REACTIVITY OF CYCLOPALLADATED COMPOUNDS. VIII. SYNTHESIS OF CYCLOMETALLATED COMPOUNDS WITH AN OXYGEN AS THE DONOR ATOM. CRYSTAL AND MOLECULAR STRUCTURE OF (8-METHYLQUINOLINE-C,N)(1-METHOXYNAPHTHALENE-8-C,O)PALLADIUM(II)

Article abstract of DOI:10.1016/0022-328X(83)85076-1

Treatment of 1-methoxynaphthalene (MXNH) with n-butyllithium in a diethyl ether/n-hexane solution gives 1-methoxynaphthalene-8-lithium (MXVLi) in 30percent yield as an insoluble material.This compound reacts with PdCl2(SEt2)2 to give bis(1-methoxynaphthalene-8-C,O)palladium(II) (I) and with PtCl2(SEt2)2 to give cis- and trans-(1-methoxynaphthalene-8-C,O)(1-methoxynaphthalene-8-C)(diethylsulfide)platinum(II) (II), which are non-rigid molecules in solution.With the cyclopalladated dimers , MXNLi gives the palladobicyclic compounds: (III).An X-ray diffraction study of compound IIIa where N<*>C = 8-methylquinoline-C,N reveals the planarity of the molecule, shows that it has a cis configuration with respect to the Pd-C bonds, and confirms that the oxygen atom of MXN is bonded to palladium: Pd-O 2.236(4) Angstroem.The geometry of IIIa is maintained in solution, whereas the corresponding compounds IIIb and IIIc in which N<*>C is benzoquinoline-9-C,N and N,N-dimethyl-1-naphthylamine-8-C,N, respectively, appear to be mixtures of cis and trans isomers in solution.With PMe2Ph I and II give trans-Pd(MXN)2(PMe2Ph)2 and cis-Pt(MNX)2(PMe2Ph)2, respectively, in which the methoxynaphthalene is bound to the metals via the 8-carbon of the naphthalene ring.Only one phosphine ligand adds to compounds IIIb and IIIc with displacement of the O<*>Pd bond.One carbon monoxide ligand can be added to the platinum compound II to give Pt(MXN)2(SEt2)CO which in solution exists as two isomers in equilibrium.