81477-94-3Relevant articles and documents
Access to α,α-Disubstituted Disilylated Amino Acids and Their Use in Solid-Phase Peptide Synthesis
Fanelli, Roberto,Salah, Khoubaib Ben Haj,Inguimbert, Nicolas,Didierjean, Claude,Martinez, Jean,Cavelier, Florine
, p. 4498 - 4501 (2015)
A concise synthetic pathway yielding to hydrophobic α,α-disubstituted disilylated amino acids based on a hydrosilylation reaction is described. As a first example of utilization in solid-phase peptide synthesis, TESDpg was introduced in replacement of Aib in an alamethicin sequence, leading to analogues with modified physicochemical properties and conserved helical structures. This study highlights the potential of these new amino acids as tools for peptide modulation.
Scandium(III) Triflate Catalyzed Direct Synthesis of N-Unprotected Ketimines
Hirazawa, Yoshinobu,Kadota, Tetsuya,Kondo, Yuta,Morimoto, Hiroyuki,Morisaki, Kazuhiro,Ohshima, Takashi
supporting information, p. 120 - 125 (2020/02/20)
N-Unprotected ketimines are useful substrates and intermediates for synthesizing valuable nitrogen-containing compounds, but their potential applicability is limited by the available synthetic methods. To address this issue, we report a scandium(III) triflate catalyzed direct synthesis of N-unprotected ketimines. Using commercially available reagents and Lewis acid catalysts, ketones were directly transformed into the corresponding N-unprotected ketimines in high yields with broad functional group tolerance, even in multigram scales. The reactions were readily applicable for one-pot synthesis of important compounds such as a glycine Schiff base without isolation of N-unprotected ketimine intermediates. Preliminary mechanistic studies to clarify the reaction mechanism are also described.
Enantio- and Diastereoselective Synthesis of β-Aryl-β-pyrazolyl α-Amino Acid Esters via Copper-Catalyzed Reaction of Azomethine Ylides with Benzylidenepyrazolones
Gong, Yan-Chuan,Wang, Yue,Li, Er-Qing,Cui, Hao,Duan, Zheng
supporting information, (2019/02/07)
A fully stereoselective synthesis of unnatural chiral β-aryl-β-pyrazolyl α-amino acid esters via copper-catalyzed addition reactions of azomethine ylides with benzylidenepyrazolones bearing two contiguous stereogenic centers was developed. A 1H-pyrazol-5-ol was introduced by the aromatization of 3H-pyrazol-3-one in the reaction. The transformation operated at room temperature and afforded β-1H-pyrazol-5-ol-α-amino esters in high yields with good to excellent levels of diastereo- and enantioselectivity.
