Synthesis of Substituted Pentafluorosulfanylpyrazoles Under Flow Conditions

J Org Chem. 2024 Mar 1;89(5):3552-3562. doi: 10.1021/acs.joc.3c02295. Epub 2024 Feb 8.

Abstract

The development of flow conditions for the synthesis of pentafluorosulfanylpyrazoles is reported. A range of alkyl- and aryl-substituted SF5-alkynes were used in combination with different diazoacetates for this transformation. The corresponding substituted SF5-pyrazoles were obtained in up to 90% yield (average of 74% for 21 examples) as a mixture of isomers (up to 73:27 ratio). Synthetic transformations starting from an SF5-containing pyrazole were also demonstrated.