1,3-Dithiolium carbenes from acetylenes and carbon disulfide

Abstract

Carbon disulfide reacted with electron-deficient acetylenes to generate 1,3-dithiolium carbenes which formed compounds 1, 2, and 3 from hexafluoro-2-butyne and 6, 7, and 21 from dimethyl acetylenedicarboxylate. The 1,3-dithiolium carbenes were intercepted with alcohols to form 2-alkoxy-l ,3-dithioles and with phenols to form hydroxyaryldithioles. Aliphatic aldehydes and ketones produced acylmethylenedithioles. Aromatic aldehydes gave aroyldithioles. Olefins and carboxylic acids were also incorporated into the reactions and the products were identified. The heterocumulenes carbonyl sulfide and diisopropylcarbodiimide reacted differently

Fluorine Segregation in Crystalline Materials: Structural Control and Solid‐State [2+2] Cycloaddition in CF3‐Substituted Tetrathiafulvalene Derivatives

“…The preparations described are based on the reaction of the volatile hexafluorobutyne either with CS 2 , [31] metal complexes thereof as [(triphos)Ni(h 2 -CS 2 )] (triphos = 1,1,1-tris(diphenylphosphinomethyl)ethane), [32] or with boiling sulfur to give the corresponding bis(trifluoromethyl)dithiete [33] for further reaction. The preparations are therefore limited to this specific derivative, together with the added inconvenience of the availability and handling of this gaseous alkyne.…”

Trifluoromethyl-substituted tetrathiafulvalenes

“…This strong anodic shift is particularly noticeable in tetrasubstituted TTFs such as TTF(CO 2 Me) 4 [2–4], TTFCl 4 [5], TTF(CF 3 ) 4 [2], or TTF(CN) 4 [3], which oxidize into the radical cation at 0.80, 0.83, 1.05 or 1.12 V vs SCE respectively, to be compared with TTF itself which oxidizes at 0.33 V vs SCE. The associated instability of these radical species in moist air hindered in most cases their isolation in cation radical salts.…”

“…Following three decades of extensive work toward the elaboration of conducting radical cation salts from tetrathiafulvalene (TTF) derivatives with electron-rich alkyl (tetramethyltetrathiafulvalene: TMTTF, tetramethyltetraselenafulvalene: TMTSF) or thioalkyl (ethylenedithiotetrathiafulvalene: EDT-TTF, bis(ethylenedithio)tetrathiafulvalene: BEDT-TTF) substituents [ 1 ], investigations of radical cation salts of tetrathiafulvalenes functionalized by electron-withdrawing groups (EWG) are less documented, essentially because the presence of such substituents as halogen, acyl, ester, amide or nitrile on the TTF redox core dramatically increases its oxidation potential and destabilizes the radical cation form. This strong anodic shift is particularly noticeable in tetrasubstituted TTFs such as TTF(CO 2 Me) 4 [ 2 – 4 ], TTFCl 4 [ 5 ], TTF(CF 3 ) 4 [ 2 ], or TTF(CN) 4 [ 3 ], which oxidize into the radical cation at 0.80, 0.83, 1.05 or 1.12 V vs SCE respectively, to be compared with TTF itself which oxidizes at 0.33 V vs SCE. The associated instability of these radical species in moist air hindered in most cases their isolation in cation radical salts.…”

Five‐Membered Heterocycles with Two Heteroatoms: O and S Derivatives

“…This method can be used to afford TTFs with electron-withdrawing substituents in the ring. Acetylenes 212 and 213 react with CS 2 to give the TTFs 214 [183] and 215 (Scheme 11.64) [184].…”