16372-51-3Relevant academic research and scientific papers
N-Ammonium Ylide Mediators for Electrochemical C-H Oxidation
Saito, Masato,Kawamata, Yu,Meanwell, Michael,Navratil, Rafael,Chiodi, Debora,Carlson, Ethan,Hu, Pengfei,Chen, Longrui,Udyavara, Sagar,Kingston, Cian,Tanwar, Mayank,Tyagi, Sameer,McKillican, Bruce P.,Gichinga, Moses G.,Schmidt, Michael A.,Eastgate, Martin D.,Lamberto, Massimiliano,He, Chi,Tang, Tianhua,Malapit, Christian A.,Sigman, Matthew S.,Minteer, Shelley D.,Neurock, Matthew,Baran, Phil S.
supporting information, p. 7859 - 7867 (2021/05/26)
The site-specific oxidation of strong C(sp3)-H bonds is of uncontested utility in organic synthesis. From simplifying access to metabolites and late-stage diversification of lead compounds to truncating retrosynthetic plans, there is a growing need for new reagents and methods for achieving such a transformation in both academic and industrial circles. One main drawback of current chemical reagents is the lack of diversity with regard to structure and reactivity that prevents a combinatorial approach for rapid screening to be employed. In that regard, directed evolution still holds the greatest promise for achieving complex C-H oxidations in a variety of complex settings. Herein we present a rationally designed platform that provides a step toward this challenge using N-ammonium ylides as electrochemically driven oxidants for site-specific, chemoselective C(sp3)-H oxidation. By taking a first-principles approach guided by computation, these new mediators were identified and rapidly expanded into a library using ubiquitous building blocks and trivial synthesis techniques. The ylide-based approach to C-H oxidation exhibits tunable selectivity that is often exclusive to this class of oxidants and can be applied to real-world problems in the agricultural and pharmaceutical sectors.
Facile Synthesis of Alkylidene Phthalides by Rhodium-Catalyzed Domino C?H Acylation/Annulation of Benzamides with Aliphatic Carboxylic Acids
Liu, Sien,He, Bangyue,Li, Hongyi,Zhang, Xiaofeng,Shang, Yaping,Su, Weiping
supporting information, p. 15628 - 15633 (2021/10/05)
The Rh-catalyzed ortho-C(sp2)?H functionalization of 8-aminoquinoline-derived benzamides with aliphatic acyl fluorides generated in situ from the corresponding acids has been developed. This reaction initiated with 8-aminoquinoline-directed ortho-C(sp2)?H acylation, which was accompanied by subsequent intramolecular nucleophilic acyl substitution of amide group to produce alkylidene phthalides This approach exhibits high stereo-selectivity for Z-isomer products, and tolerates a variety of functional groups as well as aliphatic carboxylic acids with diverse structural scaffolds.
CASPASE INHIBITOR AND PHARMACEUTICAL COMPOSITION, USE AND THERAPEUTIC METHOD THEREOF
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Paragraph 0374; 0375, (2019/04/05)
Disclosed are a class of compounds as a caspase inhibitor, and in particular the compound as shown in formula (I) or a pharmaceutically acceptable salt thereof, and the use of the compound in treating caspase-related diseases.
Memory of chirality of tertiary aromatic amides: A simple and efficient method for the enantioselective synthesis of quaternary α-amino acids
Branca, Mathieu,Pena, Sebastien,Guillot, Regis,Gori, Didier,Alezra, Valerie,Kouklovsky, Cyrille
supporting information; experimental part, p. 10711 - 10718 (2009/12/04)
A new methodology for the asymmetric synthesis of quaternary R-substituted amino acids using memory of chirality has been developed. The strategy utilizes the dynamic axial chirality of tertiary aromatic amides to memorize the initial chirality of an α-amino acid during an enolization step. Starting from five different L-amino acids, the corresponding oxazolidin-5-ones containing a tertiary aromatic amide group have been synthesized in one step and then alkylated with various electrophiles, with good yields and enantioselectivities (up to 96% and up to >99% after recrystallization). One-step deprotection affords enantioenriched or enantiopure quaternary α-amino acids. We describe here the optimization process, the results obtained in each series and a plausible explanation, based on NMR studies, DFT calculations and crystallographic structures. The methodology presented herein constitutes an efficient synthesis of enantiopure quaternary R-amino acids (three steps only) starting from tertiary L-amino acids, without any external source of chirality.
Directed lithiations: The effect of varying directing group orientation on competitive efficiencies for a series of tertiary amide, secondary amide, and alkoxide directed ortho lithiations
Beak, Peter,Kerrick, Shawn T.,Gallagher, Donald J.
, p. 10628 - 10636 (2007/10/02)
Significant differences for competitive efficiencies in directed ortho lithiations for single functional groups in three series, the secondary benzamides 1-4, the tertiary benzamides 5-11, and the benzylic alcohols 12-17, are reported. For both amide seri
Chromatographic Separation of Enantiomers and Barriers to Enantiomerization of Axially Chiral Aromatic Carboxamides
Cuyegkeng, Maria Assunta,Mannschreck, Albrecht
, p. 803 - 810 (2007/10/02)
The enantiomers (M) and (P) of a series of similar aromatic carboxamides have been, for the first time, investigated analytically and enriched preparatively by liquid chromatography on triacetylcellulose.Enantiomeric purities (7-99percent), specific rotations, and barriers to rotation about the C(sp2)-C(sp2) bond (87 - 120 kJ/mol, Table 5) were determined.These energies are discussed in terms of the size of ortho substituents and of the buttressing effects by meta substituents.
