Facile Synthesis of Natural Moracin Compounds using Pd(OAc)<sub>2</sub>/P(<sup>t</sup>Bu)<sub>3</sub>-HBF<sub>4</sub>as a Sonogashira Coupling Reagent
作者:Jae Jun Lee、So-Ra Yun、Jong-Gab Jun
DOI:10.5012/bkcs.2014.35.12.3453
日期:2014.12.20
An efficient and practical synthesis of natural moracins, which have diverse range of biological properties including anticancer, antioxidant, and antibacterial activities, has been achieved using $Pd(OAc)_2/P(^tBu)_3-HBF_4$ as a Sonogashira coupling reagent which solved the unreactive problems in case of higher electron density of haloaryl compounds in the reaction. Lowering electron density of halophenol with acetylation and changing Sonogashira coupling reagent from $PdCl_2(PPh_3)_2$ to $Pd(OAc)_2/P(^tBu)_3-HBF_4$ smoothly produce the benzofuran structures in the syntheses of moracins M, N and S. The electron deficient halobenzaldehyde, however, easily forms the benzofuran using original Sonogashira conditions, and utilized for the first synthesis of moracin Y.
一种高效实用的天然莫拉辛(moracins)合成方法已经实现,该类化合物具有抗癌、抗氧化和抗菌等多种生物活性。该合成使用了 $Pd(OAc)_2/P(^tBu)_3-HBF_4$ 作为Sonogashira耦合试剂,成功解决了在反应中卤代芳香化合物高电子密度所导致的不反应问题。通过对氯苯酚进行乙酰化以降低电子密度,并将Sonogashira耦合试剂从 $PdCl_2(PPh_3)_2$ 更换为 $Pd(OAc)_2/P(^tBu)_3-HBF_4$,顺利合成了莫拉辛M、N和S的苯并呋喃结构。然而,电子缺乏的卤代苯甲醛在原始Sonogashira条件下能容易地形成苯并呋喃,并用于首次合成莫拉辛Y。