- Mechanistic insights into the transmetalation step of a Suzuki-Miyaura reaction of 2(4)-bromopyridines: characterization of an intermediate
-
The mechanistic study of the palladium-catalyzed Suzuki-Miyaura cross-coupling between bromophenylpyridine compounds and phenylboronic acid led to the NMR identification of a transient intermediate in the transmetalation step. This species was identified by DFT calculations as a [Pd{Ph-B(OH)3-}{C5H2RN}(PR3)2] complex, containing a boronate ligand coordinated through an oxygen group to the metal center. The fitting of this intermediate within recent mechanistic proposals on the mechanism of transmetalation is discussed.
- Sicre, Cristina,Braga, Ataualpa A.C.,Maseras, Feliu,Cid, M. Magdalena
-
-
Read Online
- Reactivity of 4-methylpyridinium salts in a new reaction of ring transformation of pyridine and isoquinoline derivatives
-
Dependence of reactivity on substituents in the pyridine ring of the 4-methylpyridinium salts was studied in intermolecular reaction of ring transformation involving quaternary salts of pyridinium and isoquinolinium promoted by methylammonium sulfite.
- Gromov,Fomina,Grishina,Kurchavov
-
-
Read Online
- Discovery of 9,10-dihydrophenanthrene derivatives as SARS-CoV-2 3CLpro inhibitors for treating COVID-19
-
The epidemic coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has now spread worldwide and efficacious therapeutics are urgently needed. 3-Chymotrypsin-like cysteine protease (3CLpro) is an indispensable protein in viral replication and represents an attractive drug target for fighting COVID-19. Herein, we report the discovery of 9,10-dihydrophenanthrene derivatives as non-peptidomimetic and non-covalent inhibitors of the SARS-CoV-2 3CLpro. The structure-activity relationships of 9,10-dihydrophenanthrenes as SARS-CoV-2 3CLpro inhibitors have carefully been investigated and discussed in this study. Among all tested 9,10-dihydrophenanthrene derivatives, C1 and C2 display the most potent SARS-CoV-2 3CLpro inhibition activity, with IC50 values of 1.55 ± 0.21 μM and 1.81 ± 0.17 μM, respectively. Further enzyme kinetics assays show that these two compounds dose-dependently inhibit SARS-CoV-2 3CLpro via a mixed-inhibition manner. Molecular docking simulations reveal the binding modes of C1 in the dimer interface and substrate-binding pocket of the target. In addition, C1 shows outstanding metabolic stability in the gastrointestinal tract, human plasma, and human liver microsome, suggesting that this agent has the potential to be developed as an orally administrated SARS-CoV-2 3CLpro inhibitor.
- Zhang, Jian-Wei,Xiong, Yuan,Wang, Feng,Zhang, Fu-Mao,Yang, Xiaodi,Lin, Guo-Qiang,Tian, Ping,Ge, Guangbo,Gao, Dingding
-
-
- Cobalt-catalyzed cross-coupling of nitrogen-containing heterocyclic phosphonium salts with arylmagnesium reagents
-
Cobalt-catalyzed cross-couplings of nitrogen-containing heterocyclic phosphonium salts with arylmagnesium halides proceeded efficiently with the aid of cobalt(II) catalyst and copper(I) salt in tetrahydrofuran at ambient temperature, producing the desired
- Cui, Yan-Ying,Na, Jin-He,Guo, Meng-Meng,Huang, Jie-Ying,Chu, Xue-Qiang,Rao, Weidong,Shen, Zhi-Liang
-
supporting information
(2022/02/16)
-
- A Dichotomy in Cross-Coupling Site Selectivity in a Dihalogenated Heteroarene: Influence of Mononuclear Pd, Pd Clusters, and Pd Nanoparticles-The Case for Exploiting Pd Catalyst Speciation
-
Site-selective dihalogenated heteroarene cross-coupling with organometallic reagents usually occurs at the halogen proximal to the heteroatom, enabled by intrinsic relative electrophilicity, particularly in strongly polarized systems. An archetypical exam
- Eyles, Anthony,Fairlamb, Ian J. S.,Ford, Mark J.,Jeddi, Neda,Scott, Neil W. J.,Simon, Lauriane,Tanner, Theo,Whitwood, Adrian C.,Willans, Charlotte E.
-
supporting information
p. 9682 - 9693
(2021/07/19)
-
- Construction of a Pyrimidine Framework through [3 + 2 + 1] Annulation of Amidines, Ketones, and N, N-Dimethylaminoethanol as One Carbon Donor
-
An efficient, facile, and eco-friendly synthesis of pyrimidine derivatives has been developed. It involves a [3 + 2 + 1] three-component annulation of amidines, ketones, and one carbon source. N,N-Dimethylaminoethanol is oxidized through C(sp3)-H activation to provide the carbon donor. One C-C and two C-N bonds are formed during the oxidative annulation process. The reaction shows good tolerance to many important functional groups in air, making this methodology a highly versatile alternative, and significant improvement to the existing methods for structuring a pyrimidine framework, especially 4-aliphatic pyrimidines.
- Qin, Zemin,Ma, Yongmin,Li, Fanzhu
-
p. 13734 - 13743
(2021/10/12)
-
- Sustainable and recyclable magnetic nanocatalyst of 1,10-phenanthroline Pd(0) complex in green synthesis of biaryls and tetrazoles using arylboronic acids as versatile substrates
-
A magnetic nanocatalyst was purveyed as a heterogeneous recoverable palladium-based catalyst anchored on green, sustainable and phosphine free support. Resulted Fe3O4@SiO2-Phen-Pd(0) nanocatalyst bearing powerful phenanthroline ligand was thoroughly characterized by physicochemical approaches like UV–vis, FT-IR, EDX, XRD, TGA, ICP, VSM, DLS, FESEM, and TEM analyses. After finding trustable data, the obtained magnetic catalyst was considered to be applied in the Suzuki-Miyaura type C-C couplings and getting corresponding tetrazoles using arylboronic acid derivatives as alternate precursors of aromatic halides and stupendous data were observed.
- Bagherzadeh, Nastaran,Sardarian, Ali Reza,Eslahi, Hassan
-
-
- Green and sustainable palladium nanomagnetic catalyst stabilized by glucosamine-functionalized Fe3O4@SiO2 nanoparticles for Suzuki and Heck reactions
-
A novel magnetic and heterogeneous palladium-based catalyst stabilized by glucosamine-functionalized magnetic Fe3O4@SiO2 nanoparticle was synthesized. The strategy relies on the covalently bonding of glucosamine to cyanuric chloride-functionalized magnetic nanoparticles followed by complexation with palladium. The structure of magnetic nanocatalyst was fully determined by FT-IR, XRD, DLS, FE-SEM, TEM, ICP, UV-Vis, TGA, VSM, and EDX. The obtained results confirmed that the palladium nanoparticles stabilized by glucosamine immobilized onto the magnetic support exhibited high activity in cross-coupling reactions of Suzuki-Miyaura and Mizoroki-Heck. Various aryl halides were coupled with arylboronic acid (Suzuki cross-coupling reaction) and olefins (Heck reactions) under the green conditions to provide corresponding products in high to excellent yields. Interestingly, the catalyst can be easily isolated from the reaction media by magnetic decantation and can subsequently be applied for consecutive reaction cycles (at least seven times) with no notable reduction in the catalytic activity.
- Eslahi, Hassan,Sardarian, Ali Reza,Esmaeilpour, Mohsen
-
-
- Decarboxylative cyclization of amino acids towards the Regioselective synthesis of 2,4-diarylpyridines via relay Fe(III)/In(III)-catalysis
-
A competent relay Fe(III)-/In(III)-catalyzed decarboxylative cyclization of amino acids has been devised towards the exclusive preparation of 2,4-diarylpyridines. The efficacy of the developed conditions drives the reaction towards selective formation of 2,4-diarylpyridines over other pyridine derivatives. The described protocol showed good functional group tolerance with moderate to good yields of products.
- Gujjarappa, Raghuram,Vodnala, Nagaraju,Malakar, Chandi C.
-
supporting information
(2019/12/24)
-
- Palladium-Catalyzed Electrophilic Functionalization of Pyridine Derivatives through Phosphonium Salts
-
Herein, we report a highly efficient and practical method for pyridine-derived heterobiaryl synthesis through palladium-catalyzed electrophilic functionalization of easily available pyridine-derived quaternary phosphonium salts. The nice generality of this reaction was goes beyond arylation, enabling facile incorporation of diverse carbon-based fragments, including alkenyl, alkynyl, and also allyl fragments, onto the pyridine core. Notably, the silver salt additive is revealed to be of vital importance for the success of this transformation and its pivotal role as transmetallation mediator, which guarantees a smooth transfer of pyridyl group to palladium intermediate, is also described.
- Che, Yuan-Yuan,Deng, Xuezu,Feng, Chao,Lin, Ling-Zhi,Pei, Bingbing,Yue, Yanni
-
supporting information
p. 16414 - 16419
(2020/07/20)
-
- Palladium-catalyzed c-4 selective coupling of 2,4-dichloropyridines and synthesis of pyridine-based dyes for live-cell imaging
-
An alternative process of Pd-catalyzed C-4 selective coupling of 2,4-dichloropyridines with boronic esters was developed, which afforded 24 examples of C-4 coupled pyridines in moderate to good yields. After further arylation, 21 examples of C-2, C-4 diarylated pyridines with a significant photophysical property were obtained, which were applied as pyridine-based dyes into live-cell imaging with good biocompatibility and low toxicity.
- Chen, Jing,Ding, Yechun,He, Chen,Hu, Xin,Huang, Qitong,Kuang, Ying,Liu, Jinbiao,Yang, Min
-
p. 6498 - 6508
(2020/06/09)
-
- Pd-Catalyzed Decarboxylation and Dual C(sp3)-H Functionalization Protocols for the Synthesis of 2,4-Diarylpyridines
-
The Pd-catalyzed decarboxylation and dual C(sp3)-H bond functionalization approaches have been described for the preparation of symmetrical and unsymmetrical 2,4-diarylpyridines. The developed transformations were realized using nonactivated aromatic ketones and amino acids as C-N sources. The efficacy of the catalyst and reagent combination drives the transformation toward the formation of desired products with high yields and selectivity. The described reaction conditions have seduced the self-reaction of phenylalanine via [2 + 2 + 2] cycloaddition and minimized the formation of 3,5-phenylpyridine as a side product, whereas using glycine as a C-N source, the corresponding 2,6-diarylpyridines were formed as minor products.
- Gujjarappa, Raghuram,Vodnala, Nagaraju,Kumar, Mohan,Malakar, Chandi C.
-
p. 5005 - 5020
(2019/04/25)
-
- Organic Electroluminescence Device
-
The present invention relates to an organic electroluminescence device containing a dopant compound and a host compound in a specific combination. The organic electroluminescence device according to the present invention shows yellowish green luminescence
- -
-
Paragraph 0100-0103
(2019/11/29)
-
- Novel combination of host compound and dopant compound and organic electroluminescence device comprising same
-
The present invention relates to a specific combination of a dopant compound and a host compound, and an organic electroluminescent device comprising the same. The organic electroluminescent device ofthe present invention emits yellow-green light; lowers the driving voltage of the device by improving the current characteristic of the device; and improves power efficiency and operational lifespan.
- -
-
Paragraph 0087-0090
(2019/12/10)
-
- C6-Selective Direct Arylation of 2-Phenylpyridine via an Activated N-methylpyridinium Salt: A Combined Experimental and Theoretical Study
-
An elegant pre-activation strategy, based on the formation of N-methylpyridinium iodide salts for C6-selective direct arylation of 2-phenylpyridines using Pd/Cu cooperative catalysis, has been developed. By this methodology, a wide range of unsymmetrical 2, 6-diarylpyridines were synthesized with high reactivity and regioselectivity as well as good functional group tolerance. In particular, challenging substrates bearing electron donating groups (EDGs), such as OMe, NMe2, were also successfully employed in this reaction. Deuterium incorporation studies revealed that the C?H bond acidity is improved significantly in N-methylpyridinium salts compared with their N-Oxide and N-iminopyridinium ylide counterparts, thus solving the long-standing problem associated with previous strategies for the synthesis of diaryl pyridines. Finally, the control experiments and DFT calculations supported a Pd-catalyzed and Cu-mediated mechanism in which a carbenoid copper species that is formed in-situ from N-methylpyridinium salts, participates in a Pd-catalyzed arylation followed by an iodide-promoted N-demethylation process. (Figure presented.).
- Yin, Changzhen,Zhong, Kangbao,Li, Wenjing,Yang, Xiao,Sun, Rui,Zhang, Chunchun,Zheng, Xueli,Yuan, Maolin,Li, Ruixiang,Lan, Yu,Fu, Haiyan,Chen, Hua
-
supporting information
p. 3990 - 3998
(2018/09/12)
-
- ORGANIC COMPOUND AND ORGANIC LIGHT-EMITTING ELEMENT USING THE SAME
-
PROBLEM TO BE SOLVED: To provide a compound which has an electron-donating property and is stable in the atmosphere. SOLUTION: The organic compound is represented by general formula [1] (where n represents an integer from 0 to 3 inclusive; R1 and R4 each represent an alkyl group or an aryl group selected from a phenyl group, a naphthyl group, a biphenyl group, a terphenyl group, a phenanthrenyl group, a fluorenyl group, and a fluoranthenyl group; when R1 or R4 is an aryl group, the aryl group may further have an alkyl group; R2 and R3 each represent an alkyl group or an aryl group selected from a phenyl group, a naphthyl group, a biphenyl group, a terphenyl group, a phenanthryl group, a fluorenyl group, and a fluoranthenyl group; when R2 or R3 is an aryl group, the aryl group may further have an alkyl group, a phenyl group, or a naphthyl group; when R1 and R4 are alkyl groups, R2 and R3 are aryl groups; and when R2 and R3 are alkyl groups, R1 and R4 are aryl groups). SELECTED DRAWING: None COPYRIGHT: (C)2017,JPO&INPIT
- -
-
Paragraph 0145-0148
(2017/07/01)
-
- Synthesis of polysubstituted pyridines from oxime acetates using NH4I as a dual-function promoter
-
Pyridine formation with oxime acetates as the building blocks under metal-free conditions is described. Ammonium iodide has proved to be a highly efficient promoter for oxime N-O bond reduction and subsequent condensation reactions, whereby it played a dual-function role in the transformation. While the three-component reaction of oxime acetates, benzaldehydes, and 1,3-dicarbonyls proceeded well with the assistance of a stoichiometric amount of ammonium iodide, the condensation of oximes and acroleins was enabled by using a catalytic initiator to afford substituted pyridines. By this protocol, substituted pyridine products were generated in moderate to excellent yields with tolerance towards a broad range of functional groups.
- Xia, Yujia,Cai, Jinhui,Huang, Huawen,Deng, Guo-Jun
-
p. 124 - 129
(2017/12/27)
-
- Ruthenium Complexes Immobilized on Functionalized Knitted Hypercrosslinked Polymers as Efficient and Recyclable Catalysts for Organic Transformations
-
A hypercrosslinked polymer (HCP)-immobilized ruthenium catalyst (HCP–PPh3–Ru) was prepared from benzene and triphenylphosphine (PPh3) through a one-step external cross-linking reaction. The structure and composition of the catalyst were fully characterized by many physicochemical methods. HCP–PPh3–Ru was found to possess high Brunauer–Emmett–Teller (BET) surface area, large pore volume, and low skeletal density. Moreover, the Ru catalyst was also featured some advantages, such as low synthetic cost and good chemical and thermal stability. HCP–PPh3–Ru was then used as a recoverable and effective catalyst for the synthesis of 2,4-diaryl-substituted pyridines from acetophenones, ammonium acetate (NH4OAc) and dimethylformamide (DMF), and the cycloaddition reaction of diazodicarbonyl compounds with olefins to afford dihydrofurans. In addition, a combination of HCP–PPh3–Ru and Amberlyst-15 enabled us to establish a simple protocol for the direct synthesis of carbazole derivatives from diazodicarbonyl compound, alkyl vinyl ether and indole. In these selected reactions, the catalyst was easily recovered and reused several times without significant activity loss. (Figure presented.).
- Jia, Zhifang,Wang, Kewei,Tan, Bien,Gu, Yanlong
-
-
- The use of organolithium reagents for the synthesis of 4-aryl-2-phenylpyridines and their corresponding iridium(III) complexes
-
A versatile palladium-free route for the synthesis of 4-aryl-substituted phenylpyridines (ppy), starting from tert-butyl 4-oxopiperidine-1-carboxylate, is reported. Reaction with an aryllithium, followed by trifluoroacetic acid dehydration/deprotection and oxidation with 2-iodoylbenzoic acid and finally phenylation, gave 4 ligands (L1-4H): 2,4-diphenylpyridine, 4-(4-methoxyphenyl)-2-phenylpyridine, 2-phenyl-4-(o-tolyl)pyridine and 4-mesityl-2-phenylpyridine. These ligands were coordinated to iridium to give the corresponding Ir(L)2(A) complexes (Ir1-7), where A = ancillary ligand acetylacetate or 2-picolinate. This was used to demonstrate that, through a combination of ancillary ligand choice and torsional twisting between the 4-aryl substituents of the ppy ligands, it is possible to tune the phosphorescent emission of the complexes in the range 502-560 nm.
- Davidson, Ross,Hsu, Yu-Ting,Batchelor, Thomas,Yufit, Dmitry,Beeby, Andrew
-
p. 11496 - 11507
(2016/07/26)
-
- Iron-Catalyzed Cyclization of Ketoxime Carboxylates and Tertiary Anilines for the Synthesis of Pyridines
-
A novel and efficient iron-catalyzed cyclization of ketoxime carboxylates and N,N-dialkylanilines for the modular synthesis of diverse pyridines was developed. The reaction was initiated by Fe-catalyzed N-O bond cleavage of ketoxime carboxylates in the presence of tertiary anilines. The methylene carbon on N,N-dialkylanilines functioned as a source of one-carbon synthon in the reaction. The reaction used readily available starting materials, tolerated various functional groups, and afforded 2,4-disubstituted and 2,4,6-trisubstituted pyridines in good to high yields under mild conditions.
- Zhao, Mi-Na,Ren, Zhi-Hui,Yu, Le,Wang, Yao-Yu,Guan, Zheng-Hui
-
supporting information
p. 1194 - 1197
(2016/03/15)
-
- Route to Highly Substituted Pyridines
-
Pyridine rings are common structural motifs found in a number of biologically active compounds, including some top-selling pharmaceuticals. We have developed a new approach to access substituted pyridines. The method aims to provide a reliable synthesis of a diverse range of substituted pyridines through a three-step procedure. Readily available enones are first converted into 1,5-dicarbonyls through a two-step Hosomi-Sakurai allylation/oxidative cleavage sequence, which is followed by subsequent cyclization to the corresponding pyridine using hydroxylamine hydrochloride. A variety of substituted pyridines have been synthesized using this method.
- Hilf, Justin A.,Holzwarth, Michael S.,Rychnovsky, Scott D.
-
p. 10376 - 10382
(2016/11/17)
-
- Metal-Free Assembly of Polysubstituted Pyridines from Oximes and Acroleins
-
Transition-metal-catalyzed synthesis of N-heterocycles from oximes has been previously well established. In this paper, for the first time a metal-free protocol with the combinational employment of iodine and triethylamine has been demonstrated to be effective to trigger the oxime-based synthesis of pyridines with high chemo-selectivity and wide functional group tolerance. A broad range of functional pyridines were prepared in moderate to excellent yields. While neither iodine nor triethylamine could trigger this transformation, mechanistic experiments indicated a radical pathway for the reaction. The resultant 2-aryl-substituted pyridines have been proved to be versatile building blocks in a range of transition-metal-catalyzed C-H functionalization reactions. (Chemical Equation Presented).
- Huang, Huawen,Cai, Jinhui,Tang, Lichang,Wang, Zilong,Li, Feifei,Deng, Guo-Jun
-
p. 1499 - 1505
(2016/03/01)
-
- An Efficient Synthesis of Polysubstituted Pyridines via C sp 3 -H Oxidation and C-S Cleavage of Dimethyl Sulfoxide
-
An expedient cleavage of the C-S bond of dimethyl sulfoxide (DMSO) has been developed for the preparation of substituted pyridines from ketones. In this transformation, the co-product formic acid was formed from ammonium formate, which acted as an important catalyst for the reaction. Notably, this transformation exhibited a broad substrate scope towards a wide variety of different ketones to give the corresponding substituted pyridines in high yields. Mechanistic studies suggested that dimethyl sulfoxide delivered a methylene fragment, which was subsequently captured in situ to give a pyridine.
- Wu, Xia,Zhang, Jingjing,Liu, Shan,Gao, Qinghe,Wu, Anxin
-
p. 218 - 225
(2016/02/16)
-
- Synthesis of diverse di- to penta-substituted 1,2-dihydropyridine derivatives from gold(I)-catalyzed intramolecular addition of tertiary enamides to alkynes
-
As 3-aza-1,5-enynes, internal and terminal alkyne-bearing tertiary enamides underwent an efficient Au(I)-catalyzed 6-endo-dig cyclization reaction to afford a variety of di- to penta-substituted 1,2-dihydropyridine derivatives in high yields. The cyclizat
- Zhang, Xingyi,Xu, Xin-Ming,Zhao, Liang,You, Jingsong,Zhu, Jieping,Wang, Mei-Xiang
-
p. 3898 - 3901
(2015/06/08)
-
- Cobalt(III)-Catalyzed Directed C-H Coupling with Diazo Compounds: Straightforward Access towards Extended π-Systems
-
The first highly efficient and scalable cobalt-catalyzed directed C-H functionalization with carbene precursors is presented. This methodology provides a modular route towards a new class of conjugated polycyclic hydrocarbons with tunable emission wavelengths both in solution and in the solid state.
- Zhao, Dongbing,Kim, Ju Hyun,Stegemann, Linda,Strassert, Cristian A.,Glorius, Frank
-
supporting information
p. 4508 - 4511
(2015/04/14)
-
- The host compound and a new combination and dopant compd. organic electroluminescence device including the same
-
The present invention relates to a specific combination of a dopant compound and a host compound, and an organic electroluminescent device comprising the same. The organic electroluminescent device of the present invention emits yellow-green light; lowers
- -
-
Paragraph 0101-0104
(2016/10/08)
-
- Ammonium iodide-promoted cyclization of ketones with DMSO and ammonium acetate for synthesis of substituted pyridines
-
A simple and efficient method has been developed for the synthesis of symmetrical and unsymmetrical pyridines via NH4I-promoted cyclization of ketones with DMSO and NH4OAc. It was found that methyl ketones always gave selective forma
- Pan, Xiaojun,Liu, Qiao,Chang, Liming,Yuan, Gaoqing
-
p. 51183 - 51187
(2015/06/25)
-
- Synthesis of substituted pyridines from 1,2-nucleophilic addition products of functionalized N-acyl-2,3-dihydropyridones
-
Abstract We describe herein a general and efficient synthetic approach toward substituted pyridines from functionalized N-acyl-2,3-dihydropyridones in two steps; 1,2-addition with organocerium reagents and subsequent oxidative aromatization with chloranil
- Guzel, Mustafa,Watts, Joshua,Mcgilvary, Matthew,Wright, Marcus,Kiren, Sezgin
-
supporting information
p. 5275 - 5277
(2015/08/26)
-
- Synthesis of 2,4-diarylsubstituted-pyridines through a Ru-catalyzed four component reaction
-
A ruthenium-catalyzed one-pot synthesis of 2,4-diarylsubstituted pyridines from acetophenones, ammonium acetate and DMF under an oxygen atmosphere is described. The carbon atom situated at C6 of the pyridine ring comes from the methyl group of DMF and the nitrogen atom comes from ammonium acetate.
- Bai, Yang,Tang, Lichang,Huang, Huawen,Deng, Guo-Jun
-
supporting information
p. 4404 - 4407
(2015/04/14)
-
- A new approach to pyridines through the reactions of methyl ketones with 1,2,4-triazines
-
A new route to prepare pyridine derivatives based on inverse electron demand Diels-Alder/retro-Diels-Alder reactions of ketones with 1,2,4-triazines is reported. It is the first time using methyl ketones directly as a dienophile to react with 1,2,4-triazines without enamine intermediates, which is complementary to the classical Boger reaction. This journal is
- Wang, Shu-Wen,Guo, Wei-Si,Wen, Li-Rong,Li, Ming
-
p. 59218 - 59220
(2015/02/19)
-
- Triarylbismuthanes as threefold aryl-transfer reagents in regioselective cross-coupling reactions with bromopyridines and quinolines
-
Cross-coupling studies using bromopyridines and bromoquinolines with triarylbismuths as threefold coupling reagents in substoichiometric amounts under Pd-catalysed conditions are disclosed. The reactivity was high with both mono- and dibromopyridyl substrates, and mono- and bis-couplings were carried out regioselectively. A library of monoaryl and diaryl pyridines was formed in high yields. A one-pot strategy provided a simple and straightforward synthesis of both symmetrical and unsymmetrical diarylpyridines. Arylations of 2-bromo- and 3-bromoquinolines were achieved with triarylbismuth reagents. This study demonstrates that triarylbismuths may be used as threefold arylating reagents for the synthesis of aryl pyridines and quinolines through couplings with bromopyridines and bromoquinolines under Pd-catalysed conditions. Copyright
- Rao, Maddali L.N.,Dhanorkar, Ritesh J.
-
p. 5214 - 5228
(2014/10/15)
-
- Copper-catalyzed direct C-H arylation of pyridine N-oxides with arylboronic esters: One-pot synthesis of 2-arylpyridines
-
The first example of the copper-catalyzed direct C-H arylation of pyridine N-oxides with arylboronic esters has been developed, leading to a wide range of 2-arylpyridines in a one-pot synthesis with moderate to good yields without an additional reductant. This transformation allows for rapid access to a variety of 2-arylpyridines using an inexpensive catalytic system that would be more difficult to access with traditional methods. Thus, this method represents a simple and practical procedure to access 2-arylpyridines.
- Shen, Yan,Chen, Jiuxi,Liu, Miaochang,Ding, Jinchang,Gao, Wenxia,Huang, Xiaobo,Wu, Huayue
-
supporting information
p. 4292 - 4295
(2014/04/17)
-
- One-pot synthesis of isoquinoline and related compounds via Cu-mediated tandem cross-coupling and cyclization
-
One-pot synthetic strategy has been developed to access isoquinolines and its analogs via Cu-mediated tandem cross-coupling and cyclization in good yields under mild reaction conditions. A mixture of suitably substituted α-bromoaldehyde, terminal alkyne, and aq NH3 in CuI/1,10-phenanathroline catalytic system afforded the 3-substituted isoquinoline regio-selectively in good to excellent yields.
- Dhara, Shubhendu,Singha, Raju,Nuree, Yasin,Ray, Jayanta K.
-
supporting information
p. 795 - 798
(2014/02/14)
-
- A modular approach toward the synthesis of 2,4-disubstituted pyridines
-
A number of 2,4-disubstituted pyridines have been synthesized using α,β,γ,δ-unsaturated aldehydes and ammonium chloride in the presence of triethylamine in acetonitrile solvent at 80 C under air balloon.
- Singha, Raju,Dhara, Shubhendu,Ray, Jayanta K.
-
p. 4841 - 4843
(2013/08/28)
-
- Palladium-catalyzed highly regioselective 2-arylation of 2,x-dibromopyridines and its application in the efficient synthesis of a 17β-HSD1 inhibitor
-
2,3- and 2,5-Dibromopyridines reacted with arylboronic acids, catalyzed by Pd(OAc)2/PPh3 in the presence of K2CO 3 in CH3CN/MeOH (2:1) at 50 C for 24 h, to afford 2-arylpyridines in good to high yield
- Zhou, Qizhong,Zhang, Bin,Su, Liangjun,Jiang, Tiansheng,Chen, Rener,Du, Tieqi,Ye, Yuyuan,Shen, Jianfen,Dai, Guoliang,Han, Deman,Jiang, Huajiang
-
p. 10996 - 11003
(2014/01/06)
-
- Ligand-dependent site-selective suzuki cross-coupling of 3,5-dichloropyridazines
-
General methods for the highly site-selective Suzuki monocoupling of 3,5-dichloropyridazines have been discovered. By changing the ligand employed, the preferred coupling site can be switched from the 3-position to the 5-position, typically considered the less reactive C-X bond. These conditions are applicable to the coupling of a wide variety of aryl-, heteroaryl-, and vinylboronic acids with high selectivities, thus enabling the rapid construction of diverse arrays of diarylpyradazines in a modular fashion.
- Dai, Xing,Chen, Yonggang,Garrell, Stephanie,Liu, Hong,Zhang, Li-Kang,Palani, Anandan,Hughes, Gregory,Nargund, Ravi
-
p. 7758 - 7763
(2013/09/02)
-
- Modular pyridine synthesis from oximes and enals through synergistic copper/iminium catalysis
-
We describe here a [3+3]-type condensation reaction of O-acetyl ketoximes and α,β-unsaturated aldehydes that is synergistically catalyzed by a copper(I) salt and a secondary ammonium salt (or amine). This redox-neutral reaction allows modular synthesis of a variety of substituted pyridines under mild conditions with tolerance of a broad range of functional groups. The reaction is driven by a merger of iminium catalysis and redox activity of the copper catalyst, which would initially reduce the oxime N-O bond to generate a nucleophilic copper(II) enamide and later oxidize a dihydropyridine intermediate to the pyridine product.
- Wei, Ye,Yoshikai, Naohiko
-
supporting information
p. 3756 - 3759
(2013/04/23)
-
- Catalytic arylation of a C-H bond in pyridine and related six-membered N-heteroarenes using organozinc reagents
-
Despite significant advances in the catalytic direct arylation of heteroarenes, the application of this reaction to pyridines has been met with limited success. An oxidative nucleophilic arylation strategy has been developed to overcome this problem. Pyridine, pyrazine, quinolone, and related electron-deficient N-heteroarenes can be arylated at the most electrophilic site using the developed nickel-catalyzed reaction. This protocol serves as a complementary method to catalytic direct arylation reactions. Less is more: Pyridine, pyrazine, quinoline and related electron-deficient N-heteroarenes can be arylated at the most electrophilic site using organozinc reagents through nickel catalysis. This protocol serves as a complementary method to catalytic direct arylation reactions. Copyright
- Hyodo, Isao,Tobisu, Mamoru,Chatani, Naoto
-
supporting information; experimental part
p. 1357 - 1365
(2012/08/08)
-
- Cyclization reactions of 3,4-diazaheptatrienyl metal compounds. Pyridines from an anionic analogue of the Fischer indole synthesis: Experiment and theory
-
Unsymmetrical N,N′-bisalkylidene hydrazines 7a,b, 10a-c and 13, which are accessible in good to excellent yields from hydrazones 6, 9, and 12 and commercially available α,β-unsaturated carbonyl compounds, are converted into 3,4-diazaheptatrienyl anions 14
- Kleine, Tillmann,Froehlich, Roland,Wibbeling, Birgit,Wuerthwein, Ernst-Ulrich
-
p. 4591 - 4599
(2011/07/30)
-
- The synthesis and photophysics of tris-heteroleptic cyclometalated iridium complexes
-
Herein we report the synthesis and photophysical study of tris-heteroleptic complexes of the general formula IrLL′(acac), where L and L′ are two differently substituted 2-phenylpyridines (ppyH) and acacH is 2,4-pentanedione, using a combinatorial approach that could be employed for many ligand combinations. The tris-heteroleptic complexes and the analogous bis-heteroleptic complexes of the form IrL2(acac) have been studied by a combination of absorption and photoluminescence spectroscopies in conjunction with modelling by DFT and TD-DFT to elucidate the nature and location of the excited state in the novel species.
- Edkins, Robert M.,Wriglesworth, Alisdair,Fucke, Katharina,Bettington, Sylvia L.,Beeby, Andrew
-
supporting information; experimental part
p. 9672 - 9678
(2011/12/13)
-
- Simple selective synthesis of 2,4- and 2,6-diarylpyridines through metal-free cyclocondensation of aromatic ketones with ammonium acetate
-
A simple and selective one-pot synthesis of 2,4- and 2,6-diarylpyridines through the cyclocondensation reaction of aromatic ketones with ammonium acetate has been developed. The procedure is metal-free, convenient, and efficient, and the substrates are re
- Liu, Jin,Wang, Chuanxin,Wu, Liansheng,Liang, Fen,Huang, Guosheng
-
experimental part
p. 4228 - 4234
(2011/02/22)
-
- Efficient, mild and completely regioselective synthesis of substituted pyridines
-
Addition of Grignard reagents to pyridine N-oxides in THF at low temperature (-78 to -20 °C) and treatment with TFAA provides an efficient general procedure for synthesis of substituted pyridines. The method is compatible with a range of functional groups such as esters, halogens and nitriles.
- Andersson, Hans,Sainte-Luce Banchelin, Thomas,Das, Sajal,Olsson, Roger,Almqvist, Fredrik
-
supporting information; experimental part
p. 3384 - 3386
(2010/07/06)
-
- A dramatic substituent effect in silver(I)-catalyzed regioselective cyclization of ortho-alkynylaryl aldehyde oxime derivatives
-
A dramatic substituent effect was found in the silver(I)-catalyzed cyclization reaction of ortho-alkynylaryl aldehyde oxime derivatives. When R is an alkyl group, the Ag(I)-catalyzed reaction in dimethylacetamide at 110°C (conditions A) affords isoquinoli
- Gao, Hongyin,Zhang, Junliang
-
supporting information; experimental part
p. 85 - 88
(2009/10/02)
-
- Nickel-catalyzed reaction of arylzinc reagents with N-aromatic heterocycles: A straightforward approach to C-H bond arylation of electron-deficient heteroaromatic compounds
-
(Chemical Equation Presented) The reaction of electron-deficient N-heteroaromatic compounds, such as pyridines and quinolines, with arylzinc reagents in the presence of a catalytic amount of a nickel complex affords the arylated products. The reaction is likely to proceed through a formal nucleophilic 1,2-addition, thus exhibiting a reactivity complementary to conventional direct arylation through electrophilic substitution.
- Tobisu, Mamoru,Hyodo, Isao,Chatani, Naoto
-
supporting information; experimental part
p. 12070 - 12071
(2009/12/27)
-
- Synthesis of 2-substituted pyridines via a regiospecific alkylation, alkynylation, and arylation of pyridine N-oxides
-
Figure presented Sequential addition of Grignard reagents to pyridine N-oxides in THF at room temperature followed by treatment with acetic anhydride at 120°C afforded 2-substituted pyridines in good to high yields. Furthermore, by exchanging acetic anhydride for DMF in the second step, 2-substituted pyridine N-oxides were obtained, as intermediates suitable for addition of a second Grignard reagent for the synthesis of 2,6-disubstituted pyridines.
- Andersson, Hans,Almqvist, Fredrik,Olsson, Roger
-
p. 1335 - 1337
(2008/01/03)
-
- Regioselectivity in alkenyl(aryl)-heteroaryl Suzuki cross-coupling reactions of 2,4-dibromopyridine. A?synthetic and mechanistic study
-
2,4-Dibromopyridine undergoes a regioselective Suzuki cross-coupling reaction at position 2 with several alkenyl(aryl) boronic acids to render 4-bromo-2-carbon substituted pyridines, difficult to be prepared otherwise, in good yields under palladium catal
- Sicre, Cristina,Alonso-Gómez, J.-Lorenzo,Cid, M. Magdalena
-
p. 11063 - 11072
(2007/10/03)
-
- Direct synthesis of 4,4-disubstituted N-silyl-1,4-dihydropyridines
-
An unprecedented method for the preparation of 4,4-disubstituted 1,4-dihydropyridines is presented. It is based on the trapping reaction of 4-substitued N-silylpyridinium ions. When performed with dialkylmagnesium reagents, such as iPr2Mg, silyl protected 4,4-disubstituted 1,4-dihydropyridines were obtained in up to quantitative yields. High 1,4-selectivity was found for sterically demanding nucleophiles, whereas small nucleophiles (Me2Mg) tend to yield 1,2-addition-products. Grignard, dialkylzinc and organocopper reagents were found to give either no addition products or less favorable results. Reduction of the obtained 1,4-dihydropyridine with NaCNBH3 in the presence of HCl, followed by treatment with tert-butyl dicarbonate provided the corresponding N-Boc protected piperidines with high yields.
- Br?ckow, Jan,Wanner, Klaus T.
-
p. 2395 - 2404
(2007/10/03)
-
- Solid phase synthesis of heterocycles
-
Methods for solid phase and combinatorial synthesis using a resin activation/capture approach are provided. In particular, methods for the production of dihydropyridones, N-acyidihydropyridones, tetrahydropyridones, pyridines, aminopyridines, N-acyltetrah
- -
-
-
