The integration of renewable energy sources into the electric grid requires low-cost storage systems that mediate variable and intermittent flux associated with most renewables. Nonaqueous redox-flow batteries have emerged as a promising technology for grid-scale applications. Because cost system scales mass, electroactive materials must low equivalent weight (ideally 150 g/(mol·e−) or less), function molecular supporting electrolytes such LiBF4. However, soluble anolyte undergo reversible...

Catalytic hydroarylation of alkenes is a desirable process because it can occur under neutral conditions with regioselectivity complementary to that acid-catalyzed reactions and stereoselectivity derived from the catalyst. We report an intermolecular asymmetric addition C-H bonds indoles, thiophenes, pyrroles, furans bicycloalkenes in high yield enantiomeric excess. These heteroarene alkylations ortho heteroatom. This selectivity observed even unprotected which typically undergo alkylation...

The deployment of nonaqueous redox flow batteries for grid-scale energy storage has been impeded by a lack electrolytes that undergo events at as low (anolyte) or high (catholyte) potentials possible while exhibiting the stability and cycling lifetimes necessary battery device. Herein, we report new approach to electrolyte design uses physical organic tools predictive targeting possess this combination properties. We apply identification pyridinium-based anolyte undergoes 1e– electrochemical...

Cross-electrophile coupling (XEC) reactions of aryl and alkyl electrophiles are appealing but limited to specific substrate classes. Here, we report electroreductive XEC previously incompatible including tertiary bromides, chlorides, aryl/vinyl triflates. Reactions rely on the merger an electrochemically active complex that selectively reacts with bromides through 1e

Nonaqueous redox flow batteries (NRFBs) represent an attractive technology for energy storage from intermittent renewable sources. In these batteries, electrical is stored in and extracted electrolyte solutions of redox-active molecules (termed catholytes anolytes) that are passed through electrochemical cell. To avoid battery self-discharge, the anolyte catholyte must be separated by a membrane This prevents crossover active molecules, while simultaneously allowing facile transport...

The addition of an N-H bond to olefin is the most direct route for synthesis alkylamines. Currently, intermolecular hydroamination limited reactions a narrow range reagents containing bonds or activated alkenes, and all examples additions unactivated alkenes require large excesses alkene. We report indoles with olefins. occur as few 1.5 equiv form N-alkylindoles exclusively in good yield. Characterizations catalyst resting state, kinetic data, labeling studies, computational data imply that...

The intermolecular addition of N-H bonds to unactivated alkenes remains a challenging, but desirable, strategy for the synthesis N-alkylamines. We report amination α-olefins and bicycloalkenes with arylamides sulfonamides generate synthetically useful protected amine products in high yield. Mechanistic studies on this rare catalytic reaction revealed resting state that is product bond oxidative coordination amide. Rapid, reversible dissociation amide precedes alkene, an intramolecular,...

Cross-electrophile coupling (XEC) of alkyl and aryl halides promoted by electrochemistry represents an attractive alternative to conventional methods that require stoichiometric quantities high-energy reductants. Most importantly, electroreduction can readily exceed the reducing potentials chemical reductants activate catalysts with improved reactivities selectivities over systems. This work details mechanistically-driven development electrochemical methodology for XEC utilizes redox-active...

Abstract Intermittent energy sources, including solar and wind, require scalable, low‐cost, multi‐hour storage solutions in order to be effectively incorporated into the grid. All‐Organic non‐aqueous redox‐flow batteries offer a solution, but suffer from rapid capacity fade low Coulombic efficiency due high permeability of redox‐active species across battery's membrane. Here we show that active‐species crossover is arrested by scaling membrane's pore size molecular dimensions turn increasing...

A series of small redox-active organics based on cyclopropenium salts are identified as promising nonaqueous catholytes. Synthetic modification provides access to highly soluble catholytes at all redox states (>0.7 m) and that undergo >200 charge–discharge cycles high potentials (>0.8 V vs Fc/Fc+). The oxidized catholyte is isolable stable concentration for days without degradation.

The development of nonaqueous redox flow batteries (NRFBs) has been impeded by a lack electroactive compounds (anolytes and catholytes) with the necessary combination (1) potentials that exceed potential limits water, (2) high solubility in media, (3) stability toward electrochemical cycling. In addition, ideal materials would maintain all three these properties over multiple electron transfer events, thereby providing proportional increase storage capacity. This paper describes...

The direct and scalable electroreduction of triphenylphosphine oxide (TPPO)—the stoichiometric byproduct some the most common synthetic organic reactions—to (TPP) remains an unmet challenge that would dramatically reduce cost waste associated with performing desirable reactions are mediated by TPP on a large scale. This report details electrochemical methodology for single-step reduction TPPO to using aluminum anode in combination supporting electrolyte continuously regenerates Lewis acid...

The oxidative coupling of arenes and alkenes is an attractive strategy for the synthesis vinylarenes, but reactions with unactivated have typically occurred in low yield. We report Ir-catalyzed furans olefins to generate branched vinylfuran products high yields selectivities a second alkene as hydrogen acceptor. Detailed mechanistic experiments revealed catalyst decomposition pathways that were alleviated by judicious selection reaction conditions application new ligands.

Simple copper salts serve as catalysts to effect C–X bond-forming reactions in some of the most utilized transformations synthesis, including oxidative coupling aryl boronic acids and amines. However, these Chan–Lam have historically relied on chemical oxidants that limit their applicability beyond small-scale synthesis. Despite success replacing strong with electrochemistry for a variety metal-catalyzed processes, electrooxidative ligandless are plagued by slow electron-transfer kinetics,...

Electroreductive cross-electrophile coupling (eXEC) represents an attractive approach for the direct C-C of two electrophiles but generally suffers from limited scope compared to reactions with chemical reductants. This work demonstrates that mediator-assisted electrocatalysis is a general strategy enhancement eXEC reactions. While catalyzed by variety widely available ligand-nickel complexes are low yielding when applied reductive couplings challenging substrates, same generate products in...

We report the systematic development of an electrooxidative methodology that translates stoichiometric C–H fluorination reactivity isolable CuIII fluoride complex into a catalytic process. The critical challenges electrocatalysis with highly reactive species are addressed by judicious selection electrolyte, F− source, and sacrificial electron acceptor. Catalyst-controlled occurs preference for hydridic bonds high bond-dissociation energies over weaker but less bonds. selectivity is driven...

Recent efforts have led to the design of new anolytes for nonaqueous flow batteries that exhibit reversible redox couples at low potentials. However, these molecules generally cycle through just a single electron-transfer event, which limits overall energy density resulting on account undesirably high equivalent weight (i.e., ratio anolyte/supporting electrolyte molecular electrons transferred). In addition, require expensive alkylammonium salts as supporting electrolytes stable cycling,...

Despite significant efforts to replace Pd-based catalysts with those of Ni, the Ni-catalyzed Mizoroki–Heck coupling aryl halides and alkenes remains challenging. This work details development a reaction broad range that utilizes electrochemistry as means promote under mild conditions. Stoichiometric studies implicate low-valent Ni complexes key intermediates in route rapid reactions even unactivated alkenes. As such, is employed readily provide reducing potentials necessary access these...

While the electrooxidative activation of carboxylic acids is an attractive synthetic methodology, resulting transformations are generally limited to either homocoupling or further oxidation followed by solvent capture. These reactions require extensive electrolysis at high potentials, which ultimately renders methodology incompatible with metal catalysts that could possibly provide new and complementary product distributions. This work establishes a proof-of-concept for rare...

An electrochemical, nickel-catalyzed reductive coupling of alkylpyridinium salts and aryl halides is reported. High-throughput experimentation (HTE) was employed for rapid reaction optimization evaluation a broad scope pharmaceutically relevant structurally diverse halides, including complex drug-like substrates. In addition, the transformation compatible with both primary secondary distinct conditions. Mechanistic insights were critical to enhance efficiency using salts. Systematic...

Metal-catalyzed addition of an O–H bond to alkene is a desirable process because it allows for rapid access ethers from abundant starting materials without the formation waste, rearrangements, and with possibility control stereoselectivity. We report intermolecular, metal-catalyzed phenols unactivated α-olefins. Mechanistic studies this rare catalytic reaction revealed dynamic mixture resting states that undergo oxidative subsequent olefin insertion form ether products.

Aqueous redox flow batteries (RFBs) can serve as inexpensive grid-scale energy storage devices. A key challenge for developing these systems is identifying materials that undergo reversible events at potentials near the voltaic limits of aqueous media. This work details development a benzoylpyridinium-based anolyte this application. combination electrochemical and spectroscopic studies guided selection supporting electrolyte to mitigate anolyte-catalyzed proton reduction low potentials....