[3 + 2] Annulations between indoles and α,β-unsaturated ketones: access to pyrrolo[1,2-a]indoles and model reactions toward the originally assigned structure of yuremamine
作者:Haokun Li、Zhonglei Wang、Liansuo Zu
DOI:10.1039/c5ra11904a
日期:——
A direct [3 + 2] annulation reaction between indoles and α,β-unsaturatedketones is reported, which allows for the efficient assembly of densely substituted, highly functionalized pyrrolo[1,2-a]indoles. Model reactions toward the originally assigned structure of yuremamine are also described, leading to the successful construction of the core with required functionality.
据报道吲哚和α,β-不饱和酮之间有直接的[3 + 2]环化反应,可以有效地组装密集取代的高度官能化的吡咯并[1,2- a ]吲哚。还描述了针对最初分配的紫杉胺结构的模型反应,从而成功构建了具有所需功能的核。
Chemoselective Cascade Synthesis of N-Fused Heterocycles via Silver(I) Triflate-Catalyzed Friedel-Crafts/N-C Bond Formation Sequence
An efficient cascade methodology toward chemoselective synthesis of N-fused heterocycles including 9H-pyrrolo[1,2-a]indole, 3H-pyrrolo[1,2-a]indole and 1H-pyrrolo[1,2-a]indole derivatives has been developed. This transformation proceeds via a silver(I) triflate-catalyzed consecutive Friedel–Crafts reaction/NC bond formation sequence between readily available propargyl alcohols and 3-substituted 1H-indoles
化学选择性合成N稠合杂环的有效级联方法,包括9 H-吡咯并[1,2- a ]吲哚,3 H-吡咯并[1,2- a ]吲哚和1 H-吡咯并[1,2- a ]已开发出吲哚衍生物。这种转变是通过三氟甲磺酸银(I)催化的连续Friedel-Crafts反应/ NC键在易于获得的炔丙醇和3取代的1 H-吲哚之间形成的顺序进行的。不仅可以根据炔丙醇的取代方式观察到极好的化学选择性,而且路易斯酸催化的NC键形成过程可以在无碱和无配体的条件下进行。
Efficient Synthesis of 9H-Pyrrolo[1,2-<i>α</i>]Indoles via Michael Addition-Condensation of 3-Substituted Indoles with α,β-Unsaturated Ketimines
By employing copper dibromide as a catalyst, Michael addition–condensation of 3‐substitutedindoles with α,β‐unsaturated ketimines was realized. The reactions afforded a large variety of 9H‐pyrrolo[1,2‐α]indoles with good yields (up to 99 %). In addition, a plausible reaction mechanism was proposed.