A rationalization of orientation and reactivity in the nucleophilic replacement reactions of aromatic polyhalo-compounds |
| |
Authors: | J Burdon |
| |
Institution: | Chemistry Department, The University, Birmingham, 15 U.K. |
| |
Abstract: | C6F5X compounds react with nucleophiles at the position para to X in some cases (X = H, CH3, NMe2, SMe, CF3), meta in others (X = NH2, O−) and occasionally at both meta and para in comparable amounts (X = OMe, NHME); significant amounts of ortho-replacement also occur (X = Cl, OMe). These orientations, and those in polychloro-aromatics and polyfluoro-polynuclear aromatics, can be rationalized by considering the relative stabilities of the Wheland-type intermediates involved (I, II, III), provided the halogens are taken as electron-repelling in π-systems. Reactivities can be rationalized if ground state stabilities are considered as well. A number of predictions have been made on the basis of these arguments. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|