Diels-Alder reactions between hexafluoro-2-butyne and bis-furyl dienes: kinetic versus thermodynamic control

The tandem [4+2] cycloaddition between hexafluoro-2-butyne and bis-furyl dienes, like difurfuryl ester, at room temperature leads to the kinetically controlled pincer''-adducts - annulated 4a, 8a-bis(trifluoromethyl) hexahydro-1,4: 5,8-diepoxynaphthalenes. On the other hand, if these reactions proceed at 140 degrees C, only the thermodynamically controlled domino''-adducts - annulated 2,3-bis(trifluoromethyl) hexahydro-1,4: 5,8-diepoxynaphthalenes - are formed. Therefore, a very rare and unexpected example of full kinetic and thermodynamic control in the Diels-Alder reaction is reported in this paper.