Iridium-Catalyzed Intramolecular Methoxy C−H Addition to Carbon-Carbon Triple Bonds: Direct Synthesis of 3-Substituted Benzofurans from <i>o</i>
-Methoxyphenylalkynes
Catalytic hydroalkylation of an alkyne with methyl ether was accomplished. Intramolecular addition of the C−H bond of a methoxy group in 1‐methoxy‐2‐(arylethynyl)benzenes across a carbon–carbontriple bond took place efficiently either in toluene at 110 °C or in p‐xylene at 135 °C in the presence of an iridium catalyst. The initial 5‐exo cyclization products underwent double‐bond migration during the
BCl<sub>3</sub>
-Induced Annulative Oxo- and Thioboration for the Formation of C3-Borylated Benzofurans and Benzothiophenes
作者:Andrew J. Warner、Anna Churn、John S. McGough、Michael J. Ingleson
DOI:10.1002/anie.201610014
日期:2017.1.2
form synthetically ubiquitous pinacol boronate esters or used in situ in Suzuki-Miyauracrosscouplings to generate 2,3-disubstituted heteroarenes from simple alkyne precursors in onepot. In a number of cases alkyne trans-haloboration occurs alongside, or instead of, borylative cyclization and the factors controlling the reaction outcome are determined.
FeCl<sub>3</sub>-Diorganyl Dichalcogenides Promoted Cyclization of 2-Alkynylanisoles to 3-Chalcogen Benzo[<i>b</i>]furans
作者:Rafaela M. Gay、Flávia Manarin、Caroline C. Schneider、Daniela A. Barancelli、Michael D. Costa、Gilson Zeni
DOI:10.1021/jo101126q
日期:2010.8.20
2-alkynylanisoles, via FeCl3/diorganyl dichalcogenides intramolecular cyclization, has been developed. Aryl and alkylgroups directly bonded to the chalcogen atom were used as cycling agents. The results revealed that the reaction significantly depends on the electronic effects of substituents in the aromatic ring bonded to the selenium atom of the diselenide species. We observed that the pathway of reaction was
通过FeCl 3从容易获得的2-炔基苯甲醚中合成3-硫属元素苯并[ b ]呋喃/ diorganyl dichalcogenides分子内环化已得到开发。直接结合到硫属元素原子上的芳基和烷基用作循环剂。结果表明,该反应显着取决于与二硒化物物种的硒原子键合的芳环中取代基的电子效应。我们观察到反应途径对苯甲醚芳环中取代基的性质不敏感,因为给电子基团和吸电子基团均以相似的产率传递产物。此外,将得到的杂环被容易地通过使用与硫属/锂交换反应转化成更复杂的产品Ñ-BuLi,然后用醛截留锂中间体,以良好的产率提供所需的仲醇。
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。
A Green and Efficient Approach for the Synthesis of 3-Chalcogen Benzo[<i>b</i>]Furans <i>via</i> I<sub>2</sub>-Mediated Cascade Annulation Reaction of 2-Alkynylanisoles at Room Temperature in Water
Abstract An efficient and green aqueous protocol to access 3-chalcogen benzo[b]furan derivatives has been developed. The reaction can proceed via I2-mediated intramolecular annulationreaction of 2-alkynylanisoles with diaryl disulfides (diselenides) in water or undersolvent-freeconditions at room temperature. With the participation of I2, a variety of 3-chalcogen benzo[b]furan derivatives were obtained