A5064613451- Asymmetric Synthesis and Catalysis
- Asymmetric Hydrogenation and Catalysis
- Synthetic Organic Chemistry Methods
- Synthesis and Catalytic Reactions
- Chemical Synthesis and Reactions
- Carbohydrate Chemistry and Synthesis
- Cyclopropane Reaction Mechanisms
- Glycosylation and Glycoproteins Research
- Mycobacterium research and diagnosis
- Hepatitis C virus research
- Hepatitis B Virus Studies
- Monoclonal and Polyclonal Antibodies Research
- Tuberculosis Research and Epidemiology
- Vanadium and Halogenation Chemistry
- Natural Fiber Reinforced Composites
- Sulfur-Based Synthesis Techniques
- Polymer Nanocomposites and Properties
- Polymer crystallization and properties
- Phosphorus compounds and reactions
- Organoboron and organosilicon chemistry
- Biochemical and biochemical processes
- Fire dynamics and safety research
- Fatigue and fracture mechanics
- Non-Destructive Testing Techniques
- Supramolecular Self-Assembly in Materials
Jiangsu University of Science and Technology
2024
University of Alberta
2014-2022
Guizhou University
2022
Alberta Glycomics Centre
2017-2018
Sichuan University
2006-2012
Ingenierie des Materiaux polymeres
2011
Institute of Basic Medical Sciences of the Chinese Academy of Medical Sciences
2003
Chinese PLA General Hospital
2003
University of Hong Kong
2003
Shaanxi Research Association for Women and Family
2000
The enantioselective synthesis of 3-functionalized oxindole derivatives has experienced an explosive development. This minireview introduces the recent application rare earth (RE) metal complex catalysts in targeted frameworks. direct addition reactions 3-substituted oxindoles or isatins are described, together with a discussion catalytic mechanism and related transformations to pharmaceuticals.
The first catalytic enantioselective Roskamp reaction of alpha-alkyl-alpha-diazoesters with aromatic aldehydes was realized using a simple chiral N,N'-dioxide-scandium(III) complex. Remarkably, 0.05 mol % catalyst, the performed well over series substrates, giving desired products chemoselectively in excellent yields (up to 99%) and enantioselectivities 98% ee) under mild conditions. This protocol provides promising method for synthesis alpha-alkyl-beta-keto esters 1,3-diols.
Sc takes action: The highly enantioselective hydroxyamination reaction of N-unprotected 2-oxindoles with nitrosoarenes has been realized using the Sc(OTf)3/L1 complex. catalyst system exhibited remarkably broad substrate scope and high efficiency. This transformation is first example a chiral ScIII/enolate activating nitrosoarene, can be conducted on gram scale without loss in ee values. Detailed facts importance to specialist readers are published as "Supporting Information". Such documents...
The only currently commercialized point-of-care assay for tuberculosis (TB) that measures lipoarabinomannan (LAM) in urine (Alere LF-LAM) has insufficient sensitivity. We evaluated the potential of 100 novel monoclonal antibody pairs targeting a variety LAM epitopes on sensitive electrochemiluminescence platform to improve diagnostic accuracy. In screening, many showed high reactivity purified but performed poorly at detecting urinary clinical samples, suggesting differences antigen...
A highly enantioselective alpha-amination of 3-substituted oxindoles with azodicarboxylates catalyzed by a chiral Sc(OTf)(3)/N,N'-dioxide complex (Tf: triflate) has been developed and affords the corresponding 3-amino-2-oxindole derivatives in high yields (up to 98%) excellent enantioselectivities 99% ee). The procedure is capable tolerating relatively wide range substrates, results (92-96% ee) can also be obtained, even presence 0.5 mol % catalyst loading under mild conditions. These showed...
Abstract Asymmetric catalysis : A facile enantioselective Strecker reaction of ketimines with trimethylsilyl cyanide (TMSCN) was realized by employing chiral ( S )‐BNPNa 3 e and PBAP as an additive (see image). wide substrate scope good‐to‐excellent enantioselectivities were achieved. magnified image efficient catalyzed a alkali‐metal salt has been developed. When 10 mol % BNPNa (BNP=1,1′‐binaphthyl‐2,2′‐diylphosphate) prepared in situ para ‐ tert ‐butyl‐ ortho ‐adamantylphenol (PBAP)...
Full investigation of cyanation aldehydes, ketones, aldimines and ketimines with trimethylsilyl cyanide (TMSCN) or ethyl cyanoformate (CNCOOEt) as the source has been accomplished by employing an in situ generated catalyst from cinchona alkaloid, tetraisopropyl titanate [Ti(OiPr)(4)] achiral modified biphenol. With TMSCN source, good to excellent results have achieved for Strecker reaction N-Ts (Ts=p-toluenesulfonyl) (up >99% yield ee) well ketones 99% 98% ee). By using CNCOOEt alternative...
An array of homogeneous glycans representing all the major carbohydrate structures present in cell wall human pathogen Mycobacterium tuberculosis and other mycobacteria has been probed with a panel glycan-binding receptors expressed on cells mammalian innate immune system. The results provide an overview interactions between mycobacterial that mediate uptake survival macrophages, dendritic cells, sinusoidal endothelial cells. A subset wide variety glycan surfaces interact system through...
Abstract Lipoarabinomannan (LAM), the major antigenic glycolipid of Mycobacterium tuberculosis, is an important immunodiagnostic target for detecting tuberculosis (TB) infection in HIV-1–coinfected patients, and believed to mediate a number functions that promote disease development. To probe human humoral response against LAM during TB infection, several novel LAM-specific mAbs were molecularly cloned from memory B cells isolated infected patients grown vitro. The fine epitope specificities...
A direct catalytic asymmetric aldol-type reaction of 3-substituted-2-oxindoles with glyoxal derivatives and ethyl trifluoropyruvate, catalyzed by a chiral N,N'-dioxide-Sc(OTf)(3) (Tf = trifluoromethanesulfonyl) complex, has been developed that tolerates wide range substrates. The proceeds in good yields excellent enantioselectivities (up to 93% yield, 99:1 diastereomeric ratio (dr), >99% enantiomeric excess (ee)) under mild conditions, deliver 3-(alpha-hydroxy-beta-carbonyl) oxindoles...
A simple and highly efficient N,N'-dioxide organocatalyst system was developed for the asymmetric alpha-chlorination of cyclic beta-ketoesters using easily available NCS as chlorine source to provide a series optically active alpha-chloro-beta-ketoesters in excellent yields with 90-98% ee.
Highly enantioselective synthesis of 1,3-bis(hydroxymethyl)-2-oxindoles was established through chiral NdIII-N,N′-dioxide in up to 93% yield and >99% ee under mild conditions. The key features this approach include using cheap readily available formalin as a hydroxymethylation C1 unit unprotected 3-substituted-2-oxindoles nucleophiles directly. initial C-aldol product from 3-substituted-2-oxindole converted the corresponding 1,3-bis(hydroxymethyl)-2-oxindole derivative immediately reaction...
Sc übernimmt: Die hoch enantioselektive Hydroxyaminierung von N-ungeschützten 2-Oxindolen mit Nitrosoarenen gelang dem Komplex aus Sc(OTf)3 und L1, wobei die Substratbreite Effizienz erstaunlich waren. Es handelt sich um das erste Beispiel für Aktivierung eines Nitrosoarens durch ein chirales ScIII-Enolat. Auch Umsetzungen im Gramm-Maßstab sind ohne eine Verschlechterung der ee-Werte möglich. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such...
Abstract Intumescent systems have been developed since many years for a wide range of applications, even if they are mainly used in coatings nowadays. The objective this paper is to determine the intumescent concept can be applied highly filled reinforced polypropylene (PP) composites containing talc. Formulations that meet electrical industry requirements developed, it has observed addition talc into PP leads decrease fire retardancy systems. A thermal stabilization material noted at high...
A number of biologically relevant glycoconjugates possess 1,2-cis-furanosidic linkages, a class glycosidic bond that remains challenging to introduce with high stereoselectivity. In this paper, we report an approach one family such α-xylofuranosides, via the use thioglycoside donors possessing conformationally restricting xylylene protecting group. The method was shown provide desired targets in good excellent yield and Computational investigations support proposal group locks electrophilic...
Two chiroptical spectroscopic techniques, namely, electronic and vibrational circular dichroism (ECD VCD), as well NMR spectroscopy have been utilized to determine the absolute configurations geometries of two Fráter-Seebach alkylation reaction products with long hydrocarbon chains. The experimental studies complemented density functional theory calculations. Strong characteristic bisignate VCD signatures in carbonyl stretching region observed for both compounds film state. Truncated models,...
The outer surfaces of mycobacteria, including the organism that causes tuberculosis, are decorated with an array immunomodulatory glycans. Among these lipooligosaccharides (LOSs), a class molecules for which function remains poorly understood. We describe chemical synthesis glycan portion tridecasaccharide LOS from opportunistic pathogen Mycobacterium kansasii. target contains number unusual structural motifs complicate its assembly and is most complex mycobacterial to be synthesized date...
The effect of high–molecular-weight polyethylene (HMWPE) on crystal morphology was investigated for high-density (HDPE) through dynamic packing injection molding (DPIM). With the aid differential scanning calorimetry (DSC), wide-angle x-ray diffraction (WAXD), and electron microscopy (SEM) measurements, a typical web-like shish kebab morphology, which markedly increases stiffness toughness, found in HMWPE-induced samples DPIM. SEM results show that much better structure, most lamellae...
A route for preparing lipooligosaccharide (LOS) glycans from Mycobacterium tuberculosis Canetti was developed and applied to the most complex of these structures, LOS II. The synthesis target nonasaccharide achieved via a convergent [3+3+3] approach. Key features strategy include stereoselective an asymmetrically substituted trehalose moiety two protected glucose residues several chemoselective glycosylations involving thioglycoside donors.
A bifunctional titanium catalyst system has been developed for the asymmetric direct-type aldol reaction of ethyl diazoacetate with aldehydes, which produced desired products in good yields (up to 83%) excellent enantioselectivities 94% ee). wide range aromatic, heteroaromatic and aliphatic aldehydes were found be suitable substrates presence (S)-BINOL (5 mol%), cinchonine Ti(Oi-Pr)4 mol%) H2O (15 mol%). On basis experimental results previous reports, a possible working model proposed...