Synthesis of 3,4-Bis(Butylselanyl)Selenophenes and 4-Alkoxyselenophenes Promoted by Oxone®

Paola S Hellwig; Jonatan S Guedes; Angelita M Barcellos; Gelson Perin; Eder J Lenardão

doi:10.3390/molecules26082378

Synthesis of 3,4-Bis(Butylselanyl)Selenophenes and 4-Alkoxyselenophenes Promoted by Oxone^®

Molecules. 2021 Apr 19;26(8):2378. doi: 10.3390/molecules26082378.

Authors

Paola S Hellwig¹, Jonatan S Guedes¹, Angelita M Barcellos¹, Gelson Perin¹, Eder J Lenardão¹

Affiliation

¹ LASOL-CCQFA, Universidade Federal de Pelotas-UFPel, P.O. Box 354, Pelotas 96010-900, RS, Brazil.

Abstract

We describe herein an alternative transition-metal-free procedure to access 3,4-bis(butylselanyl)selenophenes and the so far unprecedented 3-(butylselanyl)-4-alkoxyselenophenes. The protocol involves the 5-endo-dig electrophilic cyclization of 1,3-diynes promoted by electrophilic organoselenium species, generated in situ through the oxidative cleavage of the Se-Se bond of dibutyl diselenide using Oxone^® as a green oxidant. The selective formation of the title products was achieved by controlling the solvent identity and the amount of dibutyl diselenide. By using 4.0 equiv of dibutyl diselenide and acetonitrile as solvent at 80 °C, four examples of 3,4-bis(butylselanyl)selenophenes were obtained in moderate to good yields (40-78%). When 3.0 equiv of dibutyl diselenide were used, in the presence of aliphatic alcohols as solvent/nucleophiles under reflux, 10 3-(butylselanyl)-4-alkoxyselenophenes were selectively obtained in low to good yields (15-80%).

Keywords: 1,3-diynes; electrophilic cyclization; heterocycle; organoselenium; selenophene.