An efficient and straightforward approach for the synthesis of carbamoylated chroman-4-ones has been well-developed. The reaction is triggered through the generation of carbamoyl radicals from oxamic acids under metal-free conditions, which subsequently undergoes decarboxylative radical cascade cyclization on 2-(allyloxy)arylaldehydes to afford various amide-containing chroman-4-one scaffolds with high functional group tolerance and a broad substrate scope.

Background/Objectives: Chemical fumigation can effectively inhibit the occurrence of soil-borne diseases; however, this approach can negatively affect the structure of the soil microbial community. The combination of soil fumigant and organic fertilizer application thus represents a widely adopted strategy in agricultural practice. Traditional Chinese medicine residue (TCMR) is a high-quality organic fertilizer; however, the impact of post-fumigation TCMR application on keystone taxa and their functional traits remains uncertain. Methods: This study examined the effects of five fertilization treatments on the diversity, key species, and related functional genes of microbial communities in rhizosphere soil of continuous cropping pepper. Results: Chemical fumigation followed by TCMR application markedly enhanced soil nutrient content in the rhizosphere and significantly influenced microbial community composition as well as functional gene patterns associated with microbial nitrogen cycling. It was also strongly correlated with soil bioavailable nitrogen content. The abundance of keystone bacterial species (Pseudomonadota, Actinomycetota, and Bacillota) substantially increased following TCMR application, alongside a notable rise in Ascomycota abundance within the fungal community. This shift contributed to an increase in beneficial bacterial abundance while reducing that of harmful bacteria. Additionally, TCMR addition affected the abundance of denitrification and DNRA genes involved in nitrogen cycling; specifically, nirB and nirK were strongly associated with soil organic nitrogen content. Conclusions: The combined application of chemical fumigants and TCMR modified the composition of keystone microbial community species by influencing rhizosphere soil TN and other nutrients, and these alterations were linked to multiple nitrogen-cycling functional genes.

Continuous pepper cropping induces soil-borne diseases and disrupts rhizosphere microecological balance. This study employed untargeted metabolomics and metagenomics to investigate treatment effects on rhizosphere metabolic reprogramming and microbe–metabolite interactions. Aqueous and ethanolic extracts of Andrographis paniculata residues (TCMR) were rich in flavonoids, terpenoids, and phenolic acids, exhibiting significant inhibition against soil-borne pathogens (Fusarium oxysporum, Fusarium solani, and others; >70% inhibition at high doses). While single fumigation (W1, M1) transiently suppressed pathogens, it disrupted rhizosphere metabolic homeostasis. In contrast, combined fumigation-TCMR treatments (WC, MC) enhanced plant stress resistance, stabilized membrane integrity, and reshaped microbial communities by modulating amino acid, lipid, and phenylpropanoid biosynthesis pathways. Microbe–metabolite network analysis revealed that coupling carbon–nitrogen cycling with redox homeostasis drives soil microecological optimization. This integrated strategy provides a sustainable solution for continuous cropping obstacles through synergistic metabolic reprogramming and microbiome reconstruction.

Continuous cropping obstacles in pepper (Capsicum annuum L.) arise from soil degradation and pathogen accumulation. The combination of soil fumigant and Tr

A convenient and practical method for the synthesis of bioactive ester-containing chroman-4-ones through the cascade radical cyclization of 2-(allyloxy)arylaldehydes and oxalates is described. The preliminary studies suggest that an alkoxycarbonyl radical might be involved in the current transformation, which was generated via the decarboxylation of oxalates in the presence of (NH₄)₂S₂O₈.

Shallow wetlands retain metals and metalloids from industrial, mining, agricultural, urban, and atmospheric sources; however, shallow water columns, active sediment–water exchange, and recurrent wetting–drying also favor remobilization. This critical narrative review evaluates physical, chemical, biological, and ecological engineering approaches for metal-contaminated shallow wetlands, focusing on the hydrological and biogeochemical conditions governing performance. Evidence was differentiated among natural or semi-natural wetlands, engineered wetland analogues, and transferable studies of contaminated sediments, soils, or wastewaters. Physical interventions rapidly control localized sediment inventories but can disturb habitats and redistribute particles. Chemical amendments reduce porewater concentrations and bioavailability, although durability depends on pH, redox conditions, dissolved organic matter, and competing ions. Biological and ecological engineering approaches can support ecological function recovery, but performance depends on plant traits, microbial processes, hydroperiod, and maintenance. No intervention was consistently superior across site conditions and outcome domains. Within this framework, sustainability is evaluated through durable risk reduction, ecological function recovery, life-cycle feasibility, responsible residual management, and accountable long-term stewardship. The reviewed mechanistic and conceptual evidence supports considering site-specific treatment trains, although direct comparative field evidence demonstrating their superiority over individual interventions remains limited. Future studies should prioritize hydrologically realistic field validation, standardized flux and bioavailability endpoints, mixed-contaminant scenarios, life-cycle assessment, and explicit measurement of ecological function recovery.