Browsing by Author "Vaishali"

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    A Catalyst- and Metal-free Approach towards the Synthesis of ?-Carboline tethered Imidazole Derivatives and Assessment of their Photophysical Properties
    (John Wiley and Sons Inc, 2023-04-25T00:00:00) Vaishali; Singh, Virender
    A simple, facile, and highly efficient approach has been unfolded for the syntheses of ?-carboline tethered imidazole derivatives. This expeditious catalyst-free strategy proceeds through the assembly of 1-formyl-9H-?-carbolines, glyoxal derivatives and ammonium acetate via the formation of concomitant four C?N bonds in a one-pot operation. The current approach has various advantages, including multicomponent nature, simple reaction conditions, short reaction time, broad substrate scope, and high product yield. Importantly, the ?-carboline tethered imidazole derivatives displayed excellent photophysical properties with quantum yield up to 90%. � 2023 Wiley-VCH GmbH.
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    An efficient metal-free and catalyst-free C�S/C�O bond-formation strategy: synthesis of pyrazole-conjugated thioamides and amides
    (Beilstein-Institut Zur Forderung der Chemischen Wissenschaften, 2023-03-02T00:00:00) Sharma, Shubham; Singh, Dharmender; Kumar, Sunit; Vaishali; Jamra, Rahul; Banyal, Naveen; Deepika; Malakar, Chandi C.; Singh, Virender
    An operationally simple and metal-free approach is described for the synthesis of pyrazole-tethered thioamide and amide conjugates. The thioamides were generated by employing a three-component reaction of diverse pyrazole C-3/4/5 carbaldehydes, secondary amines, and elemental sulfur in a single synthetic operation. The advantages of this developed protocol refer to the broad substrate scope, metal-free and easy to perform reaction conditions. Moreover, the pyrazole C-3/5-linked amide conjugates were also synthesized via an oxidative amination of pyrazole carbaldehydes and 2-aminopyridines using hydrogen peroxide as an oxidant. � 2023 Sharma et al.
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    From 2011 to 2022: The development of pyrazole derivatives through the ?,?-unsaturated carbonyl compounds
    (HeteroCorporation, 2023-11-25T00:00:00) Sharma, Shubham; Singh, Virender; Vaishali; Kumar, Rakesh; Jamra, Rahul; Banyal, Naveen; Jyoti
    The synthesis of pyrazole derivative using ?,?-unsaturated carbonyl compounds has attracted increasing attention of the synthetic organic chemist community. Interestingly, the simplicity of the synthetic method, high reactivity, and ease of incorporating diversity into the desired prototype have contributed a lot toward the exploration of ?,?-unsaturated carbonyl compounds by various research groups. Due to the tremendous pharmacological significance of pyrazole derivatives, their synthesis has been one of the leading research frontiers in recent years. As prime examples, sildenafil, zometapin, Celebrex, and rimonabant have been successfully commercialized in the market to treat various life-challenging diseases. Considering the great profile of ?,?-unsaturated carbonyl compound in the synthesis of biologically active pyrazole derivatives, this review incorporates contemporary literature (2011�2022) on the synthesis of pyrazole and its derivatives using ?,?-unsaturated carbonyl compound as a starting precursor. � 2023 Wiley Periodicals LLC.
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    Iodine-Catalysed Synthesis of ?-Carboline Tethered ?-Amino Amidines Through Ugi-Type Multicomponent Reaction
    (John Wiley and Sons Inc, 2022-09-15T00:00:00) Singh, Manpreet; Vaishali; Jamra, Rahul; Deepika; Kumar, Sunit; Singh, Virender
    A simple and efficient iodine catalysed protocol has been unfolded for the synthesis of novel ?-carboline C1-linked ?-amino amidines via one-pot assembly of 1-formyl ?-carbolines (Kumujian C analogues), anilines and isocyanides. This domino strategy proceeds through the formation of three C?N bonds in a single operation. The advantageous features of the developed methodology include one-pot synthesis, operational simplicity, high atom economy, broad substrate scope, multicomponent character, easy purification procedure (no column chromatography) and applicability towards gram scale synthesis. The scope of strategy has been demonstrated with the construction of a library of 32 novel ?-carboline tethered ?-amino amidines having three points of diversity. � 2022 Wiley-VCH GmbH.