- Selective Benzylic CH-Borylations by Tandem Cobalt Catalysis
-
Metal-catalyzed C?H activations are environmentally and economically attractive synthetic strategies for the construction of functional molecules as they obviate the need for pre-functionalized substrates and minimize waste generation. Great challenges reside in the control of selectivities, the utilization of unbiased hydrocarbons, and the operation of atom-economical dehydrocoupling mechanisms. An especially mild borylation of benzylic CH bonds was developed with the ligand-free pre-catalyst Co[N(SiMe3)2]2 and the bench-stable and inexpensive borylation reagent B2pin2 that produces H2 as the only by-product. A full set of kinetic, spectroscopic, and preparative mechanistic studies are indicative of a tandem catalysis mechanism of CH-borylation and dehydrocoupling via molecular CoI catalysts.
- Bauer, Matthias,Ghosh, Pradip,Jacobi von Wangelin, Axel,Schoch, Roland
-
supporting information
(2021/11/27)
-
- Practical Synthesis of Allyl, Allenyl, and Benzyl Boronates through SN1′-Type Borylation under Heterogeneous Gold Catalysis
-
Efficient borylation of sp3 C-O bonds by supported Au catalysts is described. Au nanoparticles supported on TiO2 showed high activity under mild conditions employing low catalyst loading conditions without the aid of any additives, such as phosphine and bases. A variety of allyl, propargyl, and benzyl substrates participated in the heterogeneously catalyzed reactions to furnish the corresponding allyl, allenyl, and benzyl boronates in high yields. Besides, Au/TiO2 was also effective for the direct borylation of allylic and benzylic alcohols. A mechanistic investigation based on a Hammett study and control experiments revealed that sp3 C-O bond borylation over supported Au catalysts proceeded through SN1′-type mechanism involving the formation of a carbocationic intermediate. The high activity, reusability, and environmental compatibility of the supported Au catalysts as well as the scalability of the reaction system enable the practical synthesis of valuable organoboron compounds.
- Miura, Hiroki,Hachiya, Yuka,Nishio, Hidenori,Fukuta, Yohei,Toyomasu, Tomoya,Kobayashi, Kosa,Masaki, Yosuke,Shishido, Tetsuya
-
p. 758 - 766
(2021/02/03)
-
- C(sp3)-H selective benzylic borylation by in situ reduced ultrasmall Ni species on CeO2
-
Herein, we report that highly dispersed Ni hydroxide species supported on CeO2 act as an efficient heterogeneous catalyst for the selective borylation of benzylic C(sp3)-H bonds of alkylarenes including secondary derivatives, using pinacolborane as the bo
- Yoshii, Daichi,Yatabe, Takafumi,Yabe, Tomohiro,Yamaguchi, Kazuya
-
p. 2150 - 2155
(2021/02/20)
-
- (o-Phenylenediamino)borylstannanes: Efficient Reagents for Borylation of Various Alkyl Radical Precursors
-
(o-Phenylenediamino)borylstannanes were newly synthesized to achieve radical boryl substitutions of a variety of alkyl radical precursors. Dehalogenative, deaminative, decharcogenative, and decarboxylative borylations proceeded in the presence of a radica
- Suzuki, Kensuke,Nishimoto, Yoshihiro,Yasuda, Makoto
-
p. 3968 - 3973
(2020/12/30)
-
- Extremely facile formation of the pavine alkaloid skeleton by the photoreaction between isoquinoline and benzyltrifluoroborate
-
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
-
supporting information
p. 118 - 120
(2020/02/25)
-
- Deoxygenative Borylation of Secondary and Tertiary Alcohols
-
Two different approaches for the deoxygenative radical borylation of secondary and tertiary alcohols are presented. These transformations either proceed through a metal-free silyl-radical-mediated pathway or utilize visible-light photoredox catalysis. Readily available xanthates or methyl oxalates are used as radical precursors. The reactions show broad substrate scope and high functional-group tolerance, and are conducted under mild and practical conditions.
- Friese, Florian W.,Studer, Armido
-
supporting information
p. 9561 - 9564
(2019/06/21)
-
- Nickel-Catalyzed 1,1-Alkylboration of Electronically Unbiased Terminal Alkenes
-
An unprecedented nickel-catalyzed 1,1-alkylboration of electronically unbiased alkenes has been developed, providing straightforward access to secondary aliphatic boronic esters from readily available materials under very mild reaction conditions. The regioselectivity of this reaction is governed by a unique pyridyl carboxamide ligated catalyst, rather than the substrates. Moreover, this transformation shows excellent chemo- and regio-selectivity and remarkably good functional-group tolerance. We also demonstrate that under balloon pressure, ethylene can also be utilized as a substrate. Additionally, competence experiments indicate that selective bond formation is favored at the α-position of boron and preliminary mechanistic studies indicate that the key step in this three-component reaction involves a 1,2-nickel migration.
- Li, Yangyang,Pang, Hailiang,Wu, Dong,Li, Zheqi,Wang, Wang,Wei, Hong,Fu, Ying,Yin, Guoyin
-
supporting information
p. 8872 - 8876
(2019/05/28)
-
- Rapid Assessment of the Reaction-Condition-Based Sensitivity of Chemical Transformations
-
A systematic, user-friendly assessment tool that delivers a clear overview of the sensitivity of reactions to key parameters is highly desirable. Herein, the development of such a method is described. The intuitive, standardized presentation of the result
- Pitzer, Lena,Sch?fers, Felix,Glorius, Frank
-
p. 8572 - 8576
(2019/05/28)
-
- Structure-based development of (1-(3′-Mercaptopropanamido)methyl)boronic Acid Derived Broad-Spectrum, Dual-Action Inhibitors of Metallo- And Serine-β-lactamases
-
The emergence and spread of bacterial pathogens acquired metallo-β-lactamase (MBL) and serine-β-lactamase (SBL) medicated β-lactam resistance gives rise to an urgent need for the development of new dual-action MBL/SBL inhibitors. Application of a pharmacophore fusion strategy led to the identification of (2′S)-(1-(3′-mercapto-2′-methylpropanamido)methyl)boronic acid (MS01) as a new dual-action inhibitor, which manifests broad-spectrum inhibition to representative MBL/SBL enzymes, including the widespread VIM-2 and KPC-2. Guided by the VIM-2:MS01 and KPC-2:MS01 complex structures, further structural optimization yielded new, more potent dual-action inhibitors. Selectivity studies indicated that the inhibitors had no apparent inhibition to human angiotensin-converting enzyme-2 and showed selectivity across serine hydrolyases in E. coli and human HEK293T cells labeled by the activity-based probe TAMRA-FP. Moreover, the inhibitors displayed potentiation of meropenem efficacy against MBL- or SBL-positive clinical isolates without apparent cytotoxicity. This work will aid efforts to develop new types of clinically useful dual-action inhibitors targeting MBL/SBL enzymes.
- Wang, Yao-Ling,Liu, Sha,Yu, Zhu-Jun,Lei, Yuan,Huang, Meng-Yi,Yan, Yu-Hang,Ma, Qiang,Zheng, Yang,Deng, Hui,Sun, Ying,Wu, Chengyong,Yu, Yamei,Chen, Qiang,Wang, Zhenling,Wu, Yong,Li, Guo-Bo
-
p. 7160 - 7184
(2019/08/28)
-
- Method for synthesizing alkylborate compound
-
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.
- -
-
Paragraph 0022
(2018/05/01)
-
- Deaminative Borylation of Aliphatic Amines Enabled by Visible Light Excitation of an Electron Donor–Acceptor Complex
-
A deaminative strategy for the borylation of aliphatic primary amines is described. Alkyl radicals derived from the single-electron reduction of redox-active pyridinium salts, which can be isolated or generated in situ, were borylated in a visible light-mediated reaction with bis(catecholato)diboron. No catalyst or further additives were required. The key electron donor–acceptor complex was characterized in detail by both experimental and computational investigations. The synthetic potential of this mild protocol was demonstrated through the late-stage functionalization of natural products and drug molecules.
- Sandfort, Frederik,Strieth-Kalthoff, Felix,Klauck, Felix J. R.,James, Michael J.,Glorius, Frank
-
supporting information
p. 17210 - 17214
(2018/11/10)
-
- Visible-Light-Mediated Aerobic Oxidation of Organoboron Compounds Using in Situ Generated Hydrogen Peroxide
-
A simple and general visible-light-mediated oxidation of organoboron compounds has been developed with rose bengal as the photocatalyst, substoichiometric Et3N as the electron donor, as well as air as the oxidant. This mild and metal-free protocol shows a broad substrate scope and provides a wide range of aliphatic alcohols and phenols in moderate to excellent yields. Notably, the robustness of this method is demonstrated on the stereospecific aerobic oxidation of organoboron compounds.
- Weng, Wei-Zhi,Liang, Hao,Zhang, Bo
-
supporting information
p. 4979 - 4983
(2018/08/24)
-
- IMMUNOPROTEASOME INHIBITORS
-
Provided herein are compounds, such as a compound of Formula (I), as described herein, or a pharmaceutically acceptable salt thereof, that are immunoproteasome (such as LMP2 and LMP7) inhibitors. The compounds described herein can be useful for the treatment of diseases treatable by inhibition of immunoproteasomes. Also provided herein are pharmaceutical compositions containing such compounds and processes for preparing such compounds.
- -
-
Paragraph 0365
(2018/08/20)
-
- STABILIZATION OF ACTIVE METAL CATALYSTS AT METAL-ORGANIC FRAMEWORK NODES FOR HIGHLY EFFICIENT ORGANIC TRANSFORMATIONS
-
Metal-organic framework (MOFs) compositions based on post?synthetic metalation of secondary building unit (SBU) terminal or bridging OH or OH2 groups with metal precursors or other post-synthetic manipulations are described. The MOFs provide a versatile family of recyclable and reusable single-site solid catalysts for catalyzing a variety of asymmetric organic transformations, including the regioselective boryiation and siiylation of benzyiic C—H bonds, the hydrogenation of aikenes, imines, carbonyls, nitroarenes, and heterocycles, hydroboration, hydrophosphination, and cyclization reactions. The solid catalysts can also be integrated into a flow reactor or a supercritical fluid reactor.
- -
-
Paragraph 0238; 0243
(2019/01/07)
-
- Synthesis of Benzyl-, Allyl-, and Allenyl-boronates via Copper-Catalyzed Borylation of Alcohols
-
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.
-
supporting information
p. 1204 - 1207
(2017/03/14)
-
- Metal-organic layers stabilize earth-abundant metal-terpyridine diradical complexes for catalytic C-H activation
-
We report the synthesis of a terpyridine-based metal-organic layer (TPY-MOL) and its metalation with CoCl2 and FeBr2 to afford CoCl2·TPY-MOL and FeBr2·TPY-MOL, respectively. Upon activation with NaEt3
- Lin, Zekai,Thacker, Nathan C.,Sawano, Takahiro,Drake, Tasha,Ji, Pengfei,Lan, Guangxu,Cao, Lingyun,Liu, Shubin,Wang, Cheng,Lin, Wenbin
-
p. 143 - 151
(2018/01/02)
-
- Unveiling the role of boroxines in metal-free carbon-carbon homologations using diazo compounds and boronic acids
-
By means of computational and experimental mechanistic studies the fundamental role of boroxines in the reaction between diazo compounds and boronic acids was elucidated. Consequently, a selective metal-free carbon-carbon homologation of aryl and vinyl boroxines using TMSCHN2, giving access to TMS-pinacol boronic ester products, was developed.
- Bomio, Claudio,Kabeshov, Mikhail A.,Lit, Arthur R.,Lau, Shing-Hing,Ehlert, Janna,Battilocchio, Claudio,Ley, Steven V.
-
p. 6071 - 6075
(2017/08/29)
-
- Benzyltriboronates: Building Blocks for Diastereoselective Carbon-Carbon Bond Formation
-
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.
-
p. 2589 - 2592
(2017/03/01)
-
- Preparation method of benzyl boron ester compound
-
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.
- -
-
Paragraph 0058; 0059; 0060; 0061; 0062; 0063
(2017/06/02)
-
- Pd-catalyzed cross-coupling of 1,1-diborylalkanes with aryl triflates
-
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
-
p. 51932 - 51935
(2016/06/13)
-
- Cobalt-Catalyzed Benzylic Borylation: Enabling Polyborylation and Functionalization of Remote, Unactivated C(sp3)-H Bonds
-
Cobalt dialkyl and bis(carboxylate) complexes bearing α-diimine ligands have been synthesized and demonstrated as active for the C(sp3)-H borylation of a range of substituted alkyl arenes using B2Pin2 (Pin = pinacolate) as the boron source. At longer reaction times, rare examples of polyborylation were observed, and in the case of toluene, all three benzylic C-H positions were functionalized. Coupling benzylic C-H activation with alkyl isomerization enabled a base-metal-catalyzed method for the borylation of remote, unactivated C(sp3)-H bonds.
- Palmer, W. Neil,Obligacion, Jennifer V.,Pappas, Iraklis,Chirik, Paul J.
-
supporting information
p. 766 - 769
(2016/02/05)
-
- Making Dimethylamino a Transformable Directing Group by Nickel-Catalyzed C-N Borylation
-
The dimethylamino (Me2N) group is arguably the most versatile functional group capable of highly efficient and site-selective directed aromatic functionalizations at the ortho-, meta-, and para-positions depending on reaction conditions. While the repertoire of Me2N-directed reactions is growing at a rapid pace, the lack of a general method to transform this group to other functionalities hampers its wider application in organic synthesis. Here we report nickel-catalyzed C-N borylations of aryl- and benzyl-dimethylamines that permit the conversion of a huge library of largely underutilized Me2N-containing organic molecules into various functional molecules by taking advantage of the wealth of existing C-B functionalization methods.
- Zhang, Hua,Hagihara, Shinya,Itami, Kenichiro
-
p. 16796 - 16800
(2015/11/16)
-
- Rhodium-catalyzed borylation of aryl 2-pyridyl ethers through cleavage of the carbon-oxygen bond: Borylative removal of the directing group
-
The rhodium-catalyzed reaction of aryl 2-pyridyl ethers with a diboron reagent results in the formation of arylboronic acid derivatives via activation of the C(aryl)-O bonds. The straightforward synthesis of 1,2-disubstituted arenes was enabled through catalytic ortho C-H bond functionalization directed by the 2-pyridyloxy group followed by substitution of this group with a boryl group. Several control experiments revealed that the presence of a sp2 nitrogen atom at the 2-position of the substrate and the use of a boron-based reagent were crucial for the activation of the relatively inert C(aryl)-O bond of aryl 2-pyridyl ethers.
- Kinuta, Hirotaka,Tobisu, Mamoru,Chatani, Naoto
-
p. 1593 - 1600
(2015/03/05)
-
- Iron-catalyzed borylation of alkyl electrophiles
-
The use of low-cost iron(III) acetoacetate (Fe(acac)3) and tetramethylethylenediamine (TMEDA) enables the direct cross-coupling of alkyl halides with bis(pinacolato)diboron. This approach allows for the borylation of activated or unactivated primary, secondary, and tertiary bromides. Moreover, even the borylation of benzylic or allylic chlorides, tosylates, and mesylates are possible. The reactions proceed under mild conditions at room temperature and show broad functional-group compatibility and "robustness" as measured by a modified Glorius robustness screen.
- Atack, Thomas C.,Lecker, Rachel M.,Cook, Silas P.
-
supporting information
p. 9521 - 9523
(2014/07/22)
-
- Silver(I) oxide-promoted chemoselective cross-coupling reaction of (Diborylmethyl)trimethylsilane
-
The present paper describes a synergistic effect in the Pdcatalyzed SuzukiMiyaura cross-coupling reaction. The chemoselective cross-coupling reaction of (diborylmethyl)trimethylsilane and aryl halides proceeded at room temperature when a silver salt and K
- Endo, Kohei,Kurosawa, Fumiya,Ukaji, Yutaka
-
supporting information
p. 1363 - 1365
(2013/11/19)
-
- Transition-metal-free synthesis of pinacol alkylboronates from tosylhydrazones
-
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
-
p. 2943 - 2946
(2012/04/18)
-
- Chemoselective Suzuki coupling of diborylmethane for facile synthesis of benzylboronates
-
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
-
supporting information; experimental part
p. 3368 - 3371
(2011/09/12)
-
- An opportunity for Mg-catalyzed grignard-type reactions: Direct coupling of benzylic halides with pinacolborane with 10 mol % of magnesium
-
Mg in catalytic amounts as the only metal permits the reductive coupling between benzyl halides and pinacolborane. HBpin acts both as an electrophile and as a reducing agent to regenerate an organomagnesium species in situ. An hydride oxidation mechanism is proposed on the basis of DFT calculations.
- Pintaric, Christine,Olivero, Sandra,Gimbert, Yves,Chavant, Pierre Y.,Dunach, Elisabet
-
supporting information; experimental part
p. 11825 - 11827
(2010/11/02)
-
- Electrosynthesis of benzylboronic acids and esters
-
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
-
p. 8031 - 8033
(2007/10/03)
-
- Synthesis of benzylic boronates via palladium-catalyzed cross-coupling reaction of bis(pinacolato)diboron with benzylic halides
-
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
-
p. 233 - 235
(2007/10/03)
-
- Synthesis of benzylboronates via palladium-catalyzed borylation of benzyl halides with pinacolborane
-
Various benzyl halides were borylated with pinacolborane in the presence of iPr2NEt and a catalytic amount of PdCl2(PPh3)2 to afford the corresponding benzylboronates in good yields.
- Murata, Miki,Oyama, Takashi,Watanabe, Shinji,Masuda, Yuzuru
-
p. 2513 - 2517
(2007/10/03)
-
- Nucleophilic borylation of benzyl halides with bis(pinacolato)diboron catalyzed by palladium(0) complexes
-
Nucleophilic borylation of benzyl halides with bis(pinacolato)diboron in the presence of KOAc in toluene was effectively catalyzed by a palladium complex generated in situ from Pd(dba)2 and (4-MeOC6H4)3P, giving the corresponding pinacol benzylboronates in high yields.
- Ishiyama, Tatsuo,Oohashi, Zengo,Ahiko, Taka-Aki,Miyaura, Norio
-
p. 780 - 781
(2007/10/03)
-
- Palladium-catalyzed benzylic C-H borylation of alkylbenzenes with bis(pinacolato)diboron or pinacolborane
-
Borylation at the benzylic C-H bond of alkylbenzenes with bis(pinacolato)diboron [(Me4C2O2)B-B(O2C2Me 4)] or pinacolborane [(Me4C2O2)B-H] was carried out at
- Ishiyama, Tatsuo,Ishida, Kousaku,Takagi, Jun,Miyaura, Norio
-
p. 1082 - 1083
(2007/10/03)
-
- A preparation of benzylic and allylic boronates: Cross-coupling of aryl- and alkenylstannanes with bromomethylboronates
-
Palladium catalyzed cross-coupling of aryl- or alkenylstannanes with pinacol and pinanediol bromomethylboronates affords the corresponding homologated benzylic or allylic boronates in moderate to good yields.
- Falck,Bondlela, Muralidhar,Ye, Jianhua,Su-Dong, Cho
-
p. 5647 - 5650
(2007/10/03)
-