Pyrazole-Sulfone hybridization via silver-catalyzed regioselective aza-Michael addition of pyrazoles to vinyl sulfones: Synthesis of <i>N</i>-sulfonylethylated pyrazoles

In this research, the facile pyrazole-sulfone hybridization via Ag₂CO₃-catalyzed aza-Michael addition of pyrazoles to vinyl sulfones has been developed. The methodology offers an efficient and regioselective synthesis of <i>N</i>-sulfonylethylated pyrazoles as an important subset of pyrazole-sulfone hybrids and it featured mild reaction conditions, excellent yields and high regioselectivity (reaching the highest <i>N</i>¹/<i>N</i>² ratio of 25:1).