二氧化碳和胺催化合成甲酰胺反应研究

二氧化碳是碳资源利用的最终形式,也是一种绿色的碳一资源。通过催化化学的方法将二氧化碳转化为高附加值精细化学品是二氧化碳循环利用的有效途径。酰胺类化合物是一类重要的化工原料和溶剂,广泛应用于医药、农药、日用化学品及石油化工等众多领域且需求量巨大。因此,以二氧化碳为羰源,通过高效催化体系的建立实现二氧化碳与胺反应合成甲酰胺具有重要意义。本文分别从催化体系、还原剂和反应机理等角度综述了这一领域近年来的主要研究成果。其中,催化体系可分为贵金属催化剂如Ir、Pd、Pt、Ru、Rh,非贵金属催化剂如Ni、Mo、Cu、Fe、Co、Zn、Al,有机分子催化剂和无催化剂体系,常用的还原剂为H₂,硅烷和硼烷。在此基础上,对不同催化体系的典型反应机理进行了讨论。     

Di-2,7-pyrenidecaphyrin(1.1.0.0.0.1.1.0.0.0) and Its Bis-Organopalladium Complexes: Synthesis and Chiroptical Properties

A non-aromatic expanded carbaporphyrinoid, incorporating two built-in 2,7-pyrenylene moieties was synthesized. The intrinsically labile structure was demonstrated by proton-triggered conformational changes between the figure-of-eight and quasi-Möbius conformers. Upon treatment with Pd(OAc)₂, the reaction produces two bis-Pd^II complexes with distinct coordination modes. Metal coordination serves to fix the macrocyclic frameworks with the net result that both bis-Pd^II complexes could be resolved by high performance liquid chromatography (HPLC) on a chiral stationary phase. The isolated enantiomers showed persistent chiroptical properties as evidenced by the intense response in the circular dichroism (CD) spectra and the record high absorption dissymmetry factors (g_abs of up to 0.038) seen in the near-infrared spectral region. Moreover, the mutual interconversion of these two Pd^II complexes was found to be stereospecific and to favor the more stable isomers under weakly acidic conditions.     

主链含联萘的聚吡啶手性离子探针的合成和性质

合成了一种主链含联二萘基团的聚吡啶类共轭聚合物, 并通过圆二色谱(CD) 和紫外可见光谱(UV-Vis) 研究了其对Cu2+和Pd2+的识别能力, 并初步推测了识别机理.     

酚醛树脂为载体的手性螯合树脂的合成与性能

以交联聚苯乙烯为载体的手性螯合树脂与过渡金属离子形成的络合物作配体交换色谱固定相,可拆分多种DL-氨基酸。但载体疏水性强,氮基酸在色谱过程中传质阻力大,保留时间长;硅胶键合的配体交换色谱手性相亲水性好,但柱容量小。我们通过2-羟基丙撑间隔臂将L-脯氨酸功能基联于球形酚醛树脂上,合成了手性螯合树脂(Ⅰ)。以其铜(Ⅱ)络合物作配体交换色谱固定相,对多种DL-氨基酸呈现拆分活性,且保留时间少于1h。     

Dynamic Stereochemistry of M8Pd6 Supramolecular Cages Based on Metal-Center Lability for Differential Chiral Induction,Resolution, and Recognition

A series of isostructural supramolecular cages with a rhombic dodecahedron shape have been assembled with distinct metal-coordination lability (M₈Pd₆-MOC-16, M=Ru²⁺, Fe²⁺, Ni²⁺, Zn²⁺). The chirality transfer between metal centers generally imposes homochirality on individual cages to enable solvent-dependent spontaneous resolution of Δ₈/Λ₈−M₈Pd₆ enantiomers; however, their distinguishable stereochemical dynamics manifests differential chiral phenomena governed by the cage stability following the order Ru₈Pd₆ > Ni₈Pd₆ > Fe₈Pd₆ > Zn₈Pd₆. The highly labile Zn centers endow the Zn₈Pd₆ cage with conformational flexibility and deformation, enabling intrigue chiral-Δ₈/Λ₈−Zn₈Pd₆ to meso-Δ₄Λ₄−Zn₈Pd₆ transition induced by anions. The cage stabilization effect differs from inert Ru²⁺, metastable Fe²⁺/Ni²⁺, and labile Zn²⁺, resulting in different chiral-guest induction. Strikingly, solvent-mediated host–guest interactions have been revealed for Δ₈/Λ₈−(Ru/Ni/Fe)₈Pd₆ cages to discriminate the chiral recognition of the guests with opposite chirality. These results demonstrate a versatile procedure to control the stereochemistry of metal-organic cages based on the dynamic metal centers, thus providing guidance to maneuver cage chirality at a supramolecular level by virtue of the solvent, anion, and guest to benefit practical applications.     

Novel Chiral PNNP-Ru Complexes:Synthesis and Application in Asymmetric Transfer Hydrogenation of Ketones

The efficient catalytic systems generated in situ from RuCl2(PPh3)3 and chiral ligands N,N-bis[2-(di-o- tolylphosphino)-benzyl]cyclohexane-1,2-diamine(2) were employed for asymmetric transfer hydrogenation of aromatic ketones, giving the corresponding optically active alcohols with high activities(up to 99% conversion) and excellent enantioselectivities(up to 96% e.e.) under mild conditions. The chiral ruthenium(Ⅱ) complex (R,R)-3 has been prepared and characterized by NMR and X-ray crystallography.     

Synthesis,Properties and X-ray Crystal Structures of Nickel(II) Complexes of a Hexaazamacrotetracyclic Ligand

The complexes [N₂(L²)₂(H₂O)₄]Cl₄(1) and [Ni(L²)](ClO₄)₂ [sdot]2H₂O (2) (L = 1,3,10,12,16,19-hexaazatetracyclo [17,3,1,1 ^12.16,0^4.9]tetracosane) have been synthesized and structurally characterized by X-ray crystallography, spectroscopic and cyclic voltammetry. The crystal structure of 1 has a distorted octahedral geometry with two secondary and two tertiary amines of the macrocycle and two water molecules. In 2, the coordination geometry around the nickel atom is square-planar with four nitrogen atoms of the macrocycle. The equilibrium [Ni(L²)]²⁺ + 2H₂O &rlhar2; [Ni(L²)(H₂O)₂]²⁺ has been studied in aqueous solution over a temperature range, yielding Δ H° = -19.0 ± 0.2 kJ mol^-1 and Δ S° = - 56.0 ± 0.4 JK^-1 mol^-1. Cyclic voltammetry of the complexes give two one-electron waves corresponding to Ni(II)/Ni(III) and Ni(II)/Ni(I) processes. The electronic spectra and redox potentials of the complexes are influenced significantly by the geometry.     

新型铕三元配合物的合成及光致和电致发光性能研究

利用氮杂苯并 [9,10 ]菲类中性配体 ,合成了两个新型铕三元配合物Eu(DBM) 3 L1和Eu(DBM) 3 L2 (DBM为二苯甲酰甲烷 ;L1,L2 为氮杂苯并 [9,10 ]菲类中性配体 ) ,以元素分析、红外光谱和紫外光谱对其进行了表征 .两种配合物在固体状态下的发射光谱都表现出较强的三价铕离子的特征发射 ,第二配体对中心离子具有较好的协同敏化发光作用 .以TPD和Gd(DBM) 3 bath (bath =4,7 二苯基 1,10 菲咯啉 )分别作空穴传输材料和电子传输材料 ,以发光配合物和TPD的共蒸镀掺杂作为发光层 ,制备了如下结构的三层器件ITO/TPD( 3 0nm) /Eu(DBM) 3 L1(L2 )∶TPD( 1∶2 ) ( 5 0nm) /Gd(DBM) 3 bath( 3 0nm) /Mg∶Ag ,并研究了器件的光电特性 .结果表明 :这两种配合物具有优良的成膜性和电子传输性 ,而氮杂苯并 [9,10 ]菲类中性配体对提高配合物的电子传输性起着至关重要的作用 .以Eu(DBM) 3 L1和Eu(DBM) 3 L2 作为发光材料制备的器件均具有较低的启亮电压 ( 3V) ,分别在 12V ,5 2mA·cm-2 和 13V ,42mA·cm-2 时获得最大亮度为 14 8cd·m-2 和 110cd·m-2 的纯正红色发光     

Preparation for Supramolecular Complexes of Chiral Diols BDPDD,DMBDPD and BINOL with Some Prochiral Compounds

Interaction between chiral diols BDPDD,DMBDPD and BINOL with prochiral compounds was examined and some new supramolecular complexes were prepared.It was found that these chiral hosts could include prochiral guests,α，β-unsarurated compounds or pinperazinedione derivatives to give inclusion crystals in different molar ratio.Formations of these supramolecular complexes were characterized by the data of IR and ^H NMR spectra.     

Carbon Nitride Nanowire Bundle and Tubes：Solid-state Synthesis,Characterization and Photoluminescent Properties

Graphite-like carbon nitride nanowire bundles were synthesized from melamine via the solid state thermolysis at relatively low temperature(400 °C).Hexagonal carbon nitride tubes were prepared for the first time by heating the nanowire bundles at 550 °C in argon atmosphere.The forming process of tubes and transformation of the molecular structures from s-triazine rings to tri-s-triazine units were analyzed.The blue and yellow-green emission photoluminescent(PL) properties of the products were investigated in...     

手性高烯丙基胺的合成及表征——一个微量不对称合成教学实验

描述了一个以立体化学中非对映选择性为知识重点,以无水无氧操作为操作重点的微量不对称合成实验。(R)-N-叔丁基亚磺酰亚胺在无水无氧环境中,经过锌参与的烯丙基化,在不同的溶剂、添加剂条件下以不同的选择性得到了一对非对映异构体,以较高的产率得到终产物。烷基化反应产物的非对映体比率(dr)通过1H与19FNMR以及手性HPLC确定。总体来说,这一实验所用试剂易得,反应条件温和,速率快,产率高;学生在学习无水无氧操作(Schlenk技术)的同时,还能够熟悉立体化学的基本概念,了解如何通过调节反应溶剂和添加剂实现立体化学结果的逆转,并掌握使用手性HPLC和NMR确定光学活性物质的dr值的方法。     

A Fused [5]Helicene Dimer with a Figure-Eight Topology: Synthesis,Chiral Resolution,and Electronic Properties

Chiral shape-persistent molecular nanocarbons are promising chiroptical materials; their synthesis, however, remains a big challenge. Herein, we report the facile synthesis and chiral resolution of a double-stranded figure-eight carbon nanobelt 1 in which two [5]helicene units are fused together. Two synthetic routes were developed, and, in particular, a strategy involving Suzuki coupling-mediated macrocyclization followed by Bi(OTf)₃-catalyzed cyclization of vinyl ether turned out to be the most efficient. The structure of 1 was confirmed by X-ray crystallographic analysis. The isolated (P,P)- and (M,M)- enantiomers show persistent chiroptical properties with relatively large dissymmetric factors (|g_abs|=5.4×10⁻³ and |g_lum|=1.0×10⁻²), which can be explained by the effective electron delocalization along the fully conjugated belt and the unique D₂ symmetry. 1 exhibits local aromatic character with a dominant structure containing eight Clar's aromatic sextet rings.     

Synthesis,Structures, and Properties of Lanthanide Complexes with Pyrimidine‐2‐carboxylic Acid

Six lanthanide complexes [Ln(pmc)₂NO₃]_n [Hpmc = pyrimidine‐2‐carboxylic acid, Ln = La ( 1 ), Pr ( 2 )], [Ln(pmc)₂(H₂O)₃]NO₃ · H₂O [Ln = Eu ( 3 ), Tb ( 4 ) Dy ( 5 ), Er ( 6 )] were synthesized by the reactions of lanthanide nitrate and pyrimidine‐2‐carboxylic acid in water at room temperature. These complexes were characterized by single‐crystal X‐ray diffraction analysis, elemental analysis, IR, circular dichroism (CD) and fluorescence spectra. Structure analysis shows that complexes 1 and 2 are isostructural with P4₃2₁2 space group, whereas isostructural complexes 3 – 6 belong to the P2₁/c space group. In complexes 1 and 2 , the central metal atoms are coordinated by nitrates and pmc^–, which are self‐assembled to construct a 3D porous network with 6₂.6₂.6₂.6₂.6₂.6₂ (6⁶) topology. In complexes 3 – 6 , H₂O and pmc^– ligands are coordinated and the complexes exhibit a one‐dimensional zigzag chain, which is further expanded into a 3D structure by hydrogen bonding. In addition, the circular dichroism of 1 and 2 proves that the two complexes are both chiral with achiral ligand of Hpmc. Luminescent measurements of compounds 3 – 5 indicate that the characteristic fluorescence of Eu³⁺, Tb³⁺, and Dy³⁺ are observed.     

Ternary Sulfides: Model Compounds for the Correlation of Crystal Structure and Magnetic Properties

Relationships between crystal structure and magnetic properties enable an insight into the nature of the binding of atoms or ions in the solid state. Suitable as model substances are transition metal compounds in which the collective bonds that are generally present are directively degraded by incorporation of diamagnetic cations. This requirement of progressive degradation is met with in sulfides of the general composition A_xM_yS_z, where A ? alkali metal and M ? transition metal.     

新型衍生化β-环糊精键合硅胶手性固定相的合成与性能研究

合成了苯基氨基甲酸酯全衍生化β-环糊精键合硅胶手性固定相.在正相色谱条件下,对系列2-(噻唑基)-α-氨基膦酸酯化合物进行了有效的手性拆分研究.结果表明,所有化合物都得到基线分离,对映异构体选择性α>1.2,为制备型液相色谱的手性拆分提供条件.     

Mixed-Ligand Metal Succinate Complexes with 1,10-Phenanthroline and Ethylenediamine: Synthesis,Characterization, Spectroscopic and Thermal Studies. Crystal Structure of Succinatocobalt(II) Complex with Phenanthroline

The novel mixed-ligand metal succinate (suc) complexes with 1,10-phenanthroline (phen) and ethylenediamine (en) have been synthesized and characterized by elemental analyses, magnetic moments, UV-VIS and IR spectra. Thermal reactivity of the complexes was studied in air using DTA and TG, and decomposition of the complexes resulted in the formation of corresponding metal oxides. The crystal structure of the [Co(suc)(H₂O)(phen)₂]·1.5H_CO·C₄H₁₀O complex was determined by x-ray diffraction. The Co(II) complex crystallizes as a monobutanol solvate. In the complex, the cobalt ion lies on an inversion center and displays a distorted octahedral coordination with one aqua, one suc and two phen ligands. The suc ligand acts as a monodentate ligand through one of the negatively charged O atoms, while phen behaves as N-donor bidentate ligand. The crystal also contains disordered lattice water molecules and the structure is stabilized by extensive hydrogen bonding to form a three-dimensional infinite network.     

Assemblies of 1D and 2D Copper(II) Chiral Coordination Polymers by Salicylaldehyde Schiff Bases: Synthesis,Crystal Structures,and Magnetic Properties

Reaction of CuCl₂ · 2H₂O with chiral Schiff bases and sodium dicyanamide led to the formation of two chiral copper(II) coordination polymers, namely [Cu₄(L¹)₂(dca)₄]_n ( 1 ) and [Cu₂(L²)(μ‐Cl)(dca)(H₂O)]_n · nH₂O ( 2 ) {H₂L¹ = (1R, 3S)‐N′,N′′‐bis[salicylidene]‐1,3‐diamino‐ 1,2,2‐trimethylcyclopentane, H₂L² = (1R, 3S)‐N′,N′′‐bis[3‐ethoxysalicylidene]‐1,3‐diamino‐ 1,2,2‐trimethylcyclopentane, dca = dicyanamide}. Both complexes were structurally characterized by elemental analyses, IR spectroscopy and single‐crystal X‐ray diffraction. Complex 1 exhibits a two‐dimensional polymeric structure formed by single dca bridging tetranuclear Cu₄ units. Complex 2 displays a left‐handed helical chain structure constructed from Cu₂ dimers with single dca bridges. The chirality of 1 and 2 was confirmed by circular dichroism (CD) measurements in solution. Both complexes exhibit strong antiferromagnetic couplings with J = –308(4) cm^–1 for 1 and J = –123(1) cm^–1 for 2 in 2–300 K.     

纳米稀土谷氨酸咪唑三元配合物的合成、表征及抗菌活性研究

合成了6种新型纳米稀土三元配合物。通过元素分析、摩尔电导、红外光谱、紫外光谱、氢谱、碳谱、热重-差热等表征,确定了该类配合物的化学组成为：RE（Glu）3ImCl3·3H2O（RE=La^3＋,Nd^3＋,Er^3＋,Eu^3＋,Y^3＋,Gd^3＋;Glu=L-谷氨酸;Im=咪唑）,TEM电镜测试表明其有一定规则形貌,粒径在30-60 nm。通过抗菌实验对其抑菌效果进行研究,结果表明：6种纳米稀土三元配合物对大肠杆菌、金黄色葡萄球菌和白色念珠菌均有较强的抑制作用（最小抑菌浓度MIC分别约为140,100,250μg·ml^-1）,属于广谱抗菌剂;抗菌效果明显优于非纳米稀土三元配合物、稀土氯化物、L-谷氨酸或咪唑。     

Asymmetric Catalytic Aminoalkylations: New Powerful Methods for the Enantioselective Synthesis of Amino Acid Derivatives,Mannich Bases,and Homoallylic Amines

Modern methodologies such as the design of chiral catalysts using combinatorial techniques play a key role in the development of asymmetric aminoalkylations. Thus, powerful enantioselective syntheses for many attractive target compounds using chiral Lewis acid or base catalysts like 1 or 2 were created.