An efficient two-step synthesis of 3-allylindoles

A two-step synthetic sequence for an efficient synthesis of 3-allylindoles is described.     

Colorimetric Enzyme Sensing Assays via In Situ Synthesis of Gold Nanoparticles

We report a successful facile and novel approach for in situ synthesis of gold nanoparticles (AuNPs) via enzymatic dephosphorylation reaction at room temperature. Fmoc-tyrosine phosphate and cytidine-5-mono phosphate are used to sense the activities of an enzyme alkaline phosphatase. Formation of AuNps is highly selective towards biomolecules and it is readily detected colorimetrically and UV–Vis analysis. In this procedure, dephosphorylated product plays both roles as reducing and stabilizing agent to direct the formation of AuNPs in aqueous media. Transmission electron microscopic study reveales that hexagonal AuNPs were synthesized by using Fmoc-tyrosine phosphate and alkaline phosphatase. Wide angle X-ray scattering data confirms the formation of AuNPs. FT-IR studies confirm that biomolecules play crucial role to stabilize the AuNPs by molecular interactions with the surface of AuNPs. In situ synthesized AuNPs are applied for the sensing of enzyme activity.     

Simple and Efficient Synthesis of 2-Aryl-2,3-Dihydroquinolin-4(1H)-ones Using Silica Chloride as a New Catalyst Under Solvent-Free Conditions

A mild, efficient, and high-yielding method for the synthesis of 2-aryl-2,3-dihydroquinolin-4(1H)-ones from their corresponding 2-amino chalcones using silica chloride (SiO₂Cl) under solvent-free conditions is described. A series of 2-aryl-2,3-dihydroquinolin-4(1H)-ones containing both electron-donating and electron-withdrawing substituents were synthesized.     

Efficient copper-catalyzed Sonogashira coupling reactions and simulation studies

A practical copper-catalyzed I-substitutions of alkyl-2-iodobenzoates with alkynes have been developed using Cu powder as a catalyst under solvent, cocatalyst, and base-free conditions. This reaction system is new, facile, efficient, and economical that gives Sonogashira coupling products in excellent yields (up to 97%). The coupled products (A–J) were characterized by CHNS, ¹H NMR, and ¹³C NMR and are found soluble in ethyl acetate and dichloromethane. In addition, simulation studies of A–J were performed with aspulvinone dimethylallyltransferase enzyme and observe good binding affinity. The reported compounds may act as anti-cizmatics, anti-fobic in future and also have the inhibition of aspulvinone dimethylallyltransferase properties to control Alzheimer’s, Schizophrenia, etc. diseases.     

A short and efficient synthesis of furo[2,3-b]indoles

Application of Wittig olefination-Claisen rearrangement protocol for the short synthesis of furo[2,3-b]indoles is described.     

BODIPY based colorimetric fluorescent probe for selective thiophenol detection: theoretical and experimental studies

A BODIPY-based selective thiophenol probe capable of discriminating aliphatic thiols is reported. The fluorescence off-on effect upon reaction with thiol is elucidated with theoretical calculations. The sensing of thiophenol is associated with a color change from red to yellow and 63-fold enhancement in green fluorescence. Application of the probe for selective thiophenol detection is demonstrated by live cell imaging.     

A chromenoquinoline-based fluorescent off-on thiol probe for bioimaging

A new chromenoquinoline-based fluorescent off-on thiol probe 2 is reported. In aqueous buffer solutions at physiological pH, the probe exhibited 223-fold enhancement in fluorescence intensity by a Michael addition of cysteine to the maleimide appended to a chromenoquinoline. Cell permeability and live cell imaging of thiols are also demonstrated.     

Original diols from sunflower and ricin oils: Synthesis,characterization, and use as polyurethane building blocks

A series of novel fatty acid‐based diols were designed and synthesized from sunflower and ricin oils using optimized chemical reactions and purifications. These diols were categorized in two different types: (i) fatty acid‐based monoester containing diols (FAmE‐1 to FAmE‐6) and (ii) fatty acid‐based diester containing diols (FAdE‐1 to FAdE‐8). Their synthesis involved a series of reactions such as transesterification, epoxidation, ring opening of epoxide, and thiol‐ene additions. Analyses of these new fatty acid‐based diols were performed by HPLC/GC and NMR spectroscopy. The latter were then demonstrated as polyurethane (PU) precursors in the bulk polymerization with isophorone diisocyanate in the presence of dibutyl tin dilaurate as a catalyst. The effects of the diol nature and purity on the PU synthesis and properties were investigated. The structural characterization of the different PUs was carried out by means of FTIR, ¹H NMR, and ¹H DOSY NMR spectroscopy. The thermomechanical and rheological properties of these new PUs were found dependent on the chemical structure and purity of the diol building block. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

A Palladium‐Catalyzed Carbonylation Approach to Eight‐Membered Lactam Derivatives with Antitumor Activity

The reactivity of 2‐(2‐alkynylphenoxy)anilines under PdI₂/KI‐catalyzed oxidative carbonylation conditions has been studied. Although a different reaction pathway could have been operating, N‐palladation followed by CO insertion was the favored pathway with all substrates tested, including those containing an internal or terminal triple bond. This led to the formation of a carbamoylpalladium species, the fate of which, as predicted by theoretical calculations, strongly depended on the nature of the substituent on the triple bond. In particular, 8‐endo‐dig cyclization preferentially occurred when the triple bond was terminal, leading to the formation of carbonylated ζ‐lactam derivatives, the structures of which have been confirmed by XRD analysis. These novel medium‐sized heterocyclic compounds showed antitumor activity against both estrogen receptor‐positive (MCF‐7) and triple negative (MDA‐MB‐231) breast cancer cell lines. In particular, ζ‐lactam 3 j′ may represent a novel and promising antitumor agent because biological tests clearly demonstrate that this compound significantly reduces cell viability and motility in both MCF‐7 and MDA‐MB‐231 breast cancer cell lines, without affecting normal breast epithelial cell viability.     

Single-step purification and immobilization of penicillin acylase using hydrophobic ligands

Five differenthydrophobic ligands immobilized on 4% (4XL) and 6% (6XL) crosslinked agarose were used to study the single-step purification of penicillin acylase from cell lysate. The 4XL gels showed relatively higher specific activity and recovery than the 6XL gels. In single-step purification, highly active enzyme (42 U/mg) was obtained using moderately hydrophobic ligand (octyl). The crude enzyme immobilized on octyl gel by adsorption showed significant operational stability over a period of 30 d at room temperature. Reactor studies demonstrated the feasibility of hydrophobic ligands as a medium for immobilization.