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The Journal of Organic Chemistry Jun 2024The synthesis of thiazolines, thiazolidines, and thiazolidinones has been extensively studied, due to their biological activity related to neurodegenerative diseases,...
The synthesis of thiazolines, thiazolidines, and thiazolidinones has been extensively studied, due to their biological activity related to neurodegenerative diseases, such as Parkinson's and Alzheimer's, as well as their antiparasitic and antihypertensive properties. The closely related thiazolidin-2-imines have been studied less, and efficient strategies for synthesizing them, mainly based on the reaction of propargylamines with isothiocyanates, have been explored less. The use of one-pot approaches, providing modular, straightforward, and sustainable access to these compounds, has also received very little attention. Herein, we report a novel, one-pot, multicomponent, copper-catalyzed reaction among primary amines, ketones, terminal alkynes, and isothiocyanates, toward thiazolidin-2-imines bearing quaternary carbon centers on the five-membered ring, in good to excellent yields. Density functional theory calculations, combined with experimental mechanistic findings, suggest that the copper(I)-catalyzed reaction between the -formed propargylamines and isothiocyanates proceeds with a lower energy barrier in the pathway leading to the S-cyclized product, compared to that of the N-cyclized one, toward the chemo- and regioselective formation of 5-exo-dig S-cyclized thiazolidin-2-imines.
PubMed: 38725347
DOI: 10.1021/acs.joc.4c00394 -
BioRxiv : the Preprint Server For... Feb 2024Chemical proteomics enables the global assessment of small molecule-protein interactions in native biological systems and has emerged as a versatile approach for ligand...
Chemical proteomics enables the global assessment of small molecule-protein interactions in native biological systems and has emerged as a versatile approach for ligand discovery. The range of small molecules explored by chemical proteomics has, however, been limited. Here, we describe a diversity-oriented synthesis (DOS)-inspired library of stereochemically-defined compounds bearing diazirine and alkyne units for UV light-induced covalent modification and click chemistry enrichment of interacting proteins, respectively. We find that these 'photo-stereoprobes' interact in a stereoselective manner with hundreds of proteins from various structural and functional classes in human cells and demonstrate that these interactions can form the basis for high-throughput screening-compatible nanoBRET assays. Integrated phenotypic analysis and chemical proteomics identified photo-stereoprobes that modulate autophagy by engaging the mitochondrial serine protease CLPP. Our findings show the utility of photo-stereoprobes for expanding the ligandable proteome, furnishing target engagement assays, and discovering and characterizing bioactive small molecules by cell-based screening.
PubMed: 38464067
DOI: 10.1101/2024.02.27.582206 -
Journal of the American Chemical Society Jun 2023The direct coupling of aldehydes with petrochemical feedstock alkenes and alkynes would represent a practical and streamlined approach for allylation and allenylation...
The direct coupling of aldehydes with petrochemical feedstock alkenes and alkynes would represent a practical and streamlined approach for allylation and allenylation chemistry. However, conventional approaches commonly require preactivated substrates or strong bases to generate allylic or propargylic carbanions and only afford branched allylation or propargylation products. Developing a mild and selective approach to access synthetically useful linear allylation and allenylation products is highly desirable, albeit with formidable challenges. We report a strategy using hydrogen evolution reaction (HER) to generate a carbanion from weakly acidic sp C-H bonds (p ∼ 35-40) under mild reaction conditions, obviating the use of strong bases, Schlenk techniques, and multistep procedures. The cathodically generated carbanion the typical reaction selectivity to afford unconventional isomerizing allylation and allenylation products (125 examples). The generation of carbanions was monitored and identified by ultraviolet-visible (UV-vis) spectroelectrochemistry. Furthermore, we extended this protocol to the generation of other carbanions and their application in coupling reactions between alcohols with carbanions. The appealing features of this approach include mild reaction conditions, excellent functional group tolerance, unconventional chemo- and regioselectivity, and the diverse utility of products, which includes offering direct access to diene luminophores and bioactive scaffolds. We also performed cyclic voltammetry, control experiments, and density functional theory (DFT) calculations to rationalize the observed reaction selectivity and mechanism.
PubMed: 37318054
DOI: 10.1021/jacs.3c04864 -
Cancer Science Mar 2024Pancreatic cancer (PC) is a highly aggressive and deadly malignancy with limited treatment options and poor prognosis. Identifying new therapeutic targets and developing...
Pancreatic cancer (PC) is a highly aggressive and deadly malignancy with limited treatment options and poor prognosis. Identifying new therapeutic targets and developing effective strategies for PC treatment is of utmost importance. Here, we revealed that SHCBP1 is significantly overexpressed in PC and negatively correlated with patient prognosis. Knockout of SHCBP1 inhibits the proliferation and migration of PC cells in vitro, and suppresses the tumor growth in vivo. In addition, we identified AZD5582 as a novel inhibitor of SHCBP1, which efficiently restrains the growth of PC in cell lines, organoids, and patient-derived xenografts. Mechanistically, we found that AZD5582 induced the apoptosis of PC cells by inhibiting the activity of PI3K/AKT signaling and preventing the degradation of TP53. Collectively, our study highlights SHCBP1 as a potential therapeutic target and its inhibitor AZD5582 as a viable agent for PC treatment strategies.
Topics: Humans; Phosphatidylinositol 3-Kinases; Prognosis; Signal Transduction; Pancreatic Neoplasms; Cell Line, Tumor; Cell Proliferation; Shc Signaling Adaptor Proteins; Alkynes; Oligopeptides
PubMed: 38151993
DOI: 10.1111/cas.16059 -
The Journal of Organic Chemistry Nov 2023A new fluorinated azidoethane─1-azido-1,1,2,2-tetrafluoroethane─was prepared in quantitative yield by the addition of an azide anion to tetrafluoroethylene in a...
A new fluorinated azidoethane─1-azido-1,1,2,2-tetrafluoroethane─was prepared in quantitative yield by the addition of an azide anion to tetrafluoroethylene in a protic medium. The title azide was shown to be thermally stable and insensitive to impact. Copper(I)-catalyzed [3 + 2] cycloaddition with alkynes afforded 4-substituted -tetrafluoroethyl-1,2,3-triazoles which underwent rhodium(II)-catalyzed transannulation with nitriles to novel -tetrafluoroethylimidazoles or the reaction with triflic acid to enamido triflates. [3 + 2] Cycloaddition of the title azide with primary amines afforded novel 5-difluoromethyl tetrazoles.
PubMed: 37862453
DOI: 10.1021/acs.joc.3c01346 -
Science Advances Apr 2024Ketones are ubiquitous in bioactive natural products, pharmaceuticals, chemical feedstocks, and synthetic intermediates. Hence, deacylative coupling reactions enable the...
Ketones are ubiquitous in bioactive natural products, pharmaceuticals, chemical feedstocks, and synthetic intermediates. Hence, deacylative coupling reactions enable the versatile elaboration of a plethora of chemicals to access complex drug candidates and natural products. Here, we present deacylative arylation and alkynylation strategies for the synthesis of a wide range of alkyl-tethered arenes and alkynes from cyclic ketones and methyl ketones under dual nickel/photoredox catalysis. This reaction begins by generating a pre-aromatic intermediate (PAI) through the condensation of the ketone and '-methylpicolino-hydrazonamide (MPHA), followed by the oxidative cleavage of the PAI α-C─C bond to form an alkyl radical, which is subsequently intercepted by a Ni complex, facilitating the formation of diverse C()-C()/C() bonds with remarkable generality. This protocol features a one-pot reaction capability, high regioselectivity and ring-opening efficiency, mild reaction conditions, and a broad substrate scope with excellent functional group compatibility.
PubMed: 38669332
DOI: 10.1126/sciadv.ado0225 -
ACS Omega Nov 2023Click chemistry is a set of easy, atom-economical reactions that are often utilized to combine two desired chemical entities. Click chemistry accelerates lead... (Review)
Review
Click chemistry is a set of easy, atom-economical reactions that are often utilized to combine two desired chemical entities. Click chemistry accelerates lead identification and optimization, reduces the complexity of chemical synthesis, and delivers extremely high yields without undesirable byproducts. The most well-known click chemistry reaction is the 1,3-dipolar cycloaddition of azides and alkynes to form 1,2,3-triazoles. The resulting 1,2,3-triazoles can serve as both bioisosteres and linkers, leading to an increase in their use in the field of drug discovery. The current Review focuses on the use of click chemistry to identify new molecules for treating neurodegenerative diseases and in other areas such as peptide targeting and the quantification of biomolecules.
PubMed: 38046293
DOI: 10.1021/acsomega.3c04960 -
Microorganisms May 2024Conjugation of carbohydrates to nanomaterials has been extensively studied and recognized as an alternative in the biomedical field. Dendrimers synthesized with mannose...
Conjugation of carbohydrates to nanomaterials has been extensively studied and recognized as an alternative in the biomedical field. Dendrimers synthesized with mannose at the end group and with entrapped zero-valent copper/silver could be a potential candidate against bacterial proliferation. This study is aimed at investigating the bactericidal activity of metal-glycodendrimers. The Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction was used to synthesize a new mannosylated dendrimer containing 12 mannopyranoside residues in the periphery. The enterotoxigenic fimbriae 4 (ETEC:F4) viability, measured at 600 nm, showed the half-inhibitory concentration (IC) of metal-free glycodendrimers (D), copper-loaded glycodendrimers (D:Cu) and silver-loaded glycodendrimers (D:Ag) closed to 4.5 × 10, 3.5 × 10 and to 1.0 × 10 µg/mL, respectively, and minimum inhibitory concentration (MIC) of D, D:Cu and D:Ag of 2.0, 1.5 and 1.0 × 10 µg/mL, respectively. The release of bacteria contents onto broth and the inhibition of ETEC:F4 biofilm formation increased with the number of metallo-glycodendrimer materials, with a special interest in silver-containing nanomaterial, which had the highest activity, suggesting that glycodendrimer-based materials interfered with bacteria-bacteria or bacteria-polystyrene interactions, with bacteria metabolism and can disrupt bacteria cell walls. Our findings identify metal-mannose-dendrimers as potent bactericidal agents and emphasize the effect of entrapped zero-valent metal against ETEC:F4.
PubMed: 38792795
DOI: 10.3390/microorganisms12050966 -
Molecules (Basel, Switzerland) Nov 2023β-halogenated enol esters and ethers are versatile building blocks in organic synthesis, which has attracted increasing attention. In this study, we report the facile...
β-halogenated enol esters and ethers are versatile building blocks in organic synthesis, which has attracted increasing attention. In this study, we report the facile -oxyiodination and oxychlorination of alkynes, leading to the direct construction of versatile halogenated enol esters and ethers. This transformation features an easy operation, optimal atomic economy, a strong functional group tolerance, broad substrate scope, and excellent trans-selectivity. Employing highly electrophilic bifunctional N-X (halogen) reagents was the key to achieving broad reaction generality. To our knowledge, this transformation represents the first oxyhalogenation system employing N-X (halogen) reagents as both oxylation and halogenation sources.
PubMed: 37959838
DOI: 10.3390/molecules28217420 -
BioRxiv : the Preprint Server For... Apr 2024The stimulator of interferon genes (STING) pathway links innate and adaptive antitumor immunity and therefore plays an important role in cancer immune surveillance. This...
The stimulator of interferon genes (STING) pathway links innate and adaptive antitumor immunity and therefore plays an important role in cancer immune surveillance. This has prompted widespread development of STING agonists for cancer immunotherapy, but pharmacological barriers continue to limit the clinical impact of STING agonists and motivate the development of drug delivery systems to improve their efficacy and/or safety. To address this challenge, we developed SAPCon, a STING-activating polymer-drug conjugate platform based on strain-promoted azide-alkyne cycloaddition of dimeric-amidobenzimidazole (diABZI) STING agonists to hydrophilic polymer chains through an enzyme-responsive chemical linker. To synthesize a first-generation SAPCon, we designed a diABZI prodrug modified with a DBCO reactive handle a cathepsin B-cleavable spacer for intracellular drug release and conjugated this to pendant azide groups on a 100 kDa poly(dimethyla acrylamide-co-azide methacrylate) copolymer backbone to increase circulation time and enable passive tumor accumulation. We found that intravenously administered SAPCon accumulated at tumor sites where they it was endocytosed by tumor-associated myeloid cells, resulting in increased STING activation in tumor tissue compared to a free diABZI STING agonist. Consequently, SAPCon promoted an immunogenic tumor microenvironment, characterized by increased frequency of activated macrophages and dendritic cells and improved infiltration of CD8+ T cells, resulting in inhibition of tumor growth, prolonged survival, and increased response to anti-PD-1 immune checkpoint blockade in orthotopic models of breast cancer. Collectively, these studies position SAPCon as a modular and programmable platform for improving the efficacy of systemically administered STING agonists for cancer immunotherapy.
PubMed: 38585879
DOI: 10.1101/2024.03.23.585817