Hydrophobilization of Furan-Containing Polyurethanes via Diels–Alder Reaction with Fatty Maleimides

We describe new hydrophobic functionalized linear polyurethane resins by combining N-alkyl maleimides via the Diels–Alder reaction with linear furan-modified polyurethanes. This procedure provides the opportunity for the post-polymerization-functionalizing of polyurethanes. Access to furan-bearing polyurethanes is achieved via the reaction of a furan-containing diol, polyethylenglycol (PEG), and different diisocyanates. The furan-containing diol is obtained from the reaction of furfurylamine and two equivalents of hydroxyalkyl acrylate. The resulting furan-bearing polyurethanes are reacted with fatty amine-based N-alkyl maleimides. The maleimide and furan functionalities undergo a Diels–Alder reaction, which allows for the covalent bonding of the hydrophobic side chains to the polyurethane backbone. The covalent bonding of the hydrophobic maleimides to the polyurethane backbone is proven by means of NMR. The influence of the functionalization on the surface properties of the resulting polyurethane films is analyzed via the determination of surface energy via the sessile drop method.

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Secondary orbital interactions determining regioselectivity in the Diels-Alder reaction. 4. Experimental and theoretical examination of the reaction of acrylonitrile with 1-(phenylthio)-2-methoxy-1,3-butadiene. Determination of the conformations of the four cyclohexene adducts by proton NMR

The Journal of Organic Chemistry ◽

10.1021/jo00415a015 ◽

1978 ◽

Vol 43 (21) ◽

pp. 4052-4057 ◽

Cited By ~ 22

Author(s):

Theodore Cohen ◽

Robert J. Ruffner ◽

David W. Shull ◽

Wlodzimierz M. Daniewski ◽

Raphael M. Ottenbrite ◽

...

Keyword(s):

Proton Nmr ◽

Alder Reaction ◽

Diels Alder ◽

Orbital Interactions ◽

Theoretical Examination ◽

Diels Alder Reaction

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The RHF– and UHF–AM1 potential-energy surfaces for the diels–alder reaction of substituted butadienes with substituted ethenes. Part 58.—Determination of reactivity by MO theory

Journal of the Chemical Society Faraday Transactions 2 Molecular and Chemical Physics ◽

10.1039/f29898500867 ◽

1989 ◽

Vol 85 (7) ◽

pp. 867-877 ◽

Cited By ~ 8

Author(s):

Jae Young Choi ◽

Ikchoon Lee

Keyword(s):

Potential Energy ◽

Potential Energy Surfaces ◽

Alder Reaction ◽

Diels Alder ◽

Diels Alder Reaction ◽

Energy Surfaces ◽

Mo Theory

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Experimental Determination of the Absolute Enantioselectivity of an Antibody-Catalyzed Diels−Alder Reaction and Theoretical Explorations of the Origins of Stereoselectivity

Journal of the American Chemical Society ◽

10.1021/ja020879d ◽

2003 ◽

Vol 125 (9) ◽

pp. 2489-2506 ◽

Cited By ~ 40

Author(s):

Carina E. Cannizzaro ◽

Jon A. Ashley ◽

K. D. Janda ◽

K. N. Houk

Keyword(s):

Experimental Determination ◽

Alder Reaction ◽

Diels Alder ◽

Diels Alder Reaction ◽

The Absolute

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ChemInform Abstract: Substituted 1-Thia-3-aza-1,3-butadiene: Diels-Alder Reaction with Methyl Acrylate. Determination of Activation Parameters.

ChemInform ◽

10.1002/chin.198946215 ◽

1989 ◽

Vol 20 (46) ◽

Author(s):

M. CHEHNA ◽

J. P. PRADERE ◽

H. QUINIOU ◽

D. LE BOTLAN ◽

L. TOUPET

Keyword(s):

Methyl Acrylate ◽

Activation Parameters ◽

Alder Reaction ◽

Diels Alder ◽

Diels Alder Reaction ◽

Substituted 1

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A Computational Study of the Relative Aromaticity of Pyrrole, Furan, Thiophene and Selenophene, and Their Diels-Alder Stereoselectivity

10.26434/chemrxiv.12734039.v1 ◽

2020 ◽

Author(s):

Veejendra Yadav

Keyword(s):

Computational Study ◽

Lone Pair ◽

Alder Reaction ◽

Diels Alder ◽

Size Mismatch ◽

Aromatic Character ◽

Diels Alder Reaction ◽

Ground State Structures ◽

Better Than

The collinearity of terminal p orbitals of a diene with that of a dienophile is required for an effective overlap to result in s bond formation during the Diels-Alder reaction. The ease of the DA reaction of a cyclic diene with a given dienophile, therefore, must also depend on the distance between the termini of the diene. A distance larger than the unsaturated bond of the dienophile is expected to raise the energy of activation. This scenario has been amply demonstrated from the study of reactions of several dienes, some designed to serve the purpose, with different dienophiles. The five-ring heterocycles pyrrole, furan, thiophene and selenophene possess varying aromatic character for the varied resonance participation of the heteroatom lone pair with ring p bonds. The aromaticity decreases in the same order due to: (a) the increasing sC-X (X = heteroatom) bond length lifts the bond uniformity required for ring current, hence aromaticity, such as in benzene and (b) size-mismatch of the interacting lone pair orbital and the ring p orbitals, especially in thiophene and selenophene, both allowing poor overlap in the ground state structures. It is demonstrated that increase alone in the activation energies of the DA reactions of pyrrole, furan, thiophene and selenophene cannot be considered a measure of relative aromaticity as often done and even theoretically attempted in many ways to prove just that. The separation of the termini of the diene has a much larger role in the determination of activation energy, especially in thiophene and selenophene, than their aromaticity profile. There cannot be a measure better than the relative intensity of heteroatom lone pair overlap with ring p bonds, giving rise to a six-electron like system in following Hückel’s 4n+2 rule, to assess the relative aromaticity.

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