876396-82-6Relevant academic research and scientific papers
Stabilization of Cyclic β-Hairpins by Ugi-Reaction-Derived N-Alkylated Peptides: The Quest for Functionalized β-Turns
Ricardo, Manuel G.,Vasco, Aldrin V.,Rivera, Daniel G.,Wessjohann, Ludger A.
, p. 7307 - 7310 (2019)
A solid-phase approach including on-resin Ugi reactions was developed for the construction of β-hairpins. Various N-alkylated dipeptide fragments proved capable of aligning antiparallel β-sheets in a macrocyclic scaffold, thus serving as β-hairpin templates. Gramicidin S was used as the model β-hairpin to compare the Ugi-derived β-turns with the type-II′ β-turn. The results show that the multicomponent incorporation of such N-alkylated residues allows for the simultaneous stabilization and exo-cyclic functionalization of cyclic β-hairpins.
Dual Catalytic Decarboxylative Allylations of α-Amino Acids and Their Divergent Mechanisms
Lang, Simon B.,O'Nele, Kathryn M.,Douglas, Justin T.,Tunge, Jon A.
supporting information, p. 18589 - 18593 (2016/01/25)
The room temperature radical decarboxylative allylation of N-protected α-amino acids and esters has been accomplished via a combination of palladium and photoredox catalysis to provide homoallylic amines. Mechanistic investigations revealed that the stability of the α-amino radical, which is formed by decarboxylation, dictates the predominant reaction pathway between competing mechanisms.
Solid-phase synthesis of piperazinones via disrupted ugi condensation
Treder, Adam P.,Tremblay, Marie-Claude,Yudin, Andrei K.,Marsault, Eric
supporting information, p. 4674 - 4677 (2015/03/30)
The first application of aziridine aldehyde dimers in solid-phase synthesis is reported. The solid-supported disrupted Ugi condensation between an aziridine aldehyde dimer, isonitrile, and backbone-anchored amino acids delivered N-acyl aziridine intermediates, which were reacted with nucleophiles to yield the corresponding piperazinones. Subsequent cleavage from the resin provided a diverse set of 2,3,6-trisubstituted piperazinones starting from various amino acids, aziridine aldehydes, and nucleophiles.
A simple procedure for the esterification of alcohols with sodium carboxylate salts using 1-tosylimidazole (TsIm)
Soltani Rad, Mohammad Navid,Behrouz, Somayeh,Faghihi, Mohammad Ali,Khalafi-Nezhad, Ali
, p. 1115 - 1120 (2008/09/17)
An efficient and selective method for esterification of alcohols using N-(p-toluenesulfonyl)imidazole (TsIm) is described. In this method, alcohols are refluxed with a mixture of RCO2Na (R: alkyl and aryl), TsIm, and triethylamine in the presence of catalytic amounts of tetra-n-butylammonium iodide (TBAI) in DMF to afford the corresponding esters in good yields. This methodology is highly efficient for various structurally diverse alcohols with selectivity for ROH: 1° > 2° > 3°.
