2-bromobenzenesulfonic acid phenyl esters

Doucet and coworkers reported the intramolecular coupling reaction of 2-bromobenzenesulfonic acid phenyl esters in the presence of a phosphine-free palladium catalyst (Scheme 4.16) [23]. One mole percentage of phosphine-free Pd (OAc)2 as the catalyst associated to KOAc promoted the intramolecular direct arylation via an sp C-H bond functionalization of several 2-bromobenzenesulfonic acid derivatives. The nature of the substituents on the phenol moiety was found to have a huge influence on the reaction. Electron-donating substituents favored the reaction, whereas electron-withdrawing substituents are unfavorable. As a very wide variety of phenols are commercially available, such a cyclization would provide a very simple access to functionalized sultones. 

Scheme 4.16 Pd-catalyzed intramolecular coupling reaction of 2-bromobenzenesulfonic acid phenyl esters.

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See also in sourсe #XX -- [ ]

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