4703-02-0Relevant articles and documents
Direct Photoexcitation of Ethynylbenziodoxolones: An Alternative to Photocatalysis for Alkynylation Reactions**
Amos, Stephanie G. E.,Cavalli, Diana,Le Vaillant, Franck,Waser, Jerome
supporting information, p. 23827 - 23834 (2021/09/25)
Ethynylbenziodoxolones (EBXs) are commonly used as radical traps in photocatalytic alkynylations. Herein, we report that aryl-substituted EBX reagents can be directly activated by visible light irradiation. They act as both oxidants and radical traps, alleviating the need for a photocatalyst in several reported EBX-mediated processes, including decarboxylative and deboronative alkynylations, the oxyalkynylation of enamides and the C?H alkynylation of THF. Furthermore, the method could be applied to the synthesis of alkynylated quaternary centers from tertiary alcohols via stable oxalate salts and from tertiary amines via aryl imines. A photocatalytic process using 4CzIPN as an organic dye was also developed for the deoxyalkynylation of oxalates.
Iminyl-Radicals by Oxidation of α-Imino-oxy Acids: Photoredox-Neutral Alkene Carboimination for the Synthesis of Pyrrolines
Jiang, Heng,Studer, Armido
supporting information, p. 12273 - 12276 (2017/09/11)
The visible-light-promoted decarboxylation of α-imino-oxy propionic acids for the generation of iminyl radicals has been accomplished through the use of Ir(dFCF3ppy)2(dtbbpy)PF6 as a photoredox catalyst. Different from visible-light-promoted homolysis and single-electron reduction of oxime derivatives, this strategy provides a novel catalytic cycle for alkene carboimination through a sequence comprising N-radical generation, iminyl radical cyclization, intermolecular conjugate addition to a Michael acceptor, and single-electron reduction to afford various pyrroline derivatives in an overall redox-neutral process. The indolizidine alkaloid skeleton could be easily constructed from a pyrroline derivative prepared by this synthetic method.
