Electrocatalytic reduction of CO2 into C2 products of high economic value provides a promising strategy to realize resourceful CO2 utilization. Rational design and construct dual sites to realize the CO protonation and C-C coupling to unravel their structure-performance correlation is of great significance in catalysing electrochemical CO2 reduction reactions. Herein, Cu-Cu dual sites with different site distance coordinated by halogen at the first-shell are constructed and shows a higher intramolecular electron redispersion and coordination symmetry configurations. The long-range Cu-Cu (Cu-I-Cu) dual sites show an enhanced Faraday efficiency of C2 products, up to 74.1%, and excellent stability. In addition, the linear relationships that the long-range Cu-Cu dual site is accelerated to C2H4 generation and short-range Cu-Cu (Cu-Cl-Cu) dual site is beneficial for C2H5OH formation are disclosed. In situ electrochemical attenuated total reflection surface enhanced infrared absorption spectroscopy, in situ Raman and theoretical calculations manifest that long-range Cu-Cu dual sites can weaken reaction energy barriers of CO hydrogenation and C-C coupling, as well as accelerating deoxygenation of *CH2CHO. This study uncovers the exploitation of site-distance-dependent electrochemical property to steer the CO2 reduction pathway, as well as a potential generic tactic to target C2 synthesis by constructing the desired Cu-Cu dual sites.

The electrochemical reduction of CO or CO2 into C2+ products has mostly been focused on Cu-based catalysts. Although Ag has also been predicted as a possible catalyst for the CO-to-C2+ conversion from the thermodynamic point of view, however, due to its weak CO binding strength, CO rapidly desorbs from the Ag surface rather than participates in deep reduction. In this work, we demonstrate that single-atomic Pd sites doped in Ag lattice can tune the CO adsorption behavior and promote the deep reduction of CO toward C2 products. The monodispersed Pd-Agn sites enable the CO adsorption with both Pd-atop (PdL) and Pd-Ag bridge (PdAgB) configurations, which can increase the CO coverage and reduce the C-C coupling energy barrier. Under room temperature and ambient pressure, the Pd1Ag10 alloy catalyst exhibited a total CO-to-C2 Faradaic efficiency of ~37% at ‒0.83 V, with appreciable current densities and electrochemical stability, thus featuring unconventional non-Cu electrocatalytic CO-to-C2 conversion capability.

Alkenes are fundamental functional groups which feature in various materials and bioactive molecules; however, efficient divergent strategies for their stereodefined synthesis are difficult. In this regard, numerous synthetic methodologies have been developed to construct carbon-carbon bonds with regio- and stereoselectivity, enabling the predictable and efficient synthesis of stereodefined alkenes. In fact, an appealing alternative approach for accessing challenging stereodefined alkenes molecular frameworks could involve the sequential selective activation and cross-coupling of strong bonds instead of conventional C-C bond formation. In this study, we introduce a series of programmed site- and stereoselective strategies that capitalizes on the versatile reactivity of readily accessible polymetalloid alkenes (i.e. polyborylated alkenes), through a tandem cross-coupling reaction, which is catalyzed by an organometallic Rh-complex to produce complex molecular scaffolds. By merging selective C-B and remote C-H bond functionalization, we achieve the in-situ generation of polyfunctional C(sp2)-nucleophilic intermediates. These species can be further modified by selective coupling reactions with various C-based electrophiles, enabling the formation of C(sp2)-C(sp3) bond for the generation of even more complex molecular architectures using the readily available starting polyborylated-alkenes. Mechanistic and computational studies have provided insight into the origins of the stereoselectivities and C-H activation via a 1,4-Rh migration process.

Bioactive dimeric (pre-)anthraquinones are ubiquitous in nature. Their biosynthesis via an oxidative phenol coupling (OPC) step is catalyzed by either cytochrome P450 enzymes, peroxidases, or laccases. While the biocatalysis of OPC in molds (Ascomycota) is well-known, the respective enzymes of mushroom-forming fungi (Basidiomycota) are still unknown. Here, we report on the biosynthesis of the atropisomers phlegmacin A1 and B1, unsymmetrical 7,10\'-homo-coupled dihydroanthracenones of the mushroom Cortinarius odorifer. The biosynthesis was heterologously reconstituted in the mold Aspergillus niger. We show that methylation of the dimeric (pre-)anthraquinone building block atrochrysone to its 6-O-methyl ether torosachrysone by the O-methyltransferase (CoOMT1) precedes the regioselective homo-coupling to phlegmacin, catalyzed by an unspecific peroxygenase (CoUPO1). Our results revealed an unprecedented UPO-mediated unsymmetric OPC reaction, thereby expanding the biocatalytic portfolio of OPC-type reactions beyond the commonly reported enzymes. The findings highlight the pivotal role of OPC in natural processes, demonstrating that Basidiomycota employed peroxygenases to develop the ability to selectively couple aryls, distinct and convergent to any other group of organisms.

The direct hydrogenation of greenhouse gas CO2 to higher alcohols (C2+OH) provides a new route for the production of high-value chemicals. Due to the difficulty of C-C coupling, the formation of higher alcohols is more difficult compared to that of other compounds. In this review, we summarize recent advances in the development of multifunctional catalysts, including noble metal catalysts, Co-based catalysts, Cu-based catalysts, Fe-based catalysts, and tandem catalysts for the direct hydrogenation of CO2 to higher alcohols. Possible reaction mechanisms are discussed based on the structure-activity relationship of the catalysts. The reaction-coupling strategy holds great potential to regulate the reaction network. The effects of the reaction conditions on CO2 hydrogenation are also analyzed. Finally, we discuss the challenges and potential opportunities for the further development of direct CO2 hydrogenation to higher alcohols.

Intermolecular metal-catalyzed C‒C couplings of unactivated primary alcohols or aldehydes to form ketones are catalogued. Reactions are classified on the basis of pronucleophile. Protocols involving premetalated reagents or reactants that incorporate directing groups are not covered. These methods represent an emerging alternative to classical multi-step protocols for ketone construction that exploit premetalated reagents, and/or steps devoted to redox manipulations and carboxylic acid derivatization.

A series of benzofuran and benzo[b]thiophen derivatives was synthesized via a transition-metal-free one-pot process at room temperature. This one-pot protocol enables the synthesis of compounds with high reaction efficiency, mild conditions, simple methods, and a wide-ranging substrate scope. Regioselective five-membered heterocycles were constructed in good-to-excellent yields.

Strong main-group Lewis acids such as silylium ions are known to effectively promote heterolytic C(sp3)-F bond cleavage. However, carrying out the C(sp2)-F bond transformation of vinylic C- F bonds has remained an unmet challenge. Herein, we describe our development of a new and simple strategy for vinylic C-F bond transformation of α-fluorostyrenes with silyl ketene acetals catalyzed by B(C6F5)3 under mild conditions. Our theoretical calculations revealed that a stabilized silylium ion, which is generated from silyl ketene acetals by carboboration, cleaves the C-F bond of αfluorostyrenes. A comparative study of α-chloro or bromostyrenes demonstrated that our reaction can be applied only to αfluorostyrenes because the strong silicon-fluorine affinity facilitates an intramolecular interaction of silylium ions with fluorine atom to cleave the C-F bond. A broad range of α-fluorostyrenes as well as a range of silyl ketene acetals underwent this C-F bond transformation.

Although the electroconversion of carbon dioxide (CO2 ) into ethanol is considered to be one of the most promising ways of using CO2 , the ethanol selectivity is less than 50% because of difficulties in designing an optimal catalyst that arise from the complicated pathways for the electroreduction of CO2 to ethanol. Several approaches including the fabrication of oxide-derived structures, atomic surface control, and the Cu+ /Cu interfaces have been primarily used to produce ethanol from CO2 . Here, a combined structure with Cu+ and high-facets as electrocatalysts is constructed by creating high-facets of wrinkled Cu surrounded by Cu2 O mesh patterns. Using chemical vapor deposition graphene growth procedures, the insufficiently grown graphene is used as an oxidation-masking material, and the high-facet wrinkled Cu is simultaneously generated during the graphene growth synthesis. The resulting electrocatalyst shows an ethanol selectivity of 43% at -0.8 V versus reversible hydrogen electrode, which is one of the highest ethanol selectivity values reported thus far. This is attributed to the role of Cu+ in enhancing CO binding strength, and the high-facets, which favor C-C coupling and the ethanol pathway. This method for generating the combined structure can be widely applicable not only for electrochemical catalysts but also in various fields.

Mesitylene was used as a core in seven new tritopic nitrogen containing linkers. Three of the linkers, each containing three nitrile groups, were obtained through Suzuki, Sonogashira and Heck-type coupling reactions. Next, these were converted to tetrazol-5-yl moieties by the cycloaddition of sodium azide to the nitrile functionalities. The last linker, containing three 1,2,3-triazol-4-yl moieties, was synthesized by the Huisgen cycloaddition of phenyl azide to the corresponding alkyne. The latter was obtained via a Corey-Fuchs reaction sequence from the previously reported formyl derivative. As the proof of concept for their potential in MOF design, one of the nitriles was used to build an Ag-based network.