Synthesis of Sulfonyl Fluorides from Tertiary Sulfonamides via N-Methylation Using Me-λ³-Iodane

Dedication

Dedicated to Professor Masakatsu Shibasaki on the occasion of his 80th birthday.

Abstract

N,N-Dimethyl tertiary sulfonamides were efficiently activated by Me-λ³-iodane through N-methylation, and the generated electrophilic sulfonyl ammonium salts were converted into sulfonyl fluorides in one pot. The use of Et3N·3HF as the nucleophilic fluoride source is key to obtaining good-to-high yields for various substrates. The optimized protocol enables the utilization of readily available and highly stable sulfonamides as a protecting group for the corresponding sulfonyl fluorides. We have demonstrated the multistep synthesis of sulfonyl fluorides, during which the sulfonyl moiety was protected from strong nucleophiles as a sulfonamide.

Keywords

Sulfonyl fluoride - Hypervalent iodine - Alkyl iodane - Sulfonamides - Alkylation - Fluorination

Publication History

Received: 01 December 2025

Accepted after revision: 07 January 2026

Article published online:
29 January 2026

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