69485-50-3Relevant academic research and scientific papers
Metal-free ring-opening metathesis polymerization
Ogawa, Kelli A.,Goetz, Adam E.,Boydston, Andrew J.
, p. 1400 - 1403 (2015)
We have developed a method to achieve ring-opening metathesis polymerization (ROMP) mediated by oxidation of organic initiators in the absence of any transition metals. Radical cations, generated via one-electron oxidation of vinyl ethers, were found to react with norbornene to give polymeric species with microstructures essentially identical to those traditionally obtained via metal-mediated ROMP. We found that vinyl ether oxidation could be accomplished under mild conditions using an organic photoredox mediator. This led to high yields of polymer and generally good correlation between Mn values and initial monomer to catalyst loadings. Moreover, temporal control over reinitiation of polymer growth was achieved during on/off cycles of light exposure. This method demonstrates the first metal-free method for controlled ROMP.
Borata-Wittig olefination reactions of ketones, carboxylic esters and amides with bis(pentafluorophenyl)borata-alkene reagents
Wang, Tongdao,Kohrt, Sonja,Daniliuc, Constantin G.,Kehr, Gerald,Erker, Gerhard
supporting information, p. 6223 - 6232 (2017/08/02)
The strongly electrophilic borane derivative amino-CH2CH2CH2-B(C6F5)26 was α-CH deprotonated with LiTMP to give the borata-alkene {[amino-(CH2)2-CHB(C6F5)2-][Li+]}29 which underwent facile [2 + 2] cycloaddition reactions with benzophenone or fluorenone to yield the respective 1,2-oxaboretanides 11a,b. Compounds 9 and 11 were characterized by the X-ray diffraction. Thermolysis or hydrolysis of compounds 11a,b gave the corresponding borata-Wittig olefination products 12a,b. A variety of R-CH2-CH2-B(C6F5)2 boranes (conveniently generated by hydroboration of terminal alkenes R-CHCH2 with Piers' borane [HB(C6F5)2]) were analogously deprotonated to give the respective borata-alkenes 16a-e (R: Ph-CH2-, nC4H9, tBu, Cy, PhCH2CH2-). They underwent "non-classical" borata-Wittig olefination reactions with ethylformate to give the respective enolether carbonylation products, or their C1-elongated aldehydes (after hydrolysis). The borata-alkene [Ph-(CH2)2-CHB(C6F5)2-] [Li+HTMP] (16a) gave the respective "non-classical" borata-Wittig olefination products, the enolethers 25a,b and 27, respectively, upon treatment with methyl- or ethyl acetate or γ-butyrolactone.
METATHESIS POLYMERIZATION METHODS
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Page/Page column 41-42, (2016/05/02)
The present disclosure is directed to methods of making a polymer, including exposing a reaction mixture including a strained cyclic unsaturated monomer and an organic initiator to a stimulus to provide an activated organic initiator, whereby the activate
