Synthesis and Characterization of 2‐Pyridylsulfur Pentafluorides

Abstract

Current approaches to prepare SF5‐substituted heterocycles during the synthesis of targeted heterocyclic compounds require the use of SF5‐functionalized aryl or alkyne reagents or SF5Cl as a source of the SF5 functional group. Herein we report that excess oxidative fluorination of 2,2′‐dipyridyl disulfide with a KF/Cl2/MeCN system leads to the formation of thirteen new 2‐pyridylsulfur chlorotetrafluorides (2‐SF4Cl‐pyridines). These molecules are found to undergo further chlorine–fluorine exchange reactions by treatment with silver(I) fluoride enabling ready access to a series of ten new substituted 2‐pyridylsulfur pentafluorides (2‐SF5‐pyridines). This is the first preparatively simple and readily scalable example of the transformation of an existing heterocyclic sulfur functionality to prepare SF5‐substituted heterocycles.

Synthesis and Reactivity of a Bioinspired Molybdenum(IV) Acetylene Complex

“…The ligand 6-methylpyridine-2-thiol was synthesized from 6-methylpyridin-2-amine according to literature procedures. 44 , 45 It was then deprotonated with pure NaH in THF to give Na(6-MePyS) in quantitative yield. 36 The metal precursor complex [MoI 2 (CO) 3 (NCMe) 2 ] 46 was synthesized according to established procedures.…”

Pyridine-promoted dediazoniation of aryldiazonium tetrafluoroborates: Application to the synthesis of SF5-substituted phenylboronic esters and iodobenzenes

“…However, in recent years, the scientific community has been witnessing a renewed interest in this functional group. Synthetic methods towards aliphatic SF 5 -containing compounds are based on free radical addition of SF 5 Cl or SF 5 Br to unsaturated compounds [ 7 – 9 ], whereas aromatic derivatives are available either by the Umemoto’s two-step synthesis from diaryl disulfides or benzenethiols [ 10 – 12 ], or by the reaction of nitrophenyl disulfides with elemental fluorine [ 13 – 16 ]. Aromatic and heteroaromatic SF 5 compounds are mostly prepared by the derivatization of commercial nitro-(pentafluorosulfanyl)benzenes [ 14 , 17 – 27 ] and approaches from SF 5 -aliphatics have also been studied [ 28 – 30 ].…”

Ar-SF 4 Cl Deoxofluorination

“…Fifteen years later, Umemoto reported a practical method for the preparation of ArSF 4 Cl by the reaction of ArSSAr or aryl thiols (ArSH) with an excess amount of chlorine in the presence of potassium fluoride or cesium fluoride in dry acetonitrile between 0 C and room temperature [40,41] (Fig. 2) [18,24] (Fig. 3).…”

“…On the other hand, PySF 4 Cl is extremely sensitive to moisture and fumes when exposed to air. They react vigorously with water [18,24]. Thus, ArSF 4 Cl is considered to be a fluorinating reagent, while PySF 4 Cl is not useful for this purpose.…”