Electrophilic Cyclization of 2-Chalcogenealkynylanisoles: Versatile Access to 2-Chalcogen-benzo[b]furans
摘要:
An efficient synthesis of 2-chalcogen-3-substituted-benzo[b]furan compounds has been accomplished via electrophilic cyclization reaction of 2-chalcogenealkynyl anisoles using I-2, ICl, Br-2 and PhSeBr as electrophile sources. The product distributions were strongly dependent on the nature of substituents in the aromatic ring of anisole and on the chalcogen atom directly bonded to the triple bond. The 2-chalcogen-3-iodo-benzo[b]furans obtained smoothly underwent conversion to more complex structures of benzo[b]furan derivatives via palladium- or copper-catalyzed cross-coupling reaction with thiols, diphenyl diselenides, and zincates.
Electrophilic Cyclization of 2-Chalcogenealkynylanisoles: Versatile Access to 2-Chalcogen-benzo[b]furans
摘要:
An efficient synthesis of 2-chalcogen-3-substituted-benzo[b]furan compounds has been accomplished via electrophilic cyclization reaction of 2-chalcogenealkynyl anisoles using I-2, ICl, Br-2 and PhSeBr as electrophile sources. The product distributions were strongly dependent on the nature of substituents in the aromatic ring of anisole and on the chalcogen atom directly bonded to the triple bond. The 2-chalcogen-3-iodo-benzo[b]furans obtained smoothly underwent conversion to more complex structures of benzo[b]furan derivatives via palladium- or copper-catalyzed cross-coupling reaction with thiols, diphenyl diselenides, and zincates.
Synthesis of 2,3-bis-organochalcogenyl-benzo[<i>b</i>]chalcogenophenes promoted by Oxone®
作者:Gelson Perin、Liane K. Soares、Paola S. Hellwig、Marcio S. Silva、José S. S. Neto、Juliano A. Roehrs、Thiago Barcellos、Eder J. Lenardão
DOI:10.1039/c9nj00526a
日期:——
We report here an alternative and tunable metal-free synthesis of benzo[b]chalcogenophenes via the electrophilic cyclization of 2-functionalized chalcogenoalkynes promoted by Oxone®. The use of mild reaction conditions, efficiency and generality are characteristics of this new approach, which was suitable to convert different diselenides and 2-functionalized chalcogenoalkynes into a total of twenty-two
我们在这里报告苯并[的替代和可调不含金属的合成b ] chalcogenophenes经由通过提升的冰冷的2-官能chalcogenoalkynes亲电环化反应。该新方法的特点是使用温和的反应条件,效率和通用性,适用于将不同的二硒化物和2-官能化硫属炔烃转化为总共22种2,3,3-双-有机och基-苯并[ b ]硫属oph烯,其中十八个是第一次合成。在Pd催化的与苯乙炔的反应中,将新型化合物2-(丁基硒基)-3-(苯基硒基)苯并呋喃用作底物,以高收率获得Sonogashira的偶联衍生物。
Synthesis of alkynyltellurides mediated by K<sub>3</sub>PO<sub>4</sub> and DMSO
作者:Manoela do Sacramento、Larissa Menezes、Bruna Goldani、Gelson Perin、Marcio S. Silva、Thiago Barcellos、Diego Alves
DOI:10.1039/c9nj01995b
日期:——
In the present work, a simple method for the synthesis of alkynyltellurides is described by the reactions of terminal alkynes with diorganyl ditellurides in the presence of a catalytic amount of K3PO4. In both substrates, it was possible to vary the aryl and alkyl groups, obtaining the products of interest in short reaction times and in yields ranging from 30 to 93%. This methodology, different from
在目前的工作中,描述了一种简单的合成炔基碲化物的方法,该方法是在催化量的K 3 PO 4存在下,末端炔烃与二有机基二碲化物反应。在两种底物中,都可以改变芳基和烷基,从而以较短的反应时间和30%至93%的产率获得目标产物。该方法与文献中已经报道的方法不同,具有使用催化量的弱碱而不使用金属催化剂的优点。
Magnetite (Fe3O4) nanoparticles: an efficient and recoverable catalyst for the synthesis of alkynyl chalcogenides (selenides and tellurides) from terminal acetylenes and diorganyl dichalcogenides
作者:Marcelo Godoi、Daiane G. Liz、Eduardo W. Ricardo、Manuela S.T. Rocha、Juliano B. Azeredo、Antonio L. Braga
DOI:10.1016/j.tet.2013.09.095
日期:2014.5
We present herein a new and efficient methodology for the synthesis of alkynyl chalcogenides from terminal acetylenes and diorganyl dichalcogenides, catalyzed by Fe3O4 nanoparticles. This new approach provided the desired products in good to excellent yields. Moreover, the catalyst was easily recoverable using an external magnet and reused for further experiments without loss of catalytic activity. (C) 2013 Elsevier Ltd. All rights reserved.