5556-86-5Relevant articles and documents
Monodentate Transient Directing Group Enabled Pd-Catalyzed Ortho-C-H Methoxylation and Chlorination of Benzaldehydes
Li, Feng,Zhou, Yirong,Yang, Heng,Wang, Ziqi,Yu, Qinqin,Zhang, Fang-Lin
supporting information, p. 3692 - 3695 (2019/05/24)
We report Pd-catalyzed ortho-C-H methoxylation and chlorination of benzaldehydes by employing monodentate transient directing groups (TDGs) as an alternative strategy to bidentate TDGs. More importantly, a single crystal of benzaldehyde imine ortho-cyclopalladium intermediate was successfully obtained, and its structure was unambiguously determined by X-ray diffraction, which clearly showed that it was a binuclear palladium species bridged by a pyridone ligand. The utility of this approach was further demonstrated through the synthesis of key intermediates of natural products and drugs.
Polygala tenuifolia-Acori tatarinowii herbal pair as an inspiration for substituted cinnamic α-asaronol esters: Design, synthesis, anticonvulsant activity, and inhibition of lactate dehydrogenase study
Bai, Yajun,He, Xirui,Bai, Yujun,Sun, Ying,Zhao, Zefeng,Chen, Xufei,Li, Bin,Xie, Jing,Li, Yang,Jia, Pu,Meng, Xue,Zhao, Ye,Ding, Yanrui,Xiao, Chaoni,Wang, Shixiang,Yu, Jie,Liao, Sha,Zhang, Yajun,Zhu, Zhiling,Zhang, Qiang,Zhao, Yuhui,Qin, Fanggang,Zhang, Yi,Wei, Xiaoyang,Zeng, Min,Liang, Jing,Cuan, Ye,Shan, Guangzhi,Fan, Tai-Ping,Wu, Biao,Zheng, Xiaohui
, (2019/09/18)
Inspired by the traditional Chinese herbal pair of Polygala tenuifolia-Acori Tatarinowii for treating epilepsy, 33 novel substituted cinnamic α-asaronol esters and analogues were designed by Combination of Traditional Chinese Medicine Molecular Chemistry (CTCMMC) strategy, synthesized and tested systematically not only for anticonvulsant activity in three mouse models but also for LDH inhibitory activity. Thereinto, 68–70 and 75 displayed excellent and broad spectra of anticonvulsant activities with modest ability in preventing neuropathic pain, as well as low neurotoxicity. The protective indices of these four compounds compared favorably with stiripentol, lacosamide, carbamazepine and valproic acid. 68–70 exhibited good LDH1 and LDH5 inhibitory activities with noncompetitive inhibition type, and were more potent than stiripentol. Notably, 70, as a representative agent, was also shown as a moderately positive allosteric modulator at human α1β2γ2 GABAA receptors (EC50 46.3 ± 7.3 μM). Thus, 68–70 were promising candidates for developing into anti-epileptic drugs, especially for treatment of refractory epilepsies such as Dravet syndrome.
Synthesis of 1,2,4-trimethoxybenzene and its selective functionalization at C-3 by directed metalation
Alves, Ana P. L.,Junior, Jose Augusto B. C.,Slana, Glaucia B. A.,Cardoso, Jari N.,Wang, Qiang,Lopes, Rosangela S. C.,Lopes, Claudio C.
experimental part, p. 3693 - 3709 (2009/12/06)
A new and efficient strategy was developed for the preparation of 1,2,4-trimethoxybenzene (3, a powerful attractant of Euglossini bees) and its C-3 derivatives (7a-j), from vanillin (2) in 56% overall yield.
Discrimination and identification of the six aromatic positional isomers of trimethoxyamphetamine (TMA) by gas chromatography-mass spectrometry (GC-MS)
Zaitsu, Kei,Katagi, Munehiro,Kamata, Hiroe,Kamata, Tooru,Shima, Noriaki,Miki, Akihiro,Iwamura, Tatsunori,Tsuchihashi, Hitoshi
, p. 528 - 534 (2008/09/20)
A reliable and accurate GC-MS method was developed that allows both mass spectrometric and chromatographic discrimination of the six aromatic positional isomers of trimethoxyamphetamine (TMA). Regardless of the trifluoroacetyl (TFA) derivatization, chromatographic separation of all the investigated isomers was achieved by using DB-5ms capillary columns (30 m x 0.32 mm i.d.), with run times less than 15 min. However, the mass spectra of the nonderivatized TMAs, except 2,4,6-trimethoxyamphetmine (TMA-6), showed insufficient difference for unambiguous discrimination. On the other hand, the mass spectra of the TFA derivatives of the six isomers exhibited fragments with significant intensity differences, which allowed the unequivocal identification of all the aromatic positional isomers investigated in the present study. This GC-MS technique in combination with TFA derivatization, therefore, is a powerful method to discriminate these isomers, especially useful to distinguish the currently controlled 3,4,5-trimethoxyamphetmine (TMA-1) and 2,4,5-trimethoxyamphetmine (TMA-2) from other uncontrolled TMAs. Copyright
Total syntheses of new proansamitocin derivatives by ring-closing metathesis
Meyer, Axel,Kirschning, Andreas
, p. 1264 - 1268 (2008/02/11)
The enantioselective synthesis of two new proansamitocin derivatives is described. Macrocyclization is achieved by ring-closing metathesis of appropriate alkene and diene precursors. Georg Thieme Verlag Stuttgart.
Design, synthesis, and structure - Activity relationships for chimeric inhibitors of Hsp90
Shen, Gang,Wang, Mingwen,Welch, Timothy R.,Blagg, Brian S. J.
, p. 7618 - 7631 (2007/10/03)
(Chemical Equation Presented) Inhibition of the 90 kDa heat shock protein (Hsp90) family of molecular chaperones represents a promising new chemotherapeutic approach toward the treatment of several cancers. Previous studies have demonstrated that the natural products, radicicol and geldanamycin, are potent inhibitors of the Hsp90 N-terminal ATP binding site. The cocrystal structures of these molecules bound to Hsp90 have been determined, and through molecular modeling and superimposition of these ligands, hybrids of radicicol and geldanamycin have been designed. A series of macrocylic chimeras of radicicol and geldanamycin and the corresponding seco-agents have been prepared and evaluated for both antiproliferative activity and their ability to induce Hsp90-dependent client protein degradation.
Total synthesis of (+)-geldanamycin and (-)-o-quinogeldanamycin: Asymmetric glycolate aldol reactions and biological evaluation
Andrus, Merritt B.,Meredith, Erik L.,Hicken, Erik J.,Simmons, Bryon L.,Glancey, Russell R.,Ma, Wei
, p. 8162 - 8169 (2007/10/03)
The total synthesis of (+)-geldanamycin (GA), following a linear route, has been completed using a demethylative quinone-forming reaction as the last step. Key steps include the use of two new asymmetric boron glycolate aldol reactions. To set the anti-C11,12 hydroxymethoxy functionality, (S,S)-5,6-bis-4-methoxyphenyldioxanone 8 was used. Methylglycolate derived from norephedrine 5 set the C6,7 methoxyurethane stereochemistry. The quinone formation step using nitric acid gave the non-natural o-quino-GA product 55 10: 1 over geldanamycin. Other known oxidants gave an unusual azaquinone product 49. o-Quino-GA 55 binds Hsp90 with good affinity but is less cytotoxic compared to GA.
Total synthesis of (+)-geldanamycin and (-)-o-quinogeldanamycin with use of asymmetric anti- and syn-glycolate aldol reactions
Andrus, Merritt B.,Meredith, Erik L.,Simmons, Bryon L.,Sekhar, B. B. V. Soma,Hicken, Erik J.
, p. 3549 - 3552 (2007/10/03)
(matrix presented) Geldanamycin (GA), an antitumor Hsp90 inhibitor, was made for the first time by using an oxidative demethylation reaction as the final step. A biaryldioxanone auxiliary set the anti C11-12 hydroxy-methoxy functionality and a methylglycolate auxiliary based on norephedrine was used for the syn C6-7 methoxy-urethane. p-Quinone-forming oxidants, CAN and AgO, produced an unusual aza-quinone product. Nitric acid gave GA from a trimethoxy precursor in 55% yield as a 1:10 mixture with nonnatural o-quino-GA.
Synthesis of the left-hand portion of geldanamycin using an anti glycolate aldol reaction.
Andrus,Meredith,Sekhar
, p. 259 - 262 (2007/10/03)
[figure: see text] A synthesis of the left-hand portion of the ansamycin antitumor natural product geldanamycin is reported. An advanced intermediate incorporates the methoxyquinone precursor as a pentasubstituted benzene with a 10-carbon chain that contains 4 of the 6 stereocenters. The key reaction is a novel anti glycolate aldol reaction with a new diaryl-4-oxapyrone used to generate the C-11, C-12 hydroxy, methoxy functionality.
