Functionalized organozinc reagents can easily under 1, 4-addition reaction withunsaturated esters in the presence of catalytic amount of Ni (acac)_2 and tertiary ammes under verymild conditions to give the products in...Functionalized organozinc reagents can easily under 1, 4-addition reaction withunsaturated esters in the presence of catalytic amount of Ni (acac)_2 and tertiary ammes under verymild conditions to give the products in excellent yields.展开更多
Functionalized organozinc reagents can easily conduct 1,4-addition reaction with unsaturated esters in the presence of Cu(OAc)2 and LiCl under very Anld conditions to give the products in excellent yields.
Bovine serum albumin (BSA) was labeled with 9,10-anthraquinone and the photochemical fluorimetric reactivity of the covalently conjugated 9,10-anthraquinone was remarkably improved. The mechanism for the enhancement i...Bovine serum albumin (BSA) was labeled with 9,10-anthraquinone and the photochemical fluorimetric reactivity of the covalently conjugated 9,10-anthraquinone was remarkably improved. The mechanism for the enhancement in the photochemical reactivity of conjugated 9,10-anthraquinone with BSA was discussed.展开更多
The reaction of TbCl_3 with K[2,4-(CH_2)_2C_5H_5] at 0℃ in THF followed by crystalliza- tion at -90℃ led to a pale yellow hexagonal prismatic crystalline product [2,4-[CH_3)_2-η~5-C_5H_5]_(2-) Tb·1/2THF, which...The reaction of TbCl_3 with K[2,4-(CH_2)_2C_5H_5] at 0℃ in THF followed by crystalliza- tion at -90℃ led to a pale yellow hexagonal prismatic crystalline product [2,4-[CH_3)_2-η~5-C_5H_5]_(2-) Tb·1/2THF, which is highly sensitive to air and water and rapidly efflorescent at ambient temper- ature. The single Crystal X-ray diffraction data of the compound have been collected at low tem- perature (-60℃) and the crystal structure has been solved by heavy atom method. It belongs to triclinic system, space group Pl with lattice parameters a=8.477 (?),b=12.583 (?),c=12.858 (?), a=118.08°,β=91.38°,γ=108.75°,V=1120.36 (?)~ 3 and Z=2. Least-squares refinement converged to a final value R=0.043. The compound possesses an idealized G_(2h) symmetry、with three 2,4- dimethylpentadienyl ligands bound to the central terbium atom in a pentahapto mode (η~5). Each unit cell contains two molecules of[2,4-(CH_3)_2-η~5-C_5H_5]_3Tb and one molecule of solvent THF, of which the role in the lattice has been discussed in detail.展开更多
Conjugate addition of indoles to a variety of α,β-unsaturated ketones （chalcones） mediated by a catalytic amount of KHSO4 at room temperature under ultrasonic conditions to afford the corresponding Michael adducts...Conjugate addition of indoles to a variety of α,β-unsaturated ketones （chalcones） mediated by a catalytic amount of KHSO4 at room temperature under ultrasonic conditions to afford the corresponding Michael adducts in good to excellent yields was reported.展开更多
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
文摘Functionalized organozinc reagents can easily under 1, 4-addition reaction withunsaturated esters in the presence of catalytic amount of Ni (acac)_2 and tertiary ammes under verymild conditions to give the products in excellent yields.
文摘Functionalized organozinc reagents can easily conduct 1,4-addition reaction with unsaturated esters in the presence of Cu(OAc)2 and LiCl under very Anld conditions to give the products in excellent yields.
文摘Bovine serum albumin (BSA) was labeled with 9,10-anthraquinone and the photochemical fluorimetric reactivity of the covalently conjugated 9,10-anthraquinone was remarkably improved. The mechanism for the enhancement in the photochemical reactivity of conjugated 9,10-anthraquinone with BSA was discussed.
基金This research was supported by the National Natural Science Foundation of China as an item of major project.
文摘The reaction of TbCl_3 with K[2,4-(CH_2)_2C_5H_5] at 0℃ in THF followed by crystalliza- tion at -90℃ led to a pale yellow hexagonal prismatic crystalline product [2,4-[CH_3)_2-η~5-C_5H_5]_(2-) Tb·1/2THF, which is highly sensitive to air and water and rapidly efflorescent at ambient temper- ature. The single Crystal X-ray diffraction data of the compound have been collected at low tem- perature (-60℃) and the crystal structure has been solved by heavy atom method. It belongs to triclinic system, space group Pl with lattice parameters a=8.477 (?),b=12.583 (?),c=12.858 (?), a=118.08°,β=91.38°,γ=108.75°,V=1120.36 (?)~ 3 and Z=2. Least-squares refinement converged to a final value R=0.043. The compound possesses an idealized G_(2h) symmetry、with three 2,4- dimethylpentadienyl ligands bound to the central terbium atom in a pentahapto mode (η~5). Each unit cell contains two molecules of[2,4-(CH_3)_2-η~5-C_5H_5]_3Tb and one molecule of solvent THF, of which the role in the lattice has been discussed in detail.
基金Project supported by the Natural Science Foundation of Jiangsu Province （No. BK2006048）, the Nature Science Key Basic Research of Jiangsu Province for Higher Education （No. 06KJA15007） and the National Natural Science Foundation of China （Nos. 20472062, 20672079）.
文摘Conjugate addition of indoles to a variety of α,β-unsaturated ketones （chalcones） mediated by a catalytic amount of KHSO4 at room temperature under ultrasonic conditions to afford the corresponding Michael adducts in good to excellent yields was reported.
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.
