13152-94-8Relevant academic research and scientific papers
Tetra- And Dinuclear Palladium Complexes Based on a Ligand of 2,8-Di-2-pyridinylanthyridine: Preparation, Characterization, and Catalytic Activity
Lin, Shih-Chieh Aaron,Liu, Shiuh-Tzung,Liu, Yi-Hung,Peng, Shie-Ming,Su, Bo-Kai
, p. 2081 - 2089 (2021/07/26)
Complexation of L [L = 5-phenyl-2,8-di-2-pyridinyl-anthyridine] with [Pd(CH3CN)4](BF4)2 and [Pd(CH3CN)3Cl](BF4) in a molar ratio of 1:2 rendered the corresponding dinuclear complexes [Pd2L (CH3CN)4](BF4)4 (1) and [Pd2L (CH3CN)2Cl2](BF4)2 (2), respectively. However, treatment of L with (COD)PdCl2 followed by anion exchange yielded a tetranuclear complex [Pd4L3Cl4](PF6)4(4a). Structures of these complexes are characterized by both spectroscopy and X-ray crystallography. Interconversion of these three complexes was studied via the manipulation of stoichiometric ratio of ligand to metal precursor. The catalytic activity of these complexes for carbonylative Suzuki-Miyaura cross-coupling was investigated. Complex 2 shows an excellent catalytic activity on the reaction of aryl iodide with arylboronic acid in the presence of atmospheric pressure of CO to give the corresponding benzophenones.
Supported Palladium-Catalyzed Carbonylative Synthesis of Diaryl Ketones from Aryl Bromides and Arylboronic Acids
Xu, Tiefeng,Wang, Qi,Yang, Zeyi,Yi, Lili,Wang, Jian-Shu,Lu, Wangyang,Ying, Jun,Wu, Xiao-Feng
supporting information, p. 2027 - 2030 (2021/06/21)
A palladium supported on graphitic carbon nitride (Pd/g-C3N4) catalyzed carbonylative reaction of aryl bromides and arylboronic acids by has been developed for the construction of diaryl ketones. Using benzene-1,3,5-triyl triformate (TFBen) as the CO source, the reaction proceeded well to give various diaryl ketones in moderate to good yields.
Carbonylative Suzuki coupling reactions catalyzed by ONO pincer–type Pd(II) complexes using chloroform as a carbon monoxide surrogate
Layek, Samaresh,Agrahari, Bhumika,Ganguly, Rakesh,Das, Parthasarathi,Pathak, Devendra D.
, (2020/01/25)
Benzoylhydrazone Schiff base–ligated three new ONO pincer–type palladium(II) complexes, [(PdL1(PPh3)] (1), [(PdL2(PPh3)] (2), and [(PdL3(PPh3)] (3), were synthesized by the reaction of the respective ligand, N-(2-hydroxybenzylidene)benzohydrazide (HL1), N-(2-hydroxy-3-methoxybenzylidene)benzohydrazide (HL2), or N-(5-bromo-2-hydroxybenzylidene) benzohydrazide (HL3), with Pd(OAc)2 and PPh3 in methanol and isolated as air-stable reddish-orange crystalline solids in high yields (78%–83%). All three complexes were fully characterized by elemental analysis, Fourier-transform infrared spectroscopy, UV–Visible, 1H nuclear magnetic resonance (NMR), 13C{1H} NMR, and 31P{1H} NMR spectroscopic studies. The molecular structure of all three complexes was established unambiguously by single-crystal X-ray diffraction studies which revealed a distorted square planar geometry of all three complexes. The ONO pincer–type ligands occupied three coordination sites at the palladium, while the fourth site is occupied by the monodentate triphenylphosphine ligand. The catalytic potential of all three complexes was explored in the carbonylative Suzuki coupling of aryl bromides and iodides with arylboronic acids to yield biaryl ketones, using CHCl3 as the source of carbonyl. The reported protocol is convenient and safe as it obviates the use of carbon monoxide (CO) balloons or pressured CO reactors which are otherwise needed for the carbonylation reactions. The methodology has been successfully applied to the synthesis of two antineoplastic drugs, namely, phenstatin and naphthylphenstatin, in good yields (81% and 85%, respectively). Under the optimized reaction conditions, complex 2 exhibited the best catalytic activity in the carbonylative Suzuki couplings. The reported catalysts have wide reaction scope with good functional group tolerance. All catalysts could be retrieved from the reaction after completion and recycled up to three times with insignificant loss in the catalytic activity.
Ligand-free Palladium-Catalyzed Carbonylative Suzuki Coupling of Aryl Iodides in Aqueous CH3CN with Sub-stoichiometric Amount of Mo(CO)6 as CO Source
Sun, Nan,Sun, Qingxia,Zhao, Wei,Jin, Liqun,Hu, Baoxiang,Shen, Zhenlu,Hu, Xinquan
, p. 2117 - 2123 (2019/03/28)
A new method for the synthesis of diaryl and heterodiaryl ketones has been established based on the palladium-catalyzed carbonylative Suzuki coupling approach with sub-stoichiometric Mo(CO)6 as CO source. Using 0.5 mol% of Pd(TFA)2 as catalyst, 0.5 equivalent of Mo(CO)6 as solid carbonyl reagent and 3 equivalent of K3PO4 as base, a wide range of functionalized (hetero)aryl iodides and (hetero)aryl boronic acids could smoothly proceed the carbonylative cross-coupling reaction in aqueous CH3CN at 50 °C, affording the corresponding ketones in good to excellent yields. The newly developed method was easy to operate under mild conditions with high efficiency. (Figure presented.).
Redox-Neutral ortho Functionalization of Aryl Boroxines via Palladium/Norbornene Cooperative Catalysis
Li, Renhe,Liu, Feipeng,Dong, Guangbin
supporting information, p. 929 - 939 (2019/04/10)
Palladium/norbornene (Pd/NBE) cooperative catalysis, also known as the Catellani reaction, has become an increasingly useful method for site-selective arene functionalization; however, certain constraints still exist because of its intrinsic mechanistic pathway. Herein, we report a redox-neutral ortho functionalization of aryl boroxines via Pd/NBE catalysis. An electrophile, such as carboxylic acid anhydrides or O-benzoyl hydroxylamines, is coupled at the boroxine ortho position, and a proton as the second electrophile is introduced at the ipso position. This reaction does not require extra oxidants or reductants and avoids stoichiometric bases or acids, thereby tolerating a wide range of functional groups. In particular, orthogonal chemoselectivity between aryl iodide and boroxine moieties is demonstrated, which could be used to control reaction sequences. Finally, a deuterium-labeling study supports the ipso protonation pathway. This unique mechanistic feature could inspire the development of a new class of Pd/NBE-catalyzed transformations.Poly-substituted aromatics are ubiquitously found in drugs and agrochemicals. To realize streamlined synthesis, it is highly attractive if functional groups can be site-selectively introduced at unactivated positions with common arene starting materials. Here, a method is developed to directly introduce acyl and amino groups at unactivated ortho positions of readily available aryl boron compounds. Compared with the known ortho functionalization approaches, this method does not require stoichiometric bases, external oxidants, or reductants. Consequently, the reaction is chemoselective: a wide range of functional groups, including highly reactive aryl iodides, can be tolerated. The primary innovation lies in the use of a proton to terminate the ipso aryl intermediate and regenerate the active palladium catalyst. This unique mode of reactivity in the palladium/norbornene catalysis should open the door for developing new redox-neutral methods for site-selective arene functionalization.A redox-neutral ortho functionalization of aryl boroxines via palladium/norbornene cooperative catalysis is developed. The ortho amination and acylation are achieved with carboxylic acid anhydrides and O-benzoyl hydroxylamines as an electrophile, respectively, whereas protonation occurs at the ipso position. This transformation avoids using either extra oxidants and reductants or stoichiometric bases and acids. In addition, orthogonal chemoselectivity between aryl iodide and boroxine moieties is demonstrated for pathway divergence.
Sequential Organozinc Formation and Negishi Cross-Coupling of Amides Catalysed by Cobalt Salt
Dorval, Céline,Dubois, Elodie,Bourne-Branchu, Yann,Gosmini, Corinne,Danoun, Grégory
supporting information, p. 1777 - 1780 (2019/02/26)
Herein, a cobalt-catalysed Negishi-type cross-coupling of amide derivatives is described. Apart from being the first example of cobalt-catalysed Negishi-type coupling of amides, the process described employs a unique, simple, and cheap catalytic system to perform both the organozinc formation and the Negishi-type coupling. Indeed, the same cobalt(II) bromide salt used to form the arylzinc species from aryl bromides is then re-used to perform the cross coupling of this resulting arylzinc with N-benzoyl glutarimides at room temperature. The main advantages of the reaction presented are its robustness and ease of use. Indeed, the reactions of organozinc formation and Negishi-type coupling are performed without precautions toward water or oxygen. (Figure presented.).
Highly efficient synthesis of aryl ketones by PEPPSI-palladium catalyzed acylative Suzuki coupling of amides with diarylborinic acids
Wang, Chen,Huang, Lingyun,Wang, Fengze,Zou, Gang
, p. 2299 - 2301 (2018/05/16)
An improved acylative cross-coupling of various N-methyl-N-tosyl amides with diarylborinic acids for synthesis of aryl ketones is developed. In most cases, aryl ketones could be obtained in excellent yields by using 1 mol% 2,6-diisopropylphenylimidazolylidene and 3-chloropyridine co-supported palladium chloride as catalyst in the presence of 3 equiv. K2CO3 as base in refluxing THF. The readily prepared and cost-effective substrates, N-methyl-N-tosylamides and diarylborinic acids, and the commercially available catalyst system promise a practical and efficient access to aryl ketones.
Pd-NHC catalysed Carbonylative Suzuki coupling reaction and its application towards the synthesis of biologically active 3-aroylquinolin-4 (1H)-one and acridone scaffolds
Ghosh, Prasanjit,Ganguly, Bhaskar,Das, Sajal
, (2018/03/01)
We have unfolded a convenient and mild protocol for the synthesis of diaryl ketones via Pd- NHC catalysed carbonylative Suzuki coupling reaction. Notably, this method offers advantages like no use of toxic CO gas, shorter reaction time, high yield, and broad substrate scope. Several sensitive functional groups (like-COMe, -COOMe, -F, -Cl, -Br, -NH2, -CN) are well tolerated in this reaction. In addition, we have also demonstrated a new efficient route for the synthesis of biologically active and pharmaceutically important 2-substituted 3-Aroylquinolin-4(1H)-ones and acridone scaffolds.
A synthesis of biaryl ketones via the C–S bond cleavage of thiol ester by a Cu/Ag salt
Ghosh, Prasanjit,Ganguly, Bhaskar,Das, Sajal,Perl, Eliyahu
, p. 2751 - 2756 (2017/06/23)
We report the synthesis of biaryl ketones via an unprecedented copper/silver catalyzed acylative cross-coupling of thiol esters with either an arylboronic acid or a potassium aryltrifluoroborate. This new method proceeds without a requisite Pd-catalyst and Cu(I)TC mediator, and is efficient, versatile, operationally simple, and accommodating functionally diverse thiol esters, arylboronic acids, and potassium aryltrifluoroborates.
Iron-catalyzed carbonylation of aryl halides with arylborons using stoichiometric chloroform as the carbon monoxide source
Zhao, Hongyuan,Du, Hongyan,Yuan, Xiaorong,Wang, Tianjiao,Han, Wei
supporting information, p. 5782 - 5787 (2016/11/06)
A general iron-catalyzed carbonylative Suzuki-Miyaura coupling of aryl halides with arylborons is reported, using stoichiometric CHCl3 as the CO source. The high efficiency, economy, selectivity, and operational simplicity of this transformation make this method a valuable tool in organic synthesis. Importantly, the presented strategy allows effective 13C labeling simply by using the commercially available 13C-labeled CHCl3. On the basis of the initial mechanistic exploration, an aryl radical intermediate is proposed in the present carbonylation process.
