74617-16-6Relevant academic research and scientific papers
Preparation of (Pentafluorosulfanyl)benzenes by Direct Fluorination of Diaryldisulfides: Synthetic Approach and Mechanistic Aspects
Ajenjo, Javier,Klepetá?ová, Blanka,Greenhall, Martin,Bím, Daniel,Culka, Martin,Rulí?ek, Lubomír,Beier, Petr
, p. 11375 - 11382 (2019/08/20)
Direct fluorination of ortho-, meta- and para-substituted aromatic thiols and disulfides using elemental fluorine afforded substituted (pentafluorosulfanyl)benzenes. This work thus represents the first study of the scope and limitation of direct fluorination for the synthesis of new SF5-containing building blocks. Fluorinations in batch and flow modes were compared. A comprehensive computational study was carried out employing density functional and wave function methods to elucidate the reaction mechanism of the transformation of ArSF3 into ArSF5. Eliminating various nonradical pathways, it has been shown that the reaction proceeds by a radical mechanism, initiated by the attack of the F. on the ArSF3 moiety, propagated via an almost barrierless F2+ArSF4 .→ArSF5+F. step and terminated by the ArSF4 .+F.→ArSF5. Most of the calculated data are in very good agreement with experimental observations concerning the ortho-substituent effect on the reaction rates and yields.
Bromonitromethane. A Versatile Electrophile
Fishwick, Brian R.,Rowles, David K.,Stirling, Charles J. M.
, p. 1171 - 1180 (2007/10/02)
Pathways in reactions of bromonitromethane with a variety of nucleophiles have been investigated.With thiolates, the electrophilic centre is bromine and the initial products are disulphides.When the thiolate ion itself carries an electrophilic centre such as carbonyl or cyano β-to sulphur, the product is a nitrothiophene derived from subsequent reaction of the first-formed disulphide with nitronate ion displaced in the initial process.This provides a generalisation of earlier nitrothiophene synthesis by this route.In reactions with arenesulphinate ion, the electrophilic centre is also bromine and equilibration between the initial reactants and the initial products, sulphonyl bromide and nitronate ion, is established.The components of the equilibrium subsequently react either with each other or with the solvent.Reactions with sulphides are slow and distal substituents such as hydroxy- or cyano- so much reduce reactivity that no reaction is observed.Dimethyl sulfide attacks bromonitromethane at the carbon atom,and subsequent attack on the nitromethyl sulphonium salt initially formed gives methylthionitromethane and trimethylsulphonium bromide.Iodide ion attacks at bromine to give iodine, presumably via iodine bromide, but with tervalent phosphorus nucleophiles, attack is at oxygen giving the corresponding oxides and HCN in a double deoxygenation sequence.For hydroxide, methoxide and hydride ions (from sodium borohydride), nucleophilic attack is at hydrogen and the nitronate ion produced is inert to further attack.There is no evidence of carbene formation by α-elimination.When the anion of bromonitromethane is allowed to react with tributylboron, the anionic migration-displacement which follows boron-carbon bond formation, yields 1-nitropentane.The anion of bromonitromethane is unreactive towards aldehydes and electrophilic alkenes.
New Synthesis with Elemental Sulfur. - Preparation of 1,2-Benzisothiazoles and Some Secondary Reactions
Markert, Juergen,Hagen, Helmut
, p. 768 - 778 (2007/10/02)
The preparation of new 1,2-benzisothiazoles 2,3,5 and of thienoisothiazole 4 is described.The thioethers 8 have been obtained from 2 and 3 by ring opening with alcoholate and reaction with halomethyl compounds.On cyclisation, the thioethers 8 give the thionaphthenes 11.The ring systems of thionaphthenopyrimidines 10 and 12 have been prepared from 11.
