基于V型配体的三个荧光Zn-MOF对水溶液中2，4，6-三硝基苯酚和Fe3+的荧光传感

在溶剂热条件下,合成了3个基于V型配体的Zn(Ⅱ)金属有机骨架：{[Zn₂(BIDPS)₂(OBA)₂]·DMA}_n(1)、{[Zn(BIDPT)(PA)]·DMF}_n(2)和{[Zn(BIDPS)(PA)(H₂O)₂]·2H₂O}_n(3)(BIDPS=4,4''-二(1-咪唑基)苯砜,H₂OBA=4,4''-二苯醚二甲酸,H₂PA=帕莫酸,BIDPT=4,4''-二(1-咪唑基)苯硫醚)。利用X射线单晶衍射、红外光谱、元素分析、热重分析、X射线粉末衍射对其结构进行了表征。配合物1具有二重穿插的三维cds拓扑网络结构。配合物2为二维(4,4)层状结构,层与层之间通过互锁形成2D→3D的三维金属有机骨架。配合物3具有一维链状结构,一维链通过分子内和分子间氢键连接,形成三维超分子结构。荧光研究表明,配合物1~3可以在pH=4~10的水溶液中稳定存在,且在水中具有较强的发光性能,可作为检测2,4,6-三硝基苯酚和Fe³⁺的发光传感器,具有较高的灵敏度和选择性。     

以4，4''-二(1-咪唑基)苯砜或4，4''-二(1-咪唑基)苯硫醚为配体的配位聚合物的合成、晶体结构及性质

通过水热法合成并表征了3个基于V型配体构筑的新颖配位聚合物{[Cd（BIDPS）（PA）（H₂O）]·CH₃OH}_n（1）、{[Zn（BIDPS）（p-bdc）]·H₂O}_n（2）和[Mn（BIDPT）（NBA）]_n（3）（BIDPS=4,4''-二（1-咪唑基）苯砜,H₂PA=帕莫酸,p-H₂bdc=对苯二甲酸,BIDPT=4,4''-二（1-咪唑基）苯硫醚,H₂NBA=4,4''-氮杂二基二苯甲酸）。单晶结构分析表明化合物1和2具有二维网络结构,化合物1进一步通过倾斜穿插形成三维结构,化合物2通过分子间氢键形成了三维网络结构。化合物3属于3-连接六边形的蜂窝状结构,通过C—H …π作用形成三维超分子结构。化合物1和2在水中具有很好的稳定性和荧光性质,可作为高灵敏度、高选择性荧光探针检测水溶液中的Fe³⁺和Cr₂O₇^2-,并能抵抗多种竞争离子的干扰。同时研究了其对Fe³和Cr₂O₇^2-的荧光猝灭机理。     

4, 4''-二(1-咪唑基)苯硫醚及邻苯二甲酸构筑的两个配位聚合物的合成、晶体结构及荧光性质

在温和的水热条件下,以4,4'-二(1-咪唑基)苯硫醚(BIDPT)和邻苯二甲酸(H₂pht)为配体,合成了2个配位聚合物{[Zn(BIDPT)(pht)]₂·2H₂O·CH₃OH}_n(1)和{[Cd₅(BIDPT)₄(pht)₅]·H₂O}_n(2),分别用X-射线单晶衍射、元素分析和IR等手段对它们进行了表征。结果表明,配位聚合物1和2为2D层状结构,配位聚合物1属于正交晶系,Pbcn空间群;配位聚合物2属于三斜晶系,P2₁/c空间群。此外还考察了1和2的热稳定性和固体荧光性质。     

4,4''-二(1-咪唑基)苯硫醚及邻苯二甲酸根构筑的两个配位聚合物的合成、晶体结构及荧光性质

在温和的水热条件下,以4,4'-二(1-咪唑基)苯硫醚(BIDPT)和邻苯二甲酸(H₂pht)为配体,合成了2个配位聚合物{[Zn(BIDPT)(pht)]₂·2H₂O·CH₃OH}_n(1)和{[Cd₅(BIDPT)₄(pht)₅]·H₂O}_n(2),分别用X-射线单晶衍射、元素分析和IR等手段对它们进行了表征。结果表明,配位聚合物1和2为2D层状结构,配位聚合物1属于正交晶系,Pbcn空间群;配位聚合物2属于三斜晶系,P2₁/c空间群。此外还考察了1和2的热稳定性和固体荧光性质。     

基于5-(4-羟基吡啶基甲基)间苯二甲酸配体的两种Zn(Ⅱ)的配位聚合物的合成、结构和荧光性质

采用水热合成的方法,在以5-（4-羟基吡啶基甲基）间苯二甲酸（H₂L）作主配体、4,4''-联吡啶（4,4''-bpy）和1,2-二（4-吡啶基）乙烯（bpe）作辅配体的条件下,得到2种新颖的Zn（Ⅱ）配位聚合物{[Zn（L）（4,4''-bpy）_0.5]·2H₂O}_n（1）和{[Zn（L）（bpe）_0.5]·2H₂O}_n（2）。配合物通过单晶X射线衍射的方法进行了结构分析,并进一步通过红外光谱（IR）、元素分析、PXRD和热重分析（TG）的方法进行了表征。结构分析表明配合物1展现出的是一种三维三重互穿网络;聚合物2为二维双层结构,并进一步组合成了三重平行互穿的2D→3D的空间网络。此外,研究了配合物的荧光性质。     

两种3D微孔Zn-MOF对水溶液中Fe3+、Cr2O72-和丙酮分子的荧光传感

通过溶剂热法合成了2种三维微孔锌金属有机框架材料,其分子式为[Zn₃(DBA)(OH)(1,10-phen)₂]_n(1)和{[Zn₂(HDBA)(4,4''-bipy)_1.5]·H₂O}_n(2)(H₅DBA=3,5-二(2'',4''-对羧基苯基)苯甲酸;1,10-phen=1,10-菲咯啉;4,4''-bipy=4,4''-联吡啶)。结构分析表明,配合物1为三核锌基金属单元的三维微孔骨架,配合物2为双核锌基的微孔结构。与2相比,配合物1在水中具有较强的发光性能,可作为检测Fe³⁺、Cr₂O₇^2-和丙酮分子的发光传感器,具有较高的选择性和灵敏度。     

两个含3，3'-硫代二丙酸配体的锰和铜配合物的合成、晶体结构与性质

使用3,3''-硫代二丙酸、4,4''-联吡啶和硝酸锰在水热条件下反应合成了1个锰配合物,即{[Mn（DPA）（4,4''-bipy）]·H₂O}_n（1）（DPA=3,3''-硫代二丙酸,4,4''-bipy=4,4''-联吡啶）;然后又利用3,3''-硫代二丙酸、1,3-双（4-吡啶基）丙烷和硝酸铜在水热条件下反应合成了1个铜配合物,即{[Cu（DPA）（bpp）（H₂O）]·H₂O}_n（2）（DPA=3,3''-硫代二丙酸,bpp=1,3-双（4-吡啶基）丙烷）。并对它们分别进行了元素分析、红外光谱、热稳定性、X射线粉末衍射和X射线单晶衍射的表征。结果表明：配合物1和2分别由3,3''-硫代二丙酸配体和不同氮杂环分子以及金属离子构筑,形成了二维层状的结构。氢键和π-π作用进一步将二维结构拓展成三维超分子网络。     

三个含4，4'-(吡啶-3，5-二基)二苯甲酸配体的锌(Ⅱ)、镍(Ⅱ)和钴(Ⅱ)配位聚合物的合成、晶体结构及催化性质

采用水热方法,选用4,4''-（吡啶-3,5-二基）二苯甲酸配体（H₂pdba）与菲咯啉（phen）、2,2''-联吡啶（bipy）或2,2''-联咪唑（H₂biim）分别与ZnCl₂、NiCl₂·6H₂O和CoCl₂·6H₂O在160 ℃温度下反应,合成了2个二维层状配位聚合物{[Zn（μ₃-pdba）（phen）]·H₂O}_n （1）和{[Ni（μ₃-pdba）（bipy）]·3H₂O}_n （2）,以及1个具有一维链结构的配位聚合物{[Co（μ₃-pdba）（H₂biim）（H₂O）]·H₂O}_n （3）,并对其结构和催化性质进行了研究。研究表明,在70 ℃条件下配合物1在Henry反应中显示出较好的催化活性。优化了反应参数,对反应底物范围也进行了研究。     

四种同构镧系金属有机框架的合成、结构和荧光传感Fe3+和盐酸环丙沙星

采用溶剂热法,以含氮四羧酸3,5-二(3'',5''-二羧苯)-1H-1,2,4-三唑(H₄BDT)为配体,成功合成了4种同构镧系金属有机框架(Ln-MOFs)：{[La₃(BDT)₂(HCOO)(H₂O)₅]·0.5H₂O·3DMF}_n(1)、{[Ce₃(BDT)₂(HCOO)(H₂O)₅]·3DMF}_n(2)、{[Pr₃(BDT)₂(HCOO)(H₂O)₅]·3DMF}_n(3)和{[Nd₃(BDT)₂(HCOO)(H₂O)₅]·3DMF}_n(4),并采用单晶X射线衍射、粉末X射线衍射、元素分析、热重、傅里叶换红外光谱、N₂吸附实验和荧光光谱对其进行表征。结果表明,这些Ln-MOFs均为单斜C2/m空间群晶体,是双核为无机建筑单元的三维介孔结构。其中2可选择性荧光检测Fe³⁺离子和盐酸环丙沙星药物分子,检测限分别为4.59和0.77 μmol·L^-1。     

三个含4，4′-(吡啶-3，5-二基)二苯甲酸配体的锌(Ⅱ)、镍(Ⅱ)和钴(Ⅱ)配位聚合物的合成、晶体结构及催化性质

采用水热方法，选用 4，4''-(吡啶-3，5-二基)二苯甲酸配体(H₂pdba)与菲咯啉(phen)、2，2''-联吡啶(bipy)或 2，2''-联咪唑(H₂biim)分别与 ZnCl₂、NiCl₂·6H₂O 和 CoCl₂·6H₂O 在 160 ℃温度下反应，合成了 2 个二维层状配位聚合物{[Zn(μ₃-pdba)(phen)]·H₂O}_n (1)和{[Ni(μ₃-pdba)(bipy)]·3H₂O}_n (2)，以及 1个具有一维链结构的配位聚合物{[Co(μ₃-pdba)(H₂biim)(H₂O)]·H₂O}_n (3)，并对其结构和催化性质进行了研究。研究表明，在70 ℃条件下配合物1在Henry反应中显示出较好的催化活性。优化了反应参数，对反应底物范围也进行了研究。     

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.     

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%).     

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.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

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.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.     

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.