27786-78-3Relevant academic research and scientific papers
Ligand-Accelerated Palladium(II)-Catalyzed Enantioselective Amination of C(sp2)-H Bonds
Cheng, Xiu-Fen,Fei, Fan,Li, Yan,Hou, Yi-Ming,Zhou, Xin,Wang, Xi-Sheng
, p. 6394 - 6398 (2020)
The first example of the Pd(II)-catalyzed enantioselective amination of aryl C-H bonds is reported. The key to the successful realization of this asymmetric catalytic transformation was the identification of mono-N-protected α-amino-O-methylhydroxamic acid (MPAHA) ligands, which promote reactivity under mild conditions and control enantioselectivity. The counteranions in the solvent medium, hexafluoroacetylacetate and acetate, were also found to play key roles in stereocontrol and reactivity enhancement.
LAT1 activity of carboxylic acid bioisosteres: Evaluation of hydroxamic acids as substrates
Zur, Arik A.,Chien, Huan-Chieh,Augustyn, Evan,Flint, Andrew,Heeren, Nathan,Finke, Karissa,Hernandez, Christopher,Hansen, Logan,Miller, Sydney,Lin, Lawrence,Giacomini, Kathleen M.,Colas, Claire,Schlessinger, Avner,Thomas, Allen A.
, p. 5000 - 5006 (2016/10/05)
Large neutral amino acid transporter 1 (LAT1) is a solute carrier protein located primarily in the blood–brain barrier (BBB) that offers the potential to deliver drugs to the brain. It is also up-regulated in cancer cells, as part of a tumor's increased metabolic demands. Previously, amino acid prodrugs have been shown to be transported by LAT1. Carboxylic acid bioisosteres may afford prodrugs with an altered physicochemical and pharmacokinetic profile than those derived from natural amino acids, allowing for higher brain or tumor levels of drug and/or lower toxicity. The effect of replacing phenylalanine's carboxylic acid with a tetrazole, acylsulfonamide and hydroxamic acid (HA) bioisostere was examined. Compounds were tested for their ability to be LAT1 substrates using both cis-inhibition and trans-stimulation cell assays. As HA-Phe demonstrated weak substrate activity, its structure–activity relationship (SAR) was further explored by synthesis and testing of HA derivatives of other LAT1 amino acid substrates (i.e., Tyr, Leu, Ile, and Met). The potential for a false positive in the trans-stimulation assay caused by parent amino acid was evaluated by conducting compound stability experiments for both HA-Leu and the corresponding methyl ester derivative. We concluded that HA's are transported by LAT1. In addition, our results lend support to a recent account that amino acid esters are LAT1 substrates, and that hydrogen bonding may be as important as charge for interaction with the transporter binding site.
Transition-Metal-Free Synthesis of N-Aryl Hydroxamic Acids via Insertion of Arynes
Zhang, Lanlan,Geng, Yu,Jin, Zhong
, p. 3542 - 3552 (2016/05/24)
An efficient and transition-metal-free N-arylation of amides via the insertion of arynes into the N-H bonds in the N-alkoxy amides is described. A variety of the reactive functional groups including the reactive aldehyde carbonyl group, furan ring, carbon-carbon double bonds, and free N-H bond of indole are found to be compatible with this process. In particular, the protocol is applicable in the synthesis of structurally diverse N-aryl hydroxamates and hydroxamic acids derived from N-protecting amino acids and peptides. In the presence of multiple amide N-H bonds, the N-arylation reaction can proceed selectively in the N-H bonds of terminal N-OBn amides giving rise to the desired N-aryl hydroxamates.
Amino acid derived amides and hydroxamic acids as ligands for asymmetric transfer hydrogenation in aqueous media
Ahlford, Katrin,Adolfsson, Hans
scheme or table, p. 1118 - 1121 (2012/01/15)
Amides and hydroxamic acids derived from α-amino acids were evaluated as ligands in combination with rhodium and iridium half-sandwich complexes in asymmetric transfer hydrogenation (ATH) of ketones. The reactions were performed in aqueous media using lithium formate as hydride source. The catalyst systems turned out to be highly efficient and ee's up to 90% were obtained.
