6793-92-6Relevant academic research and scientific papers
Interplay between the crystal stability and the energy of the molecular conformation
Dyk, Konrad,Baran, ?ukasz,R?ysko, Wojciech,Stankevi?, Marek,Kamiński, Daniel M.
, p. 2683 - 2694 (2021/04/19)
A specially designed new compound, 5,5′-bis(4-hydroxyphenyl)-2,2′-dihydroxy-1,1′-biphenyl, can crystallize in different crystallographic systems. The molecule adopts theC-conformation for the torsion angle of around 60° and theT-conformation for the angle of around 130°, which differ in energy by ～0.8 kJ mol?1. Theoretical studies for the gaseous phase show that theC-conformer has a lower energy. However, crystallization experiments show that the most stable crystal structure consists of only the energetically less stableT-conformer. On the other hand, fast crystal growth at low temperature and crystal growth after milling both lead to the formation of metastable crystals in which the studied molecule adopts theC-conformation. Our study shows that the total crystal net energy is the main factor in determining the molecular conformations even if the molecular conformation has a higher energy in the gaseous phase.
Self-assembling behaviour of chiral calamitic monoacrylates targeted for polymer stabilisation of polar smectic phases in chiral liquid crystals
Dmochowska, Ewelina,Herman, Jakub,Czerwiński, Micha?,Stulov, Sergei,Bubnov, Alexej,Kula, Przemys?aw
, (2021/03/03)
The stabilisation and control of synclinic and anticlinic chiral liquid crystalline phases remain an actual and highlighted task. This work presents the design and mesomorphic properties of new chiral calamitic reactive mesogens, monoacrylates, based on biphenyl benzoate and phenyl biphenyl-4-carboxylate cores with reactive terminal groups placed far from the chiral chain. The compound's structures, compatible with the components of modern ferroelectric and antiferroelectric liquid crystalline mixtures, are confirmed by mass spectrometry (electron ionization) analysis and proton/carbon nuclear magnetic resonance. All the reactive mesogens possess the self-assembling, i.e. liquid crystalline behaviour with high tendency to create smectic phases in a broad temperature range, which was confirmed by a polarizing optical microscopy, differential scanning calorimetry and broad-band dielectric spectroscopy. Doping of advanced multicomponent mixtures possessing the chiral smectic phases by the designed monoacrylates with further cross-linking procedure, can be an effective and functional tool for stabilising ferroelectric and antiferroelectric phases in various states and hence, can allow the symmetrisation of the switching times in the modes employed surface stabilised geometry; this is a very highlighted task for optoelectronics. Moreover, an evident considerable tendency for thermal polymerisation of specific reactive mesogens can reduce the drawbacks of polymer stabilisation.
A facile and versatile electro-reductive system for hydrodefunctionalization under ambient conditions
Huang, Binbin,Guo, Lin,Xia, Wujiong
supporting information, p. 2095 - 2103 (2021/03/26)
A general electrochemical system for reductive hydrodefunctionalization is described, employing the inexpensive and easily available triethylamine (Et3N) as a sacrificial reductant. This protocol is characterized by facile operation, sustainable conditions, and exceptionally wide substrate scope covering the cleavage of C-halogen, N-S, N-C, O-S, O-C, C-C and C-N bonds. Notably, the selectivity and capability of reduction can be conveniently switched by simple incorporation or removal of an alcohol as a co-solvent.
Transition-Metal-Free and Base-Promoted Carbon-Heteroatom Bond Formation via C-N Cleavage of Benzyl Ammonium Salts
Liu, Long,Tang, Yuanyuan,Wang, Kunyu,Huang, Tianzeng,Chen, Tieqiao
, p. 4159 - 4170 (2021/03/09)
A facile and general method for constructing carbon-heteroatom (C-P, C-O, C-S, and C-N) bonds via C-N cleavage of benzyl ammonium salts under transition-metal-free conditions was reported. The combination of t-BuOK and 18-crown-6 enabled a wide range of substituted benzyl ammonium salts to couple readily with different kinds of heteroatom nucleophiles, i.e. hydrogen phosphoryl compounds, alcohols, thiols, and amines. Good functional group tolerance was demonstrated. The scale-up reaction and one-pot synthesis were also successfully performed.
N2-substituted alkoxy aromatic cyclo-2-aminopyrimidine derivative and application thereof
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Paragraph 0107-0108, (2020/09/20)
The invention provides an N2-substituted alkoxy aromatic cyclo-2-aminopyrimidine derivative and application thereof. The N2-substituted alkoxy aromatic cyclo-2-aminopyrimidine derivative comprises anoptical isomer and pharmaceutically acceptable salt thereof. Preliminary pharmacodynamic indication shows that the compound disclosed by the invention has FLT3 inhibitory activity, wherein the proliferation inhibition activity is realized on various leukemia cell strains; moreover, the derivative is effective for multiple mutations of AML, such as internal tandem repeat mutation of a near-membranestructural domain and D835 point mutation of an activated ring in a kinase structural domain and almost has no inhibition effect on c-KIT. The derivative can overcome drug resistance brought by clinical point mutation, can reduce toxic and side effects of bone marrow inhibition, and can be applied to preparation of antitumor drugs. The general structural formula of the derivative is shown in thespecification.
The Cyclopropane Ring as a Reporter of Radical Leaving-Group Reactivity for Ni-Catalyzed C(sp3)-O Arylation
Mills, L. Reginald,Monteith, John J.,Dos Passos Gomes, Gabriel,Aspuru-Guzik, Alán,Rousseaux, Sophie A. L.
supporting information, p. 13246 - 13254 (2020/09/01)
The ability to understand and predict reactivity is essential for the development of new reactions. In the context of Ni-catalyzed C(sp3)-O functionalization, we have developed a unique strategy employing activated cyclopropanols to aid the design and optimization of a redox-active leaving group for C(sp3)-O arylation. In this chemistry, the cyclopropane ring acts as a reporter of leaving-group reactivity, since the ring-opened product is obtained under polar (2e) conditions, and the ring-closed product is obtained under radical (1e) conditions. Mechanistic studies demonstrate that the optimal leaving group is redox-active and are consistent with a Ni(I)/Ni(III) catalytic cycle. The optimized reaction conditions are also used to synthesize a number of arylcyclopropanes, which are valuable pharmaceutical motifs.
Convergent Total Synthesis of Lamellarins and Their Congeners
Morikawa, Daiki,Morii, Kazuki,Yasuda, Yuto,Mori, Atsunori,Okano, Kentaro
, p. 8603 - 8617 (2020/07/16)
A convergent total synthesis of lamellarins S and Z is described. The synthesis features a halogen dance of an easily accessible α,β-dibromopyrrole promoted by an ester moiety. The resultant β,β′-dibromopyrrole undergoes a ligand-controlled Suzuki-Miyaura coupling to provide a range of diarylated pyrrole derivatives. The established synthetic method was also applicable to the synthesis of ningalin B and lukianols A and B.
Preparation and application of aminourea-sensitive amine oxidase inhibitor
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Paragraph 0171-0175, (2020/04/17)
The invention provides preparation and application of an aminourea-sensitive amine oxidase inhibitor. Specifically, the invention discloses a compound as shown in a formula I which is described in thespecification or a stereoisomer or racemate or a pharmaceutically acceptable salt thereof. The invention also discloses the capability of the compound in inhibition of aminourea-sensitive amine oxidase.
Preparation method of hydroxyphenylboronic acid
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Paragraph 0022-0024, (2020/05/08)
The invention discloses a preparation method of hydroxyphenylboronic acid, which belongs to the technical field of boric acid synthesis in medical intermediates. The method comprises the following steps: starting from bromophenol, carrying out BOC, trimethylsilyl or benzyl protection, forming a Grignard reagent, reacting with borate, or carrying out one-pot reaction with borate and n-butyllithium,and hydrolyzing to obtain hydroxyphenylboronic acid. According to the invention, cheap and easily available protecting groups are adopted, so that the protecting groups are easy to remove during boronation reaction hydrolysis, industrial amplification is easy to realize, batch production is carried out on the scale of dozens of kilograms, and the process stability is good.
Cooperativity within the catalyst: alkoxyamide as a catalyst for bromocyclization and bromination of (hetero)aromatics
Mondal, Haripriyo,Sk, Md Raja,Maji, Modhu Sudan
supporting information, p. 11501 - 11504 (2020/10/12)
Alkoxyamide has been reported as a catalyst for the activation ofN-bromosuccinimide to perform bromocyclization and bromination of a wide range of substrates in a lipophilic solvent, where adequate suppression of the background reactions was observed. The key feature of the active site is the alkoxy group attached to the sulfonamide moiety, which facilitates the acceptance as well as the delivery of bromonium species from the bromine source to the substrates.
