An efficient C-glycoside production platform enabled by rationally tuning the chemoselectivity of glycosyltransferases.

Despite the broad potential applications of C-glycosides, facile synthetic methods remain scarce. Transforming glycosyltransferases with promiscuous or natural O-specific chemoselectivity to C-glycosyltransferases is challenging. Here, we employ rational directed evolution of the glycosyltransferase MiCGT to generate MiCGT-QDP and MiCGT-ATD mutants which either enhance C-glycosylation or switch to O-glycosylation, respectively.

Nickel-Catalyzed Cross-Coupling of Aziridines with Thioesters toward Atom-Economic Synthesis of β-Sulfanyl Amides.

Thioesters have been recognized as a class of powerful bifunctional reagents, namely, great donors of acyl and sulfide moieties. However, such application in value-added synthesis is still very limited to date. Herein, a nickel-catalyzed cross-coupling reaction system of aziridines with thioesters was developed under redox-neutral and mild conditions.

Photocatalytic manipulation of Ca signaling for regulating cellular and animal behaviors via MOF-enabled HO generation.

The in situ generation of HO in cells in response to external stimulation has exceptional advantages in modulating intracellular Ca dynamics, including high controllability and biological safety, but has been rarely explored. Here, we develop photocatalyst-based metal-organic frameworks (DCSA-MOFs) to modulate Ca responses in cells, multicellular spheroids, and organs. By virtue of the efficient photocatalytic oxygen reduction to HO without sacrificial agents, photoexcited DCSA-MOFs can rapidly trigger Ca outflow from the endoplasmic reticulum with single-cell precision in a repeatable and controllable manner, enabling the propagation of intercellular Ca waves (ICW) over long distances in two-dimensional and three-dimensional cell cultures.

B(CF)-catalyzed regio- and stereoselective thiosulfonylation of terminal alkynes with thiosulfonates.

Herein, a metal-free main-group catalysis system for thiosulfonylation of terminal alkynes with thiosulfonates has been established by using commercially available B(CF) as a catalyst. The protocol provides a highly regio- and stereoselective route for the synthesis of diverse ()-(β)-arylthiolvinyl sulfones under mild conditions with 100% atom-economy and exceptional functional group compatibility.

Synthesis of -Difluorinated 1,4-Dienes via Nickel-Catalyzed Three-Component Coupling of (Trifluoromethyl)alkenes, Alkynes, and Organoboronic Acids.

Herein, a nickel-catalyzed defluorinative three-component coupling of trifluoromethyl alkenes, internal alkynes, and organoboronic acids is presented. The protocol provides a highly efficient and selective route for the synthesis of structurally diverse -difluorinated 1,4-dienes under mild conditions. Mechanistic studies suggest that C-F bond activation proceeds probably through the oxidative cyclization of trifluoromethyl alkenes with Ni(0) species, sequential addition to alkynes, and β-fluorine elimination.

Nickel-Catalyzed Desulfonylative Reductive Cross-Coupling of Aryl Sulfones with Aryl Bromides.

Herein, a nickel catalysis system for desulfonylative C(sp)-C(sp) reductive cross-coupling reactions of aryl sulfone derivatives with a range of aryl bromides has been established to form diverse biaryl compounds. The complex Ar-Ni(II)-SOCF bearing a phosphine ligand through oxidative addition of aryl sulfone to Ni(0) species was isolated and confirmed by an X-ray, which provides solid evidence for the understanding of the C(Ar)-SO bond activation and reaction mechanism.

C(sp)-C(sp) Reductive Cross-Coupling of Triarylphosphines with Aryl Halides by Palladium/Nickel Co-catalysis.

Herein, we report the first general C(sp)-C(sp) reductive cross-coupling reaction of diverse triarylphosphines with a wide range of aryl halides by palladium/nickel co-catalysis. This protocol offers a unique route for the synthesis of biaryl compounds via the activation of inert C(Ar)-P bonds. The mechanistic studies demonstrate that the formation of the phosphonium salts in situ plays a key role in the catalytic cycle.

Rooted in earth, rooted in community: Aging in rural houses of northern China.

Northern China has experienced unprecedented urbanization over the past several decades, with younger Chinese moving to cities while leaving the lion's share of the older population in rural areas. This study explores how this structural change creates unique opportunities and challenges for older adults living in rural houses, which informs their everyday practices, the meanings of homes, and their subsequent housing choices. We examined the housing experiences of rural older adults through a field study conducted in Heilongjiang province.

Cascade of C(sp)-H Addition to Carbonyl and C(sp)-CN/C(sp)-H Coupling Enabled by Brønsted Acid: Construction of Benzo[]carbazole Frameworks.

Herein, we report an unprecedented cascade reaction of C(sp)-H addition to carbonyl and the C(sp)-CN/C(sp)-H coupling of 2-(2-oxo-2-arylethyl)benzonitriles with indoles enabled by commercially available TsOH·HO. The protocol represents the first metal-free C(sp)-CN/C(sp)-H coupling, affording a new route for the synthesis of various benzo[]carbazole derivatives with a broad substrate scope, high yields, and simple conditions.

A Probe into the Intervention Mechanism of Yiqi Huayu Jiedu Decoction on TLR4/NLRP3 Signal Pathway in Lipopolysaccharide-Induced Acute Respiratory Distress Syndrome (ARDS) Rats.

Background: This study discusses the anti-inflammatory mechanism of Yiqi Huayu Jiedu decoction (YQHYJD) and studies the intervening effect of YQHYJD on the inflammatory cytokines in acute respiratory distress syndrome (ARDS) rats by inhibiting the TLR4/NLRP3 signal pathway. The aim of the probe is to provide evidence to support the identification of therapeutic targets in Chinese medicine treatment, which broadens the alternatives for the treatment of ARDS.

Method: A lipopolysaccharide (LPS)-induced ARDS model group is established on rats by tail vein injection.

Electron-deficient boron-based catalysts for C-H bond functionalisation.

In contrast to transition metal-catalysed C-H functionalisation, highly efficient construction of C-C and C-X (X = N, O, S, B, Si, etc.) bonds through metal-free catalytic C-H functionalisation remains one of the most challenging tasks for synthetic chemists. In recent years, electron-deficient boron-based catalyst systems have exhibited great potential for C-H bond transformations.

Alleviation of Lipopolysaccharide-Induced Acute Respiratory Distress Syndrome in Rats by Yiqi Huayu Jiedu Decoction: A Tandem Mass Tag-Based Proteomics Study.

Background: To study the effect of Yiqi Huayu Jiedu Decoction (YQHYJD) on protein expression in the lung tissue of acute respiratory distress syndrome (ARDS) rats and to explore the underlying molecular therapeutic mechanism of YQHYJD.

Methods: Sprague Dawley rats were administered with YQHYJD by oral gavage for 1 week. The rats were injected with lipopolysaccharide (LPS) to induce ARDS.

Study on Intervention Mechanism of Yiqi Huayu Jiedu Decoction on ARDS Based on Network Pharmacology.

Background: Yiqi Huayu Jiedu (YQHYJD) is a traditional Chinese medicine decoction made up of eight traditional Chinese medicines. Although YQHYJD is effectively used to prevent and treat ARDS/acute lung injury (ALI) in rats, the molecular mechanisms supporting its clinical application remain elusive. The purpose of the current study was to understand its lung protective effects at the molecular level using network pharmacology approach.

Radical C-N Borylation of Aromatic Amines Enabled by a Pyrylium Reagent.

Herein, we report a radical borylation of aromatic amines through a homolytic C(sp )-N bond cleavage. This method capitalizes on a simple and mild activation via a pyrylium reagent ( Pyry-OTf) thus priming the amino group for reactivity. The combination of terpyridine and a diboron reagent triggers a radical reaction which cleaves the C(sp )-N bond and forges a new C(sp )-B bond.

Ni-Catalyzed Reductive Liebeskind-Srogl Alkylation of Heterocycles.

Herein we present a Ni-catalyzed alkylation of C-SMe with alkyl bromides for the decoration of heterocyclic frameworks. The protocol, reminiscent to the Liebeskind-Srogl coupling, makes use of simple C(sp)-SMe to be engaged in a reductive coupling. The reaction is suitable for a preponderance of highly valuable heterocyclic motifs.

B(C F ) /Amine-Catalyzed C(sp)-H Silylation of Terminal Alkynes with Hydrosilanes: Experimental and Theoretical Studies.

Transition metal catalyzed C-H functionalization of organic compounds has proved to be a useful atom-efficient strategy in organic synthesis. In contrast, main-group-element-based catalytic processes for C-H functionalization have remained underexplored to date. Reported herein is the catalytic C(sp)-H silylation of a wide range of terminal alkynes with hydrosilanes by using a combination of B(C F ) and an organic base such as triethylenediamine (DABCO).

Selective Functionalization of Aminoheterocycles by a Pyrylium Salt.

The functionalization of aminoheterocycles by using a pyrylium tetrafluoroborate reagent (Pyry-BF ) is presented. This reagent efficiently condenses with a great variety of heterocyclic amines and primes the C-N bond for nucleophilic aromatic substitution. More than 60 examples for the formation of C-O, C-N, C-S, or C-SO R bonds are disclosed herein.

α-C-H Alkylation of Methyl Sulfides with Alkenes by a Scandium Catalyst.

The C-H addition of sulfides to alkenes is an atom-efficient route for the functionalization and modification of sulfide compounds through C-C bond formation, but this transformation is highly challenging. We report here the regioselective α-C(sp)-H addition of a wide range of methyl sulfides to a variety of olefins and dienes by a half-sandwich scandium catalyst. This protocol provides a unique route for the synthesis of diverse sulfide derivatives through C-C bond formation at a sulfur-adjacent carbon atom in a 100% atom efficient fashion.

B(CF)-Catalyzed C-Si/Si-H Cross-Metathesis of Hydrosilanes.

The substituent redistribution of hydrosilanes on silicon through C-Si and Si-H bond cleavage and reformation is of great interest and importance, but this transformation is usually difficult to achieve in a selective fashion. By using electron-rich aromatic hydrosilanes, we have achieved for the first time the selective C-Si/Si-H bond homo- and cross-metathesis of a series of hydrosilanes in the presence of a boron catalyst B(CF). This protocol features simple reaction conditions, high chemoselectivity, wide substrate scope, and high functionality tolerance, offering a new pathway for the synthesis of multisubstituted functional silanes.

Boron-Catalyzed Aromatic C-H Bond Silylation with Hydrosilanes.

Metal-free catalytic C-H silylation of a series of aromatic compounds such as N,N-disubstituted anilines with various hydrosilanes has been achieved for the first time using commercially available B(C6F5)3 as a catalyst. This protocol features simple and neutral reaction conditions, high regioselectivity, wide substrate scope (up to 40 examples), Si-Cl bond compatibility, and no requirement for a hydrogen acceptor.

Gold-catalyzed cascade C-H/C-H cross-coupling/cyclization/alkynylation: an efficient access to 3-alkynylpyrroles.

An efficient approach to 3-alkynylpyrroles has been developed through the gold-catalyzed reaction of β-enamino derivatives with terminal alkynes, which features complete regiocontrol, relatively wide substrate scope, and high functional group tolerance. Mechanistic studies show that the reaction proceeds through the gold-catalyzed cascade oxidative C-H/C-H cross-coupling, cyclization and alkynylation.

Regioselective decarboxylative direct C-H arylation of boron dipyrromethenes (BODIPYs) at 2,6-positions: a facile access to a diversity-oriented BODIPY library.

A palladium-catalyzed regioselective decarboxylative direct C-H arylation of boron dipyrromethenes (BODIPYs) at the 2,6-positions has been developed as a late-stage approach to rapidly assemble a diversity-oriented BODIPY library. With the complement of this protocol, the direct C-H arylation of BODIPYs becomes regiocontrollable at α- and β-positions. A new type of indole-fused BODIPY exhibiting bright red/NIR fluorescence with a large molar extinction coefficient (145,500 M(-1) cm(-1)) and a high quantum yield (71%) has been synthesized for the first time.

Gold-catalyzed C(sp3)-H/C(sp)H coupling/cyclization/oxidative alkynylation sequence: a powerful strategy for the synthesis of 3-alkynyl polysubstituted furans.

In sharp contrast to the gold-catalyzed reactions of alkynes/allenes with nucleophiles, gold-catalyzed oxidative cross-couplings and especially C-H/C-H cross-coupling have been under represented. By taking advantage of the unique redox property and carbophilic π acidity of gold, this work realizes the first gold-catalyzed direct C(sp(3))-H alkynylation of 1,3-dicarbonyl compounds with terminal alkynes under mild reaction conditions, with subsequent cyclization and in situ oxidative alkynylation. A variety of terminal alkynes including aryl, heteroaryl, alkenyl, alkynyl, alkyl, and cyclopropyl alkynes all successfully participate in the domino reaction.

Silver-catalyzed one-pot cyclization/fluorination of 2-alkynylanilines: highly efficient synthesis of structurally diverse fluorinated indole derivatives.

Highly efficient approaches to obtain structurally diverse fluorinated indole derivatives have been realized through the Ag-catalyzed one-pot cyclization/fluorination of 2-alkynylanilines in the presence of NFSI or Selectfluor.