Construction of 2-Substituted-3-Functionalized Benzofurans via Intramolecular Heck Coupling: Application to Enantioselective Total Synthesis of Daphnodorin B
A novel approach was developed for the synthesis of 2-substituted-3-functionalized benzofurans, using an intramolecular Heckreaction which was further applied in the first enantioselectivetotalsynthesis of Daphnodorin B.
Synthesis of 2-sulfenylindenones by visible-light-mediated addition of sulfur-centered radicals to 1,3-diarylpropynones
作者:Chengqun Chen、Qian Xiong、Jie Wei
DOI:10.1080/00397911.2019.1580744
日期:2019.3.19
Abstract A novel, visible-light-mediated method for the synthesis of 2-sulfenylindenones from easily available thiophenols (2.0 equiv.) and 1, 3-diarylpropynones (1.0 equiv.) in the presence of eosin Y (0.02 equiv.) under air atmosphere has been developed. The reaction proceeded smoothly, for a wide range of derivatives of thiophenols and 3-diarylpropynones, to give the expected products in moderate
Base-mediated benzannulation of α-cyanocrotonates with ynones: facile synthesis of benzonitriles and fluorenes
作者:Maneesh Kumar Reddy Singam、Attunuri Nagireddy、Sridhar Reddy Maddi
DOI:10.1039/d0gc00608d
日期:——
Benzonitriles and cyanofluorenes have been rapidly obtained via the [3 + 3] benzannulation of readily available alkynones and α-cyanocrotonates using KOtBu as the only reagent and EtOH (and CO2) is the only by-product.
The metal-free oxidative alkene methylation/alkynylation of 1,4-enyn-3-ols with an organic peroxide as the methyl source has been developed, which provides straightforward and practical access to the challenging quaternary-carbon-containing but-3-yn-1-ones. The method is reasoned to go through methylation of functional alkenes utilizing dicumyl peroxide as the methylating reagent and subsequent intermolecular
(HAT) strategies within the framework of photoredox catalysis is highly appealing for its power to activate a desired C−H bond in the substrate leading to its selective functionalization. Reported here is the first photoredox‐mediated hydrogen‐atom transfer method for the efficient synthesis of ynones, ynamides, and ynoates with high regio‐ and chemoselectivity by direct functionalization of C (O)−H