Synthesis of new derivatives of thieno[2,3‐b]pyridine fused with octyl ring

Derivatives of thiophene, thieno[2,3‐b]pyridine, thieno[5′,4′:4,5]pyrimido[3,2‐a]pyridine and thiepine fused with octyl ring have been synthesized and tested for antimicrobial and antifungal activities. The structure of the newly synthesized compounds have been established on the basis of their analytical and spectral data.     

Coordination‐Driven Self‐Assembly of PEO‐Functionalized Perylene Bisimides: Supramolecular Diversity from a Limited Set of Molecular Building Blocks

A limited number of poly(ethylene oxide)‐substituted perylene bisimides, some of which are equipped with terpyridine ligands for transition‐metal coordination (see structure), combine different types of noncovalent interactions to yield optoelectronically active organic materials with different types of supramolecular morphologies.

     

Simple microwave‐assisted ligand‐free suzuki cross‐coupling: Functionalization of halo‐pyrimidine moieties

An advantageous ligand‐free protocol for Suzuki couplings is described. The synthetic procedure entails microwave irradiation for the reduction of the reaction times and the use of silica cartridges for the purification. Dihalo‐pyrimidine structures, interesting scaffolds in medicinal chemistry, were chosen as test compounds.     

Synthesis of a novel class of 3‐(2′‐benzothiazolyl)‐2,3‐dihydroquinazolin‐4(1H)‐ones under solvent‐free and catalyst‐free conditions

A solvent‐ and catalyst‐free one‐pot three‐component condensation reaction approach was developed for the synthesis of a new class of 3‐(2′‐benzothiazolyl)‐2,3‐dihydroquinazolin‐4(1H)‐ones in relatively good yields.     

A Serum‐Resistant Low‐Generation Polyamidoamine with PEI 423 Outer Layer for Gene Delivery Vector

A new derivative of polyamidoamine and polyethylenimine, G2.5‐PEI 423 or G1.5‐PEI 423, is prepared by an amidation reaction of PAMAM G2.5 or PAMAM G1.5 using PEI 423. The polycations show a great ability to combine with pDNA to form complexes, which protect the pDNA from nuclease degradation. The polymers display stronger buffer capacity and lower cytotoxicity. The complexes have particle sizes of 120–180 nm and zeta potentials of 20–40 mV. The G2.5‐PEI 423 complexes display much higher transfection efficiencies than PAMAM G5 and Lipo‐2k, and the G1.5‐PEI 423 complexes display higher transfection efficiencies than PAMAM G4 and PEI‐25k. The complexes possess better serum‐resistant capacity. The G2.5‐PEI 423 has a great potential to be used as a serum‐resistant gene vector.

     

Solvent‐free synthesis of 5‐methyl‐7‐aryl‐4,7‐dihydrotetrazolo[1,5‐a]pyrimidine‐6‐carboxylic esters catalyzed by sulfamic acid

The solvent‐free synthesis of 5‐methyl‐7‐aryl‐4,7‐dihydrotetrazolo[1,5‐a]pyrimidine‐6‐carboxylic esters was performed and effectively catalyzed by sulfamic acid. Compared with conventional methods, this protocol features mild reaction conditions and high yields. Furthermore, it is solvent‐free and thus eco‐friendly.     

Synthesis of pyrazolo[3,4‐b]pyridines and attachment of amino acids and carbohydrate as linkers

Synthesis of novel pyrazolo[3,4‐b]pyridines has been achieved successfully by sequence of Gould ‐ Jacobs reaction between 5‐aminopyrazole and diethylethoxymethylenemalonate in good yield. Further the pyrazolo[3,4‐b]pyridines were converted into succinimidoyl active esters which are then replaced by biological samples such as amino acids and carbohydrate in slightly aqueous medium.     

Michael addition of dimedone with α,β‐unsaturated ketones: Synthesis of quinoline and chromene derivatives

A series of quinoline and chromene derivatives has been synthesized by Michael addition of dimedone 1 with 2‐aroyl‐3‐arylacrylonitrile 2 and study of absorption and fluorescence maxima of quinolines.     

Biosensing with Functionalized Single Asymmetric Polymer Nanochannels

In this work, we describe the direct covalent attachment of protein recognition elements (biotin) with the carboxyl groups present on the walls of polyimide nanochannels. Subsequently, these biotinylated channels were used for the bio‐specific sensing of protein analytes. Moreover, surface charge of these asymmetric nanochannels was reversed from negative to positive via the conversion of carboxyl groups into terminated amino groups. The negatively charge (carboxylated) and positively charged (aminated) channels were further used for the electrochemical sensing of bovine serum albumin (BSA, pI = 4.7). These biorecognition events were assessed from the changes in the ionic current flowing through the nanochannel.