1765-93-1Relevant articles and documents
Chemical strategies to modify amyloidogenic peptides using iridium(iii) complexes: Coordination and photo-induced oxidation
Kang, Juhye,Nam, Jung Seung,Lee, Hyuck Jin,Nam, Geewoo,Rhee, Hyun-Woo,Kwon, Tae-Hyuk,Lim, Mi Hee
, p. 6855 - 6862 (2019)
Amyloidogenic peptides are considered central pathological contributors towards neurodegeneration as observed in neurodegenerative disorders [e.g., amyloid-β (Aβ) peptides in Alzheimer's disease (AD)]; however, their roles in the pathologies of such diseases have not been fully elucidated since they are challenging targets to be studied due to their heterogeneous nature and intrinsically disordered structure. Chemical approaches to modify amyloidogenic peptides would be valuable in advancing our molecular-level understanding of their involvement in neurodegeneration. Herein, we report effective chemical strategies for modification of Aβ peptides (i.e., coordination and coordination-/photo-mediated oxidation) implemented by a single Ir(iii) complex in a photo-dependent manner. Such peptide variations can be achieved by our rationally designed Ir(iii) complexes (Ir-Me, Ir-H, Ir-F, and Ir-F2) leading to significantly modulating the aggregation pathways of two main Aβ isoforms, Aβ40 and Aβ42, as well as the production of toxic Aβ species. Overall, we demonstrate chemical tactics for modification of amyloidogenic peptides in an effective and manageable manner utilizing the coordination capacities and photophysical properties of transition metal complexes.
Asymmetric 1,4-Addition of Arylboronic Acids to β,γ-Unsaturated α-Ketoesters using Heterogeneous Chiral Metal Nanoparticle Systems
Miyamura, Hiroyuki,Yasukawa, Tomohiro,Zhu, Zhiyuan,Kobayashi, Shū
supporting information, p. 353 - 359 (2019/12/15)
Asymmetric 1,4-addition reactions with β,γ-unsaturated α-ketoesters are valuable because the resulting chiral ketoester compounds can be converted into various useful species that are often used as chiral building blocks in drug and natural product synthesis. However, β,γ-unsaturated α-ketoesters have two reactive points in terms of nucleophilic additions, which will lead to the 1,4-adduct, the 1,2-adduct and to the combined 1,4- and 1,2-adduct. Therefore, controlling this chemoselectivity is an important factor for the development of these transformations. Here, we developed an asymmetric 1,4-addition of aryl boronic acids to β,γ-unsaturated α-ketoesters by using heterogeneous chiral rhodium nanoparticle systems with a chiral diene ligand bearing a secondary amide moiety. The newly developed polydimethylsilane-immobilized rhodium nanoparticle catalysts showed high activity, high chemoselectivity, and excellent enantioselectivity, and this is the first heterogeneous catalytic system for this asymmetric reaction. Metal nanoparticle catalysts were recovered and reused without loss of activity or leaching of metal. (Figure presented.).
Aryl boronic acid preparation method
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Paragraph 0033-0036; 0040-0041, (2020/01/25)
The invention belongs to the technical field of fine chemical engineering, and relates to an aryl boronic acid preparation method. In the prior art, aryl boronic acid as a novel safe and environmentally-friendly arylation reagent is widely used in scientific research and production of various fine chemicals containing aryl structures in the fields of medicines, pesticides, advanced materials and the like; and the aryl boronic acid compound preparation method reported in the disclosed literature has problems of harsh reaction conditions and high cost. A purpose of the invention is to provide amethod, wherein an aryl boron compound is formed by carrying out a reaction on a Grignard reagent and trialkyl borate under mild conditions, the composition of the aryl boron compound is converted from the main component diaryl borate into the main component aryl borate, and the aryl borate is hydrolyzed to obtain aryl boric acid, so that the preparation cost of the acyl aryl boric acid compound can be remarkably reduced, and the method has good practical application prospect.