Evidence for merging of mechanism in competing S N 2 and E2 processes

Abstract
Dissected ratios kOTs/kBr(SN2) and kOTs/kBr(E2) for competing substitution and elimination, respectively, have been determined for alkoxide ion (EtO/EtOH and ButO/ButOH) promoted reactions of simple alkyl derivatives RX (R = Me, Et, Prn, Bui, or Neopen; X = OTs, or Br). The ratios are shown to be severely distorted when compared with those for pure substitutions and pure eliminations. In general, a rise in kOTs/kBr(SN2) is coupled with a fall in kOTs/kBr(E2). The observed distortion is consistent with the hypothesis that alkoxide ion promoted SN2 and E2 reactions are not completely independent processes. A merged type mechanism is suggested, in which alkoxide ion interacts with both Cα and Hβ before partitioning to SN2 and E2 transition states occurs.

This publication has 0 references indexed in Scilit: