作者:Tominari Choshi、Takuya Sada、Hiroyuki Fujimoto、Chizu Nagayama、Eiichi Sugino、Satoshi Hibino
DOI:10.1021/jo962038t
日期:1997.4.1
Total syntheses of carazostatin (1), hyellazole (2a), and carbazoquinocins B-F (3b-f) have been completed. The cross-coupling reaction between 3-iodoindole 8 and vinylstannane 11b gave the 3-alkenylindole 7. Treatment of 7 with ethynylmagnesium bromide, followed by etherification of the resulting alcohol 12 with MOMCl, yielded the 3-alkenyl-2-propargylindole 6. The compound 6 was treated with t-BuOK
Carazostatin(1),hyellazole(2a)和carbazoquinocins BF(3b-f)的总合成已完成。3-碘吲哚8和乙烯基锡烷11b之间的交叉偶联反应得到3-烯基吲哚7。用乙炔基溴化镁处理7,随后用MOMC1醚化所得醇12,得到3-烯基-2-炔丙基吲哚6。将化合物6在t-BuOH中在90℃下用t-BuOK处理,以通过烯丙基介导的电环反应与N-脱保护的咔唑13一起获得所需的咔唑4。衍生自4a或4c的咔唑13a经两步转化为三氟甲磺酸酯24。在钯催化剂的存在下,使三氟甲磺酸酯24与9-庚基-9-BBN或苯基硼酸进行Suzuki交叉偶联反应,以产生1-庚基咔唑25a和1-苯基咔唑25b。裂解25a的醚键产生了咔唑他汀(1)。切割25b的醚键,然后进行O-甲基化,得到乙酰唑(2a)。用苯硒酸酐氧化Carazostatin(1),得到咔唑喹啉C(3c)。以类似的方式,分别合成了咔唑喹啉B和DF(3b,df)。