Silver-Catalyzed Trifluoromethylalkynylation of Unactivated Alkenes with Hypervalent Iodine Reagents
作者:Xinkan Yang、Gavin Chit Tsui
DOI:10.1021/acs.orglett.9b03230
日期:2019.11.1
unactivated alkenes is presented. The reaction is catalyzed by silver(I) trifluoroacetate for the simultaneous construction of two C-C bonds (alkyl-alkyne and alkyl-CF3). By employing versatile hypervalentiodinereagents, ethynylbenziodoxolones, useful trifluoromethylalkynylated compounds can be prepared from simple alkenes displaying excellent functional group tolerability. A radical mechanism is proposed
Radical Pentafluoroethylation of Unactivated Alkenes Using CuCF<sub>2</sub>CF<sub>3</sub>
作者:Xinkan Yang、Gavin Chit Tsui
DOI:10.1021/acs.orglett.0c01646
日期:2020.6.5
source for the CF2CF3 radical under aerobic conditions at room temperature. Using this system, readily available unactivatedalkenes can be pentafluoroethylated to provide novel allylic CF2CF3 compounds with excellent E-selectivity and functional group tolerability. Mechanistic studies including TEMPO–CF2CF3 trapping and radical clock experiments provided strong evidence for radical pathways, offering
the vancomycin structure. Herein, we describe the development of synthetic technology based on the design of a novel selenium safety catch linker, application of this technology to a solid-phase semisynthesis of vancomycin, and the solid- and solution-phase synthesis of vancomycin libraries. Biological evaluation of these compound libraries led to the identification of a number of in vitro highly potent
convenient reaction for oxidative trifluoromethylation of terminal alkenes was developed using in situ generated AgCF3 in the presence of a copper catalyst. The reaction proceeded under an air atmosphere to afford trifluoromethylated allylic compounds in moderate to good yield. This reaction, with no need for highly hygroscopic or corrosive reagents, features not only a simple operation but also various functional
Trifluoromethylation of Unactivated Alkenes with Me<sub>3</sub>SiCF<sub>3</sub> and <i>N</i>-Iodosuccinimide
作者:Xinkan Yang、Gavin Chit Tsui
DOI:10.1021/acs.orglett.9b00332
日期:2019.3.1
A novel approach to the trifluoromethylation of unactivated alkenes is presented. This reaction is promoted by N-iodosuccinimide (NIS) undervisiblelight irradiation without the need for photocatalysts. The mild conditions allow the direct synthesis of useful trifluoromethylated (E)-alkenes from readily available alkene feedstocks with excellent functional group tolerability. In addition, using easy-to-handle