5720-05-8Relevant articles and documents
Atropisomerism of the C-1-C′-1 axis of 2,2′,8,8′-unsubstituted 1,1′-binaphthyl derivatives
Chow,Wan
, p. 5042 - 5047 (2001)
The Suzuki coupling of optically active (S)-binaphthyl bromide 10 with (S)-binaphthyl boronic acid 11 produced a diastereomeric mixture of tetrahydroxyquaternaphthyls 4. The coupling products 4 as well as their derivatives 5-7 can be considered as members of the family of 1,1′-binaphthyl-3,3′-diols. The C-1-C′-1 axis of all these compounds was found to have an unusually high rotational barrier. Generally, the barrier is higher for derivatives having more bulky substituents at the 3 and 3′ positions.
Bipyridinium and Phenanthrolinium Dications for Metal-Free Hydrodefluorination: Distinctive Carbon-Based Reactivity
Burton, Katherine I.,Elser, Iris,Waked, Alexander E.,Wagener, Tobias,Andrews, Ryan J.,Glorius, Frank,Stephan, Douglas W.
supporting information, p. 11730 - 11737 (2021/07/16)
The development of novel Lewis acids derived from bipyridinium and phenanthrolinium dications is reported. Calculations of Hydride Ion Affinity (HIA) values indicate high carbon-based Lewis acidity at the ortho and para positions. This arises in part from extensive LUMO delocalization across the aromatic backbones. Species [C10H6R2N2CH2CH2]2+ (R=H [1 a]2+, Me [1 f]2+, tBu [1 g]2+), and [C12H4R4N2CH2CH2]2+ (R=H [2 a]2+, Me [2 b]2+) were prepared and evaluated for use in the initiation of hydrodefluorination (HDF) catalysis. Compound [2 a]2+ proved highly effective towards generating catalytically active silylium cations via Lewis acid-mediated hydride abstraction from silane. This enabled the HDF of a range of aryl- and alkyl- substituted sp3(C?F) bonds under mild conditions. The protocol was also adapted to effect the deuterodefluorination of cis-2,4,6-(CF3)3C6H9. The dications are shown to act as hydride acceptors with the isolation of neutral species C16H14N2 (3 a) and C16H10Me4N2 (3 b) and monocationic species [C14H13N2]+ ([4 a]+) and [C18H21N2]+ ([4 b]+). Experimental and computational data provide further support that the dications are initiators in the generation of silylium cations.
Preparation method of trans-ketone intermediate
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Paragraph 0086-0090; 0092, (2021/06/06)
The invention discloses a preparation method of trans-ketone intermediates. The trans-ketone intermediates comprise compounds as shown in a formula (I) and a formula (II). The preparation process comprises the following steps: (1) performing catalytic hydrogenation on the compounds as shown in the formula (I) to prepare ketone intermediate products; (2) preparing a Grignard reagent from benzyloxy halogenated benzene and magnesium powder, and performing acidolysis dehydration on the Grignard reagent and the ketone intermediate product prepared in the step (1) to obtain a compound as shown in a formula (II); and (3) carrying out catalytic hydrogenation and isomerization reaction on the compound as shown in the formula (II) prepared in the step (2). According to the preparation method provided by the invention, the technical problem that multiple benzyl alcohol impurities and impurity products after ketone condensation exist in acidolysis dehydration products of dicyclohexanone ethylene monoketal adopted in a traditional process is solved, and the purification difficulty of trans-ketone intermediate products is greatly reduced.
Transition-Metal-Free Borylation of Aryl Bromide Using a Simple Diboron Source
Han, Min Su,Lim, Taeho,Ryoo, Jeong Yup
, p. 10966 - 10972 (2020/09/23)
In this study, we developed a simple transition-metal-free borylation reaction of aryl bromides. Bis-boronic acid (BBA), was used, and the borylation reaction was performed using a simple procedure at a mild temperature. Under mild conditions, aryl bromides were converted to arylboronic acids directly without any deprotection steps and purified by conversion to trifluoroborate salts. The functional group tolerance was considerably high. The mechanism study suggested that this borylation reaction proceeds via a radical pathway.
Aryl boronic acid preparation method
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Paragraph 0031-0032, (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.
Palladium-catalyzed B-diarylation of diethylaminoborane for the synthesis of diarylborinic acids
Igarashi, Takuya,Shimazumi, Ryoma,Tobisu, Mamoru
supporting information, p. 760 - 763 (2020/07/10)
The palladium-catalyzed synthesis of diarylborinic acid derivatives by intermolecular cross-coupling between aryl iodides and (amino)dihydrideborane is reported. The key to success of the reaction is the use of a less bulky diethylaminoborane reagent, which facilitates the second B-arylation.
Enantioselective Conjugate Addition of Aryl Halides and Triflates to Electron-Deficient Olefins via Nickel- And Rhodium-Catalyzed Sequential Relay Reactions
Fan, Chenrui,Wu, Qixu,Zhu, Chengfeng,Wu, Xiang,Li, Yougui,Luo, Yunfei,He, Jian-Bo
supporting information, p. 8888 - 8892 (2019/10/14)
Asymmetric conjugate addition of aryl halides or aryl triflates to electron-deficient olefins was realized by sequential Miyaura borylation and Hayashi-Miyaura conjugate addition in one pot. A nickel-catalyzed borylation of aryl halides or triflates and a rhodium-chiral diene complex catalyzed enantioselective conjugate addition was executed as a pair of relay reactions as a more efficient and greener protocol.
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 (2019/07/31)
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.
IRIDIUM COMPLEX, COMPOSITION HAVING THE SAME, AND USE THEREOF
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Paragraph 0094-0096, (2020/04/16)
The present invention relates to an iridium complex which is a compound represented by chemical formula 1, a composition comprising an iridium complex, and uses thereof. In the chemical formula 1, R^1 to R^8, and A are as defined in claim 1. The present invention can provide the iridium complex that can be effectively applied to the regulation of amyloid beta peptide aggregation.(AA) [Strategy 1] Inhibition(BB) [Strategy 2] OxidationCOPYRIGHT KIPO 2020
Magnesium promoted autocatalytic dehydrogenation of amine borane complexes: A reliable, non-cryogenic, scalable access to boronic acids
Marciasini, Ludovic D.,Richard, Jimmy,Cacciuttolo, Bastien,Sartori, Guillaume,Birepinte, Melodie,Chabaud, Laurent,Pinet, Sandra,Pucheault, Mathieu
, p. 164 - 171 (2018/12/05)
Owing to the unusual reactivity of dialkylamine-borane complexes, a methodology was developed to simply access boronic acids. The intrinsic instability of magnesium aminoborohydride was tweaked into a tandem dehydrogenation borylation sequence. Proceeding via an autocatalytic cycle, amineborane dehydrogenation was induced by a variety of Grignard reagents. Overall, addition of the organomagnesium species onto specially designed dialkylamine-borane complexes led to a variety of boronic acids in high yields. In addition, the reaction can be performed under Barbier conditions, on a large scale.
