Access to Hydroxy‐Functionalized Polypropylene through Coordination Polymerization
作者:Yuanhao Zhong、Iskander Douair、Tiantian Wang、Chunji Wu、Laurent Maron、Dongmei Cui
DOI:10.1002/anie.201914747
日期:2020.3.16
polypropylene has proven a rather challenging goal in polymer science. Propylene can't be polymerized through a radical mechanism, and its coordination copolymerization with polar monomers is frustrated by catalyst poisoning. Herein, we report a new strategy to reach this target. The coordinationpolymerization of allenes by rare-earth-metalprecursors affords pure 1,2-regulated polyallenes, which are
作者:Ursula Streit、Frédéric Birbaum、Anna Quattropani、Christian G. Bochet
DOI:10.1021/jo4002307
日期:2013.7.19
report on a new intramolecular para cycloaddition of arenes with allenes, yielding attractive rigid scaffolds bearing several reactive functionalities to build in further diversity. Bicyclo[2.2.2]octadiene-type products and benzoxepine acetals are formed in this reaction, in ratios and yields depending on the substitution pattern on the aromatic ring, the nature of the chromophore, and the tether. This unprecedented
Synthesis of allenes via CuBr-catalyzed homologation of alk-1-ynes accelerated by microwave
作者:Hiroyuki Nakamura、Tsuyuka Sugiishi、Yuko Tanaka
DOI:10.1016/j.tetlet.2008.10.019
日期:2008.12
CuBr-catalyzed homologation of alk-1-ynes 1 with paraformaldehyde and N,N-diisopropylamine (or N,N-dicyclohexylamine) was accelerated by microwave irradiation at 150 °C to afford the corresponding allenes 2 in good to high yields in 1–10 min. Bisalkynes 5 and 7 were also converted to the corresponding bisallenes 6 and 8 in 63% and 61% yields, respectively, under the current condition.
3-allenic aromatic ethers with decent to excellent yields under mild reaction conditions has been described. A variety of synthetically useful functional groups are tolerated and the synthetic utility of this method has been demonstrated through a series of transformations of the allene moiety. By applying this reaction as the key step, the total syntheses of naturally occurring allenic aromatic ethers
The synthesis of regio- and stereoselective arylsubstitutedα,β-unsaturated aldehydes and ketones from activated allenes was achieved. This mild and non-metallic oxidation is exclusively driven by benign ambient air and triggered by visible light. The same starting materials under ideal anaerobic conditions led to the 2,3-diphenylselenation adduct with no trace of oxygenated products, demonstrating