Kinetic study of methoxide-promoted elimination reactions of some 1,1,1-trichloro-2,2-bis(phenyl-substituted)ethanes

The methoxide-promoted elimination reaction of some 1,1,1-trichloro-2,2-bis(phenyl-substituted)ethanes (1) was investigated. The ortho-substituted derivatives were found to be less reactive than the corresponding ortho-unsubstituted derivatives, irrespective of the nature of their substituent. The reactivity data were correlated with the ¹³C NMR chemical shift values of C-β of either 1,1,1-trichloro-2,2-bis(phenyl-substituted)ethanes or 1,1-dichloro-2,2-bis(phenyl-substituted)ethenes and the better result was obtained for the former correlation. Activation parameters for the methoxide-promoted elimination of 1 show very similar values for ortho-substituted derivatives. The total data set seems to be more indicative, even if not compelling, of an irreversible E1cB mechanism. Copyright © 2001 John Wiley & Sons, Ltd.