Frithjof Hannig, G. Kehr, R. Fröhlich
Dec 1, 2005
Citations
0
Influential Citations
39
Citations
Journal
Journal of Organometallic Chemistry
Abstract
Treatment of the amino acid derivative Bz-His-OMe with excess n -propyl bromide gave the corresponding histidinium salt [Bz-His( n -propyl) 2 -OMe + Br − ]. It features a melting point of 39 °C and may serve as a useful readily available optically active ionic liquid. Its subsequent treatment with silver oxide gave the corresponding l -histidine derived chiral N-heterocyclic carbene complex [“(carbene) 2 Ag · AgBr 2 ”]. Transmetallation by treatment with Pd(CH 3 CN) 2 Cl 2 or [Rh(cod)Cl] 2 led to the formation of the respective chiral late metal imidazol-2-ylidene complexes [“(carbene) 2 PdCl 2 ”] and [“(carbene)RhCl(cod)”], respectively. Four diastereomers of the square planar palladium system were observed. Due to the additional chirality center in the l -histidine-derived “Arduengo-carbene ligand” two diastereomers of the rhodium carbene complex were formed.