Research On Synthetic And Catalytic Properties Of NHC Based On Benze-dioxane And Benzo-9-Crown-3

Heterocyclic carbene(N-heterocyclic Carbene)is a class of relatively stable divalent carbon carbene.They could liganded with many metal elements and formed stable metal complexes.In organometallic chemistry,especially in organic catalysis it plays an very important role.In this paper,Two kinds of Heterocyclic imidazole salt ligands based on the benzo 9-crown-3 and benzodioxane were synthesized.These two newly imidazole salt ligands have a high degree of flexibility and a relatively rigid geometric and also contains a heterocyclic carbene precursor who has highly efficient catalytic properties,it can be applied as two new organic phase transfer catalyst in chemical catalyzed reactions.we have characterize their properties by single-crystal diffraction,nuclear magnetic resonance,infrared,etc.(A)We have prepared these two kinds of imidazole salt by the reaction of 1-(9-anthracene-methyl)imidazole and 4-bromomethyl-benzodioxane and 4-bromomethyl-benzo-9-crwon-3 in THF.These two kinds of new imidazolium salts were characterized by1 H NMR,13 C NMR,XRD diffraction,infrared and other means.(B)NHC-Ag complexes were obtained by these two kinds ofligands reacted with transitional metal silver and also characterized by NMR.(C)Using these two imidazole salt ligand as a pioneer of Nheterocyclic carbene ligands and Pd Cl2(CH3CN)2as a source of palladium,investigated the catalytic activity of these two ligands in the Suzuki coupling reaction,test its catalytic effect in a different base,reaction substrate,solvent and the catalyst.The experimenttal results show that KOH and DMF: H2O=1:1 were the optimal bases and solvents,these compounds exhibited good activity in Suzuki reaction with phenyboronic acid and bromobenzene or strong electron withdrawing group containing chlorobenzene.These researches provide a reliable experimental data for the further study of drugs,biological and heterocyclic carbene in organic catalysis provides...