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101.
Research on Chemical Intermediates - A simple and facile synthesis of highly functionalized quinazoline derivatives has been successfully developed by treatment of aldehydes, ammonium acetate, and... 相似文献
102.
Seyed Meysam Baghbanian Yaser Babajani Hamed Tashakorian Samad Khaksar Maryam Farhang 《Comptes Rendus Chimie》2013,16(2):129-134
In this work, a green, simple and highly efficient procedure for the synthesis of bis(indolyl)methanes is described. The condensation of indoles catalyzed by p-sulfonic acid calix[4]arene in water and under solvent-free conditions afford the title compounds in high yields and relatively short reaction times. 相似文献
103.
Fatemeh JahaniMahmood Tajbakhsh Hamid GolchoubianSamad Khaksar 《Tetrahedron letters》2011,52(12):1260-1264
A simple and efficient method for the chemoselective N-Boc protection of the amine moiety in a variety of compounds is described using di-tert-butyl dicarbonate and guanidine hydrochloride as an organocatalyst in ethanol at 35-40 °C. Selective mono-N-Boc protection of diamines and chemoselective protection of hydroxylamines without formation of any side products is achieved. Amino acids and peptides are N-Boc protected efficiently in excellent yields under convenient reaction conditions. 相似文献
104.
The volatile constituents obtained by hydrodistillation of the aerial parts of Prangos coryombosa at the vegetative and flowering stages were analysed by GC and GC-MS. Twenty-one and 28 compounds were identified from the oils obtained from the plant's aerial parts at the vegetative and flowering stages, respectively. The oil from the vegetative stage was dominated by β-elemene (22%) and spathulenol (12.5%), whereas the oil from the flowering period was characterised by β-elemene (40.7%) and kessane (10.7%). The main compounds of the oil at the flowering stage were isolated by TLC and their structures were elucidated by (1)H and (13)C NMR. The results have ecological and taxonomical significance. 相似文献
105.
Mohidus Samad Khan Deniece Fon Xu Li Junfei Tian John Forsythe Gil Garnier Wei Shen 《Colloids and surfaces. B, Biointerfaces》2010,75(2):441-447
The feasibility of thermal ink jet printing as a robust process for biosurface engineering was demonstrated. The strategy investigated was to reconstruct a commercial printer and take advantage of its colour management interface. High printing resolution was achieved by formulating bio-inks of viscosity and surface tension similar to those of commercial inks. Protein and enzyme denaturation during thermal ink jet printing was shown to be insignificant. This is because the time spent by the biomolecules in the heating zone of the printer is negligible; in addition, the air and substrate of high heat capacity absorb any residual heat from the droplet.Gradients of trophic/tropic factors can serve as driving force for cell growth or migration for tissue regeneration. Concentration gradients of proteins were printed on scaffolds to show the capability of ink jet printing. The printed proteins did not desorb upon prolonged immersion in aqueous solutions, thus allowing printed scaffold to be used under in vitro and in vivo conditions. Our group portrait was ink jet printed with a protein on paper, illustrating that complex biopatterns can be printed on large area. Finally, patterns of enzymes were ink jet printed within the detection and reaction zones of a paper diagnostic. 相似文献
106.
Twenty one new chromophoric chain β‐substituted polymethine asycyanine (CCBSPA) colorants have been synthesised by catalytic condensation of (i) 4‐dimethylaminophenylbutadientylphenyl ketone; (ii) 4‐dimethylbutadienyl‐4‐nitrophenyl ketone; and (iii) 4‐dimethylaminophenylbutadienyl‐4‐methyl‐phenyl ketone with 2‐methyl quinoline methiodide and 2‐methyl‐6‐substituted quinoline methiodides using piperidine as catalyst & ethanolic DMF as solvent. These colorants were synthesized with the object to study the impact of various functional groups and chain lengthening on visible electronic spectra. All the colorants showed increase in electronic spectra whether electron withdrawing or donating. These colorants also absorb at higher wavelengths when compared to the previously reported butadienylene chain asycyanino‐colorants. 相似文献
107.
Trifluoroethanol was used as a reusable catalyst and medium for the ring opening of epoxides using aliphatic and aromatic amines as nucleophile under mild conditions to give the corresponding β-amino alcohols in high yields and regioselectivity. 相似文献
108.
Samad Khaksar Akbar Heydari Seyed Mohammad Vahdat 《Journal of fluorine chemistry》2010,131(12):1377-1381
A simple, inexpensive, environmentally friendly and efficient route for the synthesis of benzimidazole and formamidine derivatives by the reaction of O-phenylenediamines or amines with orthoesters using hexafluoroisopropanol as a solvent/catalyst is described. 相似文献
109.
Antifungal activity of methanolic extracts of leaves of three tree species, namely Azadirachta indica L., Syzygium cumini (L.) Skeels. and Melia azedarach L. was evaluated against two strains of Alternaria alternata, isolated from dying-back trees of two Eucalyptus spp., namely Eucalyptus citriodora and Eucalyptus globulus. All the concentrations (1,?2,?…?,?5% w/v) of the methanolic extracts of the three tree species significantly reduced the fungal biomass. There were reductions in the ranges 82-88%, 88-96% and 83-96% in the biomass of A. alternata strains due to different concentrations of the leaf extracts of S. cumini, A. indica and M. azedarach, respectively. Methanolic extract of M. azedarach was subjected to further fractionation using n-hexane, chloroform, ethyl acetate and n-butanol successively in the order of increasing polarity. Aqueous and n-butanol fractions gave promising results in the significant decrease in fungal biomass. This study concludes that aqueous and n-butanol fractions of methanolic leaf extract of M. azedarach can be used as biofungicides for the management of A. alternata. 相似文献
110.
Trifluoroethanol is found to be an efficient and recyclable medium in promoting one-pot, three-component coupling reactions of aldehydes or ketones, amines and trimethylsilyl cyanide or trimethyl phosphite to afford the corresponding α-amino nitriles or α-amino phosphonates in high yields. This protocol does not require the use of an acid or base catalyst. 相似文献