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 result...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.展开更多
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）.
文摘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.
