An efficient method for regio- and chemoselective Friedel-Crafts acylation of indole using acyl chlorides in the presence of ZrCl(4) has been discovered. It minimizes/eliminates common competing reactions that occur due to high and multiatom-nucleophilic character of indole. In this method, a wide range of aroyl, heteroaroyl alkenoyl, and alkanoyl chlorides undergo smooth acylation with various indoles without NH protection and afford 3-acylindoles in good to high yields.

A novel microwave-promoted protocol mediated by Mn(OAc) 3 was developed for the single-electron-transfer oxidative direct C-H bond arylation of (hetero)arenes with aryl and heteroarylboronic acids. Various electron-deactivated and electron-rich heteroarenes and benzene underwent successfully the direct arylation in this general process. The use of slight excess of heteroarene or benzene in this method was found to be sufficient.

An oxidative dearomatization chemistry of 2-arylindole via a unique pathway involving Pd-catalyzed C-H peroxygenation is documented. Coupled with cascade transformation, it provides a new route to access indolin-3-ones bearing a C2-quaternary functionality, including a chiral center (indoxyls), a motif prevalent in indole alkaloids but synthetically underexplored. The method is chemo- and regioselective and compatible with versatile substrates. A mechanism has been outlined on the basis of results of control experiments, isolation/use of intermediates, and spectroscopic studies.

Novel 2-aryl-3-arylamino-imidazo-pyridines/pyrazines that exhibit potent tubulin polymerization inhibition, anticancer activity, anti-migration of cancer cells, chromosomal damage, and apoptosis have been developed.