyl-terminated diynes

A series of silyl-terminated diynes of varying lengths and substitution patterns have been prepared. These diynes undergo zirconocene coupling with selective formation of trimeric macrocycles from linear alkynes, while nonlinear diynes give cyclodimeric products. The length of the linear diynes can be increased for the preparation of macrocycles with large nanoscale cavities. Reaction of the zirconium-containing macrocycles with acid results in the synthesis of metal-free cyclophanes. All of these macrocycles were prepared in multigram quantities, in the absence of high-dilution conditions, to give products in > 75% yield that are easily purified as crystalline solids.