Letters in Organic Chemistry - Volume 17, Issue 9, 2020

The ortho effect arises in certain electrophilic aromatic substitutions when a meta director is meta to an ortho/para director. Among the three expected isomer products, only the two isomers ortho to the meta director are produced normally. To find an explanation for the ortho effect, nitrations of two properly substituted benzenes were explored. Evidence supported an explanation based on resonance involving the meta director.

Thiazolidine-2, 4-diones and their derivatives are a well-established chemical class of compounds that express their pharmacological actions through insulin sensitization and enhanced glucose utilization in peripheral tissues. In the current research different approaches have been employed to synthesize thiazolidine-2, 4-dione derivatives and these synthesized compounds were chemically characterized for the esta Read More

Phytochemical investigation of the methanolic extract of the stem bark of Casimiroa edulis afforded four coumarins. Various spectroscopic experiments were used to characterize the isolated coumarins. The structures were identified as auraptene (K-1), suberosin (K-2), 5-geranyloxypsoralen (bergamottin) (K-3), and 8-geranyloxypsoralen (K-4), based on the chemical and spectral analysis. Among these co Read More

In this study, a new type of luminogen with aggregation-induced-emission (AIE) behavior was designed and synthesized. The result of single-crystal X-ray structure showed a planar structure in which the dihedral angle between two aromatic rings is less than 30o. Moreover, two different intermolecular hydrogen bond interactions supported the stability of the crystal structure. After the formation of organic nanoparticles i Read More

We have successfully explored the potential MoO3 nanoparticles as a heterogeneous catalyst for the cyclocondensation of hydrazines/hydrazides with 1,3-dicarbonyl compound in aqueousalcoholic medium at room temperature. The present method has been developed using green chemistry measures and offers a range of N-substituted pyrazoles with moderate to excellent yields. Utilization of non-toxic catalyst, wide substrat Read More

A one-pot Cu-catalyzed synthesis of functionalized alkynyl imidamide by terminal alkynes, trichloroacetonitrile and aniline or benzyl amine is reported. The compounds were produced via coupling reaction of terminal alkynes with trichloroacetamidine. This method was performed under mild, ligand-free conditions and easy work-up method.

With regard to the importance of quinazoline as a privileged scaffold, herein we report the synthesis of twenty seven 2,4-disubstitute quinazoline derivatives in a new catalyst free condition. In the current work, poly ethylene glycol (PEG1000) as an inexpensive, very simple commercially available, ecofriendly and low melting point solvent was used. Air bubbling, a green oxidant, for oxidation purpose was also used. This is Read More

L-Proline was covalently tethered on thermoresponsive ionic block copolymers that formed micelles in aqueous solutions. The block copolymers consisted of a poly(N-isopropylacrylamide) (PNIPAAm) segment and an anionic or cationic polymer segment. These copolymers exhibited lower critical solution temperature (LCST) behavior at ca. 35-40°C, and achieved thermal stimuli-induced formation and dissociation of micelle Read More

This manuscript focuses on the reactions of 4-phosphorylated 5-hydroxyhexa-2,3-dienoates with protected or unprotected hydroxy groups involving 5-endo-trig cyclizations. Reactions with electrophiles result in mixtures of the 2,5-dihydro-1,2-oxaphosphole-5-carboxylates and the 5-phosphorylfuran- 2(5H)-ones by competitive electrophilic cyclization due to the neighboring phosphonate (phosphine oxide) and the carb Read More