Activity of Organic Superbase <i>t</i> ‐Bu‐P4/DMSO in <i>C</i> ‐Vinylation of Ketones with Acetylenes: A Theoretical Study

Abstract This work explores the potential applications of organic phosphazene superbases in the C ‐vinylation reaction, a process typically associated with inorganic superbases such as MO t ‐Bu/DMSO and MOH/DMSO (M = K, Na). For the first time, the mechanism of C ‐vinylation of acetone with phenylacetylene in the presence of t ‐Bu‐P4/DMSO was studied using quantum chemical methods. It has been demonstrated that in the presence of both the organic base t ‐Bu‐P4 and the inorganic bases KO t ‐Bu or KOH, thermodynamically more stable C ‐vinylation products are formed from kinetically preferred ethynylation products. The activation barriers for this transformation in the t ‐Bu‐P4/DMSO and KO t ‐Bu/DMSO systems are similar and estimated to be about 30 kcal/mol, while in the KOH/DMSO system, they are higher. These activation barrier values suggest that the C ‐vinylation reaction of acetone with phenylacetylene could be carried out in the presence of t ‐Bu‐P4 at high temperatures, above 80 °C.