发现在磷原子上带有环己基的二羟基叔苯基膦(Cy-DHTP)是钯催化由一锅法从2-氯酚和末端炔烃合成取代苯并[ b ]呋喃的强配体。该催化剂体系还适用于通过氯苯并[ b ]呋喃与硼酸的Suzuki-Miyaura交叉偶联从二氯苯酚一步法一锅合成二取代的苯并[ b ]呋喃。Cy-DHTP和XPhos这两种配体的使用是促进反应的关键。机理研究表明,Pd–Cy-DHTP催化剂是Sonogashira交叉偶联步骤中的活性物种,而Pd–XPhos催化剂则加速了Suzuki–Miyaura交叉偶联步骤。
2,3-Disubstituted benzofurans possessing 2-hydroxyphenyl moiety at the C-3 position were synthesized from readily available 2-chlorophenols and terminal alkynes by hydroxy-directed ortho-Sonogashira coupling and subsequent oxypalladation/reductive elimination, using Pd-dihydroxyterphenylphosphine catalyst. The catalyst accelerates not only the Sonogashira coupling but also the introduction of 2-hydroxyphenyl