A highly regio- and diastereo-selective synthesis of halogenated C-vinyl glycosides has been achieved from glycals and unactivated aryl acetylenes in the presence of halogenated Lewis acids via a tandem glycosylation-halogenation reaction. The Lewis acid used served the dual purpose of activating the allylic acetoxy group of glycals and serving as halogen source for Markovnikov addition across ...

The synthesis of 5-substituted 6,6a-dihydroisoindolo[2,1-a]quinolin-11(5H)-ones via [4 + 2] imino-Diels-Alder cyclization from N-aryl-3-hydroxyisoindolinones and N-vinyl lactams under Lewis acid-catalysed anhydrous conditions is reported. Reactions of N-(2-substituted-aryl)-3-hydroxyisoindolinones with N-vinylpyrrolidone under identical conditions resulted in the formation of 2-(2-substitued-ar...

1-Phenylthio-3-vinyl-cyclohex-1-en-3-ol (2) has been synthesized and investigated as a new bis-annelation reagent for silyl enol ethers. Reagent 2 can be synthesized by a Grignard reaction of vinyl magnesium bromide with 3-phenylthiocyclohexenone. The reaction with silyl enol ethers takes place under Lewis acid catalysis and generally proceeds in good yields. The resulting phenylthiodienes can ...

Arginine (Arg) is a commonly used additive to prevent protein aggregation and inactivation in denaturing solutions. This paper presents new findings on the synergistic effect on the prevention of heat-induced aggregation of lysozyme using Arg in combination with polyethylene glycol (PEG). The synergistic enhancement was observed in the presence of Arg with amphiphilic polymers, such as PEG6000,...

We report here the synthesis, electrochemical and photophysical properties of a series of novel exTTF-based organic dyes (3 and 7a,b) as well as their application in dye-sensitized solar cells (DSSCs). In the three designed dyes, the electron-donor exTTF group is connected to the rhodanine-3-acetic acid electron-acceptor unit through vinyl or vinyl-thiophene spacers. The electrochemical studies...

In this article, we synthesize a novel chitosan -based superabsorbent hydrogel via graft copolymerization of mixtures acrylic acid (AA) and N-vinyl pyrollidon onto chitosan backbones. The polymerization reaction was carried out in an aqueous medium and in the presence of ammonium persulfate (APS) as an initiator and N,N'-methylene bisacrylamide (MBA) as a crosslinker.The hydrogel structures wer...

THE increasing interest of biochemists in sulphydryl compounds has led to the necessity of finding some method for the accurate determination of these substances. That the problem is complex may be judged from the number of papers proposing new methods or modifications of old ones. The original procedure of Rosenheim and Davidsohn [1904] for the volumetric estimation of thiol acids by the use o...

This study aimed to synthesize quinolinone derivatives and investigate their cytotoxic activity. The compound 1-azacoumarin-3-carboxylic acid (2-oxo-1H-quinoline-3-carboxylic acid) was obtained via the cyclocondensation of 2-hydroxybenzaldehyde with diethyl malonate in base catalyst give ethyl coumarin-3-carboxylate, followed by ammonolysis ester (ethyl coumarin-3-carboxylate) ammonia presence ...

Structural changes of pyrene-labeled and unlabeled poly(maleic acid/octyl vinyl ether) (PMAOVE) and poly(maleic acid/methyl vinyl ether) (PMAMVE) with changes in pH have been investigated in this study. The changes in the photophysical properties of pyrene are interpreted to investigate uncoiling or swelling of the polymeric chains with pH. The vibrational fine structure of the pyrene fluoresce...