Synthesis,crystal structure and reactivity of a new pentacoordinated chiral dioxomolybdenum(VI) complex

The novel tridentate chiral ligand 2,6-bis{(1R,2S,4R)-2-hydroxy-1,3,3-trimethyl-bicyclo2.2.1]hept-2-yl]}pyridine (1) was readily prepared by reaction of 2,6-dilithiopyridine with (R)-(−)-fenchone. Reaction of 1 with MoO₂(acac)₂] resulted in the formation of the new metal-oxo five-coordinated complex MoO₂(ONO)] (2) ONO = (1 – 2H)]. The reactivity of 2 has been studied and the derivatives MoS₂(ONO)] (3) and MoO(O₂)(ONO)] (4) were prepared. The compounds 1–4 have been characterised by ¹H and ¹³C{¹H} NMR, microanalysis and IR spectroscopy. Furthermore, the molecular structures of 1 and 2 have been determined by single-crystal X-ray diffraction. The behaviour of 2 as catalyst in oxotransfer and in nucleophilic substitution of propargylic alcohols reactions has been tested.