10535-17-8Relevant academic research and scientific papers
Cobalt Nanoparticles-Catalyzed Widely Applicable Successive C?C Bond Cleavage in Alcohols to Access Esters
Dai, Wen,Gao, Shuang,Li, Guosong,Luo, Huihui,Lv, Ying,Shang, Sensen,Wang, Lianyue
, p. 19268 - 19274 (2020)
Selective cleavage and functionalization of C?C bonds have important applications in organic synthesis and biomass utilization. However, functionalization of C?C bonds by controlled cleavage remains difficult and challenging because they are inert. Herein, we describe an unprecedented efficient protocol for the breaking of successive C?C bonds in alcohols to form esters with one or multiple carbon atoms less using heterogeneous cobalt nanoparticles as catalyst with dioxygen as the oxidant. A wide range of alcohols including inactive long-chain alkyl aryl alcohols undergo smoothly successive cleavage of adjacent ?(C?C)n? bonds to afford the corresponding esters. The catalyst was used for seven times without any decrease in activity. Characterization and control experiments disclose that cobalt nanoparticles are responsible for the successive cleavage of C?C bonds to achieve excellent catalytic activity, while the presence of Co-Nx has just the opposite effect. Preliminary mechanistic studies reveal that a tandem sequence reaction is involved in this process.
Highly Selective Oxidation and Depolymerization of α,γ-Diol-Protected Lignin
Lan, Wu,de Bueren, Jean Behaghel,Luterbacher, Jeremy S.
, p. 2649 - 2654 (2019)
Lignin oxidation offers a potential sustainable pathway to oxygenated aromatic molecules. However, current methods that use real lignin tend to have low selectivity and a yield that is limited by lignin degradation during its extraction. We developed stoichiometric and catalytic oxidation methods using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as oxidant/catalyst to selectively deprotect the acetal and oxidize the α-OH into a ketone. The oxidized lignin was then depolymerized using a formic acid/sodium formate system to produce aromatic monomers with a 36 mol % (in the case of stoichiometric oxidation) and 31 mol % (in the case of catalytic oxidation) yield (based on the original Klason lignin). The selectivity to a single product reached 80 % (syringyl propane dione, and 10–13 % to guaiacyl propane dione). These high yields of monomers and unprecedented selectivity are attributed to the preservation of the lignin structure by the acetal.
Br?nsted Acid Catalyzed Tandem Defunctionalization of Biorenewable Ferulic acid and Derivates into Bio-Catechol
Bal, Mathias,Bomon, Jeroen,Liao, Yuhe,Maes, Bert U. W.,Sels, Bert F.,Sergeyev, Sergey,Van Den Broeck, Elias,Van Speybroeck, Veronique
, p. 3063 - 3068 (2020/02/05)
An efficient conversion of biorenewable ferulic acid into bio-catechol has been developed. The transformation comprises two consecutive defunctionalizations of the substrate, that is, C?O (demethylation) and C?C (de-2-carboxyvinylation) bond cleavage, occurring in one step. The process only requires heating of ferulic acid with HCl (or H2SO4) as catalyst in pressurized hot water (250 °C, 50 bar N2). The versatility is shown on a variety of other (biorenewable) substrates yielding up to 84 % di- (catechol, resorcinol, hydroquinone) and trihydroxybenzenes (pyrogallol, hydroxyquinol), in most cases just requiring simple extraction as work-up.
Sequential Cleavage of Lignin Systems by Nitrogen Monoxide and Hydrazine
Altmann, Lisa-Marie,Heinrich, Markus R.,Hofmann, Dagmar,Hofmann, Laura Elena,Prusko, Lea
, (2020/03/27)
The cleavage of representative lignin systems has been achieved in a metal-free two-step sequence first employing nitrogen monoxide for oxidation followed by hydrazine for reductive C?O bond scission. In combining nitrogen monoxide and lignin, the newly developed valorization strategy shows the particular feature of starting from two waste materials, and it further exploits the attractive conditions of a Wolff-Kishner reduction for C?O bond cleavage for the first time. (Figure presented.).
Effective Synthesis of 3,4-Diaryl-isoxazole-5-carboxamides and their Antiproliferative Properties
Maksimenko, Anna S.,Kislyi, Victor P.,Chernysheva, Natalia B.,Strelenko, Yuri A.,Zubavichus, Yan V.,Khrustalev, Victor N.,Semenova, Marina N.,Semenov, Victor V.
, p. 4260 - 4270 (2019/07/12)
A simple scalable procedure for the synthesis of 3,4-diaryl-isoxazole-5-carboxamides 6 under mild conditions from readily available material was developed. The targeted compounds 6, structural analogues of heat shock protein inhibitors, were obtained by the rearrangement of intermediate 3,4-diaryl-5-carboxamido-isoxazoline N-oxides 5. In contrast to carboxamido-isoxazoline oxides 5, base-catalyzed recyclization of 3,4-diaryl-5-(ethoxycarbonyl)isoxazoline N-oxides 9c unexpectedly yielded 5-hydroxy-1,2-oxazin-6-ones 17c instead of ethyl 3,4-diaryl-isoxazole-5-carboxylates 10. Crystal and molecular structure of 4-(2,5-dimethoxy-3,4-methylenedioxyphenyl)-5-hydroxy-3-phenyl-6H-1,2-oxazin-6-one 17c was established by single-crystal X-ray diffraction study. In a phenotypic sea urchin embryo assay, carboxamide 6f showed moderate antimitotic antitubulin activity compared to 5-unsubstituted 3,4-diarylisoxazoles 15, which featured strong microtubule destabilizing effect.
Iridium-catalysed primary alcohol oxidation and hydrogen shuttling for the depolymerisation of lignin
Lancefield, Christopher S.,Teunissen, Lucas W.,Weckhuysen, Bert M.,Bruijnincx, Pieter C. A.
, p. 3214 - 3221 (2018/07/31)
Lignin is a potentially abundant renewable resource for the production of aromatic chemicals, however its selective depolymerisation is challenging. Here, we report a new catalytic system for the depolymerisation of lignin to novel, non-phenolic monoaromatic products based on the selective β-O-4 primary alcohol dehydrogenation with a Cp?Ir-bipyridonate catalyst complex under basic conditions. We show that this system is capable of promoting the depolymerisation of model compounds and isolated lignins via a sequence of selective primary alcohol dehydrogenation, retro-aldol (Cα-Cβ) bond cleavage and in situ stabilisation of the aldehyde products by transfer (de)hydrogenation to alcohols and carboxylic acids. This method was found to give good to excellent yields of cleavage products with both etherified and free-phenolic lignin model compounds and could be applied to real lignin to generate a range of novel non-phenolic monomers including diols and di-acids. We additionally show, by using the same catalyst in a convergent, one-pot procedure, that these products can be selectively channelled towards a single di-acid product, giving much simpler product mixtures as a result.
Transition-metal-free conversion of lignin model compounds to high-value aromatics: Scope and chemoselectivity
Lee, Tae Woo,Yang, Jung Woon
, p. 3761 - 3771 (2018/08/21)
An efficient and straightforward reaction protocol for the conversion of lignin model compounds was developed based on a simple system consisting of a base, oxygen, and a green solvent under mild conditions in the absence of metals. This protocol was successfully applied to the cleavage of both 'β-O-4' dimeric and trimeric compounds, and a controlled selective degradation was achieved depending on the bond type. The feasibility of this method to provide aromatic compounds in high yields from lignin by a sequential oxidative dehomologation reaction was clearly demonstrated.
Rational Design, Synthesis, and Biological Activity of N-(1,4-Benzoxazinone)Acetamide Derivatives as Potent Platelet Aggregation Inhibitors
Xiang, Yi,Wang, Xiu-Hua,Yang, Quan,Tan, Jia-Lian,Jang, Hee-Jae,Zuo, Hua,Shin, Dong-Soo
supporting information, p. 146 - 155 (2018/01/27)
Inappropriate thrombus formation within blood vessels is the leading cause of mortality in the industrialized world. Platelet aggregation activated by thrombin may have close relationship with thrombosis. Based on our studies on the pharmacophoric role of 1,4-benzoxazine-3(4H)-one for desirable platelet aggregation inhibitory activity, we identified N-(4-ethyl-3-oxo-3,4-dihydro-2H-benzo[b][1,4]oxazin-7-yl)-2-(4-methylpiperazin-1-yl)acetamide (BOAP-AM6) and N-(4-butyl-3-oxo-3,4-dihydro-2H-benzo[b][1,4]oxazin-7-yl)-2-(4-(4-fluorophenyl)piperazin-1-yl)acetamide (BOAP-AM21) as platelet aggregation inhibitors with an IC50 of 8.93 and 8.67 μM, respectively, as potent as the positive control aspirin. A combination of structure–activity relationships studies and molecular modeling revealed that the molecule BOAP-AM6 interacted with the amino acid residue TYR166 and ARG214 in the binding site of GPIIb/IIIa receptor through hydrogen bond and compound BOAP-AM21 acted on the amino acid residue ASN215 and ALA218, both through the same approach as the reported potent molecules 7a and 7b.
Synthesis and acaricidal activities of scopoletin phenolic ether derivatives: Qsar, molecular docking study and in silico Adme predictions
Luo, Jinxiang,Lai, Ting,Guo, Tao,Chen, Fei,Zhang, Linli,Ding, Wei,Zhang, Yongqiang
, (2018/05/04)
Thirty phenolic ether derivatives of scopoletin modified at the 7-hydroxy position were synthesized, and their structures were confirmed by IR,1H-NMR,13C-NMR, MS and elemental analysis. Preliminary acaricidal activities of these compounds against female adults of Tetranychus cinnabarinus (Boisduval) were evaluated using the slide-dip method. The results indicated that some of these compounds exhibit more pronounced acaricidal activity than scopoletin, especially compounds 32, 20, 28, 27 and 8 which exhibited about 8.41-, 7.32-, 7.23-, 6.76-, and 6.65-fold higher acaricidal potency. Compound 32 possessed the the most promising acaricidal activity and exhibited about 1.45-fold higher acaricidal potency against T. cinnabarinus than propargite. Statistically significant 2D-QSAR model supports the observed acaricidal activities and reveals that polarizability (HATS5p) was the most important parameter controlling bioactivity. 3D-QSAR (CoMFA: q2 = 0.802, r2 = 0.993; CoMSIA: q2 = 0.735, r2 = 0.965) results show that bulky substituents at R4, R1, R2 and R5 (C6, C3, C4, and C7) positions, electron positive groups at R5 (C7) position, hydrophobic groups at R1 (C3) and R2 (C4), H-bond donors groups at R1 (C3) and R4 (C6) will increase their acaricidal activity, which provide a good insight into the molecular features relevant to the acaricidal activity for further designing novel acaricidal agents. Molecular docking demonstrates that these selected derivatives display different bide modes with TcPMCA1 from lead compound and they interact with more key amino acid residues than scopoletin. In silico ADME properties of scopoletin and its phenolic ether derivatives were also analyzed and showed potential to develop as good acaricidal candidates.
1,3-dimethyl-7-substituted-quinazolinyl-2,4-diones, and synthesis method and application thereof
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Paragraph 0056; 0057; 0058; 0059; 0060; 0095; 0096, (2017/07/31)
The invention discloses 1,3-dimethyl-7-substituted-quinazolinyl-2,4-diones. The structural general formula of the compounds is disclosed in the specification, wherein R1 is hydrogen or ethyl; and R2 is a benzene ring, benzene ring derivative, heterocyclic ring or aliphatic hydrocarbon. Part of compounds have favorable inhibiting activities for Candida albicans, Aspergillus flavus, Torula histolytica and Aspergillus fumigatus. The compounds have obvious inhibiting activities for chitin synthetase, have favorable antibacterial effects, and can be used for preparing drugs for anti-pathogenic microorganisms.
