Cationic Multidentate Halogen-Bond Donors in Halide Abstraction Organocatalysis: Catalyst Optimization by Preorganization
作者:Stefan H. Jungbauer、Stefan M. Huber
DOI:10.1021/jacs.5b07863
日期:2015.9.23
show that the catalytic activity is based on halogen bonding using, e.g., the chlorinated derivatives as reference compounds. On the basis of these studies, halobenzimidazolium organocatalysts were then investigated. Monodentate compounds featured the same trends as the corresponding imidazolium analogues but showed a stronger catalytic activity. In order to prepare bidentate versions which are preorganized
The fluorine-pentafluorophenyl substitution reaction in anhydrous hydrogen fluoride (aHF): a new interesting methodical approach to synthesize pentafluorophenylxenonium salts
作者:Hermann-Josef Frohn、Thorsten Schroer
DOI:10.1016/s0022-1139(01)00526-7
日期:2001.12
In anhydrous hydrogen fluoride (aHF) (heterogeneous reaction) B(C6F5)3 transfers all the three aryl groups to XeF2 forming [C6F5Xe]+ salts. Upon addition of KF, the [C6F5Xe] [HF2] salt was isolated in 78.7% yield. [C6F5Xe] [HF2] dissolved in MeCN exhibits significant cation–anion interactions and decomposes within 14 days at 20 °C. The acidity of the aHF solvent determines the nature of the products
在无水氟化氢(aHF)中(非均相反应),B(C 6 F 5)3将所有三个芳基转移到XeF 2上,形成[C 6 F 5 Xe] +盐。加入KF后,分离出[C 6 F 5 Xe] [HF 2 ]盐,收率为78.7%。溶于MeCN的[C 6 F 5 Xe] [HF 2 ]表现出显着的阳离子-阴离子相互作用,并在20°C下在14天内分解。aHF溶剂的酸度决定XeF 2与B(C 6 F 5)反应中产物的性质)3。讨论了在aHF中这种氟-芳基取代的新方法方法的反应路径。