CS/KOH System-Promoted Stereoselective Synthesis of ()-Alkenes from Diarylalkynes and a "Hidden" Zinin-Type Reduction of Nitroarenes into Arylamines.

In this work, we present the CS/KOH system as a practical and efficient reductive medium for obtaining ()-alkenes from alkynes through a highly stereoselective semireduction reaction. This cost-effective system enabled successful semireduction reactions of diverse alkynes using water as a hydrogen source, yielding moderate to excellent yields. The versatility of this protocol is further demonstrated through the synthesis of relevant compounds such as pinosylvin and resveratrol precursors, along with the notable anticancer agent DMU-212.

Trithiocarbonate Anion as a Sulfur Source for the Synthesis of 2,5-Disubstituted Thiophenes and 2-Substituted Benzo[]thiophenes.

The trithiocarbonate anion (CS) was generated from CS and KOH in dimethyl sulfoxide by a simple method and used as a novel synthetic equivalent of the S for the synthesis of 2,5-disubstituted thiophenes from 1,3-butadiynes. Additionally, this system was employed for the metal-free synthesis of 2-substituted benzo[]thiophenes from 2-haloalkynyl (hetero)arenes. These compounds were obtained from a cheap and readily available sulfur source in moderate to good yields, with good functional group tolerance.