Hauser-Kraus Annulation Initiated Multi-Cascade Reactions for Facile Access to Functionalized and Fused Oxazepines, Carbazoles and Phenanthridinediones.
Chemistry
; 30(3): e202303517, 2024 Jan 11.
Article
em En
| MEDLINE
| ID: mdl-37946675
ABSTRACT
The Hauser-Kraus (H-K) annulation of N-unsubstituted 3-olefinic oxindoles with 3-nucleophilic phthalides triggers a cascade of ring expansion and ring contraction reactions through several regioselective steps in one pot. While oxazepines were isolated in the presence of stoichiometric amounts of base at room temperature, carbazoles and phenanthridinediones were the products in the presence of excess base and microwave irradiation. Mechanistic studies guided by stepwise reactions and control experiments revealed that the isolable oxazepine intermediate, formed via ring expansion of the H-K adduct, is the key precursor to carbazole and phenanthridinedione via decarboxylative regioselective cyclizations.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Chemistry
Assunto da revista:
QUIMICA
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Índia