Pd-catalyzed chemo-selective mono-arylations and bis-arylations of functionalized 4-chlorocoumarins with triarylbismuths as threefold arylating reagents
作者:Maddali L.N. Rao、Abhijeet Kumar
DOI:10.1016/j.tet.2014.07.059
日期:2014.9
4-chlorocoumarins were studied under palladium catalysis using triarylbismuths as threefold arylating reagents. The high reactivity of 4-chlorocoumarins was demonstrated delivering mono- and bis-arylation products in a chemo-selective manner. The reaction conditions employed are simple, robust and the threefold coupling reactivity of triarylbismuth reagents was witnessed with good to high yields in 2–4 h conditions
在钯催化下,使用三芳基铋作为三重芳基化试剂,研究了不同取代的4-氯香豆素的交叉偶联反应。证明了4-氯香豆素的高反应性以化学选择性方式递送单芳基化和双芳基化产物。所采用的反应条件简单,稳定,并且在2-4小时的条件下,三芳基铋试剂的三重偶联反应性得到了良好的证明。在合成一些天然存在的新黄酮(3.27 – 3.30)中探索了该方法的实用性。另外,4-芳基香豆素3.1产物是制备(R)-托特罗定的有用前体。