Arylation reactions: the photo-S(N)1 path via phenyl cation as an alternative to metal catalysis.
Photo(sensitized) cleavage of benzenediazonium salts as well as, when an electron-donating substituent is present, of aryl chlorides, fluorides, mesylates, triflates, and phosphates leads to the corresponding phenyl cations in the triplet state. These otherwise unavailable intermediates add selectively to alkenes, alkynes, and (hetero)arenes, giving arylation products in a good yield. The reactions are photochemical alternatives of metal-catalyzed Heck and cross-coupling reactions and bear some mechanistic analogy with them.
Fagnoni
Maurizio
M
Department of Organic Chemistry, University of Pavia, via Taramelli 10, 27100 Pavia, Italy.
Albini
Angelo
A
D000215:Acylation; D001555:Benzene Derivatives / Q000737:chemistry*; D002384:Catalysis; D002412:Cations; D002712:Chlorides / Q000737:chemistry; D003979:Diazonium Compounds / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry; D006846:Hydrocarbons, Halogenated / Q000737:chemistry*; D008698:Mesylates / Q000737:chemistry; D008670:Metals / Q000737:chemistry*; D008956:Models, Chemical; D010710:Phosphates / Q000737:chemistry; D010777:Photochemistry
D001555:Benzene Derivatives; D002412:Cations; D002712:Chlorides; D003979:Diazonium Compounds; D006846:Hydrocarbons, Halogenated; D008698:Mesylates; D008670:Metals; D010710:Phosphates; C012077:trifluoromethanesulfonic acid; D005459:Fluorides