A reversible photochromic covalent organic framework.

Covalent organic frameworks are a type of crystalline porous materials that linked through covalent bond, and they have numerous potential applications in adsorption, separation, catalysis, and more. However, there are rarely relevant reported on photochromism. Fortunately, a hydrazone-linked DBTB-DETH-COF is rapidly generated through ultrasound method.

Binaphthyl-based chiral covalent organic frameworks for chiral drug separation.

Separation of racemic drugs is of great importance and interest in chemistry and pharmacology. Here, we report the bottom-up synthesis of the binaphthyl-based chiral covalent organic frameworks (CCOFs), (R)-BHTP-COF. Then, high-performance liquid chromatography (HPLC) columns were prepared using (R)-BHTP-COF as a chiral stationary phase (CSP).

[Clinical characteristics of pregnancy complicated with inflammatory bowel disease].

Objective: To analyze the clinical characteristics of patients with inflammatory bowel diseases (IBD) in pre-pregnancy, pregancy and loctation.

Methods: The clinical data of pregnancy complicated with IBD in Department of Obstetrics and Gynecology of Peking University Third Hospital and deli-very from September 2011 to June 2022 were collected. The clinical characteristics of the patients were analyzed retrospectively.

A BINOL-phosphoric acid and metalloporphyrin derived chiral covalent organic framework for enantioselective α-benzylation of aldehydes.

The catalytic asymmetric α-benzylation of aldehydes represents a highly valuable reaction for organic synthesis. For example, the generated α-heteroarylmethyl aldehydes, such as ()-2-methyl-3-(pyridin-4-yl)propanal (()-MPP), are an important class of synthons to access bioactive drugs and natural products. We report herein a new and facile synthetic approach for the asymmetric intermolecular α-benzylation of aldehydes with less sterically hindered alkyl halides using a multifunctional chiral covalent framework (CCOF) catalyst in a heterogeneous way.

Construction of acid-base bifunctional covalent organic frameworks Doebner reaction for catalysing cascade reaction.

We report herein a series of quinoline-4-carboxylic acid linked COFs the multicomponent one-pot Doebner reaction. The obtained acid-base bifunctional COFs are chemically stable and can highly promote one-pot cascade deacetalization-Knoevenagel condensation reaction in a heterogeneous way under solvent-free conditions.

Homochiral Covalent Organic Framework for Catalytic Asymmetric Synthesis of a Drug Intermediate.

()-2-(2-Chlorophenyl)-2-(6,7-dihydrothieno[3,2-]pyridin-5(4)-yl)acetonitrile (()-) is a key intermediate in the synthesis of ()-clopidogrel, which is one of the most saleable worldwide antiplatelet and antithrombotic drugs. We show herein a facile method for the direct synthesis of ()- via Strecker reaction using a homochiral covalent framework catalyst in a heterogeneous way. The asymmetric synthesis involves a photothermal-conversion-triggered, thermally driven reaction which affords ()- in 98% yield with 94% enantiomeric excess under visible-light irradiation.

Homochiral Covalent Organic Frameworks for Asymmetric Catalysis.

Owing to their permanent porosity, highly ordered and extended structure, good chemical stability, and tunability, covalent organic frameworks (COFs) have emerged as a new type of organic materials that can offer various applications in different fields. Benefiting from the huge database of organic reactions, the required functionality of COFs can be readily achieved by modification of the corresponding organic functional groups on either polymerizable monomers or established COF frameworks. This striking feature allows homochiral covalent organic frameworks (HCCOFs) to be reasonably designed and synthesized, as well as their use as a unique platform to fabricate asymmetric catalysts.

Construction of Covalent Organic Frameworks via Three-Component One-Pot Strecker and Povarov Reactions.

Postsynthetic modification (PSM) has been demonstrated to be a powerful method for achieving new covalent organic frameworks (COFs) via single-step or multistep organic functional group transformations on established COF frameworks. PSM, however, might sometimes lead to collapse of the COF framework, decreases in crystallinity, or low postsynthetic yield due to the inherent limit of solid-state synthesis. Herein we report, for the first time, a new synthetic strategy that can generate new COFs via multicomponent one-pot reactions.

Photothermal conversion triggered thermal asymmetric catalysis within metal nanoparticles loaded homochiral covalent organic framework.

For seeking high enantiopurity, the previously reported thermal asymmetric catalysis is usually carried out at low temperature sometimes with limited yield, that is, the high enantiomeric excess (ee) usually at the cost of high yield. Thus, the achieving both high stereoselectivity and yield is an enormous challenge. We report herein two metal nanoparticle (M NP)-loaded and porphyrin-containing homochiral covalent organic framework (CCOF)-based composite catalysts, and their application in the thermally-driven asymmetric one-pot Henry and A-coupling reactions.

Homochiral BINAPDA-Zr-MOF for Heterogeneous Asymmetric Cyanosilylation of Aldehydes.

A new homochiral was prepared by a new chiral organic linker of ()-4,4'-(6,6'-dichloro-2,2'-diethoxyl-[1,1'-binaphthalene]-4,4'-diyl)dibenzoic acid () and ZrCl under solvothermal conditions. Its structure was determined by Pawley refinement on the basis of the measured PXRD pattern determined for , and it showed that the obtained chiral MOF crystallized in the 2 space group with the same topological structure as that of UiO-66. The obtained can be a very active catalyst to catalyze aldehyde cyanosilylation.

Analysis of serum metabolomics among biopsy-proven diabetic nephropathy, type 2 diabetes mellitus and healthy controls.

Type 2 diabetes mellitus (TDM) has a rising prevalence and diabetic nephropathy (DN) is a major complication of TDM. Metabolomics could provide novel insights into the pathogenesis, so we aimed to explore serum metabolomic profiles from DN to TDM. Serum samples were collected from 14 biopsy-proven DNs, 14 age/gender-matched TDMs without renal diseases (DM), 14 age/gender-matched healthy controls (CTRL) and household contacts of DM group (HH).

Understanding the gut-kidney axis among biopsy-proven diabetic nephropathy, type 2 diabetes mellitus and healthy controls: an analysis of the gut microbiota composition.

Aims: Type 2 diabetes mellitus (TDM) has a rising prevalence and gut microbiota involvement is increasingly recognized. Diabetic nephropathy (DN) is a major complication of TDM. The aim of the study was to understand the gut-kidney axis by an analysis of gut microbiota composition among biopsy-proven DN, TDM without kidney disease, and healthy control.

CuL metal-organic cages for A-coupling reactions: reversible coordination interaction triggered homogeneous catalysis and heterogeneous recovery.

The reported Cu(ii) metal-organic cage (Cu3L2, 1) can be a highly active reusable catalyst to homogeneously catalyze the A3-coupling reaction in CHCl3 and can be heterogeneously recovered by simply adding 1,4-dioxane via formation of the insoluble metal-organic framework (Cu3L2(1,4-dioxane)1.5, 2).

Ru Nanoparticles-Loaded Covalent Organic Framework for Solvent-Free One-Pot Tandem Reactions in Air.

Condensation of benzene-1,3,5-tricarbohydrazide with benzene-1,4-dicarboxaldehyde generated a new covalent organic framework, COF-ASB (1), in which the organic units are held together via hydrazone linkage to form porous frameworks. COF-ASB (1) is highly crystalline and displays good chemical and thermal stability and is permanently porous. In addition, 1 can be an ideal support to load Ru nanoparticles (Ru NPs) to generate Ru@COF-ASB (2).

Dual Heterogeneous Catalyst Pd-Au@Mn(II)-MOF for One-Pot Tandem Synthesis of Imines from Alcohols and Amines.

A new Mn(II) metal-organic framework (MOF) 1 was synthesized by the combination of 4,4,4-trifluoro-1-(4-(pyridin-4-yl)phenyl)butane-1,3-dione (L) and Mn(OAc) in solution. 1 features a threefold-interpenetrating NbO net containing honeycomb-like channels, in which the opposite Mn(II)···Mn(II) distance is 23.5075(10) Å.

Au@Cu(II)-MOF: Highly Efficient Bifunctional Heterogeneous Catalyst for Successive Oxidation-Condensation Reactions.

A new composite Au@Cu(II)-MOF catalyst has been synthesized via solution impregnation and full characterized by HRTEM, SEM-EDS, XRD, gas adsorption-desorption, XPS, and ICP analysis. It has been shown here that the Cu(II)-framework can be a useful platform to stabilize and support gold nanoparticles (Au NPs). The obtained Au@Cu(II)-MOF exhibits a bifunctional catalytic behavior and is able to promote selective aerobic benzyl alcohol oxidation-Knoevenagel condensation in a stepwise way.

Developing multi-cellular tumor spheroid model (MCTS) in the chitosan/collagen/alginate (CCA) fibrous scaffold for anticancer drug screening.

In this work, a 3D MCTS-CCA system was constructed by culturing multi-cellular tumor spheroid (MCTS) in the chitosan/collagen/alginate (CCA) fibrous scaffold for anticancer drug screening. The CCA scaffolds were fabricated by spray-spinning. The interactions between the components of the spray-spun fibers were evidenced by methods of Coomassie Blue stain, X-ray diffraction (XRD) and Fourier transform-infrared spectroscopy (FTIR).