Abstract
The mechanism of the Horner-Wadsworth-Emmons (HWE) reaction has
been investigated using high level quantum mechanical calculations
on a realistic model system. The solvation contribution has been
evaluated using the PCM/DIR method. In the free, anionic system,
the rate determining step was found to be the ring closure of an
oxyanion to an oxaphosphetane. Solvation was found to have a
drastic influence on the reaction path. In most solvated systems,
the bimolecular formation of the oxyanion intermediate may be rate
limiting. Previously postulated isomerization side paths were
investigated. Several effects that could rationalize
experimentally observed trends for (E)/(Z)-selectivities have been
identified.
| Original language | English |
|---|---|
| Journal | Journal of organic chemistry |
| Volume | 63 |
| Pages (from-to) | 1280-1289 |
| Publication status | Published - 1998 |