Efficient synthesis of bulky N-Heterocyclic carbene ligands for coinage metal complexes

•Efficient synthesis of highly bulky N-heterocyclic carbenes were developed.•The synthesis involves three steps with ∼40% yield without column chromatography.•The free NHCs and coinage metal complexes were also isolated and characterized.

A facile and efficient route to synthesize sterically bulky N-heterocyclic carbenes with high percent buried volumes has been developed. The method involves three steps from commercial reagents and produced the NHC precursors with approximately 40% overall yield without column chromatography. The free carbenes were isolated as confirmed by X-ray crystallography and 13C NMR peak at 213 ppm corresponding to the carbene carbons. The Cu(I), Ag(I), and Au(I) chloride complexes supported by the NHC ligands were successfully synthesized and fully characterized including X-ray crystallography.

Graphical abstractAn efficient synthesis of sterically bulky N-heterocyclic carbenes with high percent buried volumes has been developed. The method involves three steps with approximately 40% overall yield without column chromatography. The Cu(I), Ag(I), and Au(I) chloride complexes supported by the NHC ligands were successfully synthesized and fully characterized.Figure optionsDownload full-size imageDownload as PowerPoint slide