- A new polymorph of tetra-phenyl-diboroxane
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A new polymorph of tetra-phenyl-diboroxane [or oxybis(diphenyl-borane)], C24H20B2O, (Ia), has been found. It is monoclinic, like the already known form, (Ib), and can be refined in the same space group, namely P21/c, or in the equivalent setting P21/n. Th
- Kaufmann, Linda,Lerner, Hans-Wolfram,Bolte, Michael
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- A new photoisomerization process of the 4-cyanobutyl group in a cobaloxime complex crystal observed by neutron diffraction
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The 4-cyanobutyl group of (4-cyanobutyl)[3,4-lutidine](dimethylglyoximato) [O-(diphenylboryl)dimethylglyoximato] cobalt(III) was isomerized to the 1-cyanobutyl group with retention of the single-crystal form, although the corresponding cobaloxime complex
- Hosoya, Takaaki,Uekusa, Hidehiro,Ohashi, Yuji,Ohhara, Takashi,Kuroki, Ryota
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- Bright and Stable NIR-II J-Aggregated AIE Dibodipy-Based Fluorescent Probe for Dynamic In Vivo Bioimaging
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Organic dyes emitting in the second near-infrared (NIR-II, 900–1700 nm) window, with high molar extinction coefficients (MEC) and quantum yields (QY) in aqueous, are essential for in vivo bioimaging and biosensing. In this work, we developed a dibodipy-based aggregation-induced emission (AIE) fluorescent probe, THPP, to meet this aim. THPP exhibits a high MEC and has intensified absorption and emission in J-aggregated state, which significantly enhance the fluorescence intensity (≈55 folds) and extend the maximal absorption/emission wavelengths to 970/1010 nm in NIR-II region. Based on the bright THPP, imaging with a high frame rate (34 frames per second) at a deep “valid penetration depth” up to 6 mm can be achieved. This enabled simultaneous and dynamic imaging of vasculatures and deep tissues. Besides, we succeeded in monitoring the respiratory rate of acute-lung-injury mice and tracing the collateral circulation process with a high frame rate.
- Zhang, Qisong,Yu, Peng,Fan, Yong,Sun, Caixia,He, Haisheng,Liu, Xuan,Lu, Lingfei,Zhao, Mengyao,Zhang, Hongxin,Zhang, Fan
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supporting information
p. 3967 - 3973
(2020/12/25)
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- Mechanism of an Organoboron-Catalyzed Domino Reaction: Kinetic and Computational Studies of Borinic Acid-Catalyzed Regioselective Chloroacylation of 2,3-Epoxy Alcohols
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A mechanistic study of the borinic acid-catalyzed chloroacylation of 2,3-epoxy alcohols is presented. In this unusual mode of catalysis, the borinic acid activates the substrate toward sequential reactions with a nucleophile (epoxide ring-opening by chloride) and an electrophile (O-acylation of the resulting alkoxide). Reaction progress kinetic analysis of data obtained through in situ FTIR spectroscopy is consistent with a mechanism involving turnover-limiting acylation of a chlorohydrin-derived borinic ester. This proposal is further supported by investigations of the effects of aroyl chloride substitution on reaction rate. The kinetics experiments also shed light on the effects of chloride concentration on reaction rate and indicate that the catalyst is subject to inhibition by the product of the chloroacylation reaction. Computational modeling is employed to gain insight into the effects of the organoboron catalyst on the regioselectivities of the epoxide ring-opening and acylation steps. The density functional theory calculations provide a plausible pathway for selective chlorinolysis at C-3 and benzoylation at O-1, as is observed experimentally.
- Garrett, Graham E.,Tanveer, Kashif,Taylor, Mark S.
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p. 1085 - 1095
(2018/06/18)
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- BORON-BASED CYCLOADDITION CATALYSTS AND METHODS FOR THE PRODUCTION OF BIO-BASED TEREPHTHALIC ACID, ISOPHTHALIC ACID AND POLY (ETHYLENE TEREPHTHALATE)
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Methods for producing cycloaddition products comprising: reacting a diene with a dienophile in the presence of one or more boron-based catalysts of Formula I or Formula II are provided. In particular, the methods can be used to prepare 4-methyl-3-cyclohexene- 1-carboxylic acid and 3-methyl-3-cyclohexene-l-carboxylic acid, including bio-based versions thereof. The cycloaddition products can be advantageously used in the production of terephthalic acid and isophthalic acid, and ultimately, poly(ethylene terephthalate), and bio-based versions thereof. Formula I Formula II
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Paragraph 00163; 00164; 00165
(2017/04/11)
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- Cross-coupling of diarylborinic acids and anhydrides with arylhalides catalyzed by a phosphite/N-heterocyclic carbene co-supported palladium catalyst system
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A highly efficient cross-coupling of diarylborinic acids and anhydrides with aryl chlorides and bromides has been effected by using a palladium catalyst system co-supported by a strong σ-donor N-heterocyclic carbene (NHC), N,N′-bis(2,6-diisopropylphenyl) imidazol-2-ylidene, and a strong π-acceptor phosphite, triphenylphosphite, in tert-BuOH in the present of K3PO4·3H2O. Unsymmetrical biaryls with a variety of functional groups could be obtained in good to excellent yields using as low as 0.01, 0.2-0.5, and 1 mol % palladium loadings for aryl bromides and activated and deactivated aryl chlorides, respectively, under mild conditions. A ligand synergy between the σ-donor NHC and the π-acceptor phosphite in the Pd/NHC/P(OPh)3 catalytic system has been proposed to be responsible for the high efficacy to arylchlorides in the cross-coupling. A scalable and economical process has therefore been developed for synthesis of Sartan biphenyl from the Pd/NHC/P(OPh)3 catalyzed cross-coupling of di(4-methylphenyl)borinic acid with 2-chlorobenzonitrile.
- Chen, Xiaofeng,Ke, Haihua,Chen, Yao,Guan, Changwei,Zou, Gang
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p. 7572 - 7578
(2012/10/29)
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- A novel transmetallation of triarylstibanes into arylboronate: Boro-induced ipso-deantimonation and its theoretical calculation
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Treatment of triarylstibanes with boron trichloride followed by derivatization with methanol and 1,3-propanediol afforded arylboronates in good yield with all three aryl groups on the antimony being utilized. Theoretical calculation of the reaction pathwa
- Yasuike, Shuji,Nakata, Kazuhide,Qin, Weiwei,Kaji, Toshiyuki,Kurita, Jyoji
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p. 1402 - 1403
(2007/10/03)
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- Insertion of an osmium nitride into boron-carbon bonds
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When arylboranes react with the osmium(VI) nitrido complex [{HB(pz)3}Os(N)Cl2)], they do not just bind to the nitrogen atom. A B-C bond is cleaved, and the phenyl and boryl units are separately bound to nitrogen in the product (e.g. 1; X = Ph; Y = Ph, OBPh2). Subsequent hydrolysis leads to cleavage of the B-N bond and generation of the anilido species ({HB(pz)3}Os(NHPh)Cl2]. pz = pyrazolyl.
- Crevier, Thomas J.,Mayer, James M.
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p. 1891 - 1893
(2007/10/03)
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