A theoretical study on the stereoconvergency of the intramolecular radical cation [2+2] cycloadditions of bis(styrenes)

Abstract

The intramolecular radical cation [2+2] cycloadditions of a series of bis(styrenes) have been explored by DFT (U)B3LYP method in conjunction with the 6-31G(d,p) and 6-311G(d,p) basis sets. According to our calculations, the pathway of the cycloaddition is stepwise via the formation of a 5-membered ring intermediate. The final cyclobutane products are formed by electron transfer between the long-bond radical cation product and the neutral reactant. The understanding of the mechanism gives a new insight into the stereoconvergency of the cycloaddition.