Bicyclic (Alkyl)(Amino)Imine-Anchored Diphosphine and Its Radical Cation Ritu Yadav, Subrata Kundu Inorganic Chemistry, 2026 We report the synthesis of a new carbene-based imino ligand, [(BICAAC)N – ], derived from the highly amphiphilic bicyclic (alkyl)(amino)carbene (BICAAC) through a classical Staudinger reaction. (BICAAC)NH exhibits a high proton affinity (263.0 kcal/mol), indicating strong basicity. Subsequently, a series of phosphines was synthesized from [(BICAAC)N – ], and their structures were characterized by single-crystal X-ray diffraction and multinuclear NMR spectroscopy. Reduction of (BICAAC)N–P(Br)–Tipp (Tipp = 2,4,6-triisopropylphenyl) with KC 8 afforded a diphosphine compound featuring a P–P single bond, which remained stable in solution even at elevated temperatures. Single-electron oxidation of this diphosphine yielded a persistent radical cation ( 6 • + ), as confirmed by EPR spectroscopy and DFT studies. DFT analysis reveals that the unpaired electron in 6 • + is delocalized over the two BICAAC–imino frameworks and the P–P bond.
Stable Ambiphilic Bis(N-Heterocyclic Imino)-Substituted Terminal Olefin and Its Diazoolefin Derivative Exhibits Unusual Dimerization Bindusagar Das, Dhananjay, Aryan Chauhan, Ritu Yadav, Ankita Sharma, Chinmoy Majumder, Tarak Karmakar, Subrata Kundu Chemistry A European Journal, 2026 In this article, we report a novel bis(N‐heterocyclic imino) terminal olefin, [{(CAAC)N} 2 C═CH 2 ] [CAAC = cyclic (alkyl)(amino)carbene], which exhibits reactivity distinct from traditional N‐heterocyclic olefins. The use of the (CAAC)–derived ambiphilic N‐heterocyclic imino fragment {(CAAC)N‒} was crucial in imparting the unique properties of [{(CAAC)N} 2 C═CH 2 ]. The imino groups act as strong electron donors, rendering the terminal olefin polar through π‐delocalization, whereas the carbenic carbon of CAAC introduces an electrophilic site into the imino substituent. This combination results in an inherently ambiphilic olefin that displays unusual reactivity. Specifically, the reaction of [{(CAAC)N} 2 C═CH 2 ] with tosyl azide, under varying stoichiometric conditions, furnished four distinct nitrogen‐rich compounds, including two unprecedented nitrogen‐containing heterocycles. Quantum‐chemical calculations were carried out to elucidate the bonding features of the ambiphilic bis‐imino terminal olefin as well as the newly formed heterocycles.
Unraveling the Photo-Oxygenation Path of a Cyclic Enamine: Structural Insights into Intermediates Chinmoy Majumder, Bindusagar Das, Ritu Yadav, Ankita Sharma, Ayantika Das, Dwipa Barman, Subrata Kundu Journal of Organic Chemistry, 2025 In this study, we report the activation of molecular oxygen by 2,3-dihydropyrrole in endoperoxide mode. The endoperoxide is converted to a 1,4-dioxane derivative upon decomposition. This reaction proceeded stepwise without the use of any catalyst. Additionally, we isolated several intermediates that were characterized by single-crystal X-ray diffraction. Notably, one of the intermediates represents the first example of a structurally characterized 8-membered cyclic organic peroxide containing two endoperoxide groups and the direct conversion of an enamine to a dioxane has not been documented in the existing literature.
Cyclic (Alkenyl)(Amino)Carbene (SMeCAenAC): Introducing a Member to the Cyclic (Alkyl)(Amino)Carbenes Family Featuring a Narrow Energy Gap Chinmoy Majumder, Ankita Sharma, Bindusagar Das, Ritu Yadav, Subrata Kundu Journal of the American Chemical Society, 2025 Herein, we report the carbene-like activity of a nonisolable, highly ambiphilic cyclic (alkenyl)(amino)carbene (SMeCAenAC, 3), which is stabilized as [(SMeCAenAC)(H)N(SiMe3)2] (4). This protected form (4) is stable in air and moisture. Compound 4 can be used as a carbene source through deamination upon heating to 130-140 °C. Moreover, density functional theory (DFT) calculations indicate that SMeCAenAC has the smallest singlet-triplet gap (37.05 kcal/mol) and a narrow highest occupied molecule orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap (3.92 eV) among the cyclic (alkyl)(amino)carbenes (CAACs). The precursor of carbene (3) can be synthesized on a multigram scale with a good yield. Moreover, the SMeCAenAC-coordinated copper complex showed excellent efficiency in the catalytic addition of phenols to electron-deficient olefins. This study also highlights that [SMeCAenAC-H]OTf can be used for metal-free catalysis, a property uniquely characteristic of an ambiphilic carbene, even though the formation of free SMeCAenAC (3) was not achieved.
Synthesis of Cyclic (Alkyl)(amino)carbene-Stabilized Copper-Iron Heterobimetallic Complexes and Their Application in Pyridine Hydroboration Ankita Sharma, Vikas Tiwari, Ritu Yadav, Bindusagar Das, Chinmoy Majumder, Ayantika Das, Tarak Karmakar, Subrata Kundu Organometallics, 2024 In this report, we synthesized heterobimetallic complexes supported by cyclic and bicyclic (alkyl)(amino)carbenes (CAAC and Et BICAAC) [( Me2 CAAC)CuFe(η 5 -C 5 H 5 )(CO) 2 ]( 1 ) and [( Et BICAAC)CuFe(η 5 -C 5 H 5 )(CO) 2 ] ( 2 ), respectively, featuring an iron–copper bond. Complex 1 demonstrates catalytic activity for selective 1,4-hydroboration reactions of pyridine derivatives. Detailed computational studies provide additional insights into the electronic structure of complexes 1 and 2 and elucidate the catalytic pathway.
Bicyclic (alkyl)(amino)carbenes (BICAACs): synthesis, characteristics, and applications Ankita Sharma, Unnikrishnan Nair K, Subrata Kundu Dalton Transactions, 2024 This review covers the synthesis, characterization, and reactivity of bicyclic(alkyl)(amino)carbenes (BICAACs) and outlines the diverse applications of BICAACs in organometallic chemistry, metal-free catalysis, and main-group chemistry.
Air and Water Stable Bicyclic (Alkyl)(Amino)Carbene Stabilized Phosphenium Cation: Reactivity and Selective Fluoride Ion Affinity Ritu Yadav, Ankita Sharma, Bindusagar Das, Chinmoy Majumder, Ayantika Das, Saumik Sen, Subrata Kundu Chemistry A European Journal, 2024 The synthesis and reactivity of an air and water stable Bicyclic (alkyl)(amino)carbene (BICAAC) stabilized phosphenium cation (1) is reported. Air and water stable phosphenium cation are rare in the literature. Compound 1 is obtained by reaction of BICAAC with Ph2PCl in THF followed by anion exchange with LiOTf. The reduction and oxidation of 1 yielded corresponding α‐radical phosphine species (2) and BICAAC stabilized phosphenium oxide (3) respectively. All compounds are well characterized by single crystal X‐ray diffraction studies. The Lewis acidity of compounds 1 and 3 are determined by conducting fluoride ion affinity experiments using UV‐Vis spectrophotometry and multinuclei NMR spectroscopy. Compounds 1 and 3 exhibited selective binding to fluoride anion but did not interact with other halides (Cl− and Br−). Quantum chemical calculations were performed to understand the structure and nature of bonding interactions in these compounds, as well as to comprehend the specific bonding affinity to fluoride over other halide ions.
Bicyclic (alkyl)(amino)carbene (BICAAC)-supported phosphinidenes Ritu Yadav, Bindusagar Das, Ashi Singh, Anmol, Ankita Sharma, Chinmoy Majumder, Subrata Kundu Dalton Transactions, 2023 This paper provides the synthesis, structure, and bonding analysis of three halo-phosphinidenes and a bis-phosphinidene stabilized by a bicyclic (alkyl)(amino)carbene (BICAAC).
A Carbene-Stabilized Boryl-Phosphinidene Samir Kumar Sarkar, Subrata Kundu, Mohd Nazish, Johannes Kretsch, Regine Herbst‐Irmer, Dietmar Stalke, Parameswaran Parvathy, Pattiyil Parameswaran, Herbert W. Roesky Chemistry A European Journal, 2022
Isolation of base stabilized fluoroborylene and its radical cation Samir Kumar Sarkar, Mujahuddin M. Siddiqui, Subrata Kundu, Munmun Ghosh, Johannes Kretsch, Peter Stollberg, Regine Herbst-Irmer, Dietmar Stalke, A. Claudia Stückl, Brigitte Schwederski, Wolfgang Kaim, Sagar Ghorai, Eluvathingal D. Jemmis, Herbert W. Roesky Dalton Transactions, 2019
Organosilicon Radicals with Si-H and Si-Me Bonds from Commodity Precursors Subrata Kundu, Prinson P. Samuel, Soumen Sinhababu, Anna V. Luebben, Birger Dittrich, Diego M. Andrada, Gernot Frenking, A. Claudia Stückl, Brigitte Schwederski, Alexa Paretzki, Wolfgang Kaim, Herbert W. Roesky Journal of the American Chemical Society, 2017
An Electrophilic Carbene-Anchored Silylene–Phosphinidene Subrata Kundu, Bin Li, Johannes Kretsch, Regine Herbst-Irmer, Diego M. Andrada, Gernot Frenking, Dietmar Stalke, Herbert W. Roesky Angewandte Chemie International Edition, 2017
A Stable Neutral Radical in the Coordination Sphere of Aluminum Bin Li, Subrata Kundu, A. Claudia Stückl, Hongping Zhu, Helena Keil, Regine Herbst-Irmer, Dietmar Stalke, Brigitte Schwederski, Wolfgang Kaim, Diego M. Andrada, Gernot Frenking, Herbert W. Roesky Angewandte Chemie International Edition, 2017
An unprecedented 1,4-diphospha-2,3-disila butadiene (-P[double bond, length as m-dash]Si-Si[double bond, length as m-dash]P-) derivative and a 1,3-diphospha-2-silaallyl anion, each stabilized by the amidinate ligand Chemical Communications Cambridge England, 2016
Cyclophosphazene- and cyclocarbophosphazene-based ligands Indian Journal of Chemistry Section A Inorganic Physical Theoretical and Analytical Chemistry, 2012
Unraveling the Photo-Oxygenation Path of a Cyclic Enamine: Structural Insights into Intermediates C Majumder, B Das, R Yadav, A Sharma, A Das, D Barman, S Kundu The Journal of Organic Chemistry 90 (35), 12316-12322 , 2025 2025
Cyclic (Alkenyl)(Amino)Carbene ( SMe CA en AC): Introducing a Member to the Cyclic (Alkyl)(Amino)Carbenes Family Featuring a Narrow Energy Gap C Majumder, A Sharma, B Das, R Yadav, S Kundu Journal of the American Chemical Society 147 (8), 6905-6913 , 2025 2025 Citations: 10
Bicyclic (alkyl)(amino) carbenes (BICAACs): synthesis, characteristics, and applications A Sharma, U N. K, S Kundu Dalton Transactions , 2025 2025 Citations: 9
Synthesis of Cyclic (Alkyl)(amino) carbene-Stabilized Copper–Iron Heterobimetallic Complexes and Their Application in Pyridine Hydroboration A Sharma, V Tiwari, R Yadav, B Das, C Majumder, A Das, T Karmakar, ... Organometallics 43 (23), 3054-3061 , 2024 2024 Citations: 6
Air and Water Stable Bicyclic (Alkyl)(Amino) Carbene Stabilized Phosphenium Cation: Reactivity and Selective Fluoride Ion Affinity R Yadav, A Sharma, B Das, C Majumder, A Das, S Sen, S Kundu Chemistry–A European Journal 30 (62), e202401730 , 2024 2024 Citations: 7
Transition‐Metal‐Free Dehydropolymerization of Phosphine–Boranes at Ambient Temperature MA Wiebe, S Kundu, EA LaPierre, BO Patrick, I Manners Chemistry–A European Journal 29 (2), e202202897 , 2023 2023 Citations: 8
Bicyclic (alkyl)(amino) carbene (BICAAC)-supported phosphinidenes R Yadav, B Das, A Singh, A Sharma, C Majumder, S Kundu Dalton Transactions 52 (45), 16680-16687 , 2023 2023 Citations: 6
Cyclic (alkyl)(amino) carbene (CAAC)-and bicyclic (alkyl)(amino) carbene (BICAAC)-derived glyoxal radical cations with excellent stability B Das, R Yadav, A Sharma, T Karmakar, S Kundu Chemical Communications 59 (35), 5285-5288 , 2023 2023 Citations: 8
Understanding cyclic (alkyl)(amino) carbene–copper complex catalysed N–H and O–H bond addition to electron deficient olefins A Tyagi, S Mondal, V Tiwari, T Karmakar, S Kundu Chemical Communications 59 (1), 110-113 , 2023 2023 Citations: 15
Modulation of proteasome activity by curcumin and didemethylcurcumin TK Khan, Y You, TJ Nelson, S Kundu, SK Pramanik, J Das Journal of Biomolecular Structure and Dynamics 40 (18), 8332-8339 , 2022 2022 Citations: 13
A Carbene‐Stabilized Boryl‐Phosphinidene S Kumar Sarkar, S Kundu, M Nazish, J Kretsch, R Herbst‐Irmer, D Stalke, ... Chemistry–A European Journal 28 (31), e202200913 , 2022 2022 Citations: 4
Phosphorus radicals and radical ions B Das, A Makol, S Kundu Dalton Transactions 51 (33), 12404-12426 , 2022 2022 Citations: 29
Base-stabilized formally zero-valent mono and diatomic molecular main-group compounds R Yadav, S Sinhababu, R Yadav, S Kundu Dalton Transactions 51 (6), 2170-2202 , 2022 2022 Citations: 32
Pincer‐Type Ligand‐Assisted Catalysis and Small‐Molecule Activation by non‐VSEPR Main‐Group Compounds S Kundu Chemistry - An Asian Journal 15 (20), 3209-3224 , 2020 2020 Citations: 60
Reactions of Amidinate-Supported Silylene with Organoboron Dihalides J Li, Y Liu, S Kundu, H Keil, H Zhu, R Herbst-Irmer, D Stalke, ... Inorganic Chemistry , 2020 2020 Citations: 28
HAlCl 2 and H 2 AlCl as Precursors for the Preparation of Compounds with Four- and Five-Coordinate Aluminum M Zhong, Y Liu, S Kundu, N Graw, J Li, Z Yang, R Herbst-Irmer, D Stalke, ... Inorganic Chemistry 58 (16), 10625-10628 , 2019 2019 Citations: 15
Luminescent Pyrene-Decorated Organotin Compounds: Observation of Monomer and Excimer Emission MD Pandey, RK Metre, S Kundu, B Mahanti, A Kumar, K Gopal, ... Cryst. Growth Des 2019 (19), 1888–1895 , 2019 2019 Citations: 13
Cyclic Alkyl(amino) Carbene-Stabilized Monoradicals of Organosilicon(IV) Compounds with Small Substituents W Li, S Kundu, C Köhler, J Li, S Dutta, Z Yang, D Stalke, RA Herbst-Irmer, ... Organometallic 38 (9), 1939-1945 , 2019 2019 Citations: 8
Stable cyclic (alkyl)(amino)carbene (cAAC) radicals with main group substituents S Kundu, S Sinhababu, V Chandrasekhar, HW Roesky Chem. Sci. 2019 , 2019 2019 Citations: 180
Phosphonate-assisted tetranuclear lanthanide assemblies: observation of the toroidic ground state in the TbIII analogue S Biswas, P Kumar, A Swain, T Gupta, P Kalita, S Kundu, G Rajaraman, ... Dalton Trans., , 2019 2019 Citations: 17
MOST CITED SCHOLAR PUBLICATIONS
Stable cyclic (alkyl)(amino)carbene (cAAC) radicals with main group substituents S Kundu, S Sinhababu, V Chandrasekhar, HW Roesky Chem. Sci. 2019 , 2019 2019 Citations: 180
The Structure of the Carbene Stabilized Si 2 H 2 May Be Equally Well Described with Coordinate Bonds as with Classical Double Bonds C Mohapatra, S Kundu, AN Paesch, R Herbst-Irmer, D Stalke, ... Journal of the American Chemical Society 138 (33), 10429-10432 , 2016 2016 Citations: 104
A stable neutral radical in the coordination sphere of aluminum B Li, S Kundu, AC Stückl, H Zhu, H Keil, R Herbst‐Irmer, D Stalke, ... Angewandte Chemie International Edition 56 (1), 397-400 , 2017 2017 Citations: 89
Decanuclear Ln 10 Wheels and Vertex‐Shared Spirocyclic Ln 5 Cores: Synthesis, Structure, SMM Behavior, and MCE Properties S Das, A Dey, S Kundu, S Biswas, RS Narayanan, S Titos‐Padilla, ... Chemistry–A European Journal 21 (47), 16955-16967 , 2015 2015 Citations: 76
Pincer‐Type Ligand‐Assisted Catalysis and Small‐Molecule Activation by non‐VSEPR Main‐Group Compounds S Kundu Chemistry - An Asian Journal 15 (20), 3209-3224 , 2020 2020 Citations: 60
An Electrophilic Carbene-Anchored Silylene–Phosphinidene S Kundu, B Li, J Kretsch, R Herbst-Irmer, DM Andrada, G Frenking, ... Angew. Chem. Int. Ed 2017 (56), 4219-4223 , 2017 2017 Citations: 60
Comparison of Two Phosphinidenes Binding to Silicon(IV)dichloride as well as to Silylene HWR Subrata Kundu, Soumen Sinhababu, Mujahuddin M Siddiqui, Anna V Luebben ... Journal of the American Chemical Society , 2018 2018 Citations: 54
Synthesis and characterization of Lewis base stabilized mono-and di-organo aluminum radicals S Kundu, S Sinhababu, S Dutta, T Mondal, D Koley, B Dittrich, ... Chemical Communications 53 (76), 10516-10519 , 2017 2017 Citations: 53
Reagent for Introducing Base-Stabilized Phosphorus Atoms into Organic and Inorganic Compounds S Kundu, S Sinhababu, AV Luebben, T Mondal, D Koley, B Dittrich, ... J. Am. Chem. Soc. 140 (1), 151–154 , 2018 2018 Citations: 51
Two Structurally Characterized Conformational Isomers with Different C−P Bonds S Roy, KC Mondal, S Kundu, B Li, CJ Schürmann, S Dutta, D Koley, ... Chem. Eur. J. 2017 , 2017 2017 Citations: 51
Bulky aminotroponiminate-stabilized germylene monochloride and its alkyne derivatives RK Siwatch, S Kundu, D Kumar, S Nagendran Organometallics 30 (7), 1998-2005 , 2011 2011 Citations: 51
An open route to asymmetric substituted Al–Al bonds using Al(I)- and Al(III)-precursors B Li, S Kundu, H Zhu, H Keil, R Herbst-Irmer, D Stalke, G Frenking, ... Chem. Commun. 2017 (54), 2543-2546 , 2017 2017 Citations: 50
Heterometallic Heptanuclear [Cu 5 Ln 2 ] (Ln = Tb, Dy, and Ho) Single-Molecule Magnets Organized in One-Dimensional Coordination Polymeric Network A Dey, S Das, S Kundu, A Mondal, M Rouzieres, C Mathoniere, R Clerac, ... Inorganic Chemistry 56 (23), 14612-14623 , 2017 2017 Citations: 34
Organosilicon Radicals with Si–H and Si–Me Bonds from Commodity Precursors S Kundu, PP Samuel, S Sinhababu, AV Luebben, B Dittrich, DM Andrada, ... J. Am. Chem. Soc 2017 , 2017 2017 Citations: 33
Base-stabilized formally zero-valent mono and diatomic molecular main-group compounds R Yadav, S Sinhababu, R Yadav, S Kundu Dalton Transactions 51 (6), 2170-2202 , 2022 2022 Citations: 32
Silanylidene and Germanylidene Anions: Valence Isoelectronic Species to the Well‐studied Phosphinidene AM Herbert W Roesky, Mujahuddin Siddiqui, Soumen Sinhababu, Subrata Kundu ... Angew. Chem. Int. Ed 57 (36), 11776-11780 , 2018 2018 Citations: 32
Isolation of base stabilized fluoroborylene and its radical cation SK Sarkar, MM Siddiqui, S Kundu, M Ghosh, J Kretsch, P Stollberg, ... Dalton Transactions 48 (24), 8551-8555 , 2019 2019 Citations: 30
A route to base coordinate silicon difluoride and the silicon Trifluoride radical S Sinhababu, S Kundu, AN Paesch, R Herbst‐Irmer, D Stalke, ... Chemistry–A European Journal 24 (6), 1264-1268 , 2018 2018 Citations: 30
Linear, Edge‐Sharing Heterometallic Trinuclear [CoII–LnIII–CoII](LnIII= GdIII, DyIII, TbIII, and HoIII) Complexes: Slow Relaxation of Magnetization in the DyIII Derivative V Chandrasekhar, S Das, A Dey, S Hossain, S Kundu, E Colacio European Journal of Inorganic Chemistry 2014 (2), 397-406 , 2014 2014 Citations: 30
Phosphorus radicals and radical ions B Das, A Makol, S Kundu Dalton Transactions 51 (33), 12404-12426 , 2022 2022 Citations: 29
