The direct C–H bond amination represents one of the most straightforward and efficient strategies for C–N bond construction. However, conventional transition metal catalytic systems suffer from critical drawbacks, such as dependence on stoichiometric bases, high reaction temperatures, stringent inert atmosphere requirements, and poor catalyst recyclability. Herein, we report the development of an integrated heterogeneous polyoxoniobate (PONb) catalyst, Cu/FZU-1, achieved via the precise anchoring of catalytically active Cu sites onto an alkaline Nb-oxo cluster. The Cu/FZU-1 exhibited remarkable catalytic performance and recyclability in the direct amination of C–H bonds under mild conditions, achieving excellent yields up to 94% and an outstanding turnover number (TON) of 78. Its remarkable catalytic performance arises from the synergistic interplay of two key components within the integrated catalyst: Nb-oxo polyoxoanions provide Brønsted basicity and anchoring Cu²⁺ ions at the dangling sites serve as active sites for C–H bond activation. This integrated catalyst not only overcomes the bottleneck of low efficiency in the reaction interface, but also provides a new paradigm for precisely identifying active sites at the atomic level in complex catalytic systems.

A novel sandwich-type thorium-substituted phosphotungstate, [H₂N(CH₃)₂]₁₀[Th(PW₁₁O₃₉)₂]·24H₂O (ThP₂W₂₂), was synthesized and fully characterized. The structure consists of two monolacunary Keggin-type [PW₁₁O₃₉]⁷⁻ units bridged by an eight-coordinate Th⁴⁺ center. ThP₂W₂₂ functions as an efficient Lewis acid catalyst for the synthesis of 2,3-dihydroquinazolinones via cyclization of 2-aminobenzamides with aldehydes. A series of quinazolinone derivatives was obtained in high yields (75%–92%) under mild and green reaction conditions. Control experiments indicate a synergistic interaction between the Th⁴⁺ center and the polyoxometalate framework, highlighting the potential of thorium-containing polyoxometalates as catalysts for heterocycle synthesis.

Photo-excited holes usually migrate to the surface of the catalyst and rapidly recombine with electrons, reducing the photocatalytic reduction efficiency of uranium(VI) (U(VI)) in radioactive wastewater. Consequently, we employed a straightforward synthesis technique to meticulously shape and manipulate the morphology of CdS to precisely construct CdS-Ni dandelion-like composites with different aspect ratios. Briefly, the introduction of crystal facet homojunction with Ohmic contacts in this unique morphology siqnificantly improves the photocatalytic efficiency. Temperature-dependent photoluminescence spectroscopy (TD-PL) verifies that the composite material positively effects on the dissociation of excitons. Within 30 min, CdS(002)/(102)/Ni-4 removed 98% of the uranium content in solution and showed a rather high apparent rate constant (0.114 min⁻¹), which was 4.8 times higher than that of CdS nanospheres (NSs) (0.024 min⁻¹) and 3.7 times higher than that of CdS nanorods (NRs) (0.031 min⁻¹). This is much higher the most reported photocatalysts for U(VI) reduction. Even after 5 consecutive cycles, the photocatalytic efficiency only decreased by 7%. This offers a fresh perspective on constructing a new perspective for building a green, efficient, and multi mechanism collaborative catalytic system to remediate environmental pollution.

N-Heterocycle compounds are crucial scaffolds in natural products, synthetic molecules, agricultural chemicals, and pharmaceuticals. Hence, green catalytic systems for the synthesis of N-heterocycles have been widely researched in organic synthesis and industrial catalysis. Polyoxometalates (POMs) are polynuclear metal–oxygen clusters with diverse structures and physicochemical properties. POMs exhibit multiple advantageous properties such as adjustable acidity, redox properties, high thermal stability, and nontoxic nature. Therefore, POMs have been widely investigated for their application in N-heterocycles synthesis and held great potential for industrial applications. In this review, we summarize recent advances (mainly from 2010 to 2023) in the synthesis of N-heterocycles, such as pyrroles, indoles, pyridines, and benzodiazepines, catalyzed by heteropolyacids (HPAs), modified HPA catalysts, and transition metal-modified POMs. The prospects of POM-based catalytic systems for the synthesis of N-heterocycles are also outlined.