Ca(II)-Catalyzed Cascade Reaction of Tryptamines with Propargylic Alcohols: Temperature-Driven Ring Opening and Closing via the Allene Migration Pathway for the Synthesis of Pyrrolo[1,2-a]indoles.
Org Lett
; 26(6): 1196-1200, 2024 Feb 16.
Article
em En
| MEDLINE
| ID: mdl-38305701
ABSTRACT
A temperature-dependent cascade of reactions between tryptamines and propargylic alcohols was developed to achieve selective formation of pyrroloindoline and pyrrolo[1,2-a]indole heterocycles by Ca(II) catalysis. The cascade consists of electrophilic addition of allene at the C3 carbon of indole followed by intramolecular cyclization at 60 °C to yield pyrroloindolines. Furthermore, simultaneous 1,2-allene migration and pyrrolidine ring opening were followed by intramolecular cyclization via C-N bond formation at reflux temperature to obtain pyrrolo[1,2-a]indole scaffolds. A wide range of substrates, a clean reaction profile, scalability, and good to excellent yields are the advantages of this protocol.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
Org Lett
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2024
Tipo de documento:
Article