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

Abstract

The synthesis of cyclic thiocarbonates by the cycloaddition of carbon disulfide (CS2) to thiiranes in the presence of silica-immobilized amine catalysts was investigated. The catalytic activities of the silica-immobilized catalysts toward the synthesis of cyclic thiocarbonates were higher than the activities of their homogeneous counterparts. The silica-supported catalysts strongly accelerated the cycloaddition of CS2 to thiiranes, and the pseudo-first-order rate constant of the silica-immobilized catalyst was about 430 times larger than that of the corresponding homogeneous catalyst. The coexistence of the molecular catalyst species and the neighboring surface silanols on the catalyst support was found to be key to the reaction acceleration. In addition to providing improved catalytic activity, the solid-supported catalysts were also shown to be recyclable and reusable for at least five cycles.

Activation of CS2 with the 2H-Phosphindole Complex to Construct P,S-Polycycles

“…Because it is an abundant, inexpensive, and easy-to-handle liquid, the activation of CS 2 has attracted a great deal of attention in recent decades. The activation of CS 2 with transition metal complexes provided a variety of chemical transformations, including insertion, dimerization, disproportionation, and cycloaddition reactions, furnishing various sulfur-containing organic compounds. , Among these transformations, the cycloadditions with CS 2 are of particular interest because they allowed efficient construction of sulfur heterocycles . Furthermore, sulfur heterocycles exhibited many biological activities and pharmacological actions .…”

Organocatalytic selective coupling of episulfides with carbon disulfide for the synthesis of poly(trithiocarbonate)s and cyclic trithiocarbonates

“…Choi and coworkers immobilized amine into a silica support in an attempt at recycling the catalyst but the cyclic trithiocarbonates were contaminated with linear polymers. 43 Here we demonstrate that using an appropriate initiator with a more electronegative anion than Cl − and higher temperatures, the coupling of CS 2 with PS essentially yields cyclic trithiocarbonates. The activation energy for the formation of cyclic trithiocarbonates is such that above 60 °C with F − as the anion, back-biting reactions largely predominate over propagation.…”

Synthesis of Sulfur-rich Polymers: Copolymerization of Cyclohexene Sulfide and Carbon Disulfide Using Chromium Complexes

“…There is a need to use CS 2 as a sulfur feedstock in polymer synthesis for obtaining sulfur-rich polymers with high molecular weight. However, in the literature, many synthetic procedures have been reported for cyclic trithiocarbonates, − which are used as a chain-transfer agent in living polymerization and only few papers can be found for the synthesis of poly­(trithiocarbonates). In 2007, Nozaki et al reported the first example of copolymerization of propylene sulfide (PS) with CS 2 in the presence of the well-known catalytic system, (salphen)­CrCl as the catalyst, where salphen is N , N ′-bis­(3,5-di- tert -butylsalicylidene)-1,2-diaminobenzene (see catalyst 1 in Chart ) and [PPN]Cl (bis­(triphenyl-phosphoranylidene)­ammonium chloride) is the cocatalyst .…”