Silver-promoted, palladium-catalyzed direct arylation of cyclopropanes: facile access to spiro 3,3'-cyclopropyl oxindoles.

The Pd-catalyzed, Ag(I)-mediated intramolecular direct arylation of cyclopropane C-H bonds is described. Various spiro 3,3'-cyclopropyl oxindoles can be obtained in good to excellent yields from easily accessible 2-bromoanilides. The kinetic isotope effect was determined and epimerization studies were conducted, suggesting that the formation of a putative Pd-enolate is not operative and that the reaction proceeds via a C-H arylation pathway.