POLY (ETHYLENE GLYCOL), A WATER-SOLUBLE POLYMER, IS ONE OF THE MOST WIDELY STUDIED STRUCTURAL COMPONENTS USED IN HYDROGEL NETWORKS DUE TO ITS HYDROPHILICITY AND BIOCOMPATIBILITY. PEG-BASED HYDROGELS WITH DESIRED PROPERTIES HAVE BEEN EXTENSIVELY EXPLORED IN TISSUE ENGINEERING AND OTHER BIOMEDICAL APPLICATIONS [1]. "click chemistry" [2] IS A STRONGLY GROWING APPROACH TO SYNTHESIZE THE WELL-DEFINED AND COMPLEX MACROMOLECULAR STRUCTURES BECAUSE OF ITS HIGH SPECIFICITY, QUANTITATIVE YIELDS, AND FUNCTIONAL GROUP TOLERANCE. RECENTLY, click chemistry HAS ATTRACTED A CONSIDERABLE AMOUNT OF ATTENTION FOR THE PREPARATION OF WELL-DEFINED HYDROGEL NETWORKS DUE TO THE CONTROLLED NETWORK FORMATION WHICH LEADS TO THE IMPROVED MECHANICAL PROPERTIES. IN THIS STUDY, WE HAVE EMPLOYED COPPER-CATALYZED HUISGEN’S 1, 3-DIPOLAR CYCLOADDITION OF AZIDES WITH ALKYNES AS THE COUPLING REACTION TO FORM FULLY HYDROPHILIC PEG HYDROGELS.

MOLECULAR RECEPTORS IN LIVING ORGANISMS PLAY BASIC ROLES IN THE NUTRITION, GROWTH AND DIFFERENTIATION OF LIVE CELLS [1]. ARTIFICIAL RECEPTORS ARE ABLE TO IMITATE THIS FUNCTION WHICH CAN HELP SCIENTISTS TO UNDERSTAND THE BEHAVIOR OF NATURAL PROCESSES AND ALSO CAN HELP US TO ARTIFICIAL DRUG DELIVERY COMPLEXATION AND CATALYSIS [2]. DIPHENYLGLYCOLURIL RECEPTORS HAVE BEEN PREPARED AND EXTENSIVELY STUDIED IN THE NOLTE RESEARCH GROUP [3].IN THIS WORK, WE WERE INTERESTED IN SYNTHESIZING SYSTEMS TO ACT AS AN ANION AND CATION RECEPTOR. COMPOUND (1) WAS PREPARED DURING FOUR STAGES FROM TWO SIMPLE STARTING MATERIALS, BENZALDEHYDE AND UREA. THIS COMPOUND WAS TREATED WITH SODIUM AZID TO OBTAIN TETRA-AZID ANALOGUE. IN THE LAST STEP, COMPOUND (2) WAS CONDENSED WITH PROPARGYL ALCOHOL BY A click REACTION TO FORM A FOUR-ARMED TETRAKIS-TRIAZOLYLDIPHENYLGLYCOLURIL. THIS SUPRAMOLECULAR CAN ACT AS AN ANION RECEPTOR BY HYDROGEN BONDING AND ALSO AS A CATION RECEPTOR BY NITROGEN NONBODING ELECTRON PAIRS.

IN 2001, SHARPLESS AND HIS CO-WORKERS SUCCESSFULLY OPTIMIZED THE REACTION OF AZIDE AND TERMINAL ALKYNE LEADING TO 1, 2, 3-TRIAZOLE VIA COPPER (I) CATALYSIS, SUBSEQUENTLY NAMED AS ONE OF ‘‘click’’ chemistry. THIS CONCEPT OF POPULAR REACTION HAS DRAWN WIDESPREAD ATTENTION DUE TO ITS HIGH EFFICIENCY, QUANTITATIVE YIELDS AND SELECTIVITY UNDER MILD REACTION CONDITIONS. THESE ADVANTAGES HAVE BEEN PARTICULARLY USEFUL IN THE AREA OF POLYMER chemistry. POLYMERS WITH DIFFERENT TOPOLOGIC STRUCTURES, INCLUDING LINEAR, BLOCK, STAR POLYMERS AND DENDRIMERS, HAVE BEEN REPORTED. THIS TECHNIQUE HAS ALSO BEEN WIDELY USED IN MATERIALS SCIENCE, SUCH AS BIOCONJUGATES AND VERSATILE FUNCTIONAL POLYMERS. IN VERY RECENT YEARS, click REACTIONS HAVE ALSO BEEN USED FOR THE SYNTHESIS OF LINEAR MAIN-CHAIN POLYTRIAZOLES BY THE STEP-GROWTH POLYMERIZATION. IN THIS INVESTIGATION, OUR AIM IS TO UTILIZE THE click REACTION TO SYNTHESIZE POLYMERS CONTAINING OXADIAZOL AND TRIAZOL RINGS IN THEIR BACKBONES FROM MONOMERS HAVING DIAZIDE AND DIALKYNE END GROUPS (SCHEME 1).

SYNTHESIS OF PEG BASED HYDROGEL FROM CONCURRENT COPPER (I)-CATALYZED AZIDE- ALKYNE CYCLOADDITION “click chemistry” WAS DEMONSTRATED. FIRSTLY, PEG AND PENAERYTHRITOL WERE FUNCTIONLIZED WITH AZIDE AND ALKYNE GROUPS RESPECTIVILY. WHEN THE SOLUTIONS OF THE TWO DERIVATIVES WERE MIXED TOGETHER, A CROSSLINKING REACTION, A TYPE OF HUISGENS 1, 3- DIPOLAR AZIDE- ALKYNE CYCLOADDITION IN THE PRESENCE OF CU (I) CATALYST OCCURS. THE PEG BASED HYDROGEL EXHIBIT HIGH SWELLING RATIOS AND GOOD MECHANICAL PROPERTIES. 2, 4-D WAS LOADED INTO THE HYDROGELS AND RELEASE OF THIS HERBICIDE IS BEING INVESTIGATED.

THE SYNTHESIS AND CHARACTERIZATION OF A NOVEL CLASS OF LINEAR AROMATIC ETHER POLYMERS CONTAINING TRIAZOLE AND OXADIAZOLE UNITES IS DESCRIBED. THESE POLYMERS WERE PREPARED FROM THE click chemistry OF NEW MONOMERS. THE STRUCTURES OF THE POLYMERS WERE CONFIRMED BY SPECTRAL TECHNIQUES.

1, 2, 3-TRIAZOLE DERIVATIVES ARE PHARMACOLOGICALLY VERY IMPORTANT CLASS OF COMPOUNDS AND HAVE RECEIVED CONSIDERABLE ATTENTION DUE TO THEIR ABILITY TO MIMIC PEPTIDE BONDS AND WORK AS PRECURSOR FOR A NUMBER OF IMPORTANT COMPOUNDS. IN 2001 SHARPLESS [1] AND MELDAL [2] INDEPENDENTLY DEVISED PROCESSES IN WHICH AZIDE AND ALKYNE HAVE PRODUCED TRIAZOLES IN THE PRESENCE OF COPPER CATALYST AS FASTER AND MORE REGIOSELECTIVE METHODOLOGY...

1, 3-BIS (4- [5, 5-DIMETHYLIMIDAZOLIDINE-2, 4-DIONE] -1H-1, 2, 3-TRIAZOL-4-YL) PROPAN-2-OL CAN OBTAINED BY TWO SUCCESSIVE STEPS. FIRSTLY 1, 3-DIAZIDO-2-PROPANOL (2) WAS OBTAINED IN 76% YIELD BY THE REACTION OF EPICHLOROHYDRIN...

THERE ARE VERY FEW 1, 2, 3-TRIAZOLE-CONTAINING MOLECULES ON THE MARKET OR ARE IN THE LAST STAGE OF CLINICAL TRIALS. POTENTIAL PHARMACEUTICALS BASED ON 1, 2, 3-TRIAZOLES INCLUDE THE ANTICANCER COMPOUND, B-LACTUM ANTIBIOTIC TAZOBACTUM, THE CEPHALOSPORINE CEFATRIZINE, AND SO ON [1]....