Browsing by Author "Singh, Manpreet"

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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.
KI-assisted Sulfur Activation/Insertion/Denitration Strategy towards Dual C?S Bond Formation for One-pot Synthesis of ?-Carboline-tethered 2-Acylbenzothiophenes
(John Wiley and Sons Inc, 2021-12-13T00:00:00) Singh, Manpreet; Jamra., Rahul; Paul, Avijit K.; Malakar, Chandi C.; Singh, Virender
A simple and efficient KI promoted sulfur activation-insertion/de-nitration strategy has been developed for the synthesis of ?-carboline C1 tethered 2-acylbenzothiophenes via one-pot assembly of 1-acetyl ?-carbolines (an alkaloid based scaffold), 2-nirobenzaldehydes and elemental sulfur. This expeditious reaction proceeds through the formation of ?-carboline linked nitro-chalcones followed by embodiment of elemental sulfur to generate the multifunctional ?-carboline linked benzothiophene derivatives. The highlighted features of this efficient methodology are transition metal-free conditions, use of inexpensive and non-toxic catalyst, easy procedure, short reaction time, and broad substrate scope with good yields. The scope of this protocol has been extended for the synthesis of a range of novel compounds with significant diversity. � 2021 Wiley-VCH GmbH
Organic semiconducting materials for clean energy
(Elsevier, 2023-04-06T00:00:00) Singh, Manpreet; Husain, Ahmad; Kaur, Kamalpreet
The goal of the present chapter is the maximum utilization of organic semiconducting materials such as organic solar cells. Organic solar cells have built a step forward and incredible development in overcoming the long-standing challenges of low power conversion efficiencies (PCEs) and device lifetimes. The most concerning OSC property has been PCE, collectively with device durability and lifetime, key for large-scale usage. Recent advances in OSCs have exhibited 16.5% PCE in single-junction devices and 17.3% in tandem devices. At present, the device structure of OSCs is mainly classified into three types: bilayer, single-layer Schottky junction, and bulk heterojunction (BHJ) OSCs. The basic structure of these three devices is the same. It incorporates four components from the bottom to the top: the anode electrode material and the organic active layer material, the cathode electrode material, and glass substrate. The organic active layer material is situated between the cathode and anode to form a device with a unique �sandwich� structure. The main difference between the three structured devices is the morphology of the active layer. Due to the structure of BHJ, the interface contact area to the donor/acceptor materials in the active layer is increased dramatically. Meanwhile, a good cross-network structure can be found in the blend films, which is favorable to the carrier transport in the active layer films. Therefore BHJ has grown to be a usually used structure for OSCs. BHJ will allow organic solar cells to be economically competitive with conventional inorganic solar cells and possibly replace them in the future. This chapter describes the incredible progress in the past few years in OSCs toward high PCE, large-area, and long-lasting operation, displaying a bright future for large-scale applications for high-efficiency solar cells. � 2023 Elsevier Ltd. All rights reserved.
Potassium Tert-Butoxide-Promoted Synthesis of Fluorescent ?-Carboline Tethered 1,3,5-Triazines and Assessment of Their Luminescent Properties
(John Wiley and Sons Inc, 2021-07-05T00:00:00) Singh, Manpreet; Jamra, Rahul; Mehra, Saloni; Rattan, Sunita; Singh, Virender
A transition metal-free, base-mediated efficient synthesis of novel ?-carboline C1(3) tethered triazines has been accomplished by using ?-carboline alkaloid; Kumujian C as a template for reaction with readily available amidines. The strategy has been found compatible with diverse 1(3)-formyl ?-carbolines and amidines, providing access to wide variety of novel ?-carboline linked 1,3,5-triazines in good to excellent yields. The methodology is also amenable to gram scale synthesis of triazines. The presented methodology features sustainable reaction conditions, clean and simple methodology, low environmental impact, wide substrate scope and high atom economy with good to excellent yields. Moreover, the light emitting properties of these fluorescent ?-carboline linked triazine derivatives were investigated for the first time where quantum yield (?F) up to 60% was obtained. � 2021 Wiley-VCH GmbH
Transition-Metal-Free Cascade C-N Bond Formation: An Effective Strategy for the Synthesis of ?-Carboline N-Fused Imidazolium Acetates and Estimation of their Light-Emitting Properties
(Georg Thieme Verlag, 2023-08-08T00:00:00) Singh, Manpreet; Vaishali, Vaishali; Deepika, Deepika; Jyoti, Jyoti; Sharma, Shubham; Banyal, Naveen; Kumar, Prashant; Budhalakoti, Bharti; Malakar, Chandi C.; Singh, Virender
A simple, efficient, and practical metal-free protocol has been devised to synthesize imidazopyrido[3,4-b]indole-based fluorophores decorated with carbazole/ F-carboline/pyridine scaffolds via three consecutive C.N bond formations in a single operation. A wide range of aromatic amines (2-aminopyridines, 3-aminocarbazole, and anilines) were successfully applied to synthesize the complex imidazolium ions. The significant features of this strategy include high efficiency, mild and environmentally benign reaction conditions, no chromatographic purification, and broad substrate scope with excellent yields of the isolated products. Moreover, excellent photophysical properties (up to 85%) were exhibited by these fluorophores. � 2022 Georg Thieme Verlag. All rights reserved.