- Cobalt Corroles as Electrocatalysts for Water Oxidation: Strong Effect of Substituents on Catalytic Activity
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Two Co(III) complexes (1Py2 and 2Py2) of new corrole ligands H3L1 (5,15-bis(p-methylcarboxyphenyl)-10-(o-methylcarboxyphenyl)corrole) and H3L2 (5,15-bis(p-nitrophenyl)-10-(o-methylcarboxyphenyl)corrole) with two apical pyridine ligands have been synthesized and thoroughly characterized by cyclic voltammetry, UV-vis-NIR, and EPR spectroscopy, spectroelectrochemistry, single-crystal X-ray diffraction studies, and DFT methods. Complexes 1Py2 and 2Py2 possess much lower oxidation potentials than cobalt(III)-tris-pentafluorophenylcorrole (Co(tpfc)) and similar corroles containing pentafluorophenyl (C6F5) substituents, thus allowing access to high oxidation states of the former metallocorroles using mild chemical oxidants. The spectroscopic (UV-vis-NIR and EPR) and electronic properties of several oxidation states of these complexes have been determined by a combination of the mentioned methods. Complexes 1Py2 and 2Py2 undergo three oxidations within 1.3 V vs FcH+/FcH in MeCN, and we show that both complexes catalyze water oxidation in an MeCN/H2O mixture upon the third oxidation, with kobs (TOF) values of 1.86 s-1 at 1.29 V (1Py2) and 1.67 s-1 at 1.37 V (2Py2). These values are five times higher than previously reported TOF values for C6F5-substituted cobalt(III) corroles, a finding we ascribe to the additional charge in the corrole macrocycle due to the increased oxidation state. This work opens up new possibilities in the study of metallocorrole water oxidation catalysts, particularly by allowing spectroscopic probing of high-oxidation states and showing strong substituent-effects on catalytic activity of the corrole complexes.
- Neuman, Nicolás I.,Albold, Uta,Ferretti, Eleonora,Chandra, Shubhadeep,Steinhauer, Simon,R?ner, Paul,Meyer, Franc,Doctorovich, Fabio,Vaillard, Santiago E.,Sarkar, Biprajit
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- Design, synthesis and pharmacological evaluation of N-benzyl-piperidinyl-aryl-acylhydrazone derivatives as donepezil hybrids: Discovery of novel multi-target anti-alzheimer prototype drug candidates
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A new series of sixteen multifunctional N-benzyl-piperidine-aryl-acylhydrazones hybrid derivatives was synthesized and evaluated for multi-target activities related to Alzheimer's disease (AD). The molecular hybridization approach was based on the combination, in a single molecule, of the pharmacophoric N-benzyl-piperidine subunit of donepezil, the substituted hydroxy-piperidine fragment of the AChE inhibitor LASSBio-767, and an acylhydrazone linker, a privileged structure present in a number of synthetic aryl- and aryl-acylhydrazone derivatives with significant AChE and anti-inflammatory activities. Among them, compounds 4c, 4d, 4g and 4j presented the best AChE inhibitory activities, but only compounds 4c and 4g exhibited concurrent anti-inflammatory activity in vitro and in vivo, against amyloid beta oligomer (AβO) induced neuroinflammation. Compound 4c also showed the best in vitro and in vivo neuroprotective effects against AβO-induced neurodegeneration. In addition, compound 4c showed a similar binding mode to donepezil in both acetylated and free forms of AChE enzyme in molecular docking studies and did not show relevant toxic effects on in vitro and in vivo assays, with good predicted ADME parameters in silico. Overall, all these results highlighted compound 4c as a promising and innovative multi-target drug prototype candidate for AD treatment.
- Dias Viegas, Flávia Pereira,de Freitas Silva, Matheus,Divino da Rocha, Miguel,Castelli, Maísa Rosa,Riquiel, Mariana Máximo,Machado, Rafael Pereira,Vaz, Sarah Macedo,Sim?es de Lima, Laís Medeiros,Mancini, Karla Cristine,Marques de Oliveira, Patrícia Cruz,Morais, élida Parreira,Gontijo, Vanessa Silva,da Silva, Fernanda Motta R.,D'Alincourt da Fonseca Pe?anha, Dora,Castro, Newton Gon?alves,Neves, Gilda A.,Giusti-Paiva, Alexandre,Vilela, Fabiana Cardoso,Orlandi, Lidiane,Camps, Ihosvany,Veloso, Márcia Paranho,Leomil Coelho, Luis Felipe,Ionta, Marisa,Ferreira-Silva, Guilherme álvaro,Pereira, Rodrigo Machado,Dardenne, Laurent E.,Guedes, Isabella Alvim,de Oliveira Carneiro Junior, Wellerson,Quaglio Bellozi, Paula Maria,Pinheiro de Oliveira, Ant?nio Carlos,Ferreira, Fábio Furlan,Pruccoli, Letizia,Tarozzi, Andrea,Viegas, Claudio
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- Electronic and electrochemical properties as well as flowerlike supramolecular assemblies of fulleropyrrolidines bearing ester substituents with different alkyl chain lengths
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A series of alkyl (methyl, ethyl, propyl, butyl) benzoate ester substituted fulleropyrrolidine derivatives (FP1-FP4) were synthesized and their electronic and electrochemical properties were investigated by means of absorption spectra, electronic structure calculation, and cyclic voltammetry (CV), respectively. The LUMO-HOMO energies and energy gaps of fullerene derivatives were estimated by the first reduction potential measured with CV combined with absorption spectra, which are consistent with those obtained from density functional theory (DFT) calculations. It was found that all fulleropyrrolidines showed very similar absorption spectra, orbital energies and redox behaviors, which are comparable with those of well-known phenyl-C61-butyric acid methyl ester (PCBM). The flowerlike supramolecular architectures obtained from the self-assembly of FP1-FP4 in chloroform-alcohol mixture solvents were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). A lamellar structure with a d-spacing of 1.92-2.02 nm that depends on the molecular size, corresponding to the thickness of a bilayer structure, suggested a face-to-face conformation of the substituent of C60 and an interdigitation of the bare C60 side packing. These fulleropyrrolidines have high C60 content, are energetically PCBM-like, and are capable of forming complex flowerlike architectures, which provide fundamental insights into molecular design toward advanced fullerene materials.
- Zhang, Xuan,Li, Xu-Dong,Ma, Li-Xia,Zhang, Bei
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- One-pot conversion of activated alcohols into terminal alkynes using manganese dioxide in combination with the Bestmann-Ohira reagent
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The direct conversion of activated primary alcohols into terminal alkynes through a sequential one-pot, two-step process involving oxidation with manganese dioxide and then treatment with the Bestmann-Ohira reagent is described. This transformation proceeds efficiently (59-99% yield) under mild reaction conditions with a range of benzylic, heterocyclic and propargylic alcohols. A tandem variant is also described, which is successful only with highly activated substrates.
- Quesada, Ernesto,Taylor, Richard J.K.
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- Endosome Targeting meso-Tetraphenylchlorin-Chitosan Nanoconjugates for Photochemical Internalization
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Four amphiphilic covalently linked meso-tetraphenylchlorin-chitosan nanoconjugates were synthesized and evaluated for use in photochemical internalization (PCI) in vitro and in vivo. The synthetic protocol for the preparation of two different hydrophobic chlorin photosensitizers, 5-(4-aminophenyl)-10,15,20-triphenylchlorin and 5-(4-carboxyphenyl)-10,15,20-triphenylchlorin, was optimized. These monofunctional photosensitizers were covalently attached to carrier chitosan via silyl-protected 3,6-di-O-tert-butyldimethylsilyl-chitosan (Di-TBDMS-chitosan) with 0.10 degree of substitution per glucosamine (DS). Hydrophilic moieties such as trimethylamine and/or 1-methylpiperazine were incorporated with 0.9 DS to give fully water-soluble conjugates after removal of the TBDMS groups. A dynamic light scattering (DLS) study confirmed the formation of nanoparticles with a 140-200 nm diameter. These nanoconjugates could be activated at 650 nm (red region) light, with a fluorescence quantum yield (ΦF) of 0.43-0.45, and are thus suitable candidates for use in PCI. These nanoconjugates were taken up and localized in the endocytic vesicles of HCT116/LUC human colon carcinoma cells, and upon illumination they substantially enhanced plasmid DNA transfection. The nanoconjugates were also evaluated in preliminary in vivo experiments in tumor-bearing mice, showing that the nanoconjugates could induce a strong photodynamic therapy (PDT) and also PCI effects in treatment with bleomycin.
- Gaware, Vivek S.,H?kerud, Monika,Juzeniene, Asta,H?gset, Anders,Berg, Kristian,Másson, Már
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- Synthesis of Carboxamide-Containing Tranylcypromine Analogues as LSD1 (KDM1A) Inhibitors Targeting Acute Myeloid Leukemia
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Lysine-specific demethylase 1 (LSD1/KDM1A) oxidatively removes methyl groups from histone proteins, and its aberrant activity has been correlated with cancers including acute myeloid leukemia (AML). We report a novel series of tranylcypromine analogues with a carboxamide at the 4-position of the aryl ring. These compounds, such as 5 a and 5 b with benzyl and phenethylamide substituents, respectively, had potent sub-micromolar IC50 values for the inhibition of LSD1 as well as cell proliferation in a panel of AML cell lines. The dose-dependent increase in cellular expression levels of H3K4me2, CD86, CD11b and CD14 supported a mechanism involving LSD1 inhibition. The tert-butyl and ethyl carbamate derivatives of these tranylcypromines, although inactive in LSD1 inhibition, were of similar potency in cell-based assays with a more rapid onset of action. This suggests that carbamates can act as metabolically labile tranylcypromine prodrugs with superior pharmacokinetics.
- Teresa Borrello, Maria,Benelkebir, Hanae,Lee, Adam,Hin Tam, Chak,Shafat, Manar,Rushworth, Stuart A.,Bowles, Kristian M.,Douglas, Leon,Duriez, Patrick J.,Bailey, Sarah,Crabb, Simon J.,Packham, Graham,Ganesan
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- Synthesis and properties of a meso- tris-ferrocene appended zinc(ii) porphyrin and a critical evaluation of its dye sensitised solar cell (DSSC) performance
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A zinc(ii) porphyrin derivative, F3P, was prepared containing a single ferrocene group appended at three of the meso positions. The final meso position contains a benzoic acid unit, and was designed to be an anchoring moiety to a semiconductor surface. The cyclic voltammogram for the porphyrin derivative reveals that the three ferrocene units are oxidised and reduced at E 1/2 = +0.04 V vs. Fc+/Fc. Other redox responses are porphyrin-based at +1.1 V vs. Fc+/Fc (irreversible) and -1.87 V and -2.20 V vs. Fc+/Fc (both quasi-reversible). The room temperature Moessbauer spectrum for F3P comprises a doublet (δ Fe 0.44 mm s -1; ΔEQ 2.35 mm s-1; peak width 0.27 mm s-1). The data are consistent with the ferrocene groups non-interacting with the porphyrin moiety in the ground state. Excitation of the compound in THF with an ultra-short laser pulse produces in less than 1 ps the charge separated state which comprises Fc+-porp- and decays back to the ground state in 24 ps. Roughly the same behaviour is observed for the dye absorbed on TiO2, the only slight difference is the appearance of a long-lived component in the decay records. The electron for the porphyrin radical anion does not inject into the conduction band of the TiO 2, only the porphyrin excited state participates in any electron injection process. Partly because of this factor the performance of the dye attached to TiO2 in a DSSC device is rather limited (JSC = 0.068 mA cm-2, VOC = 283 mV, FF = 0.42, η = 0.008%). This journal is the Partner Organisations 2014.
- Sirbu,Turta,Benniston,Abou-Chahine,Lemmetyinen,Tkachenko,Wood,Gibson
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- Highly atom efficient synthesis of 2,2,4,5-tetrasubstituted 3(2H)-furanones having both hydroxyl and amino substituents
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We have developed a highly atom efficient synthesis of tetrasubstituted 3(2H)-furanones from easily accessible starting materials such as C,N-diarylaldonitrones and dibenzoylacetylene. Control experiments revealed that reaction of aldonitrones having electron-withdrawing groups on the C-aryl substituent in polar aprotic solvents exhibited high product selectivity while reaction temperature has only a negligible effect on product yield and selectivity.
- Antony, Jesna,Mathai, Sindhu,Natarajan, Rakesh,P. Musthafa, Sumi,Rappai, John P.,S. Devaky, Karakkattu
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supporting information
(2022/02/25)
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- Zwitterion-induced organic-metal hybrid catalysis in aerobic oxidation
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In many metal catalyses, the traditional strategy of removing chloride ions is to add silver salts via anion exchange to obtain highly active catalysts. Herein, we reported an alternative strategy of removing chloride anions from ruthenium trichloride using an organic [P+-N-] zwitterionic compound via multiple hydrogen bond interactions. The resultant organic-metal hybrid catalytic system has successfully been applied to the aerobic oxidation of alcohols, tetrahydroquinolines, and indolines under mild conditions. The performance of zwitterion is far superior to that of many other common Lewis bases or Br?nsted bases. Mechanistic studies revealed that the zwitterion triggers the dissociation of chloride from ruthenium trichloride via nonclassical hydrogen bond interaction. Preliminary studies show that the zwitterion is applicable to catalytic transfer semi-hydrogenation.
- Hu, Rong-Bin,Lam, Ying-Pong,Ng, Wing-Hin,Wong, Chun-Yuen,Yeung, Ying-Yeung
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p. 3498 - 3506
(2021/04/07)
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- Method for preparing carbonyl compound by oxidizing alcohol
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The invention provides a method for preparing aldehyde or ketone by alcohol oxidation. Iron nitrate hydrate (Fe (NO) is used as a solvent. 3 )3 · 992 O). 4 - Hydroxyl -2, 2, 6, 6 - tetramethylpiperidine oxide (4 - OH-TEMPO) and carboxylic acid are catalysts, and the alcohol is oxidized to aldehydes or ketones with oxygen or air as an oxidizing agent. Compared with the prior art, water serves as a solvent, so that the pollution-free halogenated hydrocarbon or strong carcinogenic sodium nitrite (NaNO) is avoided. 2 The method is green and environment-friendly, the cost is greatly reduced, and the method is a method suitable for industrial production.
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Paragraph 0027
(2021/09/08)
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- 4CzIPN catalyzed photochemical oxidation of benzylic alcohols
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A green photoredox oxidation of benzylic primary and secondary alcohols to aldehydes and ketones with air as an oxidant was reported. The oxidation shows broad substrate scope and excellent selectivity over benzylic alcohols to the aliphatic alcohols. Further mechanistic studies revealed a quinuclidine mediated HAT process, and blue LEDs promoted 4CzlPN (1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene) photoredox cycle were involved in our oxidation.
- Zhang, Heng,Guo, Tianyun,Wu, Mingzhong,Huo, Xing,Tang, Shouchu,Wang, Xiaolei,Liu, Jian
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supporting information
(2021/02/20)
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- Mild oxidation of benzyl alcohols to benzyl aldehydes or ketones catalyzed by visible light
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Induced by visible light, mild oxidation condition to prepare benzyl aldehydes or ketones have been developed by using bromotrichloromethane as photochemical oxidant. This method avoids high temperature, pressure and peroxidation with only visible light as the green driving force.
- Cheng, Dongping,Li, Xiaonian,Ren, Shujian,Xu, Xiaoliang
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supporting information
(2021/07/02)
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- Cerium-photocatalyzed aerobic oxidation of benzylic alcohols to aldehydes and ketones
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We have developed a cerium-photocatalyzed aerobic oxidation of primary and secondary benzylic alcohols to aldehydes and ketones using inexpensive CeCl3 7H2O as photocatalyst and air oxygen as the terminal oxidant.
- K?nig, Burkhard,Kumar, Sumit,Stahl, Jessica,Yatham, Veera Reddy,Yedase, Girish Suresh
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supporting information
p. 1727 - 1732
(2021/08/05)
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- A new catalytic approach for aerobic oxidation of primary alcohols based on a Copper(I)-thiophene carbaldimines
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We report here novel Cu(I) thiophene carbaldimine catalysts for the selective aerobic oxidation of primary alcohols to their corresponding aldehydes and various diols to lactones or lactols. In the presence of the in situ generated Cu(I) species, a persistent radical (2,2,6,6-tetramethylpiperdine-N-oxyl (TEMPO)) and N-methylimidazole (NMI) as an auxiliary ligand, the reaction proceeds under aerobic conditions and at ambient temperature. Especially the catalytic system of 1-(thiophen-2-yl)-N-(4-(trifluoromethoxy)phenyl)methanimine (ligand L2) with copper(I)-iodide showed high reactivity for all kind of alcohols (benzylic, allylic and aliphatic). In the case of benzyl alcohol even 2.5 mol% of copper loading gave quantitative yield. Beside high activity under aerobic conditions, the catalysts ability to oxidize 1,5-pentadiol to the corresponding lactol (86% in 4 h) and N-phenyldiethanolamine to the corresponding morpholine derivate lactol (86% in 24 h) is particularly noteworthy.
- Lagerspets, Emi,Valbonetti, Evelyn,Eronen, Aleksi,Repo, Timo
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- Hydroxyl radical-mediated oxidative cleavage of CC bonds and further esterification reaction by heterogeneous semiconductor photocatalysis
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A hydroxyl radical-mediated aerobic cleavage of alkenes and further sequence esterification reaction for the preparation of carbonyl compounds have been developed by using tubular carbon nitride (TCN) as a general heterogeneous photocatalyst under an oxygen atmosphere with visible light irradiation. This protocol has an excellent substrate scope and gives the desired aldehydes, ketones and esters in moderate to high yields. Importantly, this metal-free procedure employed photogenerated hydroxyl radicals in situ as green oxidation active species, avoiding the present additional initiators. The reaction could be carried out under solar light irradiation and was applicable to large-scale reactions. Furthermore, the recyclable TCN catalyst could be used several times without a significant loss of activities.
- Hong, Mei,Jia, Rui,Miao, Hongyan,Ni, Bangqing,Niu, Tengfei,Wang, Hui
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p. 6591 - 6597
(2021/09/10)
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- New method for promoting photosensitive oxidation to remove 1, 2-mercaptoethanol acetal protecting group by utilizing visible light irradiation
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The invention discloses a new method for removing a 1, 2-mercaptoethanol acetal protecting group, and belongs to the field of organic synthetic chemistry. The method comprises the following steps of:under a room-temperature open system, adding a substrate 2-substituted-1, 3-oxo-thio-cyclopentane and a catalytic amount of a photosensitizer Eosin Y into a proper amount of acetonitrile; and performing irradiating with a blue LED lamp for 3 hours while stirring to obtain the corresponding aldehyde compound with favorable yield. The method has the advantages of mild operation conditions, greenness, environmental protection, no harsh water and oxygen removal operation and device, realization of the reaction at room temperature, high substrate conversion rate, simple and easy post-treatment, andprovides a good method for removing the 1, 2-mercaptoethanol acetal protecting group at present.
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Paragraph 0014-0016
(2021/01/30)
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- Ball-Milling-Enabled Reactivity of Manganese Metal**
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Efforts to generate organomanganese reagents under ball-milling conditions have led to the serendipitous discovery that manganese metal can mediate the reductive dimerization of arylidene malonates. The newly uncovered process has been optimized and its mechanism explored using CV measurements, radical trapping experiments, EPR spectroscopy, and solution control reactions. This unique reactivity can also be translated to solution whereupon pre-milling of the manganese is required.
- Bolt, Robert R. A.,Browne, Duncan L.,Howard, Joseph L.,Khan, Adam,Magri, Giuseppina,Morrill, Louis C.,Nicholson, William I.,Richards, Emma,Seastram, Alex C.
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supporting information
p. 23128 - 23133
(2021/09/20)
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- Dirhodium-Based Supramolecular Framework Catalyst for Visible-Light-Driven Hydrogen Evolution
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The direct conversion of solar energy to clean fuels as alternatives to fossil fuels is an important approach for addressing the global energy shortage and environmental problems. Here, we introduce a new dirhodium-complex-based framework assembly as a heterogeneous molecule-based photocatalyst for hydrogen evolution using visible light. Two dirhodium complexes bearing visible-light-harvesting BODIPY (boron dipyrromethene, BDP) moieties were newly designed and synthesized. The obtained complexes were self-assembled to framework structures (supramolecular framework catalysts), which are stabilized intermolecular noncovalent interactions. These frameworks retained excellent visible-light-harvesting properties of BDP moieties. Investigation of the catalytic performance of the supramolecular framework catalysts revealed that the supramolecular framework catalyst with heavy atoms at BDP moieties exhibited excellent performance in the formation of hydrogen with a reaction rate of 275.8 μmol g-1 h-1 under irradiation of visible light, whereas the supramolecular framework catalyst without heavy atoms at BDP moieties was inactive. Moreover, the system has the additional benefits of high durability (up to 96 h), reusability, and facile removal from the reaction mixture. We also disclosed the effect of heavy atoms at BDP moieties on the catalytic activity and proposed a reaction mechanism.
- Chinapang, Pondchanok,Iwami, Hikaru,Enomoto, Takafumi,Akai, Takuya,Kondo, Mio,Masaoka, Shigeyuki
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p. 12634 - 12643
(2021/08/03)
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- DIBALH: From known fundamental to an unusual reaction; Chemoselective partial reduction of tertiary amides in the presence of esters
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This study presents a quick and reliable approach to the chemoselective partial reduction of tertiary amides to aldehydes in the presence of readily reducible ester groups using commercial DIBALH reagent. Moreover, the developed method was also extended to multi-functional molecules bearing ester moieties, which were successfully chemoselectively reduced to the corresponding aldehydes. This journal is
- An, Duk Keun,Heo, Yu Jin,Jaladi, Ashok Kumar,Kim, Hyun Tae
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p. 33809 - 33813
(2021/12/09)
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- METHOD FOR OXIDATIVE CLEAVAGE OF COMPOUNDS WITH UNSATURATED DOUBLE BOND
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A method for oxidative cleavage of a compound with an unsaturated double bond is provided. The method comprises the following step: (A) providing a compound (I) with an unsaturated double bond, a reagent with trifluoromethyl, and a catalyst; wherein the catalyst is represented by the following formula (II): M(O)mL1yL2z (II); wherein, M, L1, L2, m, y, z, R1, R2 and R3 are defined in the specification; and (B) mixing the compound with an unsaturated double bond and the reagent with a trifluoromethyl to perform an oxidation of the compound with the unsaturated double bond by using the catalyst at air or an oxygen condition to get a compound presented as formula (III):
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Paragraph 0053-0054; 0062-0063
(2021/03/19)
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- Mild Copper-Catalyzed Addition of Arylboronic Esters to Di- tert -butyl Dicarbonate: An Easy Access to Methyl Arylcarboxylates
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An efficient copper-catalyzed addition of arylboronic esters to (Boc) 2O was developed. The reaction can be conducted under exceedingly mild conditions and is compatible with a variety of synthetically relevant functional groups. It therefore represents a useful alternative route for the synthesis of methyl arylcarboxylates. A preliminary mechanistic study indicated the involvement of an addition-elimination mechanism.
- Xu, Jin-Di,Su, Xiao-Bo,Wang, Cai,Yao, Li-Wei,Liu, Jing-Hui,Hu, Guo-Qin
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supporting information
p. 833 - 837
(2021/02/26)
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- Visible-Light-Promoted Metal-Free Synthesis of (Hetero)Aromatic Nitriles from C(sp3)?H Bonds**
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The metal-free activation of C(sp3)?H bonds to value-added products is of paramount importance in organic synthesis. We report the use of the commercially available organic dye 2,4,6-triphenylpyrylium tetrafluoroborate (TPP) for the conversion of methylarenes to the corresponding aryl nitriles via a photocatalytic process. Applying this methodology, a variety of cyanobenzenes have been synthesized in good to excellent yield under metal- and cyanide-free conditions. We demonstrate the scope of the method with over 50 examples including late-stage functionalization of drug molecules (celecoxib) and complex structures such as l-menthol, amino acids, and cholesterol derivatives. Furthermore, the presented synthetic protocol is applicable for gram-scale reactions. In addition to methylarenes, selected examples for the cyanation of aldehydes, alcohols and oximes are demonstrated as well. Detailed mechanistic investigations have been carried out using time-resolved luminescence quenching studies, control experiments, and NMR spectroscopy as well as kinetic studies, all supporting the proposed catalytic cycle.
- Murugesan, Kathiravan,Donabauer, Karsten,K?nig, Burkhard
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supporting information
p. 2439 - 2445
(2020/12/07)
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- Palladium-Catalyzed Reductive Carbonylation of (Hetero) Aryl Halides and Triflates Using Cobalt Carbonyl as CO Source
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An efficient protocol for the reductive carbonylation of (hetero) aryl halides and triflates under CO gas-free conditions using Pd/Co2(CO)8 and triethylsilane has been developed. The mild reaction conditions, enhanced chemoselectivity and, easy access to heterocyclic and vinyl carboxaldehydes highlights its importance in organic synthesis.
- Dogga, Bhushanarao,Joseph, Jayan T.,Kumar, C. S. Ananda
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supporting information
p. 309 - 313
(2020/12/23)
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- A Magnetically Recyclable Palladium-Catalyzed Formylation of Aryl Iodides with Formic Acid as CO Source: A Practical Access to Aromatic Aldehydes
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A magnetically recyclable palladium-catalyzed formylation of aryl iodides under CO gas-free conditions has been developed by using a bidentate phosphine ligand-modified magnetic nanoparticles-anchored- palladium(II) complex [2P-Fe 3O 4@SiO 2-Pd(OAc) 2] as catalyst, yielding a wide variety of aromatic aldehydes in moderate to excellent yields. Here, formic acid was employed as both the CO source and the hydrogen donor with iodine and PPh 3as the activators. This immobilized palladium catalyst can be obtained via a simple preparative procedure and can be facilely recovered simply by using an external magnetic field, and reused at least 9 times without any apparent loss of catalytic activity.
- You, Shengyong,Zhang, Rongli,Cai, Mingzhong
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p. 1962 - 1970
(2021/01/25)
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- Nickel catalyzed hydrosilane reduction of (het)arenecarboxylic acids into aldehydes
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Nickel-catalyzed reduction of (het)arenecarboxylic acids with hydrosilanes in the presence of dimethyl dicarbonate as the activator affords the corresponding aldehydes. The role of the activator is the conversion of the acids into their anhydrides undergoing C–O cleavage. The good yields were achieved in case of substrates bearing electron-donating and electron-neutral groups.
- Wang, Liang,Wang, Yaoyao,Tao, Yu,Zhang, Nana,Li, Shubai
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p. 271 - 273
(2021/05/04)
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- Decarboxylative formylation of aryl halides with glyoxylic acid by palladium catalysis under oxygen
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A new free radical/palladium cooperative catalyzed formylation of aryl halides with glyoxylic acid as the formyl source under oxygen conditions has been developed. Various aromatic and heteroaromatic aldehydes were produced in medium to good yields.
- Cao, Hualiang,Pu, Weiwen,Zhang, Jie,Yan, Peijun,Zhang, Jun,Xu, Sheng
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supporting information
p. 1287 - 1290
(2020/08/21)
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- Iodobenzene-catalyzed oxidative cleavage of olefins to carbonyl compounds
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A metal-free approach for the oxidative cleavage of carbon–carbon double bonds of olefins to carbonyl compounds was established by using oxidant m-CPBA and non-metallic organocatalyst PhI in toluene/H2O. A broad scope of aromatic olefins was used. All the reactions proceeded smoothly at 35 °C in short reaction time to furnish the respective mono- and double carbonyl compounds selectively in moderate to good yields.
- Du, Lele,Wang, Zechao,Wu, Junliang
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supporting information
(2020/07/20)
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- Polyamino acid carrier with acid-sensitive connecting arm in middle as well as preparation method and application of polyamino acid carrier
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The invention discloses a polyamino acid carrier with an acid-sensitive connecting arm in the middle as well as a preparation method and application of the polyamino acid carrier. The polyamino acid carrier contains a hydrophilic part, a hydrophobic part and a responsive connecting arm; a specific disulfide bond is introduced into the carrier design, the disulfide bond can be controllably broken into sulfydryl in vitro, the small molecule with the sulfydryl fragment or the gene with sulfydryl inherent on the surface is bonded with the protein drug again, and a covalent disulfide bond is formedto complete chemical bonding delivery of the drug. The polyamino acid carrier and the drug are bonded in a covalent bond manner, so that the drug can be stably transported in systemic circulation. When the carrier reaches high-metabolism and high-reducibility parts such as tumors or inflammations, disulfide bonds are broken again under the condition of high glutathione (GSH), and the activity ofthe drug is released and recovered. Therefore, the purposes of firstly masking the drug activity, then stably delivering the drug in vivo and recovering accurate regulation and control of the drug activity after the drug reaches a target position are achieved.
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Paragraph 0050; 0060-0061
(2020/09/20)
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- DIPHENYLAMINO-METHYLENE MALONONITRILE BASED COMPOUNDS AS FLUORESCENCE PROBES
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The present invention provides compounds of formula (I) and formula (II): or a pharmaceutically acceptable salt or a stereoisomer thereof; wherein, ring A and ring B have the meanings given in the specification. The compounds of the present disclosure are useful as fluorescence probe in detecting tubulin in a sample and therefore useful for the diagnosis of tubulin and its associated diseases like cancer in a subject.
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Page/Page column 20-21
(2020/03/23)
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- Free radical oxidation reaction for selectively solvatochromic sensors with dynamic sensing ability
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A novel BODIPY (boradiazaindacene) dye denoted as BODIPY-DT containing terpyridine unit has been designed and characterized. The dye is found to be selective and visual solvatochromic sensor toward DMF among test organic solvents. The sensing process displays time-controllable, dynamic signal outputs in the emission colors including red, purple, yellow and even white emission colors. It is presented that selective free radical oxidation reaction happens during the recognition process.
- Shen, Fengjuan,Wang, Tao,Yu, Xudong,Li, Yajuan
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supporting information
p. 1919 - 1922
(2019/12/27)
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- A Strategy for Accessing Aldehydes via Palladium-Catalyzed C?O/C?N Bond Cleavage in the Presence of Hydrosilanes
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We report the catalytic reduction of both active esters and amides by selective C(acyl)?X (X=O, N) cleavage to access aldehyde functionality via a palladium-catalyzed strategy. Reactions are promoted by hydrosilanes as reducing reagents with good to excellent yields and with excellent chemoselectivity for C(acyl)?N and C(acyl)?O bond cleavage. Carboxylic acid C(acyl)?O bonds are activated by 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) to form triazine ester intermediates, which further react with hydrosilanes to yield aldehydes in one-pot two-step procedures. We demonstrate that C(acyl)?O cleavage/formylation offers higher yields and broader substrate scopes compared with C(acyl)?N cleavage under the same reaction conditions.
- He, Zhanyu,Liu, Tingting,Ru, Junxiang,Wang, Yulin,Wang, Zijia,Zeng, Zhuo
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supporting information
p. 5794 - 5800
(2020/12/01)
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- Thiourea-Mediated Halogenation of Alcohols
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The halogenation of alcohols under mild conditions expedited by the presence of substoichiometric amounts of thiourea additives is presented. The amount of thiourea added dictates the pathway of the reaction, which may diverge from the desired halogenation reaction toward oxidation of the alcohol, in the absence of thiourea, or toward starting material recovery when excess thiourea is used. Both bromination and chlorination were highly efficient for primary, secondary, tertiary, and benzyl alcohols and tolerate a broad range of functional groups. Detailed electron paramagnetic resonance (EPR) studies, isotopic labeling, and other control experiments suggest a radical-based mechanism. The fact that the reaction is carried out at ambient conditions, uses ubiquitous and inexpensive reagents, boasts a wide scope, and can be made highly atom economic, makes this new methodology a very appealing option for this archetypical organic reaction.
- Mohite, Amar R.,Phatake, Ravindra S.,Dubey, Pooja,Agbaria, Mohamed,Shames, Alexander I.,Lemcoff, N. Gabriel,Reany, Ofer
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supporting information
p. 12901 - 12911
(2020/11/26)
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- Heterogeneous carbon nitride photocatalyst for C-C bond oxidative cleavage of vicinal diols in aerobic micellar medium
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A green and efficient visible-light promoted aerobic oxidative C-C bond cleavage of vicinal diols in micellar medium has been developed. This protocol used graphitic carbon nitride with nitrogen vacancies (CN620) as a metal-free recyclable photocatalyst and CTAB as surfactant in water. Control experiments and the ESR results indicated that superoxide radicals and valence band holes played an important role in the reaction. Further isotope experiments suggested both a β-scission/HAT pathway and an oxidation/hydrolysis/dehydration pathway for the reaction, which is different from previous reports. The semiconductor/micellar catalyst system can be recycled at least 10 times without a significant reduction in activity. Furthermore, this reaction could be carried out under solar light irradiation and was applicable to large-scale reactions with similar results.
- Chen, Jiayang,Chen, Shengjun,Dong, Xinyu,Hong, Mei,Ni, Bangqing,Niu, Tengfei,Zhang, Tianhao
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supporting information
p. 5042 - 5049
(2020/08/25)
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- Nitrile Synthesis by Aerobic Oxidation of Primary Amines and in situ Generated Imines from Aldehydes and Ammonium Salt with Grubbs Catalyst
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Herein, a Grubbs-catalyzed route for the synthesis of nitriles via the aerobic oxidation of primary amines is reported. This reaction accommodates a variety of substrates, including simple primary amines, sterically hindered β,β-disubstituted amines, allylamine, benzylamines, and α-amino esters. Reaction compatibility with various functionalities is also noted, particularly with alkenes, alkynes, halogens, esters, silyl ethers, and free hydroxyl groups. The nitriles were also synthesized via the oxidation of imines generated from aldehydes and NH4OAc in situ. (Figure presented.).
- Utsumi, Tatsuki,Noda, Kenta,Kawauchi, Daichi,Ueda, Hirofumi,Tokuyama, Hidetoshi
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p. 3583 - 3588
(2020/08/05)
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- Continuous flow synthesis of aryl aldehydes by Pd-catalyzed formylation of phenol-derived aryl fluorosulfonates using syngas
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This communication describes the palladium-catalyzed reductive carbonylation of aryl fluorosulfonates (ArOSO2F) using syngas as an inexpensive and sustainable source of carbon monoxide and hydrogen. The conversion of phenols to aryl fluorosulfonates can be conveniently achieved by employing the inexpensive commodity chemical sulfuryl fluoride (SO2F2) and base. The developed continuous flow formylation protocol requires relatively low loadings for palladium acetate (1.25 mol%) and ligand (2.5 mol%). Good to excellent yields of aryl aldehydes were obtained within 45 min for substrates containing electron withdrawing substituents, and 2 h for substrates containing electron donating substituents. The optimal reaction conditions were identified as 120 °C temperature and 20 bar pressure in dimethyl sulfoxide (DMSO) as solvent. DMSO was crucial in suppressing Pd black formation and enhancing reaction rate and selectivity. This journal is
- Hanselmann, Paul,Hone, Christopher A.,Hu, Guixian,K?ckinger, Manuel,Kappe, C. Oliver
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p. 22449 - 22453
(2020/07/03)
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- Visible light photoredox catalyzed deprotection of 1,3-oxathiolanes
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An efficient visible light photoredox catalyzed aerobic deprotection of 1,3-oxathiolanes using organic dye Eosin Y as a photocatalyst is disclosed. The deprotection procedure features the use of a metal-free catalyst, mild conditions, a broad range of substrate scope, and good functional group tolerance. 35 examples were tested under the standard conditions and most of them afforded the deprotected products in modest to high yields.
- Yang, Mingyang,Xing, Zhimin,Fang, Bowen,Xie, Xingang,She, Xuegong
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supporting information
p. 288 - 291
(2020/01/13)
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- A Remote ‘Imidazole’-Based Ruthenium(II) Para-Cymene Pre-catalyst for the Selective Oxidation Reaction of Alkyl Arenes and Alcohols
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Herein we disclosed the use of a remote ‘imidazole’-based precatalyst [(para-cymene)RuII(L)Cl]+, C-1 where L=2-(4-substituted-phenyl)-1H-imidazo[4,5-f][1,10] phenanthroline) for the selective oxidation of a variety of alkyl arenes/heteroarenes and alcohols to their corresponding aldehydes or ketones in presence of tert-butyl hydroperoxide (TBHP). The remote ‘imidazole’ moiety present in the complex facilitates the activation of oxidant and subsequent generation of active species via the release of para-cymene from C-1, which in-turn was less effective without the ‘imidazole’ moiety. The mechanistic features of C-1 promoted oxidation of alkyl arenes were also assessed from spectroscopic, kinetic, and few control experiments. The substrate scope for C-1 promoted oxidation reaction was assessed based on the selective oxidation of 27-different alkyl arenes/heteroarenes and 25 different alcohols to their corresponding aldehydes/ketones in moderate to good yields.
- Dutta, Manali,Bania, Kusum K.,Pratihar, Sanjay
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p. 926 - 932
(2020/03/05)
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- A Simple, Mild and General Oxidation of Alcohols to Aldehydes or Ketones by SO2F2/K2CO3 Using DMSO as Solvent and Oxidant
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A practical, general and mild oxidation of primary and secondary alcohols to carbonyl compounds proceeds in yields of up to 99% using SO2F2 as electrophile in DMSO as both the oxidant and the solvent at ambient temperature. No moisture- and oxygen-free conditions are required. Stoichiometric amount of inexpensive K2CO3, which generates easy to separate by-products, is used as the base. Thus, 5-gram scale runs proceeded in nearly quantitative yields by a simple filtration as the work-up. The use of a polar solvent such as DMSO, which usually promotes competing Pummerer rearrangement, is also noteworthy. This protocol is compatible with a variety of common N-, O-, and S-functional groups on (hetero)arene, alkene and alkyne substrates (68 examples). The protocol was applied (99% yield) to a formal synthesis of the important cholesterol-lowering drug Rosuvastatin. (Figure presented.).
- Zha, Gao-Feng,Fang, Wan-Yin,Leng, Jing,Qin, Hua-Li
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supporting information
p. 2262 - 2267
(2019/04/17)
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- Iron-Catalyzed Aerobic Oxidation of Alcohols: Lower Cost and Improved Selectivity
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An aerobic oxidation reaction of alcohols toward aldehydes or ketones using catalytic amounts of Fe(NO3)3·9H2O, 4-OH-TEMPO, and NaCl has been developed. Compared with the former catalytic system with TEMPO developed in this group, the new protocol using 4-OH-TEMPO, which is much cheaper on an industrial scale, accomplished the transformation with a higher selectivity, especially for aliphatic alcohols toward aldehydes. α,β-Unsaturated alkynals or alkynones can be efficiently synthesized from propargyl alcohols, which has been much less studied in the literature.
- Jiang, Xingguo,Liu, Jinxian,Ma, Shengming
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p. 825 - 835
(2019/05/02)
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- A method for the preparation of aldehydes
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The invention discloses a method for the preparation of ketone, relates to the field of organic synthesis. This invention adopts the organic solvent as a medium, cyclopropene [...] derivative as an active agent, activated DMSO oxidation [...] oxidation. The method of the invention is simple, easy to operate, rapid reaction rate, mild reaction, the reaction rate can be adjusted, more economic, to achieve industrial laid the foundation.
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Paragraph 0104; 0105
(2019/05/28)
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- Copper(I)- and Mesoionic-Hydroxyamide-Catalyzed Chemoselective Aerobic Oxidation of Primary Benzylic Alcohols
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A new aerobic oxidation system consisting of Cu(I)I, 2,2'-bipyridine, N -methyl imidazole, and a mesoionic hydroxyamide was developed, with which selective oxidation of a broad range of benzylic alcohols was achieved.
- Matsukawa, Yuta,Hirashita, Tsunehisa
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p. 315 - 318
(2019/02/12)
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- A Transition-Metal-Free One-Pot Cascade Process for Transformation of Primary Alcohols (RCH2OH) to Nitriles (RCN) Mediated by SO2F2
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A new transition-metal-free one-pot cascade process for the direct conversion of alcohols to nitriles was developed without introducing an “additional carbon atom”. This protocol allows transformations of readily available, inexpensive, and abundant alcohols to highly valuable nitriles.
- Jiang, Ying,Sun, Bing,Fang, Wan-Yin,Qin, Hua-Li
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supporting information
p. 3190 - 3194
(2019/05/21)
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- Photocatalytic coupled redox cycle for two organic transformations over Pd/carbon nitride composites
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Heterogeneous photocatalysis offers a means for "green" organic transformations. Generally, photogenerated electrons and holes are not utilized simultaneously and effectively. Here we report a coupling approach to promote simultaneously two organic transformations of the Ullmann C-C coupling reaction and the value-added aromatic alcohol oxidation reaction in inert solvent and under anaerobic conditions using a carbon nitride based composite (Pd/CN-450) prepared by loading Pd nanoparticles (NPs) on CN-450 (N defect and O dopant co-modified g-C3N4 with high crystallinity). Upon photo-excitation of the photocatalyst, the activation of carbon-halogen bonds of the adsorbed aryl halides can be promoted by the photogenerated electrons on Pd NPs and the aromatic alcohols undergo dissociation and dehydrogenation, and finally can be oxidized by the captured photogenerated holes from CN-450 in the presence of a Br?nsted base. N defects, O doping, and improved crystallinity, controlled by changing the post-annealing temperature in molten salts, enhance the visible light absorption and improve charger carrier separation of the functionalized carbon nitride. The smaller size and high dispersity of Pd NPs give the higher surface area-to-volume ratio resulting in efficient adsorption and activation of reactant molecules on Pd NPs and allow for the effective interfacial interaction of CN-450 with Pd NPs for promoting electron transfer from CN-450 to Pd NPs. As a result, Pd/CN-450 displays a superior photocatalytic activity of the coupled reaction compared to Pd/g-C3N4 (Pd NP supported pristine g-C3N4). Moreover, the coupled reaction system has general applicability for various substrates and shows reusability.
- Jia, Qiaohui,Zhang, Sufen,Jia, Xiaoxia,Dong, Xiaoyang,Gao, Ziwei,Gu, Quan
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p. 5077 - 5089
(2019/10/05)
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- Facile One-Pot Transformation of Primary Alcohols into 3-Aryl- and 3-Alkyl-isoxazoles and -pyrazoles
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Various primary alcohols were smoothly transformed into 3-aryl- and 3-alkylisoxazoles in good yields in one pot by successive treatment with PhI(OAc) 2 in the presence of TEMPO, NH 2 OH, and then NCS, followed by reaction with alkynes in the presence of Et 3 N. Similarly, various primary alcohols were smoothly transformed into 3-aryl- and 3-alkylpyrazoles in good yields in one pot by successive treatment with PhI(OAc) 2 in the presence of TEMPO, PhNHNH 2, and then NCS and decyl methyl sulfide, followed by reaction with alkynes in the presence of Et 3 N. Thus, both 3-aryl- and 3-alkylisoxazoles, and 3-aryl- and 3-alkylpyrazoles could be prepared from readily available primary alcohols in one pot under transition-metal-free conditions.
- Kobayashi, Eiji,Togo, Hideo
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p. 3723 - 3735
(2019/09/30)
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- Aromatic aldehyde synthesis method
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The invention provides an aromatic aldehyde synthesis method. Aryl halide serves as a starting material, glyoxylic acid serves as a carbonyl source, proper palladium catalysts and phosphine-containingorganic ligands are used, and aromatic aldehyde serving as a target product is prepared by heating and sealing reaction. Raw materials of the synthesis method are easily obtained, operation is simple, the product is easily separated, total reaction rate is high, process cost is low, and the yield of the target product is easily adjusted. Therefore, the aromatic aldehyde synthesis method is beneficial to large-scale industrial production of the aromatic aldehyde.
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Paragraph 0078-0084
(2019/07/04)
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- Cyclopropenium-Activated DMSO for Swern-Type Oxidation
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Swern oxidation is widely used to convert alcohols into their corresponding carbonyl compounds. However, the conventional method with use of the volatile oxalyl chloride as an activator requires the reaction to be conducted below -60 °C. We discovered that 3,3-dichloro-1,2-diphenylcyclopropene (DDC) can be used as a new activator for Swern-type oxidations of alcohols, which can be conducted at -20 °C. This new protocol features mild and fast reactions with easy operation. Furthermore, the activator DDC is easy to handle, and diphenylcyclopropenone can be recovered quantitively. This new type of Swern oxidation shows a broad scope of substrates including benzylic, allylic, aliphatic, and biobased alcohols, and gives high yields of up to 93%.
- Guo, Tianfo,Gao, Yu,Li, Zhenjiang,Liu, Jingjing,Guo, Kai
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supporting information
p. 329 - 332
(2019/02/12)
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- Nanolayered cobalt-molybdenum sulphides (Co-Mo-S) catalyse borrowing hydrogen C-S bond formation reactions of thiols or H2S with alcohols
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Nanolayered cobalt-molybdenum sulphide (Co-Mo-S) materials have been established as excellent catalysts for C-S bond construction. These catalysts allow for the preparation of a broad range of thioethers in good to excellent yields from structurally diverse thiols and readily available primary as well as secondary alcohols. Chemoselectivity in the presence of sensitive groups such as double bonds, nitriles, carboxylic esters and halogens has been demonstrated. It is also shown that the reaction takes place through a hydrogen-autotransfer (borrowing hydrogen) mechanism that involves Co-Mo-S-mediated dehydrogenation and hydrogenation reactions. A novel catalytic protocol based on the thioetherification of alcohols with hydrogen sulphide (H2S) to furnish symmetrical thioethers has also been developed using these earth-abundant metal-based sulphide catalysts.
- Corma, Avelino,Sorribes, Iván
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p. 3130 - 3142
(2019/03/13)
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- Aldehydes as potential acylating reagents for oxidative esterification by inorganic ligand-supported iron catalysis
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The oxidative esterification of various aldehydes with alcohols could be achieved by a heterogeneous iron(iii) catalyst supported on a ring-like POM inorganic ligand under mild conditions, affording the corresponding esters, including several drug molecules and natural products, in high yields. ESI-MS and control experiments demonstrated that POM-FeV(O) was the active catalytic species and the plausible mechanism was presented. More importantly, the 6th run of the iron catalyst recycles shows only a slight decrease in the yield.
- Yu, Han,Wang, Jingjing,Wu, Zhikang,Zhao, Qixin,Dan, Demin,Han, Sheng,Tang, Jiangjiang,Wei, Yongge
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supporting information
p. 4550 - 4554
(2019/08/21)
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- A Deoximation Method for Deprotection of Ketones and Aldhydes Using a Graphene-Oxide-Based Co-catalysts System
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The deoximation of a wide range of ketoximes and aldoximes to their corresponding carbonyl compounds with high yields has been achieved using graphene oxide (GO) and sodium nitrite (NaNO2) as highly efficient catalysts and air as the green oxidant under mild conditions. The mechanism of deprotection and recycling use of catalyst were revealed in deep experiment. The carboxylic acid groups on the GO were essential for high catalytic activity. (Figure presented.).
- Tong, Qiaolin,Liu, Yang,Gao, Xuezhi,Fan, Zhanfang,Liu, Tianfu,Li, Bo,Su, Dangsheng,Wang, Qinghe,Cheng, Maosheng
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supporting information
p. 3137 - 3145
(2019/05/01)
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- Continuous-Flow Pd-Catalyzed Carbonylation of Aryl Chlorides with Carbon Monoxide at Elevated Temperature and Pressure
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The development of a continuous-flow protocol for a palladium-catalyzed methoxycarbonylation of (hetero)aryl chlorides using carbon monoxide gas and methanol is described. (Hetero)aryl chlorides are the least expensive of the aryl halides, but are underutilized in carbonylation reactions due to their very poor reactivity. The described protocol exploits intensified conditions at elevated temperature and pressure, which are readily accessed within a continuous-flow environment, to provide moderate to excellent product yields (11 examples) in a short 16 min residence time. The continuous-flow protocol enables the safe and potentially scalable carbonylation of aryl chlorides using CO gas.
- Mata, Alejandro,Hone, Christopher A.,Gutmann, Bernhard,Moens, Luc,Kappe, C. Oliver
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p. 997 - 1001
(2019/01/24)
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- Switchable Bifunctional Bistate Reusable ZnO-Cu for Selective Oxidation and Reduction Reaction
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Herein we disclosed the utilization of copper loaded zinc oxide (ZnO-Cu) for its stimuli (O2/light) responsive switchable performance between its reduced (S-1) and oxidized (S-2) state for two antagonistic reactions, namely oxidation of alkyl arenes/heteroarenes to aldehydes/ketones and reduction of nitro arenes/heteroarenes to corresponding amines. The two states of the catalyst showed its switchable performance as highly active and poorly active catalyst for oxidation and reduction, and both reactions could be turned "off" and "on" by changing the stimuli (light and O2/N2). The switching efficiency between the states and their relative reactivity were found to be consistent under variety of reaction conditions and remain unaltered irrespective of oxidation-reduction (or vice versa) sequence and substrates used in the reaction. The photo catalysts (S-1 and S-2) demonstrated good catalytic activity, multiple reusability, broad substrate scope, and reasonable functional group tolerance for both the reactions and probed its quality performance in a large-scale setup. The system was used in an assisted tandem catalysis setup for the synthesis of benzyl amines utilizing both oxidation and reduction reaction by stimuli responsive switching between the states of the catalyst.
- Sarmah, Kasturi,Mukhopadhyay, Subhamoy,Maji, Tarun K.,Pratihar, Sanjay
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p. 732 - 745
(2019/01/11)
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- Cobalt(ii)-catalyzed benzylic oxidations with potassium persulfate in TFA/TFAA
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A cobalt-catalyzed C(sp3)-H oxygenation reaction to furnish aldehyde was herein reported. This transformation demonstrated high chemo-selectivity, and tolerated various methylarenes bearing electron-withdrawing substituents. This reaction provided rapid access to diverse aldehydes form methylarenes. Notably, TFA/TFAA was used for the first time as a mixed solvent in cobalt-catalyzed oxygenation of benzylic methylenes.
- Li, Tianlei,Li, Jishun,Zhu, Zihao,Pan, Weidong,Wu, Song
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p. 20879 - 20883
(2019/07/12)
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- Nickel-Catalyzed Selective Reduction of Carboxylic Acids to Aldehydes
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The direct reduction of carboxylic acids to aldehydes is a fundamental transformation in organic synthesis. The combination of an air-stable Ni precatalyst, dimethyl dicarbonate as an activator, and silane reductant effects this reduction for a wide variety of substrates, including pharmaceutically relevant structures, in good yields and with no overreduction to alcohols. Moreover, this methodology is scalable, allows access to deuterated aldehydes, and is also compatible with one-pot utilization of the aldehyde products.
- Iosub, Andrei V.,Morav?ík, ?tefan,Wallentin, Carl-Johan,Bergman, Joakim
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supporting information
p. 7804 - 7808
(2019/10/14)
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- Five-membered azole-containing heterocyclic chalcone derivative, and preparation method and medical use thereof
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The invention discloses a five-membered azole-containing heterocyclic chalcone derivative, and a preparation method and a medical use thereof. The five-membered azole-containing heterocyclic chalconederivative is represented by general formula (I) shown in the description, and R1 in the is formula (I) is any one of formulas also shown in the description. A result of antitumor cell proliferation activity detection shows that the above compound has a certain inhibitory effect on the proliferation of lung cancer A549 and breast cancer MCF-7 cells, and can be used as an antitumor drug.
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Paragraph 0036; 0038-0040; 0047-0049
(2019/06/30)
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- NH3?H2O: The Simplest Nitrogen-Containing Ligand for Selective Aerobic Alcohol Oxidation to Aldehydes or Nitriles in Neat Water
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Aqueous ammonia (NH3?H2O) has been shown to serve as the simplest nitrogen-containing ligand to effectively promote copper-catalyzed selective alcohol oxidation under air in water. A series of alcohols with varying electronic and steric properties were selectively oxidized to aldehydes with up to 95 % yield. Notably, by increasing the amount of aqueous ammonia in neat water, the exclusive formation of aryl nitriles was also accomplished with good-to-excellent yields. Additionally, the catalytic system exhibits a high level of functional group tolerance with ?OH, ?NO2, esters, and heteroaryl groups all being amenable to the reaction conditions. This one-pot and green oxidation protocol provides an important synthetic route for the selective preparation of either aldehydes or nitriles from commercially available alcohols.
- Zhang, Guofu,Ma, Danting,Zhao, Yiyong,Zhang, Guihua,Mei, Guangyao,Lyu, Jinghui,Ding, Chengrong,Shan, Shang
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p. 885 - 889
(2018/12/10)
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