Cooperative Iodine and Nitrate Catalyzed Oxidation of Stilbenes to α-Diketones in Water.

An efficient oxidation of stilbenes to α-diketones co-catalyzed by bismuth nitrate and iodine is reported. The utilization of molecular oxygen as a terminal oxidant and water as the reaction solvent provides a low-cost and environmentally friendly approach to preparing the α-diketone derivatives from readily available stilbenes. Isotope labeling experiments suggest that the two oxygen atoms of the α- diketone products mainly originate from water.

Development and Application of SPOSiPs: A Class of Diphosphine Ligands Based on SPOSiOL.

Here, we report the development and application of a novel class of spirosilacycle-based diphosphine ligands (SPOSiPs). This type of diphosphine ligand could be readily prepared in two steps with high efficiency starting from enantiopure spirobiphenoxasilin-diol (SPOSiOL). According to the structural analysis of SPOSiP and its PdCl complex, SPOSiPs possess a flexible chiral pocket and feature a rigid configuration, a large dihedral angle, a long P-P distance, and a large P-M-P bite angle in their metal complexes.

Copper-Catalyzed Borrowing Hydrogen Reaction for α-Alkylation of Amides with Alcohols.

We report the first example of copper-catalyzed α-alkylation of acetamides with alcohols via a borrowing hydrogen strategy. Catalyzed by the -generated copper particles, acetamides and various substituted benzyl or alkyl alcohols were transformed into functionalized amides in good yields with excellent selectivity. Compared with previous work, this process is simple using commercially available Cu(OAc) as a precatalyst, without an additional ligand or a metal complex, and easier.

The perception and interpretation of malaria among Chinese construction workers in sub-Saharan Africa: a qualitative study.

Background: Cooperation between China and Africa is deepening, and business, trade, and people-to-people exchanges are growing closer together, especially in the infrastructure construction field. At the same time, malaria has become a serious health concern for Chinese construction workers in Africa, who are at increased risk of infection and complications due to lack of immunity and exposure to high-transmission environments. One of the biggest challenges in fighting malaria is their lack of knowledge and misinterpretations about the disease, which can impact their need for interventions, adherence to treatments, and health services.

Study on the use and effectiveness of malaria preventive measures reported by employees of chinese construction companies in Western Africa in 2021.

Background: As malaria continues to be a significant global public health concern, especially in Sub-Saharan Africa, Chinese workers in Africa are at increased risk of malaria. The effectiveness of malaria prevention measures implemented by Chinese companies and workers is a question that may correlate with the malaria infection rate in this population. This study explored the use and effectiveness of malaria prevention measures for Chinese employees in West Africa to provide a reference for companies and individuals on improving malaria prevention and control.

Access to functionalized alkynylcyclopropanes reductive radical-polar crossover-based reactions of 1,3-enynes with alkyl radicals.

Herein, using a single-electron-transfer reduction-based radical-polar crossover process as a strategy, protocols dealing with the preparation of functionalized alkynylcyclopropanes have been successfully developed the reactions of 1,3-enynes with alkyl radicals. In addition to redox-neutral photocatalysis, nickel catalysis with zinc as the reductant is also an alternative to enable reactions of 1,3-enynes with redox-active -hydroxyphthalimide esters. The synthetic application of alkynylcyclopropane has also been demonstrated.

Baseline Sensitivity and Control Efficacy of Two Quinone Outside Inhibitor Fungicides, Azoxystrobin and Pyraclostrobin, Against .

Rice false smut caused by the filamentous fungus is a devastating grain disease in rice. Fungicides have been an important measure for the control of this disease. In this study, baseline sensitivities of 179 isolates of to the quinone outside inhibitor (QoI) fungicides azoxystrobin and pyraclostrobin were established.

Predictors for HIV testing among Chinese workers in infrastructure construction enterprises in Kenya.

Background: There are increasing Chinese migrants in sub-Saharan Africa currently. Most of them are engaged in infrastructure construction. Research has shown that they stay at particular risk of HIV and are recommended for HIV testing.

Rapid Access to Fluorinated Anilides via DAST-Mediated Deoxyfluorination of Arylhydroxylamines.

A new strategy for the synthesis of fluorinated anilides in the absence of metals and oxidants has been developed. This deoxyfluorination of -arylhydroxylamines with diethylaminosulfur trifluoride (DAST) proceeded smoothly under mild conditions, and the - or -fluorinated aromatic amine products were prepared in moderate to good yields. Structurally diverse fluorinated anilides, including heterocyclic and pharmaceutically relevant molecules, can be efficiently constructed by this protocol.

Fluorescence detection of malachite green in fish tissue using red emissive Se,N,Cl-doped carbon dots.

Facile detection of malachite green (MG), a toxic dye, in aquaculture is urgently demanded for environment and food safety. Herein, we design a novel fluorescent probe, namely red emissive Se,N,Cl-doped carbon dots (CDs), to accurately determinate MG. CDs are prepared by hydrothermal treatment of selenourea and o-phenylenediamine in HCl solution.

Catalytic Asymmetric C-H Arylation of (η-Arene)Chromium Complexes: Facile Access to Planar-Chiral Phosphines.

A catalytic asymmetric direct C-H arylation of (η-arene)chromium complexes to obtain planar-chiral compounds is reported. The use of the hemilabile ligand H-BINAP(O) is key to providing high enantioselectivity in this transformation. We show that this methodology opens the door to the synthesis of a variety of planar-chiral chromium derivatives which can be easily transformed into planar chiral mono- or diphosphines.

Transition Metal-Catalyzed Directing-Group-Assisted C-H Activation of Phenols.

Strategies that exploit directing groups to control the site selectivity in the C-H activation of arenes have received much attention during the past two decades. In light of the importance of phenol derivatives in the areas of pharmaceuticals, agrochemicals, and materials science, transition-metal-catalyzed C-H activation of phenols has proven to be an extremely useful tool in organic synthesis. This Minireview summarizes the current state-of-the-art direct C-H activation of phenol derivatives under transition-metal catalysis.

Adherence to self-monitoring of blood glucose in Chinese patients with type 2 diabetes: current status and influential factors based on electronic questionnaires.

Background And Purpose: Self-monitoring of blood glucose (SMBG) is important to the management of diabetes mellitus, yet most patients with type 2 diabetes mellitus (T2DM) do not perform SMBG as recommended. The current status and influential factors of SMBG in China have not been well investigated. This study aimed to describe the present status of SMBG adherence in China and investigate the influential factors based on electronic questionnaires.

C-H Carboxylation of Aromatic Compounds through CO Fixation.

Carbon dioxide (CO ) represents the most abundant and accessible carbon source on Earth. Thus the ability to transform CO into valuable commodity chemicals through the construction of C-C bonds is an invaluable strategy. Carboxylic acids and derivatives, the main products obtained by carboxylation of carbon nucleophiles by reaction of CO , have wide application in pharmaceuticals and advanced materials.

Carboxylation of Phenols with CO2 at Atmospheric Pressure.

A convenient and efficient method for the ortho-carboxylation of phenols under atmospheric CO2 pressure has been developed. This method provides an alternative to the previously reported Kolbe-Schmitt method, which requires very high pressures of CO2 . The addition of a trisubstituted phenol has proved essential for the successful carboxylation of phenols with CO2 at standard atmospheric pressure, allowing the efficient preparation of a broad variety of salicylic acids.

A Domino Oxidation/Arylation/Protodecarboxylation Reaction of Salicylaldehydes: Expanded Access to meta-Arylphenols.

A method that allows salicylaldehydes to be efficiently transformed into meta-arylated phenol derivatives through a cascade oxidation/arylation/protodecarboxylation sequence is presented. We demonstrate that the aldehyde functional group can be used as a convenient removable directing group to control site selectivity in C-H activation. Aldehydes are easily introduced into the starting materials and the group is readily cleaved after the C-H functionalization event.

Salicylic acids as readily available starting materials for the synthesis of meta-substituted biaryls.

Salicylic acids are shown to be readily available and versatile starting materials that easily undergo a tandem arylation-protodecarboxylation process under Pd-catalysis. The corresponding meta-arylphenols can subsequently be easily transformed into a variety of meta-functionalized biaryls, highlighting the versatility of this approach to access this structural motif.

Overriding ortho-para selectivity via a traceless directing group relay strategy: the meta-selective arylation of phenols.

The direct functionalization of phenols at the ortho and para position is generally facilitated by the electron-donating nature of the hydroxyl group. Accessing meta-functionalized phenols from the parent phenols, on the other hand, generally requires lengthy synthetic sequences. Here, we report the first methodology for the one-pot direct meta-selective arylation of phenols.