A facile synthesis of sulfonate esters from phenols using catalytic KF/NFSI and K2CO3

An effective approach toward conversion of phenols to their benzene sulfonate esters by using N-fluorobenzenesufonimide (NFSI) and catalytic potassium fluoride is demonstrated. Mild reaction conditions, shorter reaction time, excellent yield and easy-to-handle reagents are the key features of the methodology. Mild reaction conditions have conferred wide substrate tolerability and sensitive substrates are well preserved during the reaction. Sulfonate ester formation is governed by benzenesulfonyl fluoride which is in situ generated after addition of KF to NFSI and KF is regenerated after sulfonylation when potassium carbonate is used as a base. Graphical Abstract