An efficient catalytic method for fulvene synthesis

The effects of the nature and amount of base, substrate structure, amount of added water and solvent on the condensation of carbonyl compounds with cyclopentadiene in the presence of secondary amines were investigated. Based on these studies, a new efficient and green synthesis of fulvenes was developed.     

An efficient method for the synthesis of lignans

An efficient approach for the synthesis of several types of lignans (dibenzylbutanediols, dibenzylbutanes, substituted tetrahydrofurans, aryldihydronaphthalenes, arylnaphthalenes, and aryltetralins) was developed. The regioselective oxidative coupling of ethyl ferulate was used as the key step.     

An efficient method for the synthesis of tricycloquinazoline

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, p. 2457, October, 1990.     

An efficient method for the synthesis of gem-difluoroolefins

A series of gem-difluoroolefin derivatives were synthesized in moderate to good yields by the reaction of α,α-difluoro-β-carbonyl benzothiazol-2-yl sulfones (DFBTs) with various carbon nucleophiles. Using dl-proline as organocatalyst, the reaction of DFBT with acetone gave a tertiary alcohol, which could be further converted to the corresponding difluoroolefin by LDA.     

An efficient method for the synthesis of nitropiperidones

A three step efficient strategy for the synthesis of substituted 5-nitropiperidones in high de, employing Michael addition of N-p-tolylsulfinyl beta-nitroamines to alpha,beta-unsaturated esters, hydrolysis of the sulfinyl group, and cyclization of the resulting free amines, has been developed. A very simple experimental procedure involving mild conditions and only one chromatographic purification are the main features of the process.     

An efficient method for the partial synthesis of mixed-chain phosphatidylethanolamines

A high-yielding procedure for the semisynthesis of mixed-chain phosphatidylethanolamines is described. The key finding is that the reacylation of an N-tBOC-lysophosphatidylethanolamine methyl ester with a carboxylic acid can be achieved in high yield with DCC and DMAP. Deprotection of the phosphate and amino functionalities with sodium iodide and trifluoroacetic acid, respectively, provides the title compounds. The versatility of this procedure is illustrated with the synthesis of several mixed-chain phosphatidylethanolamines.     

An efficient electrochemical method for the synthesis of methylene blue

An efficient and one-pot electrochemical method for the synthesis of methylene blue based on the Michael-type reaction of electrochemically generated quinone-diimine derived from oxidation of N,N-dimethyl-p-phenylenediamine in the presence of sodium sulfide as nucleophile in aqueous solution via EC-ECECC mechanism is reported.     

An efficient method for the synthesis of C-C connected phthalocyanine-porphyrin oligomers

An efficient one-step method for the synthesis of covalently linked phthalocyanine-porphyrin (Pc-Por) hetero-dyads and Pc-Por-Pc hetero-triads, connected directly through C-C bonds, is presented. The procedure utilizes a Pd-mediated Suzuki cross-coupling reaction of a Pc-boronate synthon and a halogenated porphyrin. The two chromophores are directly linked, without spacer, through the β-pyrrolic-, meso-, and para-position of the meso-phenyl group of the porphyrins. The electronic absorption spectrum of the Pc-Por-Pc triad shows red-shifted, split Q-bands reflecting energy transfer.     

An efficient organocatalytic method for tandem synthesis of functionalized 2-pyridones

Highly functionalized 2-pyridones are obtained via a tandem reaction between primary amines and acetylenic esters in the presence of N-methylimidazole as an organocatalyst.     

An efficient method for synthesis of organophosphorus compounds in aqueous media

A convenient and facile one-pot synthesis of stable phosphorus ylides and 1,4-diionic organophosphorus compounds is reported by the reaction of triphenylphosphine,dialkylacetylenedicarboxylates and N-H,C-H or S-H acids in the presence of polyethyleneglycol (PEG),β-cyclodextrin(β-CD),glycerine(Gly) or ethyleneglycol(EG) in water.This methodology is of interest due to the use of water as a solvent,thus minimizing the cost operational hazards,and environmental pollution.     

An efficient method for the solid-phase synthesis of fluorescently labelled peptides

Fluorescent labelling of peptides is necessary in a wide range of cell biological applications. In the last decade, the application of cell-penetrating molecules has been advanced by the use of peptides, which have proven efficient in aiding nonpermeant molecules to cross the cell membrane. Currently, the development of new cell-penetrating peptides based on the design and synthesis of labelled peptide libraries is becoming critically important. Here we report an improved method for the solid-phase labelling of peptides, mediated by the activation of 5(6)-carboxyfluorescein with PyAOP/ HOAt.     

An efficient method for the synthesis of 2-thiazoleacetic acid N-sulfonyl amidines

Chemistry of Heterocyclic Compounds - A three-step method was designed and developed on the basis of retrosynthetic analysis for the synthesis of hybrid molecules containing a thiazole ring and an...     

An efficient solventless method for the synthesis of N,N-dialkyl sulfonamide derivatives

Aza-Michael addition of sulfonamides to α,β-unsaturated esters efficiently proceeds in the presence of catalytic amount of sodium hydroxide (NaOH) and tetrabutylammonium bromide (TBAB) as a phase-transfer catalyst (PTC) under microwave irradiation to afford N,N-dialkyl sulfonamides as biologically interesting compounds in good to excellent yields and short reaction times.     

An efficient method for solution-phase parallel synthesis of 2-quinoxalinol salen Schiff-base ligands

A solution-phase parallel method for the synthesis of 2-quinoxalinol salen ligands was designed and optimized. The synthesis begins with commercially available 1,5-difluoro-2, 4-dinitrobenzene (DFDNB) and employs a sequence of five straightforward and high-yielding reaction steps. Simple laboratory techniques with low sensitivity to water or air for solution-phase parallel reactions were coupled with convenient workup and purification procedures to give high-purity and yield a small ligand library of 20 compounds. The final step, a Schiff-base condensation of an aldehyde with the diaminoquinoxaline results in a new category of ligands for metal coordination or of potential bioactivity, based on the skeleton 2,2'-(1E,1'E)-(quinoxaline-6,7-diylbis(azan-1-yl-1-ylidene))bis(methan-1-yl-1-ylidene)diphenol. The approach described here is easily adaptable for parallel synthesis of a larger library.     

An efficient ultrasound-promoted method for the synthesis of bis(indole) derivatives

In this paper, the reaction of indole with electron-deficient alkenes in aqueous media is reported. This procedure allows the synthesis of bis(indole) derivatives in good to high yields at 90 °C under silent and ultrasound irradiation conditions. Short reaction times and high yields of desired products are the main advantages of the presented procedure. This reaction catalyzed by 12-tungstophosphoric acid is operationally simple and considers environmental aspects by avoiding toxic catalysts and solvents.     

An enzyme-encapsulated microreactor for efficient theanine synthesis

A flow-type microreactor containing glutaminase-mesoporous silica composites with 10.6 nm pore diameter (TMPS10.6) was developed for the continuous synthesis of theanine, a unique amino acid. High enzymatic activity was exhibited by the local control of the reaction temperature.     

An efficient synthesis of benzofuran derivatives under conventional/non-conventional method

<正>l-Methyl-3-ethyl imidazolium bromide[meim]Br/basic alumina(Al_2O_3) has been found to promote the cyclocondensation of chloroacetone/chloroethyl acetate with salicylaldehydes under conventional as well as microwave irradiation to yield benzofuran derivatives.     

An efficient synthesis of sulfamides

Here we report an efficient synthesis of sulfamides. 3,5-Lutidine was found to be an optimal solvent and catalyst for the reaction. The method was developed during our efforts to synthesize a series of novel FKBP-12 inhibitors in which the known ketoamide linker was replaced with sulfamide.     

An efficient synthesis of Ecopladib

An efficient synthesis of Ecopladib, an indole inhibitor of cytosolic phospholipase A₂α, is described. A new reaction involving indole C3 reductive alkylation using an acetal in the absence of water and a novel transformation of the C2 methyl to an aldehyde via dimethyl sulfoxide-mediated oxygen-transfer reaction are used in the present synthesis, which dramatically increased the synthetic efficiency.