and cyclobutanes via radical chemistry is described. The method that generally proceeds in high yields uses epoxides as radical precursors and titanocene(III) complexes as the electron transfer catalysts (see scheme). The key to the success of the transformation is constituted by the chemoselectivity of radical reduction. Electrophilic enol radicals generated through cyclization are reduced rapidly
parent butenyl radical, and in bond dissociation energy (BDE) calculations. The BP86 method using density fitting, and a basis set of triple-zeta quality emerged as a highly reliable tool for studying titanocene mediated radicalreactions. The computational results revealed important kinetic and thermodynamic features of cyclopropane formation. Surprisingly, the beta-titanoxy radicals, the first intermediates