Nitrene transfer reactions are powerful tools in synthetic organic chemistry.In recent years,transitionmetal catalyzed nitrene transfer reactions with carbamates as the nitrene precursors have been widely pursued.Such...Nitrene transfer reactions are powerful tools in synthetic organic chemistry.In recent years,transitionmetal catalyzed nitrene transfer reactions with carbamates as the nitrene precursors have been widely pursued.Such species undergoes facile C-H amination,aziridination,and bifunctionalization of alkenes under the catalysis of different transition metals including Rh,Fe,Ru and others,enabling the efficient construction of various nitrogen-containing molecules.In this review,the recent developments in nitrene transfer reactions with carbamates via N-O bond cleavage were introduced based on different types of reaction,and the key mechanistic information and synthetic applications of the methodologies were discussed.展开更多
There is a close relationship between the biological functions of lipids and their structures, and various isomers greatly increases the complexity of lipid structures. The C=C bond location and sn-position are two of...There is a close relationship between the biological functions of lipids and their structures, and various isomers greatly increases the complexity of lipid structures. The C=C bond location and sn-position are two of the essential attributes that determine the structures of unsaturated lipids. However, simultaneous identification of both attributes remains challenging. Here, we develop a visible-light-activated aziridination reaction system, which enables the dual-resolving of the C=C bond location and sn-position isomerism of in lipids when combines with liquid chromatography-mass spectrometry(LC-MS). Based on the derivatization of C=C bonds with Ph I=NTs, their location in lipids could be easily identified by tandem MS. Especially, the sn-position isomers of unsaturated phosphatidylcholine(PC) can be separated and quantified by LC-MS after the derivatization. By using the proposed method, the significant changes of the sn-position isomers ratios of PC in mouse brain ischemia were revealed. This study offers a powerful tool for deep lipid structural biology.展开更多
The urea-catalyzed aziridination of 1,2-vicinal haloamines derived from aminohalogenation of olefins has been developed. This rapid and simple method was carried out by simply grinding the solid mixture of the substra...The urea-catalyzed aziridination of 1,2-vicinal haloamines derived from aminohalogenation of olefins has been developed. This rapid and simple method was carried out by simply grinding the solid mixture of the substrate, K2CO3 and catalytic amount of urea at room temperature in air. The reaction provides a protocol for quantitative preparation of aziridines in a large scope of aminohalogenated derivatives of olefins including α,β-unsaturated ketones, α,β-unsaturated esters and simple olefins. The possible mechanism involving an H-bond promoting deprotonation has been suggested for this reaction.展开更多
Ammonia(NH3)is an ideal nitrogen source in terms of availability,reactivity,safety,atom economy,environmental compatibility,and ease of isolation.However,its utility for amine synthesis is limited by its high bond dis...Ammonia(NH3)is an ideal nitrogen source in terms of availability,reactivity,safety,atom economy,environmental compatibility,and ease of isolation.However,its utility for amine synthesis is limited by its high bond dissociation energy,its strong coordination ability,and the difference between its reactivity and that of the product amines.Herein,we reported the first electrochemical protocol for direct syntheses of unprotected tetrasubstituted aziridines with NH3 and alkenes in the absence of an oxidant,which are highly challenging to achieve by other methods.The combination of graphite felt as the anode material and MeOH as the solvent was the key to the success of the protocol,and the effects of these factors were investigated by means of cyclic voltammetry and density functional theory calculations.展开更多
基金the financial support provided by the National Natural Science Foundation of China(Nos.21572163 and 21873074)the Wenzhou Science&Technology Bureau(No.G20210032)。
文摘Nitrene transfer reactions are powerful tools in synthetic organic chemistry.In recent years,transitionmetal catalyzed nitrene transfer reactions with carbamates as the nitrene precursors have been widely pursued.Such species undergoes facile C-H amination,aziridination,and bifunctionalization of alkenes under the catalysis of different transition metals including Rh,Fe,Ru and others,enabling the efficient construction of various nitrogen-containing molecules.In this review,the recent developments in nitrene transfer reactions with carbamates via N-O bond cleavage were introduced based on different types of reaction,and the key mechanistic information and synthetic applications of the methodologies were discussed.
基金financially supported by the National Natural Science Foundation of China (Nos.22074111, 22004093 and 22004092)the National Key Research and Development Program of China (No.2021YFC2700700)the support of the start-up funds of Wuhan University and the National Youth Talents Plan of China。
文摘There is a close relationship between the biological functions of lipids and their structures, and various isomers greatly increases the complexity of lipid structures. The C=C bond location and sn-position are two of the essential attributes that determine the structures of unsaturated lipids. However, simultaneous identification of both attributes remains challenging. Here, we develop a visible-light-activated aziridination reaction system, which enables the dual-resolving of the C=C bond location and sn-position isomerism of in lipids when combines with liquid chromatography-mass spectrometry(LC-MS). Based on the derivatization of C=C bonds with Ph I=NTs, their location in lipids could be easily identified by tandem MS. Especially, the sn-position isomers of unsaturated phosphatidylcholine(PC) can be separated and quantified by LC-MS after the derivatization. By using the proposed method, the significant changes of the sn-position isomers ratios of PC in mouse brain ischemia were revealed. This study offers a powerful tool for deep lipid structural biology.
基金The authors are grateful to the National Natural Science Foundation of China （No. 20572066）, the Natural Science Foundation of Shaanxi Province （No. 2009JM2011）, and the Innovation Foundation of Postgraduate Cultivation of Shaanxi Normal University （No. 2008CXB009）.
文摘The urea-catalyzed aziridination of 1,2-vicinal haloamines derived from aminohalogenation of olefins has been developed. This rapid and simple method was carried out by simply grinding the solid mixture of the substrate, K2CO3 and catalytic amount of urea at room temperature in air. The reaction provides a protocol for quantitative preparation of aziridines in a large scope of aminohalogenated derivatives of olefins including α,β-unsaturated ketones, α,β-unsaturated esters and simple olefins. The possible mechanism involving an H-bond promoting deprotonation has been suggested for this reaction.
基金supported by the National Natural Science Foundation of China(nos.22071105,22031008,21803030,and 22001089)QingLan Project of Jiangsu Education Department,and the Jiangsu Innovation&Entrepreneurship Talents Plan in China.J.L.appreciates the support from the Nature Science Foundation of Jiangsu Province(no.BK20191046).
文摘Ammonia(NH3)is an ideal nitrogen source in terms of availability,reactivity,safety,atom economy,environmental compatibility,and ease of isolation.However,its utility for amine synthesis is limited by its high bond dissociation energy,its strong coordination ability,and the difference between its reactivity and that of the product amines.Herein,we reported the first electrochemical protocol for direct syntheses of unprotected tetrasubstituted aziridines with NH3 and alkenes in the absence of an oxidant,which are highly challenging to achieve by other methods.The combination of graphite felt as the anode material and MeOH as the solvent was the key to the success of the protocol,and the effects of these factors were investigated by means of cyclic voltammetry and density functional theory calculations.
