Transition-metal-catalyzed C–N bond-forming reactions have emerged as fundamental and powerful tools to construct arylamines, a common structure found in drug agents, natural products, and fine chemicals. Reported herein is an alternative access to heteroarylamine via radical–radical cross-coupling pathway, powered by visible light catalysis without any aid of external oxidant and reductant. Only by visible light irradiation of a photocatalyst, such as a metal-free photocatalyst, does the cascade single-electron transfer event for amines and heteroaryl nitriles occur, demonstrated by steady-state and transient spectroscopic studies, resulting in an amine radical cation and aryl radical anion in situ for C–N bond formation. The metal-free and redox economic nature, high efficiency, and site-selectivity of C–N cross-coupling of a range of available amines, hydroxylamines, and hydrazines with heteroaryl nitriles make this protocol promising in both academic and industrial settings.

Inspired by the cubic Mn CaO cluster of natural oxygen-evolving complex in Photosystem II, tetrametallic molecular water oxidation catalysts, especially M O cubane-like clusters (M=transition metals), have aroused great interest in developing highly active and robust catalysts for water oxidation. Among these M O clusters, however, copper-based molecular catalysts are poorly understood. Now, bio-inspired Cu O cubanes are presented as effective molecular catalysts for electrocatalytic water oxidation in aqueous solution (pH 12). The exceptional catalytic activity is manifested with a turnover frequency (TOF) of 267 s for [(L -Cu) ] at 1.70 V and 105 s for [(L -Cu) ] at 1.56 V. Electrochemical and spectroscopic study revealed a successive two-electron transfer process in the Cu O cubanes to form high-valent Cu and Cu O intermediates during the catalysis.

Semiconductor quantum dots (QDs) in conjunction with non-noble 3d-metal ions (e.g., Fe 3+ , Co 2+ , and Ni 2+ ) have emerged as an extremely efficient, facile, and cost-effective means of solar-driven hydrogen (H 2 ) evolution. However, the exact structural change of the active sites under realistic conditions remains elusive, and the mechanism of H 2 evolution behind the remarkable activity is poorly understood. Here, we successfully track the structural variation of the catalytic sites in the typical H 2 photogeneration system consisting of CdSe/CdS QDs and 3d-metal ions (i.e., Ni 2+ used here). That is, the nickel precursor of Ni(OAc) 2 changes to Ni(H 2 O) 6 2+ in neutral H 2 O and eventually transforms to Ni(OH) 2 nanosheets in alkaline media. Furthermore, the in operando spectroscopic techniques of electron paramagnetic resonance and X-ray absorption spectroscopy reveal the photoinduced transformation of Ni(OH) 2 to a defective structure [Ni x 0 /Ni 1−x (OH) 2 ], which acts as the real catalytic species of H 2 photogeneration. Density functional theory (DFT) calculations further indicate that the surface Ni-vacancies (V Ni ) on the Ni(OH) 2 nanosheets enhance the adsorption and dissociation of H 2 O molecules to enhance the local proton concentration, while the Ni 0 clusters behave as H 2 -evolution sites, thereby synergistically promoting the activity of H 2 photogeneration in alkaline media.

Inspired by the cubic Mn 4 CaO 5 cluster of natural oxygen-evolving complex in Photosystem II, tetrametallic molecular water oxidation catalysts,e specially M 4 O 4 cubanelike clusters (M = transition metals), have aroused great interest in developing highly active and robust catalysts for water oxidation. Among these M 4 O 4 clusters,however,copperbased molecular catalysts are poorly understood. Now,b ioinspired Cu 4 O 4 cubanes are presented as effective molecular catalysts for electrocatalytic water oxidation in aqueous solution (pH 12). The exceptional catalytic activity is manifested with at urnover frequency (TOF) of 267 s À1 for [(L Gly -Cu) 4 ]at1.70 Vand 105 s À1 for [(L Glu -Cu) 4 ]at1.56 V. Electrochemical and spectroscopic study revealed as uccessive twoelectron transfer process in the Cu 4 O 4 cubanes to form highvalent Cu III and Cu III OC intermediates during the catalysis.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

[2+2] Photocycloaddition of two olefins is a general method to assemble the core scaffold, cyclobutane, found in numerous bioactive molecules. A new approach to synthesize cyclobutanes through multicomponent cascade reactions by merging aldol reaction and Witting reaction with visible‐light‐induced [2+2] cycloaddition is reported. An array of cyclobutanes with high selectivity has been achieved from commercially available aldehydes, ketones (or phosphorus ylide), and olefins with visible‐light irradiation of a catalytic amount of (fac‐tris(2‐phenylpyridinato‐C2,N)iridium) ([Ir(ppy)3]) at room temperature. Control experiments and spectroscopic studies revealed that the triplet–triplet energy transfer from the excited [Ir(ppy)3]* to enones, generated in situ from aldehyde and ketone or aldehyde and phosphorus ylide, is responsible for these simple and efficient muticomponent transformations.

We describe here an approach for synthesizing quinolines either from N-alkyl anilines or from anilines and aldehydes. A dual-catalyst system consisting of a photocatalyst and a proton reduction cocatalyst is employed. Without the use of any sacrificial oxidant and under extremely mild conditions, the reactions afford quinolines in excellent yields and produce H2 as a byproduct.

High‐valent iron‐oxo species are appealing for conducting O−O bond formation for water oxidation reactions. However, their high reactivity poses a great challenge to the dissection of their chemical transformations. Herein, we introduce an electron‐rich and oxidation‐resistant ligand, 2‐[(2,2′‐bipyridin)‐6‐yl]propan‐2‐ol to stabilize such fleeting intermediates. Advanced spectroscopies and electrochemical studies demonstrate a high‐valent FeV(O) species formation in water. Combining kinetic and oxygen isotope labelling experiments and organic reactions indicates that the FeV(O) species is responsible for O−O bond formation via water nucleophilic attack under the real catalytic water oxidation conditions.

A nickel-based ultrathin catalyst film is assembled in situ from a solution of Ni(OAc)2 and Schiff-base ligand L (L = 3-methoxy-salicylidene-glycine). The resulting ultrathin catalyst film shows a low overpotential...