Vijay Kumar Das, Ph.D.
Vijay Kumar Das, Ph.D.
Assistant Professor
Assistant Professor
Department of Chemistry, Division of Organic Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, UP, India.
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EDUCATION
TEZPUR UNIVERSITY, TEZPUR, ASSAM, INDIA
Advisor: Prof. Ashim Jyoti Thakur
Ph.D. (Chemical Sciences, ORGANIC CHEMISTRY)
TEZPUR UNIVERSITY, TEZPUR, ASSAM, INDIA
M.Sc. (Applied Chemistry, Medicinal Chemistry Specialization)
NOWGONG COLLEGE, NAGAON, ASSAM, INDIA
B.Sc. (Honors) (Chemistry)
EMPLOYMENT
BANARAS HINDU UNIVERSITY
2020-Present: Assistant Professor
RESEARCH ACTIVITIES
GRANTS FUNDED (Grants received as an independent faculty member from BHU-IoE, UGC and ANRF (SERB).
Total Number of Grants Obtained = 3
Number of Different Agencies = 0
Current and Active
Active Grants received as PI
1. Das, Vijay Kumar (PI). "Toward the synthesis of β-lactam analogous: Exploring catalysis by organometallic nanoparticles." Funded by: BHU (Seed Grant under Institute of Eminence Program), July, 2020 to July, 2023.
2. Das, Vijay Kumar (PI). "Polymer grafted reduced graphene oxide based hypervalent iodine as a novel photocatalysts for C-N bond-forming reactions." Funded by: UGC, November 2021 to November 2023.
RESEARCH PROJECTS
1. Postdoctoral Research
(I) University of KwaZulu Natal, School of Pharmaceutical Science, Catalysis & Peptide Research Unit, Durban, South Africa:
My project at UKZN was to synthesize, characterize and understand the mechanism of action of Organophotocatalyst for activating C-H bonds for the synthesis of Pharmaceutically important molecules (Peptide research).
(II) Indiana University (IU), Department of Chemistry, Bloomington, Indiana, USA:
My project at IU was to synthesize, characterize and understand the mechanism of action of magnetically recoverable graphene-based nanomaterials for catalyzing significant organic reactions. The major achievements of this project include
i. Nanosized Ag, Pd, Ni and Ru have been decorated on the magnetic sheets of graphene/graphene oxide
ii. The graphene/graphene oxide is made magnetic by treating it with Fe(acac)3 to ensure its easy recovery by magnet
iii. Reduction of nitro aromatics and carbonyl compounds using isopropyl alcohol as a transfer hydrogenating agent (Scheme 1 and Scheme 2)catalyzed by Ag-based magnetic graphene/graphene oxide]
The transfer hydrogenation of nitroarenes to aminoarenes using 2-propanol as a hydrogen source and Ag-containing magnetically recoverable catalysts based on partially reduced graphene oxide (pRGO) sheets. X-ray diffraction and X-ray photoelectron spectroscopy data demonstrated that, during the one-pot catalyst synthesis, formation of magnetite nanoparticles (NPs) is accompanied by the reduction of graphene oxide (GO) to pRGO. The formation of Ag0NPs on top of magnetite nanoparticles does not change the pRGO structure. At the same time, the catalyst structure is further modified during the transfer hydrogenation, leading to a noticeable increase of sp2 carbons.
These carbons are responsible for the adsorption of substrate and intermediates, facilitating a hydrogen transfer from Ag NPs and creating synergy between the components of the catalyst. The nitroarenes with electron withdrawing and electron donating substituents allow for excellent yields of aniline derivatives with high regio and chemoselectivity, indicating that the reaction is not disfavored by these functionalities. The versatility of the catalyst synthetic protocol was demonstrated by a synthesis of an Ru-containing graphene derivative based catalyst, also allowing for efficient transfer hydrogenation. Easy magnetic separation and stable catalyst performance in the transfer hydrogenation make this catalyst promising for future applications.
[Reference: Das et al., ACS Applied Materials & Interfaces, 2018, 10 (25), 21356–21364 (Impact Factor: 9.22), https://pubs.acs.org/doi/abs/10.1021/acsami.8b06378]
(III) Tezpur University (TU), Department of Chemical Sciences, Napaam, Assam, India:
My project at TU was to synthesize and characterize polymer-supported Ag nanoparticles using plant extract and apply it to catalyze the conversion of aldehydes into nitriles. In addition to this, the major accomplishment was understanding the mechanism of polymer-supported carbon dot for exclusive hydroxylation of aromatic hydrocarbons at para position under photocatalytic conditions. The major achievements of this project include
(A) The efficient conversion of aldehydes into nitrile (Scheme 3) is catalyzed by aloe vera extract-mediated Ag nanoparticles.
Abstract: Silver nanoparticles prepared by treatment of silver nitrate with Aloe vera(Av) extract in the presence of poly(ethylene glycol) in water (AgNPs-Av, eq. 1) catalyzed the conversion of aldehydes into nitriles (Scheme 3) by treatment with potassium ferrocyanide to give the corresponding aryl nitriles in ≤96% yield (eq. 2).
[Reference: Das et al., Tetrahedron Letters, 2016, 57, 549-553 (Impact Factor: 2.37) https://www.sciencedirect.com/science/article/pii/ S0040403915304986]
(B) Selective (100%) hydroxylation of aromatic hydrocarbons at para position catalyzed byPolymer based carbon dot (Scheme 4).
Abstract: The waterborne polymer/carbon dot nanocompositematerials has been described as an efficient, resourceful and sustainablephotocatalyst for para-selective hydroxylation of substituted aromaticcompounds using H2O2 under UV light (Scheme 4). The polymer matrixand carbon dot generate a synergistic catalytic system. A uniquestructural attribute of the functionalities in this catalytic systemattracts the aromatic substrates into close proximity and activatesthem. Additionally, the flexible molecular box-like structure of thehyperbranched polymer provides the ability for favorable threepointinteraction with several substrates having various sizes bymeans of their multiple force networks and the increased accessibilityof the active sites. The catalyst can be stored on the benchtop for months and is reusable without considerable loss in itsactivity. The reaction was exclusively selective toward parahydroxylation irrespective of the nature of the substituents(electron donating or electron withdrawing) in the aromatic hydrocarbons.Hence, it is one of the most promising catalysts for selectivehydroxylation of substituted aromatic hydrocarbons.
[Reference: Das et al., Green Chemistry, 2017, 19, 4278-4283,(Impact Factor: 10.18), http://pubs.rsc.org/en/content/articlelanding/2017/gc/c7gc01653k#! divAbstract]
(IV) Indian Institute of Technology Guwahati (IITG), Department of Chemistry, Amingaon, Guwahati, Assam, India:
My project in IITG was focused toward an approach for the synthesis of nitrogen and oxygen-containing heterocycles and their application in Natural Product Synthesis. The major achievements of this project include
--- Synthesis of substituted Tetrahydrofurans via Prins Cyclization of Enol Ethers catalyzed by indium triflate
Abstract: Indium triflate can be efficiently used for Prins cyclization of acrylyl enol ethers to give tetrahydrofuran ring stereo and regioselectively in good yields (Scheme 5). The formation of five-membered rings is against the Baldwin’s rule.The method is highlydiastereoselective and gives only cis-2,5-diastereomers. The 3-benzoyl tetrahydrofuran could be converted into N-phenyltetrahydrofuran-3-carboxamide in moderate yield.
[Reference: Journal of Organic Chemistry, 2014, 79, 8592-8598,(Impact Factor 4.80), https://pubs.acs.org/doi/abs/10.1021/jo501197y]
2. Doctoral Research:
The doctoral project at TU was devoted to the development of the “NOSE (Nanoparticles-catalyzed Organic Synthetic Enhancement)” Chemistry approach for the construction of C-C and C-heteroatom bonds in Synthetic Organic chemistry. The catalysts for this purpose were several Nanoparticles which were extensively synthesized and characterized. The achievements of my doctoral research have been outlined below.
(I) N-formylation reaction of amines, indoles, N,N-diformylation of bis-uracil derivatives and synthesis of acetamide derivatives accomplished by Nanosized basic Al2O3 as a catalyst
Abstract: An expeditious, simple, highly efficient, practical and green protocol for the N-formylation of alkyl/arylamines, indole derivatives, N,N-diformylation of bis-uracil derivatives and synthesis of acetamide derivatives catalyzed by nano rod-shaped basic Al2O3 under solvent-freeconditions has been developed (Scheme 6).
The catalyst is efficiently recycled up to the 5thrun, an important point in the domain of green
chemistry. The methodology provides cleaner conversion, shorter reaction times andhigh selectivity which makes the protocol attractive.
[Reference: (a)For NOSE approach coined by us: Das et al., Green Chemistry, 2012, 14, 847-854 (Impact Factor: 10.18), https://www.sciencedirect.com/science/article/pii/S0926860X13000951
(b) Das et al., ISRN Organic Chemistry, 2013, 1-6 (Impact Factor: NA), https://www.ncbi.nlm. nih.gov/ pmc/articles/PMC37 67338/]
(II) Synthesis of amide and amidine derivatives accomplished by Nano MgO as a catalyst under Solvent Free Reaction Condition (SFRC)
Abstract: A clean synthesis of amide derivatives has successfully been accomplished utilizing reusable nano-MgOunder ‘SFRC’ (solvent free reaction condition). The ‘green-ness’ of this protocol makes it a benign alternativefor the large-scale synthesis. In addition to this, nano-MgO also catalyzed synthesis of amidine derivatives under SFRC at 70 °C via NOSE approach. Reusability of the catalyst and shorter reaction time as well as high yields of the products are the advantages ofthis procedure (Scheme 7).
[Reference:(a)Das et al., Applied Catalysis A: General, 2013,456, 118-125 (Impact Factor: 4.52), https://www.sciencedirect.com/science/article/pii/S0926860X13000951; (b) Das et al., Tetrahedron Letters, 2013, 54, 4164-4166 (Impact Factor: 2.37), https://www.sciencedirect.com/science/article/pii/S0040403913008757]
(III) Synthesis of 1-amidoalkyl-2-naphthols under solvent-free reaction condition catalyzed by Piper-betle-shaped nano-S
Abstract: Nano-S prepared by an annealing process showed excellent catalytic activity for the synthesis of 1-amidoalkyl-2-naphthols under the solvent-free reaction condition at 50 °C (Scheme 8). The catalyst could be reused up to the fifth cycle without loss in its action. The green-ness of the present protocol was also measured using green metrics drawing its superiority.
[Reference: Das et al., Journal of Organic Chemistry, 2013, 78, 3361-3366,(Impact Factor: 4.80),https://pubs.acs.org/doi/abs/10.1021/jo302682k]
(IV) Greener oxidation of aldehydes into carboxylic acid derivatives overbio-silica supported Fe2O3as a catalyst
Abstract: A recyclable, robust and highly active Fe2O3nanoparticles supported over bio-silica (DE) i.e. diatomaceousearth (Fe2O3NPs@DE) catalyzed oxidation of aryl/alkyl/heteroaryl aldehydes at room temperature hasbeen developed (Scheme 9). The DE enhanced the catalytic activity of Fe2O3NPs dramatically by serving itself as asmart support.Fe2O3NPs@DE could be
efficiently reused with a slight loss in its catalytic activity. Thenovel supported catalyst is air stable and hence all the reactions can be conducted under aerobic condition.
By the measurement of the “green-ness” using green metrics our protocol emerges as a benign alternative over the existing methodologies.
[Reference: Das et al., Applied Catalysis A: General, 2014, 470, 97-103,(Impact Factor: 4.52),
https://www.sciencedirect.com/science/article/pii/S0926860X1300656X]
(IV) Synthesis of 6-Amino-1,3-dimethyl-5-indolyl-1H-pyrimidine-2,4-dione derivatives from indole and N,N-dimethyl-6-amino uracil catalyzed by nano-Ag
An endeavor has been made towards the synthesis of uracil-basedcompounds in good to high yield catalyzed by nano-Ag at 70 °C upon reacting 6-amino-1,3-dimethyluracil and indole derivatives (Scheme 10).The catalyst was potentially recyclable from fresh up to thethird run.We have developed an efficient protocol for the synthesis ofuracil derivatives catalyzed by heterogeneous, recyclable andmoisture stable nano-Ag. The reaction was optimized with respectto various parameters. We anticipate that this study will findbroad applications for new chemical transformations, includingthe synthesis of challenging bioactive compounds and complexnatural products
[Reference: Das et al., New Journal of Chemistry, 2016, 40, 1935-1939 (Impact Factor: 3.27), http://pubs.rsc.org/en/content/articlelanding/2016/nj/c5nj02134k#!divAbstract]
3. Master degree Research at North East Institute of Science & Technology (formerly RRL Jorhat), Jorhat, Assam, India:
The achievement of master’s degree project involved; Synthesis of quinolines and fused polycyclic quinolones via simple Friedlandler annulation reaction of 2-amino aryl ketones with carbonyl compound catalyzed by zinc triflate under solvent free condition. An environmentally friendly and highly efficient method for the synthesis of quinolines and fused polycyclic quinolines has been developed by a simple Friedlandler annulation reaction of 2-amino aryl ketones with carbonyl compound in presence of zinc triflate under solvent free condition zinc triflate has attracted our attention, as it is inexpensive and can be readily prepared from commercially available trifluoromethanesulfonic acid and zinc carbonate in methanol. Surprisingly this mild Lewis acid which has some distinct difference from other metal triflates have been less investigated in comparison with other extensively studied lanthanide and transition metal triflates. More recently, this reaction is often carried out in polar solvents such as acetonitrile, THF, DMF & DMSO leading to tedious work up procedures. The main disadvantage of most of the existing method is that the catalysts are destroyed in the work up procedure and cannot be recovered or re used. Hence, the development of simple, convenient & environmentally benign approaches for the synthesis of quinolines is still desirable.
**The organic compounds synthesized are characterized by their Rf values, physical appearance, melting/boiling point, FTIR spectra, 1H and 13C NMR spectra, GC/LC-MS, and elemental analyses and confirmed by comparing these data with those reported ones. The nanomaterials in every case were characterized by several techniques such as SEM, EDX, XRD, TEM, SAED, DLS, XPS, FTIR spectroscopy, and BET analyses.
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