Tsukamoto Hirokazu, Kondo Yoshinori
Graduate School of Pharmaceutical Sciences, Tohoku University, Aramaki-aza aoba 6-3, Aoba-ku, Sendai 980-8578, Japan.
Org Lett. 2008 Jul 3;10(13):2633-6. doi: 10.1021/ol800509z. Epub 2008 May 30.
A palladium(0)/monophosphine catalyst promotes a novel arylative cyclization reaction of C1-, C2-, and C3-tethered allenyl enones with arylboronic acids to produce five-membered ring containing products. The regioselectivity of the process, associated with aryl group introduction into the allene moiety, depends on the length of the tether. This finding suggests that the cyclization reaction does not proceed through a carbopalladation pathway but rather via a route involving palladacycle-forming or "anti-Wacker"-type oxidative addition to the Pd(0) catalyst.
钯(0)/单膦催化剂促进了C1-、C2-和C3-连接的烯丙基烯酮与芳基硼酸的新型芳基化环化反应，生成含五元环的产物。该过程的区域选择性与芳基引入丙二烯部分有关，取决于连接链的长度。这一发现表明，环化反应不是通过碳钯化途径进行的，而是通过一条涉及形成钯环或对Pd(0)催化剂进行“反瓦克”型氧化加成的途径进行的。
