N-环钯化二茂铁衍生物的合成和应用（英文）

近年研究表明二茂铁的环钯化衍生物被广泛地应用于各类偶联反应中,比如Heck反应、Suzuki反应、aza-Claisen重排反应等.主要综述了含氮导向基的二茂铁衍生物的环钯化反应,包括通过不对称诱导或拆分手段合成具有平面手性环钯化合物,基于环金属化反应1,1'-取代二茂铁钯化物的合成,以及其在催化反应的应用.     

过渡金属催化的碳氢键官能团化反应合成平面手性二茂铁化合物

在不对称催化反应中,平面手性二茂铁化合物是一类非常高效的手性配体和催化剂.从原子和步骤经济性方面考虑,与传统方法相比不对称碳氢键直接官能团化反应是构建平面手性二茂铁最简洁有效的方法.综述了铜、钯、铑、铱、金和铂等过渡金属催化的不对称碳氢键官能团化反应合成平面手性二茂铁化合物的最新进展.此外,还介绍了利用这些方法合成多种平面手性二茂铁配体和催化剂及其不对称催化反应.     

1-和1,1'-取代的手性二茂铁Schiff碱的合成及表征

在过去十年中,二茂铁化学不断地发展,丰富,特别是在材料化学,电化学,不对称合成化学中引起了人们的极大兴趣,其应用前景也愈来愈被看好。其中,二茂铁的Ｓｃｈｉｆｆ碱是重要的一类衍生物,可方便地进行环钯化反应和Ｃ=Ｎ双键的加成反应,合成具有良好的光电性能和催化作用的金属有机化合物,所以其发展已受到人们的关注[1]。目前,对它的研究多集中在非手性的衍生物上,通过它们合成高光学纯度的金属有机化合物(如:具有平面手性的环钯化合物等)往往要用具有光学活性的化合物进行拆分[2],方法复杂,不易操作。我们设想,合成带有手性的二茂铁Ｓｃｈ…     

平面手性二茂铁亚胺环钯、环汞化合物与金属锡的 金属转移反应

通过手性二茂铁亚胺环钯化合物(Sp,Sp)-[{Pd[(η^5-C~5H~5)Fe{(η^5-C~5H~3)C(CH~3)＝N-Ar}](μ-Cl)}~2],手性二茂铁亚胺环汞化合物[HgCl{η^5-C~5H~5)Fe(η^5-C~5H~3)C(CH~3)＝N-Ar}]与金属锡的金属转移反应,均得到保持茂环平面手性的手性二茂铁亚胺环锡化合物。产物均经元素分析、IR和^1HNMR鉴定,X射线晶体结构分析确定了有机锡化合物的绝对构型,并经CD谱验证。     

光镍协同催化的不对称还原交叉偶联反应

<正>手性有机磷化合物在不对称金属和有机小分子催化以及手性医药材料研究等领域有着广泛的应用,尤其在不对称催化反应中,手性膦配体发挥着重要作用.传统制备手性有机磷化合物的方法经常从化学计量的手性助剂出发,或通过手性拆分外消旋有机磷化合物.近年来随着不对称催化的快速发展,通过一系列高效的不对称催化反应可以构建手性有机磷化合物,     

手性磷酸控制的不对称碳氢芳基化反应合成平面手性二茂铁化合物

报道了钯催化的分子内不对称C—H键芳基化反应.以简单易得的二茂铁羰基化合物为底物,Pd(CH_3CN)_4(OTf)_2为催化剂,使用手性磷酸作为唯一手性源,Buchwald类型联苯单膦配体,甲苯作溶剂,100℃进行反应,得到一系列二茂铁化合物,ee值最高可达83%.该反应为合成平面手性二茂铁化合物提供了一种新途径.     

亮点介绍

<正>钯催化不对称碳氢键活化构建磷手性中心化合物Angew.Chem.Int.Ed.2015,54,6265~6269含磷手性中心化合物可被用来合成手性膦配体在不对称催化反应中应用,但通常其合成会涉及到拆分或手性柱分离等过程.中国科学院上海有机化学研究所段伟良等对二芳基磷酰溴代苯胺的分子内碳氢活化反应进行了探索,尝试构建含磷手性中心化合物.发现钯催化剂结合酒石酸衍生的亚膦酰胺配体,可以选择性地切断磷上一个芳基的     

胺及其衍生物的非酰基化动力学拆分

光学纯胺在合成与药物化学领域都有着广泛的应用,发展其高效的合成方法一直以来是有机化学界的研究热点.其中通过N酰基化及去酰基化动力学拆分方法获得光学纯胺化合物,已经成为合成手性胺类化合物的重要方法.近年来,基于非酰基化(或去酰基化)的不对称反应实现外消旋胺的动力学拆分的报道不断涌现,包括一些氨基不参与反应的非酰基化(或去酰基化)不对称反应的外消旋胺的动力学拆分.根据氮原子是否参与反应以及反应类型的不同,总结了外消旋胺的化学催化动力学拆分的研究进展.     

过渡金属催化法合成平面手性二茂铁衍生物的新进展

平面手性二茂铁衍生物已经发展成为不对称催化反应中一类良好的手性配体和手性催化剂.高效、高对映选择性的平面手性二茂铁衍生物合成方法研究是不对称催化研究的热点之一.综述了近年来利用过渡金属催化法合成面手性二茂铁衍生物的进展.     

钯配合物与手性方酰胺协同催化的乙烯基碳酸乙烯酯与醛的不对称脱羧环加成反应

利用金属钯与非手性膦配体原位生成的钯配合物和手性方酰胺为协同催化体系实现了乙烯基碳酸乙烯酯（VECs）与甲醛的不对称脱羧环加成反应，以良好的产率和对映选择性得到了手性叔醇类化合物.发现了有机小分子催化剂-手性方酰胺可实现该反应的不对称诱导，为通过两性离子烯丙基钯中间体的环加成反应的研究提供了新的思路.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

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.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

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.