Transition-metal-catalyzed hydroarylation of unactivated alkenes metal hydride hydrogen atom transfer (MHAT) is an attractive approach for the construction of C(sp)-C(sp) bonds. However, this kind of reaction focuses mainly on using reductive hydrosilane as a hydrogen donor. Here, a novel photoinduced Co/Ni-cocatalyzed Markovnikov hydroarylation of unactivated alkenes with aryl bromides using protons as a hydrogen source has been developed.
View Article and Find Full Text PDFWe herein reported a novel photoredox-catalyzed three-component alkylarylation of vinyl arenes with alkylboronic pinacol esters (APEs) and cyanoarenes via radical addition/cross-coupling to construct 1,1-diarylalkanes. In this transformation, alkyl radicals were easily available by visible-light-induced oxidative N-H cleavage of morpholine, which used APEs as a radical precursor. Furthermore, this protocol exhibited a broad substrate scope, enabling various styrenes, APEs, and cyanoarenes, as well as bioactive molecule derivatives.
View Article and Find Full Text PDFThe aryl-to-vinyl nickel 1,4-migration (1,4-Ni migration) reaction has been reported for the first time. The generated alkenyl Ni species undergo a reductive coupling reaction with unactivated brominated alkanes affording a series of trisubstituted olefins. This tandem reaction exhibits mild conditions, a broad substrate scope, high regioselectivity, and excellent Z/E stereoselectivity.
View Article and Find Full Text PDFChromodomain-helicase-DNA-binding protein 1 (CHD1) deletion is among the most common mutations in prostate cancer (PCa), but its role remains unclear. In this study, RNA sequencing was conducted in PCa cells after clustered regularly interspaced palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9)-based CHD1 knockout. Gene set enrichment analysis (GSEA) indicated upregulation of hypoxia-related pathways.
View Article and Find Full Text PDFThe annulation reactions of benzoamidyl radicals with alkenes were realized under visible light irradiation with -Ir(ppy) as catalyst and -aminopyridinium salts as benzoamidyl radical precursors. The reaction can deliver two distinct types of products: in the case of vinyl arenes, [3 + 2] annulation product dihydrooxazoles were yielded exclusively; when alkyl-substituted alkenes were used, on the other hand, it afforded [4 + 2] annulation product dihydroisoquinolinones. Factors determining the reaction consequence were elucidated by DFT calculations.
View Article and Find Full Text PDFConstruction of C(sp)-C(sp) bonds regioselective coupling of C(sp)-H/C(sp)-H bonds is challenging due to the low reactivity and regioselectivity of C-H bonds. Here, a novel photoinduced Ru/photocatalyst-cocatalyzed regioselective cross-dehydrogenative coupling of dual remote C-H bonds, including inert γ-C(sp)-H bonds in amides and -C(sp)-H bonds in arenes, to construct -alkylated arenes has been accomplished. This metallaphotoredox-enabled site-selective coupling between remote inert C(sp)-H bonds and -C(sp)-H bonds is characterized by its unique site-selectivity, redox-neutral conditions, broad substrate scope and wide use of late-stage functionalization of bioactive molecules.
View Article and Find Full Text PDFWe report a novel Ru-catalyzed regioselective alkylarylation of vinylarenes with alkyl halides and arenes via -C(sp)-H bond functionalization to construct 1,1-diarylalkanes that generally show bioactivity. In this transformation, a wide spectrum of primary, secondary, and tertiary alkyl halides and electronically varied arenes was well-tolerated. This reaction is characterized by its exquisite regioselectivity of vinylarenes, unique -C(sp)-H selectivity, and redox-neutral conditions.
View Article and Find Full Text PDFA mild and facile approach to construct various perfluoroketones photo-catalyzed difluoroalkylation of difluoroenoxysilanes is developed. The reaction includes a strategy of combination of two fluorine-containing functional groups, which confers the reaction with characteristics like high efficiency, mild conditions, and broad scope. A variety of fluoroalkyl halides including perfluoroalkyl iodides, bromo difluoro esters and amides can be employed as radical precursors.
View Article and Find Full Text PDFA novel dehydrogenative coupling reaction of -fluorocarboxamides with polyfluoroarenes forming C(sp)-C(sp) bonds enabled by copper catalysis has been accomplished. -Fluorocarboxamides are postulated to undergo copper-mediated dehydrogenative cross-coupling reaction with electron-deficient polyfluoroarenes via a radical pathway. Benzylic C-H bonds and aliphatic C-H bonds in -fluorocarboxamides could proceed smoothly and demonstrated excellent regioselectivity.
View Article and Find Full Text PDFA copper-catalyzed radical cross-coupling of oxime esters and activated alkenes is accomplished for the synthesis of cyanoalkylsulfonylated oxindoles and cyanoalkyl amides via an aryl migration strategy. Specifically, the subsequent mechanism research indicates that the unique desulfonylation and sulfone addition processes were involved in the transformation. This transformation is identified as having good functional group applicability with two different quaternary stereocenter in a regioselective manner, which is controlled by the substituent group of the nitrogen.
View Article and Find Full Text PDFA photocatalytic decarboxylative radical addition bifunctionalization cascade for the synthesis of functionalized alcohols is described. The catalytic cycle is completed through single-electron transfer. The advantages of this reaction are the commercially available materials, wide functional group compatibility, and mild conditions.
View Article and Find Full Text PDFDifunctionalization of alkenes is a valuable tool for the synthesis of complicated compounds from simple precursors. Herein, a feasible method for the construction of β-trifluoromethyl-α-substituted alcohols under visible-light-induced metal-free conditions is described. This catalytic system exhibits mild reaction conditions and good compatibility of functional groups.
View Article and Find Full Text PDFA novel visible-light-induced palladium-catalyzed Heck reaction for bromine sugars and aryl olefins with high regio- and stereochemistry selectivity for the preparation of glycosyl styrene is described. This reaction takes place in one step at room temperature by using a simple and readily available starting material. This protocol can be scaled up to a wide range of glycosyl bromide donors and aryl olefin substrates.
View Article and Find Full Text PDFThe study aimed to compare effectiveness and safety of thermal ablation and hepatic resection in patients with liver metastases of gastrointestinal stromal tumors (GISTs). A total of 55 patients (27 in the ablation group and 28 in the surgery group) with liver metastases were included. Overall survival (OS) and progression-free survival (PFS) were assessed with Kaplan-Meier's survival estimate curves.
View Article and Find Full Text PDFCell Physiol Biochem
February 2017
Objective: This study aimed to evaluate the protective effects of atorvastatin against myocardial ischemia/reperfusion (I/R) injury in cardiomyocytes and its possible underlying mechanism.
Method: Direct cytotoxic effect of OGD/R on cardiomyocytes with and without atorvastatin pretreatment was evaluated. Effects of atorvastatin on expression of GSK-3β and miR-199a-5p were determined using RT-PCR and Western blot.
To accurately determine background conditions or extract sources and sinks information from the observed atmospheric carbon dioxide (CO2) concentration is crucial for quantitative estimation of regional and global carbon budget and future trends of atmospheric CO2. In this study, the synchronized observed surface winds and carbon monoxide (CO) concentration have been examined to test their effectiveness as filter factors to determine CO2 background conditions at Waliguan site. The results show that the surface winds and CO concentrations can be used as filter factor in winter, but they are not very effective in summer.
View Article and Find Full Text PDFUnlabelled: Early-onset hepatocellular carcinoma (HCC) accounts for 15%-20% of total HCC cases in Asia, and the incidence is increasing. The low frequency of cirrhosis and poor prognosis of early-onset HCC suggests that its mechanisms may differ from late-onset HCC. Although hepatitis B virus (HBV) infection is epidemiologically associated with HCC, the role of HBV in early-onset HCC remains poorly understood.
View Article and Find Full Text PDFThe role of TGF-β-induced epithelial-mesenchymal transition (EMT) in cancer cell dissemination is well established, but the involvement of lncRNAs in TGF-β signaling is still unknown. In this study, we observed that the lncRNA-activated by TGF-β (lncRNA-ATB) was upregulated in hepatocellular carcinoma (HCC) metastases and associated with poor prognosis. lncRNA-ATB upregulated ZEB1 and ZEB2 by competitively binding the miR-200 family and then induced EMT and invasion.
View Article and Find Full Text PDFObjective: To explore the diagnostic value of preoperative enhanced computed tomography (CT) plus vascular endothelial growth factor C (VEGF-C) expression in hilar and mediastinal lymph nodes metastasis of non-small cell lung cancer.
Methods: A total of 87 patients with non-small cell lung cancer (NSCLC) received preoperative chest enhanced CT scans and underwent standard radical operation and systematic lymph node dissection. Pathologic examination was selected as the gold standard to determine lymph node metastasis.
Objective: To investigate the diagnostic accuracy of needle puncture biopsy and pathological examination of frozen during operation for pulmonary nodules, and whether this diagnostic method can replace tumor resection examination.
Methods: Totally 50 patients (28 males and 22 females, average age was 59 years) who had the single nodule after imaging examination without any pathological diagnostic from January to October 2010 were selected in this research work. During open operation or video assisted thoracic surgery, needle (14 G model) was used to puncture biopsy for pathological examination of frozen.
Unlabelled: In recent years, long noncoding RNAs (lncRNAs) have been shown to have critical regulatory roles in cancer biology. However, the contributions of lncRNAs to hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) remain largely unknown. Differentially expressed lncRNAs between HBV-related HCC and paired peritumoral tissues were identified by microarray and validated using quantitative real-time polymerase chain reaction.
View Article and Find Full Text PDFObjective: To investigate the metastatic rate of segmental and/or sub-segmental lymph nodes and their roles in pathological staging after a major pulmonary resection.
Methods: This prospective study recruited 90 cases of pulmonary resection performed at our department from February 2007 to February 2008. Hilar lymph nodes (No.
Hepatitis B virus core protein virus-like particles (HBc-VLPs) act as a strong immunogen and are suitable for uptake by dendritic cells (DCs), in which they directly promote DC maturation and migration. To illustrate the utility of global proteomic analysis techniques in elucidating the molecular events that are altered in HBc-VLP-pulsed bone marrow-derived DCs (BMDCs) and to gain a better understanding of the molecular mechanisms of capture and processing of HBc-VLP-pulsed BMDCs, an antigen (Ag) delivery system based on HBc-VLP-pulsed BMDCs was developed. Two-dimensional electrophoresis (2-DE) and tandem mass spectrometry (MS/MS) analyses were utilized to analyze the differential protein expression patterns between HBc-VLP-pulsed and untreated BMDCs.
View Article and Find Full Text PDFWe here report that miR-17-92 cluster is a novel target for p53-mediated transcriptional repression under hypoxia. We found the expression levels of miR-17-92 cluster were reduced in hypoxia-treated cells containing wild-type p53, but were unchanged in hypoxia-treated p53-deficient cells. The repression of miR-17-92 cluster under hypoxia is independent of c-Myc.
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