Efficient synthesis of 3-benzoyl Benzo[b]thiophenes and raloxifene via Mercury(II)-Catalyzed cyclization of 2-alkynylphenyl alkyl sulfoxides
作者:Shi-Ming Wen、Cheng-Han Lin、Chin-Chau Chen、Ming-Jung Wu
DOI:10.1016/j.tet.2018.03.067
日期:2018.5
intermediate, 4-methoxybenzyl 2-bromo-4-methoxyphenyl sulfoxide (6), respectively. It was found that compared with the o-sulfanyl aryl bromides, the sulfinyl group at ortho position accelerated the Sonogashira coupling reaction of aryl bromides. Thus, compound 6 was coupled with 3,4,5-trimethoxyphenyl acetylene, followed by mercury-catalyzed cyclization reaction afford compound 2 in 79% overall yield. Raloxifene
分别通过关键中间体4-甲氧基苄基2-溴-4-甲氧基苯基亚砜(6)合成了独特的选择性雌激素受体调节剂雷洛昔芬(1)和抗微管蛋白剂2。发现与邻硫烷基芳基溴化物相比,邻位的亚磺酰基加速了芳基溴化物的Sonogashira偶联反应。因此,将化合物6与3,4,5-三甲氧基苯基乙炔偶联,然后通过汞催化的环化反应以79%的总收率得到化合物2。由化合物6分四步制备雷洛昔芬(1),并通过与1-三甲基甲硅烷基-2-(4-叔丁基二甲基甲硅烷氧基)苯基乙炔的偶合反应,汞催化的环化反应,烷基化和去甲基化。