934558-31-3Relevant academic research and scientific papers
Engaging Ag(0) single atoms in silver(I) salts-mediated C-B and C-S coupling under visible light irradiation
Cui, Enxin,Guo, Lirong,Li, Haibin,Qiao, Dan,Tung, Chen-Ho,Wang, Yifeng
, p. 255 - 263 (2021/09/06)
Silver(I) salts were found active in the borylation and sulfenylation of aryl iodides under visible light irradiation. The optimized borylation protocol using AgF did not need any additive, operated under very mild conditions, and well tolerated a broad scope of substrates and boron sources. Formation of Ag(0) single atoms (AgSAs) during the borylation reactions was examined using high-angle annular dark field aberration-corrected scanning transmission electron microscope (HAADF AC-STEM) and electron paramagnetic resonance (EPR). The activities of the silver(I) salts were affected by the anions and could be associated with their abilities in formation of AgSAs during the reactions. Kinetic studies showed that the deiodination rate was linearly correlated with the loading of AgSAs, and hence AgSAs were the true catalytic centers for the 1e?-reduction of the C-I moieties. The oxidation state of AgSAs kept 0 in both the resting and the working states. A “work-in-tandem” mechanism involving AgSAs as the catalytic centers and AgNPs as the light absorber to achieve the borylation of aryl iodides under visible light irradiation is proposed. The current approach not only provides an alternative system for borylation and sulfenylation of aryl iodides, but also reveals a new activity of silver(I) salts involving AgSAs under visible light irradiation.
Visible-Light-Induced Organocatalytic Borylation of Aryl Chlorides
Zhang, Li,Jiao, Lei
supporting information, p. 9124 - 9128 (2019/06/17)
The preparation of arylboronates from unactivated aryl chlorides in a transition-metal-free manner is rather challenging. There are only few examples to achieve this goal by using ultraviolet irradiation. Based on the mechanistic understanding of the diboron/methoxide/pyridine reaction system, we achieved photoactivation of the in situ generated super electron donor and developed a visible-light-induced organocatalytic method for efficient borylation of unactivated aryl chlorides.
Photocatalyzed borylation using water-soluble quantum dots
Chandrashekar, Hediyala B.,Maji, Arun,Halder, Ganga,Banerjee, Sucheta,Bhattacharyya, Sayan,Maiti, Debabrata
supporting information, p. 6201 - 6204 (2019/06/07)
The synthesis of arylboronates by Sandmeyer-type reactions in the presence of water still remains a significant challenge. Herein, we report the use of water-soluble MPA-capped quantum dot (QD) photocatalysts for the borylation of diazonium salts in the presence of water. A biphasic system under mild acidic conditions remains critical to prevent decomposition and competitive disulphide bond formation. The present protocol offers a broader scope of substrates and borylating agents. Additionally, this catalytic system offers a significantly high turnover number (TON). The present methodology can effectively distinguish subtle reactivity differences between boronic acids and boronates. Mechanistic investigation suggests an excited-state electron transfer pathway.
Tris(trimethylsilyl)silylboronate Esters: Novel Bulky, Air- and Moisture-Stable Silylboronate Ester Reagents for Boryl Substitution and Silaboration Reactions
Yamamoto, Eiji,Shishido, Ryosuke,Seki, Tomohiro,Ito, Hajime
supporting information, p. 3019 - 3022 (2017/09/05)
New, bulky tris(trimethylsilyl)silylboronate pinacol and hexylene glycol esters ((TMS)3Si-B(pin) and (TMS)3Si-B(hg)) were prepared in 46 and 61% yields, respectively, by the reaction of tris(trimethylsilyl)silylpotassium with the corresponding boron electrophiles. Notably, these silylboronate esters exhibited high stability to air and silica gel and were applied to the transition-metal-free boryl substitution of aryl halides, providing the desired borylated products in high yields with excellent B:Si ratios (up to 96% yield, B/Si = 99/1). These new silylboronate esters were also applied to a sequential borylation/cross-coupling process with various aryl halides, as well as the base-mediated silaboration of styrene.
Preparation method of aryl borate ester and allyl borate ester
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Paragraph 0096-0100, (2017/07/12)
The invention discloses a preparation method of aryl borate ester and allyl borate ester. The method comprises the following step: under the catalytic action of pyridine or a derivative thereof, carrying out 1) or 2) to obtain substituted boric acid ester shown as a formula I-1 or a formula I-2: 1) a reaction of a halide, bi-boric acid ester and alkoxide; 2) a reaction of a halide and a bi-boric acid ester-alkoxide complex. The method is an efficient preparation method of the aryl borate ester and the allyl borate ester. In the preparation method provided by the invention, the inexpensive pyridine or the derivative thereof is taken as a catalyst instead of a transition metal catalyst, the reaction conditions are mild, the reaction yield is high, residues of trace transition metal in a boronation product are avoided, and the cost of an aryl and allyl borate ester synthesis reaction is lowered.
Pyridine-catalyzed radical borylation of aryl halides
Zhang, Li,Jiao, Lei
supporting information, p. 607 - 610 (2017/05/15)
A pyridine-catalyzed transition-metal-free borylation reaction of haloarenes has been developed based on the selective cross-coupling of an aryl radical and a pyridine-stabilized boryl radical. Arylboronates were produced from haloarenes under mild conditions. This borylation reaction features a broad substrate scope, operational simplicity, and gram-scale synthetic ability.
Base-Free Palladium-Catalyzed Borylation of Aryl Chlorides with Diborons
Yamamoto, Yutaro,Matsubara, Hiroshi,Yorimitsu, Hideki,Osuka, Atsuhiro
, p. 2317 - 2320 (2016/07/28)
The base-free palladium-catalyzed borylation of aryl chlorides with diborons was achieved. The base-free conditions offered acceptable functional group compatibility. Based on experimental and computational studies, it was shown that smooth boryl transfer from the diborons to the arylpalladium chloride was promoted by strong interaction between the Lewis acidic boron and the chlorine atom on palladium.
Nickel-Catalyzed Borylation of Aryl- and Benzyltrimethylammonium Salts via C-N Bond Cleavage
Hu, Jiefeng,Sun, Heqing,Cai, Wangshui,Pu, Xinghui,Zhang, Yemin,Shi, Zhuangzhi
, p. 14 - 24 (2016/01/15)
By developing a mild Ni-catalyzed system, a method for direct borylation of sp2 and sp3 C-N bonds has been established. The key to this hightly efficient C-N bond borylative cleavage depends on the appropriate choice of the nickel catalyst Ni(COD)2, ICy·HCl as a ligand, and the use of 2-ethoxyethanol as the cosolvent. This transformation shows good functional group compatibility and can serve as a powerful synthetic tool for gram-scale synthesis and late-stage C-N borylation of complex compounds.
The method for producing the phenyl boronic acid ester
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Paragraph 0123; 0124, (2018/09/26)
PROBLEM TO BE SOLVED: To provide a method for producing phenylboronic acid esters in good yield from diborons and aryl halides by using a nickel catalyst and a base. SOLUTION: In the method for producing phenylboronic acid esters represented by general formula (3), wherein A is an ethylene group or the like which may be substituted by a methyl group, R1is a fluorine atom or the like, and m is an integer of 0-5; diborons and a chlorobenzene derivative are reacted with each other by using a trimethylphosphine coordinated nickel catalyst and alkoxides. COPYRIGHT: (C)2013,JPOandINPIT
Nickel-catalyzed bolylation of aryl halides with 4,4,6-trimethyl-1,3,2- dioxaborinane
Murata, Miki,Sogabe, Yosuke,Namikoshi, Takeshi,Watanabe, Shinji
, p. 133 - 138 (2013/08/23)
The nickel-catalyzed borylation of aryl iodides and bromides with 4,4,6-trimethyl-1,3,2-dioxaborinane was achieved. The mild reaction conditions employed allowed for the inclusion of common functional groups in aryl halides to be tolerated. A DFT study on the catalytic cycle shows that C-B bond formation occurs through s-bond metathesis between dialkoxyborane and arylnickel(II) halide intermediates.
