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    Assembly of NHC-stabilized 2-hydrophosphasilenes from Si(iv) precursors: a Lewis acid-base complex
    (Royal Society of Chemistry, 2016) Dhara, Debebrata; Mandal, Debdeep; Maiti, Avijit; Yıldız, Cem Burak; Kalita, Pankaj; Chrysochos, Nicolas; Schulzke, Carola; Chandrasekhar, Vadapalli; Jana, Anukul
    NHC-stabilized 2-hydrophosphasilenes are obtained from 1,2-dihydro-2-chlorophosphasilanes as Si(iv) precursors by a NHC-assisted 1,2-elimination of HCl. The NHC-exchange of these compounds is demonstrated as a proof of donor acceptor bonding between NHC and the silicon centre of the “P” moiety. We have also explored the possibility of similar exchanges in NHC-stabilized Si2 and P2 compounds. Theoretical DFT calculations were performed to address the nature of Si-P bonding in the NHC-stabilized 2-hydrophosphasilenes. © The Royal Society of Chemistry.
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    Contrasting reactivity of (boryl)(aryl)lithium-amide with electrophiles: N- vs. p-aryl-C-nucleophilic substitution
    (Royal Society of Chemistry, 2018) Dhara, Debabrata; Vijayakanth, Thangavel; Nayak, Mithilesh Kumar; Kalita, Pankaj; Boomishankar, Ramamoorthy; Yıldız, Cem Burak; Chandrasekhar, Vadapalli; Jana, Anukul
    Herein we report two different reactivity modes of lithium(aryl)(boryl)amide, 4, when it is reacted with chlorosilanes such as SiCl4 and MeSiHCl2, and chlorophosphine, Ph2PCl. Thus, the reaction of lithium(aryl)(boryl)amide, 4, with MeSiHCl2 leads exclusively to an N-substitution product, 6. On the other hand, the reaction of 4 with SiCl4 and Ph2PCl proceeds completely differently affording exclusively p-aryl-C-substitution products, 5 and 7, respectively. © 2018 The Royal Society of Chemistry.
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    Reactivity enhancement of a diphosphene by reversible N-heterocyclic carbene coordination
    (Royal Society of Chemistry, 2018) Dhara, Debabrata; Kalita, Pankaj; Mondal, Subhadip; Narayanan, Ramakirushnan Suriya; Mote, Kaustubh R.; Huch, Volker; Zimmer, Michael; Yıldız, Cem Burak; Scheschkewitz, David; Chandrasekhar, Vadapalli; Jana, Ankul
    Diphosphene TerMesP = PTerMes (1; TerMes = 2,6-Mes2C6H3; Mes = 2,4,6-Me3C6H2) and NHCMe42 (NHCMe4 = 1,3,4,5-tetramethylimidazol-2-ylidene) exist in an equilibrium mixture with the NHCMe4-coordinated diphosphene 3. While uncoordinated 1 is inert to hydrolysis, the NHC adduct 3 readily undergoes hydrolysis to afford a phosphino-substituted phosphine oxide with the liberation of NHCMe4. On this basis, conditions suitable for the catalytic use of NHCMe4 were identified. Similarly, while the hydrogenation of free diphosphene 1 with H3N·BH3 is very slow, 3 reacts instantaneously with H3N·BH3 at room temperature to afford a dihydrodiphosphane. © 2018 The Royal Society of Chemistry.
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    Reactivity of NHC/diphosphene-coordinated Au(i)-hydride
    (Royal Society of Chemistry, 2021) Dhara, Debabrata; Scheschkewitz, David; Chandrasekhar, Vadapalli; Jana, Anuku; Yıldız, Cem B.
    We report the reactivity of isolable Au(i)-hydride stabilized by an NHC-coordinated diphosphene towards substrates containing C-C and N-N multiple bonds (NHC = N-heterocyclcic carbene). Reactions with dimethyl acetylenedicarboxylate and azobenzene lead to a trans-addition of the Au(i)-H across the C-C triple bond and the N-N double bond, respectively. In contrast, the reaction with ethyl diazoacetate affords a gold(i)-hydrazonide as the 1,1-addition product to the terminal nitrogen atom. With phenyl acetylene, the corresponding Au(i)-alkynyl complex is obtained under the elimination of dihydrogen. Strikingly, diphosphene-containing Au(i)-hydride is more reactive - affording different products in some cases - than a related NHC-stabilized Au(i)-hydride without the mediating diphosphene moiety.
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    Öğe
    Reactivity of NHC/diphosphene-coordinated Au(i)-hydride
    (Royal Society of Chemistry, 2021) Dhara, Debabrata; Scheschkewitz, David; Chandrasekhar, Vadapalli; Yıldız, Cem B.; Jana, Anukul
    We report the reactivity of isolable Au(i)-hydride stabilized by an NHC-coordinated diphosphene towards substrates containing C-C and N-N multiple bonds (NHC = N-heterocyclcic carbene). Reactions with dimethyl acetylenedicarboxylate and azobenzene lead to a trans-addition of the Au(i)-H across the C-C triple bond and the N-N double bond, respectively. In contrast, the reaction with ethyl diazoacetate affords a gold(i)-hydrazonide as the 1,1-addition product to the terminal nitrogen atom. With phenyl acetylene, the corresponding Au(i)-alkynyl complex is obtained under the elimination of dihydrogen. Strikingly, diphosphene-containing Au(i)-hydride is more reactive-affording different products in some cases-than a related NHC-stabilized Au(i)-hydride without the mediating diphosphene moiety.