نتایج جستجو برای: pot procedure
تعداد نتایج: 629235 فیلتر نتایج به سال:
TiCl4-promoted aldol reaction of ketones as aldol acceptors followed by elimination of the titanoxy group from the Ti-aldolates affords β,β-disubstituted α,β-unsaturated carbonyl compounds in a one-pot procedure. The use of additives, such as DMF, N,N,N',N'-tetramethylethylenediamine, and pyridine, in the elimination step was found to be important.
2-Substituted azetidin-3-ones can be prepared in good yields and enantioselectivities (up to 85% ee) by a one-pot procedure involving the metalation of the SAMP/RAMP hydrazones of N-Boc-azetidin-3-one, reaction with a wide range of electrophiles, including alkyl, allyl, and benzyl halides and carbonyl compounds, followed by hydrolysis using oxalic acid.
Oximes and diynes undergo efficient cycloaddition in the presence of a catalytic amount of a cationic rhodium(I)/dppf complex (see scheme). Spontaneous dehydration of the initially formed cycloadducts leads to the formation of a variety of substituted pyridines in moderate to good yields. The transformation could also be achieved in a one-pot procedure using aldehydes.
The first examples of cis-configured diborenes - and the first cyclic diborenes - are isolated by taking advantage of stabilisation by chelating diphosphine ligands. The diborenes are prepared by a convenient one-pot reductive procedure that circumvents the need for a pre-formed base-adduct of the boron-containing precursor.
A mild and practically-convenient one-pot procedure for the direct beta-substitution of enones has been developed using a conjugate addition-oxidation strategy with a full range of copper-based reagents and N-tert-butylphenylsulfinimidoyl chloride; alkyl- and aryl-substituted enones are delivered in good to excellent yields.
An expeditious, one-pot method for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones using a mixture of phosphorus pentoxide-methanesulfonic acid (Eaton's reagent) at room temperature under solvent-free conditions is described. The salient features of this method include short reaction time, green aspects, high yields, and simple procedure.
Conversion of carboxylic acids into acid azides using peptide coupling agents, EDC and HBTU is described. The procedure is efficient, practical and applicable to a diverse range of carboxylic acids including N-protected amino acids. Using the same reagents, one-pot synthesis of ureas, dipeptidyl urea esters and carbamates from acids has also been achieved.
Novel luminescent silver nanoclusters (AgNCs) were synthesized utilizing DNA as templates by a simple, rapid and one-pot procedure. Luminescence studies indicated that these DNA-AgNCs exhibited strong emission with peak maximum at 624 nm. The fluorescence of the DNA-AgNCs was found to be quenched by Cu(2+) enabling its detection with high sensitivity and selectivity.
One-pot synthesis of heterocycles having a nitromethyl group was achieved by sequential steps that involved chloronitration of alkenes using iron(III) nitrate nonahydrate followed by elimination and intramolecular Michael addition. This reaction provides an efficient method for the synthesis of heterocycles due to the simple experimental procedure and the use of inexpensive reagents of low toxi...
nano silica sulfuric acid catalyzed synthesis of 2-substituted aryl (indolyl) kojic acid derivatives
nano silica sulfuric acid as a solid acid, was described to be an effective catalyst for one-pot three-component reaction of kojic acid, aryl aldehydes and indoles for the preparation of 2-substituted aryl (indolyl) kojic acid derivatives. the catalyst was prepared by combination of chlorosulfonic acid to nano silica gel. the size of nanoparticles were observed with sem.all prepared compounds w...
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