Nucleophilic aromatic substitution of the nitro group of para- and meta-nitro-(pentafluorosulfanyl)benzene with alkoxides and thiolates generates a range of substituted 4- and 3-(pentafluorosulfanyl)benzenes in a single-step reaction.
Vicarious nucleophilic substitutions (VNS) of hydrogen in 1-nitro-4-(pentafluorosulfanyl)benzene with carbanions provide 2-substituted 1-nitro-4-(pentafluorosulfanyl)benzenes in good to high yields. VNS of 1-nitro-3-(pentafluorosulfanyl)benzene gives a mixture of 6- and 4-substituted 1-nitro-3-(pentafluorosulfanyl)benzenes in 85:15 to >98:2 ratio and good to high yields. In basic media, the VNS reactions lead to the formation of carbanions that can be alkylated by alkyl halides affording the corresponding alkylated products in moderate yields. Transformation of primary products to substituted (pentafluorosulfanyl)anilines and 3- or 4-substituted (pentafluorosulfanyl)benzenes is also described.
Summary
Meta- or para-nitro-(pentafluorosulfonyl)benzenes underwent the Davis reaction with arylacetonitriles to provide the SF5-containing benzisoxazoles. Good yields were obtained with arylacetonitriles containing the electron-neutral or electron-donor group, while those with the electron-acceptor group were found to be unreactive. Reductions of the benzisoxazoles gave ortho-aminobenzophenones in high yields. Their synthetic utility was demonstrated by condensation reactions with carbonyl compounds or amines to provide SF5-containing quinolines and quinazolines, respectively.
Abstract1‐Nitro‐4‐(pentafluorosulfanyl)benzene underwent direct amination with 1,1,1‐trimethylhydrazinium iodide in the presence of tBuOK in DMSO to give 2‐nitro‐5‐(pentafluorosulfanyl)aniline in good yield. 1‐Nitro‐3‐(pentafluorosulfanyl)benzene, under similar conditions, gave 2‐nitro‐4‐(pentafluorosulfanyl)aniline, also in good yield. Reduction of either product with hydrogen in the presence of Raney nickel provided 4‐(pentafluorosulfanyl)benzene‐1,2‐diamine, which served as a precursor for the efficient synthesis of SF5‐containing benzimidazoles, quinoxalines, and benzotriazoles.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.