Stereoselective Double Spirocyclization of 2-Benzyl-3-alkynyl Chromone with Nitrone via Gold-Catalyzed Cascade Reactions.
Org Lett
; 26(31): 6675-6680, 2024 Aug 09.
Article
in En
| MEDLINE
| ID: mdl-39052520
ABSTRACT
A novel, highly stereoselective gold-catalyzed spirocyclization of 2-benzyl-3-alkynyl chromone with nitrone is described. This cascade reaction involves gold-catalyzed cycloisomerization, nitrone-olefin [3 + 2]-annulation, alkene oxidation, and rearrangement for the formation of spirocyclic products. Interestingly, the isoxazolidine ring generated from [3 + 2]-annulation donates oxygen to alkene to generate a new pyran-3(4H)-one and azetidine ring for dispiro-benzofuran formation upon heating. This work demonstrates the one-pot, gold-catalyzed, multiple-step reaction, and the reaction temperature directly affects the formation of spirocyclic products.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Org Lett
Journal subject:
BIOQUIMICA
Year:
2024
Document type:
Article
Country of publication:
United States