Diastereoselective Synthesis of Tetrahydrospiro[carbazole-1,3'-indolines] via an InBr3-Catalyzed Domino Diels-Alder Reaction.
J Org Chem
; 86(8): 5616-5629, 2021 Apr 16.
Article
in En
| MEDLINE
| ID: mdl-33818095
ABSTRACT
A simple InBr3-catalyzed domino reaction of indoles, phenylacetylenes, and various 3-methyleneoxindolines in toluene is described. This reaction not only provided a convenient synthetic protocol for polysubstituted tetrahydrospiro[carbazole-1,3'-indolines] in good yields but also gave completely different diastereoisomers of the tetrahydrospiro[carbazole-1,3'-indolines] to that of the previously reported TfOH-catalyzed one-pot reaction of indoles, acetophenones, and 3-methyleneoxindolines. Additionally, the InBr3-catalyzed reaction of the initially prepared 1,1'-bis(indolyl)phenylethanes with 3-phenacylideneoxindolines also gave the corresponding tetrahydrospiro[carbazole-1,3'-indolines] in good yields and with excellent diastereoselectivity. The reaction mechanism involved the sequential in situ generation of reactive dienophilic 3-alkenylindole, the Diels-Alder reaction, and the Lewis acid controlled diastereoisomerization process.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
J Org Chem
Year:
2021
Document type:
Article
Affiliation country:
China