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Item Tandem transformation of indazolones to quinazolinones through pd-catalyzed carbene insertion into an n–n bond(ACS, 2023-01) Shakuja, RajeevSerendipitous and expedite transformation of 1-aryl- and 2-aryl-1,2-dihydro-3H-indazol-3-ones to 1,2-di(hetero)aryl- and 2,3-di(hetero)aryl-2,3-dihydroquinazolin-4(1H)-ones, respectively, was achieved in high efficiency by reacting them with aldehydic N-tosylhydrazones. The protocol proceeded through a cascade process involving base-mediated Pd-carbenoid generation by the decomposition of N-tosylhydrazones, nucleophilic attack of indazolone on the Pd-carbenoid complex, and intramolecular ring expansion via N–N bond cleavage. The utility of the strategy is demonstrated toward the synthesis of bioactive NPS 53574, a calcium receptor antagonist.Item RH(III)-catalyzed fabrication of [4,3,1]-bridged azaheterocycles using quinone monoacetals(ACS, 2025-06) Sakhuja, RajeevA rhodium-catalyzed annulation strategy for the fabrication of cyclohexanone-bridged indazolones and other related diazole-ones and diazine-ones was established using quionone monoacetals under mild conditions. On the other hand, the use of 4-hydroxy-4-methylcyclohexa-2,5-dienone under the optimized Rh-conditions produced an ortho-CAr-arylated product in moderate reactivity. Mechanistic studies suggested that the coupling proceeded via one-pot C–H activation-Michael/hetero-Michael additions into the enone moiety. Interestingly, the [4,3,1]-bridged-1,2-dihydro-3H-indazol-3-ones underwent unexpected migratory aromatization in acidic condition to produce 3-hydroxy-14H-benzo[c]indazolo[1,2-a]cinnolin-14-ones in high yields.Item Electrochemical Oxidative Coupling Between Benzylic C(sp3)–H and N–H of Secondary Amines: Rapid Synthesis of α-Amino α-Aryl Esters(ACS, 2021-06) Kumar, IndreshAn intermolecular electrochemical coupling between the benzylic C(sp3)–H bond and various secondary amines is reported. The electronic behavior of two electronically rich units viz the α-position of α-aryl acetates and amines was engineered electrochemically, thus facilitating their reactivity for the direct access of α-amino esters. A series of acyclic/cyclic secondary amines and α-aryl acetates were tested to furnish the corresponding α-amino esters with high yields (up to 92%) under mild conditions.Item Asymmetric Synthesis of Bridged N-Heterocycles with Tertiary Carbon Center through Barbas Dienamine-Catalysis: Scope and Applications(ACS, 2021-11) Kumar, Indresh; Kumar, DalipA direct aza-Diels–Alder reaction between 2-aryl-3H-indolin-3-ones and cyclic-enones has been developed to access chiral indolin-3-one fused polycyclic bridged compounds. This method proceeds via proline-catalyzed Barbas-dienamine intermediate formation from various cyclic-enones such as 2-cyclopenten-1-one, 2-cyclohexene-1-one, and 2-cycloheptene-1-one, followed by a reaction with 2-aryl-3H-indol-3-ones. Several indolin-3-ones fusing [2.2.2], [2.2.1], and [3.2.1] skeletons decorated with a tertiary carbon chiral center have been prepared. Computational studies (DFT) supported the observed stereoselectivity in the method. The synthesized compounds have shown exciting photophysical activities and selective sensing of Pd2+ and Fe3+ ions through the fluorescence quenching “switch-off” mode.Item Electrochemical Synthesis of 2-Aryl-3-(2-aminoaryl)quinoxalines via Oxidative Dearomatization/Ring-Opening/Cyclization Cascade Sequence of 2-Arylindoles with 1,2-Diaminoarenes(ACS, 2023-07) Kumar, IndreshA straightforward method has been developed to synthesize 2-aryl-3-(2-aminoaryl) quinoxalines from 2-arylindoles and 1,2-diaminoarenes under mild electrochemical conditions. The reaction proceeds through in situ generations of 2-arylindole-3-ones under electrochemical oxidative dearomatization of 2-arylindoles, followed by a ring opening-cyclization sequence with 1,2-diaminoarenes. A series of 2-aryl-3-(2-aminoaryl) quinoxalines have been prepared with moderate to good yields (up to 75%).Item Direct Amine-Catalyzed Enantioselective Synthesis of Pentacyclic Dibenzo[b,f][1,4]oxazepine/Thiazepine-Fused Isoquinuclidines along with DFT Calculations(ACS, 2020-10) Kumar, Dalip; Kumar, IndreshA direct protocol for the asymmetric synthesis of dibenzoxazepine/thiazepine-fused [2.2.2] isoquinuclidines is developed. The reaction proceeds through a proline-catalyzed direct Mannich reaction followed by an intramolecular aza-Michael cascade sequence between 2-cyclohexene-1-one and various tricyclic imines, like dibenzoxazepines/thiazepines, as an overall [4 + 2] aza-Diels–Alder reaction. A series of pentacyclic isoquinuclidines have been prepared, with complete endo-selectivity, in good to high yields and excellent enantioselectivity (>99:1). Density functional theory (DFT) calculations further support the observed high stereochemical outcome of the reaction.Item KPF6-Mediated Esterification and Amidation of Carboxylic Acids(ACS, 2022-01) Kumar, AnilA novel KPF6-promoted green method has been developed for the synthesis of esters and amides. A wide range of carboxylic acids and alcohols or amines worked well under the developed reaction conditions, thus providing good to excellent (61–98%) yields of the corresponding esters and amides. The method worked well with bioactive substrates such as cholesterol, levulinic acid, and linoleic acid. Wide substrate scope, operational simplicity, scalability, and sustainability make this protocol a practical and economically attractive approach for the preparation of ester and amides.Item Purification of thermo and acid tolerant extracellular phytase from a new soil isolate of Amycolatopsis vancoresmycina S-12(Elsevier, 2017-07) Bandyopadhyay, DebashisAmycolatopsis vancoresmycina S-12, a member of soil Actinomycetes, was explored regarding its extracellular phytase. The enzyme was recovered from the culture broth by ammonium sulfate fractionation and purified to near homogeneity following dialysis, DEAE Sepharose and Sphadex G-100 column. The enzyme was purified 5.51 fold with a final yield of 14.9%. It was characterized by SDS PAGE, Zymogram, Native PAGE, 2D PAGE as monomeric protein of 53 kDa. and pI 5.4. Peptide mass fingerprinting of MALDI-TOF MS result indicates its phytase nature. Optimum enzyme activity was at 37 °C and at pH 5.4. Optimum stability was at 60 °C and pH 8.0. The enzyme activity is stimulated in presence of Mg2+. The plant growth promotion experiment shows a significant effect, with an increase of 10% root and 25% of shoot length, resulting in a 2.2 fold increase in biomass.Item Manufacturing and Scale-Up of Biotechnology-Derived Products(Springer, 2023-07) Jindal, Anil B.In the last decade, there has been a notable increase in the approval of biotechnology-based pharmaceutical products by regulatory agencies for treating various diseases. Large-scale production of these products is crucial to meet the market demand. However, the complex nature of biological techniques presents challenges in scaling up these products obtained from cell culture techniques. This chapter delves into the typical unit operations involved in the manufacturing of biotechnology-based products and the scale-up considerations required to increase the batch size. It focuses explicitly on cell culture processes and does not include fermentation processes in its discussion.Item Direct Amine-Catalyzed Enantioselective Synthesis of Pentacyclic Dibenzo[b,f][1,4]oxazepine/Thiazepine-Fused Isoquinuclidines along with DFT Calculations(ACS, 2020) Kumar, Indresh; Kumar, DalipA direct protocol for the asymmetric synthesis of dibenzoxazepine/thiazepine-fused [2.2.2] isoquinuclidines is developed. The reaction proceeds through a proline-catalyzed direct Mannich reaction followed by an intramolecular aza-Michael cascade sequence between 2-cyclohexene-1-one and various tricyclic imines, like dibenzoxazepines/thiazepines, as an overall [4 + 2] aza-Diels–Alder reaction. A series of pentacyclic isoquinuclidines have been prepared, with complete endo-selectivity, in good to high yields and excellent enantioselectivity (>99:1). Density functional theory (DFT) calculations further support the observed high stereochemical outcome of the reaction.