Fast & easy preparation of 3D scaffolds from methyl benzoate by a diversity oriented synthesis strategy based on Diels–Alder and ene-reactions

2017 ◽  
Vol 15 (26) ◽  
pp. 5585-5592
Author(s):  
Dominique Brossard ◽  
Pascal Retailleau ◽  
Vincent Dumontet ◽  
Philippe Breton ◽  
Sandy Desrat ◽  
...  
Keyword(s):  
Diels Alder ◽  
Methyl Benzoate ◽  
3D Scaffolds ◽  
Ene Reactions ◽  
Diversity Oriented Synthesis ◽  
Ene Reaction ◽  
3D Shape ◽  
Synthesis Strategy

Thermic dimerization of methyl 1,3-cyclohexadiene 2-carboxylate gave original 3D-shape compounds by Diels–Alder cycloaddition and original [6 + 4]-ene reaction.

scholarly journals Zur Reaktivität des Germaethens Me2Ge=C(SiMe3)2: Mechanistische Aspekte der Diels-Aider- und En-Reaktionen [1] / On the Reactivity of Germaethene Me2Ge=C (SiMe3)2: Mechanistic Aspects of Diels Alder and Ene Reactions [1]

1996 ◽  
Vol 51 (6) ◽  
pp. 838-850 ◽  
Author(s):  
Nils Wiberg ◽  
Susanne Wagner
Keyword(s):  
Double Bond ◽  
Energy Difference ◽  
Diels Alder ◽  
Bond Polarity ◽  
Ene Reactions ◽  
Ene Reaction

Abstract Diels-Alder and ene reactions of germaethene Me2Ge=C(SiMe3)2 (2) with butadienes respectively, take place regioselectively, as well as stereoselectively. They are accelerated by an increasing tendency of substituents in butadiene or propene to donate electrons (e.g. 2-methylbutadiene > butadiene; 2-methylpropene > propene), and retarded by an increasing bulkyness of substituents in 1,4- or 1,3-positions (e.g. 1-methylbutadiene > 2-methylbutadiene; 1-vinylpropene > propene). It is concluded from these studies that Diels-Alder and ene reactions of 2 occur - like those of Me2Si=C(SiMe3)2 (1) or of ethenes >C=C< - in a concerted way and are HOMOdiene-LUMOdienophile and HOMOene-LUMOenophile controlled. Thus 2 and 1 behave as carbon analogues. With regard to a specific diene or ene (e.g. anthracene; toluene), 2 is the better dienophile or enophile than 1 or ethenes. With a fixed diene/ene mixture (e.g. butadiene/propene), 2 acts as the better dienophile, while 1 is the better enophile. These results can be explained by the π/π*- energy difference and the double bond polarity decreasing in the direction 1 > 2. Only cis-piperylene gives a [2+2] cycloadduct with 2. besides two [4+2] cycloadducts, and an ene reaction product

scholarly journals Rheometer Evidences for the Co-Curing Effect of a Bismaleimide in Conjunction with the Accelerated Sulfur on Natural Rubber/Chloroprene Rubber Blends

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1510
Author(s):  
Marek Pöschl ◽  
Shibulal Gopi Sathi ◽  
Radek Stoček ◽  
Ondřej Kratina
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Tensile Properties ◽  
Crosslinking Agent ◽  
Alder Reaction ◽  
Diels Alder ◽  
Ene Reactions ◽  
Rubber Blends ◽  
Diels Alder Reaction ◽  
Chloroprene Rubber

The rheometer curing curves of neat natural rubber (NR) and neat chloroprene rubber (CR) with maleide F (MF) exhibit considerable crosslinking torque at 180 °C. This indicates that MF can crosslink both these rubbers via Alder-ene reactions. Based on this knowledge, MF has been introduced as a co-crosslinking agent for a 50/50 blend of NR and CR in conjunction with accelerated sulfur. The delta (Δ) torque obtained from the curing curves of a blend with the addition of 1 phr MF was around 62% higher than those without MF. As the content of MF increased to 3 phr, the Δ torque was further raised to 236%. Moreover, the mechanical properties, particularly the tensile strength of the blend with the addition of 1 phr MF in conjunction with the accelerated sulfur, was around 201% higher than the blend without MF. The overall tensile properties of the blends cured with MF were almost retained even after ageing the samples at 70 °C for 72 h. This significant improvement in the curing torque and the tensile properties of the blends indicates that MF can co-crosslink between NR and CR via the Diels–Alder reaction.

ChemInform Abstract: Formal [2 + 2 + 2] Cycloaddition Strategy Based on an Intramolecular Propargylic Ene Reaction/Diels-Alder Cycloaddition Cascade.

ChemInform ◽  
2010 ◽  
Vol 42 (1) ◽  
pp. no-no
Author(s):  
Julia M. Robinson ◽  
Takeo Sakai ◽  
Katsuhiko Okano ◽  
Takafumi Kitawaki ◽  
Rick L. Danheiser
Keyword(s):  
Diels Alder ◽  
Ene Reaction

ChemInform Abstract: Tandem Diels-Alder and Retro-Ene Reactions of 1-Sulfenyl- and 1-Sulfonyl-1,3-dienes as a Traceless Route to Cyclohexenes.

ChemInform ◽  
2015 ◽  
Vol 46 (7) ◽  
pp. no-no
Author(s):  
Jin Choi ◽  
Hoyoon Park ◽  
Hyun Jung Yoo ◽  
Sinae Kim ◽  
Erik J. Sorensen ◽  
...  
Keyword(s):  
Diels Alder ◽  
Ene Reactions

Nitrosocarbonyl Carbohydrate Derivatives: Hetero Diels–Alder and Ene Reaction Products for Useful Organic Synthesis

Synthesis ◽  
2020 ◽  
Author(s):  
Paolo Quadrelli ◽  
Marco Corti ◽  
Marco Leusciatti ◽  
Mattia Moiola ◽  
Mariella Mella
Keyword(s):  
Organic Synthesis ◽  
Tertiary Amine ◽  
Diels Alder ◽  
Mild Oxidation ◽  
Reaction Products ◽  
Ene Reaction ◽  
Nitrile Oxides

AbstractThe generation and trapping of two new nitrosocarbonyl intermediates bearing carbohydrate-based chiral substituents is achieved by the mild oxidation of the corresponding nitrile oxides with tertiary amine N-oxides. Their capture with suitable dienes and alkenes afforded the corresponding hetero Diels–Alder cycloadducts and ene adducts from fair to excellent yields. The entire methodology looks highly promising by the easy conversion of aldoximes into hydroxymoyl halides, widening the access to nitrosocarbonyls, versatile tools in organic synthesis.

Reactions of Dimethyl (2'-Oxopropylidene)Propanedioate and Dimethyl (3'-Bromo-2'-oxopropylidene)propanedioate, Two Highly Electrophilic Trisubstituted Alkenes

1987 ◽  
Vol 40 (11) ◽  
pp. 1831 ◽  
Author(s):  
DW Cameron ◽  
RW Read ◽  
J Stavrakis
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Low Molecular Weight ◽  
Ene Reaction ◽  
Inverse Electron Demand ◽  
Diels Alder Reaction ◽  
Alkaline Conditions ◽  
Nucleophilic Reagents ◽  
Trisubstituted Alkenes ◽  
Electron Demand

The keto diester, dimethyl (2'-oxopropylidene)propanedioate, and its new 3'-bromo derivative have been made to react with a variety of nucleophilic reagents. Low molecular weight products have been obtained efficiently by processes involving conjugate addition, Diels-Alder reaction, Diels-Alder reaction having inverse electron demand, or ene reaction. Regiochemistry of the reactions is controlled by the dominant withdrawing effect of the two geminal ester groups. The amine addition products of the bromo keto diester were found to undergo a novel secondary dehydrobromination reaction under alkaline conditions.

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