872709-82-5Relevant articles and documents
Hybrid Palladium Catalyst Assembled from Chiral Phosphoric Acid and Thioamide for Enantioselective β-C(sp3)?H Arylation
Geng, Rui-Long,Gong, Liu-Zhu,Jiang, Hua-Jie,Li, Yang-Yang,Liu, Zi-Ye,Wu, Yun-Dong,Zhang, Xinhao,Zhong, Xiu-Mei
, p. 12774 - 12778 (2020)
A hybrid palladium catalyst assembled from a chiral phosphoric acid (CPA) and thioamide enables a highly efficient and enantioselective β-C(sp3)?H functionalization of thioamides (up to 99 percent yield, 97 percent ee). A kinetic resolution of unsymmetrical thioamides by intermolecular C(sp3)?H arylation can be achieved with high s-factors. Mechanistic investigations have revealed that stereocontrol is achieved by embedding the substrate in a robust chiral cavity defined by the bulky CPA and a neutral thioamide ligand.
Nickel-Catalyzed Asymmetric Kumada Cross-Coupling of Symmetric Cyclic Sulfates
Eno, Meredith S.,Lu, Alexander,Morken, James P.
, p. 7824 - 7827 (2016/07/11)
Nickel-catalyzed enantioselective cross-couplings between symmetric cyclic sulfates and aromatic Grignard reagents are described. These reactions are effective with a broad range of substituted cyclic sulfates and deliver products with asymmetric tertiary carbon centers. Mechanistic experiments point to a stereoinvertive SN2-like oxidative addition of a nickel complex to the electrophilic substrate.
Tunable P-Chiral Bisdihydrobenzooxaphosphole Ligands for Enantioselective Hydroformylation
Tan, Renchang,Zheng, Xin,Qu, Bo,Sader, C. Avery,Fandrick, Keith R.,Senanayake, Chris H.,Zhang, Xumu
supporting information, p. 3346 - 3349 (2016/07/26)
Air-stable and tunable chiral bisdihydrobenzooxaphosphole ligands (BIBOPs) were employed in rhodium-catalyzed asymmetric hydroformylation of various terminal olefins with excellent conversions (>99%), moderate-to-excellent enantioselectivities (up to 95:5 er), and branched to linear ratios (b:l) of up to 400.
On the stereochemistry of the Baker's Yeast-mediated reduction of regioisomeric unsaturated aldehydes: Examples of enantioselectivity switch promoted by substrate-engineering
Brenna, Elisabetta,Fronza, Giovanni,Fuganti, Claudio,Gatti, Francesco G.,Manfredi, Alessia,Parmeggiani, Fabio,Ronchi, Paolo
, p. 94 - 101 (2012/10/30)
The Baker's Yeast (BY) reduction of (Z)-2-chloromethyl-3-arylacrylaldehydes was found to afford (R)-2-methyl-3-aryl-propanols showing high enantiomeric excess values. Deuterium incorporation experiments were performed, in order to investigate the mechanism of the bioreduction: the formation of the corresponding substituted 2-benzylacrylaldehydes, as intermediates to be effectively reduced by Baker's Yeast, was suggested. These intermediates were synthesized and submitted to BY reduction to afford the corresponding saturated (R)-alcohols, thus confirming the conclusions drawn from labelling experiments. The enantioselectivity of their bioreduction was found to be opposite with respect to that observed for the corresponding regioisomeric 2-methylcinnamaldehydes. The preparation of the two enantiomers of 2-methyl-3-aryl-propanols by fermentation of two regioisomers represents an interesting example of substrate-controlled enantioselective reaction.
Structure-activity relationship studies of S1P agonists with a dihydronaphthalene scaffold
Kurata, Haruto,Kusumi, Kensuke,Otsuki, Kazuhiro,Suzuki, Ryo,Kurono, Masakuni,Tokuda, Natsuko,Takada, Yuka,Shioya, Hiroki,Mizuno, Hirotaka,Komiya, Takaki,Ono, Takeji,Hagiya, Hiroshi,Minami, Masashi,Nakade, Shinji,Habashita, Hiromu
scheme or table, p. 144 - 148 (2012/02/16)
Structure-activity relationship (SAR) of sphingosine-1-phosphate receptor agonists with a dihydronaphthalene scaffold was investigated. Compound 1 was modified to improve S1P1 agonistic activity and in vivo peripheral lymphocyte lowering (PLL) activity without impairing selectivity over S1P 3 agonistic activity. A detailed SAR study of the terminal lipophilic part revealed that the introduction of substituents on the propylene linker and the terminal benzene ring influences in vitro and PLL activities. Compound 6n bearing a (S)-methyl group at the 2-position on the propylene linker and chlorine at the para-position on the terminal benzene ring showed potent hS1P1 agonistic activity with excellent selectivity over hS1P 3 and in vivo PLL activity in mice.
COMPOUND HAVING S1P RECEPTOR BINDING POTENCY AND USE THEREOF
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Page/Page column 51, (2010/11/26)
Provided are: a compound represented by formula (I): (wherein ring A and ring D each represent a cyclic group which may have a substituent(s); E and G each represent a bond or a spacer having 1 to 8 atoms in its main chain; L represents a hydrogen atom or a substituent; X represents amino which may have a substituent(s), or a heterocylcic group which contains at least one nitrogen atom and which may have a substituent(s); n represents 0 to 3, in which when n is 2 or more, a plurality of ring A's may be the same or different from one another); a salt thereof; an N-oxide form thereof; a solvate thereof; a prodrug thereof; and a medicament which includes those. The compound represented by formula (I) is capable of binding S1P receptors (in particular, EDG-1 and/or EDG-6), and useful for preventing and/or treating rejection in transplantation, autoimmune diseases, allergic diseases, etc.
A Study of Enantioselective Reduction of para-Substituted 2-Methyl-cinnamaldehydes by Baker's Yeast
Sunjic, Vitomir,Majeric, Maja,Hamersak, Zdenko
, p. 643 - 660 (2007/10/03)
Reduction of a series of para-substituted 2-methyl-cinnamaldehydes (1-7) at 20°C and at pH = 2-3 afforded S-enantiomers of saturated alcohols 8-14 in 20-80% yield and 75 - ≥ 99% enantiomeric excess (e.e.); at 30°C, lower yields and e.e.s were obtained. Relative rates of the formation of allylic alcohols 15-21, catalyzed by alcohol dehydrogenase (ADH), correlate with the Hammett σ+ values of para-substituents, revealing that a more efficient delocalization of the positive charge on carbonylic carbon slow down the reduction rates, whereas no correlation of the electronic properties of the substituents with the rate of C=C double bond reduction, catalyzed by enoate reductase, is observed. On reduction of 3 by dried yeast in 2H2O, α,β-carbon atoms in 10a bear 2H atoms, in accordance with the previously reported hydrogenation of selectively 2H-labeled cinnamic aldehyde and cinnamic alcohol. The accumulated data indicate that the mechanism of the enone C=C bond reduction that comprises nucleophilic attack of the hydride ion species on the β-carbon in the first step, followed by enantioselective protonation on the α-carbon atom.
