[4+2] Dimerization of Arylmaleic Acids Imides on Solid Media

The [4+2] dimerization of arylmaleic acid imides, which occurs in the presence of 3,5-dimethyl-1H-pyrazole on solid media under convection or microwave heating, has been studied. It was shown that dimerization proceeds stereoselectively with the formation of polycyclic compounds with a decahydrobenzo[e]pyrrolo[3,4-g]isoindole skeleton, predominantly of the endo-configuration. The best results in yields and stereoselectivity were achieved when reactions were carried out on silica gel under microwave activation conditions.