Indole and Pyrrole Derivatives as Pre-photocatalysts and Substrates in the Sulfonyl Radical-Triggered Relay Cyclization Leading to Sulfonylated Heterocycles
A visible-light-induced method for the construction of heterocyclic scaffolds such as pyrido[1,2-a]indoles and indolizines via sulfonyl radical-triggered relay cyclization without employing any external photocatalyst has been developed. Preliminary mechanistic investigation indicated that indole and pyrrole derivatives could serve as pre-photocatalysts to promote the sulfonylation/cyclization, thereby
已经开发了一种可见光诱导的方法,用于在不使用任何外部光催化剂的情况下通过磺酰基自由基触发的中继环化构建吡啶并[1,2 - a ]吲哚和中氮茚等杂环支架。初步机理研究表明,吲哚和吡咯衍生物可以作为预光催化剂促进磺酰化/环化,从而为合成有价值的磺酰化杂环提供了一种简便的方法。
Tetrahydroxydiboron and Nickel Chloride Cocatalyzed Rapid Radical Cyclization toward Pyrrolizidine and Indolizidine Alkaloids
tetrahydroxydiboron and nickel chloride cocatalyzed radical cyclization cascade with a broad substrate scope and an ultrashort reaction time was developed. The mechanistic investigation indicated that the reaction might involve a homocleavage of tetrahydroxydiboron and nickel hydride intermediates. This approach enables the simple and efficient synthesis of a series of heteropolycycles.
A Modular Synthesis of the Rhazinilam Family of Alkaloids and Analogs Thereof
作者:Jazmín García-Ramírez、Luis A. González-Cortés、Luis D. Miranda
DOI:10.1021/acs.orglett.2c02446
日期:2022.11.11
A short, modular strategy for synthesizing three representative alkaloids of the (±)-rhazinilam family and 10 non-natural analogs is described. The protocol involves a radical addition/cyclization cascade reaction that assembles the tetrahydroindolizine system decorated with appropriate groups for a subsequent Pd-mediated cyclization, which generates the nine-membered lactam.
Synthesis of (±)-desethylrhazinal using a tandem radical addition-cyclization process
作者:Ehecatl Paleo、Yazmin M. Osornio、Luis D. Miranda
DOI:10.1039/c0ob00572j
日期:——
The indolizidine ring system present in (±)-rhazinal, was assembled using a xanthate-based sequential intermolecular radicaladdition-cyclization process. The novel (±)-desethylrhazinal was prepared in seven steps in approximately 12% overall yield from 2-formylpyrrole, using this strategy.