Detailed analysis for the solvolysis of isopropenyl chloroformate

Malcolm John D’Souza, Kevin Edward Shuman, Arnold Ochieng Omondi, Dennis Neil Kevill

Abstract


The specific rates of solvolysis (including those obtained from the literature) of isopropenyl chloroformate (1) are analyzed using the extended Grunwald-Winstein equation, involving the NT scale of solvent nucleophilicity (S-methyldibenzothiophenium ion) combined with a YCl scale based on 1-adamantyl chloride solvolysis. A similarity model approach, using phenyl chloroformate solvolyses for comparison, indicated a dominant bimolecular carbonyl-addition mechanism for the solvolyses of 1 in all solvents except 97% 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). An extensive evaluation of the outcomes acquired through the application of the extended Grunwald-Winstein equation resulted in the proposal of an addition-elimination mechanism dominating in most of the solvents, but it is proposed that a superimposed unimolecular (SN1) type ionization is making a significant contribution in 97-70% HFIP, and 97% 2,2,2-trifluoroethanol (TFE).2_2_130_135_800


Keyword(s)


Solvolysis; Grunwald-Winstein equations; Isopropenyl chloroformate; Chlorocarbonate; Addition-elimination; Ionization

European Journal of Chemistry, 2 (2), (2011), 130-135

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DOI: http://dx.doi.org/10.5155/eurjchem.2.2.130-135.405