Sustainable and practical semi-heterogeneous photosynthesis of 5-amino-1,2,4-thiadiazoles over WS2/TEMPO

An eco-friendly and practical method for the clean preparation of 5-amino-1,2,4-thiadiazoles was developed. With WS2 as the semiconductor photocatalyst, both TEMPO and O2 (in air) as the redox catalysts, a variety of thiadiazoles were semi-heterogeneously formed in high to quantitative yields and could be easily collected by CPME extraction and rinsing. Furthermore, the catalytic system can be reusable for at least 5 reaction runs.