Electrochemistry has been used as a tool to drive chemical reactions for over two centuries. With the help of an electrode and a power source, chemists are bestowed with an imaginary reagent whose potential can be precisely dialed in. The theoretically infinite redox range renders electrochemistry capable of oxidizing or reducing some of the most tenacious compounds (e.g., F − to F 2 and Li + to Li 0). Meanwhile, a granular level of control over the electrode potential allows for the chemoselective differentiation of functional groups with minute differences in potential. These features make electrochemistry an attractive technique for the discovery of new modes of reactivity and transformations that are not readily accessible with chemical reagents alone. Furthermore, the use of an electrical current in place of chemical redox agents improves the costefficiency of chemical processes and reduces byproduct generation. Therefore, electrochemistry represents an attractive approach to meet the prevailing trends in organic synthesis and has seen increasingly broad use in the synthetic community over the past several years.

The construction of C­(sp3)–Si bonds is important in synthetic, medicinal, and materials chemistry. In this context, reactions mediated by silyl radicals have become increasingly attractive but methods for accessing these intermediates remain limited. We present a new strategy for silyl radical generation via electroreduction of readily available chlorosilanes. At highly biased potentials, electrochemistry grants access to silyl radicals through energetically uphill reductive cleavage of strong Si–Cl bonds. This strategy proved to be general in various alkene silylation reactions including disilylation, hydrosilylation, and allylic silylation under simple and transition-metal-free conditions.

We report a mild and efficient electrochemical protocol to access a variety of vicinally C–O and C–N difunctionalized compounds from simple alkenes. Detailed mechanistic studies revealed a distinct reaction pathway from those previously reported for TEMPO-mediated reactions. In this mechanism, electrochemically generated oxoammonium ion facilitates the formation of azidyl radical via a charge-transfer complex with azide, TEMPO–N3. DFT calculations together with spectroscopic characterization provided a tentative structural assignment of this charge-transfer complex. Kinetic and kinetic isotopic effect studies revealed that reversible dissociation of TEMPO–N3 into TEMPO• and azidyl precedes the addition of these radicals across the alkene in the rate-determining step. The resulting azidooxygenated product could then be easily manipulated for further synthetic elaborations. The discovery of this new reaction pathway mediated by the TEMPO+/TEMPO• redox couple may expand the scope of aminoxyl radical chemistry in synthetic contexts.

We report the development of a new aminoxyl radical catalyst, CHAMPO, for the electrochemical diazidation of alkenes. Mediated by an anodically generated charge-transfer complex in the form of CHAMPO−N 3 , radical diazidation was achieved across a broad scope of alkenes without the need for a transition metal catalyst or a chemical oxidant. Mechanistic data support a dual catalytic role for the aminoxyl serving as both a single-electron oxidant and a radical group transfer agent. The discovery of reactions mediated by organic radicals continues to provide solutions to challenging synthetic problems in traditional two-electron chemistry. 1 In this context, design and implementation of new catalytic strategies have both expanded the toolbox available for accessing new synthetic targets and transformed the fundamental understanding of reactions involving open-shell pathways. 2 For example, persistent aminoxyl radicals [e.g., (2,2,6,6tetramethylpiperidin-1-yl)oxyl (TEMPO)] have been extensively explored in catalytic oxidation reactions with both conventional chemical 3 and electrochemical techniques, 4 which has given rise to synthetically useful processes for small-molecule and polymer syntheses. Despite significant advances, we contend that the scope of TEMPO chemistry remains to be fully explored. TEMPO and related N-oxyl radicals can undergo one-electron redox processes, granting access to three discrete oxidation states. 4 This feature distinguishes these radicals from common organic compounds and likens them to many transition metal complexes. In this fashion, TEMPO has been shown to enable single-electron oxidation events in an inner-sphere manner via the formation of metastable closed-shell intermediates. 5,6 Nevertheless, the systematic use of the "metallic" character of N-oxyls in catalyst development remains meager. 7 To date, reactions catalyzed by N-oxyls are largely confined to oxidations of alcohols, 8 aldehydes, 9 amines, 10 (thio)amides, 11 and peroxyl radicals. 12 In *

In contrast to the rapid growth of synthetic electrochemistry in recent years, enantioselective catalytic methods powered by electricity remain rare. In this work, we report the development of a highly enantioselective method for the electrochemical cyanophosphinoylation of vinylarenes. A new family of serine-derived chiral bisoxazolines with ancillary coordination sites were identified as optimal ligands.