Anodic Oxidation as an Enabling Tool for the Synthesis of Natural Products

Abstract

Electrochemistry provides a valuable toolbox for organic synthesis and offers an appealing, environmentally benign alternative to the use of stoichiometric quantities of chemical oxidants or reductants. Its potential to control current efficiency along with providing alternative reaction conditions in a classical sense makes electrochemistry a suitable method for large-scale industrial transformations as well as for laboratory applications in the synthesis of complex molecular architectures. Even though research in this field has intensified over the recent decades, many synthetic chemists still hesitate to add electroorganic reactions to their standard repertoire, and hence, the full potential of preparative organic electrochemistry has not yet been unleashed. This short review highlights the versatility of anodic transformations by summarizing their application in natural product synthesis.1 Introduction2 Shono-Type Oxidation3 C–N/N–N Bond Formation4 Aryl–Alkene/Aryl–Aryl Coupling5 Cycloadditions Triggered by Oxidation of Electron-Rich Arenes6 Spirocycles7 Miscellaneous Transformations8 Future Prospects

Electrochemically Enabled Total Syntheses of Natural Products

“…In 1959, Corey and coworkers described their seminal work in electrochemistry wherein the total synthesis of the pentacyclic triterpene pentacyclosqualene A (15) was achieved by exploiting the Kolbe electrolysis of a complex bicyclic carboxylate to construct the key intermediate 14 (Scheme 3). [64] The bicyclic ammonium carboxylate 13 was prepared in a three-step sequence starting from the diterpene sclareol (12).…”

“…Electrochemical methodology and the community of researchers involved in this exciting area of chemistry expands on a daily basis. Investigators such as Opatz and Waldvogel, [13][14][15][16][17][18]…”

“…Electrochemical methodology and the community of researchers involved in this exciting area of chemistry expands on a daily basis. Investigators such as Opatz and Waldvogel, [13–18] Baran, [19–28] Shono, [29,124,125,138,140,224] Moeller, [77,79,108,143] Little, [30–44] Lin, [45–54] and Stahl [55–62] are just a few of the researchers that have been integral to growing the available electrochemical toolset, educating the broader synthesis community, and drawing these techniques into mainstream organic synthesis. Electrochemical toolsets have been extensively reviewed in various contexts including comprehensive monographs; [5–17] this brief review highlights the use of electrochemical bond formations in the arena of natural products total synthesis with particular focus on completed works.…”

“…Investigators such as Opatz and Waldvogel, [13–18] Baran, [19–28] Shono, [29,124,125,138,140,224] Moeller, [77,79,108,143] Little, [30–44] Lin, [45–54] and Stahl [55–62] are just a few of the researchers that have been integral to growing the available electrochemical toolset, educating the broader synthesis community, and drawing these techniques into mainstream organic synthesis. Electrochemical toolsets have been extensively reviewed in various contexts including comprehensive monographs; [5–17] this brief review highlights the use of electrochemical bond formations in the arena of natural products total synthesis with particular focus on completed works. Where possible, we have endeavored to present works chronologically within different classes of natural products but for the sake of clarity, some achievements and strategies are presented by reaction type.…”