Über die Oxidationsprodukte von Thiocarbonsäureamiden, XXXI¹⁾ Darstellung und Strukturuntersuchung der Tetra‐ und Trialkylthioharnstoff‐S,S,S,‐trioxide

Abstract

1‐Chlor‐N,N,N',N'‐tetramethylformamidiniumchlorid (1) läβt sich mit Silbersulfit glatt zum Tetramethylthioharnstoff‐S,S,S‐trioxid (2) umsetzen. N,N,N',S‐Tetraalkylisothiuroniumjodide 3 ergeben mit Silbersulfit die Trialkylthioharnstoff‐S,S,S‐trioxide 4. ‐ Konfiguration und behinderte Rotation um die C2‐N‐Bindungen der Thioharnstoff‐S,S,S‐trioxide 4 werden 1H‐NMR‐spektroskopisch untersucht und die Ergebnisse mit den Erfahrungen an anderen Thioharnstoff‐S,S,S‐trioxiden verglichen.

Carbene Complexes of Nonmetals

“…Tetrasubstituted derivatives 173 have been prepared by methylation of 170 with diazomethane [240] or by reaction of 2-chloroamidinium chlorides 172 with silver sulfite. [241] A similar displacement reaction appears to be involved in the synthesis of 174 from carbene 136 and SO 2 X 2 (X ϭ Cl, F). [242] The crystal structures of 171 [243] and 174 [242] show CϪS bond lengths (171: 182.7 Scheme 31.…”

Tert-butyl hydroperoxide-promoted guanylation of amines with benzoylthioureas: Mechanistic insights by HRMS and1H NMR

“…Supported by previous results, Maryanoff and collaborators described that 2 and 3 equivalents of peroxide in a Na 2 MoO 4 ‐catalysed thiourea oxidation are the required stoichiometry just enough to convert 1 equivalent of thiourea to the respective aminoiminomethanesulphinic and aminoiminomethanesulphonic acids intermediates that were isolated in experiments performed under the absence of amine. These acids were used as guanylating agents for different amines.…”

Reactivity of Small Oxoacids of Sulfur

“…Tetraalkylthioureas, for example, tetramethylthiourea form in aqueous solutions relatively stable monoxides in the course of oxidation by bromine, bromate [50], chlorite [51], and hydrogen peroxide [52]; while formation of tetramethylthiourea dioxide and trioxide has not been observed at all. Indeed, higher oxides were earlier shown to be unavailable by means of oxidation of tetramethylthiourea by peroxides and alternative pathways of synthesis should be employed [53,54]. Tetramethylthiourea trioxide has been received in reaction between 1-chloro-tetramethylformamidinium chloride with silver sulfite [53].…”

“…Indeed, higher oxides were earlier shown to be unavailable by means of oxidation of tetramethylthiourea by peroxides and alternative pathways of synthesis should be employed [53,54]. Tetramethylthiourea trioxide has been received in reaction between 1-chloro-tetramethylformamidinium chloride with silver sulfite [53]. Formation of tetramethylurea and sulfate as the final products of oxidation of tetramethylthiourea [52], together with the absence of dioxide and trioxide, show that cleavage of C-S bond proceeds at the monoxide stage.…”