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A concise Fe-catalyzed alkylazidation of α-trifluoromethylalkenes via a C-C bond cleavage/radical addition/azidation cascade is described. This protocol features a broad substrate scope, excellent functional group compatibility, and the ability to be performed on a gram scale, thus offering a practical and step-economic approach to the synthetically useful tertiary α-trifluoromethyl azides.

Switchable in situ SO 2 capture and CF 3 migration of enol triflates with peroxyl compounds under iron catalysis are presented. By regulating the structure of peroxides, a variety of keto-functionalized dialkyl sulfones and α-trifluoromethyl ketones were selectively synthesized in good yields under mild conditions.

Primary succession in mine tailings is a prerequisite for tailing vegetation. Microorganisms, including bacteria, fungi, and protists, play an important role in this process in the driving force for improving the nutritional status. Compared to bacteria and fungi, protist populations have rarely been investigated regarding their role in mine tailings, especially for those inhabiting tailings associated with primary succession. Protists are the primary consumers of fungi and bacteria, and their predatory actions promote the release of nutrients immobilized in the microbial biomass, as well as the uptake and turnover of nutrients, affecting the functions of the wider ecosystems. In this study, three different types of mine tailings associated with three successional stages (original tailings, biological crusts, and Miscanthus sinensis grasslands) were selected to characterize the protistan community diversity, structure, and function during primary succession. Some members classified as consumers dominated the network of microbial communities in the tailings, especially in the original bare land tailings. The keystone phototrophs of Chlorophyceae and Trebouxiophyceae showed the highest relative abundance in the biological crusts and grassland rhizosphere, respectively. In addition, the co-occurrences between protist and bacterial taxa demonstrated that the proportion of protistan phototrophs gradually increased during primary succession. Further, the metagenomic analysis of protistan metabolic potential showed that abundances of many functional genes associated with photosynthesis increased during the primary succession of tailings. Overall, these results suggest that the primary succession of mine tailings drives the changes observed in the protistan community, and in turn, the protistan phototrophs facilitate the primary succession of tailings. This research offers an initial insight into the changes in biodiversity, structure, and function of the protistan community during ecological succession on tailings., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Vanadium (V) is an important metal with critical industrial and medical applications. Elevated V contamination, however, can be a threat to the environment and human health. Microorganisms can reduce the more toxic and mobile V V to the less toxic and immobile V IV , which could be a detoxification and energy metabolism strategy adopted by V-reducing bacteria (VRB). The limited understanding of microbial responses to V contamination and the mechanisms for V V reduction, however, hamper our capability to attenuate V contamination. This study focused on determining the microbial responses to elevated V concentration and the mechanisms of V V reduction in V tailings. The bacterial communities were characterized and compared between the V tailings and the less contaminated adjacent mineral soils. Further, V V -reducing enrichments indicated that bacteria associated with Polaromonas , a genus belonging to the family Burkholderiaceae , were potentially responsible for V V reduction. Retrieved metagenome-assembled genomes (MAGs) suggested that the Polaromonas spp. encoded genes ( cymA , omcA , and narG ) were responsible for V V reduction. Additionally, Polaromonas spp. was metabolically versatile and could use both organic and inorganic electron donors. The metabolic versatility of Polaromonas spp. may be important for its ability to flourish in the V tailings.

The widespread application of sewage sludge produced from wastewater treatment plants for agricultural use has been regarded as a primary source of microplastics (MPs) into soils. However, little is known regarding MPs in sludge-based fertilizers and their relevant fate in soils as being applied in agriculture. We comprehensively investigated the abundance, polymer size, type, and morphology of MPs in dewatered sludge, sewage sludge composts, sludge-based fertilizer-amended soils, and earthworms by stereoscopy and micro Fourier transform infrared (μ-FTIR) spectrometry methods. The results clearly showed that the quantity of MPs in soils exhibited a close correlation with the application rate of sludge-based fertilizers. The total abundances of MPs were 545.9 and 87.6 items/kg in soils after annual amendment with 30 (field A) and 15 t/ha (field B) of sludge composts, which is significantly higher than that without compost application (field C, 5.0 items/kg). Correspondingly, MPs were found in earthworms with low quantities of 1.8 and 0.4 items/individual in fields A and B, respectively, while no MP was detected in field C. We speculate that sludge composts may act as a vehicle of MPs into soils and then enter soil biota and in turn influence the spread of MPs in the environment.

An iron-catalyzed decarboxylative olefination of unstrained carbon-carbon bonds via alkoxyl radical induced C-C bond cleavage is presented. This protocol features mild conditions (room temperature, redox-neutral), good substrate scope and functional group compatibility, as well as excellent stereoselectivity, thus providing a facile access to the distal alkenyl ketones.

The efficient copper-catalyzed cyanoalkylation of amines via C-C bond cleavage has been demonstrated. Distinctive features of this procedure involves mild conditions, broad range of nitrogen nucleophiles, high selectivity, and good functional group tolerance, thus providing a useful approach for the C(sp 3 )-N bond formations. Most importantly, this protocol is applicable to the late-stage functionalization of natural products, amino acid esters, and drugs. Mechanistic studies suggest that a radical intermediate was involved in this transformation.

An efficient iron-catalyzed intermolecular remote C(sp 3 )-H heteroarylation of alkyl ketones has been developed via an iminyl radical-triggered 1,5-hydrogen-atom transfer (HAT) cascade. This protocol was amenable to a wide variety of alkyl ketones and heteroaryls, thus providing a straightforward method for the late-stage functionalization of alkylketones and heteroaryls.

An efficient synthesis of cyanoalkylated heteroarenes via iron-catalyzed direct C-H cyanoalkylation of heteroarenes has been developed. Structurally diverse cyanoalkyl motifs generated through C-C bond cleavage of cyclobutanone oxime esters have been introduced into quinoxalin-2(1H)-ones, flavone, benzothiazoles, and caffeine in good to excellent yields. Remarkably, less-strained cyclopentanone and unstrained cyclohexanone oxime esters were also amenable substrates in this cyanoalkylation reaction.

The copper-catalyzed cyclization of activated alkenes with cyclobutanone O-acyl oximes under redox-neutral conditions has been reported. This facile protocol provided an efficient approach to a variety of cyanoalkylated oxindoles and dihydroquinolin-2(1H)-ones with a broad substrate scope and excellent functional group tolerance. In this reaction, sequential C-C bond cleavage, radical addition, and cyclization processes were involved, wherein multiple bonds were constructed in a one-pot reaction. Mechanistic studies suggest that the reaction probably proceeded via a radical pathway.

A novel strategy of silylation and dearomatization of activated alkynes with silanes to synthesize azaspiro[4,5]trienones is developed, which could be facilely achieved through a tandem difunctionalization of alkyne, dearomatization, and oxidation and provided a facile approach to produce useful 3-silyl azaspiro[4,5]trienones in an efficient manner.

A new method for the AgSCF3-mediated radical cascade difunctionalizing trifluoromethythiolation of alkynes with dearomatization is developed. This protocol provides a novel route to SCF3-substituted spirocyclic compounds via the formation of one C-SCF3 bond, one C-C bond, and one C-O double bond in a single step.

A novel BF3·Et2O-promoted tandem reaction of easily prepared 2-propynolphenols/anilines and trimethylsilyl azide is developed to give C2-alkenylated benzoxazoles and benzimidazoles in moderate to good yields. Most reactions could be accomplished in 30 min at room temperature. This tandem process involves a Csp-Csp2 bond cleavage and a C-N bond formation. Moreover, both tertiary and secondary propargylic alcohols with diverse functional groups were tolerated under the mild conditions.

A novel iron-catalyzed aerobic oxidative reaction to synthesize disubstituted isoxazoles from homopropargylic alcohol, t-BuONO, and H2O is developed. The method provides mild conditions to afford a variety of useful substituted heterocycles in an efficient and regioselective manner. The mechanism has been studied and proposed, which indicates that the transformation can be realized through construction of a C═N bond and C═O bond, C-H oxidation, and then cyclization. Moreover, this method can be enlarged to gram scale.

A palladium-/copper-catalyzed intermolecular C-H amination reaction of indoles has been developed. This reaction proceeds in good to excellent yields to produce a variety of 2-amino-substituted indoles and exhibits excellent regioselectivity at room temperature. Furthermore, chloroamination of indoles provides a simple method for the construction of C-N and C-Cl bonds in one step., (© 2011 American Chemical Society)