A DFT Study of the Reactivity Indexes of Ionic [4 + 2+] Diels-Alder Cycloaddition to Nitrilium and Immonium Ions

Abstract

Abstract:The global electrophilicity index, defined within the conceptual density functional theory (DFT), was used to classify the dienes and dienophiles currently used in Diels-Alder reactions on a unique scale of electrophilicity. The index, obtained within the Kohn-Sham scheme, is based on the HOMO and LUMO energies. A systematic study of the global reactivity indexes of the reagents involved in formal [4 + 2 + ] Diels-Alder cycloaddition reactions of nitrilium and immonium ions with isoprene is presented.

Computational Studies of 1,3-Dipolar [3 + 2]-Cycloaddition Reactions of Fullerene-C60 with Nitrones

“…By definition, it encompasses both the ability of an electrophile to acquire additional electronic charge and the resistance of the system to exchange electronic charge with the environment. Global electrophilicity, chemical hardness and chemical potential are very important global reactivity descriptors for studying the chemical reactivity and site selectivity of various molecular systems [26][27][28]. In view of the above, this work aims at exploring (1) mono-and bis-1,3-dipolar cycloaddition of nitrone and its substituted derivatives to fullerene C 60 (Scheme 2); (2) the effect of electron-releasing (CH 3 , CH 2 CH 3 , CH 2 CH 2 CH 3 , C 6 H 5 CH 2 ) substituents and electron-withdrawing substituents (F, Cl, Br, NC, and NO 2 -) on the energetics of the reaction; (3) the regio-and stereo-selectivity of the mono-and bis-addition and (4) global reactivity descriptors of the molecular systems to rationalize and predict their chemical reactivity and site selectivity.…”