نتایج جستجو برای: Diels-Alder reaction

تعداد نتایج: 415019  

ژورنال: مواد پرانرژی 2016

The reversibility of the Diels-Alder reaction can be used advantageously in polyurethane materials to endow them with recyclable, thermally reversible properties and self-healing ability to expand their application range. In this paper, linear and crosslink polyurethanes based on HTPB, which exhibit thermal reversibility through Diels-Alder and retro Diels-Alder reactions, were prepared and cha...

2,4,6-Triisopropylstryrene was synthesized in a single step via the Witting Reaction from the corresponding aldehyde. The reaction of three styrene's derivatives, 2,6-dimethylstyrene, 2,4,6-trimethylstyrene, and 2,4,6- triisopropylstyrene with 4-methyl-l,2,4-triazoline-3,5-dion(M eTD) was investigated. These reactions are instantaneous at room temperature and lead to the formation of 2: 1 ...

Journal: :Angewandte Chemie 2003
Emily M Stocking Robert M Williams

Nature's repertoire of biosynthetic transformations has recently been recognized to include the Diels-Alder cycloaddition reaction. Evidence now exists that there are enzymes that mediate the Diels-Alder reaction in secondary metabolic biosynthetic pathways. 2002 marked the 100th anniversary of Alder's birth and 75 years since the discovery of the Diels-Alder reaction. It would appear that livi...

Journal: :journal of sciences islamic republic of iran 0

2,4,6-triisopropylstryrene was synthesized in a single step via the witting reaction from the corresponding aldehyde. the reaction of three styrene's derivatives, 2,6-dimethylstyrene, 2,4,6-trimethylstyrene, and 2,4,6- triisopropylstyrene with 4-methyl-l,2,4-triazoline-3,5-dion(m etd) was investigated. these reactions are instantaneous at room temperature and lead to the formation of 2: 1 ...

Journal: :Journal of the American Chemical Society 2004
Ellen S Gawalt Milan Mrksich

This paper describes the use of a substituent effects study to understand the mechanistic basis for an interfacial Diels-Alder reaction that does not proceed with standard second-order kinetics. Cyclopentadiene (Cp) undergoes a Diels-Alder reaction with a chemisorbed mercaptobenzoquinone to yield an immobilized Diels-Alder adduct. The pseudo-first-order rate constants are not linearly related t...

Journal: :Molecules 2007
Kyle E Litz

The aqueous Diels-Alder reaction of 1,3-cyclohexadiene with 1,4-benzoquinone was compared and contrasted to the same reaction catalyzed with Flextyl P, a novel Ti(IV) performance catalyst. The catalyst improved conversion by 22% versus the uncatalyzed reaction and represents a rare example of a Ti(IV) catalyzed Diels-Alder reaction in water.

2013
Radomir Jasiński Magdalena Kwiatkowska Valentin Sharnin Andrzej Barański

ABSTRACT The Diels-Alder reaction between methyl (Z)-2-nitro-3-(4-nitrophenyl)-2-propenoate and cyclopentadiene yields a mixture of carbodiene Diels-Alder adducts. B3LYP/6-31G(d) simulations indicate that the conversion of addends into methyl (1R*,2S*,3S*,4R*)-2-nitro-3-(4-nitrophenyl)-bicyclo[2.2.1]hept-5-ene-2-carboxylate occurs via two-stage heterodiene Diels-Alder reaction and (in a second ...

Journal: :Organic & biomolecular chemistry 2016
Inga Loke Guillaume Bentzinger Julia Holz Aruna Raja Aman Bhasin Florenz Sasse Andreas Köhn Rainer Schobert Sabine Laschat

In order to construct the functionalized AB ring system of clifednamide, member of the class of macrocyclic tetramic acid lactams, a synthesis was developed which utilized an Ireland-Claisen rearrangement and an intramolecular Diels-Alder reaction. Starting from di-O-isopropylidene-d-mannitol the allyl carboxylate precursor for the sigmatropic rearrangement was prepared. This rearrangement proc...

Journal: :Molecules 2014
Justyna M Zurek Robert L Rae Martin J Paterson Magnus W P Bebbington

Detailed analysis of calculated data from an experimental/computational study of intramolecular furan Diels-Alder reactions has led to the unusual discovery that the mean contraction of the newly forming C-C σ-bonds from the transition state to the product shows a linear correlation with both reaction Gibbs free energies and reverse energy barriers. There is evidence for a similar correlation i...

Journal: :Synthesis 2021

Abstract The Diels–Alder reaction has long been established as an extremely useful procedure in the toolbox of natural product chemists. It tolerates a wide spectrum building blocks different complexity and degrees derivatization, enables formation six-membered rings with well-defined stereochemistry. In recent years, many total syntheses products have reported that rely, at some point, on use ...

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