A Skin-Inspired High-Performance Tactile Sensor for Accurate Recognition of Object Softness.

High-performance tactile sensors with skin-sensing properties are crucial for intelligent perception in next-generation smart devices. However, previous studies have mainly focused on the sensitivity and response range of tactile sensation while neglecting the ability to recognize object softness. Therefore, achieving a precise perception of the softness remains a challenge.

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.

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.

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.

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.

Visible-Light-Induced Copper-Catalyzed Asymmetric C(sp)-C(sp)-H Glycosylation: Access to C-Glycopeptides.

Herein, a practical and highly efficient method for visible-light-induced copper-catalyzed -aminoquinoline-directed asymmetric C(sp)-C(sp)-H glycosylation was reported. At the same time, C(sp)-C(sp)-H glycosylation of nondeoxysugars with amino acids to construct C-glycopeptides was achieved. This approach promoted the synthesis of various C-glycopeptides and provided a new model for the synthesis of C-glycoamino acids.

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.

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.

Palladium-catalyzed rearrangement reaction to access 1-phenanthrol derivatives.

This manuscript describes an unusual Pd-catalyzed rearrangement reaction. It provides efficient access to 1-phenanthrol derivatives using allyloxy-tethered aryl iodides. This rearrangement process involves the cleavage of a C-I bond, a C-O bond and C-H bonds, and the formation of two C-C bonds in one-pot.

Palladium-catalyzed C-H glycosylation and retro Diels-Alder tandem reaction structurally modified norbornadienes (smNBDs).

This report describes palladium-catalyzed C-H glycosylation and retro Diels-Alder tandem reaction structurally modified norbornadienes (smNBDs). smNBDs were proposed to regulate the reactivity of the aryl-norbornadiene-palladacycle (ANP), including its high chemoselectivity and regioselectivity, which were the key to constructing C2 and C3 unsubstituted C4-glycosidic indoles. The scope of this substrate is extensive; the halogenated six-membered and five-membered glycosides were applied to the reaction smoothly, and -alkyl (primary, secondary and tertiary) C4-glycosidic indoles can also be obtained by this method.

[Allergen Analysis of 4622 Children with Allergic Diseases in Shaanxi Province].

Objective: To study the distributional characteristics of allergens in children with allergic diseases in Shaanxi province.

Methods: A total of 4 622 children diagnosed with allergic diseases in the Asthma Center, Department of Pediatrics, Xijing Hospital from March 2015 to February 2019 were selected. Serum allergen-specific immunoglobulin E (sIgE) of 19 common kinds of allergens were examined with enzyme-linked immunosorbent assay (ELISA).

Palladium-Catalyzed C-H Amination/[2 + 3] or [2 + 4] Cyclization via C(sp or sp)-H Activation.

This report describes a palladium-catalyzed Catellani reaction consisting of amination/[2 + 3] or [2 + 4] cyclization via a carboxylate ligand-exchange strategy. This method effectively activates -substituents that avoid a second C-H palladation. The scope of substrates was broad, -methyl-substituted iodoarenes were applied to the reaction smoothly, and -phenyl-substituted iodoarenes can also be obtained by this method.

Highly regioselective and stereoselective synthesis of C-Aryl glycosides nickel-catalyzed -C-H glycosylation of 8-aminoquinoline benzamides.

C-Aryl glycosides are of high value as drug candidates. Here a novel and cost-effective nickel catalyzed ortho-CAr-H glycosylation reaction with high regioselectivity and excellent α-selectivity is described. This method shows great functional group compatibility with various glycosides, showing its synthetic potential.

Modular Synthesis of Aryl Thio/Selenoglycosides via the Catellani Strategy.

We described a novel palladium-catalyzed domino procedure for the preparation of (hetero)aryl thio/selenoglycosides. Readily available (hetero)aryl iodides and easily accessible 1-thiosugars/1-selenosugars are utilized as the substrates. Meanwhile, 10 types of sugars are quite compatible with this reaction with good regio- and stereoselectivity, high efficiency, and broad applicability (up to 89%, 53 examples).

Palladium-Catalyzed Chemoselective Oxidative Addition of Allyloxy-Tethered Aryl Iodides: Synthesis of Medium-Sized Rings and Mechanistic Studies.

This Letter describes a Pd-catalyzed Tsuji-Trost-type/Heck reaction with allyloxy-tethered aryl iodides and aziridines. The strategy provides efficient access to benzannulated medium-sized rings via intermolecular cyclization. The substrate aryl iodide has two oxidative addition sites, that is, the aromatic C-I bond and the allyl-oxygen bond.

Alkylation-Terminated Catellani Reactions by Cyclobutanol C-C Cleavage.

This report describes the first application of a cyclobutanol ring-opening procedure in the Catellani termination reaction, which includes two β-carbon elimination processes. This tandem reaction features mild conditions, high yields, good functional group tolerance, and a broad substrate scope. Meanwhile, four types of electrophiles (-benzoyloxyamines, alkyl iodides, aryl bromides, and benzyl chlorides) are quite compatible with this termination reaction for the construction of various types of polysubstituted aromatic hydrocarbons.

Three-component ruthenium-catalyzed remote C-H functionalization of 8-aminoquinoline amides.

Multicomponent reactions can efficiently construct complex molecular structures from simple precursors. Herein, a novel ruthenium-catalyzed three-component highly selective remote C-H functionalization of 8-aminoquinoline amides has been described. The reaction tolerates a wide range of functional groups, producing arylation/difluoroalkylation products of olefins with potential biological activity and pharmaceutical value.

Visible-Light-Induced Pd-Catalyzed Radical Strategy for Constructing -Vinyl Glycosides.

A novel visible-light-induced palladium-catalyzed Heck reaction for bromine sugars and aryl olefins with high regio- and stereochemistry selectivity for the preparation of glycosyl styrene is described. This reaction takes place in one step at room temperature by using a simple and readily available starting material. This protocol can be scaled up to a wide range of glycosyl bromide donors and aryl olefin substrates.

Palladium-Catalyzed -C-H Glycosylation/-Alkenylation of Aryl Iodides.

This report describes the first example of palladium-catalyzed -C-H glycosylation/-alkenylation of aryl iodides, and the easily accessible glycosyl chlorides are used as a glycosylation reagent. The reaction is compatible with the functional groups of the substrates, and a series of C-aryl glycosides have been synthesized in good to excellent yield and with excellent diastereoselectivity. It is found that a cheap 5-norbornene-2-carbonitrile as a transient mediator can effectively promote this reaction.

Copper-Catalyzed Three-Component Redox-Neutral Ring Opening of Benzothiazoles to 1-Amino--(2-(phenylthio)phenyl)methanimine.

Copper-catalyzed three-component redox-neutral ring opening of benzothiazoles with aryl iodides and -benzoyl hydroxylamines for the synthesis of 1-amino--(2-(phenylthio)phenyl)methanimine has been developed. This one-pot reaction undergoes C-S and N-O bond cleavage and new C-S and C-N bond construction. Several control experiments excluded a free radical procedure and also demonstrated the secondary amine as a possible intermediate, which was vital to the catalytic reaction.

A carboxylate-assisted amination/unactivated C(sp)-H arylation reaction via a palladium/norbornene cooperative catalysis.

This report describes a carboxylate-assisted palladium-catalysed Catellani reaction, which is compatible with ortho-amination and unactivated C(sp)-H arylation. This method was used to synthesize a series of 1-amino substituted dihydrophenanthridines, phenanthridines and 6H-benzo[c]chromenes. Based on kinetic isotope experiments, the kinetic curve proves that pivalic acid accelerates the reaction rate of unactivated C(sp)-H activation, and thus this rate can keep up with the five membered aryl-norbornene-palladacycle (ANP) intermediate.

Rapid colorimetric determination of dopamine based on the inhibition of the peroxidase mimicking activity of platinum loaded CoSn(OH) nanocubes.

Platinum nanoparticles were loaded on CoSn(OH)6 nanocubes via a co-precipitation method. The material (NCs) is shown to be a viable peroxidase mimic that catalyzes the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by hydrogen peroxide (HO) to generate oxidized TMB (oxTMB) with absorption at 652 nm. The formation of the blue color can be observed in <30 s.

[Effects of carbon supplementary modes on phosphorus bioaccumulation/phosphorus harvesting process in a tidal flow constructed wetland.].

We explored the effects of carbon supplementary modes on operational performance in a tidal flow constructed wetland (TFCW) utilizing phosphorus bioaccumulation/phosphorus harvesting (PB-PH) process. Three different carbon supplementary modes were adopted during the periodical phosphorus harvesting process. The results showed that the carbon supplementary mode significantly affected the performances of phosphorus bioaccumulation and phosphorus harvesting throughout the experiment.