Recent Advances in Nucleophilic Fluorination Reactions of Organic Compounds­ Using Deoxofluor and DAST

Abstract

Selective fluorination of organic compounds continues to be a stimulating and exciting area of research. While a variety of fluorinating reagents and methodologies have been developed to fulfill the increasing demand for site selective fluorination of organic compounds, applications of Deoxofluor and DAST continue to be used widely. Our interest in applying synthetic methods for introducing fluorine or a fluorinated group into a large variety of organic compounds encouraged this review which highlights recent progress in fluorination reactions using Deoxofluor [bis(2-methoxyethyl)aminosulfur trifluoride] and DAST (diethylaminosulfur trifluoride) as key nucleophilic fluorinating reagents. This review covers the literature for fluorination reactions of organic com-

Acyl Glycosides through Stereospecific Glycosyl Cross-Coupling: Rapid Access to C(sp3)-Linked Glycomimetics

“…A conversion of the ketone functionality into a CF 2 group is well-documented for S(VI) reagents. 102−104 Thus, DeoxoFluor 105 was mixed with catalytic (10 mol %) amounts of MeOH to convert ketones into the gem -difluorides 32 . Our initial concerns that the glycosidic bond might be unstable under these conditions were unwarranted—CF 2 -linked disaccharide 32e was prepared with DeoxoFluor in 51% without cleavage of the methyl glycoside.…”

Strategies for Nucleophilic C(sp3)–(Radio)Fluorination

“…Deoxyfluorination became truly popularized, however, with the discovery and development of S–F reagents. Notably, the introduction of diethylaminosulfur trifluoride (DAST) ( 7 ) has enabled access to primary, secondary, and tertiary fluoride products from both alcohol and carbonyl starting materials (Figure B). , However, reactions facilitated by DAST can also give rise to either undesired elimination or rearrangement products. Additionally, DAST rapidly disproportionates to an explosive degradation product upon heating, leading to safety concerns for reagent storage and process applications. , …”

Organofluorine chemistry: Difluoromethylene motifs spaced 1,3 to each other imparts facial polarity to a cyclohexane ring

“…It was prepared in an eight step synthesis [22]. At the outset we explored a more direct synthesis of this arrangement based on deoxofluorination of 1,3-diketones 5 with DAST or Deoxo-Fluor ® [23] (Scheme 1). An alternative route envisaged a fluorodesulfurisation using 1,3-bis-dithianes 6 as substrates [24] (Scheme 1).…”

“…An alternative route envisaged a fluorodesulfurisation using 1,3-bis-dithianes 6 as substrates [24] (Scheme 1). Both synthetic approaches have been widely used for the introduction of the CF 2 group in open-chain and (macro)cyclic systems [23–24], but not in a 1,3 relationship.…”