Journal of Combinatorial Chemistry

In this work, a novel one-pot multicomponent reaction of 2-aminophenols, Meldrum's acid, and isocyanides leads to the synthesis of tetrahydrobenzo[b][1,4]oxazepine or malonamide derivatives using 1 or 2 equiv of 2-aminophenols, respectively, in good to excellent yields at ambient temperature.

No abstract text is available yet for this article.

Diverse 2H-isoindol-1-ylphosphonates as potential HCT-116 inhibitors are easily generated via a FeCl(3) and PdCl(2) cocatalyzed three-component reaction of 2-alkynylbenzaldehyde, aniline, and phosphite. The focused small library is constructed based on parallel diversity-oriented synthesis.

In a one-pot procedure, bromine less brominating reagent 1,1'-(ethane-1,2-diyl)dipyridinium bistribromide (EDPBT) has been utilized as an efficient desulfurizing agent for the construction of a library of heterocycles containing N, O, and S starting from aryl/alkyl isothiocyanates. In this approach, aryl/alkyl isothiocyanate reacts with o-phenylenediamine (o-PD), o-aminophenol, and o-aminothiophenol to form their monothiourea which on desulfurization with EDPBT led to the formation of corresponding 2-aminobenzimidazoles, 2-aminobenzoxazoles, and 2-aminobenzothiazoles, respectively...

The Pipecolic linker is a new highly versatile handle which immobilizes on solid support through a carboxylic acid function a wide range of amines, alcohols, and hydrazines. The anchoring step on pipecolic resin is very easy and efficient, and compounds are released with high purities upon acidic treatment. During this treatment, an oxazolonium intermediate is hydrolyzed, yielding the cleavage of ester or amide bond and the release of free carboxylic acid of the starting linker. In this study, we report the possibility of recycling the pipecolic resin after the use of several trifluoroacetic acid (TFA) cleavage cocktails...

A simple and efficient protocol for one-pot three-component coupling of isatoic anhydride, amines, and aldehydes in water using magnetically recoverable Fe(3)O(4) nanoparticles is reported. This methodology results in the synthesis of a variety of 2,3-dihydroquinazolin-4(1H)-ones in high yields. The catalyst can be recovered and recycled without a significant loss in the catalytic activity.

Highly efficient palladium-catalyzed reaction of 1-(2,2-dibromovinyl)-2-alkenylbenzene with arylboronic acid is disclosed, which generates the functionalized 1-methylene-1H-indenes in good yields. Tandem Suzuki-Miyaura coupling and Heck reactions are involved in this process.

On-bead screening of one-bead one compound (OBOC) libraries is an ultra fast surface based primary high-throughput screening (HTS) method. Typically the binding of a tagged target protein to bead immobilized compounds or its altered enzymatic activity are detected. For an efficient and reliable ligand discovery process secondary assays to confirm on-bead compound activity in homogeneous solution are key to exclude artifacts and weak binders. Ideally they should allow to flag hit compounds with undesirable biophysical properties such as aggregation, unspecific binding, or insufficient solubility and the like...

Intracellular levels of the hypoxia-inducible transcription factor (HIF) are regulated under normoxic conditions by prolyl hydroxylases (PHD1, 2, and 3). Treatment of cells with PHD inhibitors stabilizes HIF-1α, eliciting an artificial hypoxic response that includes the transcription of genes involved in erythropoiesis, angiogenesis, and glycolysis. The different in vivo roles of the three PHD isoforms are not yet known, making a PHD-selective inhibitor useful as a biological tool. Although several chemical series of PHD inhibitors have been described, significant isoform selectivity has not been reported...

No abstract text is available yet for this article.

A series of novel spiropyrrolidines and spirothiapyrrolizidines were synthesized via a three-component 1,3-dipolar cycloaddition reaction of isatin or acenaphthenequinone, sarcosine or thiaproline and 4-hydroxy-6-methyl-3-((E)-3-phenylacryloyl)-2H-pyran-2-ones in refluxing ethanol. Advantages of this method include the availability of starting materials, mild reaction conditions, high yields, and the complete regioselectivity observed.

An efficient method to synthesize positional scanning synthetic combinatorial libraries (PS-SCLs) for studying the specificity of protein kinases is presented. Isokinetic ratios for pentafluorophenyl esters were determined iteratively using a new approach incorporating high performance liquid chromatography (HPLC) quantification and statistical experimental design. In the development process a large amount of work was put in to find efficient ways of screening for new isokinetic mixtures and to optimize the process of PS-SCL synthesis...

A method to efficiently immobilize and partition large quantities of microbeads in an array format in microfabricated poly(dimethylsiloxane) (PDMS) cassette for ultrahigh-throughput in situ releasable solution-phase cell-based screening of one-bead-one-compound (OBOC) combinatorial libraries is described. Commercially available Jeffamine triamine T-403 (∼440 Da) was derivatized such that two of its amino groups were protected by Fmoc and the remaining amino group capped with succinic anhydride to generate a carboxyl group...

Indium trichloride is an efficient catalyst for the sequential four-component reaction between aliphatic amines, β-ketoesters, α,β-unsaturated aldehydes, and ethanol to afford 6-ethoxy-1,4,5,6-tetrahydropyridines, which were converted in situ into 5,6-unsubstituted 1,4-dihydropyridines via ethanol elimination in the presence of neutral Al(2)O(3), in a very efficient, one-pot protocol from acyclic, readily available starting materials that involves the generation of two C-N σ and one C-C π bonds. The structural variety of the dihydropyridine library thus generated was extended by base-promoted γ-alkylation of their C-2 position...

A simple and efficient approach to the synthesis of a novel series of polysubstituted 6'-(1H-indol-3-yl)-1',7'-dihydrospiro[indoline-3,4'-pyrazolo[3,4-b]pyridine]-2-one derivatives in high yields was developed from a one-pot, three-component reaction of 3-cyanoacetyl indoles, isatins, and 1H-pyrazol-5-amines in H(2)O/HOAc.

The one-pot synthesis of a new substituted 1,2,3,4-tetrahydrocarbazoles has been described via Petasis reactions. These tetrahydrocarbazoles exhibits various medicinal importance and might be suitable for elaboration into larger peptides at carboxy termini. The scope and limitations of this method have been examined.

Cathepsin V is a papain-like cysteine protease. It is involved in the control of human T cells (responsible for cell immunity), and presents the largest elastolytic activity among the proteolytic enzymes. Therefore, cathepsin V is a potential molecular target for the treatment of atherosclerosis. In the present work, natural flavonoids were screened against cathepsin V, and two flavones were identified as potent inhibitors of cathepsin V. On the basis of this result, a combinatorial library of chalcones and flavones was prepared, in solution phase employing a scavenger reagent, and fully evaluated...

Maskless photolithographic peptide synthesis was performed on a glass chip using an automated peptide array synthesizer system. The peptide array synthesizer was built in a closed box, which contained optical and fluidic systems. The conditions for peptide synthesis were fully controlled by a computer program. For the peptide synthesis on a glass chip, 20 NVOC-protected amino acids were synthesized. The coupling efficiencies of two model peptide sequences were examined on ACA/APTS and PEG/CHI/GPTS chips. PEG/CHI/GPTS chip gave higher average stepwise yields of GIYWHHY (94%) and YIYGSFK (98%) than those of ACA/APTS chip...

Instead of developing a novel red phosphor individually, this work proposes the production of white light by combining a near-ultraviolet/ultraviolet diode chip with blue and special yellow phosphors: the yellow phosphor includes the red and green components with high color saturation. The availability of this scheme is demonstrated by preparing a white light-emitting diode (WLED) with color rendering index (Ra) up to 90.3. The desired single-mass yellow phosphor is successfully screened out from the YVO(4):Bi(3+),Eu(3+) system by using a combinatorial chemistry approach...

The design and synthesis of small molecules that target RNA is immensely important in antibacterial therapy. We had previously reported on the RNA binding of a series of 4,5-disubstituted 2-oxazolidinones that bind to a highly conserved bulge region of bacterial RNA. This biological target T box antitermination system, which is found mainly in Gram-positive bacteria, regulates the expression of several amino acid related genes. In an effort to amplify our library, we have prepared a library of 1,4-disubstituted 1,2,3-triazole analogs that entails an isosteric replacement of the oxazolidinone nucleus...