A boronate prochelator built on a triazole framework for peroxide-triggered tridentate metal binding

► Boronate-masked prochelator TIP is converted by H2O2 to tridentate chelator deferasirox. ► TIP does not bind Fe(III). ► TIP binds weakly to Cu(II). ► TIP and deferasirox are cytotoxic to ARPE cells. ► TIP and deferasirox protect ARPE cells against peroxide-induced cell death.