(Propargylsulfanyl)-2-aza-1, 3, 5-trienes as a direct source for novel family of highly functionalized 4, 5-dihydro-1, 3-thiazoles. Issue 8 (23rd February 2017)

• Record Type: Journal Article
• Authors: Nedolya, Nina A.; Tarasova, Ol'ga A.; Albanov, Alexander I.; Klyba, Lyudmila V.; Trofimov, Boris A.
• Is Part Of: Tetrahedron. Volume 73:Issue 8(2017)
• Page Start: 1085
• Page End: 1097
• Publication Date: 2017-02-23
• Subjects: 5-Ethenylidene-4, 5-dihydro-1, 3-thiazoles -- (Propargylsulfanyl)-2-aza-1, 3, 5-trienes -- Alkoxyallenes -- Isothiocyanates -- Propargyl bromide; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2016.12.064
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: A novel, simple approach to 2-(1-alkoxyprop-1-enyl)-5-ethenylidene-4, 5-dihydro-1, 3-thiazoles has been disclosed through the reaction of (propargylsulfanyl)-2-aza-1, 3, 5-trienes (readily available from alkoxyallenes, isothiocyanates, and propargyl bromide) with potassium or sodium tert -butoxide (1.1–1.4 equiv) under mild conditions [DMSO/THF (∼1:4–5), ca. −30 °C, 15–30 min]. The process proceeds through deprotonation of an activated SCH2 group, followed by intramolecular [1, 5]-ring-closure. Unlike alkyl-, benzyl-, and allylsulfanyl-analogues, the exclusive or competitive formation of seven-membered azaheterocycles was not observed. Graphical abstract: