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Abstract The Cu(II)‐mediated Chan‐Lam coupling reaction offers several benefits for developing point‐of‐care detection devices on microelectrode arrays. However, achieving selectivity on borate ester‐based polymer surfaces has proven difficult due to background reactions. Fluorescence‐based studies were conducted using fluorescently labeled acetylene nucleophiles. Initial experiments revealed significant background fluorescence across the electrode array, indicating selectivity issues. Further investigation uncovered significant background reactions occurring even without copper. To address this, a strategy utilizing an arylbromide‐based polymer was developed, enhancing reaction selectivity by minimizing background non‐specific reactions. Exploration into the confinement mechanism revealed the role of acetylene in forming dimers, facilitating rapid consumption of Cu(II) reagents that escaped from the specific electrodes used. These findings offer a way to construct devices for the multiplex point‐of‐care detection of metabolites, improving performance and accuracy in diagnostic devices. 

A summary of the Faraday Discussion presented in this Special Issue and a perspective on that discussion is presented. The work highlights the specific science contributions made and the key conclusions associated with those findngs so that readers can identify papers that they would like to explore in more detail. 

Radical cation initiated cyclization reactions can be triggered by the one electron oxidation of an electron-rich olefin using either electrochemistry or visible light and a photoredox catalyst. In principle, the two methods can be used to give complimentary products with the electrolysis leading to products derived from a net two electron oxidation and the photoelectron transfer method being compatible with the formation of products from a redox neutral process. However, we are finding an increasing number of oxidative cyclization reactions that require the rapid removal of a second electron in order to form high yields of the desired product. In those cases, the electrochemical method can provide a superior approach to accessing the necessary two electron oxidation pathway. With that said, it is a combination of the two methods that provides the mechanistic insight needed to understand when a reaction has this requirement, and we are finding that the use of photoredox catalysis in combination with electrochemical methods is changing our understanding of even the most successful anodic cyclization reactions run to date. 

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. 

Abstract Paired electrochemical reactions allow the optimization of both atom and energy economy of oxidation and reduction reactions. While many paired electrochemical reactions take advantage of perfectly matched reactions at the anode and cathode, this matching of substrates is not necessary. In constant current electrolysis, the potential at both electrodes adjusts to the substrates in solution. In principle, any oxidation reaction can be paired with any reduction reaction. Various oxidation reactions conducted on the anodic side of the electrolysis were paired with the generation and use of hydrogen gas at the cathode, showing the generality of the anodic process in a paired electrolysis and how the auxiliary reaction required for the oxidation could be used to generate a substrate for a non‐electrolysis reaction. This is combined with variations on the cathodic side of the electrolysis to complete the picture and illustrate how oxidation and reduction reactions can be combined.