Three-Component Coupling Synthesis of Diversely Substituted N-Aryl Pyrroles Catalyzed by Iron(III) Chloride

An efficient and operationally simple three-component coupling synthesis of varieties of N-aryl substituted pyrroles is described in the presence of sustainable and environmentally benign metal catalyst, FeCl₃. This method provides a straightforward approach for the synthesis of N-aryl substituted pyrroles in good yields from easily accessible starting materials such as nitroalkenes, 1,3-dicarbonyl compounds, and primary aromatic amines. The reaction proceeds through a catalytic sequence of Fe(III)-catalyzed amination/Michael/cycloisomerization reactions.

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An Optimized Ni-catalyzed Chan-Lam Type Coupling: Enantioretentive Access to Chiral N-Aryl Sulfinamides

C−N bond formation takes on a critical significance in reactions of organic synthesis, material production and pharmaceutical manufactory. Chan-Lam has proposed a useful methodology to furnish secondary arylamides under mild conditions. However, when chiral sulfinamides serve as the coupling precursors, the Cu-catalyzed coupling reaction is found with low efficacy. Complex side-products are generated under classic conditions. Moreover, it led to the racemization of the coupling product. In this study, an optimized Ni-catalyzed Chan-Lam type coupling conditions were proposed, which resulted in clean conversion from chiral sulfinamides and arylboronic acids to offer N-aryl sulfinamides efficiently and enantioretentively. The trans-N¹,N²-dimethylcyclohexane-1,2-diamine was proven as the most efficient ligand. Under the optimized conditions, a series of chiral N-aryl sulfinamides was prepared with high chemical yield without racemization. Furthermore, a plausible and novel mechanism was proposed. Interestingly, the method could efficiently furnish a wide variety of C−X bonds by coupling arylboronic acids with different nucleophiles.     

微波辐射下N-芳基甲酰胺的合成

以甲酸作为甲酰化试剂，通过微波辐射合成的11种N-芳基甲酰胺。产率比传统 方法有所提高，反应时间缩短了20-120倍。     

噻吩N-芳基吡唑类化合物的合成及光活化活性研究

以2,6-二氯-4-三氟甲基苯胺和溴代噻吩等为起始原料,设计并合成了12个未见报道的噻吩芳基吡唑类化合物5a～51,经1H NMR,13C NMR,ESI-MS和元素分析对化合物的结构进行了表征.初步生物活性测定结果表明,目标化合物均具有一定的光活化杀虫活性,其中51表现最为明显.在光照下对白纹伊蚊幼虫的LC50值为0.04 μg/mL,达到了商品化品种氟虫腈的水平.     

A Facile Synthesis of N-Aryl Substituted Piperidones

A general and efficient procedure for the synthesis of N‐aryl‐substituted 4‐piperidones was developed. The two step syntheses proceeded with an overall yield of 60%‐83% using L‐proline as the ligand for the Cu(I)‐catalyzed Ullmann amination followed by subsequent hydrolysis of resulting ketals.     

Direct Waste-Free Synthesis of Amides from Nonactivated Carboxylic Acids and Amines: Application to the Synthesis of Tetrahydroisoquinolines

An efficient, waste-free protocol has been developed for the synthesis of amides directly from nonactivated carboxylic acids and amines without any tedious purification. Fatty acids were also converted into corresponding amides by reaction with nonactivated amines. The synthesized amides were cyclized to tetrahydroisoquinolines in good yields.     

Consecutive Ring Expansion and Contraction for the Synthesis of 1‐Aryl Tetrahydroisoquinolines and Tetrahydrobenzazepines from Readily Available Heterocyclic Precursors

Tetrahydroisoquinolines and tetrahydrobenzazepines were prepared by acid‐promoted ring contraction of cyclic ureas, which were themselves formed by ring expansion of indolines and tetrahydroquinolines. The consequent overall one‐carbon insertion reaction gives these 6‐ and 7‐membered heterocyclic scaffolds in three steps from readily available precursors. Other ring sizes may be formed by an alternative elimination reaction of bicyclic structures. Scalability of the method was demonstrated by operating it in a flow system.     

Ruthenium(II)/Chiral Brønsted Acid Co‐Catalyzed Enantioselective Four‐Component Reaction/Cascade Aza‐Michael Addition for Efficient Construction of 1,3,4‐Tetrasubstituted Tetrahydroisoquinolines

An elegant synergistic catalytic system comprising a ruthenium complex with a chiral Brønsted acid was developed for a four‐component Mannich/cascade aza‐Michael reaction. The ruthenium‐associated ammonium ylides successfully trapped with in situ generated imines indicates a stepwise process of proton transfer in the ruthenium‐catalyzed carbenoid N?H insertion reaction. The different decomposition abilities of various ruthenium complexes towards diazo compounds were well explained by the calculated thermodynamic data. The transformation features a mild, rapid, and efficient method for the synthesis of enantiomerically pure 1,3,4‐tetrasubstituted tetrahydroquinolines bearing a quaternary stereogenic carbon center from simple starting precursors in moderate yields with high diastereo‐ and enantioselectivity.     

聚合色素的研究 XI.蒽醌型聚酯色素的合成与可加工性

用熔融缩聚法合成蒽醌型聚酯色素，研究了色素用量、反应温度和反应时间等对反应的影响，对用所合成聚合色素着色的聚酯的可加工性能作了初步的研究。     

Pinacol Coupling Reactions Catalyzed by Active Zinc

The facile carbon-carbon bond formation is a forever goal and indispensable tool in organic synthesis1. Metal-mediated coupling reactions as highly efficient processes are always a major focus of directed synthesis2. Pinacol coupling reactions have been recognized to be efficient and selected alternatives for preparing several kinds of compounds3, not to mention those can be as versatile tools for preparing building blocks or exerted on synthesizing natural products in several key steps4. The …     

可见光驱使铜盐催化芳香烃二氟烷基化反应

以CuI为铜源, 通过原位形成光催化剂的途径, 实现了室温下可见光驱使铜催化溴二氟乙酸乙酯、溴二氟酰胺等对芳烃及杂芳烃的二氟烷基化反应. 该反应条件温和、原料廉价易得、底物适用范围广、产率较高, 为合成二氟烷基(杂)芳烃化合物提供了一种方法. 机理研究表明, 该反应可能经历了单电子转移的自由基反应历程.     

C−C Coupling of Benzyl Fluorides Catalyzed by an Electrophilic Phosphonium Cation

The activation and cleavage of benzyl fluorides by the electrophilic organofluorophosphonium catalyst, [(C₆F₅)₃PF][B(C₆F₅)₄], is reported and used for the preparation of 1,1‐diarylalkanes (37 examples) and substituted aryl homoallylic alkenes (14 examples). This procedure involves mild conditions, avoids harmful waste, and is compatible with a range of substituted arenes and allylic silanes.     

红树植物内生真菌Penicillium sp.中一个醌类化学成分的研究

利用各种层析手段(反相ODS健合硅胶、葡聚糖凝胶LH-20柱层析等),从红树植物内生真菌Penicil-liumsp.的发酵液中分离纯化了1个醌类化合物,通过各种波谱实验(1D-NMR,2D-NMR以及ESIMS)确定其结构为:5-甲氧基-11,12,18,19-四羟基蒽醌(1)。     

聚合手性Salen-V(Ⅴ)配合物催化醛的不对称

以聚合手性salen-V(Ⅴ)为催化剂, 对醛的三甲基硅氰化反应进行了研究, 在 -20 ℃和1.2%催化剂量下, 以苯甲醛为底物获得了91%的ee值和98%的转化率, 对其它几种芳香醛和脂肪醛也取得较好的反应结果. 催化剂可以方便地回收, 重复使用8次仍然保持很好的反应活性和对映体选择性.     

TiO2光催化降解聚乙烯薄膜

TiO2光催化降解聚乙烯薄膜;纳米TiO2;固相光催化;聚乙烯塑料;降解     

Coupling of Thiols Catalyzed by Trinitratocerium(IV) Bromate

Russian Journal of Organic Chemistry -     

CBr4‐Mediated Cross‐Dehydrogenative Coupling Reaction of Amines

A novel CBr₄‐mediated dehydrogenative Povarov/aromatization tandem reaction of glycine derivatives with alkenes, leading to complex quinoline derivatives, and a CBr₄‐mediated dehydrogenative C?H functionalization of N‐aryl tetrahydroisoquinolines with nucleophiles to form C?C and C?P bonds are reported. The reactions were performed under very simple and mild reaction conditions; only CBr₄ was used as a promoter. A plausible mechanism involving a radical process is proposed.