Palladium-catalyzed intramolecular direct arylation of 2-bromobenzenesulfonic acid derivatives.

International audienceA palladium-catalyzed intramol. direct arylation of 2-bromobenzenesulfonic acid derivs. was found to proceed using 1 mol% of palladium acetate as the catalyst. The influence of the substituents on the phenol moiety of 2-bromobenzenesulfonic acid Ph esters reveals that electron-donating substituents favor the reaction while electron-withdrawing ones are unfavorable. The reactivity of sulfonamides was also studied and, in all cases, a selective activation at sp2 C-H vs. sp3 C-H was obsd. A sulfonamide bearing both Ph and benzyl substituents on nitrogen gave selectively the six-membered ring product. [on SciFinder(R)