- A long-wavelength fluorescent probe for saccharides based on boronic-acid receptor
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A single boronic acid-based fluorescent probe (compound CSP) for saccharides was designed and synthesized. The probe, with an α,-unsaturated ketone conjugated into the coumarin fluorophore, was synthesized by 4 steps from the commercial material 4-diethylamino salicylaldehyde. The electron push-pull effect is enhanced with the N,N-diethyl amino as the electron donor and the carbonyl as the electron acceptor. Both the absorption (463 nm) and emission (616 nm) maxima of CSP are in the visible wavelength region with a Stokes shift of about 150 nm, which ensures CSP a potential probe for biological application. Under near physiological conditions, significant fluorescence enhancement of CSP was observed upon the addition of some saccharides, namely, D-sorbitol, D-fructose, D-glucose, D-mannose and D-galactose. The probe showed relatively high sensitivity towards D-fructose and D-sorbitol, and their detection limits were 0.05 mmol/L and 0.1 mmol/L, respectively. A fluorescent sensor CSP for saccharides was designed and synthesized based on electron transfer mechanism. The conjugation was extended by incorporating an α,β-unsaturated ketone into the coumarin fluorophore. The sensor has good water-solubility, large Stocks shift (≈150 nm) and long emission wavelength (616 nm), which ensure CSP a potential sensor for sugars in biological systems. Copyright
- Bai, Hongyan,Sun, Qian,Tian, Haiyu,Qian, Junhong,Zhang, Lingyi,Zhang, Weibing
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Read Online
- 18-Crown-6 Catalyzed Microwave-mediated Synthesis of Symmetric Bis-Heterocyclic Compounds under Solvent-free Condition
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An efficient, solvent-free and 18-crown-6 catalyzed method for the synthesis of N-alkyl-4-(4-(5-(2-(alkyl-amino)thiazol-4-yl)pyridin-3-yl)phenyl)thiazol-2-amine, N-alkyl-4-(5-(2-alkyamino)thiazol-4-yl)pyridine-3-yl)thiazol-2-amine, and 4,4′-bis-{2-[amino]-4-thiazolyl}biphenyl bis-heterocyclic derivatives via microwave accelerated cyclization is presented.
- Rishikesan, Rathnasamy,Prabakaran, Kamalakannan,Murugesan, Rajamani,Venkataraman, Ramaswamy,Ranjith, Pakkath Karuvalam,Arvind, Sivasubramanian,Thennarasu, Sathiah
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Read Online
- Palladium-catalyzed borylation of aryl bromides and chlorides using phosphatrioxa-adamantane ligands
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Catalysts based on the combination of Pd(OAc)2 and the electron-deficient phosphatrioxa-adamantane ligands are described for borylation of aryl bromides and chlorides. Catalytic evaluation of a small library of phosphatrioxa-adamantane ligands provided some insights on the preferred ligand steric profile for borylation reactions. The corresponding aryl boronate esters were accessed under mild conditions (25–70 °C) and isolated in high yields (up to 96%).
- Lamola, Jairus L.,Moshapo, Paseka T.,Holzapfel, Cedric W.,Christopher Maumela, Munaka
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supporting information
(2021/12/13)
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- Unreactive C-N Bond Activation of Anilines via Photoinduced Aerobic Borylation
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Unreactive C-N bond activation of anilines was achieved by photoinduced aerobic borylation. A diverse range of tertiary and secondary anilines were converted to aryl boronate esters in moderate to good yields with wide functional group tolerance under simple and ambient photochemical conditions. This transformation achieved the direct and facile C-N bond activation of unreactive anilines, providing a convenient and practical route transforming widely available anilines into useful aryl boronate esters.
- Ji, Shuohan,Qin, Shengxiang,Yin, Chunyu,Luo, Lu,Zhang, Hua
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supporting information
p. 64 - 68
(2021/12/27)
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- HCl-Catalyzed Aerobic Oxidation of Alkylarenes to Carbonyls
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The construction of C?O bonds through C?H bond functionalization remains fundamentally challenging. Here, a practical chlorine radical-mediated aerobic oxidation of alkylarenes to carbonyls was developed. This protocol employed commercially available HCl as a hydrogen atom transfer (HAT) reagent and air as a sustainable oxidant. In addition, this process exhibited excellent functional group tolerance and a broad substrate scope without the requirement for external metal and oxidants. The mechanistic hypothesis was supported by radical trapping, 18O labeling, and control experiments.
- Niu, Kaikai,Shi, Xiaodi,Ding, Ling,Liu, Yuxiu,Song, Hongjian,Wang, Qingmin
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- Polysulfide Anions as Visible Light Photoredox Catalysts for Aryl Cross-Couplings
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Polysulfide anions are endowed with unique redox properties, attracting considerable attentions for their applications in alkali metals-sulfur batteries. However, the employment of these anionic species in redox catalysis for small molecule synthesis remains underdeveloped due to their moderate-poor electrochemical potential in the ground state, whereas some of them are characterized by photoabsorptions in visible spectral regions. Herein, we disclose the use of polysulfide anions as visible light photoredox catalysts for aryl cross-coupling reactions. The reaction design enables single-electron reduction of aryl halides upon the photoexcitation of tetrasulfide dianions (S42-). The resulting aryl radicals are engaged in (hetero)biaryl cross-coupling, borylation, and hydrogenation in a redox catalytic regime involving S4?-/S42- and S3?-/S32- redox couples.
- Li, Haoyu,Tang, Xinxin,Pang, Jia Hao,Wu, Xiangyang,Yeow, Edwin K. L.,Wu, Jie,Chiba, Shunsuke
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supporting information
p. 481 - 487
(2021/01/13)
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- One-pot synthesis of Ag-Cu-Cu2O/C nanocomposites derived from a metal-organic framework as a photocatalyst for borylation of aryl halide
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Mixed metal-metal oxide/C (Ag-Cu-Cu2O/C) nanocomposites were synthesized by the heat treatment of a metal-organic framework under a N2 flow using the one-pot synthesis method. The as-prepared nanocomposites were characterized using a range of techniques,
- Annas, Dicky,Bae, Jong-Seong,Hira, Shamim Ahmed,Park, Kang Hyun,Park, Sungkyun,Song, Sehwan
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p. 32965 - 32972
(2021/12/07)
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- Recyclable Pd2dba3/XPhos/PEG-2000 System for Efficient Borylation of Aryl Chlorides: Practical Access to Aryl Boronates
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Pd2dba3/XPhos in poly(ethylene glycol) (PEG-2000) is shown to be a highly stable and efficient catalyst for the borylation of aryl chlorides with bis(pinacolato)diboron. The borylation reaction proceeds smoothly at 110 °C, delivering a wide variety of aryl boronates in good to excellent yields with high functional group tolerance. The crude products were easily isolated via simple extraction of the reaction mixture with cyclohexane. Moreover, both expensive Pd2dba3 and XPhos in PEG-2000 system could be readily recycled and reused more than six times without loss of catalytic efficiency.
- Cai, Mingzhong,Huang, Bin,Luo, Chengkai,Xu, Caifeng
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- Synthesis of arylboronates via the Pd-catalyzed desulfitative coupling reaction of sodium arylsulfinates with bis(pinacolato)diboron
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The desulfitative borylation reaction of sodium arylsulfinates with bis(pinacolato)diboron or bis(neopentylglycolato)diboron under palladium catalysis has been developed, allowing selective C-B bond formation to give arylboronates with a range of functional groups in moderate to good yields under mild reaction conditions. A gram-scale preparation as well as the cascade Suzuki-Miyaura cross-coupling of arylboronates demonstrated the potential practical utility in organic synthesis.
- Qiu, Di,Li, Songyi,Yue, Guanglu,Mao, Jinshan,Xu, Bei,Yuan, Xinyu,Ye, Fei
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- Light-DrivenN-Heterocyclic Carbene Catalysis Using Alkylborates
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Radical-radical coupling, the selective reaction between two different radical species, has contributed to the methodology for connecting bulky units. Light-drivenN-heterocyclic carbene (NHC) organocatalysis is recognized as a state-of-the-art methodology enabling radical-radical coupling. The catalytic process involves forming an acyl azolium intermediate from the NHC catalyst and an acyl donor, followed by single electron reduction of this key intermediate, which is largely dependent on the photoredox catalyst. We designed a radical NHC catalysis in which the direct photoexcitation of a borate to form a high reducing agent facilitated the single electron reduction event. The borate produces an alkyl radical for the single electron transfer process to accomplish the radical-radical coupling. This protocol enables cross-coupling between alkylborates and acyl imidazoles in addition to radical relay-type alkylacylations of alkenes with alkylborates and acyl imidazoles, affording ketones with a broad scope.
- Sato, Yukiya,Goto, Yamato,Nakamura, Kei,Miyamoto, Yusuke,Sumida, Yuto,Ohmiya, Hirohisa
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p. 12886 - 12892
(2021/10/29)
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- Oxidative Cleavage of Alkenes by O2with a Non-Heme Manganese Catalyst
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The oxidative cleavage of C═C double bonds with molecular oxygen to produce carbonyl compounds is an important transformation in chemical and pharmaceutical synthesis. In nature, enzymes containing the first-row transition metals, particularly heme and non-heme iron-dependent enzymes, readily activate O2 and oxidatively cleave C═C bonds with exquisite precision under ambient conditions. The reaction remains challenging for synthetic chemists, however. There are only a small number of known synthetic metal catalysts that allow for the oxidative cleavage of alkenes at an atmospheric pressure of O2, with very few known to catalyze the cleavage of nonactivated alkenes. In this work, we describe a light-driven, Mn-catalyzed protocol for the selective oxidation of alkenes to carbonyls under 1 atm of O2. For the first time, aromatic as well as various nonactivated aliphatic alkenes could be oxidized to afford ketones and aldehydes under clean, mild conditions with a first row, biorelevant metal catalyst. Moreover, the protocol shows a very good functional group tolerance. Mechanistic investigation suggests that Mn-oxo species, including an asymmetric, mixed-valent bis(μ-oxo)-Mn(III,IV) complex, are involved in the oxidation, and the solvent methanol participates in O2 activation that leads to the formation of the oxo species.
- Bennett, Elliot L.,Brookfield, Adam,Guan, Renpeng,Huang, Zhiliang,Mcinnes, Eric J. L.,Robertson, Craig M.,Shanmugam, Muralidharan,Xiao, Jianliang
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supporting information
p. 10005 - 10013
(2021/07/19)
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- Method for catalytically synthesizing phenylboronic acid ester derivative by iridium catalyst
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The invention relates to a method for catalytically synthesizing a phenylboronic acid ester derivative by using an iridium catalyst. The method comprises the following steps: by using a cyclooctadieneiridium chloride dimer as a catalyst, dissolving aryl halide and pinacol borane in an organic solvent to react, and carrying out aftertreatment to obtain the phenylboronic acid ester derivative. Compared with the prior art, the method has the advantages that the method is simple and green, cheap, readily available and stable raw materials of aryl halide and pinacol borane are used, the reaction conditions are mild, corresponding products can be obtained at high yield through reaction at room temperature in a non-inert atmosphere, and the method has good substrate universality, so that the method is better convenient to apply.
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Paragraph 0042-0045
(2021/01/11)
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- Electrochemical Thiolation and Borylation of Arylazo Sulfones with Thiols and B2pin2
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An efficient electrochemical synthesis approach of various unsymmetrical thioethers and arylboronates has been developed. Bench stable arylazo sulfones were used as radical precursors for carbon-heteroatom bond formation under electrochemical conditions. Moreover, the scalability of this approach was evaluated by performing the electrochemical thiolation and borylation of arylazo sulfones with thiols and B2pin2 on a gram scale. This protocol not only avoided the use of stoichiometric oxidants, metal catalysts, activating agents and even added bases, but also exhibited favorable functional group tolerance. (Figure presented.).
- Wang, Rongkang,Chen, Fangming,Jiang, Lvqi,Yi, Wenbin
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supporting information
p. 1904 - 1911
(2021/02/12)
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- Facile and economical Miyaura borylation and one-pot Suzuki–Miyaura cross-coupling reaction
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Facile and economical method for Miyaura borylation reaction between B2pin2 and aryl bromides is reported. The catalytic system containing 2 mol% PdCl2(PPh3)2 and KOAc serves to enable borylations to occur under solvent-free and atmospheric conditions. The developed protocol can be applied to synthesize symmetrical and unsymmetrical biaryls via one-pot two-step Suzuki–Miyaura cross-coupling reaction and also offers the up-scalability.
- Boontiem, Phongsakorn,Kiatisevi, Supavadee
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- Reductive Electrophotocatalysis: Merging Electricity and Light to Achieve Extreme Reduction Potentials
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We describe a new electrophotocatalytic strategy that harnesses the power of light and electricity to generate an excited radical anion with a reducing potential of -3.2 V vs SCE, which can be used to activate substrates with very high reduction potentials (Ered ≈ -1.9 to -2.9 V). The resultant aryl radicals can be engaged in various synthetically useful transformations to furnish arylboronate, arylstannane, and biaryl products.
- Kim, Hyunwoo,Kim, Hyungjun,Lambert, Tristan H.,Lin, Song
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supporting information
p. 2087 - 2092
(2020/02/04)
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- Luminescent tungsten(vi) complexes as photocatalysts for light-driven C-C and C-B bond formation reactions
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The realization of photocatalysis for practical synthetic application hinges on the development of inexpensive photocatalysts which can be prepared on a large scale. Herein an air-stable, visible-light-absorbing photoluminescent tungsten(vi) complex which can be conveniently prepared at the gram-scale is described. This complex could catalyse photochemical organic transformation reactions including borylation of aryl halides, such as aryl chloride, reductive coupling of benzyl bromides for C-C bond formation, reductive coupling of phenacyl bromides, and decarboxylative coupling of redox-active esters of alkyl carboxylic acid with high product yields and broad functional group tolerance.
- Chan, Kaai-Tung,Che, Chi-Ming,Du, Lili,Liu, Yungen,Phillips, David Lee,To, Wai-Pong,Tong, Glenna So Ming,Wu, Liang-Liang,Yu, Daohong
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p. 6370 - 6382
(2020/07/15)
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- Photocatalytic C–X borylation of aryl halides by hierarchical SiC nanowire-supported Pd nanoparticles
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Hierarchical SiC nanowire-supported Pd nanoparticles showed high photocatalytic activity for the C-X (X = Br, I) borylation of aryl halides at 30 °C. The SiC/Pd Mott-Schottky contact enhances the rapid transfer of the photogenerated electrons from SiC to the Pd nanoparticles. As a result, the concentrated energetic electrons in the Pd nanoparticles can facilitate the cleavage of C-I or C-Br bonds, which normally requires high-temperature thermal processes. We show that the present Pd/SiC photocatalyst is capable of catalyzing the transformation of a large variety of aryl halides to their corresponding boronate esters under visible light irradiation, with excellent yields.
- Jiao, Zhi-Feng,Zhao, Ji-Xiao,Guo, Xiao-Ning,Guo, Xiang-Yun
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p. 357 - 363
(2019/12/28)
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- Chemoselective Rhodium-Catalyzed Borylation of Bromoiodoarenes under Mild Conditions
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A chemoselective rhodium-catalyzed borylation has been developed for the preparation of aryl boronate esters. The reaction proceeds under mild conditions with excellent selectivity for C-I bonds in bromoiodoarenes and exhibits broad functional group tolerance. This procedure can act as a complementary approach toward bifunctional arenes along with other metal-catalyzed borylations. Additionally, the reaction's utility in the preparation of monomers for metal-catalyzed cross-coupling polymerization is demonstrated.
- Varni, Anthony J.,Bautista, Michael V.,Noonan, Kevin J.T.
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p. 6770 - 6777
(2020/07/21)
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- Rhodium-Catalyzed Deoxygenation and Borylation of Ketones: A Combined Experimental and Theoretical Investigation
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The rhodium-catalyzed deoxygenation and borylation of ketones with B2pin2 have been developed, leading to efficient formation of alkenes, vinylboronates, and vinyldiboronates. These reactions feature mild reaction conditions, a broad substrate scope, and excellent functional-group compatibility. Mechanistic studies support that the ketones initially undergo a Rh-catalyzed deoxygenation to give alkenes via boron enolate intermediates, and the subsequent Rh-catalyzed dehydrogenative borylation of alkenes leads to the formation of vinylboronates and diboration products, which is also supported by density functional theory calculations.
- Tao, Lei,Guo, Xueying,Li, Jie,Li, Ruoling,Lin, Zhenyang,Zhao, Wanxiang
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supporting information
p. 18118 - 18127
(2020/11/26)
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- Rh-Catalyzed Base-Free Decarbonylative Borylation of Twisted Amides
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We report the rhodium-catalyzed base-free decarbonylative borylation of twisted amides. The synthesis of versatile arylboronate esters from aryl twisted amides is achieved via decarbonylative rhodium(I) catalysis and highly selective N-C(O) insertion. The method is notable for a very practical, additive-free Rh(I) catalyst system. The method shows broad functional group tolerance and excellent substrate scope, including site-selective decarbonylative borylation/Heck cross-coupling via divergent N-C/C-Br cleavage and late-stage pharmaceutical borylation.
- Bie, Fusheng,Liu, Xuejing,Shi, Yijun,Cao, Han,Han, Ying,Szostak, Michal,Liu, Chengwei,Liu, Xuejing,Szostak, Michal,Liu, Chengwei
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p. 15676 - 15685
(2020/11/13)
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- Visible-Light-Induced Ni-Catalyzed Radical Borylation of Chloroarenes
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A highly selective and general photoinduced C-Cl borylation protocol that employs [Ni(IMes)2] (IMes = 1,3-dimesitylimidazoline-2-ylidene) for the radical borylation of chloroarenes is reported. This photoinduced system operates with visible light (400 nm) and achieves borylation of a wide range of chloroarenes with B2pin2 at room temperature in excellent yields and with high selectivity, thereby demonstrating its broad utility and functional group tolerance. Mechanistic investigations suggest that the borylation reactions proceed via a radical process. EPR studies demonstrate that [Ni(IMes)2] undergoes very fast chlorine atom abstraction from aryl chlorides to give [NiI(IMes)2Cl] and aryl radicals. Control experiments indicate that light promotes the reaction of [NiI(IMes)2Cl] with aryl chlorides generating additional aryl radicals and [NiII(IMes)2Cl2]. The aryl radicals react with an anionic sp2-sp3 diborane [B2pin2(OMe)]- formed from B2pin2 and KOMe to yield the corresponding borylation product and the [Bpin(OMe)]?- radical anion, which reduces [NiII(IMes)2Cl2] under irradiation to regenerate [NiI(IMes)2Cl] and [Ni(IMes)2] for the next catalytic cycle.
- Tian, Ya-Ming,Guo, Xiao-Ning,Krummenacher, Ivo,Wu, Zhu,Nitsch, J?rn,Braunschweig, Holger,Radius, Udo,Marder, Todd B.
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supporting information
p. 18231 - 18242
(2020/11/02)
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- Controllable factors of supported IR complex catalysis for aromatic C?H borylation
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We have developed a catalyst in which an Ir complex and organic functionalities are coimmobilized on the silica surface. The catalytic activity for aromatic C?H borylation was significantly affected by (i) the linker length of the Ir?bipyridine complex, (ii) the coimmobilized organic functionality, and (iii) the substituents on the aromatic substrate compounds. The fine-tuned supported catalyst showed higher activity than the homogeneous Ir?bipyridine complex when using a specific substrate such as benzonitrile. We elucidated this property by conducting solid-state NMR, FT-IR, XAFS, and in situ FT-IR analysis.
- Chun, Wang-Jae,Maeda, Kyogo,Manaka, Yuichi,Motokura, Ken,Nakajima, Kiyotaka,Satter, Shazia Sharmin,Uemura, Yohei
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p. 14552 - 14559
(2020/12/21)
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- Room temperature Pd(0)/Ad3P-catalyzed coupling reactions of aryl chlorides with bis(pinacolato)diboron
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Room temperature Pd(0)/Ad3P-catalyzed cross-coupling reactions of aryl chlorides with bis(pinacolato)diboron are described. The Pd(0)/Ad3P catalyst, generated from Ad3P-coordinated acetanilide-based palladacycle complex, proved to be an efficient catalyst system for the Miyaura borylation reactions of a variety of aryl chlorides with bis(pinacolato)diboron. The mild reaction condition, the easy availability of the catalyst and good coupling yields make these reactions potentially useful in organic synthesis.
- Dong, Jie,Guo, Hui,Peng, Wei,Hu, Qiao-Sheng
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p. 760 - 763
(2019/02/16)
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- Organophotocatalytic Arene Functionalization: C-C and C-B Bond Formation
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Organophotocatalytic C-C and C-B bond formation reactions of aryl halides have been developed in the presence of an organophotosensitizer, 3,7-di([1,1′-biphenyl]-4-yl)-10-(4-(trifluoromethyl)phenyl)-10H-phenoxazine that has highly negative reduction potential at its photoexcited state. The developed reaction conditions are mild and allow the intermolecular C-C bond formation of the generated aryl radical with electron-rich (hetero)arenes and C-B bond formation with bis(pinacolato)diboron.
- Lee, Da Seul,Kim, Chung Soo,Iqbal, Naila,Park, Gyeong Su,Son, Kyung-Sun,Cho, Eun Jin
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supporting information
p. 9950 - 9953
(2019/12/24)
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- Copper-Photocatalyzed Borylation of Organic Halides under Batch and Continuous-Flow Conditions
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The copper-photocatalyzed borylation of aryl, heteroaryl, vinyl and alkyl halides (I and Br) was reported. The reaction proceeded using a new heteroleptic Cu complex under irradiation with blue LEDs, giving the corresponding boronic-acid esters in good to excellent yields. The reaction was extended to continuous-flow conditions to allow an easy scale-up. The mechanism of the reaction was studied and a mechanism based on a reductive quenching (CuI/CuI*/Cu0) was suggested.
- Nitelet, Antoine,Thevenet, Damien,Schiavi, Bruno,Hardouin, Christophe,Fournier, Jean,Tamion, Rodolphe,Pannecoucke, Xavier,Jubault, Philippe,Poisson, Thomas
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supporting information
p. 3262 - 3266
(2019/02/13)
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- Meta-Selective C-H Borylation of Benzamides and Pyridines by an Iridium-Lewis Acid Bifunctional Catalyst
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We report herein the iridium-catalyzed meta-selective C-H borylation of benzamides by using a newly designed 2,2′-bipyridine (bpy) ligand bearing an alkylaluminum biphenoxide moiety. We also demonstrate the iridium-catalyzed C3-selective C-H borylation of pyridine with a 1,10-phenanthroline (Phen) ligand bearing an alkylborane moiety. It is proposed that the Lewis acid-base interaction between the Lewis acid moiety and the aminocarbonyl group or the sp2-hybridized nitrogen atom accelerates the reaction and controls the site-selectivity.
- Yang, Lichen,Uemura, Nao,Nakao, Yoshiaki
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supporting information
p. 7972 - 7979
(2019/05/22)
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- Visible light-promoted formation of C-B and C-S bonds under metal- A nd photocatalyst-free conditions
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A green, efficient, photoinduced synthesis of arylboronic esters and aryl sulfides has been developed. Bench stable arylazo sulfones were used as radical precursors for a photocatalyst- A nd additive-free carbon-heteroatom bond formation under visible light. The protocols are applicable to a wide range of substrates, providing products in good yields.
- Blank, Lena,Fagnoni, Maurizio,Protti, Stefano,Rueping, Magnus
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p. 1243 - 1252
(2019/02/26)
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- Method for preparing aryl boronate at room temperature
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The invention discloses a method for preparing aryl boronate represented by a formula I at a room temperature. The method comprises: carrying out a reaction on a diboron compound represented by a formula II and an aryl halide in an organic solvent for 0.5-8 h at a room temperature under the actions of an alkali, a chloro(2-dicyclohexylphosphino-2',4',6'-tri-isopropyl-1,1'-biphenyl)(2'-amino-1,1'-biphenyl-2-yl)palladium (II) catalyst and a 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl ligand, and carrying out post-treatment to obtain the corresponding aryl boronate. According to the present invention, the method has characteristics of mild reaction conditions, simple operation, wide application range, good compatibility with various functional groups on aryl, high efficiency and economy, can achieve high yield of aryl borate under normal pressure and normal pressure conditions, and is suitable for large-scale preparation of aryl borate. The formulas I and II are defined in the specification, wherein R' represents any one selected from phenyl with substituent, pyridyl, thienyl, indyl, pyrazolyl and naphthyl.
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Paragraph 0020-0022; 0036-0038
(2019/05/11)
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- Balancing Bulkiness in Gold(I) Phosphino-triazole Catalysis
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The syntheses of a series of 1-phenyl-5-phosphino 1,2,3-triazoles are disclosed, within which, the phosphorus atom (at the 5-position of a triazole) is appended by one, two or three triazole motifs, and the valency of the phosphorus(III) atom is completed by two, one or zero ancillary (phenyl or cyclohexyl) groups respectively. This series of phosphines was compared with tricyclohexylphosphine and triphenylphosphine to study the effect of increasing the number of triazoles appended to the central phosphorus atom from zero to three triazoles. Gold(I) chloride complexes of the synthesised ligands were prepared and analysed by techniques including single-crystal X-ray diffraction structure determination. Gold(I) complexes were also prepared from 1-(2,6-dimethoxy)-phenyl-5-dicyclohexyl-phosphino 1,2,3-triazole and 1-(2,6-dimethoxy)-phenyl-5-diphenyl-phosphino 1,2,3-triazole ligands. The crystal structures thus obtained were examined using the SambVca (2.0) web tool and percentage buried volumes determined. The effectiveness of these gold(I) chloride complexes to serve as precatalysts for alkyne hydration were assessed. Furthermore, the regioselectivity of hydration of but-1-yne-1,4-diyldibenzene was probed.
- Zhao, Yiming,Wakeling, Matthew G.,Meloni, Fernanda,Sum, Tze Jing,van Nguyen, Huy,Buckley, Benjamin R.,Davies, Paul W.,Fossey, John S.
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p. 5540 - 5548
(2019/08/07)
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- Room-temperature borylation and one-pot two-step borylation/Suzuki-Miyaura cross-coupling reaction of aryl chlorides
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A highly efficient room-temperature borylation strategy of aryl chlorides is described. Utilizing Buchwald's second-generation preformed catalyst, boronate esters were obtained for a wide range of substrates in high yield. The method was also applied to Suzuki-Miyaura cross-coupling reaction in a one-pot two-step sequential manner, providing a facile and convenient access to the direct synthesis of biaryl compounds from aryl chlorides.
- Ji, Hong,Wu, Li-Yang,Cai, Jiang-Hong,Li, Guo-Rong,Gan, Na-Na,Wang, Zhao-Hua
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p. 13643 - 13648
(2018/04/24)
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- Bedford-type palladacycle-catalyzed miyaura borylation of aryl halides with tetrahydroxydiboron in water
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A mild aqueous protocol for palladium catalyzed Miyaura borylation of aryl iodides, aryl bromides and aryl chlorides with tetrahydroxydiboron (BBA) as a borylating agent is developed. The developed methodology requires low catalyst loading of Bedford-type palladacycle catalyst (0.05 mol %) and works best under mild reaction conditions at 40 °C in short time of 6 h in water. In addition, our studies show that for Miyaura borylation using BBA in aqueous condition, maintaining a neutral reaction pH is very important for reproducibility and higher yields of corresponding borylated products. Moreover, our protocol is applicable for a broad range of aryl halides, corresponding borylated products are obtained in excellent yields up to 93% with 29 examples demonstrating its broad utility and functional group tolerance.
- Zernickel, Anna,Du, Weiyuan,Ghorpade, Seema A.,Sawant, Dinesh N.,Makki, Arwa A.,Sekar, Nagaiyan,Eppinger, J?rg
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p. 1842 - 1851
(2018/02/23)
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- Controllable Rh(III)-Catalyzed C-H Arylation and Dealcoholization: Access to Biphenyl-2-carbonitriles and Biphenyl-2-carbimidates
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A controllable Rh(III)-catalyzed C-H arylation and dealcoholization of benzimidates with arylboronic esters was developed, delivering various biphenyl-2-carbonitriles and biphenyl-2-carbimidates by simply tuning the reaction conditions. This approach features high efficiency, good functional group tolerance, and easy operation. It also provides an alternative pathway to thoroughly exploit the directing group in transition-metal-catalyzed C-H activations.
- Jiang, Bo,Wu, Songxiao,Zeng, Jing,Yang, Xiaobo
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supporting information
p. 6573 - 6577
(2018/10/09)
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- Employing Water as the Hydride Source in Synthesis: A Case Study of Diboron Mediated Alkyne Hydroarylation
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We present an approach to utilize water as the hydride source via Pd(II)/Pd(0) catalysis. As a case study, we have achieved a diboron mediated Pd(II)-catalyzed hydroarylation of alkynes using arylboronic acids. This approach not only complements conventional reactivity of Pd via Pd(0)/Pd(II) cycle for the hydroarylation but also utilizes water as the hydride source. We believe this would particularly be beneficial in utilizing water as a reagent.
- Rao, Santhosh,Joy, M. Nibin,Prabhu, Kandikere Ramaiah
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supporting information
p. 13707 - 13715
(2018/11/30)
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- Additive- and Photocatalyst-Free Borylation of Arylazo Sulfones under Visible Light
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We developed a photocatalyst-free and additive-free, visible light induced borylation reaction using arylazo sulfones as starting material. This protocol shows some advantages such as mild conditions, simple equipment, and wide substrate scope, which gives a complementary protocol for the preparation of arylboronates.
- Xu, Yuliang,Yang, Xinying,Fang, Hao
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p. 12831 - 12837
(2018/10/20)
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- Palladium-Catalyzed Decarbonylative Borylation of Carboxylic Acids: Tuning Reaction Selectivity by Computation
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Decarbonylative borylation of carboxylic acids is reported. Carbon electrophiles are generated directly after reagent-enabled decarbonylation of the in situ accessible sterically-hindered acyl derivative of a carboxylic acid under catalyst controlled conditions. The scope and the potential impact of this method are demonstrated in the selective borylation of a variety of aromatics (>50 examples). This strategy was used in the late-stage derivatization of pharmaceuticals and natural products. Computations reveal the mechanistic details of the unprecedented C?O bond activation of carboxylic acids. By circumventing the challenging decarboxylation, this strategy provides a general synthetic platform to access arylpalladium species for a wide array of bond formations from abundant carboxylic acids. The study shows a powerful combination of experiment and computation to predict decarbonylation selectivity.
- Liu, Chengwei,Ji, Chong-Lei,Hong, Xin,Szostak, Michal
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supporting information
p. 16721 - 16726
(2018/11/30)
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- LiHMDS-Promoted Palladium or Iron-Catalyzed ipso-Defluoroborylation of Aryl Fluorides
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A novel and efficient method for the synthesis of arylboronic acid pinacol esters via a palladium- or iron-catalyzed cross-coupling reaction of aryl fluorides with bis(pinacolato)diboron (B2pin2) in the presence of LiHMDS was developed. The Pd-catalyzed defluoroborylation of fluoroarenes is compatible with a variety of functional groups such as primary and secondary amine, ketone, trifluoromethyl, alkoxy, and boryl. Remarkably, no external ligand is required for enhanced conversion efficiency.
- Zhao, Xianghu,Wu, Mingsheng,Liu, Yisen,Cao, Song
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supporting information
p. 5564 - 5568
(2018/09/12)
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- Borylation of aryldiazonium salts at room temperature in an aqueous solution under catalyst-free conditions
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A general and convenient borylation reaction of aryldiazonium tetrafluoroborate salts with B2pin2 has been developed. In this catalytic system, no catalyst, additional ligands or additives were required. The reaction proceeded smoothly in an aqueous solution, and a variety of arylboronates were isolated in moderate to excellent yields under mild reaction conditions.
- Qi, Xinxin,Li, Hao-Peng,Peng, Jin-Bao,Wu, Xiao-Feng
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supporting information
p. 3851 - 3853
(2017/09/15)
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- Radical Metal-Free Borylation of Aryl Iodides
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A simple metal-free borylation of aryl iodides mediated by a fluoride sp 2 -sp 3 diboron adduct is described. The reaction conditions are compatible with various functional groups. Electronic effects of substituents do not affect the borylation while steric hindrance does. The reaction proceeds via a radical mechanism in which pyridine serves to stabilize the boryl radicals, generated in situ.
- Pinet, Sandra,Liautard, Virginie,Debiais, Mégane,Pucheault, Mathieu
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p. 4759 - 4768
(2017/10/03)
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- Convenient and General Zinc-Catalyzed Borylation of Aryl Diazonium Salts and Aryltriazenes under Mild Conditions
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A convenient and general zinc-catalyzed borylation of aryl diazonium salts and aryltriazenes has been developed. With bis- (pinacolato)diboron as the borylation reagent, aryldiazonium tetrafluoroborate salts and aryltriazenes were transformed into the corresponding arylboronates in moderate to excellent yields under mild conditions. As a convenient and practical methodology, no additional ligands, base, or any other additives are required here.
- Qi, Xinxin,Jiang, Li-Bing,Zhou, Chao,Peng, Jin-Bao,Wu, Xiao-Feng
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p. 345 - 349
(2017/06/23)
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- Room Temperature Ni0/PCy3-Catalyzed Coupling Reactions of Aryl Arenesulfonates with Bis(pinacolato)diboron
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Room temperature Ni0/PCy3-catalyzed cross-coupling reactions of aryl arenesulfonates with bis(pinacolato)diboron are described. The Ni0/PCy3 catalysts, generated from Ni(COD)2 and PCy3, or air-stable 4-MeOC6H4NiII(PCy3)2OTs, were efficient catalyst systems for the Miyaura borylation reactions of a variety of aryl arenesulfonates with bis(pinacolato)diboron. The mild reaction condition, the easy availability of the catalysts and good yields make these reactions potentially useful in organic synthesis (Cy = cyclohexyl, COD = cyclooctadiene, OTs = tosyl).
- Dong, Jie,Guo, Hui,Hu, Qiao-Sheng
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supporting information
p. 7087 - 7090
(2017/12/28)
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- Miyaura Borylation and One-Pot Two-Step Homocoupling of Aryl Chlorides and Bromides under Solvent-Free Conditions
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Solvent-free protocols for Miyaura borylation and the one-pot, two-step homocoupling of aryl halides are reported for the first time. Bis(dibenzylideneacetone)palladium(0) [Pd(dba)2] is an optimal source of palladium for Miyaura borylation, while for one-pot two-step homocoupling palladium(II) acetate [Pd(OAc)2] gives highest yields. Aryl bromides are coupled most efficiently using the DPEphos ligand. Chlorides are coupled using XPhos. The developed protocols are robust, versatile and easily reproducible on a large scale.
- Dzhevakov, Pavel B.,Topchiy, Maxim A.,Zharkova, Daria A.,Morozov, Oleg S.,Asachenko, Andrey F.,Nechaev, Mikhail S.
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p. 977 - 983
(2016/04/05)
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- Visible-Light Photoredox Borylation of Aryl Halides and Subsequent Aerobic Oxidative Hydroxylation
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Efficient and practical visible-light photoredox borylation of aryl halides and subsequent aerobic oxidative hydroxylation were developed. The protocols use readily available aryl halides and bis(pinacolato)diboron as the starting materials, fac-Ir(ppy)3 as the photocatalyst, and corresponding arylboronic esters and phenols were obtained in good yields. The methods show some advantages including simple equipment, mild conditions, easy operation, and wide substrate scope. Therefore, they should provide a valuable strategy for chemical transformations.
- Jiang, Min,Yang, Haijun,Fu, Hua
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supporting information
p. 5248 - 5251
(2016/11/02)
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- 2-Aryl-indenylphosphine ligands: Design, synthesis and application in Pd-catalyzed Suzuki-Miyaura coupling reactions
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A focused library of phosphine ligands was constructed for structural optimization. The catalyst can be used to perform the Suzuki-Miyaura cross-coupling reaction of aryl and heteroaryl chlorides.
- Lian, Ze-Yu,Yuan, Jia,Yan, Meng-Qi,Liu, Yan,Luo, Xue,Wu, Qing-Guo,Liu, Sheng-Hua,Chen, Jian,Zhu, Xiao-Lei,Yu, Guang-Ao
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supporting information
p. 10090 - 10094
(2016/11/06)
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- Efficient metal-free photochemical borylation of aryl halides under batch and continuous-flow conditions
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A rapid, chemoselective and metal-free C-B bond-forming reaction of aryl iodides and bromides in aqueous solution at low temperatures was discovered. This reaction is amenable to batch and continuous-flow conditions and shows exceptional functional group tolerance and broad substrate scope regarding both the aryl halide and the borylating reagent. Initial mechanistic experiments indicated a photolytically generated aryl radical as the key intermediate.
- Chen, Kai,Zhang, Shuai,He, Pei,Li, Pengfei
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p. 3676 - 3680
(2016/06/09)
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- Phosphine and palladium-free synthesis of aryl and alkenyl boronates: A nano-catalytic approach
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Superparamagnetic copperferrite nanoparticle is employed as an environmentally benign and efficient catalyst to affect the borylation of aryliodides yielding the corresponding arylboronates at low catalyst loading under mild reaction conditions. This protocol tolerates various substituents present in aryl iodides and also could be extended to beta bromostyrenes in the absence of phosphine and palladium.
- Mohan, Balaji,Kang, Hyuntae,Park, Kang Hyun
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- SPIRO COMPOUNDS AS HEPATITIS C VIRUS INHIBITORS
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Disclosed are spiro compounds of formula (I), or stereomers, geometric isomers, tautomers, nitrogen oxides, hydrates, solvates, metabolites, pharmaceutically acceptable salts or prodrugs thereof. The compounds can be used to treat hepatitis C virus (HCV) infection or hepatitis C disease. Furthermore disclosed are pharmaceutical compositions containing the compounds and the method of using the compounds or pharmaceutical compositions in the treatment of HCV infection or hepatitis C disease.
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Paragraph 0408
(2015/11/09)
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- Efficient phosphine ligands for the one-pot palladium-catalyzed borylation/Suzuki-Miyaura cross-coupling reaction
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We report the synthesis of 2-(anthracen-9-yl)-1H-inden-3-yl dicyclohexylphosphine and its use in palladium-catalyzed borylation/Suzuki-Miyaura cross-coupling reaction to prepare a variety of symmetrical and unsymmetrical biaryl compounds in excellent yield. This journal is
- Chen, You,Peng, Hui,Pi, Yun-Xiao,Meng, Tong,Lian, Ze-Yu,Yan, Meng-Qi,Liu, Yan,Liu, Sheng-Hua,Yu, Guang-Ao
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supporting information
p. 3236 - 3242
(2015/03/18)
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- The method for producing the phenyl boronic acid ester
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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
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Paragraph 0085; 0086
(2018/09/26)
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- Palladium-Catalyzed Monofluoromethylation of Arylboronic Esters with Fluoromethyl Iodide
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The first palladium-catalyzed direct monofluoromethylation of arylboronic esters to produce monofluoromethyl arenes is reported. The reaction is typically carried out at room temperature within 4 h and has a good functional group tolerance. The monofluoromethylating agent, CH2FI, was readily prepared via a halogen-exchange process.
- Hu, Jingyu,Gao, Bing,Li, Lingchun,Ni, Chuanfa,Hu, Jinbo
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supporting information
p. 3086 - 3089
(2015/06/30)
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- FLUORINATION OF ARYL COMPOUNDS
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The invention provides compositions and methods of using the compositions in fluorinating aryl precursors containing a leaving group replaceable by a fluorine atom. The compositions include a metal ion source, a electrophilic fluorine source, a base, and a compound, which is an aryl precursor of the aryl fluoride, and which has a leaving group replaceable by the fluorine atom. Exemplary methods of the invention make use of such compositions and methods to prepare an aryl fluoride compound. In an exemplary embodiment, the electrophilic fluorine source is a source of 18F.
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Paragraph 00123
(2014/07/22)
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- Convenient synthesis of arylboronates through a synergistic Pd/Cu-catalyzed miyaura borylation reaction under atmospheric conditions
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A highly efficient and practical borylation reaction of aryl iodides with bis(pinacolato)diboron has been established. By using Pd(OAc)2, CuI, and PPh3 as a ligand at room temperature under air in the presence of Cs2CO3, the protocol proved to be general. Various functionalized arylboronates were obtained in moderate to excellent yields. In addition, a possible reaction mechanism was proposed. An efficient borylation reaction of aryl iodides with bis(pinacolato)diboron is developed by using Pd(OAc)2 and CuI. This catalytic system has high catalytic efficiency at room temperature in air and functional-group tolerance for a wide range of substrates. Copyright
- Ratniyom, Jadsada,Dechnarong, Nattanee,Yotphan, Sirilata,Kiatisevi, Supavadee
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supporting information
p. 1381 - 1385
(2014/03/21)
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