Tang Luning, Huang Hai, Xi Yang, He Guangke, Zhu Hongjun
Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, People's Republic of China.
Org Biomol Chem. 2017 Apr 5;15(14):2923-2930. doi: 10.1039/c7ob00381a.
An attractive and novel methodology involving Pd/Cu-catalyzed tandem head-to-tail dimerization/cycloisomerization of terminal ynamides for the synthesis of 3,5-disubstituted oxazolones was developed. Under Pd(PPh)Cl/CuI cooperative catalyzed reaction conditions, it provided efficient access to 5-vinyloxazolones with exceptional functional group tolerance and good chemoselectivity. The control experiments demonstrated that Pd(PPh)Cl serves a key role in the dimerization of terminal ynamides and shows low catalytic activity in the intramolecular cyclization. Moreover, the hetero-Diels-Alder reaction of product 5-vinyloxazolones was also described, which provided polycyclic oxazolones in good yield.
开发了一种引人注目的新颖方法，该方法涉及钯/铜催化的末端烯酰胺的头尾串联二聚化/环异构化反应，用于合成3,5-二取代恶唑酮。在Pd(PPh)Cl/CuI协同催化的反应条件下，该方法能够高效地合成5-乙烯基恶唑酮，具有出色的官能团耐受性和良好的化学选择性。对照实验表明，Pd(PPh)Cl在末端烯酰胺的二聚化反应中起关键作用，而在分子内环化反应中催化活性较低。此外，还描述了产物5-乙烯基恶唑酮的杂Diels-Alder反应，该反应能以良好的产率得到多环恶唑酮。
