Synthesis and coordination of the new chiral tridentate O,N,O ligand 2,6-[bis[(1S,2S,5R)-(-)-menthyl]pyridine to molybdenum(VI) and vanadium(V) oxo complexes:: Crystal structures of [(2,6-bis{(-)-menthyl} pyridine)MoO2] and [(2,6-bis{(-)-menthyl}pyridine)VO]2(μ-O)

The novel tridentate chiral ligand 2,6-bis{(-)-menthyl)pyridine (1), was readily prepared from the reaction of 2,6-dilithiopyridine with (-)-menthone. Reaction of 1 with VO(OiPr)(3) and [MoO2(acac)(2)] resulted in the formation of the new metal-ore complexes [VO(ONO)](2)(mu-O) (2) and [MoO2(ONO)] (3) [ONO = (1 - 2 H)]. Both metal-ore compounds 2 and 3 have demonstrated the ability to catalyze the asymmetric oxidation of prochiral olefins with tBuOOH as the oxidant. The compounds 1-3 have been fully characterized by H-1, C-13 and V-51 (where appropriate) NMR spectroscopy, mass spectrometry, microanalysis and IR spectroscopy. Furthermore, the molecular structures of 2 and 3 have been determined by single-crystal X-ray diffraction.