PEG-400 as a recyclable solvent in the synthesis of β-arylthio-α,β-unsaturated esters, ketone and aldehyde under base and catalyst-free conditions

PEG-400 was used as a green and recyclable solvent in an efficient, simple and straightforward method for the synthesis of beta-arylthio-alpha,beta-unsaturated esters, ketone and aldehyde through the hydrothiolation of alkynes with arylthiols under base-and catalyst-free conditions. The reactions were performed under mild conditions and furnished selectively the respective (Z)-beta-arylthio-alpha,beta-unsaturated compounds from alkynyl esters and ketone, while from alkynyl aldehyde, the (E)-stereoisomer was obtained, in good yields and moderate reaction times. PEG-400 was reused in up 5 successive reactions without previous treatment, affording products in comparable yields. (C) 2016 Elsevier Ltd. All rights reserved.