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An Efficient, Solvent‐Free and Green One‐Pot Protocol for the Rapid Access to Polyfunctionalized Carbazoles
Author(s) -
Dagar Anuradha,
Biswas Soumen,
M.Mobin Shaikh,
Samanta Sampak
Publication year - 2016
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201601611
Subject(s) - carbazole , nitromethane , chemistry , nitro , aryl , alkyl , synthon , organic chemistry , indole test , solvent , combinatorial chemistry
The solvent‐free one‐pot π‐extension reaction of indole to carbazole has been carried out very efficiently on the surface of a basic alumina as an inexpensive reusable solid support by involving several 2‐(3‐formyl‐1 H ‐indol‐2‐yl)acetophenones/acetates and a wide range of 2‐aryl/hetero‐aryl/alkyl‐substituted nitroolefins (or in situ generated nitroolefins from aldehydes and nitromethane)/nitrodienes/chalcones/cinnamyl esters as acceptors under aerobic conditions. This oxidant‐free one‐shot protocol delivers high to excellent yields (76‐92 %) of a novel series of 3‐nitro/benzoyl/carboxylate carbazole derivatives in eco‐friendly and economical manners and allows a variety of sensitive functional groups on aromatic rings. Moreover, the synthesized 3‐nitrocarbazoles are valuable synthons for the easy access to tetra cyclic pyrido[3,2‐ c ]carbazoles, 3‐iodo/arylacetylenyl‐substituted carbazoles and ( Z )‐N‐carbazole‐substituted nitroenamine ( Z/E= 99:1).