Abstract
The gas phase reactivity of N‐heterocyclic carbenes versus tricyclohexylphosphine (PCy3) is examined computationally and experimentally. New measurements indicate that dimethylimidazol‐ and 1‐ethyl‐3‐methylimidazol‐2‐ylidene are more basic than PCy3, in contrast to previous measurements made by us and by others. Proton‐bound dimers of the carbenes and PCy3 are also found to exhibit interesting reactivity involving phosphine alkylation, cyclohexene elimination, and/or ethylene elimination. This novel reactivity is further probed and discussed. Copyright © 2011 John Wiley & Sons, Ltd.
Gas phase studies of N‐heterocyclic carbenes reveal unexpected reactivity and surprising proton affinities.