Palladium/carboxylic acid-catalyzed alkenylation of heteroarenes and electron-deficient arenes using alkynes underwent C(sp2)–H bond activation in arene substrates to give the corresponding alkenylarenes straightforwardly. The versatility of this transformation is demonstrated by the double alkenylation of functionalized thiophenes and 5,6-difluorobenzothiadiazole with alkynes and provides a one-step access
A Brönsted acid-promoted trifluoromethylselenolation of benzofurans was disclosed by using Se-(trifluoromethyl) 4-methylbenzenesulfonoselenoate as a stable and easily prepared electrophilic trifluoromethylselenolating reagent. A wide range of SeCF3-substituted benzofuran derivatives were obtained in moderate to good yields with excellent regioselectivity. The tandem cyclization/trifluoromethylselenolation
PdCl<sub>2</sub>-Promoted Electrophilic Annulation of 2-Alkynylphenol Derivatives with Disulfides or Diselenides in the Presence of Iodine
作者:Hui-Ai Du、Xing-Guo Zhang、Ri-Yuan Tang、Jin-Heng Li
DOI:10.1021/jo9016309
日期:2009.10.16
of 3-chalcogen-benzo[b]furans via palladium-promoted annulation reactions of 2-alkynylphenol derivatives with disulfides or diselenides and iodide has been developed. In the presence of I2 and PdCl2, both 3-sulfenylbenzofurans and 3-selenenylbenzofurans were selectively prepared from the cyclization of 2-alkynyanisoles with disulfides or diselenides in moderate to excellent yields.
通过2-炔基苯酚衍生物与二硫化物或二硒化物和碘化物的钯促进的环化反应,已开发出有效合成3-硫属元素-苯并[ b ]呋喃的方法。在I 2和PdCl 2的存在下,由2-炔基吲哚与二硫化物或二硒化物的环化反应选择性地制备了3-亚磺酰基苯并呋喃和3-硒烯苯并呋喃,且产率中等至优异。
Synthesis of
<scp>3‐Methylthio</scp>
‐benzo[
<i>b</i>
]furans/Thiophenes
<i>via</i>
Intramolecular Cyclization of
<scp>2‐Alkynylanisoles</scp>
/Sulfides Mediated by
<scp>DMSO</scp>
/
<scp>DMSO</scp>
‐
<i>d</i>
<sub>6</sub>
and
<scp>
SOCl
<sub>2</sub>
</scp>
作者:Beibei Zhang、Xiaoxian Li、Xuemin Li、Fengxia Sun、Yunfei Du
DOI:10.1002/cjoc.202000566
日期:2021.4
with SOCl2 and DMSO was conducted to conveniently furnish the biologically interesting 3‐(methylthio)‐benzo[b]furans/thiophenes via intramolecularcyclization. DMSO acts as a solvent as well as a sulfur source and can also be replaced with DMSO‐d6, enabling the incorporation of the SCD3 moiety of DMSO‐d6 to the 3‐position of the heterocyclic frameworks.
进行2-炔基苯甲醚/硫化物与SOCl 2和DMSO的反应以通过分子内环化方便地提供生物学上令人感兴趣的3-(甲硫基)-苯并[ b ]呋喃/噻吩。DMSO充当溶剂,以及作为硫源,也可以用替换DMSO- d 6,使SCD的掺入3 DMSO-的部分d 6到杂环框架的3位上。
Electrophilic Selenocyanogen Cyclization of Alkynes; Synthesis of Benzofurylselenocyanates, Benzothienylselenocyanates and Indolylselenocyanates
A method to synthesize benzofurylselenocyanates, benzothienylselenocyanates and indolylselenocyanates via electrophilic selenocyanogen cyclization was established. This sequential process was conducted under mild conditions in a short time. This protocol was successfully applied to late-stage functionalization of bioactive molecules. Notablely, the selenocyanate can be converted into other valuable