Synthesis Of Binary Perfluoroalkyl Sulfonimide And Its Application In Water Phase Catalysis

The development of synthesis and catalytic technologies focuses on the greening of organic chemical reactions.The use of green solvents such as water instead of toxic and harmful solvents in the reaction process,and the reduction of waste?organic?solvent emissions as much as possible during the post-treatment of the reaction are in line with the basic principles of green chemistry.In this paper,based on the good solubility of dimethyl sulfoxide,and the strong polarity of the sulfone group?S=O?to promote the organic reaction,a perfluoroalkylsulfonimide compound with rich S=O groups is used.As a catalyst,four kinds of binary perfluorobutylsulfonimide compounds were designed and synthesized.Such compounds contain strongly acidic N-H functional groups and are good Br?nsted acid catalysts.Multiple perfluorobutyl groups in the molecule overlap each other,forming a hydrophobic region in the aqueous phase,providing a micro-reaction site for organic substrates.The rich S=O groups show a clear synergistic catalytic effect during the catalytic process.Experiments show that the position of perfluorobutyl in the molecule is not tolerable,the overlap effect is different,and the effect on the aqueous phase catalysis is obviously different;the S=O group plays a key role in promoting the smooth progress of the reaction,which may be in the middle of the formed carbon cation The body has a stabilizing effect.1. Three different substituted benzenedisulfonyl perfluorobutylsulfonimides C₆H₄?SO₂NHSO₂C₄F₉?₂?2a:o-;2b:m-;2c:p-?were synthesized from different benzenedisulfonyl chloride At the same time,benzenesulfonyl perfluorobutylimine was synthesized as a control catalyst?C₆H₅SO₂NHSO₂C₄F₉,2d?.The structure of the compound was confirmed by methods such as ¹H/¹⁹F NMR,HR MS and FT IR.The acid strength was measured by ³¹P NMR?Gutmann method?,and the results showed that this class of compounds was slightly more acidic than concentrated sulfuric acid.The compound showed obvious Tyndall effect in the aqueous phase.The critical micelle concentration?CMC?of the ortho-substituted compound 2a was 1.03×10^-2 mol/L.2. the three-component Mannich reaction of p-toluidine,2,2-dimethoxyacetaldehyde,and acetophenone catalyzed by 4 kinds of synthesized compounds 2a-2d in the aqueous phase.The optimal conditions for catalysis are 2 mol%catalyst,Reaction 6 h 80 ? in water.The order of catalytic efficiency is 2a>2b>>2c>2d.In the aqueous phase,2a has the best overlapping effect of perfluorobutyl in the molecule,which can more effectively reflect the hydrophobic effect.The yield of 2a was 73%,and the catalytic efficiency was significantly better than dodecylbenzenesulfonic acid?DBSA,yield 29%?.This result indicates that the hydrophobic effect of the alkyl group is insufficient to determine the catalytic efficiency of the catalyst,and the abundant S=O groups provide synergistic catalysis during the reaction.Further substrate expansion,a total of 27 kinds of ?-substituted arylamino acetal compounds were synthesized,and the products were characterized by ¹H/¹³C NMR and HR MS characterization.3. The synthesized 4 compounds 2a-2d catalyzed the indole self-addition reaction in the aqueous phase.The optimal conditions for the catalysis is 10 mol%catalyst and 50? in water for 6 h.The order of catalytic efficiency is 2a>2b>>2c>2d.In the aqueous phase,2a has the best overlapping effect of adjacent perfluorinated chains in the molecule,which improves the hydrophobic effect of the catalyst.The catalytic yield of 2a is 71%,which is better than that of dodecylbenzene sulfonic acid?DBSA?and sulfuric acid,with a yield of about 38%.This result indicates that the 2a and 2b catalysts can provide a denser micellar environment in the aqueous phase and the sulfone-based structure plays a synergistic role in the reaction.Further substrate expansion,a total of 9 kinds of trimeric indole compounds were synthesized,and the products were characterized by ¹H/¹³C NMR for structural identification.Two model reactions,three-component Mannich reaction and indole self-addition,verified the NH acid catalytic activity,hydrophobic effect,and S=O group synergistic catalytic effect of the new catalysts 2a-2d in the aqueous reaction.This can provide ideas and reference basis for the design of green catalytic system,and also has enlightening significance for the theoretical development of collaborative catalysis.