A Novel Synthesis of 2-Aryllactic Acids via Electrocarboxylation of Methyl Aryl Ketones

Electrosyntheses of α ‐Hydroxycarboxylic Acids from Carbon Dioxide and Aromatic Ketones Using Nickel as the Cathode

“…The result was similar to that reported in the literatures. 16,18 In our experiments, it was found that the electrolysis of acetophenone in the absence of carbon dioxide only gave the product pinacol 3a (Table 1, Entry 5). Thus, the presence of CO 2 , especially CO 2 at higher pressure, could effectively suppress the radical anions resulting from the reduction of acetophenone to dimerize into pinacol 3a.…”

“…The result is in accordance with that reported in the literature. 16,18 The reason may be that increasing concentration of the substrate or water content could promote the dimerization of acetophenone radical anions. In order to better understand the effect of cathode materials, we chose Ni and Cu as working electrodes further to test the behavior of cyclic voltammetry (CV) of 1a in the presence of saturated CO 2 under the same conditions.…”

“…The results were somewhat similar to those previously reported with 2-acetyl-6-methoxynaphthalene as the substrate. 16 However, with KBr as the conducting salt, the current passed through the cell quickly became zero so that the electrolysis was unsuccessful (Table 3, Entry 6). This may be attributed to the low solubility and inferior electrical conductivity of KBr in DMF solvent.…”

“…Later, Silvestri 14 and Mcharek 15 developed a more convenient electrochemical route using an undivided cell with Al (Mg) as a sacrificial anode and compact graphite as the cathode 14 or stainless steel as the cathode 15 for the electrosynthesis. In 1995, Chan 16 applied an undivided cell with Pb cathode and Al anode in a constant current mode for the synthesis of 2-(6-methoxy-2-naphthyl)lactic acid from 6-methoxy-2-acetylnaphthalene. More recently, Lateef 17 reported that the constant current electrolysis of aromatic ketones with CO 2 in an undivided cell with Pt cathode and Mg anode could give the corresponding α-hydroxycarboxylic acids in high yields.…”

Electrocarboxylation of Alkynes with Carbon Dioxide in the Presence of Metal Salt Catalysts

“…In spite of the intrinsic thermodynamic stability of CO 2 , it can be readily reduced at the cathode 2 or indirectly activated by using transition metal complexes (Pd, Ni-, and Co). [3][4][5] In the last 50 years, many research groups have been devoted to study the fixation and conversion of CO 2 with various substrates involving alkenes, [6][7][8][9][10] alkynes, 5,[11][12][13] ketones, [14][15][16] halides, [17][18][19][20][21][22][23] epoxides [24][25] and imines. 26 The electrochemical fixation of CO 2 into the unsaturated hydrocarbons to form new carbon-carbon bonds is an interesting topic because it could afford valuable fine chemicals.…”