Invariance of electrophilicity of independent fragments. Application to intramolecular Diels-Alder reactions

► The fragment elecrophilicity shows a remarkable stability. ► The empirical reactivity rules for intermolecular DA are transferred to IMDA. ► Fragment independent model separate the molecular electrophilicity of the D and Dp. ► The electrophilicity is an invariant property for fragments embedded in different molecules.