重氮膦酸酯研究进展

重氮化合物是一类重要的卡宾前体,在有机合成中应用广泛。重氮膦酸酯是含磷重氮化合物,与重氮羧酸酯相比,重氮膦酸酯具有一些特殊的反应类型和反应性质。由于重氮膦酸酯具有丰富的化学转化形式以及含磷功能化合物潜在的生物和药物活性,近年来其合成方法以及反应性质成为化学家们的研究热点。本文综述了近年来重氮膦酸酯的研究和应用进展。     

Ionic‐Liquid‐Supported (ILS) Catalysts for Asymmetric Organic Synthesis

The asymmetric synthesis of compounds that contain new C? C and C? O bonds remains one of the most important types of synthesis in organic chemistry. Over the years, many different types of catalysts have been designed and used effectively to carry out such transformations. Ionic‐liquid‐supported (ILS) catalysts represent a new and very effective class of catalysts that are used to facilitate the asymmetric synthesis of such compounds. There are many advantages to using ILS catalysts; they are nontoxic, environmentally benign, and, most important, recyclable. An overview of the design, synthesis, mode of action, and effectiveness of this class of catalysts is reported.     

Catalytic Carbonylation and Carboxylation of Organosulfur Compounds via C−S Cleavage

Transition‐metal‐catalyzed carbonylation with CO gas occupies a privileged position in organic synthesis for the synthesis of carbonyl compounds. Although this attractive and useful chemistry has led many researchers to investigate carbonylative transformations of various organic (pseudo)halides, C?S‐cleaving carbonylation of organosulfur compounds has been fairly limited. Recently, a broad spectrum of C?S‐cleaving transformations has been emerging in the field of cross‐coupling. In light of the importance of carbonyl compounds as well as considerable advancement for employing organosulfur compounds as competent surrogates of (pseudo)halides, carbonylative transformations of C?S bonds should be of high value. This Minireview focuses on catalytic C?S carbonylation of organosulfur compounds with CO or its equivalents. In addition, reductive carboxylation of C?S bonds with CO₂ is described.     

Neutral and Anionic Diboron Compounds Bearing Electron-Precise B−B Bond

Electron-precise B−B bonded compounds are valuable reagents in organic syntheses, which can be used as key starting material for the synthesis of functionalized organoboranes. Bis(pinacolato)diborane(4) B₂pin₂ and its derivatives are among the most studied diboron species. However, their B−B bonds usually need to be activated by transition metal catalysts or bases for further transformations. Recently, many well-designed/reactive electron-precise B−B bonded compounds have been developed, which could facilitate direct reactions with small molecules, unsaturated substrates, and electrophiles. This review highlights the synthesis, structure, and reactivity of neutral and anionic B−B bonded compounds.     

Recent advances on deoximation: From stoichiometric reaction to catalytic reaction

Recent advances on the deoximation reactions are reviewed in this review. It was shown that catalytic deoximation with molecular oxygen as the mild oxidant should be the developing trend of the reaction.     

Selective α-bromination of aryl carbonyl compounds: prospects and challenges

The α-bromination of carbonyl compounds is one of the most important transformations and also important precursors in synthetic organic chemistry. Particularly, the side chain monobromination of carbonyl compounds has been a challenging task, because during the reaction a small amount of disubstituted or ring brominated products as an impurity is always accompanied with monosubstituted product in the reaction mixture. In recent years substantial advances have been made for the synthesis of brominated aromatic carbonyl compounds with high selectivity. In this review, we have summarized various methods for the synthesis of α-bromo aromatic carbonyl compounds.     

锰配合物催化加氢反应的研究进展

过渡金属催化不饱和有机化合物的加氢反应具有原子经济性高、绿色环保等优点,一直是有机化学研究的重点和难点.当前加氢反应中最常用的催化剂主要是铑、钌、铱、钯等贵金属,以储量丰富的金属锰作为催化剂更符合可持续发展的要求,在过去的几年中,锰催化的醛、酮、酯、腈、酰胺等不饱和化合物的氢化反应得以实现.我们系统地总结了锰配合物在加...     

流动化学在卤化反应中的应用

有机物的卤化反应是有机合成中最重要的转化之一.传统釜式卤化反应存在高放热及选择性差等问题,且卤化试剂一般具有毒性和腐蚀性.流动化学在传质和传热方面具有显著优势,可精确控制反应温度及试剂用量,并且可在线淬灭危险试剂,避免其暴露.按有机化合物卤化反应分类,系统地归纳了流动化学在氟化反应、氯化反应、溴化反应和碘化反应中的应用进展,并展望了其发展趋势.     

Micron-particulate crystalline hexagonal aluminium nitride: a novel, efficient and versatile heterogeneous catalyst for the synthesis of some heterocyclic compounds

The present work reports the application of micron-particulate crystalline hexagonal aluminium nitride/aluminium as a novel, mild acidic and reusable solid heterogeneous catalyst in organic synthesis. The catalyst was synthesized by thermal plasma technique and characterized using X-ray diffractometer and scanning electron microscopy. It catalyzes efficiently many organic transformations such as the synthesis of heterocyclic compounds 2,4,5-triaryl-substituted imidazoles and 2-aryl benzimidazoles.     

Construction of Quaternary Stereocenters by Palladium‐Catalyzed Carbopalladation‐Initiated Cascade Reactions

The enantioselective synthesis of molecules containing quaternary stereocenters is a field of intense research interest and development. Among the known organic transformations, carbopalladation‐initiated domino transformations constitutes a general method for the construction of compounds containing cyclic or spiro quaternary stereocenters. In this Minireview, recent achievements in palladium‐catalyzed domino Heck/C?H functionalizations and developments in enantioselective carbopalladation‐initiated domino processes are summarized.     

Chiral-at-metal complexes and their catalytic applications in organic synthesis

This tutorial review provides an introduction to the synthesis and characterization of chiral-at-metal complexes and their catalytic application in organic transformations. The synthetic access to these architectures either via chiral resolution or by employment of chiral ligands is described, characterization techniques for the complexes are referenced and the application of the R/S nomenclature is explained. Racemization and epimerization processes are often observed for the title compounds; the article gives mechanistic insights to these processes and describes how to recognize and document them. Finally, key catalytic applications in organic synthesis are presented and how the molecular architectures of the chiral-at-metal complexes lead to stereodifferentiation and, thus to enantiomeric excesses in the products.     

Light opens a new window for N-heterocyclic carbene catalysis

N-Heterocyclic carbenes (NHCs) are efficient Lewis basic catalysts for the umpolung of various polarized unsaturated compounds usually including aldehydes, imines, acyl chlorides and activated esters. NHC catalysis involving electron pair transfer steps has been extensively studied; however, NHC catalysis through single-electron transfer (SET) processes, despite having the potential to achieve chemical transformations of inert chemical bonds and using green reagents, has long been a challenging task in organic synthesis. In parallel, visible-light-induced photocatalysis and photoexcitation have been established as powerful tools to facilitate sustainable organic synthesis, as they enable the generation of various reactive radical intermediates under extremely mild conditions. Recently, a number of elegant visible-light-induced, NHC-catalyzed transformations were developed for accessing valuable organic compounds. As a result, this minireview will highlight the recent advances in this field.

This minireview summarized the recent advances on the photoinduced, NHC-catalyzed organic reactions according to the function of visible light.     

Transformations based on ring-opening of gem-difluorocyclopropanes

gem-Difluorocyclopropanes are an important fluorinated class of compounds with applications in medicinal chemistry, material sciences and organic synthesis. The transformations based on their ring-opening reactions have been recognized to be useful methods for rapidly synthesizing various fluorinated organic molecules. In this digest paper, we describe these efforts and highlight their powerfully potential and applications as fluorine-containing synthons in organic chemistry.     

From a Si3‐Cyclopropene to a Si3S‐Bicyclo[1.1.0]butane to a Si3S‐Cyclopropene to a Si3S2‐Bicyclo[1.1.0]butane: Back‐and‐Forth,and In‐Between

Compact and highly reactive bicyclo[1.1.0]butanes constitute one of the most fascinating classes of organic compounds. Furthermore, interplay of bicyclo[1.1.0]butanes with their valence isomers, such as buta‐1,3‐dienes and cyclobutenes, is among the fundamental pericyclic transformations in organic chemistry. Herein we report the back‐and‐forth interconversion between the cyclotrisilenes and thiatrisilabicyclo[1.1.0]butanes, allowing for the synthesis of novel representatives of such classes of highly reactive organometallics. The peculiar structural and bonding features of the newly synthesized compounds, as well as the mechanism of their isomerization, were verified both experimentally and computationally.     

From a Si3‐Cyclopropene to a Si3S‐Bicyclo[1.1.0]butane to a Si3S‐Cyclopropene to a Si3S2‐Bicyclo[1.1.0]butane: Back‐and‐Forth,and In‐Between

Compact and highly reactive bicyclo[1.1.0]butanes constitute one of the most fascinating classes of organic compounds. Furthermore, interplay of bicyclo[1.1.0]butanes with their valence isomers, such as buta‐1,3‐dienes and cyclobutenes, is among the fundamental pericyclic transformations in organic chemistry. Herein we report the back‐and‐forth interconversion between the cyclotrisilenes and thiatrisilabicyclo[1.1.0]butanes, allowing for the synthesis of novel representatives of such classes of highly reactive organometallics. The peculiar structural and bonding features of the newly synthesized compounds, as well as the mechanism of their isomerization, were verified both experimentally and computationally.     

Alkenyl Boronates: Synthesis and Applications

Organoboron compounds have become one of the most versatile building blocks in organic synthesis owing to their accessible and efficient conversion into many different functional groups. In particular, alkenyl boronates have received a great deal of attention as very reactive substrates in Suzuki–Miyaura cross‐coupling reactions. Accordingly, efforts towards the development of efficient methods to prepare this type of compound are ongoing. In this contribution, the progress in the search for synthetic routes for alkenyl boronates and their use in a variety of organic transformations is accounted.     

A review of enantioselective dual transition metal/photoredox catalysis

Transition metal catalysis is one of the most important tools to construct carbon-carbon and carbon-heteroatom bonds in modern organic synthesis. Visible-light photoredox catalysis has recently drawn considerable attention of the scientific community owing to its unique activation modes and significance for the green synthesis. The merger of photoredox catalysis with transition metal catalysts, termed metallaphotoredox catalysis, has become a popular strategy for expanding the synthetic utility of visiblelight photocatalysis. This strategy has led to the discovery of novel asymmetric transformations, which are unfeasible or not easily accessible by a single catalytic system. This contemporary area of organic chemistry holds promise for the development of economical and environmentally friendly methods for the asymmetric synthesis of chiral compounds. In this review, the advances in the enantioselective metallaphotoredox catalysis(EMPC) are summarized.     

Electrochemical dehydrogenative N–H/N–H coupling reactions

The N–N bond is present in many important organic compounds, such as hydrazines, pyrazoles, azos, etc. Many methods based on transition metal catalyzed N–N coupling or functionalization of hydrazine have been reported for the synthesis of N–N containing organic compounds. In recent years, electrochemical dehydrogenative N–H/N–H coupling has become a powerful tool for the construction of N–N bearing organic compounds. The electrochemical methods employ electrons as traceless redox reagents instead of chemicals and produce hydrogen as the only byproduct. In this review, we summarize the recent advances in the electrochemical dehydrogenative N–H/N–H coupling reactions with focus on the mechanistic insights and synthetic applications of these transformations.     

Asymmetric electrosynthesis: Recent advances in catalytic transformations

Asymmetric synthesis is one of the most important and valuable research fields in modern organic chemistry. Since the use of electricity as a traceless oxidant or reductant under electrochemical conditions, highly reactive intermediates can selectively generate under mild reaction conditions through more environmentally benign conditions compared with the reactions using common chemical oxidants or reductants. Thus, the merging electrochemistry with asymmetric catalysis would provide a unique and powerful approach for the synthesis of optically active compounds under oxidative or reductive conditions. Selected recent (2018–2020) examples of enantioselective electro-organic synthesis using transition metal catalysts or organocatalysts are summarized in this short review. These examples are divided to oxidative and reductive transformations and described together with brief reaction mechanisms.     

Application of carbene chemistry in the synthesis of organofluorine compounds

The methods for the synthesis of fluorine-containing organic compounds are highly demanded due to the importance of those compounds in various fields. On the other hand, carbenes are in general highly reactive species, though which various transformations are possible. Carbene chemistry has been recently explored in the development of new methodologies for the synthesis of organofluorine compounds. This short report summarizes the recent advances in this area.