Publications by authors named "Kaifan Zhang"

A photoinduced copper-catalyzed strategy for the monofluoroalkylation of alkynes with readily available monofluoroalkyl triflates was developed. It provides a new protocol to access valuable propargyl fluoride compounds via C-C bond formation by avoiding the use of highly toxic fluorination reagents. This reaction proceeded under mild conditions to afford propargyl monofluorides in moderate to high yields.

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Closure of the neural tube represents a highly complex and coordinated process, the failure of which constitutes common birth defects. The serine/threonine kinase p21-activated kinase 2 (PAK2) is a critical regulator of cytoskeleton dynamics; however, its role in the neurulation and pathogenesis of neural tube defects (NTDs) remains unclear. Here, the results show that Pak2 mouse embryos fail to develop dorsolateral hinge points (DLHPs) and exhibit craniorachischisis, a severe phenotype of NTDs.

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Article Synopsis
  • Radical relay presents a new method for C-H activation using mild conditions, addressing issues of harshness in traditional approaches while selectively cleaving inert C(sp)-H bonds to create azidotrifluoromethylated compounds.
  • The process utilizes hydrogen atom transfer (HAT) and an alkene precursor to efficiently generate C-centered radicals, achieving high regioselectivity (>20:1) in reactions.
  • Iron plays a crucial role in the reaction by acting as both a radical initiator and terminator, enabling the incorporation of the azide group, leading to the potential for rapid synthesis of CF-containing organic azides and other valuable compounds for applications like fluorescent tags.
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Background: Intratumor heterogeneity (ITH) has been shown to be inversely associated with immune infiltration in several cancers including clear cell renal cell carcinoma (ccRCC), but it remains unclear whether ITH is associated with response to immunotherapy (e.g. PD-1 blockade) in ccRCC.

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The serine/threonine p21-activated kinases (PAKs), as main effectors of the Rho GTPases Cdc42 and Rac, represent a group of important molecular switches linking the complex cytoskeletal networks to broad neural activity. PAKs show wide expression in the brain, but they differ in specific cell types, brain regions, and developmental stages. PAKs play an essential and differential role in controlling neural cytoskeletal remodeling and are related to the development and fate of neurons as well as the structural and functional plasticity of dendritic spines.

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A mild and efficient nickel-catalyzed direct monofluoromethylation of (hetero)aryl bromides by reductive cross-coupling has been developed. This method exhibits good efficiency, wide functional-group compatibility, and suitability for aryl and heteroaryl bromides with abundant industrial raw material BrCHF. This strategy provides an efficient way to synthesize monofluoromethylated molecules for drug discovery.

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A nickel-catalyzed 1,4-carbofluoroalkylation of 1,3-enynes to access structurally diverse fluoroalkylated allenes has been established. This method has demonstrated high catalytic reactivity, mild reaction conditions, broad substrate scope, and excellent functional-group tolerance. The key to success is the use of a nickel catalyst to generate different fluoroalkyl radicals from readily available and structurally diverse fluoroalkyl halides to access 1,4-difunctionalization of 1,3-enynes by a radical relay.

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A combinatorial nickel-catalyzed monofluoroalkylation of aryl halides with unactivated fluoroalkyl halides by reductive cross-coupling has been developed. This method demonstrated high efficiency, mild conditions, and excellent functional-group tolerance, thus enabling the late-stage monofluoroalkylation of diverse drugs. The key to success was the combination of diverse readily available bidentate and monodentate pyridine-type nitrogen ligands with nickel, which in situ generated a variety of readily tunable catalysts to promote fluoroalkylation with broad scope with respect to both coupling partners.

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A formal [3 + 3] cycloaddition reaction between azides and in situ formed azaoxyallyl cations has been realized. This reaction provided an efficient and practical pathway to synthesize 1,2,3,4-tetrazines in good yields under mild conditions. Biologically active molecules could also be well compatible, highlighting the potential value of this reaction.

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A novel [3 + 3] cycloaddition between in situ formed azaoxyallyl cations and 2-alkenylindoles has been developed. This concise method allows the efficient construction of a series of tetrahydro-β-carbolinones in good yields under mild conditions. Gram-scale experiments and further derivatization of tetrahydro-β-carbolinones highlighted the potential utility of our method.

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The cooperative palladium/l-proline-catalyzed direct α-allylic alkylation of ketones with alkynes is achieved. This reaction exhibits high atom economy since a leaving group is not liberated and a stoichiometric amount of extra oxidant is not needed. A broad range of functional groups are tolerated, and the reaction scope could be further expanded to aldehydes.

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A novel [3 + 2] cycloaddition reaction between in situ formed azaoxyallyl cations and aldehydes has been developed. This concise method allows the rapid formation of a number of oxazolidin-4-ones in high yields with good functional group tolerance at room temperature. Further transformation and late-stage modifications of drug molecules could also be achieved in good yields, highlighting the potential utility of the reaction.

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Cu(i)-Catalyzed oxidative homo-coupling of thiazoline-4-carboxylates with good functional group tolerance has been developed. The methodology presented an efficient method to directly construct vicinal carbon-hetero quaternary centers existing in numerous functional molecules and could be applied to the synthesis of 4,4'-bithiazoles which are difficult to prepare by direct C-H activation.

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Reported herein is a Rh-catalyzed redox-neutral annulation of primary benzamides with diazo compounds, representing an efficient and economic protocol to isoquinolinones. The procedure exhibited good functional group tolerability, scalability, and regioselectivity, obviating the need for oxidants, and only environmentally benign N2 and H2O were released. Further utilization of the method provided an alternative route to functionalized isoquinolines.

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Background: Compelling evidence suggests that SIRT1, NAD(+)-dependent class III protein deacetylase, plays an important role in the prevention and treatment of atherosclerosis by counteracting inflammation. Cluster of differentiation 40 (CD40), as a pro-inflammatory cytokine, has been shown to participate in the pathophysiology of atherosclerosis. The relationship between SIRT1 and CD40, however, remained elusive.

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Sirtuin1 (SIRT1), a NAD(+)-dependent deacetylase, not only regulates lipid and glucose homeostasis, but also involves the regulation of proinflammatory cytokine involved in inflammation-associated diseases. The activation of CD40 triggers inflammation that plays a crucial role in the development of many chronic inflammatory diseases including obesity. Growing evidence indicated that SIRT1 exerts anti-inflammatory properties by suppressing proinflammatory cytokines production.

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Accumulating evidence has suggested the importance of hypoxia in the initiation and development of atherosclerotic lesion, and hypoxia has a profound impact on endothelial cell properties during cardiovascular disease processes. Paeoniflorin, isolated from the root of Paeonia lactiflora pall, can protect endothelial cells from hypoxic damage in a variety of ways, such as by enhancing the production of nitric oxide (NO) and decreasing the expressions of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). This study evaluated the protective effects of paeoniflorin against cobalt chloride (CoCl2, a hypoxia-mimicking agent)-induced apoptosis of endothelial cells (CRL-1730) and the underlying mechanisms in vitro.

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Ethnopharmacological Relevance: Buyang Huanwu Decoction (BYHWD), a traditional Chinese medicine (TCM) formula, has been recognized as a clinical treatment for coronary heart disease (CHD) with qi deficiency and blood stasis syndrome. The effects of BYHWD on hemorheological disorders and energy metabolism in CHD with qi deficiency and blood stasis syndrome are still unclear.

Aim Of The Study: To investigate whether the ameliorative effects of BYHWD on CHD rats with qi deficiency and blood stasis syndrome are associated with the regulation of hemorheological disorders and energy metabolism.

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1. Chronic heart failure (CHF) is often accompanied by renal dysfunction. Exercise training may relieve the symptomatic burden and improve the overall prognosis of CHF.

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