Ruthenium-catalyzed intramolecular cyclization of diazo--ketoanilides for the synthesis of 3-alkylideneoxindolesElectronic supplementary information (ESI) available: 1H and 13C NMR spectra. See DOI: 10.1039/c2ob06985g

With [Ru( p -cymene)Cl 2 ] 2 as catalyst, diazo--ketoanilides would undergo intramolecular carbenoid arene CH bond functionalization to afford 3-alkylideneoxindoles in up to 92% yields. The reaction occurs under mild conditions and exhibits excellent chemoselectivity. The lack of primary KIE ( k H / k D 1) suggests that the reaction should not proceed by rate-limiting CH bond cleavage; a mechanism involving cyclopropanation of the arene is proposed. With [Ru( p -cymene)Cl 2 ] 2 as catalyst, diazo--ketoanilides would undergo intramolecular carbenoid arene CH bond functionalization to afford 3-alkylideneoxindoles in up to 92% yields. The reaction occurs under mild conditions and exhibits excellent chemoselectivity.