| The bis（3-indolyl）methane（3,3′-BIM）is an important class of heterocycle compound,in which two 3-indolyl units are joined together by a simple or a substituted methylene bridge.It is found that 3,3′-BIM has important application value in biochemistry,pharmaceutical chemistry,material science and other fields.For example,the 3,3′-bis（3-indolyl）methane compounds have a versatile biological functions:inhibiting cancer cell growth,antiinflammatory,antifungal,regulating cell growth and differentiation.On the other hand,trifluoromethyl group can effectively enhance and modify metabolic stability,lipophilicity,and membrane permeability of the parent molecules due to its strong electron-withdrawing effect.Therefore,exploiting a direct and efficient strategy for the preparation of chiral trifluoromethylated bis（3-indolyl）methanes would be highly valuable.According to previous work,we developed the Ni（II）-（imidazoline-oxazoline）complex mediated highlystereoselectiveAF-CAreactionofindoleswithβ-CF3-β-（3-indolyl）nitroalkenes,affording a series of chiral bis（3-indolyl）methanes bearing a trifluoromethylated all-carbon quaternary stereocenter in generally good yields with excellent enantioselectivities（up to 98%yield and 94%ee）.In addition,both enantiomers of a given trifluoromethylated 3,3′-BIM were obtained with high ee via removal of the indole N-protection group in the F-C products.The main contents are as follows:Asymmetric Friedel-Crafts alkylation reaction of indoles with nitroalkenesAsymmetric Friedel-Crafts reaction of indoles（0.3 mmol）andβ-CF3-β-（3-indolyl）nitroalkenes（0.2 mmol）with was investigated.In the presence of6 mol%L1,5 mol%Ni（Cl O4）2·6H2O catalyst loading,toluene（2.0 m L）as solvent at70 oC for 24-62 h,36 optically active trifluoromethylated 3,3′-BIMs were successfully prepared in good yields with generally high enantioselectivity.Both the enantiomers of the given 3,3′-BIM were obtained via removal of the indole N-protection group in the F-C products. |
PDF Full Text Request