Reactivity of Organolithium Reagents to 2,3,4,5-Tetraphenylcyclopentadienone and Crystal Structures of Addition Products  

作　　者：ZHANG Xiaoyong HAN Limin ZHU Ning GAO Yuanyuan SUO Quanling 

机构地区：[1]Chemical Engineering College, Inner Mongolia University of Technology, Hohhot 010051, P. R. China [2]Department of Chemistry, Baotou Teacher's College, Baotou 014030, P. R. China

出　　处：《Chemical Research in Chinese Universities》2015年第5期736-741,共6页高等学校化学研究（英文版）

基　　金：Supported by the National Natural Science Foundation of China（Nos.21266019, 21062011） and the Inner Mongolia Auto- nomous Region Higher Scientific Research Project, China（No.NJZY14060）.

摘　　要：The conjugate addition reactions of four organolithium reagents to 2,3,4,5-tetraphenylcyclopentadienone （tetracyclone） were investigated to reveal the reactivity of organolithium reagents to tetracyclone. The results show that 1,2-addition products 2,3,4,5-tetraphenyl-1-（2-thienyl）-2,4-cyclopentadien-l-ol（1）, 1-n-butyl-2,3,4,5-tetraphenyl- 2,4-cyclopentadien-l-ol（2） and 1,2,3,4,5-pentaphenyl-2,4-cyclopentadien-1-ol（3） were synthesized in excellent yields while tetracyclone reacted with 2-thienyllithium, n-butyllithium and phenyllithium, respectively. Interestingly, three 1,2-, 1,4- and 1,6-addition isomers 1-tert-butyl-2,3,4,5-tetraphenyl-2,4-cyclopentadien-1-ol（4）, 4-tert-butyl-2,3,4,5- tetraphenyl-2-cyclopenten-1-one（5） and 2-tert-butyl-2,3,4,5-tetraphenyl-3-cyclopenten-1-one（6）, were simultaneously obtained by the conjugate addition reaction of tert-butyllithium with larger steric hindrance to tetracyclone. Compounds 1-6 were characterized by ^1H and ^13C NMR spectra, Fourier transform infrared（FTIR） spectra and mass spectra（MS）. The crystal and molecular structures of compounds 1, 2 and isomers 5, 6 were determined by X-ray single crystal diffraction technique. The results imply that the steric hindrance of tert-butyllithium probably play a key role in controlling the conjugate addition reaction. The conjugate addition mechanism of organolithium reagents to tetracyclone was proposed.The conjugate addition reactions of four organolithium reagents to 2,3,4,5-tetraphenylcyclopentadienone （tetracyclone） were investigated to reveal the reactivity of organolithium reagents to tetracyclone. The results show that 1,2-addition products 2,3,4,5-tetraphenyl-1-（2-thienyl）-2,4-cyclopentadien-l-ol（1）, 1-n-butyl-2,3,4,5-tetraphenyl- 2,4-cyclopentadien-l-ol（2） and 1,2,3,4,5-pentaphenyl-2,4-cyclopentadien-1-ol（3） were synthesized in excellent yields while tetracyclone reacted with 2-thienyllithium, n-butyllithium and phenyllithium, respectively. Interestingly, three 1,2-, 1,4- and 1,6-addition isomers 1-tert-butyl-2,3,4,5-tetraphenyl-2,4-cyclopentadien-1-ol（4）, 4-tert-butyl-2,3,4,5- tetraphenyl-2-cyclopenten-1-one（5） and 2-tert-butyl-2,3,4,5-tetraphenyl-3-cyclopenten-1-one（6）, were simultaneously obtained by the conjugate addition reaction of tert-butyllithium with larger steric hindrance to tetracyclone. Compounds 1-6 were characterized by ^1H and ^13C NMR spectra, Fourier transform infrared（FTIR） spectra and mass spectra（MS）. The crystal and molecular structures of compounds 1, 2 and isomers 5, 6 were determined by X-ray single crystal diffraction technique. The results imply that the steric hindrance of tert-butyllithium probably play a key role in controlling the conjugate addition reaction. The conjugate addition mechanism of organolithium reagents to tetracyclone was proposed.

关 键 词：Conjugate addition reaction 2 3 4 5-Tetraphenylcyclopentadienone Organolithium reagent Steric hindrance 

分 类 号：O623.22[理学—有机化学] O614.121[理学—化学]