Catalytic Asymmetric Oxidative Coupling between C(sp)-H Bonds and Carboxylic Acids.

The direct enantioselective functionalization of C(sp)-H bonds in organic molecules could fundamentally transform the synthesis of chiral molecules. In particular, the enantioselective oxidation of these bonds would dramatically change the production methods of chiral alcohols and esters, which are prevalent in natural products, pharmaceuticals, and fine chemicals. Remarkable advances have been made in the enantioselective construction of carbon-carbon and carbon-nitrogen bonds through the C(sp)-H bond functionalization.

Circadian rhythm genes contribute to the prognosis prediction and potential therapeutic target in gastric cancer.

The role of circadian rhythm genes (CRGs) in gastric cancer (GC) is poorly understood. This study aimed to develop a CRG signature to improve understanding of prognosis and immunotherapy responses in GC patients. We integrated the The Cancer Genome Atlas-Stomach adenocarcinoma (TCGA-STAD) dataset with CRGs to develop a prognostic signature for GC.

Stereoconvergent and Enantioselective Synthesis of -Homoallylic Alcohols via Nickel-Catalyzed Reductive Coupling of /-1,3-Dienes with Aldehydes.

Stereoconvergent reactions enable the transformation of mixed stereoisomers into well-defined, chiral products─a crucial strategy for handling /-mixed olefins, which are common but challenging substrates in organic synthesis. Herein, we report a stereoconvergent and highly enantioselective method for synthesizing -homoallylic alcohols via the nickel-catalyzed reductive coupling of /-mixed 1,3-dienes with aldehydes. This process is enabled by an -heterocyclic carbene ligand characterized by -symmetric backbone chirality and bulky 2,6-diisopropyl -aryl substituents.

Associations of cognitive impairment and longitudinal change in cognitive function with the risk of fatal stroke in middle-aged to older Chinese.

It is unclear whether cognitive impairment and the longitudinal change in cognition are associated with the risk of fatal stroke in aging populations. Based on the Guangzhou Biobank Cohort Study data a sum of 26,064 participants at baseline and all deaths caused by stroke in a mean follow-up of 14.3 years (standard deviation = 3.

Construction of Ge-Stereogenic Center by Desymmetric Carbene Insertion of Dihydrogermanes.

We developed a method for the enantioselective synthesis of germanium-stereogenic compounds by the desymmetric carbene insertion of dihydrogermanes. A chiral rhodium phosphate catalyst decomposes diaryldiazo-methanes to generate rhodium carbenes that insert enantioselectively into one of the two Ge-H bonds of dihydrogermanes to form germanium-stereogenic compounds under mild reaction conditions. By this method, a variety of chiral germanes with germanium-stereogenic centers were synthesized in high yields and excellent enantioselectivities.

Ligand-Controlled Regiodivergent Nickel-Catalyzed Hydroaminoalkylation of Unactivated Alkenes.

Ligand modulation of transition-metal catalysts to achieve optimal reactivity and selectivity in alkene hydrofunctionalization is a fundamental challenge in synthetic organic chemistry. Hydroaminoalkylation, an atom-economical approach for alkylating amines using alkenes, is particularly significant for amine synthesis in the pharmaceutical, agrochemical, and fine chemical industries. However, the existing methods usually require specific substrate combinations to achieve precise regio- and stereoselectivity, which limits their practical utility.

Diastereodivergent and Enantioselective Synthesis of Homoallylic Alcohols via Nickel-Catalyzed Borylative Coupling of 1,3-Dienes with Aldehydes.

We present the first enantioselective nickel-catalyzed borylative coupling of 1,3-dienes with aldehydes, providing an efficient route to highly valuable homoallylic alcohols in a single step. The reaction involves the 1,4-carboboration of dienes, leading to the formation of C-C and C-B bonds accompanied by the construction of two continuous stereogenic centers. Enabled by a chiral spiro phosphine-oxazoline nickel complex, this transformation yields products with exceptional diastereoselectivity, -selectivity, and enantioselectivity.

Practical synthesis of allylic amines nickel-catalysed multicomponent coupling of alkenes, aldehydes, and amides.

Molecules with an allylic amine motif provide access to important building blocks and versatile applications of biologically relevant chemical space. The need for diverse allylic amines requires the development of increasingly general and modular multicomponent reactions for allylic amine synthesis. Herein, we report an efficient catalytic multicomponent coupling reaction of simple alkenes, aldehydes, and amides by combining nickel catalysis and Lewis acid catalysis, thus providing a practical, environmentally friendly, and modular protocol to build architecturally complex and functionally diverse allylic amines in a single step.

Synthesis of Highly Substituted Aminotetrahydropyrans Enabled by Stereospecific Multivector C-H Functionalization.

Highly substituted aminotetrahydropyrans were synthesized via sequential C-H functionalizations. The process was initiated with a Pd(II)-catalyzed stereoselective γ-methylene C-H arylation of aminotetrahydropyran, followed by α-alkylation or arylation of the corresponding primary amine. The initial γ-C-H (hetero)arylation was compatible with a range of aryl iodides containing various substituents and provided the corresponding products in moderate to good yields.

Ketone α-alkylation at the more-hindered site.

Control of the regioselectivity of α-alkylation of carbonyl compounds is a longstanding topic of research in organic chemistry. By using stoichiometric bulky strong bases and carefully adjusting the reaction conditions, selective alkylation of unsymmetrical ketones at less-hindered α-sites has been achieved. In contrast, selective alkylation of such ketones at more-hindered α-sites remains a persistent challenge.

KRT80 expression works as a biomarker and a target for differentiation in gastric cancer.

Keratin 80 (KRT80) is a filament protein that participates in cell differentiation and the integrity of the epithelial barrier. Here, KRT80 expression was higher in gastric cancer compared with normal mucosa at both mRNA and protein levels by bioinformatic analysis, qRT-PCR and Western blot (p<0.05), however, the methylation of KRT80 was lower than in normal mucosa (p<0.

Oncogenic roles of GPR176 in breast cancer: a potential marker of aggressiveness and a potential target of gene therapy.

Background: Belonging to the G-protein coupled receptor 1 family, G protein-coupled receptor 176 (GPR176) is associated with the Gz/Gx G-protein subclass and is capable of decreasing cAMP production.

Methods: GPR176 expression was detected by qRT-PCR, bioinformatics analysis, Western blot and immunohistochemistry, and compared with clinicopathological characteristics of breast cancer. GPR176-related genes and pathways were subjected to bioinformatic analysis.

Intermolecular Enantioselective Benzylic C(sp )-H Amination by Cationic Copper Catalysis.

Chiral benzylic amines are privileged motifs in pharmacologically active molecules. Intramolecular enantioselective radical C(sp )-H functionalization by hydrogen-atom transfer has emerged as a straightforward, powerful tool for the synthesis of chiral amines, but methods for intermolecular enantioselective C(sp )-H amination remain elusive. Herein, we report a cationic copper catalytic system for intermolecular enantioselective benzylic C(sp )-H amination with peroxide as an oxidant.

The effects of REG4 expression on chemoresistance of ovarian cancer.

Although ovarian cancer usually responds well to platinum- and taxane-based first-line chemotherapy, most patients develop recurrence and chemoresistance. Regenerating gene 4 (REG4) is a secretory protein involved in cell differentiation and proliferation. We found higher REG4 expression in ovarian cancer than in normal tissues ( < .

Palladium(II)-Catalyzed Selective Arylation of Tertiary C-H Bonds of Cyclobutylmethyl Ketones Using Transient Directing Groups.

We report the first example of selective Pd -catalyzed tertiary C-H activation of cyclobutylmethyl ketones using a transient directing group. An electron-deficient 2-pyridone ligand was identified as the optimal external ligand to enable tertiary C-H activation. A variety of cyclobutylmethyl ketones bearing quaternary carbon centers was readily accessed without preinstalling internal directing groups in up to 81 % yield and >95 : 5 regioisomeric ratios of tertiary C-H arylation to β-methylene (β-methyl) or γ-C-H arylation.

Nickel-Catalyzed Desymmetric Reductive Cyclization/Coupling of 1,6-Dienes: An Enantioselective Approach to Chiral Tertiary Alcohol.

We have developed a nickel-catalyzed desymmetric reductive cyclization/coupling of 1,6-dienes. The reaction provides an efficient method for constructing a chiral tertiary alcohol and a quaternary stereocenter by a single operation. The method has excellent diastereoselectivity and high enantioselectivity, a broad substrate scope, as well as good tolerance of functional groups.

Nickel-Catalyzed Intramolecular Hydroalkenylation of Imines.

A ligand-enabled nickel-catalyzed intramolecular hydroalkenylation of imines with unactivated alkenes has been developed. A variety of five- and six-membered cyclic allylic amines were synthesized in high yields. The use of both wide-bite-angle diphosphine ligand and Brønsted acid is crucial for realizing the reaction.

Palladium-Catalyzed Asymmetric Hydrosulfonylation of 1,3-Dienes with Sulfonyl Hydrazides.

A highly enantio- and regioselective hydrosulfonylation of 1,3-dienes with sulfonyl hydrazides has been realized by using a palladium catalyst containing a monodentate chiral spiro phosphoramidite ligand. The reaction provided an efficient approach to synthetically useful chiral allylic sulfones. Mechanistic studies suggest that the reaction proceeds through the formation of an allyl hydrazine intermediate and subsequent rearrangement to the chiral allylic sulfone product.

[Simultaneous Quantitative Detection of Thirteen Common Antibiotics in Leafy Vegetables by Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry].

An analytical approach was developed to simultaneously determine 13 antibiotics in sulfonamides, quinolones, and macrolides in leafy vegetables by ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-MS/MS). After optimizing extracted solutions, purification methods, and eluents of antibiotics in vegetable substrates, and taking into account the influence of environmental changes and experimental conditions on the results, the optimal experimental scheme was determined. This involved ①weighing 500 mg of vegetable samples and adding 20 mL of methanol-Mcllvaine-Na EDTA solution; ② conducting ultrasonic and centrifugal extraction three times; ③ Allowing rotary evaporation to 20 mL to pass a HLB solid phase extraction column; ④ Eluting the extraction column using 6 mL of methanol, upon which the eluent was dried almost completely; ⑤ Re-dissolving the eluent with a mixed solution of acetonitrile:water (volume ratio of 2:8); ⑥ Detecting by UPLC-MS/MS after centrifugation and filtering.

Pd -Catalyzed Enantioselective C(sp )-H Arylation of Cyclobutyl Ketones Using a Chiral Transient Directing Group.

The use of chiral transient directing groups (TDGs) is a promising approach for developing Pd -catalyzed enantioselective C(sp )-H activation reactions. However, this strategy is challenging because the stereogenic center on the TDG is often far from the C-H bond, and both TDG covalently attached to the substrate and free TDG are capable of coordinating to Pd centers, which can result in a mixture of reactive complexes. We report a Pd -catalyzed enantioselective β-C(sp )-H arylation reaction of aliphatic ketones using a chiral TDG.

Nickel-catalyzed hydroalkylation and hydroalkenylation of 1,3-dienes with hydrazones.

Transition-metal-catalyzed hydrofunctionalization of 1,3-dienes is a useful and atom-economical method for constructing allylic compounds. Although substantial progress on hydroalkylation of dienes with stabilized carbon nucleophiles has been made, hydroalkylation of dienes with unstabilized carbon nucleophiles has remained a challenge. In this article, we report a protocol for nickel-catalyzed hydroalkylation of dienes with hydrazones, which serve as equivalents of alkyl carbon nucleophiles.