Although fluorinated compounds have found widespread applications in the chemical and materials industries, general and site-specific C(sp(3))-F bond formations are still a challenging task. We report here that with the catalysis of AgNO(3), various aliphatic carboxylic acids undergo efficient decarboxylative fluorination with SELECTFLUOR(®) reagent in aqueous solution, leading to the synthesis of the corresponding alkyl fluorides in satisfactory yields under mild conditions. This radical fluorination method is not only efficient and general but also chemoselective and functional-group-compatible, thus making it highly practical in the synthesis of fluorinated molecules. A mechanism involvinig Ag(III)-mediated single electron transfer followed by fluorine atom transfer is proposed for this catalytic fluorodecarboxylation.

Recently, the development of high-performance non-platinum electrocatalysts for fuel cell applications has been gaining attention. Palladium-based nanoalloys are considered as promising candidates to substitute platinum catalysts for cathodic and anodic reactions in fuel cells. Here, we develop a facile route to synthesize dendritic palladium–copper–cobalt trimetallic nanoalloys as robust multifunctional electrocatalysts for oxygen reduction and formic acid oxidation. To the best of our knowledge, the mass activities of the dendritic Pd59Cu30Co11 nanoalloy toward oxygen reduction and formic acid oxidation are higher than those previously reported for non-platinum metal nanocatalysts. The Pd59Cu30Co11 nanoalloys also exhibit superior durability for oxygen reduction and formic acid oxidation as well as good antimethanol/ethanol interference ability compared to a commercial platinum/carbon catalyst. The high performance of the dendritic Pd59Cu30Co11 nanoalloys is attributed to a combination of effects, including defects, a synergistic effect, change of d-band center of palladium, and surface strain.

We report herein a mild and catalytic intramolecular aminofluorination of unactivated alkenes. Thus, with the catalysis of AgNO3, the reactions of various N-arylpent-4-enamides with Selectfluor reagent in CH2Cl2/H2O led to the efficient synthesis of 5-fluoromethyl-substituted γ-lactams. A mechanism involving silver-catalyzed oxidative generation of amidyl radicals and silver-assisted fluorine atom transfer was proposed.

C(sp(3))-C(sp) bond formations are of immense interest in chemistry and material sciences. We report herein a convenient, radical-mediated and catalytic method for C(sp(3))-C(sp) cross-coupling. Thus, with AgNO(3) as the catalyst and K(2)S(2)O(8) as the oxidant, various aliphatic carboxylic acids underwent decarboxylative alkynylation with commercially available ethynylbenziodoxolones in aqueous solution under mild conditions. This site-specific alkynylation is not only general and efficient but also functional group compatible. In addition, it exhibits remarkable chemo- and stereoselectivity.

We report herein a mild and catalytic phosphonofluorination of unactivated alkenes. With catalysis by AgNO3, the condensation of various unactivated alkenes with diethyl phosphite and Selectfluor reagent in CH2Cl2/H2O/HOAc at 40 °C led to the efficient synthesis of β-fluorinated alkylphosphonates with good stereoselectivity and wide functional group compatibility. A mechanism involving silver-catalyzed oxidative generation of phosphonyl radicals and silver-assisted fluorine atom transfer is proposed.

The copper-mediated trifluoromethylation of alkyl radicals is described. The combination of EtSiH and KSO initiates the radical reactions of alkyl bromides or iodides with BPyCu(CF) (BPy = 2,2'-bipyridine) in aqueous acetone at room temperature to afford the corresponding trifluoromethylation products in good yield. The protocol is applicable to various primary and secondary alkyl halides and exhibits wide functional group compatibility. A mechanism involving trifluoromethyl group transfer from Cu(II)-CF intermediates to alkyl radicals is proposed.

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Decarboxylative halogenation of carboxylic acids, the Hunsdiecker reaction, is one of the fundamental functional group transformations in organic chemistry. As the initial method requires the preparations of strictly anhydrous silver carboxylates, several modifications have been developed to simplify the procedures. However, these methods suffer from the use of highly toxic reagents, harsh reaction conditions, or limited scope of application. In addition, none is catalytic for aliphatic carboxylic acids. In this Article, we report the first catalytic Hunsdiecker reaction of aliphatic carboxylic acids. Thus, with the catalysis of Ag(Phen)(2)OTf, the reactions of carboxylic acids with t-butyl hypochlorite afforded the corresponding chlorodecarboxylation products in high yields under mild conditions. This method is not only efficient and general, but also chemoselective. Moreover, it exhibits remarkable functional group compatibility, making it of more practical value in organic synthesis. The mechanism of single electron transfer followed by chlorine atom transfer is proposed for the catalytic chlorodecarboxylation.