A radical cascade cyclization of 2-alkynylthioanisoles with α-oxocarboxylic acids with AgNO3 has been described. This reaction provides a novel route to directly access 3-acylbenzothiophenes from simple chemical feedstocks. In particular, the utility of the approach was demonstrated by its application to the synthesis of a polymerization inhibitor and a raloxifene precursor.
Synthesis of 3-(Arylsulfonyl)benzothiophenes and Benzoselenophenes via TBHP-Initiated Radical Cyclization of 2-Alkynylthioanisoles or -selenoanisoles with Sulfinic Acids
作者:Jian Xu、Xiaoxia Yu、Jianxiang Yan、Qiuling Song
DOI:10.1021/acs.orglett.7b02971
日期:2017.12.1
tert-Butyl hydroperoxide-initiated radical cyclization of 2-alkynylthioanisoles or -selenoanisoles with sulfinic acids has been developed. This reaction is applicable to a wide substrate scope via one C(sp3)–S(Se) bond cleavage and two C(sp2)–S(Se) bond formation, leading to the synthesis of 3-(arylsulfonyl)benzothiophenes or -benzoselenophenes under mild conditions.
Synthesis of 3-(Methylsulfonyl)benzo[<i>b</i>]thiophenes from Methyl(2-alkynylphenyl)sulfanes and Sodium Metabisulfite via a Radical Relay Strategy
作者:Xinxing Gong、Mengjiao Wang、Shengqing Ye、Jie Wu
DOI:10.1021/acs.orglett.9b00100
日期:2019.2.15
A radical relay strategy for the generation of 3-(methylsulfonyl)benzo[b]thiophenes through a reaction of methyl(2-alkynylphenyl)sulfanes with sodium metabisulfite in the presence of a photocatalyst under visible light irradiation is developed. This photoinduced sulfonylation proceeds efficiently under mild conditions by using a catalytic amount of sodium methylsulfinate as an initiator. During the
开发了一种自由基中继策略,用于在可见光照射下,在光催化剂的存在下,通过甲基(2-炔基苯基)亚砜与偏亚硫酸氢钠的反应生成3-(甲基磺酰基)苯并[ b ]噻吩。通过使用催化量的甲基亚磺酸钠作为引发剂,该光诱导的磺酰化在温和条件下有效地进行。在反应过程中,原位生成的甲基自由基是关键中间体,它与二氧化硫结合进行自由基中继,从而生成含甲基磺酰基的化合物。
Synthesis of Benzo[<i>b</i>]thiophenes via Electrophilic Sulfur Mediated Cyclization of Alkynylthioanisoles
作者:Zahra Alikhani、Alyssa G. Albertson、Christopher A. Walter、Prerna J. Masih、Tanay Kesharwani
DOI:10.1021/acs.joc.1c02606
日期:2022.5.6
A stable dimethyl(thiodimethyl)sulfonium tetrafluoroborate salt was employed for the electrophilic cyclization reaction of o-alkynyl thioanisoles for the synthesis of 2,3-disubstituted benzo[b]thiophenes. The reaction described herein works well with various substituted alkynes in excellent yields, and a valuable thiomethyl group was introduced with ease. The reaction utilizes moderate reaction conditions
一种稳定的二甲基(硫代二甲基)锍四氟硼酸盐用于邻炔基硫代苯甲醚的亲电环化反应,用于合成 2,3-二取代苯并[ b ]噻吩。本文描述的反应以优异的收率与各种取代的炔烃一起工作,并且很容易引入有价值的硫甲基。该反应利用温和的反应条件和环境温度,同时耐受各种功能。为了阐明机理,证明了使用二甲基(硫代二甲基)锍四氟硼酸盐与二苯乙炔的亲电加成反应。
Synthesis of 3‐Thiocyanobenzothiophene via Difunctionalization of Active Alkyne Promoted by Electrochemical‐Oxidation
A clean and efficient electrochemical method for the preparation of 3-thio/selenocyanatobenzothiophenes has been developed. This method features excellent functional group compatibility, broad substrate scope and easy to scale-up in continuous flow.