3,3-Bis(hydroxyaryl)oxindoles and Spirooxindoles Bearing a Xanthene Moiety: Synthesis, Mechanism, and Biological Activity

A facile and efficient methanesulfonic acid-catalyzed,
solvent-free,
microwave-assisted method was developed for the synthesis of biologically
active 3,3-bis(hydroxyaryl)oxindoles and spirooxindoles bearing a
xanthene moiety. The scope of the procedure was investigated with
a wide range of isatin and phenol derivatives; moreover, the reaction
mechanism was studied by density functional theory calculations. Both
3,3-bis(hydroxyaryl)oxindoles and spirooxindoles bearing a xanthene
moiety synthesized were evaluated for their anticancer and antimicrobial
activity, and most of them showed promising or significant activity
on six cancer cell lines and against Gram-positive bacteria.