Palladium catalyzed bis - functionalization of isatylidenes: A facile route towards synthesis of spiro-functionalized oxindoles
Oxindoles incorporating a stereogenic center at C3 are challenging targets for chemical synthesis, as they are common motifs in natural products and pharmaceutically active compounds. Moreover 3,3-disubstituted oxindoles have shown promising biological activity. Therefore a number of synthetic methods have been developed in pursuit of this structure, Amphiphilic bis-?-allyl palladium and related intermediates were effectively utilized for the quarternization of C-3 position of oxindole towards disubstituted functionalized oxindoles (Eur. J. Org. Chem. 2010, in press). These products were subjected to ring closing metathesis towards the synthesis of 3-spirocyclohexenyl oxindoles and 3-spirooxepenyl oxindoles which are of biological interest.
Chemical Sciences and Technology