A simple protocol for the synthesis of difluoromethylthiolated chromen-4-ones using elemental sulfur and ClCF2CO2Na as the difluoromethylthiolating agent is described. Three-component reactions of 2'-hydroxychalcones, ClCF2CO2Na, and sulfur under basic conditions using TEMPO as the oxidant afforded HCF2S-containing 4H-chromen-4-one and 9H-thieno[3,2-b]chromen-9-one derivatives in good yield. The protocol
Hydrogen sulfide (H2S) is a signaling gasotransmitter that plays important roles in modulating the functions of different systems. We have designed and synthesized a 3-hydroxychromone-based fluorescent probe A for H2S detection. Probe A is based on a H2S-induced thiolysis reaction and an excited-state intramolecular proton transfer (ESIPT) process. The probe shows high selectivity and sensitivity for