Recent Advances in the Synthesis of Heterocycles and Related Substances Based on α‐Imino Rhodium Carbene Complexes Derived from <i>N</i>‐Sulfonyl‐1,2,3‐triazoles

Jiang, Yu; Sun, Run; Tang, Xiang‐Ying; Shi, Min

doi:10.1002/chem.201601703

Cited by 206 publications

(37 citation statements)

References 109 publications

(127 reference statements)

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“…Carbenes are unique species that possess exceptional electronic structures and diverse properties. − These characteristics make carbene complexes highly reactive intermediates and the mechanisms of carbene transformations complicated and intriguing. , The introduction of transition metals could further stabilize the free carbene and tune its reactivity, which enables the carbene chemistry to be more versatile. − For instance, N -heterocyclic carbenes (NHCs) − have emerged as not only powerful catalysts − in organic synthesis but also practical ligands for transition-metal catalysis. − The particular electronic and steric properties of NHC ligands have been widely used to tune the reactivity and selectivity in a range of coupling reactions. ,− In addition, metal carbene insertion into X–H (X = C, N, O, etc.) bonds has been developed as an efficient synthesis strategy. − Remarkable progress has been achieved in this area.…”

Section: Introductionmentioning

confidence: 99%

Recent Advances in Theoretical Studies on Transition-Metal-Catalyzed Carbene Transformations

Lan

2021

Acc. Chem. Res.

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Conspectus Metal carbene plays a vital role in modern organic synthesis. The neutral divalent carbon of metal carbene renders it an active intermediate throughout a range of reactions. In experiments, diverse metal carbene-related transformation reactions have been established, including transition-metal-catalyzed cross-coupling reactions using N-heterocyclic carbenes as ligands, metal carbene insertion into σ bonds, cyclopropanations, ylide formation, and so forth. The remarkable progress achieved in synthetic chemistry, in turn, has increased the demand for mechanistic studies of carbene chemistry. A thorough understanding of reaction mechanisms can extend the application scope of metal carbene compounds and inspire the rational design of new carbene transformation reactions. Density functional theory (DFT) calculations have been performed in our group to gain more mechanistic insights into metal carbene-related reactions. This account focuses on computational studies of transition-metal-catalyzed carbene transformation reactions with nucleophiles. The generation of metal carbene or metal-ligated free carbene and subsequent carbene transformation pathways is discussed. According to our mechanistic studies of carbene transformation with nucleophiles, three generalized reaction models are summarized, including the intramolecular migratory insertion of metal carbene, intermolecular nucleophilic addition toward metal carbene, and outer-sphere nucleophilic addition to the metal-ligated free carbene. In general, the intermolecular nucleophilic addition mechanism is commonly proposed since metal carbene has an electrophilic carbene carbon. From a mechanistic point of view, the intramolecular migratory insertion mechanism is also widely used because metal carbene insertion into σ bonds formally occurs through this mechanism. An outer-sphere nucleophilic addition mechanism is proposed for reactions that form a metal-ligated free carbene complex instead of the commonly proposed metal carbene. The metal-ligated free carbene complex contains a naked carbene carbon that is not coordinated with the metal center. In this case, a transition-metal catalyst is used only as a Lewis acid, and nucleophilic addition occurs directly at the free carbene carbon. Our computational results suggested that outer-sphere nucleophilic addition is a facile step because metal ligation could stabilize the transition state as well as the generated intermediate. The intramolecular migratory insertion mechanism also has a low energy barrier due to the lack of an entropy penalty. Carbene formation from carbene precursors is usually the rate-determining step, except in intermolecular nucleophilic addition, and the reactivity of nucleophiles has a significant influence on the overall reaction rate. We can also envision that the weak nucleophilicity of nucleophiles would suppress outer-sphere nucleophilic addition. These computational studies showcase the characteristics of three carbene transformation models, and we hope that it will spur the developm...

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Section: Introductionmentioning

confidence: 99%

Recent Advances in Theoretical Studies on Transition-Metal-Catalyzed Carbene Transformations

Lan

2021

Acc. Chem. Res.

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“…The components of red pericarp and white pericarp are relatively simple, mainly containing polysiloxane 78 and some heterocyclic substances 79 . Plant‐source polysiloxane is a bioactive organosilicon in recent years.…”

Section: Results and Analysismentioning

confidence: 99%

Constituent diversity of ethanol extracts from pitaya

Zhang

et al. 2020

Asia-Pacific J Chem Eng

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Pitaya is rich in nutrition and unique in function and contains vegetable albumin, anthocyanins, rich vitamins, and water soluble dietary fiber, which are rare in fruits and vegetables. However, researches mostly focused on pitaya cultivation, biological characteristics, fresh‐keeping, and lacked analyses about chemical composition of pitaya. Therefore, ethanol extraction and GC/MS were used to extract and identify the bioactive components in pulp and pericarp of red pitaya and white pitaya. The extracting results showed that percentages of ethanol extracts from pulp and pericarp of red pitaya were 14.5% and 12%, whereas those of white pitaya were 16% and 12%. The GC/MS results showed that different kinds of bioactive constituents were identified in fresh pericarp and pulp of red pitaya and white pitaya. In the four ethanol extracts, there are rich polysiloxane plant organosilicon with total contents of 10.09%, 24.21%, 25.77%, and 23.25%. Meanwhile, there are many heterocyclic substances, and the content of pericarp is much higher than that of pulp. The four ethanol extracts also contain some other bioactive ingredients, such as esters, hydrocarbons, alcohols, amides, halides, and fatty acids, which can be used as raw materials for biomedicine, advanced cosmetics, and skin care products.

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“…2021 年, 王凯凯等 [64] 报道了无金属催化合成四氮杂䓬103 的反应(Scheme 32). 亚胺叶立德 99 和 1,3,5-三嗪烷分别作为双原子和五原子合成子, 参与 N-磺酰基-1,2,3-三氮唑可通过铜催化炔-叠氮化物的环加成反应顺利制得, 在适当的过渡金属催化剂作用下, 可转化为 α-亚氨基金属卡宾, 因此引起了有机化学工作者极大的研究兴趣 [65][66][67][68][69][70][71] . 鲍晓光等 [72] 报道了一种铑催化三氮唑[2＋5]环化合成八氢嘌呤 105 骨架的方法 (Scheme 33).…”

Section: 其它unclassified

Research Progress of 1,3,5-Triazinanes in the Synthesis of Nitrogen-Containing Heterocycles

Zhang¹,

Zhou²,

Xiao³

et al. 2021

Chinese Journal of Organic Chemistry

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1,3,5-Triazinanes are an important class of synthons, which could be regarded as the equivalent of formaldehyde imines in constructing various nitrogen-containing heterocyclic skeletons. In recent years, 1,3,5-triazinanes have attracted much attention in the construction of nitrogen-containing heterocyclic compounds. Based on this, the participation of 1,3,5-triazinanes as diatomic, triatomic and four-atom synthons in [2＋n], [3＋n], [4＋n] cycloaddition reactions to construct nitrogen-containing heterocyclic compounds is systematically summarized. Its applications in cycloaddition, heterocyclic chemistry and pharmaceutical chemistry are also summarized. Moreover, the development of 1,3,5-triazinanes in the construction of nitrogen-containing heterocyclic skeletons and their future applications are also prospected.

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Recent Advances in the Synthesis of Heterocycles and Related Substances Based on α‐Imino Rhodium Carbene Complexes Derived from N‐Sulfonyl‐1,2,3‐triazoles

Cited by 206 publications

References 109 publications

Recent Advances in Theoretical Studies on Transition-Metal-Catalyzed Carbene Transformations

Recent Advances in Theoretical Studies on Transition-Metal-Catalyzed Carbene Transformations

Constituent diversity of ethanol extracts from pitaya

Research Progress of 1,3,5-Triazinanes in the Synthesis of Nitrogen-Containing Heterocycles

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