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.
Ni-catalyzed non-activated C–S bond cleavage at ambient temperature for the synthesis of sulfur-containing polycyclic compounds
作者:Takanori Shibata、Ayato Sekine、Mika Akino、Mamoru Ito
DOI:10.1039/d1cc03226g
日期:——
tetracyclic compounds at ambient temperature. The transformation was initiated by non-activated sp2 C–S bond cleavage along with consecutive alkyne insertions. A double intramolecular reaction of a tetrayne and an intermolecular reaction of monoynes were also available, and the corresponding polycyclic compounds were obtained. Moreover, the obtained cycloadduct showed photo-catalytic activity in benzylic
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 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.
Cascade Radical Annulation of 2-Alkynylthio(seleno)anisoles with Acetone or Acetonitrile: Synthesis of 3-Acetomethyl- or Cyanomethyl-Substituted Benzothio(seleno)phenes
for the direct preparation of 3-aceto(cyano)methyl-substituted benzothio(seleno)phenes has been achieved throughC(sp3)–H bondactivation of easily available acetone or acetonitrile and cascade radical cyclization reaction. In this cascade radical cyclization reaction, C(sp2)–C(sp3) and C(sp2)–S bonds, as well as benzenethio(seleno)phene skeletons, can be built along with the cleavage of the C(sp3)–S