Electricity-driven asymmetric Lewis acid catalysis

Catalytic Asymmetric Electrochemical α‐Arylation of Cyclic β‐Ketocarbonyls with Anodic Benzyne Intermediates

“…Though the diastereoselectivity was low in these cases, both diasteroisomers were obtained with high enantioselectivity, indicating the arylation step is under strict catalytic control. The reaction worked well with cyclopentanone and in these cases the chiral primary amine catalyst 3 f was found to give better enantioselectivity (entries [8][9][10][11][12][13][14]. A free ketoamide could also be accommodated to afford the a-arylated adduct 4 ar (33 % yield, 84 % ee, entry 17).…”

“…[5] Anodic oxidation could be employed to in situ generate stabilized electrophilic species such as imine or iminium ion intermediates, in asymmetric aminocatalytic processes, as reported by the groups of Jørgensen [6] and Luo, [7] respectively. Recently, the groups of Meggers, [8] Guo, [9] and Lin [10] have also developed asymmetric catalysis with anodically generated free radical species. Despite these advances, the potential of asymmetric electrochemical catalysis remains largely unexplored.…”

Asymmetric Lewis Acid Catalyzed Electrochemical Alkylation

“…Indeed, groups of Jørgensen and Luo have independently established that organocatalysts can efficiently induce the enantioselectivity of asymmetric additions under electrochemical conditions. Recently, Meggers and co‐workers reported an elegant asymmetric electrochemical transformation of 2‐acyl imidazoles with silyl enol ethers involving the use of a rhodium‐bound radical intermediate . However, direct enantioselective electrosynthesis for an asymmetric radical C−H activation/radical cross‐coupling reaction remains a significant challenge …”

Asymmetric Electrochemical Catalysis

“…Recently, Meggers and co‐workers reported chiral Lewis acid catalysis in the electrochemical oxidative coupling of ketones and enol ethers. The reaction was enabled by combining Lewis acid catalysis of a chiral‐at‐metal Rh complex 19 a with electrochemical oxidation (Scheme ) . Distinctively, anodic oxidation of the nucleophilic chiral metal enolate led to a radical intermediate 19 b , which added to the enol ether to give chiral 1,4‐carbonyl compounds with good chemo‐ and enantioselectivity.…”

“…The reactionw as enabledb yc ombining Lewis acid catalysis of ac hiral-at-metal Rh complex 19 a with electrochemicalo xidation (Scheme 19). [41] Distinctively,a nodic oxidation of the nucleophilic chiral metal enolate led to ar adical intermediate 19 b,w hich added to the enol ether to give chiral 1,4-carbonyl compounds with good chemo-and enantioselectivity.T his study provides an ew strategy in pursuing asymmetric electrochemical catalysis.…”