1‐Cyanalkyliden‐substituierte 1,3‐Dithietanone als Cyanthioketen‐Äquivalente. Umsetzung zu 1,3,5‐Dithiazin‐4‐onen und 2‐Azetidinthionen

Abstract

Die Thiolyse der 3,3-Dichloracrylonitrile 1 fuhrt zu Dithiolaten 3, die sich zu Keten-dithioacetalen 5 alkylieren oder mit Phosgen zu den Titelverbindungen 8 acylieren lassen. Das uber die 1-Cyanoalkylidene-substituted 1 ,IDithietanones as Cyanothioketene Equivalents. Conversion into 1,3,5-Dithiazin-4-ones and 2-Azetidinethiones Thiolation of 3,3-dichloroacrylonitriles 1 leads to dithiolates 3, which can be alkylated to give ketene dithioacetals 5 or acylated with phosgene to yield the title compounds 8. rert-Butyl(cyan0)-thioketene (912) formed via 12 + 21 cycloreversion of 8c was found to be highly unstable. However, dithietanone 8c can be used directly as thioketene equivalent in the reaction with dimethylamine or aminoazirines 28 to give thioamides 12b, 33,34, and the 3-thiazoline 30. On addition of azomethines 17 or 2-thiazolines 24 to 8c, 1,3,5-dithiazin-4-one derivatives 19 or 25 are formed via nucleophilic attack at C-2 of the four-membered ring. The constitution of 19e was proven by an X-ray structural investigation. In the presence of an electron-rich 6-aryl residue, heterocycles 19 easily eliminate carbon oxide sulfide to give the azetidinethiones 21d -f , h, which can be considered as [2 + 21 cycloadducts of thioketene 9 c with azomethines. On heating, 8c and the 2-thiazoline 24b react to give bicyclic 27, whose constitution could be derived from an X-ray study.Seit Cyanketene durch Thermolyse von 2,S-Diazido-I ,4-benzochinonen bequem zuganglich sind, zahlt vor allem tert-Butylcyanketen zu den am haufigsten benutzten Ketenen'). Versuche, das zum Vergleich interessierende tert-Butyl(cyan)thio keten (9c) durch Blitzthermolyse von 4-terr-Butyl-l,2,3-thiadiazol-5-carbonitri12) oder durch 0 Verlag

Alkynyl Silyl Sulfides as Versatile Thioketene Equivalents

“…[36][37][38][39] It was therefore an exciting observation that the cycloaddition of thioketenes 1b with azomethines 21 occurs across the C=C double bond of the thioketene to give the corresponding β-thiolactams 23 (Table 2). 4,9 Unfortunately, this strategy fails for unstable aldothioketenes 1b (R 2 = H), preventing access to the particularly interesting 3-monosubstituted β-thiolactams 23. 4 To avoid the difficulties of thionation chemistry and the handling of labile thioketenes, other cycloaddition routes to β-thiolactams can be envisaged.…”

“…4 Exceptions are confined to sterically highly screened dialkylthioketenes 5a and to bis(trifluoromethyl)thioketene. 5b However, some useful applications of thioketenes have been reported, such as the oxidation of sterically hindered thioketenes to form α-thiolactones, 6 a [2+1] cycloaddition with carbenes to form alkylidenethiiranes, 7,8 a [2+2] cycloaddition with azomethines to form β-thiolactams, 9 and 1,3dipolar cycloaddition reactions with diazoalkanes 10 or nitrile oxides. 11…”

Cyclothiomethylation of primary amines with formaldehyde and hydrogen sulfide to nitrogen- and sulfur-containing heterocycles (review)

“…Of special interest and promise among the various methods for the production of 1,3,5-dithiazinanes [23][24][25][26][27][28][29][30][31][32][33][34] is the simple and convenient method based on the multicomponent reaction of readily obtainable amines, formaldehyde, and H 2 S. This reaction, discovered by Wohl [23] more than 100 years ago, was not properly developed, and the few published data in a number of cases contain contradictory information.…”