Plausible pathway for IH catalyzed hydro-
thiolation/selenation reaction
A plausible pathway has been proposed for the Imidazol-2-ylidene (IH)
catalyzed hydro- thiolation/selenation reaction (Scheme 1) which makes
use of the high Bronsted basicity of NHCs in initiating the reaction.
NHC can abstract the thiolic or acetylenic proton, but our computations
proved acetylenic activation by NHC to be a much more energy consuming
process (by 16.81 kcal/mol at B3LYP/6-31+G(d) level). This indicated
that the given proposed pathway proceeding through thiol activation
would be more feasible.
Scheme 1 Envisioned pathway for NHC catalyzed acetylene
hydrochalcogenation reaction