Preparation of the chiral amine salts [(η 5-C 5H 5)Ru(PPh 3)(CN tBu)(NH 2R)]PF 6, RNH 2 = α-methylbenzylamine, 1-cyclohexylethylamine, and 1-(1-naphthyl)ethylamine: X-ray single crystal structures of the diastereomeric salts ( SRuRC)- and ( RRuRC)-[(η 5-C 5H 5)Ru(PPh 3)(CN tBu){NH 2CH(Me)(Ph)}]PF 6

Abstract

Diastereomeric salts [(η 5-C 5H 5)Ru(PPh 3)(CN t Bu)(NH 2R)]PF 6 containing both a chiral metal centre and an α-chiral amine ligand have been prepared. The use of diamagnetic anisotropy in their 1H NMR spectra to distinguish the diastereomers has been supported by single crystal X-ray crystallography. The structures of the salts containing the ligands cyclohexylamine and α-methylbenzylamine (both diastereomers) have been determined at low temperature. Decomplexation of the amine ligand from purified diastereomeric salts to affect resolution of the metal centred chirality has been attempted. The chiral isonitrile ligand containing compounds [(η 5-C 5H 5)Ru(PPh 3)(CNCH(Me)Ph)(Cl)] and [(η 5-C 5H 5)Ru(PPh 3)(CNCH(Me)Ph)(NH 3)]PF 6 have been prepared from ( S)-α-methylbenzylisonitrile and the single crystal X-ray structure of both diastereomeric salts of the ammine compound has been determined.