- Nickel-Catalyzed Ipso-Borylation of Silyloxyarenes via C-O Bond Activation
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The conversion of silyloxyarenes to boronic acid pinacol esters via nickel catalysis is described. In contrast to other borylation protocols of inert C-O bonds, the method is competent in activating the carbon-oxygen bond of silyloxyarenes in isolated aromatic systems lacking a directing group. The catalytic functionalization of benzyl silyl ethers was also achieved under these conditions. Sequential cross-coupling reactions were achieved by leveraging the orthogonal reactivity of silyloxyarenes, which could then be functionalized subsequently.
- Pein, Wesley L.,Wiensch, Eric M.,Montgomery, John
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supporting information
(2021/06/28)
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- Extremely facile formation of the pavine alkaloid skeleton by the photoreaction between isoquinoline and benzyltrifluoroborate
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Appling the photo-benzylation of isoquinoline with benzyltrifluoroborate, an extremely facile method for the construction of a pavine alkaloid skeleton was developed. When 3-methoxybenzylboron reagents were employed to the reaction, it was found that not
- Nishigaichi, Yutaka,Ohmuro, Yuuki,Hori, Yoshiki,Ohtani, Takuya
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supporting information
p. 118 - 120
(2020/02/25)
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- Method for synthesizing alkylborate compound
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The invention discloses a method for synthesizing an alkylborate compound, and concretely relates to a method for synthesizing the alkylborate compound through a cross-coupling reaction of chloralkaneand bis(pinacolato)diboron in the presence of metallic magnesium with Fe(acac)3 (acac = an acetylacetonate group) as a single component catalyst. The method for synthesizing the alkylborate compoundavoids the use of sensitive metal organic solvents and multi-component catalysts, realizes bilateral utilization of the bis(pinacolato)diboron, greatly reduces the use amount of the bis(pinacolato)diboron, and allows the coupling reaction of the cheap and easily-available chloralkane to be smoothly carried out under mild conditions; and compared with methods reported in literatures, the method disclosed in the invention has a better atom economy, a same or higher catalysis efficiency and a wider substrate applicability.
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Paragraph 0020
(2018/05/01)
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- Synthesis of Benzyl-, Allyl-, and Allenyl-boronates via Copper-Catalyzed Borylation of Alcohols
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Alcohols are among the most abundant and readily available organic feedstocks in industrial processes. The direct catalytic functionalization of sp3 C-O bonds of alcohols remains the main challenge in this field. Here, we report a copper-cataly
- Mao, Lujia,Szabó, Kálmán J.,Marder, Todd B.
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supporting information
p. 1204 - 1207
(2017/03/14)
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- Benzyltriboronates: Building Blocks for Diastereoselective Carbon-Carbon Bond Formation
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A highly diastereoselective carbon-carbon bond-forming reaction involving the tandem coupling of benzyltriboronates, enoates, and alkyl halides is described. This method was enabled by the discovery of α-diimine nickel catalysts that promote the chemosele
- Palmer, W. Neil,Zarate, Cayetana,Chirik, Paul J.
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p. 2589 - 2592
(2017/03/01)
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- Preparation method of benzyl boron ester compound
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The invention discloses a preparation method of a benzyl boron ester compound. According to the preparation method, aromatic boric acid Ar-B(OH)2, trimethyl silicon-based diazomethane, pinacol and tetrabutyl ammonium fluoride are subjected to a reaction in an organic solvent so as to obtain a benzyl pinacol boron ester compound, wherein Ar represents a non-heterocyclic aromatic group. After the method is adopted, the benzyl boron ester compound is obtained by starting from the aromatic boric acid and converting under a one-pot condition; the method is mild in reaction conditions, the reaction related to the method occurs smoothly in the air without needing strict water-free and oxygen-free conditions, and the method is convenient and simple to operate; the method has better tolerance and universality for functional groups and does not need an expensive metal catalyst and a ligand, thus being lower in reaction cost and being widely used for preparing the benzyl boron ester compound.
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Paragraph 0112; 0113; 0114; 0115; 0116; 0117
(2017/06/02)
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- Pd-catalyzed cross-coupling of 1,1-diborylalkanes with aryl triflates
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The Pd-catalyzed synthesis of benzylboronic esters through coupling of aryl triflates with 1,1-diborylalkane under ambient conditions is described. Varieties of primary and secondary arylboronic esters could be successfully synthesized by this strategy. C
- Cui, Long-Can,Zhang, Zhen-Qi,Lu, Xi,Xiao, Bin,Fu, Yao
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p. 51932 - 51935
(2016/06/13)
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- Iridium-Catalyzed Borylation of Primary Benzylic C-H Bonds without a Directing Group: Scope, Mechanism, and Origins of Selectivity
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Primary benzylic boronate esters are useful intermediates in organic synthesis, but these reagents cannot be prepared by hydroboration. The benzylic C-H borylation of methylarenes would be a method to form these products, but such reactions without neat methylarene or a directing group are unknown. We report an approach to divert the borylation of methylarenes from aromatic positions to benzylic positions with a silylborane as reagent and a new iridium catalyst containing an electron-deficient phenanthroline as ligand. This system forms benzylic boronate esters selectively over the corresponding aryl boronate esters. An Ir diboryl monosilyl complex ligated by the phenanthroline was isolated and determined to be the resting state of the catalyst. Mechanistic studies show that this complex is kinetically competent to be an intermediate in the catalytic process. Kinetic studies of benzylic and aryl C-H borylation catalyzed by various Ir complexes show that the rate of aryl C-H borylation decreases with decreasing electron density at the metal center of the Ir catalyst, but that the rate of benzylic C-H borylation is less sensitive to the degree of electron density at the metal center of the Ir catalyst. Kinetic and computational studies suggest that the two borylation reactions respond differently to the degree of electron density at the metal center because they occur with different turnover-limiting steps. The turnover-limiting step in the borylation of aryl C-H bonds is known to be C-H oxidative addition, but the turnover-limiting step of the borylation of benzylic C-H bonds appears to be an isomerization prior to C-B reductive elimination.
- Larsen, Matthew A.,Wilson, Conner V.,Hartwig, John F.
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supporting information
p. 8633 - 8643
(2015/07/15)
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- METHODS FOR PRODUCING BORYLATED ARENES
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Methods for the borylation of aromatic compounds using cobalt catalysts are provided.
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Paragraph 0359
(2015/12/30)
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- Iron-catalyzed borylation of alkyl, allyl, and aryl halides: Isolation of an iron(I) boryl complex
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Activation of B2pin2 with tBuLi facilitates the Fe-catalyzed borylation of alkyl, allyl, benzyl, and aryl halides via the formation of Li[B2pin2(tBu)] (1). The reaction of 1 with a representative iron phosphine precatalyst generates the unique iron(I) boryl complex [Fe(Bpin)(dpbz)2] (2).
- Bedford, Robin B.,Brenner, Peter B.,Carter, Emma,Gallagher, Timothy,Murphy, Damien M.,Pye, Dominic R.
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p. 5940 - 5943
(2015/01/08)
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- PYRROLOTRIAZINONE DERIVATIVES AS PI3K INHIBITORS
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New pyrrolotriazinone derivatives having the chemical structure of formula (I) are disclosed; as well as process for their preparation, pharmaceutical compositions comprising them and their use in therapy as inhibitors of Phosphoinositide 3-Kinases (PI3Ks).
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Page/Page column 97-98
(2014/05/07)
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- Transition-metal-free synthesis of pinacol alkylboronates from tosylhydrazones
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Highly efficient: Pinacol alkylboronates were synthesized by the reaction of tosylhydrazones with bis(pinacolato)diboron or pinacolborane under transition-metal-free conditions. This reaction represents an expeditious conversion of carbonyl functionality into a boronate group. Copyright
- Li, Huan,Wang, Long,Zhang, Yan,Wang, Jianbo
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p. 2943 - 2946
(2012/04/18)
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- Chemoselective Suzuki coupling of diborylmethane for facile synthesis of benzylboronates
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The chemoselective Pd-catalyzed Suzuki-Miyaura cross-coupling reaction using a diborylmethane is reported. The use of an equimolar amount of base with a diborylmethane realized chemoselective coupling for the synthesis of various benzylboronate derivatives. Sterically hindered aryl bromides can give products in moderate to excellent yields.
- Endo, Kohei,Ohkubo, Takahiro,Shibata, Takanori
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supporting information; experimental part
p. 3368 - 3371
(2011/09/12)
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- Electrosynthesis of benzylboronic acids and esters
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A novel preparation of benzylboronic acids and esters is described by using an electrochemical reductive coupling reaction between benzylic halides and borating agents (trialkylborates or pinacolborane). The reaction is carried out at room temperature in DMF or THF with the use of a sacrificial magnesium anode in a single-compartment cell.
- Pintaric,Laza,Olivero,Du?ach
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p. 8031 - 8033
(2007/10/03)
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- Synthesis of benzylic boronates via palladium-catalyzed cross-coupling reaction of bis(pinacolato)diboron with benzylic halides
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The palladium cross-coupling reaction of benzyl halides with diboron 1 yielded structurally diverse pinacol benzylic boronates. Under these reaction conditions, sensitive functionalities such as esters and nitriles are tolerated and the benzylic boronates
- Giroux, André
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p. 233 - 235
(2007/10/03)
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