BF3·OEt2 Mediated Regioselective Reaction of Electron-Rich Arenes with 3-Ylidene Oxindoles.

A BF3·OEt2 mediated novel and regioselective protocol for the construction of a C-C bond between 3-ylidene oxindoles and electron-rich arenes has been successfully accomplished. The reaction was compatible with a wide variety of electron-rich arenes. A cascade reaction of 3-ylidene oxindoles with phenols and β-naphthol resulted in 2,3-difunctionalized benzofuran and lactone bearing indoline-2-one scaffolds under same conditions.