scholarly journals Direct Diels-Alder reaction of chitin derived 3-acetamido-5-acetylfuran

2022 ◽  
Author(s):  
Rafael Gomes ◽  
Juliana Pereira ◽  
João Ravasco ◽  
João Vale ◽  
Fausto Queda
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Fine Tuning ◽  
Reduced Form ◽  
Partial Hydrolysis ◽  
Reaction Conditions ◽  
Diels Alder Reaction ◽  
Direct Use ◽  
Kinetics Of ◽  
Hydrolysis Of

The Diels-Alder (DA) reaction of biomass derived furans is an emerging technology for the preparation of new molecular entities and “drop-in” commodity chemicals. In this work we address the challenge of the direct use of electron-poor furanic platforms as dienes through the use of an unexplored chitin derived furan, 3-acetamido-5-acetylfuran (3A5AF). The 3-acetamido group promoted a remarkable increase in the kinetics of the DA allowing for the preparation of 7-oxanorbornenes (7-ONB) at 50 ºC. Partial hydrolysis of the enamide to hemi-acylaminals was possible upon fine tuning of the reaction conditions, disabling retro-DA processes. Finally, DA reaction of the reduced form of 3A5AF allowed quantitative formation of 7-ONB in aqueous condition after 10 minutes. Certanly these are the first steps for expanding the toolbox of chitin derived 3A5AF as diene.

Pyrrole Chemistry. XV. The Chemistry of Some 3,4-Disubstituted Pyrroles

1973 ◽  
Vol 51 (7) ◽  
pp. 1089-1098 ◽  
Author(s):  
John Kington Groves ◽  
Niven Eddy Cundasawmy ◽  
Hugh John Anderson
Keyword(s):  
Raney Nickel ◽  
Aluminum Chloride ◽  
Alder Reaction ◽  
Subsequent Treatment ◽  
Diels Alder ◽  
Partial Hydrolysis ◽  
Antimitotic Agent ◽  
Proton Abstraction ◽  
Diels Alder Reaction ◽  
Hydrolysis Of

The syntheses of a variety of 3,4-disubstituted pyrroles including the antimitotic agent Verrucarin E are described. 3,4-Pyrroledicarboxylic esters were prepared through a Diels–Alder reaction. Partial hydrolysis of the diesters gave the 4-ester-3-acids which were modified to achieve the synthesis of a variety of unsymmetrically 3,4-disubstituted pyrroles. Raney nickel reduction of a thiolester gave hydroxymethyl under conditions which left acyl or carbalkoxy substituents unaffected. Pyrrole reactions involving carbanionic reagents are complicated by 1-proton abstraction. Therefore, when necessary, the nitrogen was protected by an N-benzyloxymethyl substituent which can be cleaved to the N-hydroxymethyl derivative by aluminum chloride or by hydrogenolysis. Subsequent treatment with benzyltrimethylammonium hydroxide gave back the pyrrole.

Kinetic Study of the Diels-Alder Reaction of Cyclopentadiene with Bis(2-Ethylhexyl) Maleate

2013 ◽  
Vol 634-638 ◽  
pp. 541-545 ◽  
Author(s):  
Jun Seong Park ◽  
Dae Hee Yun ◽  
Tae Won Ko ◽  
Yong Sung Park ◽  
Je Wan Woo
Keyword(s):  
Kinetic Study ◽  
Reaction Temperature ◽  
Atmospheric Pressure ◽  
Arrhenius Equation ◽  
Alder Reaction ◽  
Diels Alder ◽  
Influence Of Temperature ◽  
Diels Alder Reaction ◽  
Influence Of Temperature On ◽  
Kinetics Of

The kinetics of the Diels-Alder reaction of cyclopentadiene with bis(2-ethylhexyl) maleate has been studied at temperatures between 25 and 100 °C and at atmospheric pressure. The influence of temperature on the kinetic constants was determined by fitting the results to the Arrhenius equation. As a result, fitting line similar with the linear curve of the Arrhenius equation at 25, 30 and 40 °C. However, the fitting curve, at 60, 80 and 100 °C, tended towards the outside of the curve in the form of Arrhenius equation. The ratio of endo/exo was a slight change from increase of the reaction temperature.

A synthesis and some reactions of 7-Oxabicyclo[2.2.1]heptan-2-one

1983 ◽  
Vol 36 (12) ◽  
pp. 2473 ◽  
Author(s):  
J Moursounidis ◽  
D Wege
Keyword(s):  
Thermal Decomposition ◽  
Alder Reaction ◽  
Diels Alder ◽  
Acid Mixture ◽  
Diels Alder Reaction ◽  
Reaction Proceeds ◽  
Atom Migration ◽  
Acyl Azide ◽  
Mild Hydrolysis ◽  
Hydrolysis Of

Diels-Alder reaction between furan and α-chloroacrylonitrile gives a mixture of exo-2-chloro-and endo-2-chloro-7-oxabicyclo[2.2.1]hept-5-ene-2-carbonitrile (4) and (5). Mild hydrolysis affords the corresponding α-chloro acid mixture, from which the endo carboxylic acid may be removed through iodo lactone formation. Catalytic hydrogenation of (4) and (5) followed by hydrolysis, acyl azide formation, Curtius rearrangement, and hydrolysis of the resulting mixture of a-chloro isocyanates yields 7-oxabicyclo[2.2.l]heptan-2-one (1) in preparatively useful amounts. Reduction of (1) gives only endo alcohol, and Baeyer-Villiger reaction proceeds with exclusive bridgehead atom migration. Thermal decomposition of the sodium salt of the p-toluenesulfonylhydrazone of (1) affords 7-oxatricyclo[2.2.1 .02,6]heptane.

Single wall carbon nanotube (SWCNT)–gold nanorod (AuNR) conjugates via thermally-mild reaction conditions

2017 ◽  
Vol 41 (21) ◽  
pp. 12392-12396 ◽  
Author(s):  
Siting Ni ◽  
Jun Zhu ◽  
Mohamed Amine Mezour ◽  
R. Bruce Lennox
Keyword(s):  
Carbon Nanotube ◽  
Covalent Binding ◽  
Alder Reaction ◽  
Diels Alder ◽  
Gold Nanorod ◽  
Reaction Conditions ◽  
Single Wall Carbon ◽  
Inverse Electron Demand ◽  
Diels Alder Reaction ◽  
Electron Demand

A thermally-mild method for covalent binding of SWCNTs to AuNRs, based on an inverse-electron-demand Diels–Alder reaction, is established and discussed.

Reply to Comment on “Kinetics of a Diels−Alder Reaction of Maleic Anhydride and Isoprene in Supercritical CO2”

2003 ◽  
Vol 107 (43) ◽  
pp. 9249-9249 ◽  
Author(s):  
Evgeni M. Glebov ◽  
Larisa G. Krishtopa ◽  
Victor Stepanov ◽  
Lev N. Krasnoperov
Keyword(s):  
Maleic Anhydride ◽  
Supercritical Co2 ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Kinetics Of

Kinetics of a Diels—Alder Reaction in Supercritical Propane

1995 ◽  
pp. 166-178 ◽  
Author(s):  
Barbara L. Knutson ◽  
Angela K. Dillow ◽  
Charles L. Liotta ◽  
Charles A. Eckert
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Kinetics Of

scholarly journals Heterogeneous Intramolecular Electric Field as a Descriptor of Diels-Alder Reactivity

2020 ◽  
Author(s):  
Matthew Hennefarth ◽  
Anastassia N. Alexandrova
Keyword(s):  
Electric Field ◽  
Electron Density ◽  
Electric Fields ◽  
Alder Reaction ◽  
Diels Alder ◽  
Charge Movement ◽  
External Electric Fields ◽  
Topological Features ◽  
Diels Alder Reaction ◽  
Kinetics Of

<div> <div> <div> <p>External electric fields have proven to be an effective tool in catalysis, on par with pressure and temperature, affecting the thermodynamics and kinetics of a reaction. However, fields in molecules are complicated heterogeneous vector objects, and there is no universal recipe for grasping the exact features of these fields that implicate reactivity. Herein, we demonstrate that topological features of the heterogeneous electric field within the reactant state, as well as of the quantum mechanical electron density – a scalar reporter on the field experienced by the system – can be identified as rigorous descriptors of the reactivity to follow. We scrutinize specifically the Diels-Alder reaction. Its 3-D nature and the lack of a singular directionality of charge movement upon barrier crossing makes the effect of the electric field not obvious. We show that the electric field topology around the dienophile double bond, and the associated changes in the topology of the electron density in this bond are predictors of the reaction barrier. They are also the metrics by which to rationalize and predict how the external field would inhibit or enhance the reaction. The findings pave the way toward designing external fields for catalysis, as well as reading the reactivity without an explicit mechanistic interrogation, for a variety of reactions. </p> </div> </div> </div>

COS-triggered Oxygen/Sulfur Exchange of Isatins: Chemoselective Synthesis of Functionalized Isoindigos and Spirothiopyrans via Self-condensation and Thio-Diels-Alder Reaction

2022 ◽  
Author(s):  
Wei Chen ◽  
Hui Zhou ◽  
Bai-Hao Ren ◽  
Wei-Min Ren ◽  
Xiaobing Lu
Keyword(s):  
Exchange Reaction ◽  
Sulfur Atom ◽  
Carbonyl Sulfide ◽  
Alder Reaction ◽  
Diels Alder ◽  
Reaction Conditions ◽  
Diels Alder Reaction ◽  
Chemoselective Synthesis ◽  
Sulfur Exchange

Herein, we present the first organocatalytic oxygen/sulfur atom exchange reaction (O/S ER) of isatins by employing carbonyl sulfide (COS) as novel sulfuring reagent under mild reaction conditions. 8-Diazabicyclo[5.4.0] undec-7-ene (DBU),...

scholarly journals Asymmetric Brønsted acid-catalyzed aza-Diels–Alder reaction of cyclic C-acylimines with cyclopentadiene

2012 ◽  
Vol 8 ◽  
pp. 1819-1824 ◽  
Author(s):  
Magnus Rueping ◽  
Sadiya Raja
Keyword(s):  
Alder Reaction ◽  
Optically Active ◽  
Diels Alder ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Reaction Conditions ◽  
Diels Alder Reaction ◽  
Brönsted Acid ◽  
Acid Catalyzed ◽  
Chiral Bronsted Acid

A new chiral Brønsted acid-catalyzed aza-Diels–Alder reaction of cyclic C-acylimines with cyclopentadiene has been developed. The reaction provides optically active aza-tetracycles in good yields with high diastereo- and enantioselectivities under mild reaction conditions.

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