Direct carbonyl reductive functionalizations by diphenylphosphine oxide.

Reductive functionalization of aldehydes and ketones is one of the most challenging but ultimately rewarding areas in synthetic chemistry and related sciences. We report a simple and extremely versatile carbonyl reductive functionalization strategy achieving direct, highly selective, and efficient reductive amination, etherification, esterification, and phosphinylation reactions of (hetero)aryl aldehydes and ketones, which are extremely challenging or unattainable to achieve by traditional strategies, using only diphenylphosphine oxide and an inorganic base. It enables modular synthesis of functionally and structurally diverse tertiary amines, ethers, esters, phosphine oxides, etc.

General (hetero)polyaryl amine synthesis via multicomponent cycloaromatization of amines.

(Hetero)polyaryl amines are extensively prevalent in pharmaceuticals, fine chemicals, and materials but the intricate and varied nature of their structures severely restricts their synthesis. Here, we present a selective multicomponent cycloaromatization of structurally and functionally diverse amine substrates for the general and modular synthesis of (hetero)polyaryl amines through copper(I)-catalysis. This strategy directly constructs a remarkable range of amino group-functionalized (hetero)polyaryl frameworks (194 examples), including naphthalene, binaphthalene, phenanthren, benzothiophene, dibenzothiophene, benzofuran, dibenzofuran, quinoline, isoquinoline, quinazoline, and others, which are challenging or impossible to obtain using alternative methods.

Direct synthesis of α-functionalized amides via heteroatom-hydrogen insertion reactions using amide-sulfoxonium ylides.

α-Functionalized Si-, Ge-, B-, Se-, and S-amide moieties are present in many medicinally active molecules, but their synthesis remains challenging. Here, we demonstrate a high-throughput synthesis using amide-sulfoxonium ylides as carbene precursors in a Si-H, Ge-H, B-H, Se-H, and S-H insertion reactions to target a wide range of α-silyl, α-geryl, α-boryl, α-selenyl, and α-sulfur (hetero)amides. The process is featured as simple operation, mild conditions, broad substrate scope, high functional group compatibility, and excellent chemoselectivity.

Development of a quadruple qRT-PCR assay for simultaneous identification of hypervirulent and carbapenem-resistant .

Globally, the increasing number of hypervirulent (hvKp) and carbapenem-resistant Kp (CR-Kp) infections poses a huge public health challenge with high morbidity and mortality. Worrisomely, due to the mobility of elements carrying virulence and drug-resistance genes, the increasing prevalence of CR-hvKp has also been found with an overwhelming mortality rate in recent years. However, the current detection methods for hvKp and CR-Kp have many disadvantages, such as long turnaround time, complex operation, low sensitivity, and specificity.

High-Throughput Experimentation and Machine Learning-Assisted Optimization of Iridium-Catalyzed Cross-Dimerization of Sulfoxonium Ylides.

A novel and convenient approach that combines high-throughput experimentation (HTE) with machine learning (ML) technologies to achieve the first selective cross-dimerization of sulfoxonium ylides via iridium catalysis is presented. A variety of valuable amide-, ketone-, ester-, and N-heterocycle-substituted unsymmetrical E-alkenes are synthesized in good yields with high stereoselectivities. This mild method avoids the use of diazo compounds and is characterized by simple operation, high step-economy, and excellent chemoselectivity and functional group compatibility.

A deep learning framework for accurate reaction prediction and its application on high-throughput experimentation data.

In recent years, it has been seen that artificial intelligence (AI) starts to bring revolutionary changes to chemical synthesis. However, the lack of suitable ways of representing chemical reactions and the scarceness of reaction data has limited the wider application of AI to reaction prediction. Here, we introduce a novel reaction representation, GraphRXN, for reaction prediction.

Assessment of antibody responses against SARS-CoV-2 in unvaccinated individuals and vaccinees from Omicron-BA.2 infection in Zhaoqing, Guangdong Province, China.

Currently, the majority of the global population has been vaccinated with the COVID-19 vaccine, and characterization studies of antibodies in vivo from Omicron breakthrough infection and naive infection populations are urgently needed to provide pivotal clues about accurate diagnosis, treatment, and next-generation vaccine design against SARS-CoV-2 infection. We showed that after infection with Omicron-BA.2, the antibody levels of specific IgM against the Wuhan strain and specific IgG against Omicron were not significantly elevated within 27 days of onset.

Copper-Catalyzed Nitrogen Atom Transfer to Isoquinolines via C-N Triple Bond Cleavage and Three-Component Cyclization.

A copper(I)-catalyzed tandem reaction of 2-bromoaryl ketones, terminal alkynes, and CHCN is developed, which combines N atom transfer and three-component [3 + 2 + 1] cyclization, and efficiently produces densely functionalized isoquinolines in a facile, highly selective, and general manner. In the reaction, the formation of aromatic C-N bonds along with the complete C-N triple bond cleavage is first realized; Cu(III)-acetylide species might serve as the intermediates, which allow highly selective 6-- cyclization.

Copper-Catalyzed 6-- Cyclization-Coupling of 2-Bromoaryl Ketones and Terminal Alkynes toward Naphthyl Aryl Ethers in Water.

The cyclization-coupling reaction of 2-bromoaryl ketones and terminal alkynes is first realized by copper catalysis, which produces polyfunctional naphthyl aryl ethers in moderate to excellent yields with broad substrate scope and good functional group tolerance. This reaction proceeds via 6-- cyclization and C(sp)-O coupling using green HO as the unique solvent and 5-bromopyrimidin-2-amine as the critical additive. Mechanistically, a unique Cu(III)-acetylide probably is the key intermediate, which allows exclusive 6-- selectivity.

Cu(i) catalysis for selective condensation/bicycloaromatization of two different arylalkynes: direct and general construction of functionalized C-N axial biaryl compounds.

Selective condensation/bicycloaromatization of two different arylalkynes is firstly developed under ligand-free copper(i)-catalysis, which allows the direct synthesis of C-N axial biaryl compounds in high yields with excellent selectivity and functional group tolerance. Due to the critical effects of Cu(i) catalyst and HFIP, many easily occurring undesired reactions are suppressed, and the coupled five-six aromatic rings are constructed the selective formation of two C(sp)-N(sp) bonds and four C(sp)-C(sp) bonds. The achievement of moderate enantioselectivity verifies its potential for the simplest asymmetric synthesis of atropoisomeric biaryls.

Molecular Epidemiological Analysis of ST11-K64 Extensively Drug-Resistant Infections Outbreak in Intensive Care and Neurosurgery Units Based on Whole-Genome Sequencing.

(Kp) is the primary causative bacteria for nosocomial infections and hospital outbreaks. In particular, extensively drug-resistant (XDRKp) causes severe clinical infections in hospitalized patients. Here, we used pulsed-field gel electrophoresis (PFGE), drug susceptibility tests, and the whole-genome sequencing (WGS) technology to examine genetic relatedness and phenotypic traits of the strains isolated during an outbreak period.

Cu-Catalyzed Oxidative Thioesterification of Aroylhydrazides with Disulfides.

An alternative thioesterification reaction via copper-catalyzed oxidative coupling of readily available aroylhydrazides with disulfides is developed, in which oxidative expulsion of N overcomes the activation barrier between the carboxylic acid derivatives and the products. The reaction produces various thioesters in good to excellent yields with good functional group tolerance. In the reaction, stable and easily available aroylhydrazides are used as acyl sources and the relatively odorless disulfides are used as S sources.

Selective Oxidative Cleavage of 3-Methylindoles with Primary Amines Affording Quinazolinones.

A selective functionalization of C-C═C bonds toward N-C═O bonds is realized by an -BuNI-catalyzed reaction of 3-methylindoles with primary amines using TBHP as the unique oxidant. The systematic process involves oxygenation, nitrogenation, ring-opening, and recyclization, affording a broad range of quinazolinones in good to excellent yields.

General Oxidative Aryl C-P Bond Formation through Palladium-Catalyzed Decarbonylative Coupling of Aroylhydrazides with P(O)H Compounds.

Oxidative C-C/P-H cross-coupling is achieved via Pd-catalyzed decarbonylative cross-coupling of aroylhydrazides with P(O)H compounds. The unique cooperative reaction system, especially the Brønsted acid and bidentate phosphine ligand, allows the selective activation of the inert C-C bond and the suppression of the undesired oxidation and coordination of >P(O)-H compounds, leading to a general oxidative synthesis of aryl phosphorus compounds from easily available substrates.

Cu(I)-Catalyzed 6- endo-dig Cyclization of Terminal Alkynes, 2-Bromoaryl Ketones, and Amides toward 1-Naphthylamines: Applications and Photophysical Properties.

Functional group substituted 1-naphthylamines, especially N-methylated ones, play important roles in numerous chemical and biological processes. However, these compounds' general and step-economic syntheses are highly limited, which seriously restricts efforts to improve the properties and develop new functions for this kind of compound. In this report, we describe the development of an efficient, convenient, and general method for the synthesis of valuable functionalized 1-naphthylamines directly from readily available terminal alkynes, 2-bromoaryl ketones, and amides via Cu(I)-catalyzed benzannulation in a green solvent (i.

Palladium-Catalyzed Regio- and Stereoselective Coupling-Addition of Propiolates with Arylsulfonyl Hydrazides: A Pattern for Difunctionalization of Alkynes.

A new pattern for difunctionalization of alkynes via a palladium-catalyzed regio- and stereoselective coupling-addition of propiolates with arylsulfonyl hydrazides is disclosed. The approach enables the synthesis of various highly functionalized ( E)-vinylsulfones in satisfactory yields. Arylsulfonyl hydrazides act as both aryl and sulfonyl sources via selective cleavage of Ar(C)-S and S-N bonds, which are simultaneously incorporated onto the terminal carbon atom of an alkyne molecule.

Cyclization of Ketones with Nitriles under Base: A General and Economical Synthesis of Pyrimidines.

A facile, general, and economical synthesis of diversely functionalized pyrimidines has been realized under basic conditions via the copper-catalyzed cyclization of ketones with nitriles. The reaction proceeds via a novel pathway involving the nitriles acting as electrophiles and consecutive C-C bond and two C-N bond formations and shows broad substrate scope and good tolerance of many important functional groups. This strategy represents a new platform for constructing pyrimidine structures.

Copper Catalysis for Selective Heterocoupling of Terminal Alkynes.

A Cu-catalyzed selective aerobic heterocoupling of terminal alkynes is disclosed, which enables the synthesis of a broad range of unsymmetrical 1,3-diynes in good to excellent yields. The results disprove the long-held belief that homocouplings are exclusively favored in the Glaser-Hay reaction.