Aryl Radical Cyclizations: One-Pot Syntheses of Protoberberine and Pavine Alkaloids
作者:Kazuhiko Orito、Yoshitaka Satoh、Hidetoshi Nishizawa、Rika Harada、Masao Tokuda
DOI:10.1021/ol006213a
日期:2000.8.1
2-(2'-bromo-beta-phenethyl)isoquinolinium bromides 6 and their nor- and homoanalogues (10,11) induced 6-, 5-, and 7-exo radical closures in a one-pot manner to give protoberberines 2, dibenzo[b,g]indolizidine 14a and, dibenzo[a, h]-1-azabicyclo[5.4.0]undecane 15a, respectively. A one-pot radical cyclization of 1-(2'-bromobenzyl)isoquinoline methiodide 18a gave a pavine alkaloid, (+/-)-algemonine (19a).
在沸腾的苯中用AIBN-Bu(3)SnH处理2-(2'-溴-β-苯乙基)异咔唑7,得到的8-氧代丁苯橡胶3的收率很高。对2-(2'-溴-β-苯乙基)溴化异喹啉鎓6及其正和类似物(10,11)的类似处理以一锅方式诱导6-,5-和7-exo自由基封闭分别得到原小ber碱2,二苯并[b,g]吲哚唑烷14a和二苯并[a,h] -1-氮杂双环[5.4.0]十一烷15a。一锅法将1-(2'-溴苄基)异喹啉甲硫醇18a进行自由基环化,得到了一种牛类生物碱(+/-)-金刚烷(19a)。