198757-46-9Relevant academic research and scientific papers
α-Thioxothioamides: and Cycloaddition Reactions with Aryl Isothiocyanates and Phenyl isocyanates.
Marchand, Evelyne,Morel, Georges
, p. 623 - 634 (2007/10/03)
Aryl and methyl isothiocyanates react with 1,2-dithiocarbonyl compounds 2 to give a mixture of 2,3-dihydro-2-thioxothaizole 3 and 2-iminothiazole 5.The products ratios depend mainly on the nature of the starting R1NCS.We show that α-iminothioamides 4 are intermediates in the formation of cycloadducts 5.The results are explained by and additions to the C=N bond of the heterocumulene followed by ring contraction of the 2,3-dihydro-1,4,2-dithiazine 6 (sulfur extrusion) or cycloreversion of the 2-thioxothiazetidine 7 (CS2 elimination).The addition of 4 occurs exclusively on the carbon-sulfur bond of isothiocyanantes.Some differences are observed for additions of phenyl isocyanate to heterodienes 2 and 4.The regiochemical preferences in all cycloaddition and ring contraction reactions have been demonstrated. - Keywords: 1,4-dithiabutadiene; 4-aza-1-thiabutadiene; isothiocyanante; ring contraction by sulfur extrusion; 2-thioxothiazole; 2-iminothiazole.
