Local reactivity descriptors of the important atoms in chelotropic reactions provide insight into their global variants along the reaction path

Chelotropic reactions are widely used in organic synthesis. These reactions are of the pericyclic type where a p bond and a lone pair are transformed into a pair of sigma bonds; with both sigma bonds added to the same atom. This work presents an analysis of several representative chelotropic reactions. To study the reaction path, we have divided it into two parts, from the reactants to the transition state and from the transition state to the products which has allowed us to compare the behavior of the reactants in these two ranges of the path. To perform the analysis, global reactivity descriptors based on the conceptual-density functional theory (DFT), such as electrophilicity and global softness, have been calculated. To analyze these descriptors, the corresponding local descriptors have been used. A model based on Sanderson's principle (electronegativity equalization principle), developed previously, has been used to calculate the local reactivity descriptors (atomic). The statistical methodology of multiple regression analysis has been used to determine which local variables are the most relevant for the global parameter under study (softness, and electrophilicity), also the principal component analysis has been used as a guide to estimate the number of variables to take into account in the analysis, finally this has led us to important correlations between global and local parameters which has allowed us to analyze the reactions of the study. Transition states of the reactions are aromatic as obtained from the nucleus independent chemical shift (NICS) and gauge including magnetically induced ring current (GIMIC) analysis.