Meng, Guangrong published the artcileA simple 1H NMR method for determining the σ-donor properties of N-heterocyclic carbenes, HPLC of Formula: 258278-25-0, the publication is Tetrahedron Letters (2019), 60(4), 378-381, database is CAplus.
The σ-donor properties of NHC ligands (NHC = N-heterocyclic carbene) are crucial in controlling their interaction with transition metals, and as a consequence, to determine the selectivity and reactivity of NHCs in transition-metal-catalysis. Herein, we report a simple NMR method for estimating the σ-donor properties of NHC ligands based on a straightforward 1H NMR measurement of ligand precursors. We present evaluation of σ-donating properties for a range of NHC ligands varied by structure and electronics that are relevant to transition-metal-catalysis. We expect that the simple measurement of σ-donating properties of NHCs, together with the known methods for evaluating sterics and π-backbonding, will enhance the understanding of the properties of NHCs in transition-metal-catalysis.
Tetrahedron Letters published new progress about 258278-25-0. 258278-25-0 belongs to imidazoles-derivatives, auxiliary class Achiral NHCs Ligands, name is 1,3-Bis(2,6-diisopropylphenyl)-4,5-dihydro-1H-imidazol-3-ium chloride, and the molecular formula is C27H39ClN2, HPLC of Formula: 258278-25-0.
Referemce:
https://en.wikipedia.org/wiki/Imidazole,
Imidazole | C3H4N2 – PubChem