70877-75-7Relevant academic research and scientific papers
A Catalyst-Controlled Enantiodivergent Bromolactonization
Chan, Yuk-Cheung,Lam, Ying-Pong,Tse, Ying-Lung Steve,Wang, Xinyan,Wong, Jonathan,Yeung, Ying-Yeung
supporting information, p. 12745 - 12754 (2021/08/30)
A catalyst-controlled enantiodivergent bromolactonization of olefinic acids has been developed. Quinine-derived amino-amides bearing the same chiral core but different achiral aryl substituents were used as the catalysts. Switching the methoxy substituent in the aryl amide system from meta- to ortho-position results in a complete switch in asymmetric induction to afford the desired lactone in good enantioselectivity and yield. Mechanistic studies, including chemical experiments and density functional theory calculations, reveal that the differences in steric and electronic effects of the catalyst substituent alter the reaction mechanism.
Early and Late Steps of Quinine Biosynthesis
Trenti, Francesco,Yamamoto, Kotaro,Hong, Benke,Paetz, Christian,Nakamura, Yoko,O'Connor, Sarah E.
supporting information, p. 1793 - 1797 (2021/04/05)
The enzymatic basis for quinine 1 biosynthesis was investigated. Transcriptomic data from the producing plant led to the discovery of three enzymes involved in the early and late steps of the pathway. A medium-chain alcohol dehydrogenase (CpDCS) and an esterase (CpDCE) yielded the biosynthetic intermediate dihydrocorynantheal 2 from strictosidine aglycone 3. Additionally, the discovery of an O-methyltransferase specific for 6′-hydroxycinchoninone 4 suggested the final step order to be cinchoninone 16/17 hydroxylation, methylation, and keto-reduction.
Enantioselective 1,6-Conjugate Addition of Dialkyl α-Diazo Methylphosphonate to para-Quinone Methides
Chen, Yuan,Yu, Rui,Wang, Min,Huang, Yanmin,Peng, Yungui
supporting information, p. 4856 - 4861 (2021/09/06)
An asymmetric 1,6-conjugate addition reaction of dialkyl diazomethylphosphonates to para-quinone methides promoted by phase-transfer catalysis has been developed. A series of chiral diarylmethylated diazomethylphosphonates were accessed with up to 85% yields and 99% ee enantioselectivities. The resulting products were further transformed into bioactive compounds, namely, a chiral dihydrocinnoline phosphonate and a chiral α-aminophosphonate, bearing diarylmethine stereogenic centers. (Figure presented.).
Enantioselective γ-Alkylation of α,β-Unsaturated Aldehydes Using New Cinchona-Based Primary Amine Catalyst
Huang, Yong-Shuang,Song, Shuang-Gui,Ren, Lei,Li, You-Gui,Wu, Xiang
supporting information, p. 6838 - 6841 (2019/11/11)
New cinchona-based primary amine catalysts were prepared and screened as organocatalysts for the γ-alkylation of α,β-unsaturated aldehydes with bis(4-dimethylaminophenyl)methanol. Catalyst C3 containing acetic acid group yielded γ-alkylated products in good yields (up to 94 %) with up to 90 % ee. This new primary aminocatalyst provide new opportunities to explore novel asymmetric transformations.
Organocatalytic Nitroaldol Reaction Associated with Deuterium-Labeling
Yamada, Tsuyoshi,Kuwata, Marina,Takakura, Ryoya,Monguchi, Yasunari,Sajiki, Hironao,Sawama, Yoshinari
supporting information, p. 637 - 641 (2017/12/13)
A deuterium-labeling reaction of nitroalkanes in deuterium oxide and the subsequent nitroaldol reaction have been accomplished under basic and organocatalytic conditions to provide the deuterium-labeled β-nitroalcohols in high yields and high deuterium contents. β-Deuterated β-nitroalcohols could be smoothly obtained from the reaction of nitroalkanes and various electrophiles using the easily-removal basic resin WA30. Furthermore, the asymmetric nitroaldol reaction using nitromethane and α-keto esters as electrophiles in the presence of a quinine-derived organocatalyst in deuterium oxide could provide the desired β-deuterated nitroalcohol derivatives with high enantioselectivities. (Figure presented.).
DERIVATIVES OF QUINOLINE AS INHIBITORS OF DYRK1A AND/OR DYRK1B KINASES
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Paragraph 0503-0504, (2018/07/15)
The present invention relates to the compound of formula (I) and salts, stereoisomers, tautomers or N-oxides thereof. The present invention is further concerned with the use of such a compound or salt, stereoisomer, tautomer or N-oxide thereof as medicament and a pharmaceutical composition comprising said compound.
ENANTIOENRICHED VIRIDICATUMTOXIN B ANALOGS
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Page/Page column 67; 68; 71, (2017/11/10)
In one aspect, the present disclosure provides derivatives of viridicatumtoxin of the formula wherein the variables are as defined herein. Also provided herein are compositions and methods of treating a bacterial infection, a viral infection, or in the treatment of cancer. The present disclosure also provides methods of synthesizing enantiopure viridicatumtoxin and other anthrone compounds.
Asymmetric Alkylation of Anthrones, Enantioselective Total Synthesis of (?)- and (+)-Viridicatumtoxins B and Analogues Thereof: Absolute Configuration and Potent Antibacterial Agents
Nicolaou,Liu, Guodu,Beabout, Kathryn,McCurry, Megan D.,Shamoo, Yousif
supporting information, p. 3736 - 3746 (2017/03/20)
A phase transfer catalyzed asymmetric alkylation of anthrones with cyclic allylic bromides using quinidine- or quinine-derived catalysts is described. Utilizing mild basic conditions and as low as 0.5 mol % catalyst loading, and achieving up to >99:1 dr selectivity, this asymmetric reaction was successfully applied to produce enantioselectively (?)- and (+)-viridicatumtoxins B, and thus allowed assignment of the absolute configuration of this naturally occurring antibiotic. While the developed asymmetric synthesis of C10 substituted anthrones is anticipated to find wider applications in organic synthesis, its immediate application to the construction of a variety of designed enantiopure analogues of viridicatumtoxin B led to the discovery of highly potent, yet simpler analogues of the molecule. These studies are expected to facilitate drug discovery and development efforts toward new antibacterial agents.
Enantioselective Spirocyclopropanation of para-Quinone Methides Using Ammonium Ylides
Roiser, Lukas,Waser, Mario
supporting information, p. 2338 - 2341 (2017/05/12)
The use of Cinchona alkaloid-based chiral ammonium ylides allows for the first highly enantioselective and broadly applicable spirocyclopropanation reactions of para-quinone methides. This strategy provides a straightforward protocol toward the chiral spiro[2.5]octa-4,7-dien-6-one skeleton, which is a frequently found structural motif in important biologically active molecules.
Development of C-6′-modified quinine-derived phase-transfer catalysts and their application in the enantioselective α-hydroxylation of β-dicarbonyl compounds
Qing, Hai,Wang, Yakun,Zheng, Zehao,Chen, Shuai,Meng, Qingwei
, p. 834 - 842 (2016/09/02)
We have developed C-6′-modified quinine quaternary ammonium salts as phase transfer catalysts for α-hydroxylation of β-dicarbonyl compounds. The quinine quaternary ammonium salts, which was modified at C-6′ and the N atom, had good activity for α-hydroxylation of β-dicarbonyl compounds. By using 5?mol?% of 6-hydroxyl-N-(4′-fluoro-2′-trifluoromethyl)quinine quaternary ammonium salt as the organocatalyst, cumene hydroperoxide as the oxidant, toluene as the solvent, and 50% K2HPO4as the aqueous alkali at room temperature, the yield and enantioselectivity of the α-hydroxylation of β-keto esters were 95% and 88%, respectively. This catalytic system was also applicable for β-keto amides (92% yield and 76% ee).
