1,3-Dipolar cycloaddition of C-(2-thiazolyl)nitrones to chiral acrylates. Synthesis of enantiopure α-amino-2-alkylthiazoles and 5-formylpyrrolidin-2-ones

Synthesis and Studies of Potential Antifungal and Antibacterial Agents New Aryl Thiazolyl Mercury (II) Derivatives Compounds

Combination of mercaptothiazoles and mercury phenyl chloride synthesized some new compounds of thiazoles. Firstly some mercaptothiazoles with different sorts have been synthesized, and then synthesized compounds were reacted with different mercury phenyl chloride structures. At last, each of these synthesized compounds was purified. Consequently, these structures were recrystallized using oil ether. Forming product through chromatogram (TLC) and combination ofRfwith other compound'sRfof were identified, and their purity percent was recognized. The1H-NMR and other methods like FT-IR and mass spectroscopy have determined all of compounds. Obtained results of synthesized compounds showed that reactions were carried out with suitable speed and high yield.

Nitrones in synthetic polymer chemistry

Very recently, the development of enhanced spin capturing polymerization (ESCP) and nitrone-mediated radical coupling (NMRC) reactions—based on nitrone chemistry—has opened up novel synthetic avenues in macromolecular engineering. The synthetic potential of nitrones in polymer chemistry is discussed herein.

Asymmetric 1,3-dipolar cycloadditions of acrylamides

This critical review, which is relevant to researchers in synthetic organic chemistry, focuses on asymmetric 1,3-dipolar cycloadditions with acrylamides. The use of chiral acrylamides as dipolarophiles leads to high levels of stereocontrol, due to conformational constraint in the acrylamides. Employment of chiral tertiary acrylamides containing nitrogen heterocycles is particularly effective in controlling the stereoselectivity. Following a general overview of 1,3-dipolar cycloadditions, the main body of the review focuses on asymmetric 1,3-dipolar cycloadditions of acrylamides with nitrile oxides, nitrones, diazoalkanes and azomethine ylides, with particular emphasis on the rationale for the observed stereocontrol (215 references).

Conformational Preferences of Methacrolein in Diels−Alder and 1,3-Dipolar Cycloaddition Reactions

A B3LYP/6-31G* study has been carried out for the reactions of methacrolein with cyclopentadiene, parent nitrone, 1-pyrroline-1-oxide, and (Z)-C,N-diphenylnitrone, in which the coordination of a Lewis acid (borane) and the solvent polarity (dichloromethane) have been taken into account. Calculated activation parameters, regioselectivities (for 1,3-dipolar cycloaddition reactions), and endo/exo stereoselectivities show good agreement with available experimental data. Gas-phase calculations show a varied behavior of the s-cis/s-trans TS stability for noncatalyzed reactions (from the systematic s-cis preference for the cyclopentadiene reaction to the systematic s-trans predilection encountered in the diphenylnitrone cycloaddition). BH3 coordination leads to a preferential stabilization of s-trans TSs in the reactions of cyclopentadiene (exo approach) and diphenylnitrone but a larger stabilization of s-cis structures in the processes involving the parent nitrone or 1-pyrroline-1-oxide. Additionally, a rather systematic preferential stabilization of s-trans structures is induced by solvent polarity in most reactions. As a consequence, an s-trans preference is predicted in solution for both thermal and catalyzed types of reactions in most approaches. Such a conclusion is consistent with some experimental results suggesting a preference for a particular conformation of the methacrolein-Lewis acid complexes.