Stereoselectivities and reaction rates in Diels-Alder reactions promoted by non-aqueous solvents and their aqueous mixtures: Correlations with non-adjustable parameters

Abstract

Stereoselectivities and rates of Diels-Alder reactions in different solvents were correlated with a parameter, Q, defined based on internal pressure, which is normalized with respect to a polarity scale. The polarity scale or index, although purely empirical in nature, can be calculated from the refractive index of the solvent. These correlations were linear for both stereoselectivities and reaction rates. Using expressions derived in this study, it is possible to represent the kinetic profiles of several Diels-Alder reactions in about 75 pure and mixed solvent media. The activation volume of a reaction can be directly estimated from the regression of data on rates and Q in various solvents using the proposed correlations.