Fabio Marinelli
University of L’Aquila, Italy
Title: Synthesis of indole derivatives through transition metals-catalyzed cyclization of 2-alkynylaniline derivatives
Biography
Biography: Fabio Marinelli
Abstract
Indole derivatives are one of the most extensively studied class of heterocyclic compounds. The indole nucleus is a fundamental constituent of many natural and synthetic products with biological activity. Moreover, fused indole derivatives display a number of interesting pharmacological properties. Cyclization of 2- alkynylanilines catalyzed by transition metals represents a powerful tool for the build-up of the indole nucleus, and affords mainly 2-substituded indoles, although sequential functionalizations of nucleophilic 3-position have been reported. An useful development of this methodology is represented by Pd-catalyzed reaction of 2-alkynyltrifluoroacetanilides with a variety of organic electrophiles such as aryl, heteroaryl, alkyl and alkynyl halides, vinyl triflates, arenediazonium tetrafluoroborates, boronic acids, a-iodoenones and allyl esters. This approach is based on the activation of the triple bond towards intramolecular nucleophilic attack by –NHCOCF3 by means of coordination to an organopalladium(II) intermediate; sequential reductive elimination results in the formation of 2,3-disubstituted indoles bearing the organic moieties linked to the -3 position). Furthermore, this methodology allows a straightforward assembly of polycyclic indole derivatives such as indoloquinazolines, indoloquinazolinones, and indoloquinolines.