Six-Membered Cyclic Amidines as Efficient Catalysts for the Synthesis of Cyclic Dithiocarbonates from Carbon Disulfide and Epoxides under Mild Conditions

Abstract

Six-membered cyclic amidines effectively catalyzed the reaction of carbon disulfide with epoxides under mild conditions, such as atmospheric pressure and ambient temperature, to give the corresponding cyclic dithiocarbonates (1,3-oxathiolane-2-thiones) in high yields.

Synthesis and applications of the sulfur containing analogues of cyclic carbonates

“…Meanwhile, in 2020, Endo and co-worker discovered that six-membered cyclic amidines efficiently catalyse (1.0-3.0 mol%) the cycloaddition of monosubstituted epoxides with CS 2 at ambient temperature. 79 An extensive substrate scope was reported, which demonstrated the wider applicability of this catalyst system. The most recent report of a catalyst system for the formation of 1,3-oxathiolane-2-thiones was disclosed by Whiteoak/Mosquera and co-worker in 2022.…”

Aminocyclopropenium as a novel hydrogen bonding organocatalyst for cycloaddition of carbon disulfide and epoxide to prepare cyclic dithiocarbonate

“…This is primarily due to the frequent scrambling of oxygen and sulfur atoms, leading to a decrease in the selectivity of the reaction, which was rst documented by Endo et al 24 For the insertion of CS 2 in epoxides, base catalysts were most frequently used. The nucleophilic base-activated carbon disul-de forms an adduct intermediate, and then the sulfur anion attacks the epoxide causing the ring-opening 20,23,[25][26][27][28][29][30][31] (Scheme 2a). The monofunctional metal halide offered a nucleophilic halide anion to open the three-membered ring of the epoxide 24,[32][33][34] (Scheme 2b).…”

“…For the insertion of CS 2 in epoxides, base catalysts were most frequently used. The nucleophilic base-activated carbon disulfide forms an adduct intermediate, and then the sulfur anion attacks the epoxide causing the ring-opening 20,23,25–31 (Scheme 2a). The monofunctional metal halide offered a nucleophilic halide anion to open the three-membered ring of the epoxide 24,32–34 (Scheme 2b).…”