Convenient synthesis of 1,3-dithiolane-2-thiones: cyclic trithiocarbonates as conformational locks

Abstract

A series of novel 1,3-dithiolane-2-thiones, or cyclic trithiocarbonates, has been prepared by a new simple procedure: a treatment of the corresponding epoxides with the commercially available potassium ethyl xanthogenate, KSC(S)OEt. The stereochemistry of the products was determined by 1 H NMR and in some cases by single-crystal X-ray data. Cyclohexane-based 1,3-dithiolane-2-thiones revealed a trans-fusion of the carbo-and hetero-cycles. The products obtained from the mono-substituted cyclohexene oxides demonstrated an axial position of the substituents. Thus the epoxide transformation into trithiocarbonate can be used as a method for locking cyclic compounds in unstable conformations.

Metal–Organic Frameworks of Cu(II) Constructed from Functionalized Ligands for High Capacity H2 and CO2 Gas Adsorption and Catalytic Studies

“…On increasing the temperature to 30 °C, still the mixture was obtained. On further increasing the temperature to 80 °C, thin-layer chromatography (TLC) showed a single major spot, which was passed through a short plug of silica using CH 2 Cl 2 as an eluent and characterized by 1 H NMR (Figures S36–S40) and matched with the reported literature, which confirmed the formation of exclusive cyclic trithiocarbonate (Table ). In some cases, crystals appeared after some time.…”

3,5-Dithiatricyclo[5.2.1.02,6]decan-4-one

“…Rather surprisingly, a search of the Cambridge Structural Database (CSD, March 2020 update) revealed only five previous structures containing the 1,3-dithiolan-2-one fragment with at least one sp 3 carbon in the ring (Figure 3). These are the parent compound 6 [10], the polychlorinated compound 7 in which the dithiolanone ring is tetrasubstituted [11], the bicyclic diester 8 with a trans-disubstituted dithiolanone ring [12], and the Diels-Alder dimer of 4,5bis(methylene)-1,3-dithiolan-2-one 9 and the derived cobalt complex 10 [13], both of which have the dithiolanone ring fully substituted but with one spiro sp 3 centre and one sp 2 centre. Figure 1.…”

Synthesis of Cyclic Thiocarbonates from Thiiranes and CS2 with Silica-Immobilized Catalysts

“…The reaction of various thiiranes or epoxides with CS 2 was carried out in a similar manner. Authentic samples of cyclic trithiocarbonates were prepared according to the literature . The signals of cyclic trithiocarbonates for NMR were assigned according to the previous report. , …”

“…Authentic samples of cyclic trithiocarbonates were prepared according to the literature. 32 The signals of cyclic trithiocarbonates for NMR were assigned according to the previous report. 32,33 ■ RESULTS AND DISCUSSION Characterization of Silica-Immobilized Catalysts.…”

“…32 The signals of cyclic trithiocarbonates for NMR were assigned according to the previous report. 32,33 ■ RESULTS AND DISCUSSION Characterization of Silica-Immobilized Catalysts. Amino-or quaternary ammonium-immobilized silica catalysts were prepared by reacting trialkoxysilane-type coupling reagents with mesoporous silica (MS-1 and MS-2) or amorphous silica (AS-1 and AS-2).…”