3-Selanyl- and 3-tellanylchalcogenophenes were prepared by the electrophilic cyclization of (Z)-chalcogenoenynes under ultrasound irradiation conditions. This green procedure was carried out using Oxone® as an inexpensive and non-toxic oxidant agent to promote the oxidative cleavage of Se−Se and Te−Te bonds. The electrophilic cyclization of (Z)-1-propylthio- and (Z)-1-butylselen-1-en-3-ynes was performed using the diaryl diselenide or ditelluride/Oxone®/ethanol system. The respective 3-arylselanyl and 3-aryltellanylthiophenes and selenophenes were obtained in 40 % to 87 % yield (16 examples). Similarly, 3-arylselanyl and 3-aryltellanyltellurophenes were synthesized by the cyclization of (Z)-1-butyltelluro-1-en-3-ynes, using glycerol as the solvent instead ethanol (5 examples; 28 % to 65 % yield). For the first time, Oxone® was used in the selective oxidative cleavage of the Te−Te bond in cyclization reactions.
Dichalcogenides/Oxone®-Mediated Cyclization of (Z)-Chalcogenoenynes under Ultrasound Irradiation
Rosati O.;Santi C.;
2020
Abstract
3-Selanyl- and 3-tellanylchalcogenophenes were prepared by the electrophilic cyclization of (Z)-chalcogenoenynes under ultrasound irradiation conditions. This green procedure was carried out using Oxone® as an inexpensive and non-toxic oxidant agent to promote the oxidative cleavage of Se−Se and Te−Te bonds. The electrophilic cyclization of (Z)-1-propylthio- and (Z)-1-butylselen-1-en-3-ynes was performed using the diaryl diselenide or ditelluride/Oxone®/ethanol system. The respective 3-arylselanyl and 3-aryltellanylthiophenes and selenophenes were obtained in 40 % to 87 % yield (16 examples). Similarly, 3-arylselanyl and 3-aryltellanyltellurophenes were synthesized by the cyclization of (Z)-1-butyltelluro-1-en-3-ynes, using glycerol as the solvent instead ethanol (5 examples; 28 % to 65 % yield). For the first time, Oxone® was used in the selective oxidative cleavage of the Te−Te bond in cyclization reactions.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
