Search for High Reactivity and Low Selectivity of Radicals toward Double Bonds: The Case of a Tetrazole-Derived Thiyl Radical

The search for new radical structures having both low selectivity and high reactivity toward the addition reaction onto alkenes can be of interest in organic synthesis or polymer chemistry and has led us to propose a new tetrazole-derived thiyl radical. The reactivity of this sulfur-centered structure is compared to that of an aminoalkyl radical also efficient for alkene addition Worthwhile results are obtained; the new structure is more reactive on the complete range of alkenes with addition rate constants higher than 107 M(-1) s(-1) for both electron-deficient (acrylonitrile, ...) or electron-rich (vinylether, ...) double bonds. Quantum mechanical calculations have allowed a better understanding of this unique feature.