Electrogenerated Acids and Bases

Abstract

The sections in this article are Electrogenerated Acids General Concepts Influence of the Solvent‐electrolyte System In situ Versus Ex situ Formation of the EGA Comparison of EGAs with Conventional Acids Charge‐consuming Reactions EGA Catalyzed Follow‐up Reaction of the Product of Anodic Oxidation EGA Induced Conversion of Substrate Acid Catalyzed Reactions Ring Opening of Epoxides Reaction of Acetals, Ketones, and Aldehydes with Nucleophiles 1,4‐Addition to Enones Functional Group Protection Electrophilic Aromatic Substitution Cyclizations Diels–Alder Reactions Electrogenerated Bases General Concepts In situ Versus Ex situ Formation of the EGB Kinetic Versus Thermodynamic Basicity Efficiency of the Proton Transfer Reaction Comparison of EGBs with Conventional Bases Nitrogen Bases Azo Compounds and Nitrogen Heteroaromatics as Probases Amides as Probases Oxygen Bases Dioxygen as Probase Phenols as Probases Carbonyl Compounds as Probases Carbon Bases Activated Alkenes as Probases Carbanions as EGBs Other Electrogenerated Carbon Bases Reactions Consuming Stoichiometric Amounts of Base Wittig Reactions Addition to Aldehydes and Ketones Alkylation of Activated Methylene Compounds Cyanomethylation Carboxylation Cyclizations Oxidative Conversions Condensations Miscellaneous Reactions Base‐Catalyzed Reactions Michael Additions Reactions Involving Aldehydes and Ketones

Electron Transfer Initiated Reactions: Bond Formation and Bond Dissociation

“…103,108,125 Electrochemically initiated reactions have been widely investigated since they can be used as a source of electrogenerated acids. 126 Elimination of a proton has also been used in the anodic substitution of C-H bonds. 4 Alkyl aromatic compounds [127][128][129][130][131][132][133][134][135][136] (Scheme 4) have been the most widely investigated reactants since the oxidative bond dissociation is an efficient route to their side chain oxidation leading principally to the corresponding aromatic aldehydes.…”

“…102,[140][141][142] An interesting example of a C-C bond cleavage under oxidative conditions is the decarboxylation of radical cations (Scheme 5). [125][126][127]143 Kinetic studies illustrating the effect of neighboring groups, 144 the redox properties of the parent reactant 145 and the nature of the medium 146,147 have all been reported.…”

Electrogenerated Cationic Reactive Intermediates: The Pool Method and Further Advances

“…Although electrogenerated acids can be categorized as pools of electrogenerated cationic species, we do not consider them in this article, because they have not yet been fully characterized and the mechanism of their generation is not clear at present. 38,39 3. CARBOCATIONS Carbenium and onium ions are important reactive species in organic chemistry and are widely used as intermediates in organic synthesis.…”

“…In the following sections, we discuss the electrooxidative generation, accumulation, and reactions of cationic reactive intermediates including carbon, nitrogen, phosphorus, sulfur, halogen, and some other cationic species that play important roles in organic synthesis. Although electrogenerated acids can be categorized as pools of electrogenerated cationic species, we do not consider them in this article, because they have not yet been fully characterized and the mechanism of their generation is not clear at present. , …”

Overcoming the limitations of Kolbe coupling with waveform-controlled electrosynthesis

“…In general, dc electrolysis creates local areas of enhanced acidity surrounding the anode at the microscopic level (regardless of stirring rate) through oxidation of solvent, water, or the substrate itself, known as electrogenerated acid (52). Counterintuitive to the reaction solution being partially neutralized, this phenomenon leads to protonation of carboxylate at the anode.…”