79069-54-8Relevant academic research and scientific papers
Probing α-Amino Aldehydes as Weakly Acidic Pronucleophiles: Direct Access to Quaternary α-Amino Aldehydes by an Enantioselective Michael Addition Catalyzed by Br?nsted Bases
García-Urricelqui, Ane,de Cózar, Abel,Mielgo, Antonia,Palomo, Claudio
supporting information, p. 2483 - 2492 (2020/12/25)
The high tendency of α-amino aldehydes to undergo 1,2-additions and their relatively low stability under basic conditions have largely prevented their use as pronucleophiles in the realm of asymmetric catalysis, particularly for the production of quaternary α-amino aldehydes. Herein, it is demonstrated that the chemistry of α-amino aldehydes may be expanded beyond these limits by documenting the first direct α-alkylation of α-branched α-amino aldehydes with nitroolefins. The reaction produces densely functionalized products bearing up to two, quaternary and tertiary, vicinal stereocenters with high diastereo- and enantioselectivity. DFT modeling leads to the proposal that intramolecular hydrogen bonding between the NH group and the carbonyl oxygen atom in the starting α-amino aldehyde is key for reaction stereocontrol.
Synthesis of Enantiomerically Pure 3-Substituted Piperazine-2-acetic Acid Esters as Intermediates for Library Production
Reddy Guduru, Shiva Krishna,Chamakuri, Srinivas,Raji, Idris O.,MacKenzie, Kevin R.,Santini, Conrad,Young, Damian W.
, p. 11777 - 11793 (2018/09/27)
The piperazine heterocycle is broadly exploited in FDA-approved drugs and biologically active compounds, but its chemical diversity is usually limited to ring nitrogen substitutions, leaving the four carbon atoms underutilized. Using an efficient six-step synthesis, chiral amino acids were transformed into 3-substituted piperazine-2-acetic acid esters as diastereomeric mixtures whose cis and trans products (dr 0.56 a? 2.2:1, respectively) could be chromatographically separated. From five amino acids (both antipodes) was obtained a complete matrix of 20 monoprotected chiral 2,3-disubstituted piperazines, each as a single absolute stereoisomer, all but one in multigram quantities. In keeping with our overall purpose of constructing more Csp3-enriched compound libraries for drug discovery, these diverse and versatile piperazines can be functionalized on either nitrogen atom, allowing them to be used as scaffolds for parallel library synthesis and as intermediates for the production of novel piperazine compounds.
Effects of the Backbone and Chemical Linker on the Molecular Conductance of Nucleic Acid Duplexes
Beall, Edward,Ulku, Selma,Liu, Chaoren,Wierzbinski, Emil,Zhang, Yuqi,Bae, Yookyung,Zhang, Peng,Achim, Catalina,Beratan, David N.,Waldeck, David H.
, p. 6726 - 6735 (2017/05/29)
Scanning tunneling microscope break junction measurements are used to examine how the molecular conductance of nucleic acids depends on the composition of their backbone and the linker group to the electrodes. Molecular conductances of 10 base pair long h
Gold-catalyzed synthesis of enantioenriched furfurylamines from amino acids
Guieu, Benjamin,Le Roch, Myriam,David, Michèle,Gouault, Nicolas
, p. 868 - 875 (2015/08/18)
Abstract A convenient gold-catalyzed asymmetric synthesis of polysubstituted furfurylamines starting from amino acids has been achieved. The cyclization proceeded under mild conditions and generally provided the furan or iodofuran derivatives in good to e
A mild multistep conversion of n-protected α-amino acids into N-protected β3-amino acids utilizing the Nef reaction
Sleebs, Brad E.,Nguyen, Nghi H.,Hughes, Andrew B.
supporting information, p. 747 - 751 (2013/05/08)
Current methods of homologation of α-amino acids to β-amino acids have limitations. To overcome these shortfalls the Nef reaction has been utilized in the multistep synthesis of β3-amino acids from α-amino acids. In this approach, N-protected a
Synthesis of threo-β-aminoalcohols from aminoaldehydes via chelation-controlled additions. Total synthesis of l-threo sphingosine and safingol
Jung, Michael E.,Yi, Sung Wook
supporting information; experimental part, p. 4216 - 4220 (2012/08/29)
Chelation-controlled addition of organocuprates to N-carbamoyl aminoaldehydes, prepared from functionalized amino acids, generated predominately the threo-β-amino alcohol derivatives through chelation with the carbamoyl moiety. The carbamate group is a stronger chelating group than other potentially good chelators, for example ethers, esters, thioethers, and gives good diastereoselectivity with cuprates. Thus addition of lithium divinylcuprate to the aldehyde generated from the serine derivative 25 in the presence of extra copper for chelation afforded the threo compound 26 in 83% yield. Cross-metathesis and cleavage of the protecting groups furnished l-threo sphingosine 21. In addition the lyso-sphingolipid protein kinase C inhibitor, safingol, 22, was prepared from commercially available O-benzyl N-BOC serine 28 in six steps and 56% overall yield by this method.
CATHEPSIN S INHIBITORS
-
Page/Page column 26, (2011/06/25)
Cathepsin S inhibitors having formula (I), (II), (III) or (IV) as shown in the specification. These inhibitors can be used to treat cancer and autoimmune/inflammatory diseases.
10A-AZALIDE COMPOUND HAVING 4-MEMBERED RING STRUCTURE
-
Page/Page column 51, (2011/04/14)
A 10a-azalide compound having a 4-membered ring structure crosslinked at the 10a- and 12-positions, which is represented by the formula (I), and is effective on even Haemophilus influenzae, or erythromycin resistant bacteria (e.g., resistant pneumococci and streptococci).
Design and synthesis of α-ketoamides as cathepsin s inhibitors with potential applications against tumor invasion and angiogenesis
Chen, Jo-Chun,Uang, Biing-Jiun,Lyu, Ping-Chiang,Chang, Jang-Yang,Liu, Ko-Jiunn,Kuo, Ching-Chuan,Hsieh, Hsing-Pang,Wang, Hsin-Chieh,Cheng, Chao-Sheng,Chang, Yi-Hsun,Chang, Margaret Dah-Tsyr,Chang, Wun-Shaing Wayne,Lin, Chun-Cheng
scheme or table, p. 4545 - 4549 (2010/08/19)
A series of small molecules bearing an α-ketoamide warhead were synthesized and evaluated for their ability to inhibit cathepsin S, a key proteolytic enzyme upregulated in many cancers during tumor progression and metastasis. Most of the synthetic compounds were noncytotoxic, but several robustly inhibited cathepsin S (IC50 10 nM) and potently suppressed cell migration, invasion, and capillary tube formation. These results highlight the potential of α-ketoamide therapy for preventing or delaying cancer spread.
Convergent synthesis of α-ketoamide inhibitors of Pin1
Xu, Guoyan G.,Etzkorn, Felicia A.
supporting information; experimental part, p. 696 - 699 (2010/04/02)
(Chemical Equation Presented) A convergent synthesis of α-ketoamlde Inhibitors of Plni Is described. An a-hydroxyorthothloester derivative of Ser was reacted directly with an amine synthon. The reaction was catalyzed by HgO and HgCl2 to form a-
