Indium(III)-Catalyzed Synthesis of Primary Carbamates and N-Substituted Ureas

Synlett ◽  
2021 ◽  
Author(s):  
Payal Malik ◽  
Isha Jain
Keyword(s):  
Reaction Times ◽  
Nucleophilic Attack ◽  
Chromatographic Purification ◽  
Indium Triflate ◽  
Reaction Proceeds ◽  
Simple Filtration ◽  
Mechanistic Investigations ◽  
Cyclic Alcohols

AbstractAn indium triflate-catalyzed synthesis of primary carbamates from alcohols and urea as an ecofriendly carbonyl source has been developed. Various linear, branched, and cyclic alcohols were converted into the corresponding carbamates in good to excellent yields. This method also provided access to N-substituted ureas by carbamoylation of amines. All the products were obtained by simple filtration or crystallization, without the need for chromatographic purification. Mechanistic investigations suggest that the carbamoylation reaction proceeds through activation of urea by O-coordination with indium, followed by nucleophilic attack by the alcohol or amine on the carbonyl center of urea. The inexpensive and easily available starting materials and catalyst, the short reaction times, and the ease of product isolation highlight the inherent practicality of the developed method.

scholarly journals The Eschenmoser coupling reaction under continuous-flow conditions

2011 ◽  
Vol 7 ◽  
pp. 1164-1172 ◽  
Author(s):  
Sukhdeep Singh ◽  
J Michael Köhler ◽  
Andreas Schober ◽  
G Alexander Groß
Keyword(s):  
Continuous Flow ◽  
Elevated Temperatures ◽  
Reaction Times ◽  
Coupling Reaction ◽  
Flow Chemistry ◽  
Flow Conditions ◽  
Reaction Conditions ◽  
Bond Forming ◽  
Carbon Carbon Bond ◽  
Reaction Proceeds

The Eschenmoser coupling is a useful carbon–carbon bond forming reaction which has been used in various different synthesis strategies. The reaction proceeds smoothly if S-alkylated ternary thioamides or thiolactames are used. In the case of S-alkylated secondary thioamides or thiolactames, the Eschenmoser coupling needs prolonged reaction times and elevated temperatures to deliver valuable yields. We have used a flow chemistry system to promote the Eschenmoser coupling under enhanced reaction conditions in order to convert the demanding precursors such as S-alkylated secondary thioamides and thiolactames in an efficient way. Under pressurized reaction conditions at about 220 °C, the desired Eschenmoser coupling products were obtained within 70 s residence time. The reaction kinetics was investigated and 15 examples of different building block combinations are given.

scholarly journals QUANTUM-CHEMICAL STUDY OF THE REACTION MECHANISM 1,2-ETHANEDIIOL WITH 1,3-DICHLOROPROPENE

2020 ◽  
Vol 2018 (1) ◽  
pp. 56-57
Author(s):  
Elena Chirkina ◽  
Leonid Krivdin ◽  
Nikolay Korchevin
Keyword(s):  
Carbon Atom ◽  
Sulfur Atom ◽  
Density Functional ◽  
Quantum Chemical Study ◽  
Thiol Group ◽  
Chemical Study ◽  
Nucleophilic Attack ◽  
Substitution Product ◽  
Reaction Proceeds ◽  
Theoretical Mechanism

The theoretical mechanism of the interaction of 1,3-dichloropropene with 1,2- ethanedithiol in the system "hydrazine hydrate-KOH" has been proposed by the method of B3LYP / 6- 311 ++ G (d, p) in the framework of the theory of the electron-density functional according to which the reaction proceeds successively in several stages, including the nucleophilic substitution of the chlorine atom present in the sp3-hybridized carbon atom with a sulfur atom to form a mono-substitution product that undergoes a prototropic allylic rearrangement that migrates the double bond to the sulfur atom, followed by closure in the dithiolane cycle due to the nucleophilic attack of the sulfide anion of the second thiol group of the reagent per carbon atom located in the γ-position with respect to the second chlorine atom.

scholarly journals Enantioenriched Quaternary α-Pentafluoroethyl Derivatives of Alkyl 1-Indanone-2-Carboxylates

2020 ◽  
Author(s):  
Albert Granados ◽  
Anna Balleteros ◽  
Adelina Vallribera
Keyword(s):  
Hypervalent Iodine ◽  
Catalytic Method ◽  
Quaternary Centers ◽  
Mild Conditions ◽  
Reaction Proceeds ◽  
Mechanistic Investigations ◽  
Derivatives Of

An electrophilic enantioselective catalytic method for the a-pentafluoroethylation of alkyl 1-indanone-2-carboxylates is described. Under the use of La(OTf)<sub>3</sub> in combination with (<i>S,R</i>)-indanyl-<i>pybox</i> ligand good results in terms of yield and enantioselectivities were achieved (up to 89% <i>ee</i>). The reaction proceeds under mild conditions leading to the formation of enantioenriched quaternary centers. This methodology uses an hypervalent iodine(III)-CF<sub>2</sub>CF<sub>3</sub> reagent and mechanistic investigations are consistent with the involvement of a radical pathway.

scholarly journals THEORETICAL STUDY OF THE REACTION MECHANISM 1,2-ETHANEDIIOL WITH 1,3-DICHLOROPROPENE

2020 ◽  
Vol 2018 (1) ◽  
pp. 68-77
Author(s):  
Elena Chirkina ◽  
Leonid Krivdin ◽  
Nikolay Korchevin
Keyword(s):  
Carbon Atom ◽  
Chlorine Atom ◽  
Sulfur Atom ◽  
Density Functional ◽  
Theoretical Study ◽  
Thiol Group ◽  
Nucleophilic Attack ◽  
Substitution Product ◽  
Reaction Proceeds ◽  
Theoretical Mechanism

The theoretical mechanism of the interaction of 1,3-dichloropropene with 1,2-ethanedithiol in the system "hydrazine hydrate-KOH" has been proposed by the method of B3LYP / 6-311 ++ G (d, p) in the framework of the theory of the electron-density functional according to which the reaction proceeds successively in several stages, including the nucleophilic substitution of the chlorine atom present in the sp3-hybridized carbon atom with a sulfur atom to form a mono-substitution product that undergoes a prototropic allylic rearrangement that migrates the double bond to the sulfur atom, followed by closure in the dithiolane cycle due to the nucleophilic attack of the sulfide anion of the second thiol group of the reagent per carbon atom located in the γ-position with respect to the second chlorine atom.

scholarly journals Natural dolomitic limestone-catalyzed synthesis of benzimidazoles, dihydropyrimidinones, and highly substituted pyridines under ultrasound irradiation

2020 ◽  
Vol 16 ◽  
pp. 1881-1900
Author(s):  
Kumar Godugu ◽  
Venkata Divya Sri Yadala ◽  
Mohammad Khaja Mohinuddin Pinjari ◽  
Trivikram Reddy Gundala ◽  
Lakshmi Reddy Sanapareddy ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Reaction Times ◽  
Ultrasound Irradiation ◽  
Dolomitic Limestone ◽  
Chromatographic Purification ◽  
Green Catalyst ◽  
Edax Analysis ◽  
Substituted Pyridines ◽  
Reaction Profile

Natural dolomitic limestone (NDL) is employed as a heterogeneous green catalyst for the synthesis of medicinally valuable benzimidazoles, dihydropyrimidinones, and highly functionalized pyridines via C–N, C–C, and C–S bond formations in a mixture of ethanol and H2O under ultrasound irradiation. The catalyst is characterized by XRD, FTIR, Raman spectroscopy, SEM, and EDAX analysis. The main advantages of this methodology include the wide substrate scope, cleaner reaction profile, short reaction times, and excellent isolated yields. The products do not require chromatographic purification, and the catalyst can be reused seven times. Therefore, the catalyst is a greener alternative for the synthesis of the above N-heterocycles compared to the existing reported catalysts.

scholarly journals A novel sulfonamide non-classical carbenoid: a mechanistic study for the synthesis of enediynes

2017 ◽  
Vol 15 (46) ◽  
pp. 9895-9902 ◽  
Author(s):  
Theodore O. P. Hayes ◽  
Ben Slater ◽  
Richard A. J. Horan ◽  
Marc Radigois ◽  
Jonathan D. Wilden
Keyword(s):  
Mechanistic Study ◽  
Reaction Proceeds ◽  
Mechanistic Investigations

Alkynyl sulfonamides undergo sequential 1,4- then 1,2-addition/rearrangement with lithium acetylides to yield enediynes in the absence of any promoters or catalysts. Mechanistic investigations suggest that the reaction proceeds via a novel electrophilic carbenoid with distinct reactivity compared to those previously described.

Nucleophilic attack on the carbon–carbon double bond. I. Reaction of primary and secondary amines with 2,2-di(4-nitrophenyl)-1,1-difluoroethene

1986 ◽  
Vol 64 (12) ◽  
pp. 2274-2278 ◽  
Author(s):  
Kenneth T. Leffek ◽  
Urszula Maciejewska
Keyword(s):  
Order Reaction ◽  
Secondary Amines ◽  
Nucleophilic Attack ◽  
Ammonium Ions ◽  
Third Order ◽  
First Order ◽  
Enthalpy Of Activation ◽  
Catalysed Reaction ◽  
Primary And Secondary Amines ◽  
Reaction Proceeds

The reaction of primary and secondary amines with 2,2-di(4-nitrophenyl)-1,1-difluoroethene (1) in acetonitrile solvent gives first 2,2-di(4-nitrophenyl)-1-fluoro-1-aminoethene (2) and then 2,2-di(4-nitrophenyl)-1,1-difluoro-1-aminoethane (3). With excess amine, pseudo-first-order rate constants for the production of 2 were measured, which showed a second-order reaction, together with a catalysed third-order reaction. In addition to the reagent amines, the reaction is also catalysed by tertiary amines and bases such as oxalate and acetate, but not by chloride and perchlorate, nor by ammonium ions. The enthalpy of activation for the reaction of piperidine with 1 in acetonitrile is 3.7 kcalmol−1, but for the catalysed reaction an apparent value of −2.2 kcal mol−1 was obtained. It is concluded that the reaction proceeds via a pre-equilibrium to a zwitterion, followed by another equilibrium giving a carbanion that yields the product (2) by a rate-determining cleavage of the carbon–fluorine bond.

scholarly journals Hydrophosphination using [GeCl{N(SiMe3)2}3] as a pre-catalyst

2020 ◽  
Vol 56 (88) ◽  
pp. 13623-13626 ◽  
Author(s):  
A. N. Barrett ◽  
H. J. Sanderson ◽  
M. F. Mahon ◽  
R. L. Webster
Keyword(s):  
Catalytic Cycle ◽  
Internal Alkynes ◽  
Reaction Proceeds ◽  
Mechanistic Investigations

The hydrophosphination of activated alkenes and internal alkynes is reported using a remarkably simple Ge(iv) pre-catalyst. Preliminary mechanistic investigations indicate that the reaction proceeds via a redox neutral catalytic cycle.

Preparation and Characterization of Hollow MgO/SiO2 Nanocomposites and using as Reusable Catalyst for Synthesis of 1H-Isochromenes

2021 ◽  
Author(s):  
Somaye Mohammadi ◽  
Hossein Naeimi
Keyword(s):  
Heterogeneous Catalyst ◽  
Michael Addition ◽  
Room Temperature ◽  
Aldol Reaction ◽  
Reaction Times ◽  
Active Area ◽  
Reusable Catalyst ◽  
Simple Filtration ◽  
Sio2 Nanocomposites

Abstract In the present study, hollow MgO/SiO2 nanocatalyst with great base properties was made. This heterogeneous catalyst was a synthesis in several steps to create a great active area and decrease the density of the catalyst. The base hollow catalyst framework for the reaction of cyclohexanone, malononitrile and benzaldehyde to the synthesis of 1H-isocromene from Michael addition and aldol reaction at room temperature. All the reaction flowing was excellent in the yield of productand reaction times. At the end of the reaction, the nanocatalyst separated by simple filtration and reuse in several runs elsewhere.

Copper-Catalyzed C(sp3)–H Azidation of 1,3-Dihydro-2H-indol-2-ones Under Mild Conditions

Synlett ◽  
2018 ◽  
Vol 30 (01) ◽  
pp. 109-113 ◽  
Author(s):  
Wen-Ting Wei ◽  
Yan-Yun Liu ◽  
Wen-Hui Bao ◽  
Le-Han Gao ◽  
Wei-Wei Ying ◽  
...  
Keyword(s):  
Biological Activity ◽  
Reaction Times ◽  
Reaction Conditions ◽  
Mild Conditions ◽  
Trimethylsilyl Azide ◽  
Reaction Proceeds ◽  
The Rich ◽  
Enol Tautomer

A simple and economical synthesis of 3-substituted 3-azido-1,3-dihydro-2H-indol-2-ones has been realized under mild conditions through copper-catalyzed C(sp3)–H azidation of the corresponding 1,3-dihydro-2H-indol-2-ones with trimethylsilyl azide. The reaction proceeds by an efficient pathway involving the addition of a N3 radical to the enol tautomer and consecutive C(sp3)−N bond formations. The method is valuable because of its mild reaction conditions, short reaction times, and broad substrate scope, and because of the rich biological activity of the resulting 3-substituted 3-azido-1,3-dihydro-2H-indol-2-one products.

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