The Preparation Of Amphiphilic Di-perfluoroalkyl Sulfonyl Benzoyl Imide And Its Aqueous Catalytic Application In Synthesis Of Indoles

Aqueous reaction brings many advantages such as low cost,safety,and environmental friendliness,and is considered green and ideal for laboratory and industry processes.In this paper,a type of fluorous amphiphilic Br?nsted acids,aromatic perfluoroalkylsulfonimides have been designed and synthesized.The acids contain the hydrophilic sulfonimide acid group,which catalyze the organic reactions.Additionally,the acids combine fluorine-containing group and the benzene ring segments,which form micelle aggregate phase in the aqueous solution to provide the reaction location.This kind of compounds are thus hydrophilic and lipophilic.The main work is as follows:1.Two perfluoroalkyl sulfonamides are obtained through two-step reaction by using two different fluorosulfonyl fluorides and potassium sulfonates;chlorotrifluorosulfonic acid is reacted with phenyl trichloromethane to obtain intermediate 3-?chlorosulfonyl?benzoyl chloride;The acyl chloride is then reacted with perfluorosulfonamide to obtain the perfluoroalkanesulfonyl phthalimide intermediate.After acidification,two target perfluoroalkylsulfonphthalimides are obtained.Among them,trifluoromethylsulfonphthalimide was unstable and no pure product was obtained;the pure product,perfluoro-n-butylsulfonphthalimide 4a,had an overall yield of 36%.2.The intermediates and target compound 4a were characterized by NMR and HR MS.The H₀ value of the target compound 4a was determined using the Hammett acidity function;the change in the chemical shift of ³¹P NMR of 4a was measured by the Gutmann method,and Et₃P=O was used as the probe molecule;the conductivity of the 4a solution was determined by conductometric titration.The three measurements show that 4a is a strong acid that is slightly more acidic than H₂SO₄.The Tyndall effect,particle size distribution,and critical aggregation concentration were measured on the aqueous solution of 4a.The results showed that 4a formed micelles in aqueous solution,its hydrated size of the aggregation centered on 324 nm,and the critical aggregation concentration of micelles was15.8 mmol/L.3.The Michael addition reaction of the substituted indoles with the?,?-unsaturated carbonyl compound was used as a template reaction to investigate the catalytic activity of the target compound on this reaction.Using water as the reaction medium,17 catalytic reactions were performed.Among them,the yield of mono-substituted?,?-unsaturated ketones is distributed in 82-98%;the yield of the?,?-unsaturated ketones with large catalytic hindrance is reduced,and the yield in water is approximately 80%in tetrahydrofuran.The yield of the reaction in alcohols and nitriles is below 60%.Comparison experiments with other Bronsted acids showed that the micelle structure formed in the aqueous phase of 4a can effectively promote the reaction.4.Alkylation with aldehydes/ketones,Friedel-Crafts alkylation with substituted indoles.The alkylation reaction of aldehydes was carried out at 30°C in water with a trace of ethyl acetate,and the reaction was performed at a stoichiometric ratio.The catalyst was 1 mol%.11 kinds of 3,3'-bis-indenyl hydrocarbons were synthesized.The yields are between 87-99%.The product can be purified simply by washing and vacuum filtration.Ketone as alkylation reagent,pure water as solvent,indoles and ketone charge ratio of 1:2,5 mol%of catalyst,reaction at 30°C,8 kinds of 3,3'-bis-indenyl hydrocarbon compounds were synthesized.The yields are at least 80%.Methanol was used as a solvent to synthesize 21alkylated products with a yield ranging from 59%to 99%.Reaction of different substituents in acetone yields 23-77%yield of quinone tricyclic derivatives.In this aqueous reaction,the new catalyst is also superior to other acid catalysts.