2419-38-7Relevant articles and documents
Absolute configuration of α-phthalimido carboxylic acid derivatives from circular dichroism spectra
Skowronek,Gawronski
, p. 4585 - 4590 (1999)
It is demonstrated that the Cotton effects due to the 220 nm phthalimide π-π* transition observed for a series of derivatives of α- phthalimidocarboxylic acids unequivocally reflect the amino acid absolute configuration. This method is based on the exciton coupling of the allowed transitions of the phthalimide and the carboxylic acid derivative chromophores. (C) 1999 Elsevier Science Ltd.
Enantiomerically Pure [2.2]Paracyclophane-4-thiol: A Planar Chiral Sulfur-Based Building Block Readily Available by Resolution with an Amino Acid Chiral Auxiliary
Vincent, Adrien,Deschamps, Damien,Martzel, Thomas,Lohier, Jean-Fran?ois,Richards, Christopher J.,Gaumont, Annie-Claude,Perrio, Stéphane
, p. 3961 - 3966 (2016)
Acyl chloride of N-phthaloyl-(S)-isoleucine is an efficient chiral auxiliary for the resolution of (±)-[2.2]paracyclophane-4-thiol. A preparative protocol, based on the conversion into diastereoisomeric thiolesters and separation by two fractional crystallizations and column chromatography, was developed. Deprotection with LiAlH4 allowed isolation of the individual thiol enantiomers in good yield (～40%) and high enantiomeric purity (ee >93%). The absolute configurations were determined by comparison of the optical rotation value of the products with literature data and were confirmed by X-ray crystallography.
Stereocontrolled synthesis of (S)-γ-fluoroleucine
Padmakshan, Dharshana,Bennett, Simon A.,Otting, Gottfried,Easton, Christopher J.
, p. 1083 - 1084 (2007)
Starting with (S)-leucine, the corresponding γ-fluoride 8 has been prepared in a stereocontrolled fashion, by exploiting methods for the direct side-chain bromination of amino acid derivatives and silven(I) fluoride as the fluorinating reagent. Georg Thieme Verlag Stuttgart.
Chiral sensors for determining the absolute configurations of α-amino acid derivatives
Chen, Zhongxiang,Fan, Hongjun,Yang, Shiwei,Bian, Guangling,Song, Ling
, p. 6933 - 6939 (2018)
A simple strategy for configurational assignments of alpha-amino acids has been developed by comparison of the proton NMR chemical shift values of the alpha hydrogens of N-phthaloyl protected alpha-amino acids in the presence of (R)-CSA 1 and (S)-CSA 1, respectively. Highly resolved NMR spectra can be obtained directly on the mixed solution of the chiral solvating agents with N-phthaloyl protected alpha-amino acids in NMR tubes, giving well distinguishable proton signals without interference which dramatically improve the accuracy of assignment and hasten the assigning procedure. The strategy is widely applicable for varied natural and non-natural amino acids.
Structure-Activity Relationships for the Marine Natural Product Sintokamides: Androgen Receptor N-Terminus Antagonists of Interest for Treatment of Metastatic Castration-Resistant Prostate Cancer
Yan, Luping,Banuelos, Carmen A.,Mawji, Nasrin R.,Patrick, Brian O.,Sadar, Marianne D.,Andersen, Raymond J.
, p. 797 - 813 (2020/11/13)
Synthetic analogues of the marine natural product sintokamides have been prepared in order to investigate the structure-activity relationships for the androgen receptor N-terminal domain (AR NTD) antagonist activity of the sintokamide scaffold. An in vitro LNCaP cell-based transcriptional activity assay with an androgen-driven luciferase (Luc) reporter was used to monitor the potency of analogues. The data have shown that the chlorine atoms on the leucine side chains are essential for potent activity. Analogues missing the nonchlorinated methyl groups of the leucine side chains (C-1 and C-17) are just as active and in some cases more active than the natural products. Analogues with the natural R configuration at C-10 and the unnatural R configuration at C-4 are most potent. Replacing the natural propionamide N-terminus cap with the more sterically hindered pivaloylamide N-terminus cap leads to enhanced potency. The tetramic acid fragment and the methyl ether on the tetramic acid fragment are essential for activity. The SAR optimized analogue 76 is more selective, easier to synthesize, more potent, and presumed to be more resistant to proteolysis than the natural sintokamides.
Photoinduced and Palladium-Catalyzed Remote Desaturation of Amide Derivatives
Jin, Weiwei,Yu, Shouyun
supporting information, p. 6931 - 6935 (2021/09/11)
A photoinduced and palladium-catalyzed remote desaturation of O-acyl hydroxamides to unsaturated amides under mild conditions has been achieved. The formation of the alkyl Pd(II) intermediate by the recombination of alkyl radical and Pd(I) species is critical to achieve this efficient and selective desaturation of alkanes. This reaction features good site-selectivity, is terminal oxidant-free, and produces moderate to excellent yields for a variety of unsaturated amides. Remarkably, this approach enables late-stage desaturation of complex and biologically important molecules.
DUAL KINASE-BROMODOMAIN INHIBITORS
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Page/Page column 92; 123; 124, (2021/12/12)
Provided herein are compounds of Formula (I) that are dual inhibitors of kinases and bromo-domain proteins. The disclosure also relates to pharmaceutical compositions containing such compounds, methods for using such compounds in the treatment of cancers, particularly, the treatment of multiple myeloma cancers, and to related uses.
A base-controlled switch of SO2 reincorporation in photocatalyzed radical difunctionalization of alkenes
Bellotti, Peter,Glorius, Frank,Paulisch, Tiffany O.,Wang, Huamin,Zhang, Xiaolong
supporting information, p. 3412 - 3424 (2021/12/14)
Control of selectivity is a pivotal challenge in radical chemistry owing to the high reactivity and instability of radical species. Herein, a switchable, base-controlled strategy toward the reincorporation/release of SO2 in photocatalyzed radical difunctionalization of alkenes has been described. By this chemodivergent strategy, a variety of valuable, otherwise difficult-to-access γ-trifluoromethylated ketones and trifluoromethylated sulfonyl ketones can be selectively furnished from the same starting materials. This method features high chemoselectivity, a broad substrate scope, excellent functional group tolerance, and facile scale-up and was applied in a one-pot synthetic procedure. Evaluation of the reaction conditions and mechanistic studies indicate that the choice of base can invert the chemoselectivity of the reaction, demonstrating control over a challenging radical selectivity pattern.
General Access to Modified α-Amino Acids by Bioinspired Stereoselective γ-C?H Bond Lactonization
Vicens, Laia,Bietti, Massimo,Costas, Miquel
supporting information, p. 4740 - 4746 (2020/12/25)
α-Amino acids represent a valuable class of natural products employed as building blocks in biological and chemical synthesis. Because of the limited number of natural amino acids available, and of their widespread application in proteomics, diagnosis, drug delivery and catalysis, there is an increasing demand for the development of procedures for the preparation of modified analogues. Herein, we show that the use of bioinspired manganese catalysts and H2O2 under mild conditions, provides access to modified α-amino acids via γ-C?H bond lactonization. The system can efficiently target 1°, 2° and 3° γ-C?H bonds of α-substituted and achiral α,α-disubstituted α-amino acids with outstanding site-selectivity, good to excellent diastereoselectivity and (where applicable) enantioselectivity. This methodology may be considered alternative to well-established organometallic procedures.
Synthesis of novel phthalimido oxime pseudoesters and evaluation of their cytotoxicity
Mehrez, Asma,Chakroun, Ibtissem,Mtat, Dalila,Mansour, Hédi Ben,Touati, Ridha
, p. 1 - 8 (2020/11/02)
A series of novel optically pure oxime pseudoesters derivatives were synthesized by the reaction of substitute keto oximes with various N-substituted α-amino acids chlorides in the presence of triethylamine and dichloromethane at 0 °C, and their structures were characterized by IR and 1D-NMR methods. The synthesized compounds were tested for their ability to inhibit the proliferation of human colon cancer cells and human epithelial cells. Some of them were revealed to have a significant cytotoxic effect.
