Fluorination of sulfanyl amides using difluoroiodoarene reagents

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Abstract

A range of sulfur-containing amides have been fluorinated with the hypervalent iodine difluoride reagents 1, and two principal reaction pathways identified. Cephalosporin esters 2 having a heteroatom in the α-position to sulfur undergo fluorination in DCM with cleavage of the carbon-sulfur bond to form novel fluorinated β-lactams 4. Sulfides with electron-withdrawing groups in the α-position undergo α-fluorination in a process analogous to the classical Pummerer reaction. This Fluoro-Pummerer reaction has been exemplified for a range of simple α-phenylsulfanylacetamides 14-19. When β-hydrogens are present in the substrate a different route is followed, with deprotonation by basic fluoride taking place to yield vinyl sulfides 41-43. When an excess of the fluorinating reagent is used these vinyl sulfides can undergo further reaction in a novel tandem Pummerer-Additive-Pummerer process to yield α,β-difluoro sulfides 45-47.

Bibliographical metadata

Original languageEnglish
Pages (from-to)2816-2826
Number of pages10
JournalJournal of the Chemical Society. Perkin Transactions 1
Issue number24
DOIs
StatePublished - 21 Dec 2002