124286-46-0Relevant articles and documents
Photochemical generation of radicals from alkyl electrophiles using a nucleophilic organic catalyst
Schweitzer-Chaput, Bertrand,Horwitz, Matthew A.,de Pedro Beato, Eduardo,Melchiorre, Paolo
, p. 129 - 135 (2018/12/13)
Chemists extensively use free radical reactivity for applications in organic synthesis, materials science, and life science. Traditionally, generating radicals requires strategies that exploit the bond dissociation energy or the redox properties of the precursors. Here, we disclose a photochemical catalytic approach that harnesses different physical properties of the substrate to form carbon radicals. We use a nucleophilic dithiocarbamate anion catalyst, adorned with a well-tailored chromophoric unit, to activate alkyl electrophiles via an SN2 pathway. The resulting photon-absorbing intermediate affords radicals upon homolytic cleavage induced by visible light. This catalytic SN2-based strategy, which exploits a fundamental mechanistic process of ionic chemistry, grants access to open-shell intermediates from a variety of substrates that would be incompatible with or inert to classical radical-generating strategies. We also describe how the method’s mild reaction conditions and high functional group tolerance could be advantageous for developing C–C bond-forming reactions, for streamlining the preparation of a marketed drug, for the late-stage elaboration of biorelevant compounds and for enantioselective radical catalysis.
Radical and Ionic Reactions of (Benzoylmethyl)mercurials
Russell, Glen A.,Kulkarni, Shekhar V.,Khanna, Rajive K.
, p. 1080 - 1086 (2007/10/02)
Photolysis of PhCOCH2HgCl or (PhCOCH2)2Hg yields benzoylmethyl radicals which can be trapped by anions such as Me2C=NO2-, RC(CO2Et)2-, RC(O-)=CH2 or by other electron-rich systems such as (RO)3P, N-methylpyrrole, enamines, or norbornene.Electron transfer from the adduct radicals to the mercurials yields PhCOCH2A from the anions A-, PhCOCH2P(O)(OR)2 from P(OR)3, and the phenacyl derivative from N-methylpyrrole or enamines.Easily oxidized anions such as PhCOCPh2- or PhC(CH3)=NO2- react with PhCOCH2* by electron transfer to yield the dimer derived from the anion.Addition of PhCOCH2* to norbornene yields a substituted 3-benzoylpropyl radical which cyclizes at the ortho position of the benzoyl group to give the α-tetralone derivative.
