N''-(2-羟基-5-甲氧基苯甲基)-4-二甲氨基苯甲酰肼及其氧钒(Ⅴ)配合物:合成、晶体结构和脲酶抑制活性

制备了一个苯甲酰腙化合物N'-(2-羟基-5-甲氧基苯甲基)-4-二甲氨基苯甲酰肼(H₂L)。利用H₂L、乙酰氧肟酸(HAHA)和VO(acac)₂在甲醇中反应得到了配合物[VOL(AHA)]。通过元素分析、红外和紫外光谱,以及单晶X-射线衍射对H₂L和其配合物进行了表征。苯甲酰腙配体作为二价阴离子,利用其酚羟基氧原子、亚胺基氮原子、以及烯醇氧原子与V原子进行配位。乙酰氧肟酸配体利用其羰基氧原子和去质子化的羟基氧原子进行配位。配合物中的V原子为八面体配位构型。测试了H₂L、HAHA和钒配合物的脲酶抑制活性。在浓度为100μmol·L^-1时,钒配合物对幽门螺旋杆菌脲酶的抑制率为63%,其IC₅₀值为45μmol·L^-1。还利用分子对接技术研究了配合物分子与脲酶的作用方式。     

含乙酰氧肟酸配体的席夫碱钒配合物的合成、结构及其抑制幽门螺旋杆菌脲酶研究(英文)

本文合成了2个新的含乙酰氧肟酸配体的席夫碱钒配合物,[VⅢL1(HAHA)](1)和[VⅤOL2(AHA)](2),其中L1为N,N′-二(5-甲基水杨基)乙烷-1,2-二胺的二价阴离子,L2为2-{[2-(2-羟乙基氨基)乙亚胺基]甲基}-6-甲基苯酚的一价阴离子,HAHA和AHA分别为乙酰氧肟酸的一价和二价阴离子,通过物理-化学方法以及单晶X-射线衍射表征了它们的结构。在每个化合物中,V原子都采取八面体配位构型。本文还研究了配合物的热稳定性以及其对幽门螺旋杆菌脲酶的抑制活性。在浓度为100μmol·L-1时,配合物1和2对脲酶的抑制率分别为37.2%和81.5%,其中配合物2的IC50值为21.5μmol·L-1。分子对接研究表明配合物2与脲酶活性中心存在有效的作用力。     

N'-(2-羟基-5-甲氧基苯甲基)-4-二甲氨基苯甲酰肼及其氧钒(V)配合物:合成、晶体结构和脲酶抑制活性

制备了一个苯甲酰腙化合物N'-(2-羟基-5-甲氧基苯甲基)-4-二甲氨基苯甲酰肼(H₂L).利用H₂L、乙酰氧肟酸(HAHA)和VO(acac)₂在甲醇中反应得到了配合物[VOL(AHA)].通过元素分析、红外和紫外光谱,以及单晶X-射线衍射对H₂L和其配合物进行了表征。苯甲酰腙配体作为二价阴离子,利用其酚羟基氧原子、亚胺基氮原子、以及烯醇氧原子与V原子进行配位.乙酰氧肟酸配体利用其羰基氧原子和去质子化的羟基氧原子进行配位.配合物中的V原子为八面体配位构型。测试了H₂L、HAHA和钒配合物的脲酶抑制活性.在浓度为100 μmol·L^-1时,钒配合物对幽门螺旋杆菌脲酶的抑制率为63%,其IC₅₀值为45μmol·L^-1.还利用分子对接技术研究了配合物分子与脲酶的作用方式.     

芳酰腙铜(Ⅱ)和锌(Ⅱ)配合物的合成、晶体结构及抗菌活性

合成了一对结构类似的双核铜和锌配合物,Cu₂(L¹)₂ (1)和[Zn₂(L²)₂(CH₃OH)₂] (2),其中L¹和L²分别是2-溴-N'-(2-羟基-5-甲基苯亚甲基)苯甲酰肼(H₂L¹)和2-氯-N'-(2-羟基-5-甲基苯亚甲基)苯甲酰肼(H₂L²)的二价阴离子,通过元素分析、红外光谱以及单晶X射线衍射表征了它们的结构.配合物1以三斜晶系P1空间群结晶,其晶体学参数:a=0.914 11(6) nm,b=1.180 04(7) nm,c=1.359 36(9) nm,α=101.928(2)°,β=91.399(2)°,γ=107.873(2)°,V=1.359 3(2) nm3,Z=2,R₁=0.054 0,wR₂=0.118 9,GOF=0.970.配合 物2以单斜晶系P21/c空间群结晶,其晶体学参数:a=1.216 97(9) nm,b=1.214 96(9) nm,c=1.212 83(9) nm,β=110.939(1)°,V=1.674 8(2) nm3,Z=2,R₁=0.034 1,wR₂=0.068 9,GOF=1.024.X射线分析表明2个化合物都是中心对称的双核配合物,其中配合物1中的Cu原子是平面正方形配位构型,配合物2中的Zn原子是四方锥配位构型.还通过MTT法研究了这两个配合物的抗细菌(大肠杆菌,金黄色葡萄球菌,枯草芽孢杆菌和铜绿色假单胞菌)和抗真菌(白假丝酵母菌和黑曲霉菌)活性.     

芳酰腙铜(Ⅱ)和锌(Ⅱ)配合物的合成、晶体结构及抗菌活性

合成了一对结构类似的双核铜和锌配合物,Cu₂(L¹)₂(1)和[Zn₂(L²)₂(CH₃OH)₂] (2),其中L¹和L²分别是2-溴-N''-(2-羟基-5-甲基苯亚甲基)苯甲酰肼(H₂L¹)和2-氯-N''-(2-羟基-5-甲基苯亚甲基)苯甲酰肼(H₂L²)的二价阴离子,通过元素分析、红外光谱以及单晶X射线衍射表征了它们的结构。配合物1以三斜晶系P1空间群结晶,其晶体学参数:a=0.91411(6) nm,b=1.18004(7) nm,c=1.35936(9) nm,α=101.928(2)°,β=91.399(2)°,γ=107.873(2)°,V=1.3593(2) nm³,Z=2,R₁=0.0540,wR₂=0.1189,GOF=0.970。配合物2以单斜晶系P2₁/c空间群结晶,其晶体学参数:a=1.21697(9) nm,b=1.21496(9) nm,c=1.21283(9) nm,β=110.939(1)°,V=1.6748(2) nm³,Z=2,R₁=0.0341,wR₂=0.0689,GOF=1.024。X射线分析表明2个化合物都是中心对称的双核配合物,其中配合物1中的Cu原子是平面正方形配位构型,配合物2中的Zn原子是四方锥配位构型。还通过MTT法研究了这两个配合物的抗细菌(大肠杆菌,金黄色葡萄球菌,枯草芽孢杆菌和铜绿色假单胞菌)和抗真菌(白假丝酵母菌和黑曲霉菌)活性。     

双烷氧桥联的双核铜(Ⅱ)Schiff碱配合物的合成及配合行为

通过Salen型双肟配体H₂L¹(H₂L¹=5,5′-二(N,N′-二乙胺)-2,2′-[乙二氧双(氮次甲基)]二酚)与乙酸铜反应,合成了一种双核铜(Ⅱ)配合物[Cu₂(L²)₂](H₂L²=4-(N,N′-二乙胺)水杨醛O-(2-羟乙基)肟),并对其进行了X-射线衍射单晶结构分析。     

三个二羧酸配体配位聚合物的合成、结构表征和荧光性质

以羧酸配体2,2''-（1,4-亚苯基双（亚甲基））双（硫二基）二苯甲酸（H₂L¹）和2,2''-（2,3,5,6-四甲基-1,4-亚苯基）双（亚甲基）双（硫二基）二苯甲酸（H₂L²）分别与金属盐反应,通过溶剂热方法合成了3个配位聚合物：{[Ni（L¹）（H₂O）₄]·2H₂O}_n （1）、[Zn（L¹）（DMA）₂]_n （2）和[Co（L²）（DMF）₂]_n （3）,其中DMA=N,N-二甲基乙酰胺,DMF=N,N-二甲基甲酰胺。对配合物1~3进行了单晶X射线衍射、元素分析、红外光谱、热重分析、粉末X射线衍射和固体紫外可见光谱测试和表征。单晶X射线衍射表明：3个配合物均为一维锯齿形链状结构,并通过氢键作用形成三维骨架,且配体均表现为反式构象。此外,对配合物2固态荧光性质进行了研究。     

三个二羧酸配体配位聚合物的合成、结构表征和荧光性质

以羧酸配体 2,2''-(1,4-亚苯基双(亚苯基))双(硫二基)二苯甲酸(H₂L¹)和 2,2''-(2,3,5,6-四甲基-1,4-亚苯基)双(亚甲基）双(硫二基)二苯甲酸(H₂L²)分别与金属盐反应,通过溶剂热方法合成了 3个配位聚合物：{[Ni(L¹)(H₂O)₄]·2H₂O}_n (1)、[Zn(L¹)(DMA)₂]_n(2)和[Co(L²)(DMF)₂]_n (3),其中DMA=N,N-二甲基乙酰胺,DMF=N,N-二甲基甲酰胺。对配合物1~3进行了单晶X射线衍射、元素分析、红外光谱、热重分析、粉末X射线衍射和固体紫外可见光谱测试和表征。单晶X射线衍射表明：3个配合物均为一维锯齿形链状结构,并通过氢键作用形成三维骨架,且配体均表现为反式构象。此外,对配合物2固态荧光性质进行了研究。     

离子对间电荷转移配合物：阴离子…π作用及近红外吸收

合成并表征了一种离子对配合物1,[Cl₂Bz-1-Apy]₂[Ni(mnt)₂],其中,Cl₂Bz-1-Apy为(E)-1-(3,4-二氯苯亚甲基氨基)吡啶一价阳离子,mnt是马来二睛基二硫烯二价阴离子。在配合物1的晶体中,阴离子和阳离子中吡啶环之间存在阴离子…π相互作用。DFT电荷密度分布分析表明,阴离子…π相互作用主要源自离子对间的Coulomb吸引力。在固体和乙腈溶液电子吸收光谱近红外区,配合物1都有一个宽的弱吸收带,该吸收带可归属为二价阴离子[Ni(mnt)₂]^2-内的d-d电子跃迁和阴阳离子对间的电荷转移跃迁。     

二核双席夫碱铜(Ⅱ)配合物的合成、晶体结构及抗菌活性研究

合成了一对结构类似的双核铜配合物,[CuL¹]₂（1）和[CuL²]₂（2）,其中L¹是双席夫碱配体N,N’-二（5-氟水杨基）-1,3-丙二胺（H₂L¹）的二价阴离子,L²是N,N’-二（5-氟水杨基）-1,2-乙二胺（H₂L²）的二价阴离子,通过元素分析、红外光谱以及单晶X-射线衍射表征了它们的结构。配合物1以单斜晶系P2₁/c空间群结晶,其晶体学参数a=1.3488（1）nm,b=0.6814（1）nm,c=1.7087（1）nm,β=108.903（3）°,V=1.4857（2）nm³,Z=4,R₁=0.0480,wR₂=0.1141,Goof=1.115。配合物2以单斜晶系C2/c空间群结晶,其晶体学参数a=2.7568（2）nm,b=0.7036（1）nm,c=1.4547（1）nm,β=94.758（2）°,V=2.8118（5）nm³,Z=4,R₁=0.0472,wR₂=0.1139,Goof=1.094。X-射线分析表明2个化合物都是中心对称的双核配合物,其中Cu原子都是四方椎配位构型。通过MTT法研究了这2个配合物的抗细菌（枯草芽孢杆菌,金黄色葡萄球菌,大肠杆菌和荧光假单胞菌）和抗真菌（白假丝酵母菌和黑曲霉菌）活性。     

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.     

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.     

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.