Synthesis of a Doubly Strapped Light-Harvesting Porphyrin Bearing Energy Donor Molecules Hanging on to the Straps: An Attempt toward Macroscopic Control over Molecular Conformation that Affects the Efficiency of Fluorescence Resonance Energy Transfer
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
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
Visible-Light-Promoted Iododifluoromethylation of Alkenes via (Phosphonio)difluoromethyl Radical Cation
作者:Alexey L. Trifonov、Liubov I. Panferova、Vitalij V. Levin、Vladimir A. Kokorekin、Alexander D. Dilman
DOI:10.1021/acs.orglett.0c00604
日期:2020.3.20
unactivated alkenes mediated by peri-xanthenoxanthene under blue-light irradiation is described. The reaction proceeds via activation of the carbon-iodine bond to generate (phosphonio)difluoromethyl radicalcation, which attacks the double bond with subsequent quenching by the iodine. The intermediate phosphonium salts are easily hydrolyzed, furnishing products of iododifluoromethylation of alkenes.
Operationally simple hydrotrifluoromethylation of alkenes with sodium triflinate enabled by Ir photoredox catalysis
作者:Lei Zhu、Lian-Sheng Wang、Bojie Li、Boqiao Fu、Cheng-Pan Zhang、Wei Li
DOI:10.1039/c6cc01944g
日期:——
We reported herein a single component of Ir-photoredox catalyst is capable to catalyze hydrotrifluoromethylation of terminal alkenes and Michael acceptors with sodium triflinate (Langlois reagent) in methanol under an irradiation...