2357-33-7Relevant academic research and scientific papers
Asymmetric Retro-Claisen Reaction by Synergistic Chiral Primary Amine/Palladium Catalysis
Han, Yanfang,Zhang, Long,Luo, Sanzhong
supporting information, p. 7258 - 7261 (2019/10/02)
We described herein a chiral primary amine/palladium catalyzed asymmetric retro-Claisen reaction of β-diketones with salicylic carbonates. A series of chiral α-alkylated ketones and macrolides were obtained with good yields and excellent enantioselectivities upon a sequence of decarboxylative benzylation, retro-Claisen cleavage, and enamine protonation. This strategy features broad substrate scope, mild conditions, as well as high atom economy with salicylic carbonates as the o-quinone methide precursors.
Iridium-catalyzed highly efficient chemoselective reduction of aldehydes in water using formic acid as the hydrogen source
Yang, Zhanhui,Zhu, Zhongpeng,Luo, Renshi,Qiu, Xiang,Liu, Ji-Tian,Yang, Jing-Kui,Tang, Weiping
supporting information, p. 3296 - 3301 (2017/07/28)
A water-soluble highly efficient iridium catalyst is developed for the chemoselective reduction of aldehydes to alcohols in water. The reduction uses formic acid as the traceless reducing agent and water as a solvent. It can be carried out in air without the need for inert atmosphere protection. The products can be purified by simple extraction without any column chromatography. The catalyst loading can be as low as 0.005 mol% and the turn-over frequency (TOF) is as high as 73 800 mol mol-1 h-1. A wide variety of functional groups, such as electron-rich or deficient (hetero)arenes and alkenes, alkyloxy groups, halogens, phenols, ketones, esters, carboxylic acids, cyano, and nitro groups, are all well tolerated, indicating excellent chemoselectivity.
Water-promoted ortho-selective monohydroxymethylation of phenols in the NaBO2 system
Li, Hui-Jing,Wu, Ying-Ying,Wu, Qin-Xi,Wang, Rui,Dai, Chun-Yang,Shen, Zhi-Lun,Xie, Cheng-Long,Wu, Yan-Chao
, p. 3100 - 3107 (2014/05/06)
Water-promoted ortho-selective monohydroxymethylation of phenols in the NaBO2 system generates salicyl alcohols in 65-97% yields. A remarkable rate-enhancement by water was observed, and NaBO2 appeared to serve the dual role of a suitable base and an efficient chelating reagent. This protocol possesses many advantages such as short reaction times, expanded substrate scope, and high mono- and regio-selectivities. The experimental results were explained by the calculations based on local ionisation energy minima, leading to a possible reaction mechanism.
Substituent effects on oxidation-induced formation of quinone methides from arylboronic ester precursors
Cao, Sheng,Christiansen, Robin,Peng, Xiaohua
, p. 9050 - 9058 (2013/07/26)
A series of arylboronic esters containing different aromatic substituents and various benzylic leaving groups (Br or N+Me3Br -) have been synthesized. The substituent effects on their reactivity with H2O2 and formation of quinone methide (QM) have been investigated. NMR spectroscopy and ethyl vinyl ether (EVE) trapping experiments were used to determine the reaction mechanism and QM formation, respectively. QMs were not generated during oxidative cleavage of the boronic esters but by subsequent transformation of the phenol products under physiological conditions. The oxidative deboronation is facilitated by electron-withdrawing substituents, such as aromatic F, NO2, or benzylic N+Me 3Br-, whereas electron-donating substituents or a better leaving group favor QM generation. Compounds containing an aromatic CH 3 or OMe group, or a good leaving group (Br), efficiently generate QMs under physiological conditions. Finally, a quantitative relationship between the structure and activity has been established for the arylboronic esters by using a Hammett plot. The reactivity of the arylboronic acids/esters and the inhibition or facilitation of QM formation can now be predictably adjusted. This adjustment is important as some applications may benefit and others may be limited by QM generation. Tunable quinone methide formation: Aromatic substituents and the benzylic leaving group strongly affect the H 2O2-induced formation of quinone methides (QMs) from arylboronic esters (see scheme). The reactivity of arylboronic esters can be predictably adjusted by varying substituents. Copyright
Fluorinated benzofuran derivatives for PET imaging of β-amyloid plaques in alzheimer's disease brains
Cheng, Yan,Ono, Masahiro,Kimura, Hiroyuki,Kagawa, Shinya,Nishii, Ryuichi,Kawashima, Hidekazu,Saji, Hideo
scheme or table, p. 321 - 325 (2010/12/18)
A series of fluorinated benzofuran derivatives as potential tracers for positron emission tomography (PET) targeting β-amyloid plaques in the brains of patients with Alzheimer's disease (AD) were synthesized and evaluated. The derivatives were produced using an intramolecular Wittig reaction. In experiments in vitro, all displayed high affinity for Aβ(1-42) aggregates with Ki values in the nanomolar range. Radiofluorinated 17, [ 18F]17, in particular labeled β-amyloid plaques in sections of Tg2576 mouse brain and displayed high uptake (5.66% ID/g) at 10 min postinjection, sufficient for PET imaging. In addition, in vivo β-amyloid plaque labeling can be clearly demonstrated with [18F]17 in Tg2576 mice. In conclusion, [18F]17 may be useful for detecting β-amyloid plaques in patients with AD.
Dicarboxylic Acid Derivatives and their Use
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Page/Page column 30, (2010/03/02)
The present application relates to novel dicarboxylic acid derivatives, process for their preparation, their use for the treatment and/or prophylaxis of diseases, and their use for producing medicaments for the treatment and/or prophylaxis of diseases, es
SUBSTITUTED DIBENZOIC ACID DERIVATIVES AND USE THEREOF
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Page/Page column 12, (2010/07/08)
The invention relates to novel substituted dibenzoic acid derivatives of formula (I), wherein A represents a group of formula (II) or (III), to methods for producing the same, and to their use in the treatment and/or prophylaxis of diseases. The invention
LACTAM-SUBSTITUTED DICARBOXYLIC ACIDS AND USE THEREOF
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Page/Page column 13-14, (2010/08/08)
The present application relates to novel lactam-substituted dicarboxylic acid derivatives, processes for their preparation, their use for the treatment and/or prophylaxis of diseases, and their use for producing medicaments for the treatment and/or prophylaxis of diseases, especially for the treatment and/or prevention of cardiovascular disorders.
Heterocyclic compounds with carboxyl isostere groups and their use for the treatment of cardiovascular diseases
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Page/Page column 41-42, (2009/09/25)
The present application relates to novel heterocyclic compounds, processes for their preparation, their use for the treatment and/or prophylaxis of diseases, and their use for producing medicaments for the treatment and/or prophylaxis of diseases, especia
Efficient Procedure for Preparing Salicyl Alcohols
Belyanin,Filimonov,Krasnov
, p. 103 - 105 (2007/10/03)
A new convenient procedure was developed for selective ortho-hydroxymethylation of phenols by reaction of paraformaldehyde with a mixture of phenol and orthoboric acid. The method is general for phenols containing no strong electron-withdrawing substituents; it allows preparation of o-hydroxybenzyl alcohols of high purity in a high yield.
