Browsing by Author "Shiv Chand"

Now showing 1 - 13 of 13

A Practical Copper Catalyzed N-Arylation of Amines Using Aryl Triazenes as Aryl Source
(Wiley-Blackwell, 2019) Shiv Chand; Saurabh Kumar; Rahul Singh; Krishna Nand Singh
An efficient copper-catalyzed synthesis of N-arylated amines has been developed via cross-coupling of amines with aryl triazenes. The methodology is endowed with broad substrate scope, high yield, and significant functional group tolerance. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Copper-Catalyzed Thiolation of Hydrazones with Sodium Sulfinates: A Straightforward Synthesis of Benzylic Thioethers
(American Chemical Society, 2023) Anand Kumar Pandey; Shiv Chand; Anup Kumar Sharma; Krishna Nand Singh
A facile and sustainable protocol for the thiolation of hydrazones with sodium sulfinates has been developed in the presence of CuBr2 and DBU in DMF to afford diverse benzylic thioethers. Control experiments reveal a radical pathway involving a thiyl radical as a key intermediate. © 2022 American Chemical Society.
Domino Reaction of Isatins with α-Oxoketene-N,S-acetals: An Efficient Synthesis of Pyrrolo[3,4-c]quinoline-1,3-diones and 2,3-Dihydro-1H-pyrrolo[3,4-c]quinolin-1-ones
(John Wiley and Sons Inc, 2021) Anup Kumar Sharma; Anjali Jaiswal; Shiv Chand; Krishna Nand Singh
A straightforward synthesis of pyrrolo[3,4-c]quinoline-1,3-diones and 2,3-dihydro-1H-pyrrolo[3,4-c]quinolin-1-ones has been accomplished by the cascade reaction of isatins with α-oxoketene-N,S-acetals using BF3 ⋅ Et2O in DMSO/toluene at 110 °C. The reaction offers an easy access to biologically important tricyclic N-heterocycles via C−C/C−X bond formation. © 2021 Wiley-VCH GmbH
Easy access to α-carbonyl sulfones using cross-coupling of α-aryl-α-diazoesters with sulfonyl hydrazides
(Royal Society of Chemistry, 2022) Anup Kumar Sharma; Shiv Chand; Anand Kumar Pandey; Krishna Nand Singh
A facile synthesis of α-carbonyl sulfones has been accomplished by the cross-coupling of α-aryl-α-diazoesters with sulfonyl hydrazides in the presence of CuI and DBU. The reaction employs inexpensive and bench stable sulfonyl hydrazides as a sulfonyl source, and facilitates the migratory insertion with α-aryl-α-diazoesters under mild reaction conditions. © 2023 The Royal Society of Chemistry.
Electro-oxidative coupling of Bunte salts with aryldiazonium tetrafluoroborates: a benign access to unsymmetrical sulfoxides
(Royal Society of Chemistry, 2023) Saurabh Kumar; Shiv Chand; Krishna Nand Singh
An electrochemical strategy for the synthesis of unsymmetrical sulfoxides has been explored using Bunte salts and aryldiazonium tetrafluoroborates under constant current electrolysis at room temperature. In addition to being eco-safe and using mild conditions, the present protocol is free from the use of metal/oxidant, and is endowed with a broad substrate scope and good functional group tolerance. © 2024 The Royal Society of Chemistry.
Eosin-Y-Catalyzed Photoredox C−S Bond Formation: Easy Access to Thioethers
(John Wiley and Sons Ltd, 2019) Shiv Chand; Anand Kumar Pandey; Rahul Singh; Saurabh Kumar; Krishna Nand Singh
An operationally simple Eosin Y catalyzed sulfenylation of hydrazones has been realized to afford a range of thioethers under visible light. The methodology provides high yields of thioethers under ambient conditions employing readily available and inexpensive starting materials. The reaction has broad substrate scope and is compatible with various functional groups. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Iodine Catalyzed Sulfenylation of Sodium Sulfinates Using Arenediazonium Tetrafluoroborate/CS2 Combination
(John Wiley and Sons Inc, 2022) Anand Kumar Pandey; Shiv Chand; Anup Kumar Sharma; Krishna Nand Singh
An approach to unsymmetrical thiosulfonates has been developed using sulfenylation of sodium sulfinates by arenediazonium tetrafluoroborate/CS2 combination with iodine as catalyst. The reaction is simple, high yielding, scalable, and proceeds smoothly with good substrate scope and functional group tolerance. © 2022 Wiley-VCH GmbH.
Iodine-Catalyzed Synthesis of 3-Arylthioindoles Employing a 1-Aryltriazene/CS2 Combination as a New Sulfenylation Source
(American Chemical Society, 2020) Anand Kumar Pandey; Shiv Chand; Rahul Singh; Saurabh Kumar; Krishna Nand Singh
A practical approach for the regioselective synthesis of 3-arylthioindoles has been accomplished using a combination of 1-aryltriazene/CS2 as a new sulfenylation source. The methodology employs molecular iodine as a catalyst and is compatible with a variety of structurally diverse reactants. Copyright © 2020 American Chemical Society.
Metal-Free Decarboxylative Cyanomethylation of β-Aryl/Heteroaryl Substituted α,β-Unsaturated Carboxylic Acids to γ-Ketonitriles
(American Chemical Society, 2024) Shiv Chand; Saurabh Kumar; Anup Kumar Sharma; Krishna Nand Singh
A decarboxylative cyanomethylation of β-aryl/heteroaryl substituted α,β-unsaturated carboxylic acids has been accomplished via C(sp3)-H activation of alkyl nitriles to afford diverse γ-ketonitriles by making use of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and tert-butyl hydroperoxide (TBHP). The present report offers a metal-free approach and is featured with a broad substitution pattern and functional group compatibility. © 2024 American Chemical Society.
Synthesis of unsymmetrical ketones via dual catalysed cross-coupling of α,β-unsaturated carboxylic acids with aryldiazonium salts
(Royal Society of Chemistry, 2023) Shiv Chand; Anup Kumar Sharma; Anand Kumar Pandey; Krishna Nand Singh
A visible light-enabled synthesis of unsymmetrical ketones has been accomplished by the cross-coupling of α,β-unsaturated carboxylic acids and aryldiazonium salts embracing a synergistic eosin Y and Co(OAc)2·4H2O catalysis. The reaction involves decarboxylative aerobic C C bond cleavage, and is endowed with the creation of new C-C and C-O bonds with good substrate scope. © 2023 The Royal Society of Chemistry.
Tandem Synthesis of Polysubstituted Pyrroles via Cu(I)-Catalyzed Cyclization of Ketene N,S-Acetals with β-Ketodinitriles
(American Chemical Society, 2025) Anup Kumar Sharma; Mahesh Kumar; Shiv Chand; Krishna Nand Singh
A new approach to multifunctionalized pyrroles has been explored by the tandem cyclization of α-oxoketene-N,S-acetals with β-ketodinitriles using Cu(MeCN)4BF4 and Ag2CO3 in toluene under reflux conditions. The reaction involves C-C/C-N bond creation, and is assumed to proceed via enamine formation, intramolecular cyclization, and rearrangement. The potential of the methodology has also been demonstrated for a gram-scale reaction as well as for some useful organic transformations. The reaction offers a practical pathway to achieve polysubstituted pyrroles with broad substrate scope and good functional group tolerance. © 2025 American Chemical Society.
Visible-Light Photoredox-Catalyzed Synthesis of trans-Oxiranes via Decarboxylative Stereospecific Epoxidation of trans-Cinnamic Acids by Aryldiazonium Salts
(American Chemical Society, 2022) Shiv Chand; Anup Kumar Sharma; Anand Kumar Pandey; Krishna Nand Singh
An efficient visible-light-induced synthesis of trans-oxiranes has been accomplished via decarboxylative stereospecific epoxidation of trans-cinnamic acids by aryldiazonium salts using CuCl, eosin Y, TBHP, and DBU. The reaction is facile, straightforward, and endowed with good functional group tolerability and a good substrate scope. © 2022 American Chemical Society.
Visible-Light-Induced Photocatalytic Oxidative Decarboxylation of Cinnamic Acids to 1,2-Diketones
(American Chemical Society, 2021) Shiv Chand; Anand Kumar Pandey; Rahul Singh; Krishna Nand Singh
A concerted metallophotoredox catalysis has been realized for the efficient decarboxylative functionalization of α,β-unsaturated carboxylic acids with aryl iodides in the presence of perylene bisimide dye to afford 1,2-diketones. © 2021 American Chemical Society.