Radical additions to some strained organic molecules

Abstract

The existence of a cyclopropabenzyl radical has not been established. Reactions between cyclopropabenzene Breslow, R., Groves, J.T., and Ryan, G., J. Am. Chem. Soc., 1967, 89, 5048; Breslow, R., and Groves, J.T., J. Am. Chem. Soc., 1970, 92, 984. and radical species result in opening of the three-membered ring. The present study employed 1H-cyclopropa[b]naphthalene Banwell, M.G., Battner, R., Browne, A.R., Craig, J.T., and Halton, B., J. Chem. Soc., Perkin Trans.1, 1977, 1, 2165. and its 1 -phenylmethylene- and 1 -diphenylmethylene derivatives (70a) and (70b), respectively, as substrates for reactions with a variety of radicals with a view to gaining evidence for the existence of the C1 cycloproparenyl radical. This study has provided no evidence to support the existence of a cycloproparenyl radical. 1H-Cyclopropa[b]naphthalene Banwell, M.G., Battner, R., Browne, A.R., Craig, J.T., reacts with N-bromo-succinimide, sulfuryl chloride, and iodine to give the 2-substituted 3-(substituted-methyl)naphthalenes Gover, and Willard, J. Am. Chem. Soc., 1960, 82, 3816., March, J., Advanced Organic Chemistry - Reaction, Mechanisms, and Structure, 4th Ed., John Wiley and Sons, New York, 1992, 691. Cook, E.S., and Hill, A.J., J. Am. Chem. Soc., 1940, 62, 1995., At this point in the reaction, mixture was found to react very vigorously and escape the containing vessel. Extreme caution should be taken here. ,(137). Arylthiols produce compounds March, J., Advanced Organic Chemistry - Reaction, Mechanisms and Structure, 4th Ed., John Wiley and Sons, New York, 1992, 691.- Krafft, F., and Vorster, W. Ber., 1893, 26, 2831., and tributyltin hydride gives (131) from highly regioselective opening of the three membered ring of Banwell, M.G., Battner, R., Browne, A.R.,Craig, J.T., and Halton, B., J. Chem. Soc., Perkin Trans. 1, 1977, 1, 2165. Similar radical reactions with 1 -phenylmethylene-and 1-diphenylmethylene-1H-cyclopropa[b]naphthalene, (70a) and (70b), failed to provide characterisable products.