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  1. Abstract

    C−C linked glutarimide‐containing structures with direct utility in the preparation of cereblon‐based degraders (PROTACs, CELMoDs) can be assessed in a single step from inexpensive, commercial α‐bromoglutarimide through a unique Brønsted‐acid assisted Ni‐electrocatalytic approach. The reaction tolerates a broad array of functional groups that are historically problematic and can be applied to the simplified synthesis of dozens of known compounds that have only been procured through laborious, wasteful, multi‐step sequences. The reaction is scalable in both batch and flow and features a trivial procedure wherein the most time‐consuming aspect of reaction setup is weighing out the starting materials.

     
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    Free, publicly-accessible full text available March 7, 2025
  2. Abstract

    Over the last fifty years, the use of nickel catalysts for facilitating organic transformations has skyrocketed. Nickel(0) sources act as useful precatalysts because they can enter a catalytic cycle through ligand exchange, without needing to undergo additional elementary steps. However, most Ni(0) precatalysts are synthesized with stoichiometric aluminum–hydride reductants, pyrophoric reagents that are not atom‐economical and must be used at cryogenic temperatures. Here, we demonstrate that Ni(II) salts can be reduced on preparative scale using electrolysis to yield a variety of Ni(0) and Ni(II) complexes that are widely used as precatalysts in organic synthesis, including bis(1,5‐cyclooctadiene)nickel(0) [Ni(COD)2]. This method overcomes the reproducibility issues of previously reported methods by standardizing the procedure, such that it can be performed anywhere in a robust manner. It can be transitioned to large scale through an electrochemical recirculating flow process and extended to an in situ reduction protocol to generate catalytic amounts of Ni(0) for organic transformations. We anticipate that this work will accelerate adoption of preparative electrochemistry for the synthesis of low‐valent organometallic complexes in academia and industry.

     
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  3. Abstract

    Bioelectrocatalytic synthesis is the conversion of electrical energy into value‐added products using biocatalysts. These methods merge the specificity and selectivity of biocatalysis and energy‐related electrocatalysis to address challenges in the sustainable synthesis of pharmaceuticals, commodity chemicals, fuels, feedstocks and fertilizers. However, the specialized experimental setups and domain knowledge for bioelectrocatalysis pose a significant barrier to adoption. This review introduces key concepts of bioelectrosynthetic systems. We provide a tutorial on the methods of biocatalyst utilization, the setup of bioelectrosynthetic cells, and the analytical methods for assessing bioelectrocatalysts. Key applications of bioelectrosynthesis in ammonia production and small‐molecule synthesis are outlined for both enzymatic and microbial systems. This review serves as a necessary introduction and resource for the non‐specialist interested in bioelectrosynthetic research.

     
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  4. Abstract

    A mild, scalable (kg) metal‐free electrochemical decarboxylation of alkyl carboxylic acids to olefins is disclosed. Numerous applications are presented wherein this transformation can simplify alkene synthesis and provide alternative synthetic access to valuable olefins from simple carboxylic acid feedstocks. This robust method relies on alternating polarity to maintain the quality of the electrode surface and local pH, providing a deeper understanding of the Hofer‐Moest process with unprecedented chemoselectivity.

     
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  5. Abstract

    There is a pressing need, particularly in the field of drug discovery, for general methods that will enable direct coupling of tertiary alkyl fragments to (hetero)aryl halides. Herein a uniquely powerful and simple set of conditions for achieving this transformation with unparalleled generality and chemoselectivity is disclosed. This new protocol is placed in context with other recently reported methods, applied to simplify the routes of known bioactive building blocks molecules, and scaled up in both batch and flow. The role of pyridine additive as well as the mechanism of this reaction are interrogated through Cyclic Voltammetry studies, titration experiments, control reactions with Ni(0) and Ni(II)‐complexes, and ligand optimization data. Those studies indicate that the formation of a BINAPNi(0) is minimized and the formation of an active pyridine‐stabilized Ni(I) species is sustained during the reaction. Our preliminary mechanistic studies ruled out the involvement of Ni(0) species in this electrochemical cross‐coupling, which is mediated by Ni(I) species via a Ni(I)‐Ni(II)‐Ni(III)‐Ni(I) catalytic cycle.

     
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  6. Abstract

    Samarium diiodide (SmI2) is widely used as a strong one‐electron reducing agent and is often employed to form C−C bonds in complex systems. Despite their utility, SmI2and related salts suffer from several drawbacks that render the use of Sm reducing agents in large‐scale synthesis impractical. Here, we report factors influencing the electrochemical reduction of Sm(III) to Sm(II), towards the goal of electrocatalytic Sm(III) reduction. We probe the effect of supporting electrolyte, electrode material, and Sm precursor on Sm(II)/(III) redox and on the reducing power of the Sm species. We find that the coordination strength of the counteranion of the Sm salt affects the reversibility and redox potential of the Sm(II)/(III) couple and establish that the counteranion primarily determines the reducibility of Sm(III). Electrochemically generated SmI2performs similarly to commercial SmI2solutions in a proof‐of‐concept reaction. The results will provide fundamental insight to facilitate the development of Sm‐electrocatalytic reactions.

     
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  7. Abstract

    Simple access to aryl sulfinates from aryl iodides and bromides is reported using an inexpensive Ni‐electrocatalytic protocol. The reaction exhibits a broad scope, uses stock solution of simple SO2as sulfur source, and can be scaled up in batch and recycle flow settings. The limitations of this reaction are clearly shown and put into context by benchmarking with state‐of‐the‐art Pd‐based methods.

     
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  8. Abstract

    Electrochemistry offers a variety of novel means by which selectivity can be introduced into synthetic organic transformations. In the work reported, it is shown how methods used to confine chemical reactions to specific sites on a microelectrode array can also be used to confine a preparative reaction to the surface of an electrode inserted into a bulk reaction solution. In so doing, the surface of a modified electrode can be used to introduce new selectivity into a preparative reaction that is not observed in the absence of either the modified electrode surface or the effort to confine the reaction to that surface. The observed selectivity can be optimized in the same way that confinement is optimized on an array and is dependent on the nature of the functionalized surface.

     
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  9. Abstract

    The formation of aryl‐alkyl ether bonds through cross coupling of alcohols with aryl halides represents a useful strategic departure from classical SN2 methods. Numerous tactics relying on Pd‐, Cu‐, and Ni‐based catalytic systems have emerged over the past several years. Herein we disclose a Ni‐catalyzed electrochemically driven protocol to achieve this useful transformation with a broad substrate scope in an operationally simple way. This electrochemical method does not require strong base, exogenous expensive transition metal catalysts (e.g., Ir, Ru), and can easily be scaled up in either a batch or flow setting. Interestingly, e‐etherification exhibits an enhanced substrate scope over the mechanistically related photochemical variant as it tolerates tertiary amine functional groups in the alcohol nucleophile.

     
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  10. Abstract

    The development of electrochemical catalytic conversion of 5‐hydroxymethylfurfural (HMF) has recently gained attention as a potentially scalable approach for both oxidation and reduction processes yielding value‐added products. While the possibility of electrocatalytic HMF transformations has been demonstrated, this growing research area is in its initial stages. Additionally, its practical applications remain limited due to low catalytic activity and product selectivity. Understanding the catalytic processes and design of electrocatalysts are important in achieving a selective and complete conversion into the desired highly valuable products. In this Minireview, an overview of the most recent status, advances, and challenges of oxidation and reduction processes of HMF was provided. Discussion and summary of voltammetric studies and important reaction factors (e. g., catalyst type, electrode material) were included. Finally, biocatalysts (e. g., enzymes, whole cells) were introduced for HMF modification, and future opportunities to combine biocatalysts with electrochemical methods for the production of high‐value chemicals from HMF were discussed.

     
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