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11.
Herein, two unit of β-cyclodextrin linked by thiomethylene bridge was synthesized and employed as a novel efficient supramolecular host for the synthesis of biologically active chromenones templates via three-component single-pot reaction. A possible reaction mechanism through molecular complexation is suggested based on 2D ROESY NMR spectroscopic analysis. Moreover, the catalyst could be easily recycled, while a 94% yield and 89% rate of catalyst recovery could be achieved after four cycles of catalyst recycling. Environmentally benign reaction conditions, excellent yields, and avoidance of organic solvent and conventional isolation as well as purification are the noteworthy credits of this developed protocol. 相似文献
12.
Suresh Babu Meruva Raghavendra Rao K. Aaseef Mohammed Vilas H. Dahanukar U. K. Syam Kumar P. K. Dubey 《合成通讯》2016,46(2):187-196
A concise and enantioselective syntheses of antileukemic natural products such as (–)-(S)-goniothalamin and (–)-leiocarpin A has been accomplished in excellent yields. By employing reported conditions on suitable substrates via Julia–Kocienski olefination, intramolecular lactonization, and subsequently dehydroxylative olefination, (–)-(S)-goniothalamin was synthesized. Then Sharpless asymmetric dihydroxylation–intramolecular Michael addition on (–)-(S)-goniothalamin provided (–)-leiocarpin A. 相似文献
13.
Kiran F. Shelke Suryakant B. Sapkal Kirti S. Niralwad Bapurao B. Shingate Murlidhar S. Shingare 《Central European Journal of Chemistry》2010,8(1):12-18
A green, mild and efficient method for Knoevenagel condensation of 3-formylchromone/2-chlroquinoline-3-carbaldehyde with active
methylene compounds such as Meldrum’s acid/ethyl cyanoacetate using biosupported cellulose sulphuric acid (CSA) in the solid-state
by grinding under solvent-free condition has been developed. This method provides several advantages including environmental
friendliness, shor t reaction times, high yields and a simple work-up procedure. Moreover, the CSA was successfully reused
for four cycles without significant loss of activity. 相似文献
14.
Das MR Sarma RK Saikia R Kale VS Shelke MV Sengupta P 《Colloids and surfaces. B, Biointerfaces》2011,83(1):16-22
A solution-based approach to the synthesis of silver (Ag) nanoparticles by chemical reduction of AgNO(3) in a graphene oxide (GrO) suspension is demonstrated. X-ray diffraction and transmission electron microscopy indicate that the Ag nanoparticles, of size range 5-25nm, were decorated on the GrO sheets. The size and shape of the Ag nanoparticles are dependent on the concentration of the AgNO(3) solution. Antimicrobial activity of such hybrids materials is investigated against the Gram negative bacteria Escherichia coli and Pseudomonous aeruginosa. The bacterial growth kinetics was monitored in nutrient broth supplemented with the Ag nanoparticle-GrO suspension at different conditions. It was observed that P. aeruginosa is comparatively more sensitive to the Ag nanoparticle-GrO suspension. 相似文献
15.
The synthesis of 2,4,6-tris[(4-iodo)phenoxy)]-1,3,5-triazine 6, as a new recyclable nonpolymeric analogue of iodobenzene is achieved using the reaction of 2,4,6-trichloro-1,3,5-triazine with 4-iodophenol in the presence of KOH. The application of 6 as a recyclable ‘iodoarene’ is demonstrated for α-tosyloxylation of enolizable ketones via in situ generation of hypervalent iodine(III) species using PTSA and MCPBA as the terminal oxidant. The recyclability of the reagent 6 was possible owing to the facile recovery and reuse from the reaction mixture due to its near insolubility in methanol. 相似文献
16.
Synthesis and Antimicrobial Activities of Novel Series of 3‐(4‐(2‐substituted thiazol‐4‐yl)phenyl)‐2‐(4‐methyl‐2‐substituted thiazol‐5‐yl)thiazolidin‐4‐one Derivatives 下载免费PDF全文
Shivaji H. Shelke Pravin C. Mhaske Sachin Narkhade Vivek D. Bobade 《Journal of heterocyclic chemistry》2014,51(4):1151-1156
In the present investigation, a novel series of 3‐(4‐(2‐substituted thiazol‐4‐yl)phenyl)‐2‐(4‐methyl‐2‐substituted thiazol‐5‐yl)thiazolidin‐4‐one derivatives were synthesized by condensation of 2‐substituted‐4‐methylthiazole‐5‐carbaldehyde with 4‐(2‐substituted thiazol‐4‐yl)benzenamine followed by cyclo‐condensation with thioglycolic acid in toluene. All the newly synthesized compounds were characterized by spectral (IR, 1H NMR, 13C NMR, and Mass) methods. The title compounds were screened for quantitative antibacterial activity (minimal inhibitory concentration). All compounds 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h and 8a , 8b , 8c , 8d , 8e , 8f , 8g , 8h show moderate to good antimicrobial activity, whereas compounds ( 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h ) also show moderate antifungal activity. 相似文献
17.
18.
Lav R. Khot Vilas M. Salokhe H.P.W. Jayasuriya H. Nakashima 《Journal of Terramechanics》2007,44(6):429-437
The deformation behaviour of the soil during dynamic wheel–soil interaction was studied by using the discontinuum modelling technique, distinct or discrete element method (DEM). The simulation model was developed using DEM for two types of soil, soil-A (coarse sand) and soil-B (medium sand). A transparent sided soil bin was used to observe the soil deformation. Three CCD video camera photographic images of the validation experiments were analyzed and compared with the simulation program results.This paper presents the simulation and validation results for two types of soil at three different vertical loadings of 4.9, 9.8 and 14.7 N. Wheel sinkage, vertical and horizontal draft force acting on the rigid wheel and the soil deformation images from the validation experiments were some of the data used to compare the simulation program results with the validation experiments. The simulation program was helpful to understand the complex deformation behaviour of the soils. The simulated results for the deformation behaviour of soil-B showed better correlation with the validation experiments than soil-A. The results obtained have also been compared with the previous work on DEM to explain phenomena such as the high simulated sinkage of the rigid wheel. 相似文献
19.
Vilas D. Athawale 《Journal of Dispersion Science and Technology》2013,34(5):646-653
Alkyd acrylic hybrid emulsions can offer cost/performance advantages over common 1K coatings such as polyurethane dispersions (PUDs), acrylic emulsions and blends. Hybrid emulsions with different ratios of alkyd resin to acrylic monomers were synthesized. Emulsion with resin-to monomer ratio of 1:1 (wt/wt) with total solids as high as 50% had a shelf stability of more than 8 months. Morphology of hybrid emulsions was studied by scanning electron microscopy. Hybrid emulsions were characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis. Films obtained from the hybrid emulsions were found to be homogeneous and exhibited excellent thermal and coating properties. 相似文献
20.