Synthesis of -Alkyl Glycosides from Alkyl Bromides and Glycosyl Carboxylic Acids via Ni/Photoredox Dual Catalysis.

-Alkyl glycosides, an important class of C-glycosides, are widely found in various drugs and natural products. The synthesis of -alkyl glycosides has attracted considerable attention. Herein, we developed a Ni/photoredox catalyzed decarboxylative ()-() coupling reaction of stable glycosylcarboxylic acids with simple aliphatic bromides to generate C-alkyl glycosides.

Ruthenium-Catalyzed Difunctionalization of Vinyl Cyclopropanes for Double -C(sp)-H/C-5(sp)-H Functionalization.

With in-depth research on 1,2-difunctionalization, remote difunctionalization has garnered widespread attention for achieving multifunctionality. Herein, we report a strategy for achieving remote difunctionalization under mild conditions. This strategy exhibited good substrate suitability and functional group tolerance.

Stereoselective assembly of C-oligosaccharides via modular difunctionalization of glycals.

C-oligosaccharides are found in natural products and drug molecules. Despite the considerable progress made during the last decades, modular and stereoselective synthesis of C-oligosaccharides continues to be challenging and underdeveloped compared to the synthesis technology of O-oligosaccharides. Herein, we design a distinct strategy for the stereoselective and efficient synthesis of C-oligosaccharides via palladium-catalyzed nondirected C1-H glycosylation/C2-alkenylation, cyanation, and alkynylation of 2-iodoglycals with glycosyl chloride donors while realizing the difunctionalization of 2-iodoglycals.

A Practical and Regioselective Strategy for Aromatic C-H Difunctionalization via Site-Selective C-H Thianthrenation.

Herein, we present a novel Catellani-type reaction that employed aryl-thianthrenium salts as aryl substrates to trigger the subsequent palladium/norbornene cooperatively catalyzed progress. This strategy can achieve site-selective C-H difunctionalization of aryl compounds without directing groups or a known initiating reagent. A series of functionalized syntheses of bioactive molecules further demonstrated the potential of this strategy.

Copper-Catalyzed Selective Three-Component 1,2-Phosphonoazidation of 1,3-Dienes.

We report a copper-catalyzed selective 1,2-phosphonoazidation of conjugated dienes. This three-component reaction is achieved by using readily available P(O)-H compounds and bench-stable NaN. Salient features of this strategy include its mild reaction conditions, broad functional group tolerance, and high chemoselectivity and regioselectivity.

Visible-Light-Mediated Synthesis of -Alkyl Glycosides via Glycosyl Radical Addition and Aryl Migration.

A visible-light-induced glycoarylation of activated olefins has been accomplished. Glycosyl radicals are generated via radical transfer strategies between (TMS)SiOH and glycosyl bromides. Subsequent radical translocation and rapid 1,4-aryl migration form β-sugar amide derivatives, and eight types of sugars are compatible with this reaction.

Stereoselective Synthesis of Multisubstituted Alkenes via Ruthenium-Catalyzed Remote Migration Arylation of Nonactivated Olefins.

Polysubstituted alkenes are an important class of organic intermediates that widely exist in various natural products and drug molecules. Herein, we reported a stereoselective synthesis of multisubstituted alkenes via ruthenium-catalyzed remote migration arylation of nonactivated olefins. This strategy exhibited wide substrate suitability and excellent functional group tolerance.

Photoredox-Catalyzed N-Directed Regioselective Difluoroalkylation of Unactivated C(sp)-H Bonds.

We report a redox-neutral, visible-light-mediated difluoroalkylation of unactivated C(sp)-H bonds in amides via nitrogen-centered radicals triggered intramolecular hydrogen atom transfer. Notably, all types (tertiary, secondary, and primary) of γ-C(sp)-H bonds displayed excellent reactivity. This methodology presents a facile route for the regioselective introduction of α,α-difluoroketone fragments into organic molecules.

Aryl-to-Vinyl 1,4-Nickel Migration/Reductive Cross-Coupling Reaction for the Stereoselective Synthesis of Multisubstituted Olefins.

The 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.

Naoxintong Capsule for Secondary Prevention of Ischemic Stroke: A Multicenter, Randomized, and Placebo-Controlled Trial.

Objective: To examine whether the combination of Naoxintong Capsule with standard care could further reduce the recurrence of ischemic stroke without increasing the risk of severe bleeding.

Methods: A total of 23 Chinese medical centers participated in this trial. Adult patients with a history of ischemic stroke were randomly assigned in a 1:1 ratio using a block design to receive either Naoxintong Capsule (1.

Enantioselective Synthesis of Both Axially and Planar Chiral Ferrocenes via Axial-to-Planar Diastereoinduction.

Ferrocenes with planar chirality have emerged as an important class of scaffolds for ligands in asymmetric catalysis; however, ferrocene molecules with polychiral structures have not been well explored. Herein, both axially and planar chiral ferrocenes were synthesized via palladium/chiral norbornene cooperative catalysis and axial-to-planar diastereoinduction. In this work, chiral norbornene was used to stereoselectively control the aromatic axial chirality, and further selectivity induced C(sp)-H activation for ferrocene planar chirality.

C-H Hydroxyalkylation or Methylation of Aryl Iodides by Ethers and TMSI via a Catellani Strategy.

In this paper, in the presence of trimethylsilyl iodide, the direct -C-H hydroxyalkylation/methylation of aryl iodines was effectively realized via palladium/norbornene cooperative catalysis when low-cost tetrahydrofuran and 1,2-dimethoxyethane were used as alkyl sources. Heck, Suzuki, and Sonogashira coupling and hydrogenation were all compatible with the reaction as termination steps. In addition, neuromuscular agents and cardiovascular agents were synthesized in one step by this method, showing their potential application value.

Visible-Light-Induced C-F and C-N Bond Cleavage for the Synthesis of -Difluoroalkenes.

Herein, we describe a novel and efficient photoredox catalytic radical addition/defluoroalkylation coupling reaction between primary amines and trifluoromethyl-substituted alkenes. A series of -difluoroalkenes were synthesized via C-N bond cleavage of α-3°, α-2°, and α-1° amines under visible light irradiation. This reaction is characterized by a broad substrate scope and good functional group tolerance.

Copper-Catalyzed Hydrogen Atom Transfer and Aryl Migration Strategy for the Arylalkylation of Activated Alkenes.

Herein, we describe the copper-catalyzed arylalkylation of activated alkenes via hydrogen-atom transfer and aryl migration strategy. The reaction was carried out through a radical-mediated continuous migration pathway using -fluorosulfonamides as the alkyl source. The primary, secondary, and tertiary alkyl radicals formed by intramolecular hydrogen-atom transfer proceeded smoothly.

Ruthenium-Catalyzed Stereo- and Site-Selective ortho- and meta-C-H Glycosylation and Mechanistic Studies.

C-aryl glycosides are popular basic skeletons in biochemistry and pharmaceutical chemistry. Herein, ruthenium-catalyzed highly stereo- and site-selective ortho- and meta-C -H glycosylation is described. A series of C-aryl pyranosides and furanosides were synthesized by this method.

Site-selective coupling of remote C(sp)-H/-C(sp)-H bonds enabled by Ru/photoredox dual catalysis and mechanistic studies.

Construction 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.

Three-Component Ru-Catalyzed Regioselective Alkylarylation of Vinylarenes via -Selective C(sp)-H Bond Functionalization.

We 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.

Profile and dynamics of infectious diseases: a population-based observational study using multi-source big data.

Background: The current surveillance system only focuses on notifiable infectious diseases in China. The arrival of the big-data era provides us a chance to elaborate on the full spectrum of infectious diseases.

Methods: In this population-based observational study, we used multiple health-related data extracted from the Shandong Multi-Center Healthcare Big Data Platform from January 2013 to June 2017 to estimate the incidence density and describe the epidemiological characteristics and dynamics of various infectious diseases in a population of 3,987,573 individuals in Shandong province, China.

One-Pot Stereoselective Synthesis of 2,3-Diglycosylindoles and Tryptophan-C-glycosides via Palladium-Catalyzed C-H Glycosylation of Indole and Tryptophan.

We described a novel palladium-catalyzed C-H glycosylation of indole or tryptophan for a one-pot stereoselective synthesis of 2,3-diglycosylindoles and tryptophan-C-glycosides. In this strategy, the use of air and base-free and ligand-free conditions provided a highly efficient route to construct C-glycosides. The method can be applied to a wide range of cost-effective and convenient glycosyl chloride donors.

Ni-Catalyzed Remote Radical/Cross-Electrophile Coupling Cascade for Selective C(sp)-H Arylation.

An innovative 1,5-HAT cascade strategy has been advanced for the nickel-catalyzed distal arylation via cross-electrophile coupling. Through specific migration, the remote C(sp)-H bond is regioselectively activated, and Ar-I as the available electrophile is used for the construction of the C(sp)-C(sp) bond. This method also has broad applicability for benzylic and aliphatic -fluorocarboxamides with yields up to 80%.

Nickel-Catalyzed Reductive C(sp )-Si Coupling of Chlorohydrosilanes via Si-Cl Cleavage.

We report here a new method for the synthesis of organohydrosilanes from phenols and ketones. This method is established through reductive C-Si coupling of chlorohydrosilanes via unconventional Si-Cl cleavage. The reaction offers access to aryl- and alkenylhydrosilanes with a scope that is complementary to those of the established methods.

Copper-Catalyzed Aminoarylation of Alkenes via Aminyl Radical Addition and Aryl Migration.

We describe a new strategy for aminoarylation of alkenes by copper-catalyzed smiles rearrangement using -benzoylhydroxylamines as the amine reagent. This method affords various β-amino amide derivatives possessing a quaternary carbon center with wide functional group tolerance and high regioselectivity. The mechanistic studies indicate that the transformation can involve aminyl radical intermediates under acid-free condition.

Reductive Alkylation of Alkenyl Acetates with Alkyl Bromides by Nickel Catalysis.

Catalytic alkylation of stable alkenyl C-O electrophiles is synthetically appealing, but studies to date have typically focused on the reactions with alkyl Grignard reagents. We report herein a cross-electrophile reaction of alkenyl acetates with alkyl bromides. This work has enabled a new method for the synthesis of aliphatic alkenes from alkenyl acetates to be established that can be used to add more structural complexity and molecular diversity with enhanced functionality tolerance.

Copper-Catalyzed Direct Allenylation of Inactive Cyclic Ethers.

We report here a direct allenylation reaction of inactive cyclic ethers. The reaction proceeds through a copper-catalyzed 1,4-difunctionalization of 1,3-enynes, with cyano group installed at the allenes simultaneously. This methodology shows a broad functional group compatibility to 1,3-enynes.

Photoredox-catalyzed redox-neutral difluoroalkylation to construct perfluoroketones with difluoroenoxysilanes.

A 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.