cross-coupling represents an ideal way for the construction of new chemical bonds. However, the bond formation with loss of H 2 is typically thermodynamically unfavorable and thus usually requires an external driving force, namely, an appropriate sacrificial oxidant. Recent advances have revealed that oxidative R 1 -H/R 2 -H cross-coupling with hydrogen gas evolution can be achieved through electrochemical anodic oxidation and concomitant cathodic proton reduction. Electrochemistry provides new opportunities for the construction of carbon-carbon and carbon-heteroatom bonds in an environmentally friendly manner. This review article gives an overview of the recent developments in this emerging field.

Ethylene and ethyne are among the simplest two-carbon building blocks. However, quite limited methods can be applied to incorporate ethylene or ethyne into fine chemicals. Here we demonstrate a cobalt-catalyzed dehydrogenative C–H/N–H [4+2] annulation of aryl/vinyl amides with ethylene or ethyne by using an electrochemical reaction protocol. Significantly, this work shows an example of electrochemical recycling of cobalt catalyst in oxidative C–H functionalization reactions, avoiding the use of external chemical oxidants and co-oxidants. The electrochemical method provides a reliable and safe way for incorporating gas-phase ethylene or ethyne into fine chemicals. High reaction efficiency and good functional group tolerance are observed under divided electrolytic conditions.

Dehydrogenative C-H/N-H cross-coupling serves as one of the most straightforward and atom-economical approaches for C-N bond formation. In this work, an electrochemical reaction protocol has been developed for the oxidative C-H amination of unprotected phenols under undivided electrolytic conditions. Neither metal catalysts nor chemical oxidants are needed to facilitate the dehydrogenation process. A series of triarylamine derivatives could be obtained with good functional-group tolerance. The electrolysis is scalable and can be performed at ambient conditions.

Cross‐coupling reactions have developed widely and provided a powerful means to synthesize a variety of compounds in each chemical field. The compounds which have C—H bonds are widespread in fossil fuels, chemical raw materials, biologically active molecules, etc. Using these readily‐ available substances as substrates is high atom‐ and step‐economy for cross‐coupling reactions. Over the past decades, our research group focused on finding and developing new strategies for C—H functionalization. Compared with classical C—H activation methods, for example, C—H bonds are deprotonated by strong base or converted into C—M bonds, oxidation‐induced C—H functionalization would be another pathway for C—H bond activation. This perspective shows a brief introduction of our recent works in this oxidation‐induced C—H functionalization. We categorized this approach of these C—H bond activations by the key intermediates, radical cations, radicals and cations.

Among the alternative sigma factors of Listeria monocytogenes, σ B controls the largest regulon. The aim of this study was to perform a comprehensive review of σ B -regulated genes, and the functions they confer. Materials & methods: A systematic search of PubMed and Web of Knowledge was carried out to identify members of the σ B regulon based on experimental evidence of σ B -dependent transcription and presence of a consensus σ B -dependent promoter. Results: The literature review identified σ B -dependent transcription units encompassing 304 genes encoding different functions including stress response and virulence. Conclusion: Our review supports the well-known roles of σ B in virulence and stress response and provides new insight into novel roles for σ B in metabolism and overall resilience of L. monocytogenes.

Both bile acids and short-chain fatty acids can modulate serotonin metabolism in hosts by affecting key intermediates of the serotonin pathway. Thus, gut motility may be regulated through microbial modifications of host serotonin biosynthesis, which continues to be evaluated as a target for functional gastrointestinal disorders.

Electrochemical synthesis has been rapidly developed over the past few years, while a vast majority of the reactions proceed through a radical pathway. Understanding the properties of radical intermediates is crucial in the mechanistic study of electrochemical transformations and will be beneficial for developing new reactions. Nevertheless, it is rather difficult to determine the “live” radical intermediates due to their high reactivity. In this work, the formation and structure of sulfonamide N-centered radicals have been researched directly by using the time-resolved electron paramagnetic resonance (EPR) technique under electrochemical conditions. Supported by the EPR results, the reactivity of N-centered radicals as a mediator in the hydrogen atom transfer (HAT) approach has been discussed. Subsequently, these mechanistic study results have been successfully utilized in the discovery of an unactivated C­(sp3)–H arylation reaction. The kinetic experiments have revealed the rate-determined step is the anodic oxidation of sulfonamides.

Among Listeria monocytogenes' four alternative σ factors, σB controls the largest regulon. As σB-dependent transcription of some genes may be masked by overlaps among regulons, and as some σB-dependent genes are expressed only under very specific conditions, we hypothesized that the σB regulon is not yet fully defined. To further extend our understanding of the σB regulon, we used RNA-seq to identify σB-dependent genes in an L. monocytogenes strain that expresses σB following rhamnose induction, and in which genes encoding the other alternative sigma factors have been deleted. Analysis of RNA-seq data with multiple bioinformatics approaches, including a sliding window method that detects differentially transcribed 5′ untranslated regions (UTRs), identified 105 σB-dependent transcription units (TUs) comprising 201 genes preceded by σB-dependent promoters. Of these 105 TUs, 7 TUs comprising 15 genes had not been identified previously as σB-dependent. An additional 23 genes not reported previously as σB-dependent were identified in 9 previously recognized σB-dependent TUs. Overall, 38 of these 201 genes had not been identified previously as members of the L. monocytogenes σB regulon. These newly identified σB-dependent genes encode proteins annotated as being involved in transcriptional regulation, oxidative and osmotic stress response, and in metabolism of energy, carbon and nucleotides. In total, 18 putative σB-dependent promoters were newly identified. Interestingly, a number of genes previously identified as σB-dependent did not show significant evidence for σB-dependent transcription in our experiments. Based on promoter analyses, a number of these genes showed evidence for co-regulation by σB and other transcriptional factors, suggesting that some σB-dependent genes require additional transcriptional regulators along with σB for transcription. Over-expression of a single alternative sigma factor in the absence of all other alternative sigma factors allowed us to: (i) identify new σB-dependent functions in L. monocytogenes, such as regulation of genes involved in 1,2-propanediol utilization (LMRG_00594-LMRG_00611) and biosynthesis of pyrimidine nucleotides (LMRG_00978-LMRG_00985); and (ii) identify new σB-dependent genes involved in stress response and pathogenesis functions. These data further support that σB not only regulates stress response functions, but also plays a broad role in L. monocytogenes homeostasis and resilience.