The first Diels–Alderreaction of vinyl arenes with ene systems catalyzed by MOFs is reported. Maleimides and maleicanhydride were annulated/dehydrogenated on styrenes in the presence of a mixed-metal (FeNi)MIL-88A catalyst. Neither an additional oxidant nor a source of halogen is needed to drive this oxidative [4 + 2] cyclization reaction. Kinetic evidence such as activation entropy corroborates