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Nitrogen (N2) fixation by nature, which is a crucial process for the supply of bio-available forms of nitrogen, is performed by nitrogenase. This enzyme uses a unique transition-metal–sulfur–carbon cluster as its active-site co-factor ([(R-homocitrate)MoFe7S9C], FeMoco)1,2, and the sulfur-surrounded iron (Fe) atoms have been postulated to capture and reduce N2 (refs. 3–6). Although there are a few examples of synthetic counterparts of the FeMoco, metal–sulfur cluster, which have shown binding of N2 (refs. 7–9), the reduction of N2 by any synthetic metal–sulfur cluster or by the extracted form of FeMoco10 has remained elusive, despite nearly 50 years of research. Here we show that the Fe atoms in our synthetic [Mo3S4Fe] cubes11,12 can capture a N2 molecule and catalyse N2 silylation to form N(SiMe3)3 under treatment with excess sodium and trimethylsilyl chloride. These results exemplify the catalytic silylation of N2 by a synthetic metal–sulfur cluster and demonstrate the N2-reduction capability of Fe atoms in a sulfur-rich environment, which is reminiscent of the ability of FeMoco to bind and activate N2.Iron atoms in a synthetic metal–sulfur cluster can capture nitrogen and catalyse its silylation, demonstrating successful nitrogen reduction by iron atoms in a sulfur-rich environment. [ABSTRACT FROM AUTHOR]

Earth‐abundant metal‐catalyzed oxidative conversion of ammonia into dinitrogen is a promising process to utilize ammonia as a transportation fuel. Herein, we report the manganese‐catalyzed ammonia oxidation under chemical or electrochemical conditions using a manganese complex bearing (1S,2S)‐N,N′‐bis(3,5‐di‐tert‐butylsalicylidene)‐1,2‐cyclohexanediamine. Under chemical conditions using oxidant, up to 17.1 equivalents of N2 per catalyst are generated. Also, mechanistic studies by stoichiometric reactions reveal that a nucleophilic attack of ammonia on manganese nitrogenous species occurs to form a nitrogen–nitrogen bond leading to dinitrogen. Moreover, we conduct density functional theory (DFT) calculations to confirm the plausible reaction mechanism. In addition, this reaction system is applicable under electrochemical conditions. The catalytic reaction proceeds with 96 % faradaic efficiency (FE) in bulk electrolysis to give up to 6.56 equivalents of N2 per catalyst. [ABSTRACT FROM AUTHOR]

Cover Feature: Photoredox- and Nickel-Catalyzed Hydroalkylation of Alkynes with 4-Alkyl-1,4-dihydropyridines: Ligand-Controlled Regioselectivity (Chem. Eur. J. 36/2022) Keywords: alkylation; homogeneous catalysis; ligand effects; photocatalysis; regioselectivity EN alkylation homogeneous catalysis ligand effects photocatalysis regioselectivity 1 1 1 06/29/22 20220627 NES 220627 B A carp (alkyne) swimming up a waterfall b falling from a legendary mountain (energy gap that is hard to jump without photoexcitation) accepts a pearl (alkyl radical) prepared by an oyster (Ir photoredox catalyst) under sunlight irradiation and becomes a dragon with a pearl in its mouth (Markovnikov-type product) or in its claws ( I anti i -Markovnikov-type product) after going through different I longmen i or dragon gates (different Ni catalysts). Alkylation, homogeneous catalysis, ligand effects, photocatalysis, regioselectivity. [Extracted from the article]

Front Cover: Ruthenium- and Copper-Catalyzed Propargylic Substitution Reactions of Propargylic Alcohol Derivatives with Hydrazones (Chem. Eur. J. 63/2021) Copper, DFT calculations, hydrazones, propargylic substitution reactions, ruthenium Keywords: copper; DFT calculations; hydrazones; propargylic substitution reactions; ruthenium EN copper DFT calculations hydrazones propargylic substitution reactions ruthenium 15558 15558 1 11/16/21 20211111 NES 211111 B Origami is a traditional paper-folding art b that enables different structures, such as zabuton (cushion) and shuriken (concealed throwing star), to be constructed from unit papers. [Extracted from the article]

Keywords: ammonia oxidation; dinitrogen; electrochemical oxidation; heterogeneous catalysis; transition metal complexes EN ammonia oxidation dinitrogen electrochemical oxidation heterogeneous catalysis transition metal complexes 1498 1498 1 11/30/21 20211101 NES 211101 B The Cover Feature shows b manganese-catalyzed ammonia oxidation, which is currently attracting attention because of its potential applications to direct ammonia fuel cells. Ammonia oxidation, dinitrogen, electrochemical oxidation, heterogeneous catalysis, transition metal complexes Furthermore, mechanistic studies, including density functional theory (DFT) calculations, reveal that nucleophilic attack of ammonia on manganese imide complexes occurs to form a nitrogen-nitrogen bond leading to dinitrogen. [Extracted from the article]

Dual photoredox- and nickel-catalyzed hydroalkylation of terminal alkynes with 4-alkyl-1,4-dihydropyridines under visible light irradiation to afford Markovnikov- or anti-Markovnikov-type alkylated alkenes in good-to-high yields has been achieved, in which the regioselectivity of the products was effectively controlled by coordination ligands for nickel species. Using [NiCl 2 (dtbbpy)] as a catalyst led to the formation of Markovnikov-type products, whereas using NiCl 2  ⋅ 6 H 2 O led to the formation of anti-Markovnikov-type products., (© 2022 Wiley-VCH GmbH.)

A series of chromium-halide, -nitride, and -dinitrogen complexes bearing carbene- and phosphine-based PCP-type pincer ligands has been newly prepared, and some of them are found to work as effective catalysts to reduce dinitrogen under atmospheric pressure, whereby up to 11.60 equiv. of ammonia and 2.52 equiv. of hydrazine (16.6 equiv. of fixed N atom) are produced based on the chromium atom. To the best of our knowledge, this is the first successful example of chromium-catalyzed conversion of dinitrogen to ammonia and hydrazine under mild reaction conditions., (© 2022 Wiley-VCH GmbH.)

Invited for the cover of this issue are Ken Sakata, Yoshiaki Nishibayashi, and co-workers at The University of Tokyo and Toho University. The image depicts the propargylic substitution reaction of a propargylic alcohol with an N-monosubstituted hydrazone, where the nucleophilicity of the hydrazone is controlled by the choice of catalytic system. Read the full text of the article at 10.1002/chem.202103287., (© 2021 Wiley-VCH GmbH.)