Alternating Copolymerization of Vinyl Acetate with Carbon Monoxide

Investigation of Steric and Electronic Factors of (Arylsulfonyl)phosphane‐Palladium Catalysts in Ethene Polymerization

“…The six-membered ring Pd1-P1-C131=C132-S1-O11-adopts a half-boat conformation, with C111 and O13 in pseudoaxial positions and C121 and O12 in pseudoequato- rial positions. This half-boat conformation has been reported for the majority of aryl sulfonate catalysts, [11,14,17,23] except for bulky aryl groups or when pyridine is replaced by DMSO. [12,15] The complete characterization of catalysts 3Pd and 4Pd is complicated by the fact that each rotamer reacts to give a separate catalyst, thus resulting in a doubling of all phosphane resonances ( Figure 3).…”

“…[15] These studies employ the catalyst [(oAr 2 PC 6 H 4 SO 3 )PdMe(L)] with Ar = o-OMePh, which corresponds to the ligand originally presented by Drent. [5] The role of the ancillary ligand L (L = pyridine, [12,16] lutidine, [17] DMSO, [15] or allyl group [11] ) on the catalytic activity has been studied in detail. However, at this time, little is known on the influence of the arylphosphane sulfonate structure.…”

Coordination Copolymerization of Polar Vinyl Monomers H2CCHX

“…It has been suggested that a weak intermittent interaction of the OMe moiety with the metal center could promote displacement of coordinated Lewis basic comonomer. [16] The synthesis and structural analysis of complexes 7, [14c, 17, 21, 25c, 26,27] which are active as single-component catalyst precursors for polymerizations, confirm the chelating k 2 -P,O coordination mode of the sulfonated phosphine. Although sulfonates bind relatively weakly to Pd II , [18] in the chelates 7 this group is not displaced even by an excess of acetonitrile or pyridine.…”

Synthesis and Applications in Catalysis of Metal Complexes with Chelating Phosphinosulfonate Ligands

“…leading to neutral transition metal complexes with unique properties. 42 16,43 Replacement of [PdMeCl(COD)] by [PdCl 2 (COD)] gave the anionic dichloropalladium [PdCl 2 (P^O)] À . 37 Ammonium sulfonates generated from the reaction of phosphinosulfonic acids 2a-H and 3a-H with tertiary aliphatic amines reacted with [PdMeCl(COD)] to afford anionic square planar palladium(II) [PdCl(P^O)Me] À complexes where the methyl ligand is located at the cis-position with respect to the phosphorus atom.…”

“…43 The proposed initial step of this polymerization is the 2,1insertion of the polar olefin into a palladium-hydride bond formed upon protonation of the palladium(0) precursor to give a five-membered chelate. The first example reported by Nozaki was the copolymerization of vinyl acetate under 6 MPa of CO pressure at 70 C in the presence of a catalytic system generated from Pd(dba) 2 and a phosphonium sulfonate.…”