Total Synthesis of Laingolide B Stereoisomers and Assignment of Absolute Configuration

Total synthesis of (−)-(2<i>R</i>,9<i>S</i>)- and (+)-(2<i>S</i>,9<i>S</i>)-stereoisomers of laingolide B has been accomplished by using sequential ring-closing metathesis (RCM) and alkene isomerization to construct the macrocyclic <i>trans</i>-<i>N</i>-methyl enamide moiety. The Myers alkylation was used to secure the C2 stereochemistry of the two RCM precursors from a common (9<i>S</i>)-C3–C9 alkyl iodide. The absolute configuration of laingolide B has been assigned as (2<i>S</i>,9<i>R</i>) by comparison of the optical rotation data

Data_Sheet_1_What factors affect Beijing residents’ contracts with family doctors? A comparative study of Beijing’s urban and suburban areas.PDF

ObjectiveTo improve the health of residents and promote hierarchical diagnosis and treatment to achieve an orderly pattern of medical treatment, Beijing implemented family doctor contract services (FDCSs) in 2011. The aims of this study were to analyze the current status of Beijing residents’ contracts with family doctors (FDs), compare the differences in contracting between urban and suburban residents, and explore the factors that affect residents’ contract behavior.MethodsFrom August 2020 to October 2020, a stratified sampling method was adopted to select residents from community health centers (CHCs) in districts D (urban area) and S (suburb) of Beijing to conduct a questionnaire survey. Chi-square tests, rank sum tests and logistic regression analyzes were used to analyze the current status and influencing factors of residents’ contracting with FDs.ResultsA total of 4,113 valid questionnaires were included in the final analysis. District D was rich in medical resources, and the FD contract rate of residents there (93.09%) was significantly higher than that of residents in district S (78.06%; p ConclusionThis study shows that residents who are located in districts with rich medical resources, prefer CHCs as their first choice, have a better understanding of FDCS policies, and are more inclined to contract with FDs than other residents. It is recommended that the number and quality of FDs in suburban areas be increased and that medical staff strengthen publicity about FDCSs and actively encourage residents to contract with FDs.</p

Additional file1: of The willingness of patients to make the first visit to primary care institutions and its influencing factors in Beijing medical alliances: a comparative study of Beijing’s medical resource-rich and scarce regions

Questionnaire for patients. The content of questionnaire for patients used in the study. (DOC 41 kb

Microwave-Assisted Intramolecular Ullmann Diaryl Etherification as the Post-Ugi Annulation for Generation of Dibenz[<i>b</i>,<i>f</i>][1,4]oxazepine Scaffold

A sequence of the Ugi four-component reaction (U-4CR) and microwave-assisted intramolecular Ullmann etherification has been established for efficient generation of a dibenz­[<i>b</i>,<i>f</i>]­[1,4]­oxazepine scaffold. The U-4CR, using 2-aminophenols and 2-bromobenzoic acids or 2-bromobenzaldehydes as the inputs, was carried out in MeOH at 50–60 °C for 2–3 days to form a collection of 22 linear products in 46–90% yields. A microwave-assisted intramolecular Ullmann etherification was then used to transform these acyclic U-4CR products into the cleft-shaped 6/7/6-fused tricyclic heterocycles. The intramolecular Ullmann diaryl ether formation was catalyzed by 10 mol % of CuI and 30 mol % of <i>N</i>,<i>N</i>-dimethylglycine hydrochloride (DMG·HCl) in the presence of Cs₂CO₃ with microwave irradiation (150 °C, 30 min) to furnish dibenz­[<i>b</i>,<i>f</i>]­[1,4]­oxazepin-11­(10<i>H</i>)-ones and dibenz­[<i>b</i>,<i>f</i>]­[1,4]­oxazepin-11­(10<i>H</i>)-carboxamides in 64–100% yields

Data_Sheet_2_What factors affect Beijing residents’ contracts with family doctors? A comparative study of Beijing’s urban and suburban areas.PDF

ObjectiveTo improve the health of residents and promote hierarchical diagnosis and treatment to achieve an orderly pattern of medical treatment, Beijing implemented family doctor contract services (FDCSs) in 2011. The aims of this study were to analyze the current status of Beijing residents’ contracts with family doctors (FDs), compare the differences in contracting between urban and suburban residents, and explore the factors that affect residents’ contract behavior.MethodsFrom August 2020 to October 2020, a stratified sampling method was adopted to select residents from community health centers (CHCs) in districts D (urban area) and S (suburb) of Beijing to conduct a questionnaire survey. Chi-square tests, rank sum tests and logistic regression analyzes were used to analyze the current status and influencing factors of residents’ contracting with FDs.ResultsA total of 4,113 valid questionnaires were included in the final analysis. District D was rich in medical resources, and the FD contract rate of residents there (93.09%) was significantly higher than that of residents in district S (78.06%; p ConclusionThis study shows that residents who are located in districts with rich medical resources, prefer CHCs as their first choice, have a better understanding of FDCS policies, and are more inclined to contract with FDs than other residents. It is recommended that the number and quality of FDs in suburban areas be increased and that medical staff strengthen publicity about FDCSs and actively encourage residents to contract with FDs.</p

DataSheet1_A hybrid system for the overproduction of complex ergot alkaloid chanoclavine.pdf

Synthetic biology-based methods (Sbio) and chemical synthesis (Csyn) are two independent approaches that are both widely used for synthesizing biomolecules. In the current study, two systems were combined for the overproduction of chanoclavine (CC), a structurally complex ergot alkaloid. The whole synthetic pathway for CC was split into three sections: enzymatic synthesis of 4-Br-Trp (4-Bromo-trptophan) using cell-lysate catalysis (CLC), chemical synthesis of prechanoclavine (PCC) from 4-Br-Trp, and overproduction CC from PCC using a whole-cell catalysis (WCC) platform. The final titer of the CC is over 3 g/L in this Sbio-Csyn hybrid system, the highest yield reported so far, to the best of our knowledge. The development of such a combined route could potentially avoid the limitations of both Sbio and Csyn systems and boost the overproduction of complex natural products.</p

Chemoenzymatic Hunsdiecker-Type Decarboxylative Bromination of Cinnamic Acids

In this contribution, we report chemoenzymatic bromodecarboxylation (Hunsdiecker-type) of α,ß-unsaturated carboxylic acids. The extraordinarily robust chloroperoxidase from Curvularia inaequalis (CiVCPO) generated hypobromite from H2O2 and bromide, which then spontaneously reacted with a broad range of unsaturated carboxylic acids and yielded the corresponding vinyl bromide products. Selectivity issues arising from the (here undesired) addition of water to the intermediate bromonium ion could be solved by reaction medium engineering. The vinyl bromides so obtained could be used as starting materials for a range of cross-coupling and pericyclic reactions

Vanadium-Containing Chloroperoxidase-Catalyzed Versatile Valorization of Phenols and Phenolic Acids

The downstream product transformation of lignin depolymerization is of great interest in the production of high-value aromatic chemicals. However, this transformation is often impeded by chemical oxidation under harsh reaction conditions. In this study, we demonstrate that hypohalites generated in situ by the vanadium-containing chloroperoxidase from Curvularia inaequalis (CiVCPO) can halogenate various electron-rich and electron-poor phenol and phenolic acid substrates. Specifically, CiVCPO enabled decarboxylative halogenation, deformylative halogenation, halogenation, and direct oxidation reactions. The versatile transformation routes for the valorization of phenolic compounds showed up to 99% conversion and 99% selectivity, with a turnover number of 60,700 and a turnover frequency of 60 s–1 for CiVCPO. This study potentially expands the biocatalytic toolbox for lignin valorization