92964-54-0Relevant articles and documents
Synthesis of Fluorenes and Dibenzo[ g,p]chrysenes through an Oxidative Cascade
Dickinson, Cody F.,Tius, Marcus A.,Yap, Glenn P. A.
, p. 1559 - 1563 (2022/02/07)
We have developed robust, operationally simple syntheses of fluorenes and of dibenzo[g,p]chrysenes through oxidative cascade processes. These structures that are commonly encountered in optoelectronic materials, dyes, and pharmaceutical products are acces
Coumarins by Direct Annulation: β-Borylacrylates as Ambiphilic C3-Synthons
Wienhold, Max,Molloy, John J.,Daniliuc, Constantin G.,Gilmour, Ryan
supporting information, p. 685 - 689 (2020/11/30)
Modular β-borylacrylates have been validated as programmable, ambiphilic C3-synthons in the cascade annulation of 2-halo-phenol derivatives to generate structurally and electronically diverse coumarins. Key to this [3+3] disconnection is the BPin unit which serves a dual purpose as both a traceless linker for C(sp2)–C(sp2) coupling, and as a chromophore extension to enable inversion of the alkene geometry via selective energy transfer catalysis. Mild isomerisation is a pre-condition to access 3-substituted coumarins and provides a handle for divergence. The method is showcased in the synthesis of representative natural products that contain this venerable chemotype. Facile entry into π-expanded estrone derivatives modified at the A-ring is disclosed to demonstrate the potential of the method in bioassay development or in drug repurposing.
Cost-effective bio-derived mesoporous carbon nanoparticles-supported palladium catalyst for nitroarene reduction and Suzuki–Miyaura coupling by microwave approach
Supriya,Ananthnag, Guddekoppa S.,Shetti, Vijayendra S.,Nagaraja,Hegde, Gurumurthy
, (2020/01/25)
A new heterogeneous catalyst was synthesized by immobilizing Pd on areca nut kernel-derived carbon nanospheres (CNSs). The CNSs, without any further activation processes, accommodated 3% of Pd on their surface. The new Pd/CNS material was used for the reduction of nitroarenes and Suzuki–Miyaura coupling of bromoarenes with aryl boronic acids. The reactions were conducted under microwave irradiation at 160 °C using 12 mol% of Pd/CNS (0.36% actual Pd content). The reduction of nitroarenes into their respective amino compounds was achieved in 10–20 min (conversion up to 100%); by contrast, the Suzuki–Miyaura reactions yielded up to 98% at 150 °C with 10 mol% of Pd/CNS catalyst. The products were identified using gas chromatography and nuclear magnetic resonance spectroscopy. The catalyst was isolated from reaction mixture and reused without any significant loss in the activity. Thus, the present work introduces one-pot-derived porous CNSs as efficient catalytic support to Pd, establishing an alternative to existing Pd/C in terms of cost and efficiency.
Galloyl esters of trans-stilbenes are inhibitors of FASN with anticancer activity on non-small cell lung cancer cells
Tan, Yu-Jia,Ali,Tee, Sheng-Yang,Teo, Jun-Ting,Xi, Yu,Go, Mei-Lin,Lam
, (2019/08/20)
Fatty acid synthase (FASN) is a lipogenic enzyme that is selectively upregulated in malignant cells. There is growing consensus on the oncogenicity of FASN-driven lipogenesis and the potential of FASN as a druggable target in cancer. Here, we report the synthesis and FASN inhibitory activities of two novel galloyl esters of trans-stilbene EC1 and EC5. Inhibition of FASN was accompanied by a loss in AKT activation and profound apoptosis in several non-small cell lung cancer (NSCLC) cells at the growth inhibitory concentrations of EC1 and EC5. Both FASN and phospho-AKT levels were concurrently downregulated. However, addition of a lipid concentrate to the treated cells reinstated cell viability and reversed the loss of FASN and AKT protein levels, thus recapitulating the causal relationship between FASN inhibition and the loss in cell viability.
An acetatopalladium(II) complex with 1-benzyl-N-(3,5-di-tert-butylsalicylidene)piperidin-4-amine: Synthesis, structure and catalytic applications in Suzuki–Miyaura coupling of arylboronic acids with hydroxyaryl halides
Keesara, Srinivas,Narendra Babu,Pal, Samudranil
, (2017/09/30)
The Schiff base 1-benzyl-N-(3,5-di-tert-butylsalicylidene)piperidin-4-amine (HL) and its acetatopalladium(II) complex having the formula [Pd(L)(OAc)] were synthesized. Both HL and [Pd(L)(OAc)] were characterized using elemental analysis and various spectroscopic (infrared, UV–visible, 1H NMR and 13C NMR) and mass spectrometric measurements. The molecular structure of the complex was determined using X-ray crystallographic analysis. In the complex, the pincer-like NNO-donor L? and the monodenate OAc? provide a distorted square-planar N2O2 coordination environment around the metal centre. The physicochemical properties and the spectroscopic features of [Pd(L)(OAc)] are consistent with its molecular structure. The complex was found to be an effective catalyst for the Suzuki–Miyaura cross-coupling reactions of hydroxyaryl halides with arylboronic acids in predominantly aqueous media. The reactions afforded hydroxybiaryl products in good to excellent yields with a wide substrate scope.
Heterogeneous Catalysis by Covalent Organic Frameworks (COF): Pd(OAc)2@COF-300 in Cross-Coupling Reactions
Gon?alves, Raoni S. B.,Deoliveira, Alline B. V.,Sindra, Haryadylla C.,Archanjo, Bráulio S.,Mendoza, Martín E.,Carneiro, Leonardo S. A.,Buarque, Camilla D.,Esteves, Pierre M.
, p. 743 - 750 (2016/03/05)
COF-300, an imine-linked, crystalline, and microporous covalent organic framework, modified by coordination of Pd(OAc)2 to its walls, afforded a hybrid material, Pd(OAc)2@COF-300, which was used as an efficient heterogeneous catalyst for cross-coupling reactions. This material showed excellent catalytic activity for the phosphine-free Suzuki-Miyaura, Heck, and Sonogashira cross-coupling reactions with low palladium loadings (0.1mol % Pd). X-ray photoelectron spectroscopy analysis of the catalyst after the reaction showed that PdII is converted to Pd0, which is trapped within the COFs nanopores. This was confirmed by high-resolution transmission electron microscopy. Moreover, promising results were obtained using Pd(OAc)2@COF-300 under continuous-flow conditions for a Suzuki-Miyaura cross-coupling reaction.
A divergent and selective synthesis of ortho- and para-quinones from phenols
Huang, Zheng,Kwon, Ohhyeon,Esguerra, Kenneth Virgel N.,Lumb, Jean-Philip
, p. 5871 - 5885 (2015/08/04)
Abstract We describe a divergent synthesis of substituted ortho- and para-quinones by catalytic aerobic oxygenation of phenols. Substituted quinones are omnipresent in chemistry and biology, but their synthesis frequently suffers from low efficiency and poor scope. Our methodology employs a catalytic aerobic di-functionalization of phenols to aryloxy-ortho-quinones. Regioselective substitution with an alcohol provides the alkoxy substituted ortho- or para-quinone, while hydrolysis affords the para-hydroxyquinone. These are mild and selective conditions for the synthesis of diversely substituted quinones from readily available phenol starting materials.
Excited state intramolecular proton transfer (ESIPT) from phenol to carbon in selected phenylnaphthols and naphthylphenols
Basari?, Nikola,Do?li?, Nacrossed D Signa,Ivkovi?, Jakov,Wang, Yu-Hsuan,Veljkovi?, Jelena,Mlinari?-Majerski, Kata,Wan, Peter
, p. 1811 - 1823 (2013/04/10)
ESIPT and solvent-assisted ESPT in isomeric phenyl naphthols and naphthyl phenols 5-8 were investigated by preparative photolyses in CH 3CN-D2O, fluorescence spectroscopy, LFP, and ab initio calculations. ESIPT takes place only in 5 (D-exchange Φ = 0.3), whereas 6-8 undergo solvent-assisted PT with much lower efficiencies. The efficiency of the ESIPT and solvent-assisted PT is mainly determined by different populations of the reactive conformers in the ground state and the NEER principle. The D-exchange experiments and calculations using RI-CC2/cc-pVDZ show that 5 in S1 deactivates by direct ESIPT from the OH to the naphthalene position 1 through a conical intersection with S0, delivering QM 14 that was detected by LFP (τ = 26 ± 3 ns). ESIPT to position 3 in 5 is possible but it proceeds from a less-populated conformer and involves an energy barrier on S1. In solvent-assisted PT to naphthalene position 4 in 5, zwitterion 17 is formed, which cyclizes to stable naphthofuran photoproducts 9-12. The regiochemistry of the deuteration in solvent-assisted PT was correlated with the NBO charges of the corresponding phenolates/naphtholates 5--8-. Combined experimental and theoretical data indicate that solvent-assisted PT takes place via a sequential mechanism involving first deprotonation of the phenol/naphthol, followed by the protonation by H 2O in the S1 state of phenolate/naphtholate. The site of protonation by H2O is mostly at the naphthalene α-position.
A highly practical and reliable nickel catalyst for Suzuki-Miyaura coupling of aryl halides
Zhao, Yu-Long,Li, You,Li, Shui-Ming,Zhou, Yi-Guo,Sun, Feng-Yi,Gao, Lian-Xun,Han, Fu-She
supporting information; experimental part, p. 1543 - 1550 (2011/08/07)
We disclose that [1,3-bis(diphenylphosphino)methane]nickel(II) chloride [NiCl2(dppp)] is a highly active, universally applicable, cheap, and stable catalyst for Suzuki-Miyaura cross-coupling reactions of aryl halides with a catalyst loading of lower than 1 mol%, and more notably, in the absence of extra supporting ligands. Under the optimized reaction conditions, a broad range of aryl bromides as well as the notoriously unreactive aryl chlorides, including activated, non-activated, deactivated, and heteroaromatic and sterically hindered substrates can be coupled smoothly with various boronic acids (47 examples, 48-98% yields). In addition, the transformation is tolerant of various functional groups such as ether, ester, ketone, aldehyde, cyano, and unprotected amino and hydroxy groups. Finally, the potential utilization of the methodology was further demonstrated by the gram-scale synthesis of several core structures of commercialized antihypertensive drugs and fungicides. Thus, the combination of high activity, broad applicability, cheapness, and high stability of NiCl2(dppp) presented in this work constitutes one of the few prominent catalysts which allow for practical and reliable construction of biaryls and heterobiaryls with structural diversity from readily available aryl halides and boronic acids. Copyright
An efficient protocol for the palladium-catalysed Suzuki-Miyaura cross-coupling
Marziale, Alexander N.,Jantke, Dominik,Faul, Stefan H.,Reiner, Thomas,Herdtweck, Eberhardt,Eppinger, Joerg
supporting information; experimental part, p. 169 - 177 (2011/03/23)
The palladacyclic catalyst precursor received by ortho-palladation of ([1,1′-biphenyl]-2-yloxy)diisopropyl-phosphine represents a highly active system for Suzuki-Miyaura cross-coupling reactions when used in neat water. An efficient, broadly applicable and sustainable aqueous protocol was developed using 2.5 eq. of Na2CO3 as base, allowing the reaction to be performed under air and at ambient temperature with Pd loadings of 0.04 mol%. Coupling products are obtained in high yields and excellent purity by simple filtration with no organic solvents needed throughout the whole reaction. A broad variety of functional groups are tolerated and a large number of substrates can be applied with this protocol. The crystal structure of the palladacyclic catalyst precursor is presented as well as investigations targeting the nature of catalyst activation and the active catalytic species.