An Efficient Route to 2,6-Disubstituted Styrenes via the Palladium-Catalyzed [4 + 2] Cyclodimerization of Conjugated Enynes
作者:Vladimir Gevorgyan、Kazushi Tando、Naoyuki Uchiyama、Yoshinori Yamamoto
DOI:10.1021/jo980967+
日期:1998.10.1
via the palladium-catalyzed [4+2] homobenzannulation of conjugated enynes 4 was developed. In all cases, the reactions proceeded in regiospecific manner, affording the disubstituted styrenes, bearing various functional groups at the 2 and 6 positions of the benzene ring, as a single reaction product in good to excellent yields. Initial attempts at cross-cycloaddition of two different enynes indicated
开发了一种通过钯催化共轭烯炔4的[4 + 2]均苯并苯合反应合成2,6-二取代苯乙烯5的有效且通用的方法。在所有情况下,反应都以区域特异性方式进行,以良好的收率得到了在苯环的2和6位带有多个官能团的双取代苯乙烯,作为单一反应产物。对两种不同的炔烃进行交叉环加成的初步尝试表明该过程的化学选择性较低。因此,在所有情况下,交叉二聚产物6都伴随着显着量的化学异构体同二聚体5。