Benziodoxole Triflate as a Versatile Reagent for Iodo(III)cyclization of Alkynes
作者:Bin Wu、Junliang Wu、Naohiko Yoshikai
DOI:10.1002/asia.201701530
日期:2017.12.14
Hyperactive: A benziodoxole triflate promotes iodo(III)cyclization of alkynes tethered to a variety of nucleophilic moieties, affording benziodoxole-appended (hetero)arenes such as benzofurans, benzothiophenes, isocoumarins, indoles, and polyaromatics. These unprecedented (hetero)aryl-IIII compounds are easy to purify, air- and thermally stable, and amenable to various synthetic transformations.
Catalyst-Free Formal Thioboration to Synthesize Borylated Benzothiophenes and Dihydrothiophenes
作者:Darius J. Faizi、Ashlee J. Davis、Fiach B. Meany、Suzanne A. Blum
DOI:10.1002/anie.201608090
日期:2016.11.7
isolated prior to downstream functionalization. This methodology has been extended to the synthesis of borylated dihydrothiophenes. Mechanistic experiments suggest that the operative mechanistic pathway is through boron‐induced activation of the alkyne followed by electrophilic cyclization, as opposed to S−B σ bond formation, providing a mechanistically distinct pathway to the thioboration of C−C π bonds.
Synthesis of 2,3-Disubstituted Benzo[<i>b</i>]thiophenes via Palladium-Catalyzed Coupling and Electrophilic Cyclization of Terminal Acetylenes
作者:Dawei Yue、Richard C. Larock
DOI:10.1021/jo011016q
日期:2002.3.1
alkyl-substituted terminal acetylenes undergo this coupling and cyclization to produce excellent yields of benzo[b]thiophenes. (Trimethylsilyl)acetylene also undergoes this coupling/cyclization process with I(2), NBS, and the sulfur and selenium electrophiles to afford the corresponding 2-(trimethylsilyl)benzo[b]thiophenes. However, cyclization of the silyl-containing thioanisole using Br(2) affords
The efficient synthesis of morphologically different heteroacenes and the rapid determination of their solid-state and electronic properties are still challenging tasks, which slow down progress in the development of new materials. Here, we report a flexible and efficient synthesis of unprecedented heterotetracenes based on a platinum- and gold-catalyzed cyclization–alkynylation dominoprocess using
A convenient methodology for the synthesis of mono- and di-halogenated benzo[b]thiophenes is described herein, which utilizes copper(II) sulfate pentahydrate and various sodium halides in the presence of substituted 2-alkynylthioanisoles. The proposed method is facile, uses ethanol as a green solvent, and results in uniquely substituted benzo[b]thiophene structures with isolated yields up to 96%. The