33646-40-1Relevant academic research and scientific papers
RADICAL BASED MECHANOCHROMIC MONOMERS AND SELF-REPORTING POLYMERS
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Paragraph 0177; 0179; 0181; 0183; 0185, (2021/10/05)
The present invention relates to a radical-based mechanochromic monomer which changes color by mechanical stimuli such as pressing, bending, tearing, tensile and the like, and can be usefully used as a physical stimulus-sensitive sensor, a self-reporting smart polymer material, or the like by utilizing a polymer prepared from the monomer according to the present invention.
Constructing a triangular metallacycle with salen-Al and its application to a catalytic cyanosilylation reaction
Li, Bo,Li, Yang,Qiu, Huayu,Xu, Jun,Yin, Shouchun,Zhang, Jinjin,Zhang, Pengfei,Zhang, Yueyue
, p. 10399 - 10402 (2021/10/12)
A triangular metallosalen-based metallacycle was constructed in quantitative yield by the self-assembly of a 180° bis(pyridyl)salen-Al complex and a 60° diplatinum(ii) acceptor in a 1?:?1 stoichiometric ratio. This metallacycle was then successfully used to cyanosilylate a wide range of benzaldehydes with trimethylsilyl cyanide.
Synthesis and antitumor activity of sacroflavonoside
Wang, Qinghu,Xin, Ying,Pa, Biligetu,He, Xiang,Bao, Wenqiang
, p. 1292 - 1298 (2019/08/12)
Sacroflavonoside, a new derivative of diphenylethene, was isolated from Artemisia sacrorum, which have been found to possess the inhibitory effect on the proliferation of gastric carcinoma cells (MKN-45) in vitro in our previous studies. With anisaldehyde (SM-A) as starting material, the sacroflavonoside was synthesized by nucleophilic addition, electrophilic substitution and dehydration cyclization. The structure of sacroflavonoside was established by 1 D (1H NMR and 13C NMR) and 2 D-NMR (HSQC and HMBC) spectral analysis. The antitumor activity and potential mechanism against MKN-45 cells of sacroflavonoside were evaluated in vitro. The results showed that sacroflavonoside could significantly induce MKN-45 cells apoptosis and autophagy by increasing the expression of Bax, Caspase-3, Beclin1 and LC3-II proteins and decreasing the expression of Bcl-2 protein at low micromole level. This investigation provided a valuable lead structure for the development of antitumor drugs.
Topology-Based Functionalization of Robust Chiral Zr-Based Metal-Organic Frameworks for Catalytic Enantioselective Hydrogenation
Jiang, Hong,Zhang, Wenqiang,Kang, Xing,Cao, Ziping,Chen, Xu,Liu, Yan,Cui, Yong
supporting information, p. 9642 - 9652 (2020/07/02)
The design and development of robust and porous supported catalysts with high activity and selectivity is extremely significant but very challenging for eco-friendly synthesis of fine chemicals and pharmaceuticals. We report here the design and synthesis of highly stable chiral Zr(IV)-based MOFs with different topologies to support Ir complexes and demonstrate their network structures-dependent asymmetric catalytic performance. Guided by the modulated synthesis and isoreticular expansion strategy, five chiral Zr-MOFs with a flu or ith topology are constructed from enantiopure 1,1′-biphenol-derived tetracarboxylate linkers and Zr6, Zr9, or Zr12 clusters. The obtained MOFs all show high chemical stability in boiling water, strongly acidic, and weakly basic aqueous solutions. The two flu MOFs featuring the dihydroxyl groups of biphenol in open and large cages, after sequential postsynthetic modification with P(NMe2)3 and [Ir(COD)Cl]2, can be highly efficient and recyclable heterogeneous catalysts for hydrogenation of α-dehydroamino acid esters with up to 98% ee, whereas the three ith MOFs featuring the dihydroxyl groups in small cages cannot be installed with P(NMe2)3 to support the Ir complex. Incorporation of Ir-phosphorus catalysts into Zr-MOFs leads to great enhancement of their chemical stability, durability, and even stereoselectivity. This work therefore not only advances Zr-MOFs as stable supports for labile metal catalysts for heterogeneous asymmetric catalysis but also provides a new insight into how highly active chiral centers can result due to the framework topology.
Combining Photo-Organo Redox- and Enzyme Catalysis Facilitates Asymmetric C-H Bond Functionalization
Zhang, Wuyuan,Fueyo, Elena Fernandez,Hollmann, Frank,Martin, Laura Leemans,Pesic, Milja,Wardenga, Rainer,H?hne, Matthias,Schmidt, Sandy
supporting information, p. 80 - 84 (2019/01/04)
In this study, we combined photo-organo redox catalysis and biocatalysis to achieve asymmetric C–H bond functionalization of simple alkane starting materials. The photo-organo catalyst anthraquinone sulfate (SAS) was employed to oxyfunctionalise alkanes to aldehydes and ketones. We coupled this light-driven reaction with asymmetric enzymatic functionalisations to yield chiral hydroxynitriles, amines, acyloins and α-chiral ketones with up to 99 % ee. In addition, we demonstrate functional group interconversion to alcohols, esters and carboxylic acids. The transformations can be performed as concurrent tandem reactions. We identified the degradation of substrates and inhibition of the biocatalysts as limiting factors affecting compatibility, due to reactive oxygen species generated in the photocatalytic step. These incompatibilities were addressed by reaction engineering, such as applying a two-phase system or temporal and spatial separation of the catalysts. Using a selection of eleven starting alkanes, one photo-organo catalyst and 8 diverse biocatalysts, we synthesized 26 products and report for the model compounds benzoin and mandelonitrile > 97 % ee at gram scale.
Highly chemoselective and efficient Strecker reaction of aldehydes with TMSCN catalyzed by MgI2 etherate under solvent-free conditions
He, Kailun,Liu, Huijun,Zhang, Xingxian,Zhou, Jing
supporting information, p. 933 - 936 (2019/03/08)
Strecker reaction of various substituted aromatic aldehydes, heteroaromatic aldehydes, aliphatic aldehydes and α,β-unsaturated aldehydes with trimethylsilyl cyanide (TMSCN) was realized in the presence of 5 mol % of MgI2 etherate in a mild, efficient and highly chemoselective manner under solvent-free conditions.
Postfunctionalized Metalloligand-Based Catenated Coordination Polymers: Syntheses, Structures, and Effect of Labile Sites on Catalysis
Pandey, Saurabh,Kumar, Girijesh,Gupta, Rajeev
, p. 2723 - 2735 (2019/05/01)
In this work, pyridyl-appended Co3+ complexes (1 and 2) have been postfunctionalized by using 4-(bromomethyl)benzoic acid, thus changing the functionalities from pyridyl-N donors to carboxylate-O donors. Using two such postfunctionalized metalloligands (3 and 4), several homo and heterometallic coordination polymers (HCPs) have been synthesized. Single crystal structural analyses revealed that all HCPs presented intriguing one-dimensional catenated architectures. Postsynthetic modification induced flexibility was found to be responsible for the nearly identical architectures for two sets of HCPs starting from two different postfunctionalized metalloligands, 3 and 4. Two sets of HCPs differed by the presence (3a-3d) or absence (4a-4b) of labile coordinated water molecules that demonstrated a profound effect on the heterogeneous catalysis of Knoevenagel condensation reactions and cyanation reactions.
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.
Tetraarylsuccinonitriles as mechanochromophores to generate highly stable luminescent carbon-centered radicals
Sumi, Toshikazu,Goseki, Raita,Otsuka, Hideyuki
supporting information, p. 11885 - 11888 (2017/11/06)
This communication reports on the design and synthesis of mechanochromophores with a dynamic covalent system composed of a tetraarylsuccinonitrile skeleton that generate a metastable organic luminescent carbon radical. The mechanically generated radical species showed pink color and yellow light emission under UV irradiation. Unusually high stability of the luminescent carbon-centered radicals was also observed in a polymer system.
Acceptorless and Base-free Dehydrogenation of Cyanohydrin with (η6-Arene)halide(Bidentate Phosphine)ruthenium(II) Complex
Kim, Kicheol,Moeljadi, Adhitya Mangala Putra,Hirao, Hajime,Hong, Soon Hyeok
supporting information, p. 3292 - 3298 (2017/09/06)
Ruthenium-catalyzed dehydrogenation of cyanohydrins under acceptorless and base-free conditions was demonstrated for the first time in the synthesis of acyl cyanide. As opposed to the thermodynamically preferred elimination of hydrogen cyanide, the dehydrogenation of cyanohydrins could be kinetically controlled with ruthenium (II) bidentate phosphine complexes. The effects of the arene, phosphine ligands and counter anions were investigated in regard to catalytic activity and selectivity. Selective dehydrogenation can occur via β-hydride elimination with the experimentally observed [(alkoxide)Ru] complex. (Figure presented.).
