CSe2-free synthesis of [1,3]diselenole-2-thione and its application to syntheses of iodinated tetraselenafulvalenes (TSeFs)

Abstract

We developed a new CSe2-free protocol for the synthesis of [1,3]diselenole-2-thione and converted it to tetraselenafulvalene derivatives without any selenium-sulfur exchange side reactions.

Hybrid Organic/Inorganic Supramolecular Conductors D2[Au(CN)4] [D = Diiodo(ethylenedichalcogeno)tetrachalcogenofulvalene], Including a New Ambient Pressure Superconductor

“…However, the main product of the reaction was the 1,3-thiaselenole-2-selone 2 (20 %) and the desired thione 1b was obtained in only 3 % yield. To avoid the unfavorable transformation of 1,3-diselenole-2-thione to 1,3-thiaselenole-2-selone, we changed the reaction sequence as well as the iodination of 1,3-diselenole-2-thione, [5] that is, LDA was added last to a solution of 1,3-diselenole-2-thione and 1,2-bis(selenocyanato)ethane. This inverted sequence afforded 1b without a selenium-sulfur exchange side reaction in a yield of under 5 %.…”

“…The residue was subjected to silica-gel column chromatography. The first yellow fraction eluted with CS 2 was 1b (6 mg, 3 %) as an ocher powder upon concentration, and the second orange band eluted with CS 2 3 (3.7 mL) was added dropwise over a period of 3 min to a refluxing solution of 7 [5] (100 mg, 0.22 mmol) and 4 [18] (82 mg, 0.26 mmol) in benzene (20 mL), followed by stirring under reflux for 3 h. The same procedure as for DIEDSS was adopted for the separation of the products. Evaporation of the second red-orange fraction afforded orange-brown crystals of DIEDS-STF (112 mg, 71 %).…”

“…The analytical data are identical to the reported data. [12] 4,5-Ethylenediseleno-1,3-thiaselenol-2-selone (2): A THF solution of LDA (0.75 , 1.2 mL, 0.92 mmol) was added to a solution of 1,3-diselenole-2-thione [5] (96 mg, 0.42 mmol) in THF (100 mL) at -78°C, and the resulting solution was stirred for 1 h at the same temperature. 1,2-Bis(selenocyanato)ethane [13] (157 mg, 0.66 mmol) was added to this reaction mixture in one portion.…”

“…A THF solution of LDA (0.40 , 2.8 mL, 1.1 mmol) was slowly added to a mixture of 1,3-diselenole-2-thione [5] (102 mg, 0.45 mmol) and 1,2-bis(selenocyanato)ethane [13] (129 mg, 0.54 mmol) in dehydrated THF (100 mL) at -78°C for a period of 5 min. The reaction mixture was stirred for 1 h at -78°C, then quenched by addition of H 2 O/THF (1 mL, v:v = 1:1) and warmed to room temperature.…”

“…(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) selone, together with its applications to the synthesis of 4,5-diiodo-1,3-diselenole-2-one [5] and 4,5-alkylenedichalcogeno-1,3-diselenole-2-ones. [6] Cross-coupling reactions using these 1,3-diselenole-2-ones provide a number of selenium analogues of DIETS, i.e., DIEDSS {2-(5,6-dihydro [1,3]diselenolo [4,5-b] [1,4] ylidene)-5,6-dihydro [1,3]diselenolo [4,5-b] [1,4]dithiine}, and DIEDSSe {2-(4,5-diiodo-1,3-diselenol-2-ylidene)-5,6-dihydro [1,3]diselenolo [4,5-b] [1,4]diselenine}, and these organic π-donors are suitable candidates for the exploration of novel supramolecular organic conductors and superconductors.…”