Site-selectivity control in hetero-Diels–Alder reactions of methylidene derivatives of lawsone through modification of the reactive carbonyl group: an experimental and theoretical study

2019 ◽  
Vol 17 (3) ◽  
pp. 692-702 ◽  
Author(s):  
Maria Tsanakopoulou ◽  
Erifili Tsovaltzi ◽  
Marina A. Tzani ◽  
Periklis Selevos ◽  
Elizabeth Malamidou-Xenikaki ◽  
...  
Keyword(s):  
Carbonyl Group ◽  
Theoretical Study ◽  
Diels Alder ◽  
Site Selectivity ◽  
Selectivity Control ◽  
Derivatives Of ◽  
Reactive Carbonyl

Selective monoacetalization of lawsone inverts the site-selectivity of the Diels–Alder reactions of its alkylidene derivatives favoring the protected β-lapachone derivatives.

Theoretical study of diels-alder reactions between substituted derivatives of butadiene and ethylene

Tetrahedron ◽  
1978 ◽  
Vol 34 (13) ◽  
pp. 2029-2033 ◽  
Author(s):  
A. Oliva ◽  
J.I. Fernández-Alonso ◽  
J. Bertrán
Keyword(s):  
Theoretical Study ◽  
Diels Alder ◽  
Derivatives Of

Mechanism and site selectivity in the Diels-Alder reaction between protoanemonin and butadiene. A theoretical study

1991 ◽  
Vol 56 (6) ◽  
pp. 2190-2193 ◽  
Author(s):  
Vicenc Branchadell ◽  
Juan Orti ◽  
Rosa Maria Ortuno ◽  
Antonio Oliva ◽  
Josep Font ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Site Selectivity

scholarly journals Selectivity control in hydrogenation through adaptive catalysis using ruthenium nanoparticles on a CO2-responsive support

2021 ◽  
Author(s):  
Alexis Bordet ◽  
Sami El Sayed ◽  
Matthew Sanger ◽  
Kyle J. Boniface ◽  
Deepti Kalsi ◽  
...  
Keyword(s):  
Real Time ◽  
Carbonyl Group ◽  
Catalytic Reaction ◽  
Renewable Resources ◽  
Gas Composition ◽  
Ruthenium Nanoparticles ◽  
Catalytic Systems ◽  
Amine Functionalized ◽  
Hydrogenation Reactions ◽  
Selectivity Control

AbstractWith the advent of renewable carbon resources, multifunctional catalysts are becoming essential to hydrogenate selectively biomass-derived substrates and intermediates. However, the development of adaptive catalytic systems, that is, with reversibly adjustable reactivity, able to cope with the intermittence of renewable resources remains a challenge. Here, we report the preparation of a catalytic system designed to respond adaptively to feed gas composition in hydrogenation reactions. Ruthenium nanoparticles immobilized on amine-functionalized polymer-grafted silica act as active and stable catalysts for the hydrogenation of biomass-derived furfural acetone and related substrates. Hydrogenation of the carbonyl group is selectively switched on or off if pure H2 or a H2/CO2 mixture is used, respectively. The formation of alkylammonium formate species by the catalytic reaction of CO2 and H2 at the amine-functionalized support has been identified as the most likely molecular trigger for the selectivity switch. As this reaction is fully reversible, the catalyst performance responds almost in real time to the feed gas composition.

scholarly journals Fates of imine intermediates in radical cyclizations of N-sulfonylindoles and ene-sulfonamides

2015 ◽  
Vol 11 ◽  
pp. 1649-1655 ◽  
Author(s):  
Hanmo Zhang ◽  
E Ben Hay ◽  
Stephen J Geib ◽  
Dennis P Curran
Keyword(s):  
Carbonyl Group ◽  
Ring Opening ◽  
Radical Cyclizations ◽  
Type Reaction ◽  
Primary Products ◽  
Lactam Carbonyl Group ◽  
Lactam Carbonyl ◽  
Imine Reduction ◽  
Derivatives Of

Two new fates of imine intermediates formed on radical cyclizations of ene-sulfonamides have been identified, reduction and hydration/fragmentation. Tin hydride-mediated cyclizations of 2-halo-N-(3-methyl-N-sulfonylindole)anilines provide spiro[indoline-3,3'-indolones] or spiro-3,3'-biindolines (derived from imine reduction), depending on the indole C2 substituent. Cyclizations of 2-haloanilide derivatives of 3-carboxy-N-sulfonyl-2,3-dihydropyrroles also presumably form spiro-imines as primary products. However, the lactam carbonyl group facilitates the ring-opening of these cyclic imines by a new pathway of hydration and retro-Claisen-type reaction, providing rearranged 2-(2'-formamidoethyl)oxindoles.

Diels–Alder reactions of pinacol alkenylboronates: an experimental and theoretical study

RSC Advances ◽  
2014 ◽  
Vol 4 (68) ◽  
pp. 36385-36400 ◽  
Author(s):  
Margarita M. Vallejos ◽  
Nicolás Grimblat ◽  
Silvina C. Pellegrinet
Keyword(s):  
Theoretical Study ◽  
Diels Alder ◽  
Pressure Tube ◽  
Thermal Heating

We have studied the Diels–Alder reactions of pinacol alkenylboronates with cyclopentadiene under two different sets of conditions: thermal heating at 170 °C in a pressure tube and with catalytic TFA (5 mol%) at 80 °C.

scholarly journals Photofading of Derivatives of Paraben (PHB) by AM1 and PM3 Methods: A Theoretical Study

2019 ◽  
Vol 07 (02) ◽  
pp. 39-50
Author(s):  
Krzysztof Wojciechowski ◽  
Lucjan Szuster
Keyword(s):  
Theoretical Study ◽  
Derivatives Of

Reaktionsverhalten von β-Oxo-carbonsäurederivaten der Anthracenreihe bei der Synthese von Pyrazolen / On the Reaction Behavior of ß-Oxo Carbonic Acid Derivatives of the Anthracene Series in Pyrazole Synthesis

1999 ◽  
Vol 54 (9) ◽  
pp. 1133-1137
Author(s):  
Astrid Knieß ◽  
Margit Gruner ◽  
Roland Mayer
Keyword(s):  
Carbonyl Group ◽  
Carbonic Acid ◽  
Ester Group ◽  
Reaction Behavior ◽  
Anthracene Derivatives ◽  
Sterical Hindrance ◽  
Derivatives Of

ß-Oxo-1 and 9-anthracenepropionate (6 and 7) reacts with DMF-acetale to enaminones 10 and 11. The reaction of 2-(dimethylamino)methylen-substituted ß-oxo-1 -anthracenepropionate (10) with hydrazines yields 5-(l-anthracenyl)-pyrazol-4-carboxylates (13). In contrast, the cyclocondensation of 3-(9-anthracenyl)-2-(dimethylamino)methylen-3-oxo-propionate (11) with hydrazine hydrochlorides gives 4-(9-anthracenoyl)-5-hydroxy-pyrazoles (14). This is caused by the sterical hindrance of the carbonyl group of the anthracene derivatives in position 9; thus, the cyclocondensation proceeds via reaction of the ester group of the enaminone 11.

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