A new paradigm in the coupling of external alkenes with internal electron-deficientalkenes has been investigated in which an unprecedented annulation of vinylarenes on maleimides takes place. The reaction is carried out via a tandem in situ activation of both olefinic and aromatic C–H bonds of styrenes driving the reaction in a pseudo-Diels–Alder mode.
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