We report herein a photoinduced radical 1,3-dipolar cycloaddition between the 2-benzothiazolimines and tetrahydroisoquinoline derivatives with an organo-photocatalyst. A variety of benzothiazole-based hexahydroimidazo[2,1-]isoquinoline architectures with great synthetic value were conveniently and efficiently constructed in moderate to good yields and excellent diastereoselectivities with highly tolerant functional groups. Moreover, the practicality and utility of this protocol were demonstrated by scale-up synthesis and facile elaboration.
View Article and Find Full Text PDFHerein, we present an attractive organocatalytic asymmetric addition of P-nucleophiles to five-membered cyclic -sulfonyl imines facilitated by phosphonium salt catalysis, enabling the highly enantioselective synthesis of tri- and tetra-substituted cyclic phosphorus-containing benzosultams. With this protocol, various cyclic α-aminophosphonates were efficiently synthesized with high yields and exceptional enantioselectivities (up to >99% ee) under mild reaction conditions. The utility and practicality of this method were demonstrated through gram-scale reactions and straightforward elaborations.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2024
The stereochemistry of shape-persistent molecular cages, particularly those resembling prisms, exerts significant influence on their application-specific functionalities. Although methods exist for fabricating inherently chiral prism-like cages, strategies for catalytic asymmetric synthesis of these structures in a diversity-oriented fashion remain unexplored. Herein, we introduce an unprecedented organocatalytic desymmetrization approach for the generation of inherently chiral prism-like cages via phosphonium-containing foldamer-catalyzed SAr reactions.
View Article and Find Full Text PDFDurian peel, an abundant waste in Malaysia could be a potential substrate for fermentable sugar recovery for value-added biochemical production. Common pretreatment such as acid or alkaline pretreatment resulted in the need for extensive solid washing which generated wastewater. Herein, this study aims to introduce sonication on top of chemical pretreatment to destruct lignin and reduce the chemical usage during the durian peel pretreatment process.
View Article and Find Full Text PDFNickel-iron doped granular activated carbon (GAC-N) was used to enhance immobilization in biohydrogen production. The effect of the sludge ratio to GAC-N, ranged 1:0.5-4, was studied.
View Article and Find Full Text PDFA novel protocol of gold-catalyzed -aryl propargylamines to construct tetrahydroquinolines and 5,6-dihydro-4-pyrrolo[3,2,1-ij]quinolines in moderate to good yields has been developed through the tandem reactions of intramolecular hydroarylation and transfer hydrogenation. The strategy has the advantages of easy access to raw materials, simple reaction conditions, good substrate compatibility, high efficiency, and excellent regioselectivity.
View Article and Find Full Text PDFThe aim of this study was to establish an improved pretreatment and fermentation method i.e. immobilized cells for high recovery of fermentable sugars from palm kernel cake (PKC) and its effects on fermentability performance by Actinobacillus succinogenes 130Z in the conversion of the fermentable sugar to lactic acid.
View Article and Find Full Text PDFGiven the comparatively lower rotational barriers, the catalytic asymmetric construction of axially chiral biaryl structures, especially those containing a five-membered heterocycle, still remains a challenge. Herein, we described a general and modular protocol to access atropisomeric arylpyrazole scaffolds containing a phosphorus unit by a dipeptide phosphonium salt catalyzed reaction involving an oxidative central-to-axial chirality conversion. This reaction features excellent yields and enantioselectivities, broad substrate scope, and a low catalyst loading, delivering axially chiral phosphine compounds.
View Article and Find Full Text PDFObjective: To investigate the effects of sacubitril/valsartan (S/V) on cardiopulmonary function and blood pressure response to exercise during hospitalization in patients with acute myocardial infarction (AMI) based on the cardiopulmonary exercise test (CPET).
Methods: A total of 265 AMI patients were treated with either perindopril or S/V within 24 hours of admission. CPET was completed for all patients before discharge.
Optically pure pseudo-natural products (PNPs), particularly exemplified by azabicyclo[3.3.1]nonane molecules and their analogs provide an attractive platform for structure-activity relationship studies, and also lead new compound discovery in drug development.
View Article and Find Full Text PDFIn this paper, a method of intelligent identification and data smooth processing of flying flexible joint pivoting center based on machine vision is proposed. The intelligent identification is realized by the following process: first of all the geometric center of the two markers attached to the flying body is located on a straight line at a certain angle to the center-line of the measured pivoting body, secondly then continuous image sampling is carried out by industrial camera when the marker swings with the pivoting body, and image data is transmitted through a data interface to an industrial computer, Finally the image processing module de-noises the image, removes the background and locates the markers to obtain the plane coordinates of the markers in the coordinate system of the test system. The data smooth of obtained coordinates is carried outby Matlab software including the following steps: the coordinates of the mark points detected based on machine vision are optimized to obtain the smooth curve by fitting of the parabola and arc.
View Article and Find Full Text PDFA highly enantiodivergent organocatalytic method is disclosed for the synthesis of atropisomeric biaryls via kinetic resolution inspired by a dipeptide-phosphonium salt-catalyzed Atherton-Todd (A-T) reaction. This flexible approach led to both R- and S-enantiomers by fine-tuning of bifunctional phosphonium with excellent selectivity factors (s) of up to 1057 and 525, respectively. The potential of newly synthesized O-phosphorylated biaryl diols was illustrated by the synthesis of axially chiral organophosphorus compounds.
View Article and Find Full Text PDFThis study aimed to enhance the crystallizability of bio-based succinic acid for its efficient recovery while maintaining the end product at the highest purity. Immobilization of Actinobacillus succinogenes was initially evaluated based on three different carriers: volcanic glass, clay pebbles, and silica particles. The adsorption capacity of metabolites with a low concentration (10 g/L) and a high concentration (40 g/L) was investigated.
View Article and Find Full Text PDFIn order to perceive the state of the process of reverse thinning spinning of the ultra-thin wall tube, a monitoring method based on drum shape is proposed. The method uses the non-uniform rational basis spline curve fitting method based on the moving least squares method to reconstruct the outer contour data of the spinning zone collected by the line laser displacement sensor and extracts the outer contour curve of the drum zone according to the spinning characteristics. Then, the dynamic time warping algorithm is used to analyze the similarity between the current and previous drum curves in order to judge whether the current spinning state is abrupt or not.
View Article and Find Full Text PDFA highly diastereo- and enantioselective [4 + 1] cycloaddition of -quinone methides to α-halogenated ketones was realized by bifunctional phosphonium salt catalysis, furnishing functionalized 2,3-dihydrobenzofurans in high yields and excellent stereoselectivities (>20:1 and up to >99.9% ee). Mechanistic observations suggested that the reaction underwent a cascade intermolecular substitution/intramolecular 1,6-addition process.
View Article and Find Full Text PDFShanghai Kou Qiang Yi Xue
June 2019
A catalyst-free decarboxylative reaction between β-keto acids and 2H-chromene acetals in water was developed. This reaction featured a broad substrate scope and easily obtainable starting materials to afford α-functionalized 2H-chromenes in high yields. The synthetic value of this protocol was also demonstrated by the scale-up synthesis and versatile conversions of the title product into other useful compounds.
View Article and Find Full Text PDFContinuous bio-production of succinic acid was reported in homogeneous solid dispersion (HSD) system utilizing porous coconut shell activated carbon (CSAC) as immobilization carrier. The aim of the present work was to implement the HSD system to increase the area of cell immobilization and the rate of succinic-acid production from the lignocellulosic medium. The ratio of the two enzymes (cellulase-to-hemicellulase) was initially optimized to break down the lignocellulose into its free monomers, wherein the best ratio was determined as 4:1.
View Article and Find Full Text PDFCalcium carbonate was evaluated as a replacement for the base during the fermentation of glycerol by a highly productive strain of 1,3-propanediol (PDO), viz., Clostridium butyricum JKT37. Due to its high specific growth rate (µ=0.
View Article and Find Full Text PDFZhongguo Shi Yan Xue Ye Xue Za Zhi
June 2016
Objective: To investigaate the clinical efficacy of Aidi injection-asisted R-CHOP chemotherapy for the treatment of diffuse large B-cell lymphoma (DLBCL).
Methods: Fifty-one patients diagnosed as DLBCL in our department from February 2005 to September 2015 were randomly divided into 2 groups. Out of them, 26 patients in one group received R-CHOP chemotherapy asisted by Aidi intravenous infection (Aidi+R-CHOP group), 25 patients were in another group received only R-CHOP chemotherapy (R-CHOP group), 3 weeks for one course, to tally continuous 2 courses.
Zhonghua Yi Xue Za Zhi
July 2013
Objective: To assess the changes in coagulation, thrombosis, anti-coagulation and fibrinolysis during early pregnancy.
Methods: A total of 105 gravidas with monocytic pregnancies between 10 and 12 weeks gestational age at Sun Yat-sen Memorial Hospital, Sun Yat-sen University during April 2005 to June 2009 were recruited for study group and another 82 non-pregnant women as control group. Coagulation parameters, including thrombin time (TT), activated partial thromboplastin time (APTT), prothrombin (PT) and fibrinogen (Fg), were measured.
Objective: To evaluate the effects of low molecular weight heparin (LMWH) and heparin-binding epidermal growth factor (HB-EGF) on the biological function of human trophoblast in first trimester.
Methods: From Feb. 2011 to Nov.
Acta Crystallogr Sect E Struct Rep Online
January 2013
In the title compound, [PdBr(C17H17N2O5)], the Pd(II) atom is coordinated by an N,C(1),N'-tridentate pincer ligand and a Br atom in a distorted square-planar geometry. In the crystal, mol-ecules are connected by C-H⋯Br and C-H⋯O hydrogen bonds, and π-π inter-actions between the oxazole and benzene rings [centroid-centroid distance = 3.7344 (19) Å], resulting in a three-dimensional supra-molecular structure.
View Article and Find Full Text PDFBis(thiazole) pincer palladium complexes showed efficient catalytic activity for the Suzuki-Miyaura coupling of aryl halides, allowing the synthesis of biaryls with very high turnover numbers and turnover frequencies. The complexes were successfully applied in the scalable and green synthesis of the key intermediates of bioactive LUF5771 and its analogues.
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