Palladium/Benzoquinone-Catalyzed Electrochemical Oxidation of Alcohols Under Anaerobic Conditions

Abstract

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.

Synthetic Organic Electrochemical Methods Since 2000: On the Verge of a Renaissance

“…The same group extended this system to effect palladium catalyzed electrochemical oxidation of primary and secondary alcohols to aldehydes and ketones (Figure 37B, middle). 565 The analogous chemical reaction was developed by Larock in 1998 and involved the use of molecular oxygen; the anodic protocol was operative under anaerobic conditions. 566 …”

Pd(OAc)2/p‐Benzoquinone‐Catalyzed Anaerobic Electrooxidative Homocoupling of Arylboronic Acids, Arylboronates and Aryltrifluoroborates in DMF and/or Water

“…We have developed an alternative anaerobic procedure for Pd II ‐catalyzed reactions, such as Heck‐type reactions performed from arenes10a or oxidation of alcohols to aldehydes or ketones 10b. Pd(OAc) 2 is used as a catalyst in association with a catalytic amount of p ‐benzoquinone (BQ), which serves both as a ligand (cheaper than phosphane) for Pd 0 and as an oxidant, as pioneered by Bäckvall 2,11.…”

Cooperative Electrocatalytic and Chemoselective Alcohol Oxidation by Shvo's Catalyst

“…[14] Alternatively, the popular perruthenate anion [15] or TEMPO [16] can be used as mediators for the oxidation of alcohols. Another possible mediator is benzoquinone, together with palladium acetate as a catalyst, it can be used for a Heck-type reaction between an arene and an alkene in acetic acid [17] , for an electro-oxidative homocoupling between arylboronic acids or arylboronates [18] and for the oxidation of alcohols [19] . Aldehydes and ketones could be obtained in moderate yields using this method.…”