Diels–Alder reactions between hexafluoro-2-butyne and bis-furyl dienes: kinetic <i>versus</i> thermodynamic control

Abstract

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 °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.