A series of novel axially chiral 2,2＇-bipyridine N,N＇-dioxides bearing C1 or C2-symmetry have been synthesized by the use of enantiopure a-amino acids as chiral sources. The absolute stereochemistry of the axial chi...A series of novel axially chiral 2,2＇-bipyridine N,N＇-dioxides bearing C1 or C2-symmetry have been synthesized by the use of enantiopure a-amino acids as chiral sources. The absolute stereochemistry of the axial chirality of these organocatalysts has been clearly assigned by means of CD measurements together with literature protocols. The reactivities and enantioselectivities of these organocatalysts have been examined in the reactions of aromatic aldehydes with allyltrichlorosilane, thus providing the desired products with moderate yields and enantioselectivies.展开更多
A new one-dimensional mixed-valence Cu（Ⅰ）/Cu（Ⅱ） complex [Cu（bipy）（Me2dtc）CuI2]n 1 （bipy = 2,2′-bipyridine and Me2dtc = N,N-dimethyldithiocarbamate） has been synthesized under solution condition, and chara...A new one-dimensional mixed-valence Cu（Ⅰ）/Cu（Ⅱ） complex [Cu（bipy）（Me2dtc）CuI2]n 1 （bipy = 2,2′-bipyridine and Me2dtc = N,N-dimethyldithiocarbamate） has been synthesized under solution condition, and characterized by elemental analysis, IR spectrum, single-crystal X-ray diffraction and magnetic property. The crystal belongs to the tetragonal system, space group P4122 with a = b = 11.6504（16）, c = 13.466（3） A, V = 1827.8（5） A^3, Z = 4, Dc = 2.389 g/cm^3, Mr = 657.27, λ（MoKa） = 0.71073 , μ = 5.931 mm·1, F（000） = 1236, the final R = 0.0483 and wR = 0.1245. A total of 2102 unique reflections were collected, of which 2009 with I 〉 2σ（I） were observed. 1 consists of polymeric [Cu^II2]nn^- anions and [Cu^II（bipy）（Me2dtc）]^＋ cations. It is interesting that the cations of 1 interact through π-π stacking interactions after rotating 90° to form one-dimensional chains parallel to the anion chains. The magnetic study indicates antiferromagnetic behavior for this complex.展开更多
基金We thank Beijing Municipal Commission of Edu- cation （No. JC015001200902）, Beijing Municipal Natu- ral Science Foundation （Nos. 710201, 2122008）, Basic Research Foundation of Beijing University of Technol- ogy （X40 15001201101）, Funding Project for Academic Human Resources Development in Institutions ofHigher Learning Under the Jurisdiction of Beijing Municipality （No. PHR201008025）, Doctoral Scientific Research Start-up Foundation of Beijing University of Technology （No. 52015001200701） for financial sup- ports.
文摘A series of novel axially chiral 2,2＇-bipyridine N,N＇-dioxides bearing C1 or C2-symmetry have been synthesized by the use of enantiopure a-amino acids as chiral sources. The absolute stereochemistry of the axial chirality of these organocatalysts has been clearly assigned by means of CD measurements together with literature protocols. The reactivities and enantioselectivities of these organocatalysts have been examined in the reactions of aromatic aldehydes with allyltrichlorosilane, thus providing the desired products with moderate yields and enantioselectivies.
基金Supported by the National High Technology Research and Development Program of China (863 Program, No. 2009AA03Z217)the National Natural Science Foundation of China (No. 90922028)+1 种基金the Young Talent Program of Fujian Province (No. 2007F3060)the Fund of Fujian Provincial Key Laboratory of Nanomaterials (No. NM10-5)
文摘A new one-dimensional mixed-valence Cu（Ⅰ）/Cu（Ⅱ） complex [Cu（bipy）（Me2dtc）CuI2]n 1 （bipy = 2,2′-bipyridine and Me2dtc = N,N-dimethyldithiocarbamate） has been synthesized under solution condition, and characterized by elemental analysis, IR spectrum, single-crystal X-ray diffraction and magnetic property. The crystal belongs to the tetragonal system, space group P4122 with a = b = 11.6504（16）, c = 13.466（3） A, V = 1827.8（5） A^3, Z = 4, Dc = 2.389 g/cm^3, Mr = 657.27, λ（MoKa） = 0.71073 , μ = 5.931 mm·1, F（000） = 1236, the final R = 0.0483 and wR = 0.1245. A total of 2102 unique reflections were collected, of which 2009 with I 〉 2σ（I） were observed. 1 consists of polymeric [Cu^II2]nn^- anions and [Cu^II（bipy）（Me2dtc）]^＋ cations. It is interesting that the cations of 1 interact through π-π stacking interactions after rotating 90° to form one-dimensional chains parallel to the anion chains. The magnetic study indicates antiferromagnetic behavior for this complex.
