2426-87-1Relevant articles and documents
Concise and Efficient Synthesis of [6]-Paradol
Shi, Xiang,Xia, Tiantian,McKamey, Brooke E.,Wu, Xian,Sun, Yue,Zhou, Weifeng,Zhang, Guangyan
, p. 1360 - 1365 (2021)
An efficient synthesis of [6]-paradol (1) has been performed in four steps with a 72.0% overall yield. The present method highlights commercially available materials, convenient isolation with multiple crystallization without involving column chromatography, and a high-purity product (more than 99.2%), and it is amenable to large-scale synthesis.
Synthesis of enantiomerically pure lignin dimer models for catalytic selectivity studies
Njiojob, Costyl N.,Rhinehart, Jennifer L.,Bozell, Joseph J.,Long, Brian K.
, p. 1771 - 1780 (2015)
A series of highly enantioselective transformations, such as the Sharpless asymmetric epoxidation and Jacobsen hydrolytic kinetic resolution, were utilized to achieve the complete stereoselective synthesis of β-O-4 lignin dimer models containing the S, G, and H subunits with excellent ee (>99%) and moderate to high yields. This unprecedented synthetic method can be exploited for enzymatic, microbial, and chemical investigations into lignins degradation and depolymerization as related to its stereochemical constitution. Preliminary degradation studies using enantiopure Co(salen) catalysts are also reported.
Identification and quantification of lignin monomers and oligomers from reductive catalytic fractionation of pine wood with GC × GC – FID/MS
Dao Thi, Hang,Van Aelst, Korneel,Van den Bosch, Sander,Katahira, Rui,Beckham, Gregg T.,Sels, Bert F.,Van Geem, Kevin M.
supporting information, p. 191 - 206 (2022/01/19)
Thorough lignin characterization is vital to understand the physicochemical properties of lignin and to evaluate lignocellulose biorefinery processes. In this study, an in-depth characterization of lignin oil, obtained from reductive catalytic fractionati
Catalytic δ-hydroxyalkynone rearrangement in the stereoselective total synthesis of centrolobine, engelheptanoxides A and C and analogues
Ahmad, Mohammad N.,Chopra, Sidharth,Fernandes, Rodney A.,Kumar, Praveen
, (2021/08/13)
A catalytic stereoselective total synthesis of centrolobine and engelheptanoxides A and C has been completed via a metal-free catalytic δ-hydroxyalkynone rearrangement to 2,3-dihydro-4H-pyran-4-one and diastereoselective hydrogenation to the all syn-2,4,6-trisubstituted pyran strategy. The onliest required chirality was introduced by Jacobsen kinetic resolution, which further directed the diastereoselective hydrogenation. A first stereoselective synthesis of engelheptanoxide A is also accomplished. The analogues and derivatives of centrolobine and engelheptanoxides prepared were evaluated for antitubercular activity against M. tuberculosis H37Rv ATCC 27294.
An Expeditious Modular Hybrid Strategy for the Diversity-Oriented Synthesis of Lamellarins/Azalamellarins with Anticancer Cytotoxicity
Klumthong, Kanawut,Chalermsub, Papornchanok,Sopha, Pattarawut,Ruchirawat, Somsak,Ploypradith, Poonsakdi
, p. 14883 - 14902 (2021/09/13)
A modular hybrid strategy has been developed for the diversity-oriented synthesis of lamellarins/azalamellarins. The common pentacyclic pyrrolodihydroisoquinoline lactone/lactam core was formed via the Michael addition/ring closure (Mi-RC) and the copper(I) thiophene-2-carboxylate (CuTC)-catalyzed C-O/C-N Ullmann coupling. Subsequent direct functionalization at C1, DDQ-mediated C5C6 oxidation, and global deprotection of all benzyl-type O- and N-protecting groups furnished the desired lamellarins/azalamellarins. The late-stage functionalization at C1 provided a handle to accommodate a wider scope of functional groups as they need to tolerate only the DDQ oxidation and global deprotection. Moreover, with the C1-H pyrrole as the late-stage common intermediate, it was also possible to divergently exploit not only its nucleophilic nature to react with some electrophilic species but also some transition-metal-catalyzed cross-coupling reactions (via the intermediacy of the C1-iodopyrrole) to incorporate diversity at this position. Overall, this strategy simplifies the preparation of lamellarins/azalamellarins; including the Mi-RC, these C1-structurally diverse analogues could be prepared efficiently in 6-7 steps from the easily accessed 1-acetoxymethyldihydroisoquinoline and β-nitrocinnamate. Some selected azalamellarins were evaluated for their inhibitory effect against HeLa cervical cancer cells. An acute induction of intrinsic apoptosis was detected and may lead to growth suppression of or cytotoxicity against cancer cells.
Ferulic acid amide derivatives with varying inhibition of amyloid-β oligomerization and fibrillization
Kolaj, Igri,Wang, Yanfei,Ye, Kailin,Meek, Autumn,Liyanage, S. Imindu,Santos, Clarissa,Weaver, Donald F.
supporting information, (2021/07/07)
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized, in part, by the misfolding, oligomerization and fibrillization of amyloid-β (Aβ). Evidence suggests that the mechanisms underpinning Aβ oligomerization and subsequent fibrillization are distinct, and may therefore require equally distinct therapeutic approaches. Prior studies have suggested that amide derivatives of ferulic acid, a natural polyphenol, may combat multiple AD pathologies, though its impact on Aβ aggregation is controversial. We designed and synthesized a systematic library of amide derivatives of ferulic acid and evaluated their anti-oligomeric and anti-fibrillary capacities independently. Azetidine tethered, triphenyl derivatives were the most potent anti-oligomeric agents (compound 2i: IC50 = 1.8 μM ± 0.73 μM); notably these were only modest anti-fibrillary agents (20.57% inhibition of fibrillization), and exemplify the poor correlation between anti-oligomeric/fibrillary activities. These data were subsequently codified in an in silico QSAR model, which yielded a strong predictive model of anti-Aβ oligomeric activity (κ = 0.919 for test set; κ = 0.737 for validation set).
Chromium-Salen Complex/Nitroxyl Radical Cooperative Catalysis: A Combination for Aerobic Intramolecular Dearomative Coupling of Phenols
Nagasawa, Shota,Fujiki, Shogo,Sasano, Yusuke,Iwabuchi, Yoshiharu
, p. 6952 - 6968 (2021/05/29)
We describe an aerobic intramolecular dearomative coupling reaction of tethered phenols using a catalytic system consisting of a chromium-salen (Cr-salen) complex combined with a nitroxyl radical. This novel catalytic system enables formation of various spirocyclic dienone products including those unable to be accessed by previously reported methods efficiently under mild reaction conditions.
Synthesis and antitumor activity of novel pyridoxine-based structural analogs of saccharumoside-B
Pugachev, Mikhail V.,Agafonova, Maria N.,Bastrikova, Oksana A.,Gnezdilov, Oleg I.,Nikishova, Tatyana V.,Balakin, Konstantin V.,Shtyrlin, Yurii G.
, p. 1139 - 1150 (2021/03/31)
A series of 11 new pyridoxine-based structural analogs of saccharumoside-B were obtained using original synthetic approach. Antitumor activity of these compounds against nine human tumor cell lines (MCF-7, MDA-MB-231, A-498, SNB-19, M-14, NCI-H322M, HCT-115, HCT-116, and PC-3) was studied, and cytotoxic activity to three normal (HEK-293, Chang Liver, and MSC) cell lines was evaluated. Among the synthesized compounds, 12d, 12e, 13b, 13d, 13e, and 14 exhibited the highest antitumor activity, comparable to that of camptothecin and doxorubicin, but with significantly increased selectivity toward tumor cells. [Figure not available: see fulltext.]
PhIO-Mediated oxidative dethioacetalization/dethioketalization under water-free conditions
Du, Yunfei,Ouyang, Yaxin,Wang, Xi,Wang, Xiaofan,Yu, Zhenyang,Zhao, Bingyue,Zhao, Kang
, p. 48 - 65 (2021/06/16)
Treatment of thioacetals and thioketals with iodosobenzene in anhydrous DCM conveniently afforded the corresponding carbonyl compounds in high yields under water-free conditions. The mechanistic studies indicate that this dethioacetalization/dethioketalization process does not need water and the oxygen of the carbonyl products comes from the hypervalent iodine reagent.
Oxidation of alcohols to aldehydes with bromoisobutyrate and dimethyl sulfoxide
Wu, Fei-Yue,Chen, Xiao-Hui,Zhou, Hai-Mei,Li, Jia-Qin,Cui, Hai-Lei
supporting information, (2021/09/29)
We have developed an efficient oxidation of primary alcohols to aldehydes with ethyl bromoisobutyrate and dimethyl sulfoxide. Diaryl ketone can also be prepared under this reaction system.
