Use of Sacrificial Anodes in Electrochemical Functionalization of Organic Halides

This article reviews the new possibilities in organic synthesis offered by the electroreduction of organic halides in the presence of various electrophiles using sacrificial metallic anodes. 1. Introduction 2. General Aspects of the Sacrificial Anode Process 2.1 Methodology and General Conditions 2.2. Nature of the Anode and Role of the Generated Metal Ion 2.3. Low-Valent Transition-Metal-Catalysis 3. Electrosynthesis Using the Sacrificial Anode Process 3.1. Carboxylic Acids from Organic Halides and Carbon Dioxide 3.2. Alcohols from Organic Halides and Carbonyl Compounds 3.2.1. Coupling with Acetone 3.2.2. Coupling with Other Carbonyl Compounds 3.2.3. Electrosynthesis of Alcohols Using a Nickel Catalyst 3.2.4. Conclusion 3.3. Acylation and Formylation of Organic Halides: Ketones from Anhydrides or Acid Chlorides, Aldehydes from Dimethylformamide 3.3.1. Ketones 3.3.2. Aldehydes 3.4. Homo- and Cross-Coupling of Organic Halides 3.4.1. Electrochemical Coupling of Alkyl Halides 3.4.2. Electrochemical Homocoupling of Aryl and Vinyl Halides 3.4.3. Electrochemical Cross-Coupling of α-Halo Esters with Aryl and Vinyl Halides 3.5. Formation of Carbon-Heteroatom Bond 3.5.1. Electrosynthesis of Carbon-Phosphorus Bond 3.5.2. Electrosynthesis of Carbon-Silicon Bond 3.5.3. Electrosynthesis of Trifluoromethanesulfinic Acid 3.6. Miscellaneous 3.6.1. Electrochemical Alkylation of the Carbon-Hydrogen Bond 3.6.2. Electrosynthesis of Symmetrical Ketones from Carbon Dioxide and Organic Halides 3.6.3. Electrosynthesis of Cyclic Compounds from Activated Olefins and Organic Dihalides 4. Future Prospects, Conclusions 4.1. Application of the Consumable Anode Process to the Synthesis of Complex Molecules 4.2. Industrial Developments