Sonochemistry: An efficient alternative to the synthesis of 3-selanylindoles using CuI as catalyst

Abstract

Ultrasonic (US) irradiation was successfully used as an alternative energy source to prepare 3-selanylindoles through the direct selanylation of indoles with diorganyl diselenides using CuI (20 mol%) as catalyst and DMSO as the solvent. By using this US-promoted reaction, eleven 3-organylselanylindoles were prepared selectively and in good yields. A comparative study between the reactions under conventional heating, microwave and ultrasound irradiations was performed, and it was observed advantage in using US over the other heating systems.

Ultrasound‐Assisted Multicomponent Reactions, Organometallic and Organochalcogen Chemistry

“…About indoles 82 a , 82 b , 82 d , 82 e and 82 g , it is important to underline how the use of SeO 2 in the reaction mixture has increased the yields while reduced the reaction time, as can be evidenced by comparing these results to those obtained in a previous work (Scheme ) …”

Ultrasound‐Promoted Radical Synthesis of 5‐Methylselanyl‐4,5‐dihydroisoxazoles

“…Sonochemistry can accelerate and modify the course of reactions and even generate intermediates that would not be feasible in conventional synthesis . Recently, our research group has described the efficient synthesis of 3‐selanylindoles and selenium‐containing chrysin derivatives using ultrasonic irradiation.…”

Selective synthesis of 3‐Selanylindoles from Indoles and Diselenides using IK/mCPBA system

“…There are some methods for synthesis of 3‐selanylindoles, besides the electrophilic cyclization of 2‐alkynylanilines, the main route for obtaining them is the use of easily available indole as starting material. Recently, using Cu‐catalysts to improve the selenation of indoles has become the important methodology for the preparation of 3‐selanylindoles . Wu and co‐workers reported the CuO‐catalyzed three‐component reaction using selenium powder as selenium source .…”

“…Wu and co‐workers reported the CuO‐catalyzed three‐component reaction using selenium powder as selenium source . Under ultrasonic (US) irradiation, the selenation of indoles with diselenides catalyzed by CuI was also described . On the other hand, using metal‐like behavior of molecular iodine as catalyst, under microwave (MW) irradiation this protocol can promote the direct reaction of indoles with diselenides .…”