Iodine(III)-Mediated Unexpected Ring-Contraction Rearrangement and Halogenated Addition Reaction to Synthesize 3-Substituted Phthalides and Isochroman-1-One Derivatives

Iodine(III)-mediated ring-contraction rearrangement and halogenated addition reaction have been realized. A series of 3-substituted phthalides and isochroman-1-one derivatives bearing multiple functional groups were obtained in good to excellent yields under mild reaction conditions. Computational studies indicated that the reaction proceeds via a proton transfer followed by ring opening and ring formation to produce the target product. Moreover, preliminary biological evaluations revealed that both of 3-substituted phthalides and isochroman-1-one derivatives show good antitumor activities.