Lafzi F, Kilic H, Saracoglu N. Protocols for the Syntheses of 2,2'-Bis(indolyl)arylmethanes, 2-Benzylated Indoles, and 5,7-Dihydroindolo[2,3-
b]carbazoles.
J Org Chem 2019;
84:12120-12130. [PMID:
31454241 DOI:
10.1021/acs.joc.9b02124]
[Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The electrophilic substitution reaction of 4,7-dihydroindole with aryl-aldehydes as an electrophilic partner followed by an oxidation step to deliver 2,2'-bis(indolyl)arylmethanes was studied for the first time. The reaction afforded regioselectivity at the 2,2'-positions of indole in an operationally simple and inexpensive procedure with a variety of substrates. To the best of our knowledge, this is the first set of examples of 2,2'-bis(indolyl)arylmethanes obtained in a substituent-free manner. A facile method from dipyrromethanes to the corresponding 2-benzylindoles was also reported. In addition, 2,2'-bis(indolyl)arylmethanes were converted to 5,7-dihydroindolo[2,3-b]carbazoles.
Collapse