methanesulfonic acid (msa) was found to be an efficient catalyst for the synthesis of 1-substituted-1h-1,2,3,4-tetrazoles. a series of 1-substituted tetrazole compounds were synthesized from the reaction of various primary amines, sodium azide and triethyl orthoformate in the presence of catalytic amounts of msa at room temperature. in this protocol, some of the tetrazole derivatives were synth...

Phenylboronic acid esters are formed by the three common 2-deoxy aldoses: 2-deoxy-d-erythro-pentose ('2-deoxy-d-ribose'), 2-deoxy-d-lyxo-hexose ('2-deoxy-d-galactose'), and 2-deoxy-d-arabino-hexose ('2-deoxy-d-glucose'). The major species that was formed from equimolar quantities of boronic acid and the aldose, was the 3,4-monoester of the pentopyranose in a skew-boat conformation, and the 4,6-...

Recent progress in the development of phenylboronic acid (PBA)-functionalized layer-by-layer (LbL) assemblies and their biomedical applications was reviewed. Stimuli-sensitive LbL films and microcapsules that exhibit permeability changes or decompose in response to sugars and hydrogen peroxide (H2O2) have been developed using PBA-bearing polymers. The responses of PBA-modified LbL assemblies ar...

A water soluble, Bronsted acid, 5-sulfosalicylic acid as an efficient organocatalyst was used for the synthesis of physiologically active 2-substituted benzimidazole derivatives from o-phenylenediamine and aromatic aldehydes in ethanol at reflux condition. Cost-effectiveness, use of non-hazardous solvents, metal free and commercially available catalyst, single-step, environmentally fri...

Acetylated betulinic acid ( BA ) was converted into mono-substituted benzylamides 2 – 14 . Screening in SRB assays showed them as cytotoxic for a variety of different human tumor cell lines. While parent not within the limits assay (cut-off 30 ​μM), target amides were cytotoxic. Their bioactivity well their cell/non-tumor selectivity depended on substitution pattern aromatic ring. The most acti...

The surface of a gold (Au) disk electrode was modified with a self-assembled monolayer consisting of phenylboronic acid moiety to fabricate a voltammetric sensor sensitive to sugars. The modified Au electrode exhibited a voltammetric response to sugars in the presence of Fe(CN)6(3-) ion in the sample solution at neutral pH. The peak current of the cyclic voltammograms decreased depending on the...

In the current opinion, we would like to study adhesion of DNA and RNA−amphiphile complexes to non–modified glasses, glasses containing phenylboronic acid (PBA) attached via 3– glycidoxypropyltrimethoxysilane (GPTMS) [(PBA–GPTMS–glasses)] and glasses containing grafted dimethyllacrylamide–acrylamide phenylboronic acid (DMAA–AAPBA) copolymer (DMAA–AAPBA– glasses). We prepared glasses modified wi...

A number of 4-aryl- and 4-alkynyl-substituted 6H-1,2-oxazines 8 and 9 have been prepared in good yields via cross coupling reactions of halogenated precursors 2, which in turn are easily accessible by bromination of 6H-1,2-oxazines 1. Lewis-acid promoted reaction of 1,2-oxazine 9c with 1-hexyne provided alkynyl-substituted pyridine derivative 12 thus demonstrating the potential of this approach...

Non-substituted racemic poly(DL-lactic acid) (PLA) and substituted racemic poly(DL-lactic acid)s or poly(DL-2-hydroxyalkanoic acid)s with different side-chain lengths, i.e., poly(DL-2-hydroxybutanoic acid) (PBA), poly(DL-2-hydroxyhexanoic acid) (PHA), and poly(DL-2-hydroxydecanoic acid) (PDA) were synthesized by acid-catalyzed polycondensation of DL-lactic acid (LA), DL-2-hydroxybutanoic acid (...