86129-35-3Relevant academic research and scientific papers
Synthesis of Enantiopure Unnatural Amino Acids by Metallaphotoredox Catalysis
Agejas, Javier,Barberis, Mario,De Frutos, Oscar,Faraggi, Tomer M.,García-Cerrada, Susana,MacMillan, David W. C.,Mateos, Carlos,Rincón, Juan A.,Rouget-Virbel, Caroline
, p. 1966 - 1973 (2021/08/18)
We describe herein a two-step process for the conversion of serine to a wide array of optically pure unnatural amino acids. This method utilizes a photocatalytic cross-electrophile coupling between a bromoalkyl intermediate and a diverse set of aryl halides to produce artificial analogues of phenylalanine, tryptophan, and histidine. The reaction is tolerant of a broad range of functionalities and can be leveraged toward the scalable synthesis of valuable pharmaceutical scaffolds via flow technology.
Asymmetric Reduction of Aromatic α-Dehydroamino Acid Esters with Water as Hydrogen Source
Dai, Yuze,Chen, Jingchao,Wang, Zheting,Wang, Ting,Wang, Lin,Yang, Yong,Qiao, Xingfang,Fan, Baomin
supporting information, p. 7141 - 7147 (2021/05/29)
The asymmetric reduction of aromatic α-dehydroamino acid esters with water as the hydrogen source was developed by a Rh/Cu co-catalytic system. The reaction tolerates various functional groups, providing a valuable synthetic tool to access chiral α-amino acid esters readily. Moreover, the present methodology also was applied in the cost-effective and easy to handle preparation of chiral deuterated α-amino esters by using D2O.
Site- and Stereoselective Chemical Editing of Thiostrepton by Rh-Catalyzed Conjugate Arylation: New Analogues and Collateral Enantioselective Synthesis of Amino Acids
Key, Hanna M.,Miller, Scott J.
, p. 15460 - 15466 (2017/11/06)
The synthesis of complex, biologically active molecules by catalyst-controlled, selective functionalization of complex molecules is an emerging capability. We describe the application of Rh-catalyzed conjugate arylation to the modification of thiostrepton, a complex molecule with potent antibacterial properties for which few analogues are known. By this approach, we achieve the site- and stereoselective functionalization of one subterminal dehydroalanine residue (Dha16) present in thiostrepton. The broad scope of this method enabled the preparation and isolation of 24 new analogues of thiostrepton, the biological testing of which revealed that the antimicrobial activity of thiostrepton tolerates the alteration of Dha16 to a range of amino acids. Further analysis of this Rh-catalyzed process revealed that use of sodium or potassium salts was crucial for achieving high stereoselectivity. The catalyst system was studied further by application to the synthesis of amino esters and amides from dehydroalanine monomers, a process which was found to occur with up to 93:7 er under conditions milder than those previously reported for analogous reactions. Furthermore, the addition of the same sodium and potassium salts as applied in the case of thiostrepton leads to a nearly full reversal of the enantioselectivity of the reaction. As such, this study of site-selective catalysis in a complex molecular setting also delivered synergistic insights in the arena of enantioselective catalysis. In addition, these studies greatly expand the number of known thiostrepton analogues obtained by any method and reveal a high level of functional group tolerance for metal-catalyzed, site-selective modifications of highly complex natural products.
NOVEL AMINOPEPTIDASE INHIBITORS AND METHODS OF USE
-
Paragraph 0047, (2017/02/09)
An aminopeptidase inhibitor compound comprising a biaryl, hydroxamic acid based core of formula: wherein X is a 5 or 6-membered ring, and including pharmaceutically acceptable salts and solvates thereof.
Potent dual inhibitors of Plasmodium falciparum M1 and M17 aminopeptidases through optimization of S1 pocket interactions
Drinkwater, Nyssa,Vinh, Natalie B.,Mistry, Shailesh N.,Bamert, Rebecca S.,Ruggeri, Chiara,Holleran, John P.,Loganathan, Sasdekumar,Paiardini, Alessandro,Charman, Susan A.,Powell, Andrew K.,Avery, Vicky M.,McGowan, Sheena,Scammells, Peter J.
, p. 43 - 64 (2016/01/30)
Malaria remains a global health problem, and though international efforts for treatment and eradication have made some headway, the emergence of drug-resistant parasites threatens this progress. Antimalarial therapeutics acting via novel mechanisms are urgently required. Plasmodium falciparum M1 and M17 are neutral aminopeptidases which are essential for parasite growth and development. Previous work in our group has identified inhibitors capable of dual inhibition of PfA-M1 and PfA-M17, and revealed further regions within the protease S1 pockets that could be exploited in the development of ligands with improved inhibitory activity. Herein, we report the structure-based design and synthesis of novel hydroxamic acid analogues that are capable of potent inhibition of both PfA-M1 and PfA-M17. Furthermore, the developed compounds potently inhibit Pf growth in culture, including the multi-drug resistant strain Dd2. The ongoing development of dual PfA-M1/PfA-M17 inhibitors continues to be an attractive strategy for the design of novel antimalarial therapeutics.
Evidence for the role of tetramethylethylenediamine in aqueous negishi cross-coupling: Synthesis of nonproteinogenic phenylalanine derivatives on water
Ross, Andrew J.,Dreiocker, Frank,Schae Fer, Mathias,Oomens, Jos,Meijer, Anthony J.H.M.,Pickup, Barry T.,Jackson, Richard F.W.
scheme or table, p. 1727 - 1734 (2011/05/30)
The structure of the alkylzinc-tetramethylethylenediamine (TMEDA) cluster cation 3 has been determined in the gas phase by a combination of tandem mass spectrometry, infrared multiphoton dissociation (IRMPD) spectroscopy, and DFT calculations. Both sets of experimental results establish the existence of a strongly stabilizing interaction of TMEDA with the zinc cation. High-level DFT calculations on the alkylzinc-TMEDA cluster cation 3 allowed the identification of two low energy conformers, each featuring a four-coordinate zinc atom with a bidentate TMEDA ligand, and internal coordination from the carbonyl group of the Boc group to zinc. The experimental IRMPD spectrum is reproduced with an appropriately weighted combination of the IR spectra of the two conformers identified by theory. DFT calculations on the structure of the alkylzinc halide 2 with coordinated TMEDA using the PCM model of water solvent suggest that TMEDA can promote ionization of the zinc-iodine bond in organozinc iodides under aqueous conditions, providing a credible explanation for the role of TMEDA in stabilizing the carbon-zinc bond. Reaction of the serine-derived iodide 1 with aryl iodides "on water", promoted by nano zinc in the presence of PdCl2 (Amphos) 2 (5 mol %) and TMEDA, leads to the formation of protected phenylalanine derivatives 4 in reasonable yields. In the case of ortho-substituted aryl iodides and aryl iodides that are solids at room temperature, conducting the reaction at 65°C gives improved results. In all cases, the product 5 of reductive dimerization of the iodide 1 is also isolated.
Functionalization of aromatic amino acids via direct C-H activation: Generation of versatile building blocks for accessing novel peptide space
Meyer, Falco-Magnus,Liras, Spiros,Guzman-Perez, Angel,Perreault, Christian,Bian, Jianwei,James, Keith
supporting information; experimental part, p. 3870 - 3873 (2010/11/05)
Functionalized α-amino acid building blocks have been prepared in good yield with high regiocontrol and preservation of stereochemistry via iridium-catalyzed borylation of suitably protected aromatic α-amino acid derivatives. The utility of these systems
FLUORINATION OF ORGANIC COMPOUNDS
-
Page/Page column 117; 118, (2010/07/10)
Methods for fluorinating organic compounds are described herein.
Silver-catalyzed late-stage fluorination
Tang, Pingping,Furuya, Takeru,Ritter, Tobias
supporting information; experimental part, p. 12150 - 12154 (2010/10/04)
Carbon-fluorine bond formation by transition metal catalysis is difficult, and only a few methods for the synthesis of aryl fluorides have been developed. All reported transition-metal-catalyzed fluorination reactions for the synthesis of functionalized arenes are based on palladium. Here we present silver catalysis for carbon-fluorine bond formation. Our report is the first example of the use of the transition metal silver to form carbon-heteroatom bonds by cross-coupling catalysis. The functional group tolerance and substrate scope presented here have not been demonstrated for any other fluorination reaction to date.
Much improved conditions for the Negishi cross-coupling of iodoalanine derived zinc reagents with aryl halides
Ross, Andrew J.,Lang, Hannah L.,Jackson, Richard F. W.
supporting information; experimental part, p. 245 - 248 (2010/04/06)
(Chemical Equation Presented) A combination of Pd2(dba) 3 and SPhos (1:2 molar ratio) is an excellent precatalyst for the Negishi cross-coupling of the serine-derived organozinc reagent 2 with aryl halides, including previously difficult ortho-substituted examples. In the case of meta- and para-substituted aryl halides, Pd-loadings of 0.5 mol % give satisfactory results. Use of 2-iodoaniline as substrate gives the lactam 12 in good yield. 2009 American Chemical Society.
