Ruthenium Hydride/Brønsted Acid-Catalyzed Tandem Isomerization/<i>N</i>-Acyliminium Cyclization Sequence for the Synthesis of Tetrahydro-β-carbolines
作者:Casper L. Hansen、Janie W. Clausen、Ragnhild G. Ohm、Erhad Ascic、Sebastian T. Le Quement、David Tanner、Thomas E. Nielsen
DOI:10.1021/jo402192s
日期:2013.12.20
reaction but also attractive possibilities for total synthesis, including rapid generation of molecular complexity and formation of quaternary stereogenic centers. TBHCs can also be accessed by harnessing the Suzuki cross-coupling reaction to the isomerization/N-acyliminium cyclization sequence. Finally, diastereo- and enantioselective versions of the title reaction have been examined using substrate control
本文描述了依靠氢化钌/布朗斯台德酸催化的烯丙基酰胺异构化为N-酰基亚胺离子中间体而合成1,2,3,4-四氢-β-咔啉(THBC)的有效串联序列系留于吲哚的亲核试剂。该方法不仅为传统的Pictet-Spengler反应提供了一种方便的“无醛”替代方法,而且为全合成提供了诱人的可能性,包括快速生成分子复杂性和形成四元立体异构中心。TBHC也可以通过将Suzuki交叉偶联反应用于异构化/ N-嘧啶环化序列。最后,分别使用底物对照(dr> 15:1)和不对称催化(ee高达57%)检查了标题反应的非对映体和对映体选择形式。