'On water synthesis' of oxindoles bearing quaternary carbon center through C-H (sp³) functionalization of methyl azaarenes

A catalyst-free and green approach of sp³ C-H functionalization of methyl azaarenes with malononitrile and isatins for the synthesis of oxindole derivatives bearing quaternary carbon center has been described in water. This one-pot three component synthesis endures the key features like first 'on water synthesis', short reaction times, moderate to good yields, and large substrate scope.