145486-69-7Relevant articles and documents
Solventless mechanosynthesis of N-protected amino esters
Konnert, Laure,Lamaty, Frederic,Martinez, Jean,Colacino, Evelina
, p. 4008 - 4017 (2014/05/20)
Mechanochemical derivatizations of N- or C-protected amino acids were performed in a ball mill under solvent-free conditions. A vibrational ball mill was used for the preparation of N-protected α- and β-amino esters starting from the corresponding N-unmasked precursors via a carbamoylation reaction in the presence of di-tert-butyl dicarbonate (Boc2O), benzyl chloroformate (Z-Cl) or 9-fluorenylmethoxycarbonyl chloroformate (Fmoc-Cl). A planetary ball mill proved to be more suitable for the synthesis of amino esters from N-protected amino acids via a one-pot activation/esterification reaction in the presence of various dialkyl dicarbonates or chloroformates. The spot-to-spot reactions were straightforward, leading to the final products in reduced reaction times with improved yields and simplified work-up procedures.
SUBSTITUTED PYRAZOLE AND TRIAZOLE COMPOUNDS AS KSP INHIBITORS
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Page/Page column 72, (2008/12/05)
Disclosed are new substituted pyrazole and triazole compounds of Formula (I) and pharmaceutically acceptable salts, esters or prodrugs thereof, compositions of the derivatives together with pharmaceutically acceptable carriers, and uses thereof
Preparation and structure of β-peptides consisting of geminally disubstituted β2,2- and β3,3-amino acids: A turn motif for β- peptides
Seebach, Dieter,Abele, Stefan,Sifferlen, Thierry,Haenggi, Martin,Gruner, Sibylle,Seiler, Paul
, p. 2218 - 2243 (2007/10/03)
We report on the synthesis of new and previously described β-peptides (1-6), consisting of up to twelve β2,2- or β3,3-geminally disubstituted β-amino acids which do not fit into any of the secondary structural patterns of β-peptides, hitherto disclosed. The required 2,2- and 3,3-dimethyl derivatives of 3-aminopropanoic acid are readily obtained from 3-methylbut-2-enoic acid and ammonia (Scheme 1) and from Boc-protected methyl 3-aminopropanoate by enolate methylation (Scheme 2). Protected (Boc for solution-, Fmoc for solid-phase syntheses) 1- (aminomethyl)cycloalkanecarboxylic-acid derivatives (with cyclopropane, cyclobutane, cyclopentane, and cyclohexane rings) are obtained from 1- cyanocycloalkanecarboxylates and the corresponding dihaloalkanes (Scheme 3). Fully 13C- and 15N-labeled 3-amino-2,2-dimethylpropanoic-acid derivatives were prepared from the corresponding labeled precursors (see asterixed formula numbers and Scheme 4). Coupling of these amino acids was achieved by methods which we had previously employed for other β-peptide syntheses (intermediates 18-23). Crystal structures of Boc-protected geminally disubstituted amino acids (16a-d) and of the corresponding tripeptide (23a), as well as NMR and IR spectra of an isotopically labeled β-hexapeptide (2a*) are presented (Figs. 1-4) and discussed. The tripeptide structure contains a ten-membered H-bonded ring which is proposed to be a turn-forming motif for β-peptides (Fig. 2).
