02230nas a2200157   4500008004100000022001400041245009100055210006900146260010100215300001400316490000700330520157400337100002301911700002901934856010901963       2005                        eng d  a0888-588500aNew route for the synthesis of propylene glycols via hydroformylation of vinyl acetate0 aNew route for the synthesis of propylene glycols via hydroformyl  aPortoroz-Portorose, SloveniabAmer Chemical Soc, 1155 16th ST, NW, Washington, DC 20036 USAcDEC  a9601-96080 v443 a<p>Hydroformylation of vinyl acetate (VAM) has been studied as a key step in the alternative route for the synthesis of 1,2-propanediol (1,2-PDO) and 1,3-propanedol (1,3-PDO) using homogeneous rhodium (Rh) and cobalt (Co) complex catalysts. The feasibility of the VAM hydroformylation route has been demonstrated, and a detailed study has been reported on the key hydroformylation step using homogeneous Rh and Co catalysts. The roles of the catalyst precursors, ligands, and solvents in the activity and regioselectivity of the aldehyde products, i.e., 2-acetoxy propanal (2-ACPAL) and 3-acetoxy propanal (3-ACPAL), and the effect of reaction conditions have been investigated. With Rh-phosphine catalysts, 2-ACPAL is obtained with a selectivity of &gt; 90%, while with cobalt carbonyl catalyst, 2-ACPAL and 3-ACPAL are formed with comparable selectivities (similar to 50% each) thus substantially improving the selectivity of the linear aldehyde, a precursor for 1,3-PDO. In halogenated solvents with cobalt carbonyl catalyst, the selectivity to 3-ACPAL was found to increase still further (58%). A possible mechanism to explain the variation in regioselectivity for the Rh anal Co catalysts has been discussed. In the presence of pyridine as a ligand in the Co-catalyzed hydroformylation of VAM, the rate of reaction was found to be enhanced 4-fold. The hydrogenation of acetoxypropanal isomers using Raney-Ni catalyst followed by hydrolysis using Amberlite IR-120 resin catalyst gave quantitative conversion to the mixture of 1,2- and 1,3-PDOs (&gt; 90% yield).</p>1 aBorole, Yogesh, L.1 aChaudhari, Raghunath, V.  uhttp://library.ncl.res.in/content/new-route-synthesis-propylene-glycols-hydroformylation-vinyl-acetate-001705nas a2200229   4500008004100000022001400041245009800055210006900153260006900222300001200291490000800303520085800311653003101169653001401200653001701214100002101231700002501252700002601277700002101303700002901324856012201353       2009                        eng d  a0022-328X00aNC palladacycles in the Heck arylation of ethylene: synthesis, structure and their reactivity0 aNC palladacycles in the Heck arylation of ethylene synthesis str  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcMAR  a683-6900 v6943 a<p>Monomeric cyclopalladated complexes with NC coordination using ligands 2-phenylpyridine, 2-phenylquinoline, 8-methylquinoline have been synthesized and the structures have been determined by single crystal X-ray structure analysis. The crystal structures of monomeric palladacycles prepared using benzophenone oxime, and 2-phenylpyridine have also been determined. The use of these complexes in the Heck arylation of ethylene with 2-bromo-6-methoxynaphthalne (BMN) to give 2-vinyl-6-methoxynapthalene which is an intermediate for the synthesis of anti-inflammatory drug Naproxen has been examined and also arylation of ethylene with 3-bromo-benzophenone and 4-bromo-isobutylbenzene was investigated. These palladacycles with NC coordination show excellent catalytic activity with a TOF &gt; 4000 h (1). (C) 2008 Elsevier B.V. All rights reserved.</p>10aalpha-Aryl propionic acids10aArylation10aPalladacycle1 aAtla, Shashi, B.1 aKelkar, Ashutosh, A.1 aPuranik, Vedavati, G.1 aBensch, Wolfgang1 aChaudhari, Raghunath, V.  uhttp://library.ncl.res.in/content/nc-palladacycles-heck-arylation-ethylene-synthesis-structure-and-their-reactivity-0