碳纳米管的共价修饰

碳纳米管(carbon nanotubes, CNTs)的溶解性和分散性较差是目前制约其广泛应用及在一些有特殊要求的领域(如生物技术)应用的主要原因之一. 对CNTs进行共价修饰是改善其溶解性和分散性的有效方法之一. 目前CNTs的共价修饰主要通过两类反应来实现: 羧基的衍生反应和直接加成反应. 介绍了基于这两种反应的几种共价修饰方法, 比较了各种修饰方法的优缺点及其对CNTs的溶解性和分散性的改善效果.     

稀土金属催化的碳氢官能团化反应

过渡金属催化的碳氢官能团化反应具有原子经济性高、区域选择性好和合成路线简短等优点,近年来得到了化学家们的广泛关注,是当前有机合成化学的热门研究领域之一.近几年来,稀土金属催化剂也逐渐被开发应用于该领域,得到优异的结果,同时也表现出一些独特的催化活性.本文综述了稀土金属络合物催化的碳氢官能团化反应,主要包括C-H烷基化反...     

Ruthenium Catalyzed Intramolecular C−X (X=C,N, O,S) Bond Formation via C−H Functionalization: An Overview

Ruthenium catalyzed C−H activation is well known for its high tolerance towards the functional group and broad applicability in organic synthesis and molecular sciences, with significant applications in pharmaceutical industries, material sciences, and polymer industry. In the last few decades, enormous progress has been observed with ruthenium-catalyzed C−H activation chemistry. Notably, the vast majority of the C−H functionalization known in the literature are intermolecular, although the intramolecular variant provides fascinating new structural facet starting from the simple molecular scaffolds. Intramolecular C−H functionalization is atom economical and step efficient, results in less formation of undesired products which is easy to purify. This has created a lot of interest in organic chemistry in developing new synthetic strategies for such functionalization. The focus of this review is to present the relatively unexplored intramolecular functionalization of C−H bonds into C−X (X=C, N, O, S) bonds utilizing versatile ruthenium catalysts, their scope, and brief mechanistic discussion.     

光/电化学氧化诱导C–H键官能团化

C–H键活化及其官能团化一直被认为是合成化学的圣杯,光/电氧化诱导C–H键官能团化反应为追求更为绿色、原子经济性、步骤经济性更高的现代合成化学提供了新思路.我们借助可见光或电化学氧化诱导策略实现了直接C–H键官能团化,即底物无需预官能团化,无需外加氧化剂,可直接实现碳–碳以及碳–杂键的构建.通过光/电化学氧化诱导策略使得反应在更为温和的条件下进行,能够兼容更多官能团,并且为合成化学提供一条新的途径.近些年,该策略已经应用于不同化学环境C–H官能团化构建多种化学键.本文结合该领域的代表性工作,重点介绍本课题组近些年在光/电氧化诱导C–H键官能团化反应上的研究进展,并对这一领域的前景进行了展望.     

Site‐Selective Late‐Stage Aromatic [18F]Fluorination via Aryl Sulfonium Salts

Site‐selective functionalization of C?H bonds in small complex molecules is a long‐standing challenge in organic chemistry. Herein, we report a broadly applicable and site‐selective aromatic C?H dibenzothiophenylation reaction. The conceptual advantage of this transformation is further demonstrated through the two‐step C?H [¹⁸F]fluorination of a series of marketed small‐molecule drugs.     

Recent Advances on Direct Functionalization of Indoles in Aqueous Media

Indoles and their derivatives have dominated a significant proportion of nitrogen-containing heterocyclic compounds and play an essential role in synthetic and medicinal chemistry, pesticides, and advanced materials. Compared with conventional synthetic strategies, direct functionalization of indoles provides straightforward access to construct diverse indole scaffolds. As we enter an era emphasizing green and sustainable chemistry, utilizing environment-friendly solvents represented by water demonstrates great potential in synthesizing valuable indole derivatives. This review aims to depict the critical aspects of aqueous-mediated indoles functionalization over the past decade and discusses the future challenges and prospects in this fast-growing field. For the convenience of readers, this review is classified into three parts according to the bonding modes (C−C, C−N, and C−S bonds), which focus on the diversity of indole derivatives, the prominent role of water in the chemical process, and the types of catalyst systems and mechanisms. We hope this review can promote the sustainable development of the direct functionalization of indoles and their derivatives and the discovery of novel and practical organic methods in aqueous phase.     

Remote C−H Activation of Quinolines through Copper‐Catalyzed Radical Cross‐Coupling

Achieving site selectivity in carbon–hydrogen (C?H) functionalization reactions is a formidable challenge in organic chemistry. Herein, we report a novel approach to activating remote C?H bonds at the C5 position of 8‐aminoquinoline through copper‐catalyzed sulfonylation under mild conditions. Our strategy shows high conversion efficiency, a broad substrate scope, and good toleration with different functional groups. Furthermore, our mechanistic investigations suggest that a single‐electron‐transfer process plays a vital role in generating sulfonyl radicals and subsequently initiating C?S cross‐coupling. Importantly, our copper‐catalyzed remote functionalization protocol can be expanded for the construction of a variety of chemical bonds, including C?O, C?Br, C?N, C?C, and C?I. These findings provide a fundamental insight into the activation of remote C?H bonds, while offering new possibilities for rational design of drug molecules and optoelectronic materials requiring specific modification of functional groups.     

C―H官能化构建硫醚

硫醚作为一类重要的含硫功能分子,广泛存在于天然产物、药物及有机发光材料中。鉴于硫醚类化合物的重要性,近年来化学家们发展了一系列高效构建硫醚的方法。与传统的有机卤化物/有机硼酸与硫醇交叉偶联的合成方法相比,C―H官能化直接构建硫醚的策略因其步骤经济性、原子经济性备受合成化学家们关注,并取得重要进展。本文根据不同过渡金属进行分类,系统阐述了近年来过渡金属催化/参与C―H官能化或无过渡金属催化C―H官能化构建硫醚这一方向研究进展。     

过渡金属催化的硅烷基C(sp3)–H键活化

有机硅化合物在有机合成、材料化学和药物化学中都有广泛应用.因此,其自身的合成方法学在近年来广受关注.从原子经济性的角度出发,选择性的C(sp³)–H键切断是一种高效经济的合成策略.硅烷基单元在有机化合物中广泛存在,通过对硅烷基中的C(sp³)–H键直接官能团化来合成新的有机硅化合物是一种十分有前景的合成方法.近年来,过渡金属催化的C(sp³)–H键活化成为有机合成研究的热点领域.与肟基、唑啉、吡啶基、酰胺基、羧酸酯基等官能团或是与氧、氮或硫等杂原子相连的C(sp³)–H键的活化研究已有许多报道,但是与硅相邻的C(sp³)–H键活化研究报道很少.本文综述了近年来过渡金属催化的硅烷基C(sp³)–H键切断的研究进展.     

Multipurpose Nature of Rapid Covalent Functionalization on Carbon Nanotubes

In the vast field of functionalization routes to carbon nanoforms, the fulfillment of such critical requirements as quick and nonharsh methods, good dispersibility, introduction of reactive groups, short reaction time, and low cost can be quite challenging. Traditional thermally induced diazonium chemistry on single‐walled carbon nanotubes (SWCNTs) is revisited by using commercial anilines and providing useful insight into the versatility of this approach. Functionalized SWCNTs with multiple controllable features, such as degree (and ratio) of coverage, orthogonalization, doping, and high water dispersibility, are obtained by introducing benzenesulfonic acid and benzylamine moieties. The scenario opens up an avenue to address relevant applications in which most functionalization methods could not be applied in a straightforward way.     

A generalized ligand-exchange strategy enabling sequential surface functionalization of colloidal nanocrystals

The ability to engineer surface properties of nanocrystals (NCs) is important for various applications, as many of the physical and chemical properties of nanoscale materials are strongly affected by the surface chemistry. Here, we report a facile ligand-exchange approach, which enables sequential surface functionalization and phase transfer of colloidal NCs while preserving the NC size and shape. Nitrosonium tetrafluoroborate (NOBF4) is used to replace the original organic ligands attached to the NC surface, stabilizing the NCs in various polar, hydrophilic media such as N,N-dimethylformamide for years, with no observed aggregation or precipitation. This approach is applicable to various NCs (metal oxides, metals, semiconductors, and dielectrics) of different sizes and shapes. The hydrophilic NCs obtained can subsequently be further functionalized using a variety of capping molecules, imparting different surface functionalization to NCs depending on the molecules employed. Our work provides a versatile ligand-exchange strategy for NC surface functionalization and represents an important step toward controllably engineering the surface properties of NCs.     

CH bond functionalization: emerging synthetic tools for natural products and pharmaceuticals

The direct functionalization of C? H bonds in organic compounds has recently emerged as a powerful and ideal method for the formation of carbon–carbon and carbon–heteroatom bonds. This Review provides an overview of C? H bond functionalization strategies for the rapid synthesis of biologically active compounds such as natural products and pharmaceutical targets.     

Late-Stage C(sp2)−H Functionalization: A Powerful Toolkit To Arm Natural Products for In Situ Proteome Profiling?

The comprehensive investigation of target interactions from native cellular environments is of paramount importance for natural products and related bioactive compounds in drug discovery and chemical biology. Current chemoproteomic tools, such as in situ proteome profiling can do so effectively, but rely heavily on “tagged” probes that are accessible through traditional organic synthesis at the reactive sites of a compound, which may often be required for target binding. Late-stage functionalization may resolve such limitations by tagging compounds in a single step at biologically inert C−H bonds. Herein, recent advances in late-stage C(sp²)−H functionalization of (hetero)arenes, which are present in many natural products, are summarized, and new toolkits for more widespread use of such strategies to install natural products with next-generation “minimalist” linkers for in situ proteome profiling are suggested.     

Steering Site-Selectivity in Transition Metal-Catalyzed C−H Bond Functionalization: the Challenge of Benzanilides

Selective C−H bond functionalization catalyzed by metal complexes have completely revolutionized the way in which chemical synthesis is conceived nowadays. Typically, the reactivity of a transition metal catalyst is the key to control the site-, regio- and/or stereo-selectivity of a C−H bond functionalization. Of particular interests are molecules that contain multiple C−H bonds prone to undergo C−H bond activations with very similar bond dissociation energies at different positions. This is the case of benzanilides, relevant chemical motifs that are found in many useful fine chemicals, in which two C−H sites are present in chemically different aromatic fragments. In the last years, it has been found that depending on the metal catalyst and the reaction conditions, the amide motif might behave as a directing group towards the metal-catalyzed C−H bond activation in the benzamide site or in the anilide site. The impact and the consequences of such subtle control of site-selectivity are herein reviewed with important applications in carbon-carbon and carbon-heteroatom bond forming processes. The mechanisms unraveling these unique transformations are discussed in order to provide a better understanding for future developments in the field of site-selective C−H bond functionalization with transition metal catalysts.     

Is click chemistry attractive for separation sciences?

Trends in LC focus on dedicated separation developments spanning different fields of applications ranging from sample preparation to miniaturization. Chromatographic performances result from the porous media, its implantation inside the “column,” and its surface functionalization. Because molecular interactions govern chromatographic phenomena, surface functionalization is still a hot research topic. Besides standard approaches for surface functionalization, the use of new surface chemistry reactions opens new perspectives. Click chemistry belongs to this new class of chemical reactions, characterized by its specificity, compatibility with aqueous media, and high reaction yields. In this frame, we review the use of click chemistry reactions in chromatographic sciences. In a first part, we present click chemistry with a specific focus on its implementation in stationary phases. The use of these new clicked materials is detailed and discussed with respect to the chromatographic mode.     

Reaction of Nitrosonium （NO^＋） with Schiff Bases

The reaction of nitrosonium (NO^ ) with Schiff bases produced diazonium salts and aldehydes in good yield. The reaction is assumed to be an electrophilic reaction of nitrosonium with imines via a four-member ring intermediate.     

Organic-inorganic hybrid mesoporous silicas: functionalization, pore size, and morphology control

Topological design of mesoporous silica materials, pore architecture, pore size, and morphology are currently major issues in areas such as catalytic conversion of bulky molecules, adsorption, host-guest chemistry, etc. In this sense, we discuss the pore size-controlled mesostructure, framework functionalization, and morphology control of organic-inorganic hybrid mesoporous silicas by which we can improve the applicability of mesoporous materials. First, we explain that the sizes of hexagonal- and cubic-type pores in organic-inorganic hybrid mesoporous silicas are well controlled from 24.3 to 98.0 A by the direct micelle-control method using an organosilica precursor and surfactants with different alkyl chain lengths or triblock copolymers as templates and swelling agents incorporated in the formed micelles. Second, we describe that organic-inorganic hybrid mesoporous materials with various functional groups form various external morphologies such as rod, cauliflower, film, rope, spheroid, monolith, and fiber shapes. Third, we discuss that transition metals (Ti and Ru) and rare-earth ions (Eu(3+) and Tb(3+)) are used to modify organic-inorganic hybrid mesoporous silica materials. Such hybrid mesoporous silica materials are expected to be applied as excellent catalysts for organic reactions, photocatalysis, optical devices, etc.     

Molecule-to-metal bonds: electrografting polymers on conducting surfaces.

Electrografting is a powerful and versatile technique for modifying and decorating conducting surfaces with organic matter. Mainly based on the electro-induced polymerization of dissolved electro-active monomers on metallic or semiconducting surfaces, it finds applications in various fields including biocompatibility, protection against corrosion, lubrication, soldering, functionalization, adhesion, and template chemistry. Starting from experimental observations, this Review highlights the mechanism of the formation of covalent metal-carbon bonds by electro-induced processes, together with major applications such as derivatization of conducting surfaces with biomolecules that can be used in biosensing, lubrication of low-level electrical contacts, reversible trapping of ionic waste on reactive electrografted surfaces as an alternative to ion-exchange resins, and localized modification of conducting surfaces, a one-step process providing submicrometer grafted areas and which is used in microelectronics.     

石墨烯衍生物的合成及应用

石墨烯是继富勒烯、碳纳米管之后碳纳米材料研究领域涌现出来的又一颗崭亮新星。表面功能化处理是石墨烯强化其优异的本征性能和赋予其他新颖功能的主要技术途径。近年来,研究者相继开发了一系列石墨烯改性与功能化的技术方法,制备得到了多种结构特异、组成丰富和性能独特的石墨烯衍生物。本文基于该领域研究的最新进展,从石墨烯化学的角度出发,综述了石墨烯主要衍生物的制备方法以及应用途径,其中主要包括石墨烯的加氢与氟化、有机功能化、聚合物对石墨烯的共价与非共价修饰、石墨烯衍生物在生物医药研究领域的应用等,并对目前相关研究领域的发展趋势进行了总结和展望。     

C-H键选择性直接电氧化研究

C-H键是有机化合物中最基本的化学键,C-H键的活化和直接转化避免了反应物的预先官能化,是最终实现烷烃类化合物转化为不同种类有机化合物最直接、高效的转换方式,通过C-H键构建C-X键（X=O、C、N）是非常重要和具有挑战性的研究. C-H键直接电氧化活化过程中以“电子”参与反应,不需要加入额外的催化剂,并可通过选择合适的电极材料、支持电解质、溶剂和反应温度,通过恒电流或者恒电位电解,进行具有特定的反应选择性和区域选择性的C-H键电氧化活化,从而获得含其他活性基团的目标产物.