Palladium(II) acetate-catalyzed Hecktype reactions have been performed from the arene 1 and alkenes (n-butyl acrylate, styrene) in acetic acid at room temperature, in the presence of a catalytic amount of benzoquinone or hydroquinone. The reactions have been made catalytic in benzoquinone [which is used to continuously oxidize the Pd(0) into to the active Pd(II) species able to activate the Ar À H bond] by the electrochemical oxidation of hydroquinone, formed in the reaction, back to benzoquinone.

A new anaerobic electrooxidative homocoupling of arylboronic acids, arylboronates and aryltrifluoroborates was developed in the presence of catalytic amounts of Pd(OAc)2 and p‐benzoquinone, which serves as a redox mediator for the oxidation of transient Pd0 to the active PdII species. The homocoupling was performed in DMF, DMF/water or in pure water. This electrochemical process avoids the use of a stoichiometric amount of chemical oxidants and subsequent formation of co‐ and by‐products.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

Primary and secondary alcohols are oxidized to aldehydes and ketones, respectively, under anaerobic conditions in DMF at 80 °C, in the presence of a base and catalytic amounts of Pd(OAc) 2 and p-benzoquinone. The latter oxidizes the transient Pd(0) formed in the catalytic cycle to Pd(II) and p-hydroquinone is re-oxidized electrochemically.

Polyphenyl derivatives Q 0700Pd (OAc)2/p-Benzoquinone-Catalyzed Anaerobic Electrooxidative Homocoupling of Arylboronic Acids, Arylboronates and Aryltrifluoroborates in DMF and/or Water. -The title electrooxidative homocoupling of arylboronic acids, -boronates or aryl trifluoroborates can also be carried out in water or aqueous DMF solution using sodium sulfate as electrolyte although best results are achieved in DMF. The method avoids the use of stoichiometric amounts of chemical oxidant and, thus, the formation of side products. -(AMATORE*, C.; CAMMOUN, C.; JUTAND, A.; Eur. J. Org. Chem. 2008, 27, 4567-4570; Dep. Chim., Ec. Norm. Super., Univ. P. et. M. Curie, F-75231 Paris, Fr.; Eng.) -Mischke 04-074