聚合物基磁性复合微球的研究近况

磁性聚合物微球作为一种新兴起的复合功能材料,由于具有纳米尺寸、超顺磁性、良好的生物相容性、低毒性诸多优点,受到了人们广泛而深入的研究。本文简要介绍了无机磁性粒子的制备方法和磁性聚合物微球的分类,主要对磁性高分子微球的传统制备方法和涌现新方法新技术进行了阐述,并分析了各种制备磁性聚合物微球方法的优缺点及主要影响因素。除此之外,本文也介绍了磁性聚合物微球近年来最新研究成果及应用领域,并对高分子微球未来发展趋势和存在的问题进行了分析。     

磁性高分子微球的制备和应用研究进展

磁性高分子微球是近２０年来研究的一类新型功能材料，在生物医学，细胞学和生物工程等领域有着广泛的应用前景，本文对磁性高分子微球的性质，制备方法及功能经方法作了详细评述，介绍了磁性高分子微球在细胞分离，固定化酶，免疫测定，生物导弹，ＤＮＡ分离及核酸杂交等领域的应用。     

磁性高分子微球用于固定化酶的研究进展：生物材料结构及？…

磁性高分子微球是近２０年来发展起来的一种新型功能高分子材料,并已在生物化工、细胞学、生物医学工程等领域得到了广泛应用。本文主要介绍磁性高分子微球的制备和性质以及在固定化酶中的应用。     

磁性高分子微球用于固定化酶的研究进展生物材料结构及性质的基础研究及其应用于药物的控制释放

磁性高分子微球是近20年来发展起来的一种新型功能高分子材料,并已在生物化工、细胞学、生物医学工程等领域得到了广泛应用。本文主要介绍磁性高分子微球的制备和性质以及在固定化酶中的应用。     

磁性高分子微球用于固定化酶的研究进展

磁性高分子微球是近20年来发展起来的一种新型功能高分子材料,并已在生物化工、细胞学、生物医学工程等领域得到了广泛应用.本文主要介绍磁性高分子微球的制备和性质以及在固定化酶中的应用.     

表面含羧基的交联磁性高分子复合微球的合成

首先用化学共沉淀法制备了Fe3O4纳米微粒,并对其表面进行改性。然后在分散介质水中,以二乙烯基苯(DVB)为交联剂,采用改进的乳液聚合法,制备了磁性Fe3O4为核、苯乙烯和丙烯酸的共聚物为壳的交联复合微球,并利用FT-IR、TEM、XRD和XPS等对其进行表征。结果表明:该复合微球的粒度分布均匀、表面含有一定羧基,为单分散性、表面功能化的交联磁性高分子纳米复合微球。     

磁性微球的制备及研究进展

磁性微球作为一种新型功能材料,在磁性材料、生物工程等领域有着广泛的应用前景。文章对磁性高分子微球的制备方法、性质作了较详细的综述,着重介绍了磁性微球在细胞分离、蛋白质的提纯、固定化酶、靶向给药及核酸的分离等领域的应用。     

磁性明胶微球的制备及表征

生物高分子磁性微球作为性能优异的功能高分子材料在固定化酶、靶向药物、细胞分离和免疫分析等方面显示出强大的生命力。我们曾用凝胶-微乳液法化学剪裁技术制备了明胶包裹的复合磁性微粒,本文用共沉淀法制备磁性Fe3O4微晶作为磁性内核,明胶为包裹材料,     

磁性高分子微球的制备及其应用

对磁性高分子微球的研究现状进行了综述,探讨了目前的各种合成制备方法、结构性能以及影响微球磁性的因素,在此基础上对磁性高分子微球在免疫测定、生物导弹、有机合成、环境/食品微生物检测等领域的最新应用进展以及存在的问题进行了分析,提出了该领域的今后发展方向。     

磁性高分子微球

对磁性高分子微球的研究现状进行了综述,详细探讨了目前常用的各种合成制备方法,并对各种方法的优缺点进行了分析。在此基础上,对磁性高分子微球在细胞分离、有机合成、环境/食品微生物检测等领域的最新应用进展及存在的问题进行了分析,指出了该领域今后的研究方向。     

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.