Jahangir Ahmad war

Bio: Jahangir Ahmad war is an academic researcher. The author has contributed to research in topics: X-ray photoelectron spectroscopy & Materials science. The author has an hindex of 1, co-authored 1 publications receiving 3 citations.

α-Aminoazoles/azines: key reaction partners for multicomponent reactions

Abstract: Aromatic α-aminoazaheterocycles are the focus of significant investigations and exploration by researchers owing to their key role in diverse biological and physiological processes. The existence of their derivatives in numerous drugs and alkaloids is due to their heterocyclic nitrogenous nature. Therefore, the synthesis of a structurally diverse range of their derivatives through simple and convenient methods represents a vital field of synthetic organic chemistry. Multicomponent reactions (MCRs) provide a platform to introduce desirable structure diversity and complexity into a molecule in a single operation with a significant reduction in the use of harmful organic waste, and hence have attracted particular attention as an excellent tool to access these derivatives. This review covers the advances made from 2010 to the beginning of 2020 in terms of the utilization of α-aminoazaheterocycles as synthetic precursors in MCRs.

Chiral Phosphoric Acid–Catalyzed Enantioselective Formal [4+2] Cycloaddition between Dienecarbamates and 2–Benzothioazolimines

Abstract: An enantioselective chiral phosphoric acid catalyzed formal [4+2] cycloaddition between 2-benzothiazolimines and N-H-1,3-dienecarbamates is described. A divergence in reaction pathways was observed depending on the dienes employed. The reaction performed with 4-substituted dienes produced benzothiazolopyrimidines as major product in yields ranging from 42 to 67%, as single diastereoisomer and with enantioselectivity between 93 and 99%. The same reaction performed with 3-substituted dienes, however, gave highly enantioenriched 1,2,3,4-tetrahydroquinolines as the major products albeit with moderate diastereoselectivity.

Kaolin-catalysed one-pot synthesis of thiophene containing aminonaphthols under solvent-free condition and their in vitro anticancer and antioxidant activity

Abstract: An efficient and eco-friendly synthetic protocol via a one-pot three-component reaction to yield thiophene containing aminonaphthols (Betti bases) is reported. Kaolin was used as a heterogeneous catalyst and a series of Betti bases were synthesized under solvent-free condition. The synthesized derivatives were characterized by various techniques, viz. FTIR, 1H-NMR, 13C-NMR, mass spectrometry and elemental analysis. The synthesized compounds were screened for in vitro anticancer and antioxidant activities. Compounds 4d, 4i, 4j exhibited excellent anticancer activity (GI50 < 10 µg/ml) against all four cell lines which was comparable with the standard drug doxorubicin. Compound 4d was found to be the most potent antioxidant against DPPH radical and H2O2. The reusability studies demonstrated the retention in catalytic activity for up to six cycles. The current synthetic methodology offers several advantages such as excellent yields, mild reaction conditions, short reaction span, ease of work-up, broad substrate scope and reusability.