Synthesis of Iso-condensed Heteroaromatic Pyrroles and Their Application in the Preparation of Conducting Polymers

Iso-condensed heteroaromatic pyrroles 1 are 10 -electron aromatic compounds. They are of interest from both theoretical and synthetic points of view. They are the cyclic analogues of heteroaromatic ortho-quinodimethanes 2, and can react with dienophiles in a Diels-Alder reaction to give the synthetically useful cycloadducts 3. Many of them are also of potential pharmaceutical importance because they are isosteric with indoles. Iso-condensed heteroaromatic pyrroles 1 can be used also as the monomers for the synthesis of new conducting polymers 5 with special properties and characteristics. However, the methods for the efficient preparation of the iso-condensed heteroaromatic pyrroles are quite limited. Iso-condensed heteroaromatic pyrroles are generally unstable in acidic conditions and are easily oxidized by air. In our laboratories, we developed three methods for the preparation of this labile heterocyclic ring system under acidic, neutral, and basic conditions.1 Synthesis of the conjugated systems such as 6 for OLED applications will also be discussed.     

三烃基锡杂环羧酸酯的合成

合成了十种三烃基锡杂环羧酸酯R_3~1SnO_2C-R~2(R~1=n-C_4H_9,Ph-CH_2;R~2=呋喃,吡啶,吲哚烷基),利用IR,~1H NMR及元素分析确定了这些化合物的组成和结构。     

Syntheses of Iso-Condensed Heteroaromatic Pyrroles and the Application to the Total Synthese of Natural Products

A novel method, namely the intramolecular 1,3-dipolar cycloaddition and cycloreversion ofazido-alkylidene malonates, for the preparation of iso-condensed heteroaromatic pyrroles has beendeveloped. The application of this method for the synthesis of 2,4-dihydropyrrolo[3,4-b]indole ringsystem, as well as the application of this ring system for the total syntheses of ellipticine alkaloids arereported.     

二丁基锡氮杂环羧酸酯的合成

合成了１０种二丁基锡氮杂环羧酸酯（ｎ－Ｃ４Ｈ９）２Ｓｎ（Ｃｌ）２－ｎ（Ｏ２ＣＲ）ｎ（ｎ＝１,２;Ｒ＝吡啶基,吲哚烷基）,利用元素分析,ＩＲ及＾Ｈ ＮＭＲ表征了它们的结构。     

Synthesis and Characterization of Novel Ferrocenyl-Substituted Pyrroles

The syntheses of new ferrocene substituted pyrroles has been carried out by the reaction of TosMIC with an α, β-unsaturated ferrocene derivative.     

Simple Synthesis of Pyrroles Under Solvent-Free Conditions

Paal–Knorr condensation of 2,5-hexadione with primary amines in the presence of a catalytic amount of praseodymium(III) trifluoromethanesulfonate under solvent-free conditions has been accomplished with an excellent yield. This method is a very easy, rapid, and high-yielding reaction for the synthesis of N-substituted pyrrole derivatives.     

异喹啉稠环吡咯化合物的合成研究进展

概述了异喹啉稠环吡咯化合物的合成方法,主要包括Tschitschibabin反应,Munchnone衍生物的1,3－偶极环加成反应,1,5－电环化反应和硝酮化合物的1,3－偶极环加成反应,参考文献20篇。     

Synthesis and Bioactivity of Novel Fluorinated Heteroaromatic Ureas

In order to find new urea cytokinins, a series of novel fluorinated heteroaromatic ureas have been designed and synthesized. The crystal structure of 3g was further determined by single crystal X-ray diffraction to obtain the structural feature of this class of urea compounds. The preliminary bioassay showed that some title compounds have good cytokinin activity.     

Microwave-Assisted Method for Synthesis of 1,3-Disubstituted Pyrroles

1,3-Disubstituted pyrroles were prepared by a microwave-assisted reaction of pyrrolidine and aldehydes in toluene as well as in solvent-free conditions. Reactions were completed in a few minutes in the solvent-free condition but a long time (up to 30 min) was necessary to complete reactions in toluene. Yields of products depended considerably on the aldehyde used.     

含芳杂环的超支化聚合物的合成与性能研究

在紫外光照射的条件下,以CpCo(CO)2为催化剂,通过3,5-双-(4-炔苯基)-4-苯基-1,2,4-三唑和2,5-双-(4-炔苯基)-1,3,4-(噁)二唑的双炔分别与1-辛炔的[2 2 2]环三聚反应,合成了一类含芳杂环的可溶于普通有机溶剂的新型超支化聚合物.采用红外光谱、核磁共振谱、热失重分析、紫外吸收光谱、荧光光谱、循环伏安法等方法对聚合物进行结构表征和性能测试.结果表明,聚合物具有优异的热稳定性,尤其是含三唑的聚合物热失重5%的分解温度在450℃以上;在800℃时,残余碳化率高达75%.在光激发的条件下,这类聚合物在二氯甲烷溶液中发射深蓝光,其荧光量子效率可达80%.电化学测试结果表明,这类含芳杂环聚合物具有较好的电子传输能力.     

Synthesis of Polyfunctionalized Pyrroles via Green Chemical Methods

Water was found to be an excellent solvent for the one‐pot synthesis of tetrasubstituted pyrrole derivatives under ultrasound involving the standard Knoevenagel condensation followed by the Michael type reaction. A new catalyst free system, excellent atom economy, ultrasound in water medium, short reaction times, good yields (88–93%), and ease of workup make this protocol more attractive and economically viable. The resulting substituted pyrroles are characterized by ¹H and ¹³C NMR, elemental analysis, and mass spectral data.     

A Two Step Synthesis of 1,2,3-Substituted Pyrroles

A method for preparing substituted pyrroles 3a-g in two steps from dihydrofurans 2a-b which were synthesized from α,α-diazocarbonyl derivatives 1a-b was developed. The relevance of this research work lies in the easiness of preparing the substituted dihydrofurans and transforming them into pyrroles under mild conditions.     

Efficient Route for the Synthesis of Highly Substituted Pyrroles

A mild and efficient synthesis of highly substituted pyrroles using the reaction of triphenylphosphine, α-diketone, ammonium acetate, and dialkyl acetylenedicarboxylates is described.     

Tandem Synthesis of Tetrasubstituted NH Pyrroles from Simple Nitriles

An efficient tandem route to obtain tetrasubstituted NH pyrroles in a one-pot manner has been developed, staring from simple nitriles, ethyl bromoacetates, and zinc. This reaction involves oxidative dimerization of the zinc bromide complex of β-enaminoesters using cerium ammonium nitrate (CAN) as an oxidant, affording 2,3,4,5-tetrasubstituted pyrroles in yields up to 91%.     

Recyclable,Graphite-Catalyzed,Four-Component Synthesis of Functionalized Pyrroles

A facile, convenient, and multicomponent coupling strategy for the synthesis of highly functionalized pyrroles is developed using graphite as a catalyst, but devoid of moisture-sensitive metal catalysts and corrosive acidic reagents. This method involves four-component coupling reactions of ethyl acetoacetate compound or diethyl acetylene dicarboxylate, amines, aromatic aldehydes, and nitromethane without an inert atmosphere. This approach provides easy access to highly substituted pyrroles in good yields via one-pot tandem reaction. The method is very simple, straightforward, and environmentally friendly compared to the existing methods.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Synthesis of Novel Heteroaromatic Phthalides as Monomers for Copolyarylenephthalides

Russian Journal of Organic Chemistry - Di- and trimeric symmetric and asymmetric heteroaromatic phthalides containing diphenyl oxide, diphenyl sulfide fragments were synthesized for the first time...     

Synthesis of N-Substituted Pyrroles Under Catalyst- and Solvent-Free Conditions

N-Substituted pyrroles were synthesized under neat conditions by the reaction of aromatic amines with 2, 5-dimethoxytetrahydrofuran in excellent yields.     

生物质木质素磺酸催化合成N-取代吡咯

木质素磺酸是非均相、环境友好的生物质催化剂。本文以造纸废料木质素磺酸钠为原料,通过离子交换的方法制备了木质素磺酸。通过红外、元素分析、滴定等方法表征了木质素磺酸的结构。以木质素磺酸为催化剂,2,5-己二酮与伯胺发生Paal-Knorr反应以较优的产率合成了N-取代吡咯。伯胺的亲核能力越强,反应越容易进行,是典型的亲核反应。