Síntese de 1-Arilselenometil-[1,2,3]-triazois via Reações de Cicloadição 1,3-dipolar

Abstract

In this work, we described the use of organoselenium compounds in Click Chemistry by copper catalyzed 1,3-dipolar cycloaddition of alkynes with azidomethyl arylselenides . Firstly, arylselenolate anions, generated in situ by the reaction of diaryl diselenides with NaBH4 in EtOH, reacted with methylene chloride at reflux, affording chloromethyl arylselenides 1a-c in satisfactory yields after 12 hours. These compounds were easily converted to azidomethyl arylselenides 2a-c in excellent yields after reaction with sodium azide and 18-crown-6 in DMSO at room temperature. After that, these azidomethyl arylselenides 2a-c were converted to corresponding 1-(arylseleno-methyl)-1,2,3-triazoles 4a-o by reaction with terminal alkynes 3a-l using catalytic amount of Cu(OAc)2.H2O (5 mol%) and sodium ascorbate (10 mol%), in a mixture of THF/H2O (1:1) under air atmosphere at room temperature. Under this reaction conditions a range of 1-(arylseleno-methyl)-1,2,3-triazoles were obtained in a good to excellent yields. In addition, the reaction time of these reactions could be reduced to a few minutes using microwave irradiation. This methodology is efficient to synthesize new selenium-containing triazoles with potential application in biological studies.