The influence of aluminium cations on electrocarboxylation processes in undivided cells with Al sacrificial anodes

CO2 as a C1-organic building block: Electrocarboxylation of aromatic ketones. A quantitative study of the effect of the concentration of substrate and of carbon dioxide on the selectivity of the process

“…Thus allowed estimations of the average value of r for each electrosynthetic condition (Tables 1 and 2). According to the quite high values of r and of the kinetic constants of the competitive reactions, at least for acetophenone and 2-chlorobenzophenone (k 12 % 254-330 s À1 [14]), the reaction layer is expected to be located very close to the electrode plane since the anion radical is not expected to live very long under our conditions. Hence, Eq.…”

“…This explains why many efforts have been devoted to the investigation of electrocarboxylation of organic halides [1,15,16] and ketones (see Eq. (1)) [2][3][4][5][6][7][8][9][10][11][12][13][14]. In particular, some of these reaction pathway have been patented in the perspective of their industrial application, particularly for the production of fine-chemicals such as anti-inflammatory drugs.…”

“…Furthermore, the use of a gaseous reactant with moderate solubility such carbon dioxide whose reduction can lead to the formation of side products such as oxalic acid and consequently to decrease the overall faradic efficiency in the target acid imposes a careful individuation of proper operative conditions. To this purpose a systematic research aimed to give a complete definition of the influence of the nature of the substrate and of operative parameters on the process is currently under development by the authors [12][13][14]. The results reported here refer to the study of the influence of various operative parameters on the selectivity of the process with a particular focus onto the effects of the concentration of the two substrates, the ketone and the carbon dioxide.…”

Electrocarboxylation and related radical coupling processes of aryl and benzyl halides in microemulsion

“…Al 3? ion generated at the anode appears to have a catalytic influence on the electrocarboxylation reactions [12]. Highly pure and moisture free DMF still remains the medium of choice for electrocarboxylation reactions [13].…”

Electrocarboxylation of aromatic ketones: Influence of operative parameters on the competition between ketyl and ring carboxylation

“…2,2-Dimethylpropiophenone, in particular, is characterised by a very high selectivity for ring carboxylated products, which constitute the main by-products, whereas electrocarboxylation of acetophenone has a quite low selectivity for all carboxylated products as a result of massive formation of 1-phenylethanol and pinacol. It is worth noting that the reaction environment may influence the distribution of the charge in the radical anion [ArC(R)O] ÅÀ and, as a consequence, the values of k c and k r and, in a final count, the competition parameter p. In particular, it is well known that radical anions generated by 1e À reduction of aromatic ketones form adducts with electrophiles such as proton donors [14][15][16][17][18] or metallic cations [19]. The charge distribution in such adducts may be significantly different from that of the free ketyl radical anion.…”