Gold Self-Relay Catalysis Enabling Regioselective Bicyclization toward [5]Azahelicenes.

A gold self-relay catalysis driving a double annulation cascade starting from soft electron-biased 1,2-di(-aminoaryl)alkynes and aldehydes is reported, enabling regioselective access to produce a series of [5]azahelicenes depending on the substitution pattern in generally good yields under mild conditions. This protocol exploits and unifies the π- and σ-Lewis acid capability of gold catalysts, featuring high molecular convergence, broad substrate flexibility, and good functional group compatibility and regioselectivity.

Selective Functionalization of Alkenes and Alkynes by Dinuclear Manganese Catalysts.

ConspectusAlkenes and alkynes are fundamental building blocks in organic synthesis due to their commercial availability, bench-stability, and easy preparation. Selective functionalization of alkenes and alkynes is a crucial step for the synthesis of value-added compounds. Precise control over these reactions allows efficient construction of complex molecules with new functionalities.

Dinuclear gold-catalyzed divergent dechlorinative radical borylation of gem-dichloroalkanes.

The enormous and widespread use of organoboronic acids has prompted the development of innovative synthetic methodologies to meet the demands on structural diversity and functional group tolerance. The existing photoinduced defunctionalization radical borylation, typically focused on the conversion of one C-X bond (X= Br, I, or other leaving group) into only one C-B bond. Herein, we disclose a divergent radical dechloroborylation reaction enabled by dinuclear gold catalysis with visible light irradiation.

Photoinduced activation of alkyl chlorides.

In recent years, the activation of unactivated alkyl chlorides through light-induced processes has emerged as a promising field in radical chemistry, and has led to new transformations in organic synthesis. Direct utilization of alkyl chlorides as C(sp)-hybridized electrophiles enables the facile construction of carbon-carbon and carbon-heteroatom bonds. Furthermore, recent studies in medicinal chemistry indicate that their presence is associated with high levels of success in clinical trials.

Dinuclear-gold-catalyzed cyclization of 1,7-enynes with alkyl bromides.

Dinuclear-gold-catalyzed radical difunctionalization of alkyl bromides with 1,7-enynes has been established dehalogenation and 1,5-HAT processes. This protocol was used to construct, in a facile and efficient manner, a wide range of cyclopenta[]quinolines bearing two quaternary carbon centers with good yields (28 examples, up to 84% yield). The good functional group compatibility and gram-scale preparation ability of the reaction proved its synthetic robustness.

Anterior controllable antedisplacement and fusion: quantitative analysis of a single surgeon's learning experience.

Background Context: Anterior controllable antedisplacement and fusion (ACAF) is a novel surgical technique for the treatment of ossification of the posterior longitudinal ligament (OPLL) but the surgical learning curve for this technique has not been previously characterized.

Purpose: The aim of this study was to quantify a surgeon's learning curve for ACAF and the effect of surgeon experience on postoperative outcomes.

Study Design: Prospective study of a single institution and single surgeon experience with ACAF surgery.

The clinical value of three-dimensional measurement in the diagnosis of thoracic myelopathy caused by ossification of the ligamentum flavum.

Background: Thoracic ossification of the ligamentum flavum (OLF) is a major cause of thoracic myelopathy, which is often accompanied by multiple segmental stenosis or other degenerative spinal diseases. However, in the above situations, it is difficult to determine the exact segment responsible. The objective of this study was to analyze three-dimensional (3D) radiological parameters in order to establish a novel diagnostic method for discriminating the responsible segment in OLF-induced thoracic myelopathy, and to evaluate its superiority compared to the conventional diagnostic methods.

[Biocontrol effect and mechanism of Bl13 against early blight disease of tomato].

Bl13 has good antagonistic effect on the pathogen of tomato early blight (TEB) disease. A pot experiment was conducted to investigate the effect and mechanism of Bl13 against TEB disease by measuring biological traits such as plant height, stem diameter, disease index of TEB, activity of plant defense enzyme in leaves, and microbial diversity and community composition in root area. The results showed that Bl13 could significantly reduce the disease index of TEB disease incidence, increase the activity of defensive enzymes including polyphenol oxidase (PPO) and peroxidase (POD) in leaves, and reduce the effects of the disease on the aboveground and root growth of tomato.

Dinuclear gold catalysis.

Gold chemistry has developed extensively in the past decade, and a dozen good reviews have been presented discussing this progress. Few however have paid close attention to the progress in organic synthesis of dinuclear gold-catalysis. A dinuclear gold catalyst is defined here as a gold complex with two gold centers linked by a bidentate ligand.

Catalytic Three-Component Synthesis of Functionalized Naphtho[2,1-]oxecines via a Double Bond Cleavage-Rearrangement Cascade.

A new double annulation cascade involving a [2 + 2] cycloaddition-retroelectrocyclization (CA-RE) process was first reported, leading to the generation of unprecedented dibenzoannulated naphtho[2,1-]oxecines with good to excellent yields and high stereoselectivity through catalytic scission/recombination of C-C double bonds under the mild conditions. An Y(OTf)-catalyzed three-component reaction of α-alkynyl naphthalen-2-ols with β,γ-unsaturated α-ketoesters enabled direct ring expansion of the naphthalene ring and carbon-carbon double bond cleavage/rearrangement of α-ketoesters to give macrocyclic architectures.