Pd(II)-Catalyzed One-Step Construction of Cycloalkane-Fused Indoles and Its Application in Formal Synthesis of (±)-Aspidospermidine
摘要:
A highly efficient, redox-free Pd(II)-catalyzed tandem cyclization reaction initiated by intramolecular amino-palladation of alkynes followed by nucleophilic addition to nitrites is developed. This method provides a versatile approach for the synthesis of six- to eight-membered ring-fused indoles in one step and has also shown advantages in the formal synthesis of (+/-)-aspidospermidine.
Concise Synthesis of Annulated Pyrido[3,4-<i>b</i>]indoles via Rh(I)-Catalyzed Cyclization
作者:Jonathan G. Varelas、Satyam Khanal、Michael A. O’Donnell、Seann P. Mulcahy
DOI:10.1021/acs.orglett.5b02807
日期:2015.11.6
The synthesis of pyridines bearing multiple ring fusions poses a considerable challenge for organic chemists. To address this problem, we describe the synthesis of a small library of pyrido[3,4-b]indoles via an efficient, five-step sequence. The key transformation is a Rh(I)-catalyzed [2 + 2 + 2] cyclization that forms three rings in one reaction flask. Our method is high yielding, accommodates a variety
带有多个环稠合的吡啶的合成对有机化学家提出了相当大的挑战。为了解决这个问题,我们描述了通过高效的五步序列合成一个小的吡啶并[3,4- b ]吲哚文库。关键的转化是Rh(I)催化的[2 + 2 + 2]环化反应,该环化反应在一个反应瓶中形成三个环。我们的方法收率高,可容纳各种官能团,并且随着环尺寸的增加,无熵成本。