Chelation assistance as a tool for the selective preparation of an imidazole-based mesoionic palladium carbene complex

Chem Commun (Camb). 2014 Dec 18;50(97):15313-5. doi: 10.1039/c4cc07732f. Epub 2014 Oct 27.

Abstract

A C(4)-bound palladium-N-heterocyclic carbene (4) was selectively obtained from the C(2)-unsubstituted imidazolium salt 3. The higher stability of the C(4) versus the C(2)-bound carbene complex due to pyridine chelation assistance allowed this mesoionic compound to be obtained.