Oxidation of dimethylplatinum(II) complexes with malonyl peroxide derivatives

Abstract

The reaction of the cyclic peroxides cyclobutane malonoyl peroxide and cyclopentane malonoyl peroxide to dimethylplatinum(II) complexes with the bidentate nitrogen donor ligand 4,4=-di-t-butyl-2,2=-bipyridine (bubpy) gave a mixture of the products of cis and trans oxidative addition, [PtMe 2 {(O 2 C) 2 C(C 3 H 6 )}(bubpy)] and [PtMe 2 {(O 2 C) 2 C(C 4 H 8 )}(bubpy)], respectively. The cis isomers exist with a chelating dicarboxylate ligand, forming a six-membered ring, while the trans isomers are thought to exist as oligomers, which may react with water or solvent to give complexes containing a monodentate dicarboxylate ligand. Equilibration of the product of cis oxidative addition, cis-[PtMe 2 {(O 2 C) 2 C(C 3 H 6 )}(bubpy)], with oxalic or phthalic acid to give equilibria with the oxalate cis-[PtMe 2 (O 4 C 2 )(bubpy)] or phthalate cis-[PtMe 2 {(O 2 C) 2 C 6 H 4 }(bubpy)] derivative, respectively, indicated the expected sequence of chelate stability oxalate > cyclobutane malonate > phthalate. Résumé: La réaction de peroxydes cycliques, le peroxyde de cyclobutane malonoyle et le peroxyde de cyclopentane malonoyle, avec des complexes de diméthylplatine (II) en présence du 4,4=-di-t-butyl-2,2=-bipyridine (bubpy), ligand bidentate donneur d'azote, a formé un mélange de produits d'addition oxydante cis et trans, le [PtMe 2 {(O 2 C) 2 C(C 3 H 6 )}(bubpy)] et le [PtMe 2 {(O 2 C) 2 C(C 4 H 8 )}(bubpy)], respectivement. Les complexes avec un ligand dicarboxylate chélatant existent sous forme d'isomères cis et forment un cycle à six atomes, tandis qu'on croit que les isomères trans existent sous forme d'oligomères qui peuvent réagir avec l'eau ou un solvant pour produire des complexes comprenant un ligand dicarboxylate monodentate. L'équilibration du produit d'addition oxydante cis, le cis-[PtMe 2 {(O 2 C) 2 C(C 3 H 6 )}(bubpy)], avec l'acide oxalique ou phtalique qui se produit pour former respectivement à l'état d'équilibre les dérivés cis-[PtMe 2 (O 4 C 2 )(bubpy)] oxalate ou cis-[PtMe 2 {(O 2 C) 2 C 6 H 4 }(bubpy)] phtalate, révèle la séquence de stabilité attendue des chélates : oxalate > malonate de cyclobutane > phthalate. [Traduit par la Rédaction]

Selective Oxygen Atom Insertion into an Aryl–Palladium Bond

“…More complex reactions involve oxidative addition followed by either reductive elimination with C–O bond formation to give 3 or 4 and water or 6 or 7 or reductive elimination with C–C bond formation to give 2c and 1,1-dimethylcyclobutabenzene (CB). Of the palladium­(IV) isomers 5a – c , the product of trans oxidative addition, 5a , is calculated to be most stable and, in related platinum­(II) chemistry, trans oxidative addition is also preferred kinetically in the polar mechanism of oxidative addition of O–O bonds . Formation of complex 3 or 4 involves overall oxygen atom insertion into the Pd–C­(sp 2 ) or Pd–C­(sp 3 ) bond, respectively, and formation of 3 is favored by 45 kJ mol –1 over 4 .…”

Lanthanide-Catalyzed Oxyfunctionalization of 1,3-Diketones, Acetoacetic Esters, And Malonates by Oxidative C–O Coupling with Malonyl Peroxides

“…Metal complexation with diacyl peroxide 2 is well documented . The first step in the C–O coupling process is nucleophilic attack by the enol form of the substrate on the La-activated malonyl peroxide to form intermediate I by charge separation.…”