Organic Chemistry Research
Volume:3 Issue: 1, Winter 2017

In this article, we describe a photosensitizer (PS) whose ability to generate singlet oxygen (1O2) and fluorescence emission has been designed as tumor responsive. More specifically, the PS consists of a silicon phthalocyanine (SiPc) core, axially substituted with two subphthalocyanine (SubPc) units, covalently linked by a disulfide linker, which is cleavable in the presence of a strong reducing agent. Initially, the SubPc units quench the SiPc fluorescent and 1O2-generating properties, most probably by electronic energy transfer. Upon entering a reducing environment, e.g., like those in tumor cells, the disulfide linker would be cleaved and the quenching would be undone, resulting in a sudden generation of 1O2 and a strong fluorescence of both the SiPc and SubPc units. Herein, this behavior has been probed in solution by means of using DTT as the reducing agent that induces the PS activation.

MgO nanopartticels (NP-MgO) in average size between 30—130 nm were prepared by sonochemistry method. Some phenols have been converted to ortho-hydroxybezaldehyd by ortho-formylation using MgO nanoparticles and (CH2O)n in xylene and subsequently treated with aqueous NH2OH.HCl, affording the corresponding aldoxime in a one-pot procedure. Moreover, this one-pot process, with two transformations, offers a number of advantages. In particular, the direct transformation of intermediates to the desired products reduces the time normally spent on isolation and purification.

Silica-bonded N-propyldiethylenetriamine (7) is employed as a recyclable heterogeneous solid base catalyst for the synthesis of 2-amino-3,5-dicarbonitrile-6-thiopyridines through pseudo four-component condensation reaction between aromatic aldehydes, malononitrile, and 2-amino-thiophenol in refluxing ethanol. Silica-bonded N-propyldiethylenetriamine showed much the same efficiency when used in consecutive reaction runs.

The use of a recyclable phase transfer catalyst, SiO2-PEG-ImBr, is demonstrated in a simple and highly efficient synthesis of phenacyl derivatives by nucleophilic substitution reaction of phenacyl halides with different anions in water. Advantages of this system are easy work-up, moderate to good yields, and recyclable catalyst. The catalyst can be recycled and reused several times with no loss of its efficiency.

T3P/DMSO is shown to be an effective and mild reagent for the one-pot synthesis of furo[2,3-d]pyrimidine-2,4(1H,3H)-diones from a variety of alcohols. Alcohols are oxidized in situ to aldehydes under mild conditions, which undergo a three-component reaction with N,N'-dimethylbarbituric acid and various isocyanides to afford furo[2,3-d]pyrimidine-2,4(1H,3H)-diones in good yields.

Due to the importance and various applications of nitriles especially in medicinal productions, a new method for conversion of aldehydes to nitriles has been presented. Several nitrile-containing aromatic compounds were synthesized through the treatment of various aldehydes and hydroxylamine hydrochloride as nucleophile in the presence of ferric hydrogen sulfate as a heterogeneous, efficient, and recyclable catalyst in DMF in good to excellent yields.

Fe3O4 nanoparticles were employment as an efficient and magnetically separable Nano catalyst for the synthesis of amides via one-pot Beckmann rearrangement of ketones under solvent-free conditions. Various secondary amides were synthesized by this method in moderate to good yields. The catalyst showed high thermal stability and was recovered and reused at least five times without any considerable loss of activity. The present process is environmentally benign and economical

A novel basic ionic liquid based on imidazolium cation is designed, synthesized and successfully used as a catalyst for the one-pot synthesis of 4-Oxo-6-aryl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile derivatives. The remarkable features of this new catalyst are its ethyleneoxy bridge which participates in dissolving organic compound in the ionic liquid and its strong base counterion. The application of this ionic liquid is studied in a new one-pot method for the synthesis of heterocyclic compounds under solvent-free conditions. A simple and convenient procedure, high conversion, reusability of catalyst, easy purification and shorter reaction time are the advantageous features of this method.

This study presents our view of unconventional and conventional intramolecular hydrogen bonds (HBs) for some beta-diketones theoretically and experimentally. According to our results, the groups such as Phenyl and t-But in beta positions increase and CF3 group decrease IHB strength, respectively. For better understanding of the substitution effects, the compounds with similar and different substitutions compared to each other experimentally and theoretically. Comparison between theoretical and experimental results, EHB and OH, show, by adding one substitution, these parameters change, which by adding another similar substitution, these changing approximately doubled. This conclusion achieved for DMPD, with phenyl and t-But groups in beta positions. Whereas, TFBA, with phenyl and CF3 groups, and TFDMHD, with CF3 and t-But groups in beta positions, don’t follow this achievement. The 1HNMR chemical shifts for the stable cis-enol forms of the mentioned compounds have been calculated at different levels with various basis sets in CHCl3 as solvent by using PCM method. For the most beta-diketones, the 6-311G** and 6-311++G** basis sets, in all our calculated levels, are in better agreement with the experimental results. According to AIM results, unconventional hydrogen bonding created in some beta-diketones, which have Ph group. The strength of this hydrogen bonding for these compounds are same and about 2 kcal/mol.

An efficient tandem synthesis of alkyl aryl ethers, including valuable building blocks of dialdehyde and dinitro groups under microwave irradiation and solvent free conditions on potassium carbonate as a mild solid base has been developed. A series of alkyl aryl ethers were obtained from alcohols in excellent yields by following the Williamson ether synthesis protocol under practical mild conditions. Scale up ability of this practical procedure is shown by the preparation of some of the valuable dialdehydes up to 50 mmole from alcohols. The method is simple, rapid, straight-forward and holds potential for further application in organic synthesis and industrial requirements.

Bicyclic aziridines show exclusive photochromic behavior. Here, we summarize the results of optical and electrochemical properties, such as photochemical, solvatochromic, electrochromic andkinetic behavior of bicyclic aziridines linked to chalcone moieties. The photochromic process for conversion of closed photoisomers to open photoisomers for compounds 1-10 followed zero-order kinetics. For considering the solvatochromic properties of compounds 1,3,5,7 and 9, photochromic properties of these compounds in different solvents were investigated and the negative solvatochromism were observed. The redox behavior of several derivatives of bicyclic aziridines by cyclic voltammetry was examined for compounds 1,3,5 and 6, and irreversible oxidation was observed.

Strecker reaction is one of the simplest multicomponent reactions. It used for synthesis of chiral α-amino nitriles. This reaction was carried out in the presence of catalytic amount of layered double hydroxides (LDHs). In this study, simple and practical method for the synthesis of this class of catalysts is provided. The results shown that LDH is the good heterogen catalyst for synthesis of chiral α-amino nitriles.