131350-12-4Relevant academic research and scientific papers
Encapsulation of Homogeneous Catalysts in Mesoporous Materials Using Diffusion-Limited Atomic Layer Deposition
Zhang, Shufang,Zhang, Bin,Liang, Haojie,Liu, Yequn,Qiao, Yan,Qin, Yong
supporting information, p. 1091 - 1095 (2018/01/01)
The heterogenization of homogeneous metal complex catalysts has attracted great attention. The encapsulation of metal complexes into nanochannels of mesoporous materials is achieved by coating metal oxides at/near the pore entrance by diffusion-limited atomic layer deposition (ALD) to produce a hollow plug. The pore size of the hollow plug is precisely controlled on the sub-nanometer scale by the number of ALD cycles to fit various metal complexes with different molecular sizes. Typically, Co or Ti complexes are successfully encapsulated into the nanochannels of SBA-15, SBA-16, and MCM-41. The encapsulated Co and Ti catalysts show excellent catalytic activity and reusability in the hydrolytic kinetic resolution of epoxides and asymmetric cyanosilylation of carbonyl compounds, respectively. This ALD-assisted encapsulation method can be extended to the encapsulation of other homogeneous catalysts into different mesoporous materials for various heterogeneous reactions.
Chiral Metal-Organic Framework Decorated with TEMPO Radicals for Sequential Oxidation/Asymmetric Cyanation Catalysis
Li, Zijian,Liu, Yan,Kang, Xing,Cui, Yong
supporting information, p. 9786 - 9789 (2018/08/28)
A chiral porous metal-organic framework (MOF) decorated with radicals has been successfully constructed by cocrystallizing achiral (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)-substituted tricarboxylate and enantiopure VO(salen)-derived dipyridine ligands. The chiral MOF can function as an efficient heterogeneous catalyst for the sequential alcohol oxidation/asymmetric cyanation of aldehyde reactions with enhanced activity and enantioselectivity compared to the homogeneous counterpart.
Multivariate Metal-Organic Frameworks as Multifunctional Heterogeneous Asymmetric Catalysts for Sequential Reactions
Xia, Qingchun,Li, Zijian,Tan, Chunxia,Liu, Yan,Gong, Wei,Cui, Yong
supporting information, p. 8259 - 8266 (2017/06/28)
The search for versatile heterogeneous catalysts with multiple active sites for broad asymmetric transformations has long been of great interest, but it remains a formidable synthetic challenge. Here we demonstrate that multivariate metal-organic frameworks (MTV-MOFs) can be used as an excellent platform to engineer heterogeneous catalysts featuring multiple and cooperative active sites. An isostructural series of 2-fold interpenetrated MTV-MOFs that contain up to three different chiral metallosalen catalysts was constructed and used as efficient and recyclable heterogeneous catalysts for a variety of asymmetric sequential alkene epoxidation/epoxide ring-opening reactions. Interpenetration of the frameworks brings metallosalen units adjacent to each other, allowing cooperative activation, which results in improved efficiency and enantioselectivity over the sum of the individual parts. The fact that manipulation of molecular catalysts in MTV-MOFs can control the activities and selectivities would facilitate the design of novel multifunctional materials for enantioselective processes.
The first porphyrin-salen based chiral metal-organic framework for asymmetric cyanosilylation of aldehydes
Li, Jiawei,Ren, Yanwei,Qi, Chaorong,Jiang, Huanfeng
supporting information, p. 8223 - 8226 (2017/07/24)
The first porphyrin-salen based chiral metal-organic framework (ps-CMOF) constructed by judiciously incorporating metalloporphyrin and metallosalen struts into one MOF structure is reported, which can serve as an effective heterogeneous catalyst for the a
A homochiral vanadium-salen based cadmium bpdc MOF with permanent porosity as an asymmetric catalyst in solvent-free cyanosilylation
Bhunia, Asamanjoy,Dey, Subarna,Moreno, José María,Diaz, Urbano,Concepcion, Patricia,Van Hecke, Kristof,Janiak, Christoph,Van Der Voort, Pascal
supporting information, p. 1401 - 1404 (2016/01/25)
A homochiral vanadium-salen based MOF with the pcu topology is constructed via in situ synthesis under solvothermal conditions. The synthesized MOF exhibits BET surface areas of 574 m2 g-1, showing the highest H2 adsorptio
A hand natural acid radical ammonium salt crystal preparation and use
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Paragraph 0039; 0040, (2017/01/26)
The invention relates to a chiral amide salt crystal. The chemical formula of the chiral amide salt crystal is as shown in the specification. The (R)-3-methyl-butyl-1-hydroxymethylaminoformic acid-(R)-3-methyl-butyl-1-hydroxymethyl ammonium salt crystal s
Chiral metal?Organic framework as a platform for cooperative catalysis in asymmetric cyanosilylation of aldehydes
Zhu, Chengfeng,Xia, Qingchun,Chen, Xu,Liu, Yan,Du, Xia,Cui, Yong
, p. 7590 - 7596 (2018/05/23)
In this work, we demonstrate cooperative asymmetric catalysis by a metal?organic framework (MOF) as exemplified in the context of catalyzing cyanation of aldehydes with a VO(salen)-MOF, which after oxidation affords remarkably increased stereoselectivity (up to >99% ee) compared to the homogeneous VO(salen) counterpart as a result of the pairs of VO(salen) units in close proximity within its open channels. The cooperative asymmetric catalysis has been evidenced by the significantly decreased stereoselectivity and activity when one VO(salen) in such pairs of VO(salen) units is replaced with one Cu(salen), which results in blocking the VO?VO synergistic pathway while prompting unimolecular activation of substrates. The heterogeneous nature of VO(salen)-MOF has been verified by the fact that it can be easily recycled and reused without significant loss of catalytic activity and enantioselectivity, and its practical utility as asymmetric cyanation catalysist has been illustrated in the gram-scale synthesis of the antiviral natural products (R)- and (S)-enantiomers of tembamide. Our work therefore advances chiral MOF as an attractive platform for cooperative asymmetric catalysis in a variety of syntheses.
Direct and Post-Synthesis Incorporation of Chiral Metallosalen Catalysts into Metal-Organic Frameworks for Asymmetric Organic Transformations
Xi, Weiqin,Liu, Yan,Xia, Qingchun,Li, Zijian,Cui, Yong
supporting information, p. 12581 - 12585 (2015/09/01)
Two chiral porous metal-organic frameworks (MOFs) were constructed from [VO(salen)]-derived dicarboxylate and dipyridine bridging ligands. After oxidation of VIV to VV, they were found to be highly effective, recyclable, and reusable
Enantioselective cyanosilylation of aldehydes catalyzed by a multistereogenic salen-Mn(III) complex with a rotatable benzylic group as a helping hand
Wei, Yun-Long,Huang, Wei-Sheng,Cui, Yu-Ming,Yang, Ke-Fang,Xu, Zheng,Xu, Li-Wen
, p. 3098 - 3103 (2015/02/02)
A multistereogenic salen-Mn(iii) complex bearing an aromatic pocket and two benzylic groups as helping hands was found to be efficient in the catalysis of asymmetric cyanosilylation. The salen-Mn catalyst partially mimics the functions of biocatalysts by
A homochiral metal-organic framework as an effective asymmetric catalyst for cyanohydrin synthesis
Mo, Ke,Yang, Yuhua,Cui, Yong
supporting information, p. 1746 - 1749 (2014/03/21)
A homochiral metal-organic framework (MOF) of an enantiopure 2,2′-dihydroxy-1,1′-biphenyl ligand was constructed. After exchanging one proton of the dihydroxyl group for Li(I) ions, the framework is shown to be a highly efficient and recyclable heterogene
