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Bi-based materials are promising catalysts for electrochemical reduction of carbon dioxide (CO2) to formate, but remain challenging in terms of activity and stability. Herein, we report the facile synthesis of Zn-doped Bi nanosheets (Zn–Bi NSs) as a highly active and robust catalyst for electrochemical reduction of CO2 to formate. Specifically, the Zn–Bi NS catalyst can be obtained using a hydrothermal method to prepare a Zn-decorated Bi2O2CO3 nanosheet followed by electrochemical reduction treatment. The as-prepared catalyst exhibits a remarkable formate faradaic efficiency of 94.6% and a high formate current density of 40.5 mA cm−2 at −1.2 V vs. reversible hydrogen electrode (RHE). In particular, the faradaic efficiency of formate remained at above 90% over a wide potential window from −0.8 to −1.2 V vs. RHE. In the H-type electrolytic cell, the Zn–Bi NS catalyst can be operated stably for 10 h at a cathode potential of −1.0 V vs. RHE with good retention of the physical phase. [ABSTRACT FROM AUTHOR]

A photoredox-catalyzed alkylarylation of activated alkenes via a radical C–C bond cleavage/Truce–Smiles rearrangement cascade is developed. The protocol features mild and redox-neutral conditions, broad substrate scope and excellent functional group compatibility, providing a facile and efficient approach to the long-chain distal keto-amides with all-carbon quaternary centers at the alpha position. [ABSTRACT FROM AUTHOR]

A metal free, visible-light driven α-C(sp3)–H gem-difluoroallylation of glycine derivatives with trifluoromethyl alkenes and 1,3-enynes is presented. This protocol features mild and redox-neutral conditions, broad substrate scope, excellent functional group compatibility, as well as high atom-efficiency, thus offering a sustainable and practical strategy to access fluorine-containing unnatural amino acids and peptides. The good scalability and excellent compatibility with biomolecules further highlight the potential utility of this protocol. [ABSTRACT FROM AUTHOR]

Herein, pre-functionalized benzyne precursors 5, 6 and 10 bearing a phosphoryl group were efficiently synthesized through a phospho-Fries rearrangement reaction on gram scales. Based on the versatile benzyne reactions ranging from nucleophilic addition and [3+2] and [4+2] cycloadditions to insertion reactions, a series of arylated organophosphorus molecules were readily achieved under mild reaction conditions. Attributed to the electron-withdrawing ability and the steric hindrance environment of phosphoryl groups, the reaction proceeded with high regioselectivity at the C1 position of 3-phosphoryl benzynes via a nucleophilic attack. Thus, this report illustrated novel phosphorus-functionalized benzynes and their regioselective formation of various poly-substituted organophosphorus arenes. [ABSTRACT FROM AUTHOR]

1,2-Dicarbofunctionalization of alkenes represents an appealing strategy for chemical bond formation in organic synthesis, which could enable the rapid construction of molecular complexity from simple and readily available starting materials by incorporating two functional groups onto a carbon–carbon double bond in one step. In this field, the dicarbofunctionalization of alkenes with different alkyl radicals in a controlled manner represents an elegant and versatile strategy to access structurally diverse functionalized alkanes, which have witnessed significant progress over the last five years. Due to the importance of alkyl radicals in organic synthesis and medicinal chemistry, this review provides a comprehensive perspective on the development of alkyl radical precursors including electrophilic precursors such as alkyl halides, alkyl peroxides, alkyl NHP esters, cycloketone oxime esters, and Katritzky pyridinium salts, and nucleophilic precursors such as alkyl acids, alkyl oxalates, alkylborates, alkylsilicates, and unactivated hydrocarbons, which generate alkyl radicals by photocatalysis or transition metal catalysis to engage in dicarbofunctionalization under oxidative reaction conditions, redox-neutral conditions, or reductive conditions. The mechanisms of these dicarbofunctionalization reactions have also been discussed in detail. [ABSTRACT FROM AUTHOR]

A mild copper-catalyzed alkylarylation of vinylarenes with cycloalkylsilyl peroxides and boronic acids is described. This three-component protocol provides a straightforward approach to the remote keto-functionalized 1,1-diarylmethane derivatives. A radical pathway initiated by C–C bond cleavage is proposed for this tandem reaction. [ABSTRACT FROM AUTHOR]

Poly(vinylidene fluoride–trifluoroethylene) (P(VDF–TrFE)) has long been known for its excellent dielectric, ferroelectric and piezoelectric performances. Besides direct copolymerization of VDF and TrFE, hydrogenation of P(VDF–CTFE) has been extensively investigated to synthesize P(VDF–TrFE) for its advantages of low-cost raw materials and better controlled composition, together with mild reaction conditions. To overcome the negative influence of metal ions from the residue of catalysts on the dielectric performance of the resultant copolymers, in the present contribution, a hydrosilane catalyst system with no metal species has been reported for the hydrogenation of P(VDF–CTFE) in a controlled radical chain transfer reaction process. C–Cl bonds in CTFE are activated by silyl radicals which are in situ formed from the catalysts. The generated P(VDF–CTFE) micro-radicals would undergo a chain transfer reaction to Si–H on hydrosilane and generate new silyl radicals. The repeated chain transfer reactions between C–Cl bonds on CTFE and Si–H bonds on hydrosilane are responsible for the quantitative hydrogenation of P(VDF–CTFE) with respect to the hydrosilane dose. The low sensitivity of hydrosilane and the radical reaction pathway allow the reaction to be conducted under rather mild conditions in most of the good solvents of P(VDF–CTFE). Thanks to the metal-free feature of the catalyst, the resultant copolymer shows significantly improved dielectric performance over that catalyzed with copper complex catalysts. Reducing P(VDF–CTFE) with hydrosilane, such as (Me3Si)3SiH, has been demonstrated to be an environmentally friendly, controllable, metal-free and mild process to synthesize a TrFE containing fluoropolymer, which has glorious prospects for the synthesis of dielectric fluoropolymers. [ABSTRACT FROM AUTHOR]

A remote OH group-directed metal-free transformation of alkynes to carbonyl compounds has been developed. Using only HOAc and EtOH solvent, this reaction elegantly converts alkynes into valuable ketones by remote hydroxyl group activation. Through comparison and isotope labeling experiments, it was confirmed that the process operates via a hydration reaction involving an acetic acid molecule, instead of a water molecule. [ABSTRACT FROM AUTHOR]

A novel and convenient metal-free nitration and cyclization of 1,6-enynes has been developed. Two C–C bonds and one C–N bond were constructed in one process in this reaction. This transformation is proven to have relatively good functional-group applicability and can be scaled up to gram quantities in satisfactory yields. According to the following experimental facts and related literature reports, a radical pathway was involved in this transformation. [ABSTRACT FROM AUTHOR]

A facile access to 4-((trifluoromethyl)thio)-2,3-dihydrofurans from unprotected homopropargylic alcohols in high regioselectivity is reported. This method is the first example of using a free hydroxy group as a nucleophile to complete a trifluoromethylthiolation/cyclization protocol with an alkyne in moderate to excellent yields. [ABSTRACT FROM AUTHOR]

A novel and convenient metal-free nitration and cyclization of 1,6-enynes has been developed. Two C-C bonds and one C-N bond were constructed in one process in this reaction. This transformation is proven to have relatively good functional-group applicability and can be scaled up to gram quantities in satisfactory yields. According to the following experimental facts and related literature reports, a radical pathway was involved in this transformation.

A facile access to 4-((trifluoromethyl)thio)-2,3-dihydrofurans from unprotected homopropargylic alcohols in high regioselectivity is reported. This method is the first example of using a free hydroxy group as a nucleophile to complete a trifluoromethylthiolation/cyclization protocol with an alkyne in moderate to excellent yields.