C, A dipalladium II

To a suspension of the cyclopalladated compound (12.95 g, 47 mmol) in acetone (300 mL) is added an excess of LiCl (6.77 g, 150 mmol). This mixture is heated with vigorous stirring until the precipitate has dissolved. It is likely that with an excess of LiCl the salt Li[PdC6H4CH2N(CH3)2Cl2] is formed, which is stable only in acetone in the absence of water. Addition of water to this solution affords immediately the chloro-bridged dimer. The yellow solution is then quickly filtered over a short column of Celite (3 cm) to retain the finely divided metallic palladium and the column washed with 50 mL of acetone. The solution thus obtained is poured into a beaker containing 400 mL of water affording a yellow precipitate. The more quickly this operation is done the better the yield of the reaction the overall time of this purification should not 

The air stable, lemon yellow crystalline compound is slightly soluble in chloroform, acetone, or tetrahydrofuran (THF). Its IR spectrum (KBr pellet) shows typical absorptions for an ortho disubstituted phenyl ring at 745 and 736cm 1. Its HNMR spectrum [CDC13, 200MHz] shows three singlets d = 3.92 (CH2), 2.855 and 2.838ppm, (N(CH3)2. 

It is a useful starting material for organic synthesis. It reacts readily with alkenes (such as methyl vinyl ketone, styrene, methyl acrylate, etc.), carbon monoxyde, isocyanides, and acyl chlorides to afford good yields of organic products by selective formation of carbon-carbon bonds.8 

8-Methylquinoline (2.86 g, 20 mmol) is added to a stirred suspension of palladium acetate (4.48 g, 20 mmol) in dichloromethane (150 mL) in a 250-mL beaker. The mixture is stirred for 4 h at room temperature. The brown solution is then filtered and the solution is dried in vacuo. The oily residue thus obtained is washed with diethyl ether (10 mL) and then with pentane (4 x 50 mL) to give 5.9 g (96%) of the acetato-bridged dimer as an orange powder. It can be crystallized from a chloroform-diethyl ether solution as deep yellow crystals. 

To a solution of this product (4.1 g, 13.3 mmol) in 500 mL of acetone is added an excess of lithium chloride (2.8 g, 66 mmol). The mixture is gently heated with stirring (it is generally not necessary to boil the acetone) until the yellow precipitate of the chloro-bridged dimer, which is formed at the beginning of the reaction, is redissolved. The mixture is filtered to remove the 

DI-p-CHLORO-BlS[ (2-DIMETH YLAMlNO)lVIETHYL]PHENYL-C, iV)DIPALLADIUM(II) 

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Herrmann WA, Brossmer C, Reisinger CP, Riermaier T, Ofele K, Beller M (1997) Coordination chemistry and mechanisms of metal-catalyzed C-C coupling reactions. Part 10. Palladacycles efficient new catalysts for the Heck vinylation of aryl halides. Chem Eur J 3 1357-1364 Iyer S, Jayanthi A (2001) Acetylferrocenyloxime palladacycle-catalyzed Heck reactions. Tetrahedron Lett 42 7877-7878 Iyer S, Ramesh C (2000) Aryl-Pd covalently bonded palladacycles, novel amino and oxime catalysts di- x-chlorobis(benzaldehydeoxime-6-C,AT)dipalla-dium(II), di- x-chlorobis(dimethylbenzylamine-6-C,A)dipalladium(II) for the Heck reaction. Tetrahedron Lett 41 8981-8984 Jeffery T (1984) Palladium-catalysed vinylation of organic halides under solid-liquid phase transfer conditions. J Chem Soc Chem Commun 1287-1289 (b) idem,... 

Iyer, S. and Ramesh, C. (2000) Aryl-Pd covalently bonded palladacycles, novel amino and oxime catalysts di-/x-chlorobis(benzaldehydeoxime-6-CJV)dipalladium(II), di-/r-chlorobis(dimethylbenzylamine-6-C,A)dipalladium(II) for the Heck reaction. Tetrahedron Lett., 41, 8981-4. 

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