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.
A new method for the directsynthesis of 3-phosphinoylbenzothio(seleno)phenes has been achieved through an Ag-mediated radical addition–cyclization of 2-alkynylthio(seleno)anisoles with secondary phosphine oxides in good yields under mild conditions. In this single reaction, benzenethiophene or benzeneselenophene skeleton, C(sp2)–P and C(sp2)–S bonds can be constructed with the cleavage of the C(sp3)–S
Synthesis of 2‐Substituted Benzothio(seleno)phenes and Indoles
<i>via</i>
Ag‐Catalyzed Cyclization/Demethylation of 2‐Alkynylthio(seleno)anisoles and 2‐Alkynyldimethylanilines
Herein, we have successfully developed an efficient protocol for the construction of benzothio(seleno)phenes and indoles through an Ag‐mediated cyclization/demethylation process. Various 2‐substituted benzothio(seleno)phenes and indoles were obtained in good to excellent yields under mild reaction conditions with low catalyst loading. A conceivable reaction mechanism was proposed and supported by an
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.
Cu-Catalyzed Three-Component Coupling of Aryne, Alkyne, and Benzenesulfonothioate: Modular Synthesis of <i>o</i>-Alkynyl Arylsulfides
作者:Xianglong Peng、Chen Ma、Chen-Ho Tung、Zhenghu Xu
DOI:10.1021/acs.orglett.6b02027
日期:2016.9.2
copper-catalyzed three-component coupling reaction of in situ formed arynes, terminal alkynes, and benzenesulfonothioates is described. This reaction provides an efficient modular synthesis of o-alkynyl arylsulfides from easily available starting materials. This process involves one C–S bond and one C–C bond formation in one pot.