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Rana P, Saini KM, Kaushik B, Solanki K, Dixit R, Sharma RK. Unleashing the photocatalytic potential of a noble-metal-free heteroleptic copper complex-based nanomaterial for an enhanced aza-Henry reaction. Nanoscale 2023; 15:14007-14017. [PMID: 37539685 DOI: 10.1039/d3nr01915b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Abstract
In this work, we fabricated a versatile and noble metal free copper-based heterogeneous photocatalyst, representing a green shift away from precious group metals such as Ir, Ru, Pt, which have been widely utilized as photocatalysts. The successfully synthesized and characterized copper photocatalyst was employed to establish a cross dehydrogenative coupling via C-H activation between tertiary amines and carbon nucleophiles. The highly efficient copper-based photocatalyst was characterized by numerous physico-chemical techniques, which confirmed its successful formation as well as its high activity. Inductively coupled plasma (ICP-OES) analysis revealed that the composite Cu@Xantphos@ASMNPs had a very high loading of 0.423 mmol g-1 of copper. The magnetic Cu@Xantphos@ASMNPs were utilized as a potential heterogeneous photocatalyst for the very facile and regioselective conversion of aryl tetrahydroqinoline to the respective nitroalkyl aryl tetrahydroisoquinoline in high yield using air as an oxidant and methanol as a green solvent with irradiation with visible light under mild reaction conditions. Additionally, the catalyst shows exceptional chemical stability and reusability without any agglomeration even after several cycles of use, which is one of the key features of this material, rendering it a potential candidate from economic and environmental perspectives.
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Affiliation(s)
- Pooja Rana
- Green Chemistry Network Centre, Department of Chemistry, University of Delhi, New Delhi-110007, India.
| | - Kapil Mohan Saini
- Kalindi College, University of Delhi, New Delhi, Delhi-110008, India
| | - Bhawna Kaushik
- Green Chemistry Network Centre, Department of Chemistry, University of Delhi, New Delhi-110007, India.
- Acharya Narendra Dev College, University of Delhi, New Delhi, Delhi-110019, India
| | - Kanika Solanki
- Green Chemistry Network Centre, Department of Chemistry, University of Delhi, New Delhi-110007, India.
- Shyamlal College, University of Delhi, New Delhi, Delhi-1100032, India
| | - Ranjana Dixit
- Green Chemistry Network Centre, Department of Chemistry, University of Delhi, New Delhi-110007, India.
- Ramjas College, University of Delhi, New Delhi-110007, India
| | - Rakesh K Sharma
- Green Chemistry Network Centre, Department of Chemistry, University of Delhi, New Delhi-110007, India.
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Rana P, Kaushik B, Solanki K, Saini KM, Sharma RK. Development of heterogeneous photocatalysts via the covalent grafting of metal complexes on various solid supports. Chem Commun (Camb) 2022; 58:11354-11377. [PMID: 36148784 DOI: 10.1039/d2cc03568e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
To date, remarkable progress has been achieved in the development of photocatalysts owing to their high activity, selectivity, and tunable light absorption in the visible light range. Recently, heterogeneous photocatalytic systems have emerged as potential candidates due to their beneficial attributes (e.g., high surface area, ease of functionalization and facile separation). Herein, we provide a concise overview of the rational design of heterogeneous photocatalysts by grafting photoactive complexes on heterogeneous support matrices via covalent grafting and their detailed characterization techniques, which have been followed by the landmark examples of their applications. Also, major challenges and opportunities in the forthcoming progress of these appealing areas are emphasised.
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Affiliation(s)
- Pooja Rana
- Green Chemistry Network Centre, Department of Chemistry, University of Delhi, New Delhi-110007, India.
| | - Bhawna Kaushik
- Green Chemistry Network Centre, Department of Chemistry, University of Delhi, New Delhi-110007, India.
| | - Kanika Solanki
- Green Chemistry Network Centre, Department of Chemistry, University of Delhi, New Delhi-110007, India.
| | - Kapil Mohan Saini
- Kalindi College, University of Delhi, New Delhi, Delhi 110008, India
| | - R K Sharma
- Green Chemistry Network Centre, Department of Chemistry, University of Delhi, New Delhi-110007, India.
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Saunthwal RK, Saini KM, Grimblat N, Danodia AK, Kumar S, Gandon V, Verma AK. Expedient Access to Polyaromatic Biaryls by Unconventional Ag-Catalyzed Cycloaromatization of Alkynylthiophenes and Au-Catalyzed Double C-H Activation. Org Lett 2022; 24:5018-5022. [PMID: 35799326 DOI: 10.1021/acs.orglett.2c01665] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
An unconventional approach for the regioselective synthesis of polyaromatic biaryls via site-selective Ag-catalyzed twofold electrophilic cycloisomerization followed by Au-catalyzed double C-H activation is described. The developed process allows the synthesis of highly decorated biaryls with excellent regioselectivity. As revealed by DFT computations, the reaction represents a rare example of C1-C5 endo-exo and C1-C6 endo-endo cycloaromatization. The formation of the 6-membered ring is predicted to be the fruit of an uncommon SEAr on a vinyl carbocation.
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Affiliation(s)
| | | | - Nicolas Grimblat
- Laboratoire de Chimie Moléculaire (LCM), CNRS UMR 9168, Ecole Polytechnique, Institut Polytechnique de Paris, route de Saclay, 91128 Palaiseau cedex, France.,Instituto de Química Rosario (IQUIR, CONICET-UNR) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531 (S2002LRK), Rosario, República Argentina
| | | | - Sushil Kumar
- Department of Chemistry, University of Delhi, Delhi-110007, India
| | - Vincent Gandon
- Laboratoire de Chimie Moléculaire (LCM), CNRS UMR 9168, Ecole Polytechnique, Institut Polytechnique de Paris, route de Saclay, 91128 Palaiseau cedex, France.,Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), CNRS UMR 8182, Université Paris-Saclay, Bâtiment 420, 91405 Orsay cedex, France
| | - Akhilesh K Verma
- Department of Chemistry, University of Delhi, Delhi-110007, India.,Institution of Eminence, University of Delhi, Delhi-110007, India
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Affiliation(s)
- Sushmita
- Synthetic Organic Chemistry Research Laboratory Department of Chemistry University of Delhi Delhi 110007 India
| | - Trapti Aggarwal
- Synthetic Organic Chemistry Research Laboratory Department of Chemistry University of Delhi Delhi 110007 India
| | - Kapil Mohan Saini
- Synthetic Organic Chemistry Research Laboratory Department of Chemistry University of Delhi Delhi 110007 India
| | - Akhilesh K. Verma
- Synthetic Organic Chemistry Research Laboratory Department of Chemistry University of Delhi Delhi 110007 India
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Saini KM, Saunthwal RK, Kumar A, Verma AK. Tandem 6π-Azatriene Electrocyclization of Fused Amino-cyclopentenones: Synthesis of Functionalized Pyrrolo- and Indolo-quinoxalines. Org Lett 2021; 23:7586-7591. [PMID: 34543027 DOI: 10.1021/acs.orglett.1c02782] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A tandem 6π-azacyclization approach for the synthesis of diversified pyrrolo/indolo[1,2-a]quinoxalines from amino-cyclopentenones has been developed. The reaction proceeds through a trifluoroacetic-acid-mediated 6π-electrocyclization and concomitant opening of the cyclopentenone ring. The advantageous features of the developed chemistry include transition-metal-free conditions, operational simplicity, and a broad substrate scope. Further X-ray crystallographic studies confirm the assigned structures of the fused heterocycles.
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Affiliation(s)
- Kapil Mohan Saini
- Kalindi College, Department of Chemistry, University of Delhi, Delhi 110008, India
| | - Rakesh K Saunthwal
- Department of Chemistry, University of Illinois at Urbana-Champaign, Champaign 61801, United States
| | - Ankit Kumar
- Department of Chemistry, University of Delhi, Delhi 110007, India
| | - Akhilesh K Verma
- Department of Chemistry, University of Delhi, Delhi 110007, India
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Kumar A, Mishra PK, Saini KM, Verma AK. Base‐Promoted Synthesis of Polysubstituted 4‐Aminoquinolines from Ynones and 2‐Aminobenzonitriles under Transition‐Metal‐Free Conditions. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202100023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Ankit Kumar
- Department of Chemistry University of Delhi Delhi 110007 India
| | - Pawan K. Mishra
- Department of Chemistry University of Delhi Delhi 110007 India
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Saini KM, Saunthwal RK, Sushmita, Verma AK. Synthesis of cyclopentaquinolinone and cyclopentapyridinone from ortho-alkynyl-N-arylaldehyde via superbase-promoted C-N, C-O and C-C bond formation. Org Biomol Chem 2020; 18:5594-5601. [PMID: 32644087 DOI: 10.1039/d0ob01281e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An environmentally benign, transition metal-free, superbase-mediated intramolecular annulation of o-alkynylaldehydes with primary amines forms highly functionalized amino-substituted cyclopentaquinolinones and cyclopentapyridinones via C-N, C-C, and C[double bond, length as m-dash]O bond formation. Contrary to the traditional approaches of ring closures, a different mode of annulation is disclosed. The protocol involves the in situ generations of imine intermediate followed by potassium hydroxide-promoted intramolecular cyclization and subsequent dimethyl sulfoxide induced dehydrogenation leads to the formation of N-heterocycles. X-ray crystallographic studies support the assigned structures of the amino-fused N-heterocycles.
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Sushmita, Aggarwal T, Saini KM, Verma AK. Olefin-Oriented Selective Synthesis of Linear and Branched N-Alkylated Heterocycles by Hydroamination. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000373] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Sushmita
- Department of Chemistry; University of Delhi; 110007 Delhi India
| | - Trapti Aggarwal
- Department of Chemistry; University of Delhi; 110007 Delhi India
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Saini KM, Saunthwal RK, Sushmita, Verma AK. Transition‐Metal‐Free Reverse Reactivity of (2‐Alkynyl)‐Arylaldimines: Assembly of Functionalized Amino‐Indinones. Chemistry 2020. [DOI: 10.1002/chem.201904294] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
| | - Rakesh K. Saunthwal
- Department of ChemistryUniversity of Delhi Delhi 110007 India
- School of ChemistryUniversity of Bristol Bristol BS8 1TS UK
| | - Sushmita
- Department of ChemistryUniversity of Delhi Delhi 110007 India
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Saini KM, Saunthwal RK, Kumar S, Verma AK. On water: iodine-mediated direct construction of 1,3-benzothiazines from ortho-alkynylanilines by regioselective 6-exo-dig cyclization. Org Biomol Chem 2019; 17:2657-2662. [PMID: 30762860 DOI: 10.1039/c9ob00128j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Herein, we report the 6-exo-dig ring closure of ortho-alkynylanilines with readily available aroyl isothiocyanate. An environmentally benign, metal- and base-free, iodine promoted cascade synthesis of highly functionalized (benzo[1,3]thiazin-2-yl)benzimidic acids has been accomplished via in situ generated ortho-alkynylthiourea. The established methodology employs the abundant chemical feedstock of ortho-alkynylanilines and aroyl isothiocyanates and could be applied in the late-stage synthesis of pharmaceutically active 1,3-benzothiazine containing molecules. Furthermore, the discovered protocol exclusively delivers bis (benzo[1,3]thiazin-2-yl)dibenzimidic acid products and preserves the iodo-olefin substitution pattern which can be exploited by further derivatization.
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Affiliation(s)
- Kapil Mohan Saini
- Synthetic Organic Chemistry Research Laboratory, Department of Chemistry, University of Delhi, Delhi-110007, India.
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Saini KM, Saunthwal RK, Kumar S, Verma AK. On Water: Metal-Free Synthesis of Highly Functionalized Benzothiazolylidene from ortho-Haloanilines. J Org Chem 2019; 84:2689-2698. [PMID: 30701974 DOI: 10.1021/acs.joc.8b03107] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An environmentally benign, transition-metal-free organic base promoted one-pot cascade synthesis of highly functionalized benzo[ d]thiazol-2(3 H)-ylidene benzamide in the presence of water was accomplished by three-component reaction of ortho-iodoanilines, acrylates, and aroyl isothiocyanates. The protocol involves the in situ generation of thiourea intermediate followed by triethylamine induced intramolecular SNAr displacement reaction and subsequent Michael addition onto acrylate leads to the formation of benzo[ d]thiazol-2(3 H)-ylidene benzamide. Benzo[ b]thiazole is also generated in good yields using amidation and intramolecular aromatic nucleophilic substitution chemistry. The control experiments support the proposed mechanistic pathway. Further X-ray crystallographic studies confirmed the assigned structures of the fused benzamide.
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Affiliation(s)
- Kapil Mohan Saini
- Synthetic Organic Chemistry Research Laboratory, Department of Chemistry , University of Delhi , Delhi 110007 , India
| | - Rakesh K Saunthwal
- Synthetic Organic Chemistry Research Laboratory, Department of Chemistry , University of Delhi , Delhi 110007 , India
| | - Shiv Kumar
- Synthetic Organic Chemistry Research Laboratory, Department of Chemistry , University of Delhi , Delhi 110007 , India
| | - Akhilesh K Verma
- Synthetic Organic Chemistry Research Laboratory, Department of Chemistry , University of Delhi , Delhi 110007 , India
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Mohan Saini K, Kumar S, Patel M, Saunthwal RK, Verma AK. Trifluoroacetic Acid Mediated One-Pot Synthesis of Furo-Fused Quinoxalines/Pyrazines. European J Org Chem 2017. [DOI: 10.1002/ejoc.201700541] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Sonu Kumar
- Department of Chemistry; University of Delhi; 110007 Delhi India
| | - Monika Patel
- Department of Chemistry; University of Delhi; 110007 Delhi India
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Saunthwal RK, Danodia AK, Saini KM, Verma AK. Ag(i)-Catalyzed cycloisomerization reactions: synthesis of substituted phenanthrenes and naphthothiophenes. Org Biomol Chem 2017; 15:6934-6942. [DOI: 10.1039/c7ob01646h] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Ag-Catalyzed synthesis of substituted phenanthrenes and naphthothiophenes from ortho-alkylated biaryl derivatives via 6-endo-dig intramolecular alkyne–arene coupling has been described.
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Abstract
Unsymmetrical one-pot sequential cross-coupling reactions of sterically hindered tetrabromothiophene with arylboronic acid and an alkyne/alkene to afford selective bi-, tri-, and tetrasubstituted aryl/alkynyl-thiophenes with the aid of a palladium catalyst were described.
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Affiliation(s)
- Kapil Mohan Saini
- Synthetic Organic Chemistry Research Laboratory
- Department of Chemistry
- University of Delhi
- Delhi
- India
| | - Rakesh K. Saunthwal
- Synthetic Organic Chemistry Research Laboratory
- Department of Chemistry
- University of Delhi
- Delhi
- India
| | - Akhilesh K. Verma
- Synthetic Organic Chemistry Research Laboratory
- Department of Chemistry
- University of Delhi
- Delhi
- India
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