59016-93-2Relevant academic research and scientific papers
Preparation method 4 - hydroxymethylphenylboronic acid
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Paragraph 0055; 0059-0061; 0085; 0089-0091; 005-0096, (2021/09/08)
The invention relates to the technical field of organic synthesis. The invention specifically discloses a preparation method of 4 -hydroxymethylphenylboronic acid. To the preparation method, bromobenzyl alcohol is taken as a raw material, Grignard reagent
Boronic Ester Based Vitrimers with Enhanced Stability via Internal Boron-Nitrogen Coordination
Zhang, Xiaoting,Wang, Shujuan,Jiang, Zikang,Li, Yu,Jing, Xinli
supporting information, p. 21852 - 21860 (2021/01/11)
Boron-containing polymers have many applications resulting from their prominent properties. Organoboron species with reversible B-O bonds have been successfully employed for the fabrication of various self-healing/healable and reprocessable polymers. However, the application of the polymers containing boronic ester or boroxine linkages is limited because of their instability to water. Herein, we report the hydrolytic stability and dynamic covalent chemistry of the nitrogen-coordinating cyclic boronic diester (NCB) linkages, and a new class of vitrimers based on NCB linkages is developed through the chemical reactions of reactive hydrogen with isocyanate. Thermodynamic and kinetic studies demonstrated that NCB linkages exhibit enhanced water and heat resistance, whereas the exchange reactions between NCB linkages can take place upon heating without any catalyst. The model compounds of NCBC-X1 and NCBC-X2 containing a urethane group and urea group, respectively, also showed higher hydrolytic stability compared to that of conventional boronic esters. Polyurethane vitrimers and poly(urea-urethane) vitrimers based on NCB linkages exhibited excellent solvent resistance and mechanical properties like general thermosets, which can be repaired, reprocessed, and recycled via the transesterification of NCB linkages upon heating. Especially, vitrimers based on NCB linkages presented improved stability to water and heat compared to those through conventional boronic esters because of the existence of N → B internal coordination. We anticipate that this work will provide a new strategy for designing the next generation of sustainable materials.
BROMODOMAIN LIGANDS CAPABLE OF DIMERIZING IN AN AQUEOUS SOLUTION
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Paragraph 00689; 00698; 00699, (2015/06/11)
Described herein are monomers capable of forming a biologically useful multimer when in contact with one, two, three or more other monomers in an aqueous media. In one aspect, such monomers may be capable of binding to another monomer in an aqueous media (e.g. in vivo) to form a multimer (e.g. a dimer). Contemplated monomers may include a ligand moiety, a linker element, and a connector element that joins the ligand moiety and the linker element. In an aqueous media, such contemplated monomers may join together via each linker element and may thus be capable of modulating one or more biomolecules substantially simultaneously, e.g., modulate two or more binding domains on a protein or on different proteins.
Electrophilicity and nucleophilicity of commonly used aldehydes
Pratihar, Sanjay
, p. 5781 - 5788 (2014/07/22)
The present approach for determining the electrophilicity (E) and nucleophilicity (N) of aldehydes includes a kinetic study of KMNO4 oxidation and NaBH4 reduction of aldehydes. A transition state analysis of the KMNO4 promoted aldehyde oxidation reaction has been performed, which shows a very good correlation with experimental results. The validity of the experimental method has been tested using the experimental activation parameters of the two reactions. The utility of the present approach is further demonstrated by the theoretical versus experimental relationship, which provides easy access to E and N values for various aldehydes and offers an at-a-glance assessment of the chemical reactivity of aldehydes in various reactions. the Partner Organisations 2014.
Scope of the palladium-catalyzed aryl borylation utilizing bis-boronic acid
Molander, Gary A.,Trice, Sarah L. J.,Kennedy, Steven M.,Dreher, Spencer D.,Tudge, Matthew T.
supporting information; experimental part, p. 11667 - 11673 (2012/09/05)
The Suzuki-Miyaura reaction has become one of the more useful tools for synthetic organic chemists. Until recently, there did not exist a direct way to make the most important component in the coupling reaction, namely the boronic acid. Current methods to make boronic acids often employ harsh or wasteful reagents to prepare boronic acid derivatives and require additional steps to afford the desired boronic acid. The scope of the previously reported palladium-catalyzed, direct boronic acid synthesis is unveiled, which includes a wide array of synthetically useful aryl electrophiles. It makes use of the newly available second generation Buchwald XPhos preformed palladium catalyst and bis-boronic acid. For ease of isolation and to preserve the often sensitive C-B bond, all boronic acids were readily converted to their more stable trifluoroborate counterparts.
The preparation of two-dimensional spindle-type chromophores for second-order nonlinear optical materials
Zhang, Xiaolong,Li, Ming,Shi, Zuosen,Zhao, Lisha,Jin, Rulong,Yi, Maobin,Zhang, Daming,Cui, Zhanchen
scheme or table, p. 982 - 987 (2012/03/27)
A series of two-dimensional spindle-type chromophores has been synthesized. The detailed synthetic procedure was reported. The factors that influence the nonlinear optical properties such as the donors and acceptor character have been investigated. The chemical structures of the target products have been confirmed by IR, UV-Vis and NMR spectroscopy, elemental and thermal analysis. The spindle-type chromophores have been used to prepare host-guest doped films which exhibited very good thermal and temporal stability. The nonlinear electro-optical coefficients of the host-guest doped films were measured by the Teng-Man technique and gave values in the range from 21 to 29 pm/V.
Multistep synthesis of complex boronic acids from simple MIDA boronates
Gillis, Eric P.,Burke, Martin D.
supporting information; experimental part, p. 14084 - 14085 (2009/03/11)
Due to its sensitivity to most synthetic reagents, it is typically necessary to introduce the boronic acid functional group just prior to its utilization. Overcoming this important limitation, we herein report that air- and chromatographically stable MIDA boronates are compatible with a wide range of common reagents which enables the multistep synthesis of complex boronic acid building blocks from simple B-containing starting materials. X-ray and variable temperature NMR studies link the unique stability of MIDA boronates to a kinetic inaccessibility of the potentially reactive boron p-orbital and/or nitrogen lone pair. These findings were collectively harnessed to achieve a short and modular total synthesis of (+)-crocacin C via the iterative cross-coupling of a structurally complex, MIDA-protected haloboronic acid building block. Copyright
Process for the preparation of substituted phenylboronic acids
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, (2008/06/13)
Compounds of the formula (I) in which Q1and Q2are each OH or form a trimeric boric anhydride, Z is CHO, CH2Y, X or a protected aldehyde group, and X is CN, COOH, COCl, CONH2or C(OR)3, and Y is OH or NH2, and Z is in the o-, m- or p-position to the boronic acid radical, are prepared by a) reacting a compound of the formula (II) ?with Mg in the presence of an anthracene compound and, if desired, a transition-metal halide and, if desired, an Mg halide or in the presence of a transition-metal halide and, if desired, an Mg halide, to give the corresponding arylmagnesium chloride, b) reacting the latter with a borate of the formula B(OR′)3and hydrolyzing the product, with removal of the aldehyde protecting group, c) and, if desired, oxidizing or reducing the free aldehyde group.
A convergent asymmetric synthesis of a growth hormone secretagogue
Zheng, Nan,Armstrong III, Joseph D.,Eng, Kan K.,Keller, Jennifer,Liu, Tom,Purick, Robert,Lynch, Joseph,Hartner, Frederick W.,Volante
, p. 3435 - 3446 (2007/10/03)
Described herein is a convergent asymmetric synthesis of growth hormone secretagogue (GHS) suitable for large-scale preparations. Key features include: (1) an improved method for α-iodination of a lactam; (2) a novel synthesis of a disubstituted urea usin
Zinc borates: Functionalized hard nucleophiles for coupling reactions with secondary allylic acetates
Kobayashi, Yuichi,Tokoro, Yuko,Watatani, Kengo
, p. 3825 - 3834 (2007/10/03)
We have succeeded in developing zinc borates of the general structure 3 for coupling reaction with allylic acetates. The advantages of using compounds 3 are their compatibility with carbonyl groups such as aldehyde, ketone, and ester groups, and their high reactivity toward secondary allylic acetates. Zinc borates 3 were prepared from boronate esters 1 [R(T) = p-(CHO)C6H4, p-(Ac)C6H4, p-{Ac(CH2)2}C6H4, p-(Ac-OCH2)C6H4, p-{AcO(CH2)3}C6H4, p-{EtO2C(CH2}2}C6H4, (E)-CH=CH(CH2)4OAc] with MeZnCl; subsequent treatment with allylic acetates 4 [R = n-C5H11, c-C6H11, (CH2)2CH(-O(CH2}2O-)] in the presence of NiCl2(PPh3)2 (10 mol-%) in THF-DMI (1,3-dimethyl-2-imidazolidinone) (10 equiv.) at 40-50 °C overnight furnished the coupling products 5 in good yields. Among the products, 5bb, possessing one free and one protected aldehyde group, is a highlight of this type of reaction. The stereochemical aspects of the reaction were also examined. Thus, the alkenyl groups of (E)- and (Z)-alkenyl borates 3b and c were transformed with retention of the olefinic geometry into acetates 4a and b (R = n-C5H11, c-C6H11), while reaction of cyclic acetate 11 proceeded with inversion at the carbon center involved in the reaction. In addition, we found that the anions generated from (EtO)2P(= O)CH2CO2Et and (MeO)2P(=O)CH2Ac under Masamune's conditions attacked the aldehyde carbon in the boronate 1d to produce - after reduction of the double bond - the boronate esters 1i and 1j, respectively, in good yields.
