炔桥联不对称苯基取代双二茂铁衍生物的设计合成和电化学性质

以四苯基环戊二烯酮为起始原料,经过八步连续反应,成功地合成了3个炔桥联不对称五苯基取代双二茂铁衍生物Fc′-C≡C-Fc(1)、Fc′-C≡C-C≡C-Fc(2)和Fc′-C≡C-C≡C-Fc′(3)(Fc′=五苯基二茂铁基,Fc=二茂铁基)。在设计合成双二茂铁衍生物的过程中,首先经过4步反应,制备出已知化合物Fc′-H(4),再连续进行3步反应,分别得到3个中间化合物Fc′-COCH_3(5),Fc′-CCl=CHCHO(6)和Fc′-C≡CH(7),最后利用偶联反应,得到目标化合物1~3。利用X射线单晶衍射和循环伏安法,测定了化合物1、2和5、7的晶体结构,研究了化合物1~7的电化学性质。研究结果表明,分子的C-H…π键相互作用和空间位阻是导致化合物1和2分子中Fc′和Fc基空间排布取向不同的主要原因。当二茂铁的一个环戊二烯环上引入5个苯取代基时,铁中心的氧化还原电位将升高(E_p~a(Fc′-H)=0.658 V,E_p~a(Fc-H)=0.511 V)。与已知化合物Fc-C≡C-Fc(ΔE=0.215 V)和Fc-C≡C-C≡C-Fc(ΔE=0.134 V)相比,化合物1~3的氧化电位差值(ΔE)均有不同程度地提高(ΔE_1=0.236 V;ΔE_2=0.170 V;ΔE_3=0.146 V)。将1与Fc-C≡C-Fc,2与Fc-C≡C-C≡C-Fc和3进行比较发现,当炔桥两端连接不同的基团Fc′和Fc时,其氧化电位差值(ΔE)将明显提高。     

不对称双二茂铁脲衍生物的合成、表征及电子传递性质

以二茂铁为原料,通过多步反应,首先合成了对称的桥联双二茂铁脲(5),再将其与胱胺反应,合成了一种新的不对称桥 联双二茂铁脲衍生物MeOOC-Fc-NH-CO-NH-Fc-CO-NH-(CH₂)₂-S-S-(CH₂)₂-NH₂ (7)(Fc：二茂铁)。对目标产物进行了红外、紫外、¹H NMR和MS表征;由于目标化合物7含有不对称的二茂铁脲这一特殊结构,采用循环伏安(CV)方法对化合物7的电子迁移特性进行了研究。结果表明2个二茂铁之间通过脲键传递电子,从而使2个二茂铁基团可以分别被氧化,它们的氧化电位差ΔE_o^?为181 mV,它们之间的稳定常数Kc为1 145。相对于对称的二茂铁脲(5)(ΔE_o^?=140 mV,K_c=207),这种不对称结构分子中2个二茂铁之间电子间的相互作用增强。     

Fe（C5H4-CH2-Trp-OMe）2的合成、晶体结构及金属离子识别性能

摘要： 以优化的两步一锅反应法合成了生物金属有机化合物Fe（C₅H₄-CH₂-Trp-OMe）₂（FcL）,通过NMR、HRMS及IR等对其结构进行了表征,利用X射线单晶衍射测定了分子结构。循环伏安法研究表明FcL在0.00~0.90 V电位范围内,给出一稳定的、形态良好的氧化还原峰,这归于化合物中Fc/Fc⁺电对的氧化还原过程。电化学金属离子识别研究显示FcL在过渡金属离子Zn²⁺和Cu²⁺的存在下,导致了配体Fc/Fc⁺式量电位的显著阳极移动,其△E^0''对Zn²⁺和Cu²⁺分别为342和335 mV,表明了FcL对Zn²⁺和Cu²⁺具有良好的识别能力。     

(μ-FcC≡CH)Co2(CO)6簇合物羰基取代衍生物的合成和分子结构

The substituted reactions of (μ-FcC≡CH)Co₂(CO)₆ with PPh₃, AsPh₃ and dppm have been studied and three new substituted derivatives have been obtained. The compounds were characterized by elemental analysis, IR, ¹H NMR, MS and X-ray crystallography. They have the following formula: (μ-FcC≡CH)Co₂(CO)_6-nL[n=1, L=PPh₃（2）, AsPh₃（3）; n=2, L=dppm (4)]. The cluster 2 crystallizes in monoclinic, space group P2₁/n, with a=1.342 4(8) nm, b=1.305 4(8) nm, c=1.875 0(9) nm, β=103.084(9)°, V=3.201(3) nm³, Z=4, F(000)=1 480, D_c=1.515 g·cm^-3, μ=15.62 cm^-1; final R indices [I > 2σ(I)]: R₁=0.040 9, ωR₂=0.076 9; S=1.007, Δρ_max=463e·nm^-3, Δρ_min=-395 e·nm^-3. The cluster 3 crystallizes in monoclinic, space group P2₁/n, with a=1.341 0(4) nm, b=1.307 9(4) nm, c=1.912 0(5) nm, β=103.043(5)°, V=3.267(15) nm³, Z=4, F(000)=1 552, D_c=1.574 g·cm^-3, μ=24.87 cm^-1; final R indices[I> 2σ（I）]：R₁=0.0437, ωR₂=0.078 2; S=0.995, Δρ_max=530 e·nm^-3, Δρ_min=-444 e·nm^-3. CCDC: 221860, 2; 221863, 3.     

三个基于3-(2，5-二羧基苯基)-吡啶羧酸的Cu(Ⅱ)、Mn(Ⅱ)配合物的结构及磁性

通过水热法合成了3个新型配位聚合物：[Cu（Hdppa）（H₂O）]_n（1）、{[Cu₂（dppa）（μ₂-OH）（H₂O）]·H₂O}_n（2）和{[Mn₃（dppa）₂（H₂O）₄]·2H₂O}_n（3）,（H₃dppa=3-（2,5-二羧基苯基）-吡啶羧酸）,并对其进行了元素分析、红外光谱、粉末X射线衍射和热重分析表征。X射线单晶衍射分析结果表明：化合物1属于单斜晶系,P2₁/c空间群,a=1.371（2）nm,b=0.805（11）nm,c=1.266（19）nm,β=112.74（3）°,Z=4;化合物2属于三斜晶系,P1空间群,a=0.839（4）nm,b=1.039（5）nm,c=1.110（5）nm,α=98.31°,β=110.630（3）°,γ=111.90（3）°,Z=2;化合物3属于三斜晶系,P1空间群,a=0.881（6）nm,b=0.939（6）nm,c=1.038（7）nm,α=100.29°,β=97.990（10）°,γ=111.13（7）°,Z=1。化合物1以配体Hdppa^2-桥联Cu（Ⅱ）形成一维链状结构;化合物2和3以配体dppa^3-分别桥联Cu（Ⅱ）和Mn（Ⅱ）形成二维层状结构,并进一步通过氢键形成三维超分子结构。变温磁化率研究表明在化合物1和化合物2中存在较强的铁磁耦合作用,其磁交换常数分别为4.44和8.94 cm^-1;而化合物3中Mn（Ⅱ）离子之间存在反铁磁相互作用。     

一些二茂铁苯基亚胺化合物的合成与表征

通过回流对应的二茂铁苯胺和芳香醛的混合物的同样路径合成了一系列新颖的二茂铁苯基亚胺化合物(5~12)。当暴露于空气时化合物5~12稳定,不发生任何分解。所有化合物均用¹H、¹³C NMR,MS,IR,UV-Vis和元素分析表征。还报导了化合物N-(3-bromo-2-hydroxylbenzylidene)-4-ferrocenylimine(10)的单晶结构,其结晶属单斜晶系P2₁/c空间群。     

氰基桥联的Fe(Ⅲ)-Mn(Ⅱ)双金属链的可控组装和磁性作用的调控

基于不同位阻的三氰基构筑单元和双齿配体,合成了2个氰基桥联的Fe（Ⅲ）-Mn（Ⅱ）链状化合物。利用不同的结构扭曲类型调控了它们的磁性相互作用。化合物{[Fe（Ⅲ）（PzTp）（CN）₃][Mn（Ⅱ）（5,5''-dmbpy）₂]ClO₄}_n（1;PzTp=tetrakis（pyrazolyl）borate;5,5''-dmbpy=5,5''-dimethyl-2,2''-bipyridine）显示为左右手螺旋链的一维2,2-CC链状结构并且表现出亚铁磁行为。化合物{[Fe（Ⅲ）（Tp^*）（CN）₃]₂[Mn（Ⅱ）（dpqc）]·CH₃OH·H₂O}_n（2;Tp^*=hydridotris（3,5-dimethylpyrazolyl）borate;dpqc=dipyrido[3,2-a：2'',3''-c]-（6,7,8,9-tetrahydro）phenazine）具有一维4,2-带状的双链结构并且表现出典型的反铁磁性相互作用。     

两个三(2-甲基-2-苯基丙基)锡含N杂环羧酸酯的合成、结构、热稳定性、量子化学及毒性研究

在甲醇中氧化双[三（2-甲基-2-苯基）丙基锡]分别与吡嗪-2-甲酸、吲唑-3-甲酸反应,合成了2个三（2-甲基-2-苯基丙基）锡含N杂环羧酸酯（PhCMe₂CH₂）₃Sn[O₂C（C₄N₂H₃）]（1）和（PhCMe₂CH₂）₃Sn[O₂C（C₇N₂H₅）]（2）。经IR、¹H和¹³CNMR、元素分析和X-射线单晶衍射表征结构。配合物1属单斜晶系,空间群P2₁/n,晶体学参数：a=1.20931（7）nm,b=1.81815（11）nm,c=1.49139（9）nm,β=93.567（3）°,Z=4,V=3.2728（3）nm³,D_c=1.302Mg·m^-3,μ（MoKα）=0.812mm^-1,F（000）=1328,R₁=0.0275,wR₂=0.0670。配合物2属三斜晶系,空间群P1。晶体学参数：a=1.15310（7）nm,b=1.81973（11）nm,c=2.62040（16）nm,α=86.866（2）°,β=87.063（2）°,γ=73.332（2）°,Z=6,V=5.2559（6）nm³,D_c=1.288Mg·m^-3,μ（MoKα）=0.762mm^-1,F（000）=2112,R₁=0.0374,wR₂=0.0925。1和2的中心锡原子均为畸变四面体构型。通过分子间C-H…O和N-H…N氢键作用,配合物2形成环状三聚体结构;两相邻三聚体间,经C-H…π作用进一步扩展成为六聚体。热重分析结果表明,1和2具有良好的热稳定性,分别在210、240℃以下可以稳定存在。毒性测试的初步结果表明,配合物1、2对石螺急性毒性较小,具有较好的环境相容性,且1的毒性低于2和苯丁锡。     

基于柔性双(甲基苯并咪唑)和羧酸配体的Cd(Ⅱ)/Co(Ⅱ)/Zn(Ⅱ)配合物的合成和表征

通过水热或溶剂热合成的方法制备了3个Cd（Ⅱ）/Co（Ⅱ）/Zn（Ⅱ）配位聚合物[Cd（hbmb）_0.5（pta）]_n（1），[Co（hbmb）（1，4-bdc）]_n（2）和{[Zn₂（hbmb）_1.5（bptc）（H₂O）]·0.5hbmb·3H₂O}_n（3）（hbmb=1，1''-（1，6-己烷）双-（2-甲基苯并咪唑），H₂pta=邻羧基苯乙酸，1，4-H₂bdc=1，4-苯二乙酸，H₄bptc=3，3''，4，4''-二苯甲酮四羧酸））。单晶结构解析表明配合物1是一个4-连接的二维平面网络，拓扑符号为（4⁴·6²）。配合物2是一个4-连接的二维褶皱网络，拓扑符号为（4²·6）（4²·6³·8）。配合物3是一个（3，4，4）-连接的三重穿插网络，拓扑符号为（4²·6²·8²）（4·6²）（4·6⁴·8）。其中配合物1属于单斜晶系，空间群为P2₁/c，a=0.758 32（15） nm，b=1.452 8（3） nm，c=1.911 3（5） nm，β=112.26（3）°，Z=4；配合物2属于单斜晶系，空间群为P2₁/n，a=1.090 8（2） nm，b=1.873 1（4） nm，c=1.301 9（3） nm，β=91.09（3）°，Z=4；配合物3属于三斜晶系，空间群为P1，a=1.119 6（2） nm，b=1.481 2（3） nm，c=1.926 6（4） nm，α=89.72（3）°，β=87.65（3）°，γ=68.28（3）°，Z=2。     

价电子能级连接性指数及其应用

价电子能级连接性指数( ^fE)被定义为： ^fE=Σ(m_i·m_j…)^-0.5,m为价电子能级值。其中0、1阶指数公式分别为： ⁰E=Σ(m_i)^-0.5、 ¹E=Σ(m_i·m_j)^-0.5。 ⁰E、 ¹E与化合物的总键能(ΔE)、晶格能(U)、标准生成焓(Δ_fH^?_m)以及非金属氢化物的pKa呈现高度相关性。它们的线性回归方程为：ΔE=-48.0095+1402.9463¹E,r=0.9474, U=-328.0770+1541.9351 ¹E, r=0.9801,-Δ_fH^?_m=-266.9299+1324.6461 ¹E, r=0.9509, pKa=-20.9723+28.1756 ¹E, r=0.98884, pKa=-14.6102-7.835 ⁰E+40.6461 ¹E, R=0.9933。m、^fE具有物理意义明确、计算方法简单等优点,而且预测结果令人满意。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.