Regio‐ and Stereoselective Synthesis of Dithiocarbonates under Ambient and Solvent‐Free Conditions

Abstract

AbstractHerein, we report on the utilization of readily available lithium tert‐butoxide as an efficient catalyst for the addition of carbon disulfide to terminal and internal epoxides under ambient conditions. Notably, the reaction proceeds regio‐ and stereoselectively. By applying the optimized conditions, 14 terminal and internal epoxides were converted. The desired cyclic dithiocarbonates were isolated in yields up to 95 % after simple filtration over silica. NMR spectroscopy experiments to identify the mode of activation were performed, and they indicated activation of carbon disulfide by the catalyst. The reaction of cis‐2,3‐butyleneoxide gave only the trans‐dithiocarbonate, whereas the conversion of (R)‐propylen oxide gave the respective thiocarbonate stereoselectively as one enantiomer (>99 % ee) in 87 % yield.