Synthesis of 4-Chloroisocoumarins via Intramolecular Halolactonization of o-Alkynylbenzoates: PhICl2-Mediated C–O/C–Cl Bond Formation
摘要:
A series of 4-chloroisocoumarins were conveniently synthesized from o-alkynylbenzoates via PhICl2-mediated intramolecular cyclization under metal-free conditions. PhICl2 plays the role of both the oxidant and the chlorine source to enable oxidative C-O bond formation and introduction of the chlorine atom. The utility and practicability of this protocol have been exemplified by virtue of mild reaction conditions, high-yielding products, simplified purification, and gram-scale synthesis.
Palladium-Catalyzed Decarboxylative Coupling of Alkynyl Carboxylic Acids with Benzyl Halides or Aryl Halides
作者:Wen-Wu Zhang、Xing-Guo Zhang、Jin-Heng Li
DOI:10.1021/jo1010284
日期:2010.8.6
synthesis of internal benzyl alkynes and 1,2-diarylalkynes has been developed via palladium-catalyzed decarboxylative coupling reactions of alkynyl carboxylic acids with benzyl chlorides or arylhalides. In the presence of Pd(OAc)2 and Xphos (L3), alkynyl carboxylic acids smoothly underwent the reaction with various benzyl halides, providing the corresponding benzyl alkynes in moderate to good yields. It
Palladium(II)-catalyzed tandem annulation reaction of o-alkynylbenzoates with methyl vinyl ketone for the synthesis of isocoumarins
作者:Huan Wang、Xiuling Han、Xiyan Lu
DOI:10.1016/j.tet.2013.07.057
日期:2013.10
A palladium(II)-catalyzed highly regioselective tandem reactions of o-alkynylbenzoates with methyl vinyl ketone for the synthesis of isocoumarins was developed. It is a convenient, mild and environmentally benign reaction with moderate to high yield. The reaction is initiated by the Pd(II) species and regenerate the Pd(II) species to complete the catalytic cycle without the necessity of a redox system
In Situ Formation of RSCl/ArSeCl and Their Application to the Synthesis of 4-Chalcogenylisocumarins/Pyrones from <i>o</i>-(1-Alkynyl)benzoates and (<i>Z</i>)-2-Alken-4-ynoates
作者:Linlin Xing、Yong Zhang、Bing Li、Yunfei Du
DOI:10.1021/acs.orglett.9b01046
日期:2019.5.17
diorganyl disulfides or diselenides with PhICl2 in acetonitrile was found for the first time to lead to the in situ formation of organosulfenyl chloride or selenenyl chloride, which enables the regioselective intramolecular chalcogenylacyloxylation of alkynes resulting in the formation of 4-chalcogenylisocumarins/pyrones in good to excellent yields under metal-free conditions.
Trifluoromethylthiolation/Selenolation and Lactonization of 2-Alkynylbenzoate: The Application of Benzyl Trifluoromethyl Sulfoxide/Selenium Sulfoxides as SCF<sub>3</sub>/SeCF<sub>3</sub> Reagents
作者:Haofeng Shi、Xingzong Wang、Xiaoxian Li、Beibei Zhang、Xuemin Li、Jingran Zhang、Jingyue Yang、Yunfei Du
DOI:10.1021/acs.orglett.2c00563
日期:2022.3.25
The combined use of BnS(O)CF3/BnSe(O)CF3 with Tf2O as SCF3/SeCF3 reagents was implemented to realize an efficient synthesis of biologically interesting 4-(trifluoromethylthio/trifluoromethylseleno)isocoumarins from 2-alkynylbenzoates. The mechanistic pathway was postulated to involve formation of the electrophilic SCF3/SeCF3 species via interrupted Pummerer reactions followed by a concerted triflu
Cy<sub>2</sub>NH·HX-Promoted Cyclizations of <i>o</i>-(Alk-1-ynyl)benzoates and (<i>Z</i>)-Alk-2-en-4-ynoate with Copper Halides to Synthesize Isocoumarins and α-Pyrone
作者:Jin-Heng Li、Yun Liang、Ye-Xiang Xie
DOI:10.1055/s-2006-958960
日期:2007.2
Cy 2 NH·HX was found to improve the cyclization reactions of o-(alk-1 -ynyl)benzoates and (Z)-alk-2-en-4-ynoate with CuX 2 (X = Cl, Br) to synthesize the corresponding 4-haloisocoumarins and 5-bromo-2-pyrone, respectively. In the presence of two equivalents of CuCl 2 , cyclization of methyl2-(2-phenylethynyl)benzoate was conducted smoothly to afford the corresponding desired product in 83% yield after