The solvent-controlled chemoselective construction of C–S/S–S bonds via the Michael reaction/thiol coupling of quinoline-2-thiones

K2CO3-catalyzed thio-Michael addition using quinoline-2-thiones and alpha,beta-unsaturated carbonyl compounds was used to assess the chemoselective construction of C-S and S-S bonds under mild reaction conditions in different solvents. The C-S bond showed a better chemoselective construction in EtOH whereas the S-S bond showed a better chemoselective construction in 1,4-dioxane. The corresponding products, generated from the reaction, presented a significant solvent-controlling effect.