查看更多>>摘要：Eight rare capnosane-type cembranoids,sarcocinerenoids A-H(1-8)and two new cage-type cembranoids sarcocinerenoids I-J(9-10)were isolated from the soft coral Sarcophyton cinereum.The 5/11 bicyclic carbon skeleton is the same in Sarcocinerenoids A-H(1-8),and they collocate distinctive oxygen rings.Sarcocinerenoids I-J(9-10)with a cage-type structure have been discov-ered to have an oxygen bridge and an uncommon seven-membered ring.Extensive spectroscopic investigation,X-ray diffraction analysis,estimated ECD,and DP4+probability assessments were used to ascertain the structures of the two types of diterpenoids.Moreover,compounds 1,4 showed promoting angiogenesis activity in zebrafish assays.
查看更多>>摘要：Herein,we report nickel-catalyzed cross-coupling of gem-difluorinated cyclopropanes with boronic acids,providing the corresponding arylated 2-fluoroallylic scaffolds.This approach used commercially available phosphine ligand Xantphos to obtain monofluorinated al-kenes with high regioselectivity and Z-stereoselectivity Mechanistic studies proposed a Ni(Ⅱ)-fluoroallyl pathway and excluded the radical pathway.Meanwhile,DFT study of the reductive elimination clarified the origin of the high linear selectivity.
查看更多>>摘要：The Pd-catalyzed dipolar cycloaddition represents a significant synthetic strategy for the construction of useful heterocyclic com-pounds.This study developed the dipolar[4+2]and[6+2]cycloaddition reactions of benzo[d]isothiazole 1,1-dioxides(BDs)leading to the synthesis of BD-fused 1,3-oxazinane and 1,3-oxazocane derivatives,respectively.In particular,the synthesis of BD-fused 1,3-oxazinanes demonstrated regio-and enantioselective characteristics,resulting in products with good yields,enantioselectivity and regioselectivity(if applicable).Furthermore,the[6+2]cycloaddition reaction developed in this work represented the first strategy for the synthesis of medium-sized ring compounds based on BDs.
查看更多>>摘要：Metal nanoparticles(NPs)decorated block copolymer(BCP)hybrid nanoparticles have attracted enormous attention for their actual value in catalysis,medical therapy,and bioengineering.The confined assembly of BCPs within evaporative emulsion droplet is verified as an effective method to provide polymeric scaffolds to load metal NPs.However,to date,it remains challenging to generate different types of metal NPs decorated BCP hybrid nanoparticles.Herein,we employed the emulsion confined self-assembly of poly(styrene-b-2-vinylpyridine)(PS-b-P2VP)and the followed seed-mediated growth of Au and palladium(Pd)NPs onto well-defined BCP particles to design a series of Au/Pd decorated BCP hybrid nanoparticles,which exhibited excellent catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol with the reductant of NaBH4.This work may inspire more researchers to investigate the selective decoration of different metal NPs onto the polymeric scaffolds,broadening the potential applications of the inorganic/organic hybrid nanoparticles.
查看更多>>摘要：Valbenazine(Ingrezza),a potent and highly selective inhibitor of vesicular monoamine transporter type 2(VMAT2)through the active metabolite hydrotetrabenazine(HTBZ),has been approved for the treatment of tardive dyskinesia and,very recently,for chorea,which is associated with Huntington's disease.Despite numerous synthetic efforts dedicated to the synthesis of HTBZ,the industrial preparation of valbenazine uses dihydroisoquinoline as a starting material and the chiral resolution of racemic HTBZ derived from ke-tone reduction.Herein,we present a practical synthesis of HTBZ and valbenazine featuring a highly stereoselective 1,3-dipolar cy-cloaddition and enzymatic kinetic resolution.The cascade process includes cycloaddition,N-O bond cleavage,and lactamization,which proved to be operationally simple.The allure of the enzymatic resolution developed in this work offers a rapid access toward affording tetrahydroisoquinoline(THIQ)-fused piperidine in the production of medically significant compounds,such as yohimbine and reserpine.
查看更多>>摘要：A convenient approach for the construction of 2-aminobenzothiazoles via I2-catalyzed tandem cyclization reaction of amines and car-bon disulfide has been developed.The present approach starts from simple and readily available starting materials,affording a series of 2-aminobenzothiazoles in up to 89％yields under metal-free conditions.In this work,C-H/N-H functionalization was achieved and multiple C-hetero bonds were successfully constructed in one pot.
查看更多>>摘要：The asymmetric partial reduction of 1,3-diketones stands as a straightforward pathway to access optically active β-hydroxyketones.In this paper,an asymmetric Piers-type hydrosilylation of 2,2-difluoro-1,3-diketones was successfully realized by using a frustrated Lewis pair of chiral borane and tricyclohexylphosphine as a catalyst,delivering a variety of α,α-difluoro-β-hydroxyketones in high yields with up to 99％ee.Significantly,no over-reduced diol products were observed even with an excess amount of silanes.The product can be conveniently converted to α,α-difluoro-β-hydroxyester or 1,3-anti-diol via an oxidation with m-CPBA or a reduction with DIBAL-H without obvious loss of ee.
查看更多>>摘要：Autophagy is a multi-step cell metabolism process in which cells remove damaged and unwanted materials.During autophagy,au-tophagosomes fuse with lysosomes to form autophagosomes.Autophagosomal membrane components are recycled from autolyso-somes through the autophagosomal components recycling(ACR),while lysosomal components circulate on the autolysosomal sur-face through the autophagic lysosome reformation(ALR)process.Autolysosomes contain components from autophagosomes and lysosomes.However,whether there is a fusion between autolysosome and autophagosome or lysosome at the organelle level re-mains unknown.In this study,a pH and viscosity dual-controlled mitochondria-targeting fluorescent probe Mito-Q was designed based on an asymmetric norcyanine to achieve the high-contrast imaging of mitochondria-containing autolysosomes.Mito-Q not only effectively detected mitochondrial viscosity changes and mitophagy with high sensitivity,but more importantly,the fusion of mitochondria-containing autolysosomes and autophagosomes(FMAA)was observed during autophagy by the real-time confocal im-aging of HeLa cells.
查看更多>>摘要：In nature,fishes have evolved functional skins with effective hydrodynamic performance and anti-fouling,facilitating predation and escaping from predators.Although a large number offish scale-inspired structured surfaces have been explored,the incorporation of mucus on the structured surfaces has been largely ignored.Inspired by the skin of Osteichthyes fishes,a Janus hydrogel coating(JHC)is successfully prepared by a two-step UV light irradiation at room temperature.The bottom side of JHC(STH)achieves a shear adhe-sive strength of 103.3±17.5 kPa and can strongly adhere to a large variety of surfaces,including metals,ceramic and polymers.The top surface of JHC(SLH)replicates the structure of cycloid scales,while the nature of hydrogel mimics the mucus on fish skin.SLH possesses prominent mechanical,anti-swelling,anti-fouling and drag reduction properties.The design strategy for JHC has potential applications in numerous fields,like,pipeline transportation,bioengineering,and shipping industry.
查看更多>>摘要：The azepine ring is a prominent structural scaffold in biologically significant molecules.In this study,we present a Ni(Ⅱ)-catalyzed asymmetric difunctionalization of alkynes,involving intermolecular regioselective arylation and intramolecular nitrile addition,ena-bling the synthesis of enantioenriched azepine derivatives.This reaction simultaneously installs an all-carbon quaternary stereocenter and introduces an unprotected imine functionality,showing great promise for subsequent transformations.The reaction exhibits good tolerance toward various functional groups,resulting in high yields and enantioselectivities.The synthetic utility of this meth-odology is further demonstrated through gram-scale synthesis and product derivatization.This research offers an efficient approach to the synthesis of seven-membered nitrogen heterocycles.
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