126689-01-8Relevant articles and documents
Visible-light-driven graphene supported Cu/Pd alloy nanoparticle-catalyzed borylation of alkyl bromides and chlorides in air
Jiao, Zhi-Feng,Tian, Ya-Ming,Guo, Xiao-Ning,Radius, Udo,Braunschweig, Holger,Marder, Todd B.,Guo, Xiang-Yun
, p. 258 - 265 (2021)
A highly efficient photocatalytic protocol for borylation of alkyl bromides and chlorides with graphene supported Cu/Pd alloy nanoparticles as a heterogeneous catalyst is reported. This photocatalytic system operates with visible light in air, providing a wide range of primary and secondary alkyl halides with B2pin2 or B2neop2 in high yields at low temperatures, thereby demonstrating its broad utility and functional group tolerance. The high performance is attributed to a synergistic effect of localized surface plasmon resonance (LSPR) of Cu and charge transfer from Cu to Pd due to the alloy surface charge heterogeneity. Transfer of energetic electrons from Pd to electrophilic alkyl halides lead to the formation of the alkyl radicals, which quickly react with a nucleophilic adduct of a diboron compound with base adsorbed on the positively charged Cu sites to form the corresponding borylation product.
Visible-light-mediated borylation of aryl and alkyl halides with a palladium complex
Zhao, Jia-Hui,Zhou, Zhao-Zhao,Zhang, Yue,Su, Xuan,Chen, Xi-Meng,Liang, Yong-Min
supporting information, p. 4390 - 4394 (2020/10/20)
Palladium catalyzed visible-light-mediated borylation of inactivated aryl and alkyl halides is reported; the method provided high yields and excellent functional group compatibility. Furthermore, arylsilicates were synthesized selectively using dimethylphenylsilyl boronic ester via changing the reaction conditions. Finally, the possible reaction mechanism is determined through fluorescence quenching and turn on/off experiments.
Hydrogen Atom Transfer Induced Boron Retaining Coupling of Organoboronic Esters and Organolithium Reagents
Wang, Dinghai,Mück-Lichtenfeld, Christian,Studer, Armido
supporting information, p. 14126 - 14130 (2019/10/11)
α-Functionalization of alkyl boronic esters and homologation of aryl boronic esters by regioselective radical C(sp3)-H activation in boron-ate complexes is reported. Reaction of commercial or readily accessed aryl boronic acid pinacol esters with alkyl lithium reagents provides boron-ate complexes. Selective α-C-H abstraction by in situ generated trifluoromethyl radicals leads to radical anions that undergo electron transfer oxidation followed by 1,2-aryl/alkyl migration from boron to carbon to give the α-arylated/alkylated alkyl boronic esters. The valuable boronic ester functionality remains in the products and the cheap trifluoromethyl iodide acts as the oxidant in these C-C couplings. The 1,2-alkyl migration from boron to carbon is highly stereospecific allowing access to stereoisomerically pure boronic esters.
One-pot synthesis process for producing boron compounds
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Paragraph 0036-0038, (2018/10/19)
The invention discloses a one-pot synthesis process for boron-amine compounds. The process comprises the steps of slowly dripping an anhydrous solvent, bromo-compounds RBr and XBY2 which are mixed into the anhydrous solvent containing metal lithium, maintaining the temperature at -20 to 20 DEG C in a dripping process, maintaining the temperature of -20 to 40 DEG C and reacting for 3-8h after the reaction initiation and the completion of adding the rest mixed solution, and separating to obtain the RBY2. An intermediate can be added with acid to be hydrolyzed to obtain organic boric acid, and reacted with diol to generate boric acid ester, or is directly conducted for coupled reaction with an aryl halogenate. The process is simple in process, few in by-product and high in reaction yield, and the ultralow temperature reaction and the dependency on the solvent by the stability of lithiated compounds can be prevented, therefore the process is applicable to industrial amplification and is beneficial for improving the core competitiveness of products.
One-Pot, Three-Step Synthesis of Cyclopropylboronic Acid Pinacol Esters from Synthetically Tractable Propargylic Silyl Ethers
Spencer, Jonathan A.,Jamieson, Craig,Talbot, Eric P. A.
supporting information, p. 3891 - 3894 (2017/07/26)
Simple propargylic silyl ethers can be converted to complex cyclopropylboronic acid pinacol esters in an efficient one-pot procedure. Terminal acetylenes undergo a Schwartz's reagent catalyzed hydroboration; subsequent addition of further Schwartz's reage
Highly efficient synthesis of alkylboronate esters via Cu(II)-Catalyzed borylation of unactivated alkyl bromides and chlorides in air
Bose, Shubhankar Kumar,Brand, Simon,Omoregie, Helen Oluwatola,Haehnel, Martin,Maier, Jonathan,Bringmann, Gerhard,Marder, Todd B.
, p. 8332 - 8335 (2018/05/22)
A copper(II)-catalyzed borylation of alkyl halides with bis(pinacolato)diboron (B2pin2) has been developed, which can be carried out in air, providing a wide range of primary, secondary, and some tertiary alkylboronates in high yields. A variety of functional groups are tolerated and the protocol is also applicable to unactivated alkyl chlorides (including 1,1- and 1,2-dichlor-ides). Preliminary mechanistic investigations show that this borylation reaction involves one-electron processes.
A general method for interconversion of boronic acid protecting groups: Trifluoroborates as common intermediates
Churches, Quentin I.,Hooper, Joel F.,Hutton, Craig A.
, p. 5428 - 5435 (2015/06/16)
We have developed a general protocol for the interconversion of diverse protected boronic acids, via intermediate organotrifluoroborates. N-Methyliminodiacetyl boronates, which have been hitherto resistant to direct conversion to trifluoroborates, have been shown to undergo fluorolysis at elevated temperatures. Subsequent solvolysis of organotrifluoroborates in the presence of trimethylsilyl chloride and a wide range of bis-nucleophiles enables the generation of a variety of protected boronic acids.
Zinc-catalyzed borylation of primary, secondary and tertiary alkyl halides with alkoxy diboron reagents at room temperature
Bose, Shubhankar Kumar,Fucke, Katharina,Liu, Lei,Steel, Patrick G.,Marder, Todd B.
supporting information, p. 1799 - 1803 (2014/03/21)
A new catalytic system based on a ZnII NHC precursor has been developed for the cross-coupling reaction of alkyl halides with diboron reagents, which represents a novel use of a Group XII catalyst for C=X borylation. This approach gives borylations of unactivated primary, secondary, and tertiary alkyl halides at room temperature to furnish alkyl boronates, with good functional-group compatibility, under mild conditions. Preliminary mechanistic investigations demonstrated that this borylation reaction seems to involve one-electron processes. Coupling a la carte: A catalytic system based on a ZnII N-heterocyclic carbene precursor has been developed for the cross-coupling reaction of alkyl halides with diboron reagents (see scheme). This is a novel use of a Group 12 catalyst for C=X borylation. IMes=1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene. Copyright
Alkylboronic esters from copper-catalyzed borylation of primary and secondary alkyl halides and pseudohalides
Yang, Chu-Ting,Zhang, Zhen-Qi,Tajuddin, Hazmi,Wu, Chen-Cheng,Liang, Jun,Liu, Jing-Hui,Fu, Yao,Czyzewska, Maria,Steel, Patrick G.,Marder, Todd B.,Liu, Lei
supporting information; experimental part, p. 528 - 532 (2012/02/04)
Easy access: An unprecedented copper-catalyzed cross-coupling reaction of the title compounds with diboron reagents is described (see scheme; Ts=4-toluenesulfonyl). This reaction can be used to prepare both primary and secondary alkylboronic esters having diverse structures and functional groups. The resulting products would be difficult to access by other means. Copyright
