The primordial differentiation of tumor-specific memory CD8+ T cells as bona fide responders to PD-1/PD-L1 blockade in draining lymph nodes.

Blocking PD-1/PD-L1 signaling transforms cancer therapy and is assumed to unleash exhausted tumor-reactive CD8+ T cells in the tumor microenvironment (TME). However, recent studies have also indicated that the systemic tumor-reactive CD8+ T cells may respond to PD-1/PD-L1 immunotherapy. These discrepancies highlight the importance of further defining tumor-specific CD8+ T cell responders to PD-1/PD-L1 blockade. Here, using multiple preclinical tumor models, we revealed that a subset of tumor-specific CD8+ cells in the tumor draining lymph nodes (TdLNs) was not functionally exhausted but exhibited canonical memory characteristics. TdLN-derived tumor-specific memory (TTSM) cells established memory-associated epigenetic program early during tumorigenesis. More importantly, TdLN-TTSM cells exhibited superior anti-tumor therapeutic efficacy after adoptive transfer and were characterized as bona fide responders to PD-1/PD-L1 blockade. These findings highlight that TdLN-TTSM cells could be harnessed to potentiate anti-tumor immunotherapy.

Salmonella Enteritidis T1SS protein SiiD inhibits NLRP3 inflammasome activation via repressing the mtROS-ASC dependent pathway.

Inflammasome activation is an essential innate immune defense mechanism against Salmonella infections. Salmonella has developed multiple strategies to avoid or delay inflammasome activation, which may be required for long-term bacterial persistence. However, the mechanisms by which Salmonella evades host immune defenses are still not well understood. In this study, Salmonella Enteritidis (SE) random insertion transposon library was screened to identify the key factors that affect the inflammasome activation. The type I secretion system (T1SS) protein SiiD was demonstrated to repress the NLRP3 inflammasome activation during SE infection and was the first to reveal the antagonistic role of T1SS in the inflammasome pathway. SiiD was translocated into host cells and localized in the membrane fraction in a T1SS-dependent and partially T3SS-1-dependent way during SE infection. Subsequently, SiiD was demonstrated to significantly suppress the generation of mitochondrial reactive oxygen species (mtROS), thus repressing ASC oligomerization to form pyroptosomes, and impairing the NLRP3 dependent Caspase-1 activation and IL-1ß secretion. Importantly, SiiD-deficient SE induced stronger gut inflammation in mice and displayed NLRP3-dependent attenuation of the virulence. SiiD-mediated inhibition of NLRP3 inflammasome activation significantly contributed to SE colonization in the infected mice. This study links bacterial T1SS regulation of mtROS-ASC signaling to NLRP3 inflammasome activation and reveals the essential role of T1SS in evading host immune responses.

Capsaicin enhances cisplatin-induced anti-metastasis of nasopharyngeal carcinoma by inhibiting EMT and ERK signaling via SERPINB2.

Cisplatin (DDP)-based combined chemotherapy or concurrent chemoradiotherapy is the mainstay treatment for advanced-stage nasopharyngeal carcinoma (NPC), but needs improvement due to its severe side effects. Capsaicin (CAP) can enhance the anti-tumor activity of cytotoxic drugs. The aim of this study was to investigate the anti-metastasis activity of CAP in combination with DDP in NPC. Herein, CAP and DDP showed synergistic cytotoxic effects on NPC cells. CAP alone and DDP alone inhibited NPC migration and invasion in vitro and in vivo, and the combination of CAP and DDP had the greatest effect. Moreover, CAP upregulated the mRNA and protein expressions of SERPINB2. Further results showed that both SERPINB2 mRNA and protein expressions were downregulated in NPC cell lines and tissues and SERPINB2 overexpression inhibited NPC migration and invasion in vitro and in vivo, while silencing SERPINB2 acted oppositely. In addition, SERPINB2 was abnormally expressed in head and neck squamous cell carcinoma (HNSC) and other multiple cancers and downregulation of SERPINB2 predicted poor prognosis in HNSC according to the Cancer Genome Atlas (TCGA) database. We further found that SERPINB2 overexpression inhibited epithelial-mesenchymal transition (EMT) and the phosphorylated ERK (p-ERK), and the inhibitory effect was enhanced by CAP and DDP. Altogether, our results suggest that the combined inhibition of CAP and DDP on NPC metastasis may be related to the inhibition of EMT and ERK signals mediated by SERPINB2, and CAP may help to improve the efficacy of DDP in the treatment of NPC and develop new therapeutic approaches.

A metabolic map and artificial intelligence-aided identification of nasopharyngeal carcinoma via a single-cell Raman platform.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a complex cancer influenced by various factors. This study explores the use of single-cell Raman spectroscopy as a potential diagnostic tool for investigating biomolecular changes associated with NPC carcinogenesis. METHODS: Seven NPC cell lines, one immortalised nasopharyngeal epithelial cell line, six nasopharyngeal mucosa tissues and seven NPC tissue samples were analysed by performing confocal Raman spectroscopic measurements and imaging. The single-cell Raman spectral dataset was used to quantify relevant biomolecules and build machine learning classification models. Metabolomic profiles were investigated using ultra-performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS). RESULTS: By generating a metabolic map of seven NPC cell lines, we identified an interplay of altered metabolic processes involving nucleic acids, amino acids, lipids and sugars. The results from spatially resolved Raman maps and UPLC-MS/MS metabolomics were consistent, revealing an increase of unsaturated fatty acids in cancer cells, particularly in highly metastatic 5-8F and poorly differentiated CNE2 cells. The classification model achieved a nearly perfect classification when identifying NPC and non-NPC cells with an ROC-AUC of 0.99 and a value of 0.97 when identifying 13 tissue samples. CONCLUSION: This study unveils a complex interplay of metabolic network and highlights the potential roles of unsaturated fatty acids in NPC progression and metastasis. This renders further research to provide deeper insights into NPC pathogenesis, identify new metabolic targets and improve the efficacy of targeted therapies in NPC. Artificial intelligence-aided analysis of single-cell Raman spectra has achieved high accuracies in the classification of both cancer cells and patient tissues, paving the way for a simple, less invasive and accurate diagnostic test.

Involvement of the Keap1-Nrf2-ARE pathway in the antioxidant activity of sinomenine.

Sinomenine is a pure alkaloid isolated from Sinomenium acutum. This study is aimed to investigate the critical role of the nuclear factor erythroid 2-related factor 2 (Nrf2)-kelch-like ECH-associated protein-1(Keap1)-antioxidant response element (ARE) antioxidative signaling pathway in protecting sinomenine against H2O2-induced oxidative injury. Cytotoxicity and antioxidant experiments to initially determine the protective effects of sinomenine show that sinomenine has no effect on the decreased cell viability and presents similar potency in scavenging all three free radicals. The binding affinity between sinomenine and Keap1 was determined via fluorescence polarization assay, with IC50 of 13.52 µM. Quantum chemical calculation and theoretical simulation illustrated that sinomenine located into the Nrf2-binding site of Keap1 via hydrophobic and hydrogen interactions, showing high stability and binding affinity. On the basis of the stable binding of sinomenine with Keap1, sinomenine efficiently induced nuclear translocation of Nrf2, and increased in ARE activity in a concentration-dependent manner. Quantitative polymerase chain reaction provided further evidences that sinomenine-induced protection upregulated ARE-dependent genes, such as NAD(P)H quinone oxidoreductase 1, hemeoxygenase-1, and glutamate-cysteine ligase modifier subunit. Western blot confirmed that sinomenine increased the expressions of these antioxidative enzymes. Taken together, in vitro and in silico evaluations demonstrate that sinomenine inhibits the binding of Keap1 to Nrf2, promotes the nuclear accumulation of Nrf2 and thus leads to the upregulated expressions of Nrf2-dependent antioxidative genes. Our findings also highlight the use of sinomenine for pharmacological or therapeutic regulation of the Nrf2-Keap1-ARE system, which is a novel strategy to prevent the progression of oxidative injury.

Characterisation of a SapYZU11@ZnFe2O4 biosensor reveals its mechanism for the rapid and sensitive colourimetric detection of viable Staphylococcus aureus in food matrices.

Although bacteriophage-based biosensors hold promise for detecting Staphylococcus aureus in food products in a timely, simple, and sensitive manner, the associated targeting mechanism of the biosensors remains unclear. Herein, a colourimetric biosensor SapYZU11@ZnFe2O4, based on a broad-spectrum S. aureus lytic phage SapYZU11 and a ZnFe2O4 nanozyme, was constructed, and its capacity to detect viable S. aureus in food was evaluated. Characterisation of SapYZU11@ZnFe2O4 revealed its effective immobilisation, outstanding biological activity, and peroxidase-like capability. The peroxidase activity of SapYZU11@ZnFe2O4 significantly decreased after the addition of S. aureus, potentially due to blockage of the nanozyme active sites. Moreover, SapYZU11@ZnFe2O4 can detect S. aureus from various sources and S. aureus isolates that phage SapYZU11 could not lyse. This may be facilitated by the adsorption of the special receptor-binding proteins on the phage tail fibre and wall teichoic acid receptors of S. aureus. Besides, SapYZU11@ZnFe2O4 exhibited remarkable sensitivity and specificity when employing colourimetric techniques to rapidly determine viable S. aureus counts in food samples, with a detection limit of 0.87 × 102 CFU/mL. Thus, SapYZU11@ZnFe2O4 has broad application prospects for the detection of viable S. aureus cells on food substrates.

dbCNV: deleteriousness-based model to predict pathogenicity of copy number variations.

BACKGROUND: Copy number variation (CNV) is a type of structural variation, which is a gain or loss event with abnormal changes in copy number. Methods to predict the pathogenicity of CNVs are required to realize the relationship between these variants and clinical phenotypes. ClassifyCNV, X-CNV, StrVCTVRE, etc. have been trained to predict the pathogenicity of CNVs, but few studies have been reported based on the deleterious significance of features. RESULTS: From single nucleotide polymorphism (SNP), gene and region dimensions, we collected 79 informative features that quantitatively describe the characteristics of CNV, such as CNV length, the number of protein genes, the number of three prime untranslated region. Then, according to the deleterious significance, we formulated quantitative methods for features, which fall into two categories: the first is variable type, including maximum, minimum and mean; the second is attribute type, which is measured by numerical sum. We used Gradient Boosted Trees (GBT) algorithm to construct dbCNV, which can be used to predict pathogenicity for five-tier classification and binary classification of CNVs. We demonstrated that the distribution of most feature values was consistent with the deleterious significance. The five-tier classification model accuracy for 0.85 and 0.79 in loss and gain CNVs, which proved that it has high discrimination power in predicting the pathogenicity of five-tier classification CNVs. The binary model achieved area under curve (AUC) values of 0.96 and 0.81 in the validation set, respectively, in gain and loss CNVs. CONCLUSION: The performance of the dbCNV suggest that functional deleteriousness-based model of CNV is a promising approach to support the classification prediction and to further understand the pathogenic mechanism.

Transcriptome Sequencing Reveals Salmonella Flagellin Activation of Interferon-ß-Related Immune Responses in Macrophages.

The flagellin (FliC) of Salmonella typhimurium is a potential vaccine adjuvant as it can activate innate immunity and promote acquired immune responses. Macrophages are an important component of the innate immune system. The mechanism of flagellin's adjuvant activity has been shown to be related to its ability to activate macrophages. However, few studies have comprehensively investigated the effects of Salmonella flagellin in macrophages using transcriptome sequencing. In this study, RNA-Seq was used to analyze the expression patterns of RAW264.7 macrophages induced by FliC to identify novel transcriptomic signatures in macrophages. A total of 2204 differentially expressed genes were found in the FliC-treated group compared with the control. Gene ontology and KEGG pathway analyses identified the top significantly regulated functional classification and canonical pathways, which were mainly related to immune responses and regulation. Inflammatory cytokines (IL-6, IL-1ß, TNF-α, etc.) and chemokines (CXCL2, CXCL10, CCL2, etc.) were highly expressed in RAW264.7 cells following stimulation. Notably, flagellin significantly increased the expression of interferon (IFN)-ß. In addition, previously unidentified IFN regulatory factors (IRFs) and IFN-stimulated genes (ISGs) were also significantly upregulated. The results of RNA-Seq were verified, and furthermore, we demonstrated that flagellin increased the expression of IFN-ß and IFN-related genes (IRFs and ISGs) in bone marrow-derived dendritic cells and macrophages. These results suggested that Salmonella flagellin can activate IFN-ß-related immune responses in macrophages, which provides new insight into the immune mechanisms of flagellin adjuvant.

Identification of signalling downstream of the transcription factor forkhead box protein M1 that protects against endoplasmic reticulum stress in a diabetic foot ulcer model.

AIMS: Diabetic foot ulcer (DFU) has a significant impact on the quality of life of diabetic mellitus (DM) patients. Here, we aimed to explore the molecules with aberrant expression and their regulatory mechanisms in DFU. METHODS: The expression of gene and protein was examined using quantitative polymerase chain reaction (qPCR) and western blot. Pearson's correlation analysis was used to analyse interactions among FOXM1, GAS5 and SDF4. Immunofluorescence was used to detect PDI and GRP78 expression. Flow cytometry was used to assess cell apoptosis. Tube formation assay was used to determine angiogenic capacity. Fluorescence in situ hybridization (FISH) assay was employed to determine the cellular localization of GAS5 and SDF4 in human umbilical vein endothelial cells (HUVECs). The interactions among FOXM1, GAS5 and SDF4 were validated by chromatin immunoprecipitation (ChIP), luciferase, RNA pull-down and RNA immunoprecipitation (RIP) assays. RESULTS: FOXM1, GAS5 and SDF4 were decreased in the skin tissues of DFU patients. High glucose (HG) stimulation induced endoplasmic reticulum (ER) stress and cell apoptosis but suppressed angiogenesis in HUVECs, which were abolished by FOXM1 overexpression. FOXM1 promoted GAS5 transcriptional activity, resulting in increased GAS5 expression, and GAS5 knockdown reversed the effects of FOXM1 overexpression in HG-treated HUVECs. Moreover, GAS5 recruited TAF15 to promote SDF4 expression in HUVECs. GAS5 overexpression inhibited ER stress, cell apoptosis and induced angiogenesis in HG-treated HUVECs which could be reversed by silencing SDF4. CONCLUSION: Our results revealed that FOXM1 suppressed ER stress, cell apoptosis and promoted angiogenesis in HG-induced HUVECs via mediating GAS5/TAF15/SDF4 axis, providing a novel therapeutic molecule mechanism for DFU.

Rapid detection of SARS-CoV-2 with CRISPR-Cas12a.

The recent outbreak of betacoronavirus Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which is responsible for the Coronavirus Disease 2019 (COVID-19) global pandemic, has created great challenges in viral diagnosis. The existing methods for nucleic acid detection are of high sensitivity and specificity, but the need for complex sample manipulation and expensive machinery slow down the disease detection. Thus, there is an urgent demand to develop a rapid, inexpensive, and sensitive diagnostic test to aid point-of-care viral detection for disease monitoring. In this study, we developed a clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR associated proteins (Cas) 12a-based diagnostic method that allows the results to be visualized by the naked eye. We also introduced a rapid sample processing method, and when combined with recombinase polymerase amplification (RPA), the sample to result can be achieved in 50 minutes with high sensitivity (1-10 copies per reaction). This accurate and portable detection method holds a great potential for COVID-19 control, especially in areas where specialized equipment is not available.

Alkali-Amide-Catalyzed One-Pot Aminoallylation of Aldehydes with Allylbenzenes.

The deprotonation of allylbenzene was successfully demonstrated with a catalytic alkali amide base (NaN(SiMe3)2). The deprotonated allyl anion could be trapped by in situ generated N-(trimethylsilyl) aldimines to provide value-added homoallylic amines (39 examples, 68-98% yields) in a one-pot manner with excellent liner selectivity. Compared with the previously reported method for the synthesis of homoallylic amines, this method does not need to use the preinstalled protection groups on the imines, which need to be removed after the reaction to obtain the N-H free homoallylic amine derivatives.

The Comparison of Biomolecular Changes of Epstein-Barr Virus Infection in Nasopharyngeal Epithelial Cells Using Confocal Raman Microspectroscopy.

BACKGROUND: Due to its unique fingerprinting properties, Confocal Raman microscopy (CRM) can be used to examine the biomolecular changes of viruses invading and manipulating host cells. Recently, the biochemical changes due to the invasion and infection of B lymphocyte cells, nerve cells, and epithelial cells by Epstein-Barr virus (EBV) have been reported. However, biomolecular changes in nasopharyngeal epithelial cells that result from EBV infection are still poorly understood. METHODS: In continuation of our prior investigation of EBV infection in nasopharyngeal epithelial cells, we tried to expound on biomolecular changes in EBV-infected nasopharyngeal epithelial cells using Raman microspectroscopy. EBV has two life cycles, latent infection and lytic replication. We have established latent and lytic infection models at the cellular level. In order to understand the characteristics of the two patterns of EBV infection, we used Raman spectroscopy to identify the changes in biomolecules of EBV latent cells (CNE2, CNE2-EBV) and lytic cells (NPEC1-BMI1-CN, NPEC1-BMI1-EBV). RESULTS: During latent infection, levels of glycogen, protein, and lipid molecules in the cell increased while levels of nucleic acid and collagen molecules decreased. Molecular levels of glycogen, proteins, and nucleic acids are reduced during lytic infection. We found that molecular levels of nucleic acid decreased during two different periods of infection, whereas levels of other biomolecules showed the opposite trend. Glycogen, proteins, lipids, nucleic acids, and other molecules are associated with alterations in cellular biochemical homeostasis. These changes correspond to unique Raman spectra in infected and uninfected cells associated with specific biomolecules that have been proven. These molecules are mainly responsible for cellular processes such as cell proliferation and apoptosis. The Raman signatures of these biomolecular changes depend on the different phases of viral infection. CONCLUSIONS: Therefore, by using CRM, it is possible to discern details in the progression of EBV infection in nasopharyngeal epithelial cells at the molecular level.

Comprehensive analysis of aberrantly expressed circRNAs, mRNAs and lncRNAs in patients with nasopharyngeal carcinoma.

BACKGROUND: The location of nasopharyngeal cancer is hidden, so it is difficult to diagnose at an early stage. In this study, we aimed to investigate the expression profiles of circRNAs, mRNAs and IncRNAs and to provide some basis for further studies. METHODS: Expression profiles of circRNAs, mRNAs, and lncRNAs were analyzed using microarray techniques. The differentially expressed ncRNA was calculated by bioinformatics. RESULTS: A total of 3048 circRNAs, 2179 lncRNAs, and 2015 mRNAs were detected to be significantly differentially expressed in NPC. The most upregulated circRNAs, lncRNAs, and mRNAs were hsa-circ-0067562, NONHSAT232922.1, and HOXB13, respectively. And, the most downregulated circRNAs, lncRNAs, and mRNAs were hsa_circ_0078837, lnc-TTC8-4:3, and LTF, respectively. The number of upregulated DE lncRNAs was more than twice than those downregulated. Our data showed that 80.44% of pairs of lncRNAs and cis-mRNAs demonstrated positive correlations. For lncRNAs and trans-mRNAs pairs, 53.7% of pairs showed positive correlation. LncRNA-mediated cis regulation is a prevalent regulatory mode in the development of nasopharyngeal carcinoma. CR1, LRMP and SORBS2 are predicted to be mediated not only by cis-acting lncRNA modes of action, but also by trans-acting lncRNA mechanisms. Additionally, we constructed a diagnostic prediction model with a high sensitivity and specificity. CONCLUSION: Our study characterized the landscape of circRNAs, mRNAs and lncRNAs in NPC tissue and provided novel insights into the molecular mechanisms of NPC.

Efficacy and Safety of Repetitive Transcranial Magnetic Stimulation for Poststroke Memory Disorder: A Meta-Analysis and Systematic Review.

BACKGROUND: Patients with post-stroke memory disorder (PSMD) have poor quality of life and it is necessary to identify more beneficial stimulation protocols for treatment with repetitive transcranial magnetic stimulation (rTMS). This meta-analysis was conducted to investigate the efficacy and safety of rTMS for improving memory performance, global cognition, and activities of daily living (ADL) among patients with PSMD. METHODS: The PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure, China Science and Technology Journal Database, and Wanfang databases were screened to identify relevant randomized controlled trials. The primary outcome was memory performance; secondary outcomes included global cognition, ADL, and adverse events. STATA software was used to perform data synthesis. RESULTS: Five articles with a total of 192 participants were included. The results indicated that rTMS was superior to control treatments for improving memory performance (mean difference [MD] = 1.73, 95% CI [Confidence Interval] [0.85, 2.60], p < 0.001), global cognition (MD = 2.44, 95% CI [0.96, 3.93], p < 0.001), and ADL (MD = 10.29, 95% CI [5.10, 15.48], p < 0.001). No significant differences were found between the low-frequency (LF) and high-frequency (HF) rTMS subgroups (p = 0.47, I2 = 0.00%) or between the sham rTMS and non-rTMS subgroups (p = 0.94, I2 = 0.00%). Four studies did not reported adverse events. CONCLUSIONS: rTMS may improve memory function, global cognition, and the ability to perform ADL in patients with PSMD. LF-rTMS and HF-rTMS may have equal efficacy for treatment of PSMD. Future studies should consider extending the follow-up period to explore the safety and long-term efficacy of rTMS for treatment of PSMD and the appropriate choice of placebo for clinical trials of this treatment.

An NADPH sensor that regulates cell ferroptosis.

Ferroptosis is a new form of programmed cell death, which achieved great breakthroughs in cell biology during past decade. However, the regulation of ferroptosis is yet to be identified thoroughly. The latest study published on Nature cell biology by Nguyen and colleagues found a new NADPH sensor, MARCHF6 an E3 ubiquitin ligase, mediates ferroptosis in tumor growth and animal development. This finding provides a novel insight into ubiquitin system and energy metabolism in regulation of ferroptosis, which may open up new avenues for tumor treatment.

The expression characteristics and clinical significance of ACP6, a potential target of nitidine chloride, in hepatocellular carcinoma.

BACKGROUND: Acid phosphatase type 6 (ACP6) is a mitochondrial lipid phosphate phosphatase that played a role in regulating lipid metabolism and there is still blank in the clinico-pathological significance and functional roles of ACP6 in human cancers. No investigations have been conducted on ACP6 in hepatocellular carcinoma (HCC) up to date. METHODS: Herein, we appraised the clinico-pathological significance of ACP6 in HCC via organizing expression profiles from globally multi-center microarrays and RNA-seq datasets. The molecular basis of ACP6 in HCC was explored through multidimensional analysis. We also carried out in vitro and in vivo experiment on nude mice to investigate the effect of knocking down ACP6 expression on biological functions of HCC cells, and to evaluate the expression variance of ACP6 in xenograft of HCC tissues before and after the treatment of NC. RESULTS: ACP6 displayed significant overexpression in HCC samples (standard mean difference (SMD) = 0.69, 95% confidence interval (CI) = 0.56-0.83) and up-regulated ACP6 performed well in screening HCC samples from non-cancer liver samples. ACP6 expression was also remarkably correlated with clinical progression and worse overall survival of HCC patients. There were close links between ACP6 expression and immune cells including B cells, CD8 + T cells and naive CD4 + T cells. Co-expressed genes of ACP6 mainly participated in pathways including cytokine-cytokine receptor interaction, glucocorticoid receptor pathway and NABA proteoglycans. The proliferation and migration rate of HCC cells transfected with ACP6 siRNA was significantly suppressed compared with those transfected with negative control siRNA. ACP6 expression was significantly inhibited by nitidine chloride (NC) in xenograft HCC tissues. CONCLUSIONS: ACP6 expression may serve as novel clinical biomarker indicating the clinical development of HCC and ACP6 might be potential target of anti-cancer effect by NC in HCC.

Nickel/Photoredox-Catalyzed Enantioselective Reductive Cross-Coupling between Vinyl Bromides and Benzyl Chlorides.

A visible-light-promoted nickel/photoredox-catalyzed reductive cross-coupling reaction between vinyl bromides and benzyl chlorides is reported. A diverse array of enantioenriched allylic centers containing products could be achieved in good yields (up to 90%) and high enantioselectivities (up to 95% ee). The mechanistic studies show that this reductive cross-coupling involves a radical pathway.

One-Pot Rapid Access to Benzyl Silanes, Germanes, and Stannanes from Toluenes Mediated by a LiN(SiMe3)2/CsCl System.

Organo-silanes, germanes, and stannanes are considered to be conducive to the development of cross-coupling reactions because they are stable, nontoxic, and easy to handle. Using feedstock toluenes, one-pot direct benzylic C-H silylations, germylations, and stannylations are developed. Simply combining toluenes, LiN(SiMe3)2/CsCl, and R3MCl (M = Si, Ge, Sn) generates a diverse array of bench-stable benzyl silanes, germanes, and stannanes (38 examples, 53-90% yields). The syntheses developed here are easy to access on scale.

Benzylic Aroylation of Toluenes Mediated by a LiN(SiMe3)2/Cs+ System.

Chemoselective deprotonative functionalization of benzylic C-H bonds is challenging, because the arene ring contains multiple aromatic C(sp2)-H bonds, which can be competitively deprotonated and lead to selectivity issues. Recently it was found that bimetallic [MN(SiMe3)2 M = Li, Na]/Cs+ combinations exhibit excellent benzylic selectivity. Herein, is reported the first deprotonative addition of toluenes to Weinreb amides mediated by LiN(SiMe3)2/CsF for the synthesis of a diverse array of 2-arylacetophenones. Surprisingly, simple methyl benzoates also react with toluenes under similar conditions to form 2-arylacetophenones without double addition to give tertiary alcohol products. This finding greatly increases the practicality and impact of this chemistry. Some challenging substrates with respect to benzylic deprotonations, such as fluoro and methoxy substituted toluenes, are selectively transformed to 2-aryl acetophenones. The value of benzylic deprotonation of 3-fluorotoluene is demonstrated by the synthesis of a key intermediate in the preparation of Polmacoxib.

Nickel-Catalyzed Cross-Electrophile Coupling of 1,2,3-Benzotriazin-4(3H)-ones with Aryl Bromides.

The nickel-catalyzed cross-electrophile coupling of 1,2,3-benzotriazin-4(3H)-ones with aryl bromides to generate a diverse array of ortho-arylated benzamide derivatives has been developed. The reaction displayed good functional group tolerance with Zn as the reductant. The key to this transformation is the ring opening of benzotriazinones, which undergo a denitrogenative process to obtain various benzamide derivatives (29 examples, 42-93% yield). The scalability of this transformation was demonstrated.