作者:Barry M. Trost、Weiping Tang、F. Dean Toste
DOI:10.1021/ja054449+
日期:2005.10.1
tricyclic intermediate is available in six steps from 2-bromovanillin and the monoester of methyl 6-hydroxycyclohexene-1-carboxylate. This intermediate requires only two steps to convert to (-)-galanthamine. Using a Heck vinylation, we found that the fourth ring of codeine/morphine could be formed. The final ring formation involves a novel visible light-promoted hydroamination. Thus, six steps are required
通过采用 Pd 催化的不对称烯丙基烷基化 (AAA) 来设置立体化学,出现了一种用于合成阿片类和石蒜科生物碱的有效发散合成策略。详细讨论了三代加兰他敏的合成,特别关注钯催化的 AAA 反应和分子内 Heck 反应的范围。关键的三环中间体可从 2-溴香草醛和 6-羟基环己烯-1-羧酸甲酯的单酯通过六个步骤获得。该中间体只需两个步骤即可转化为 (-)-雪花胺。使用 Heck 乙烯基化,我们发现可以形成可待因/吗啡的第四个环。最后的环形成涉及一种新型的可见光促进加氢胺化。因此,