JOURNAL OF ORGANIC CHEMISTRY, cilt.84, sa.18, ss.12120-12130, 2019 (SCI-Expanded)
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.