5363-64-4Relevant academic research and scientific papers
Alternating copolymerization by nitroxide-mediated polymerization and subsequent orthogonal functionalization
Tesch, Matthias,Hepperle, Johannes A. M.,Klaasen, Henning,Letzel, Matthias,Studer, Armido
, p. 5054 - 5059 (2015)
A novel method for the preparation of functionalized alternating copolymers is presented. Nitroxide-mediated polymerization of hexafluoroisopropyl acrylate with 7-octenyl vinyl ether provides the corresponding alternating polymer, which can be chemically modified using two orthogonal polymer-analogous reactions. A thiol-ene click reaction followed by amidation provides dual-functionalized alternating copolymers. The potential of this method is illustrated by the preparation of a small library (15 examples) of functionalized alternating copolymers. Alternating through double click: The title reaction of A with hexafluoroisopropyl acrylate (HFIPA) provides alternating polymer B, which can be chemically modified using two orthogonal polymer-analogous reactions. With this method, a small library of fifteen functionalized alternating copolymers was prepared.
Enol Ethers Are Effective Monomers for Ring-Opening Metathesis Polymerization: Synthesis of Degradable and Depolymerizable Poly(2,3-dihydrofuran)
Feist, John D.,Xia, Yan
supporting information, p. 1186 - 1189 (2020/02/04)
Enol ethers are widely used as quenching reagents for Grubbs catalysts. However, we report the surprisingly effective ring-opening metathesis polymerization (ROMP) of cyclic enol ethers, because the resulting electron-rich ruthenium alkylidene complex remains active toward metathesis of electron-rich olefins, despite its deactivation toward hydrocarbon olefins. We demonstrate the first example of ROMP of cyclic enol ethers, using 2,3-dihydrofuran as the monomer, producing a new type of degradable and depolymerizable poly(enol ether). The polymers exhibited perfect regioregularity, and their molecular weights can be regulated by the loading of Grubbs initiators or by the use of a linear vinyl ether as the chain transfer agent. We also developed protocols to deactivate the catalyst following metathesis of enol ethers and cleave the catalyst off the resulting polymers using H2O2 oxidation. The resulting poly(dihydrofuran) can be recycled to monomer via depolymerization with Grubbs catalyst or degraded to small molecules by hydrolysis under acidic conditions. This work opens exciting opportunities for a new class of ROMP monomers that lead to degradable polymers.
A solid acetylene reagent with enhanced reactivity: Fluoride-mediated functionalization of alcohols and phenols
Werner, Georg,Rodygin, Konstantin S.,Kostin, Anton A.,Gordeev, Evgeniy G.,Kashin, Alexey S.,Ananikov, Valentine P.
supporting information, p. 3032 - 3041 (2017/07/24)
The direct vinylation of an OH group in alcohols and phenols was carried out utilizing a novel CaC2/KF solid acetylene reagent in a simple K2CO3/KOH/DMSO system. The functionalization of a series of hydroxyl-group-containing substrates and the post-modification of biologically active molecules were successfully performed using standard laboratory equipment, providing straightforward access to the corresponding vinyl ethers. The overall process developed involves an atom-economical addition reaction employing only inorganic reagents, which significantly simplifies the reaction set-up and the isolation of products. A mechanistic study revealed a dual role of the F- additive, which both mediates the surface etching/renewal of the calcium carbide particles and activates the CC bond towards the addition reaction. The development of the fluoride-mediated nucleophilic addition of alcohols eliminates the need for strong bases and may substantially extend the areas of application of this attractive synthetic methodology due to increasing functional group tolerance. As a replacement for dangerous and difficult to handle high-pressure acetylene, we propose the solid reagent CaC2/KF, which is easy to handle, does not require dedicated laboratory equipment and demonstrates enhanced reactivity of the acetylenic triple bond. Theoretical calculations have shown that fluoride-mediated activation of the hydroxyl group towards nucleophilic addition significantly reduces the activation barrier and facilitates the reaction.
METHOD OF PRODUCING VINYL ETHER, AND CATALYST FOR ETHER EXCHANGE REACTION
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Paragraph 0138, (2017/08/14)
PROBLEM TO BE SOLVED: To provide a method for producing vinyl ether that allows a reaction to sufficiently proceed even in a small amount of catalyst, and facilitates the recovery and reuse of the catalyst with excellent operability. SOLUTION: A method for producing vinyl ether represented by formula (3) is characterized in that alcohol and vinyl ether represented by formula (2) are subjected to ether replacement reaction. There is also provided catalyst that comprises a metal nano cluster obtained by heating a transition metal compound in solvent comprising coordination organic solvent and a nitrogen-containing heterocyclic compound. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
Reactivity of vinyl ethers and vinyl ribosides in UV-initiated free radical copolymerization with acceptor monomers
Pichavant, Loic,Guillermain, Ce Line,Coqueret, Xavier
scheme or table, p. 2415 - 2421 (2012/10/18)
The reactivity of various vinyl ethers and vinyloxy derivatives of ribose in the presence of diethyl fumarate or diethyl maleate was investigated for evaluating the potential of donor-acceptor-type copolymerization applied to unsaturated monomers derived from renewable feedstock. The photochemically induced polymerization of model monomer blends in the bulk state was monitored by infrared spectroscopy. The method allowed us to examine the influence of monomer pair structure on the kinetic profiles. The simultaneous consumption of both monomers was observed, supporting an alternating copolymerization mechanism. A lower reactivity of the blends containing maleates compared with fumarates was confirmed. The obtained kinetic data revealed a general correlation between the initial polymerization rate and the Hansen parameter aeH associated with the H-bonding aptitude of the donor monomer.
Fragrance precursors
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, (2008/06/13)
The present invention is a fragrance precursor of formula I: 1for a fragrant ketone of formula II: 2and a fragrant ester of formula III: 3wherein, R1 to R5 represent independently H, —NO2, linear or branched C1-C6-alkyl, C1-C6-alkenyl, C1-C6-alkinyl or C1-C4-alkoxy, R1 and R2, R2 and R3, R3 and R4, and R4 and R5 may form together one or two aliphatic or aromatic rings, R6 and R7 are independently H, linear or branched C1-C6-alkyl-, C1-C6-alkenyl, C1-C6-alkinyl, and R8 and R9 are the residues of an acid R8-COOH and an alcohol R9OH respectively forming the fragrant ester of formula III. A method for providing an odor by admixing with a product a fragrance precursor as detailed above.
