58177-77-8Relevant articles and documents
Decarboxylative Radical Addition to Methylideneoxazolidinones for Stereocontrolled Synthesis of Selectively Protected Diamino Diacids
Annadate, Ritesh,Beadle, Jonathan,Hsiao, Yu-Ting,Pascoe, Cameron,Vederas, John C.
, p. 7270 - 7273 (2021/10/01)
Syntheses of stereochemically pure and selectively protected diamino diacids can be achieved by redox decarboxylation of distal N-hydroxyphthalimide esters of protected aspartic, glutamic or α-aminoadipic acids via radical addition to methylideneoxazolidinones. The products are useful for solid-supported syntheses of robust bioactive carbocyclic peptide analogs. Yields of reactive primary radical addition are superior to those of more stabilized radicals, and the reaction fails if the alkylideneoxazolidinone has a methyl substituent on its terminus (i.e., 13a/13b).
μ-Oxo-Dinuclear-Iron(III)-Catalyzed O-Selective Acylation of Aliphatic and Aromatic Amino Alcohols and Transesterification of Tertiary Alcohols
Horikawa, Rikiya,Fujimoto, Chika,Yazaki, Ryo,Ohshima, Takashi
supporting information, p. 12278 - 12281 (2016/08/24)
A highly chemoselective and reactive μ-oxo-dinuclear iron(III) salen catalyst for transesterification was developed. The developed iron complex catalyzed acylation of aliphatic amino alcohols with nearly perfect O-selectivity, even when using activated esters, for which chemoselectivity is more difficult to control. In addition, O-selective transesterification of aromatic amino alcohols was achieved for the first time. The high activity of the iron complex enabled the use of sterically congested tertiary alcohols, including unprecedented tert-butanol.
Cyclic phosphoramidates as prodrugs of 2′-C-methylcytidine
Meppen, Malte,Pacini, Barbara,Bazzo, Renzo,Koch, Uwe,Leone, Joseph F.,Koeplinger, Kenneth A.,Rowley, Michael,Altamura, Sergio,Di Marco, Annalise,Fiore, Fabrizio,Giuliano, Claudio,Gonzalez-Paz, Odalys,Laufer, Ralph,Pucci, Vincenzo,Narjes, Frank,Gardelli, Cristina
scheme or table, p. 3765 - 3770 (2009/12/24)
The currently approved treatment for hepatitis C virus infections is a combination of Ribavirin and pegylated Interferon. It leads to a sustained virologic response in approximately only half of the patients treated. For this reason there is an urgent need of new therapeutic agents. 2′-C-Methylcytidine is the first nucleoside inhibitor of the HCV NS5B polymerase that was efficacious in reducing the viral load in patients infected with HCV. The application of a monophosphate prodrug approach based on unprecedented cyclic phosphoramidates is reported. Our SAR studies led to compounds that are efficiently converted to the active triphosphate in human hepatocytes.
9-(4-Bromophenyl)-9-fluorenyl as a safety-catch nitro gen protecting group
Surprenant, Simon,Lubell, William D.
, p. 848 - 851 (2007/10/03)
The 9-(4-bromophenyl)-9-fluorenyl (BrPhF) group has been developed as a novel safety-catch amine protection. This relatively acid-stable protecting group can be successfully activated by palladium-catalyzed cross-coupling reaction of the aryl bromide with morpholine and then cleaved effectively under mild conditions using dichloroacetic acid and triethylsilane. Complementary conditions are reported for selective removal of the BrPhF group in the presence of tert-butyl esters and carbamates as well as deprotection of tert-butyl esters and carbamates in the presence of BrPhF amines.
Molecular discrimination of N-protected amino acid esters by a self-assembled cylindrical capsule: spectroscopic and computational studies.
Hayashida, Osamu,Sebo, Lubomir,Rebek Jr., Julius
, p. 8291 - 8298 (2007/10/03)
A self-assembled, cylindrical capsule was used to bind N-alpha-protected amino acid esters. The reversible encapsulation was studied using NMR spectroscopy in deuterated mesitylene solution and by computer-aided molecular modeling. BOC-L-alanine alkyl est
Selective nitrolytic deprotection of N-BOC-amines and N-BOC-amino acids derivatives
Strazzolini, Paolo,Melloni, Tiziana,Giumanini, Angelo G
, p. 9033 - 9043 (2007/10/03)
The extension of the deprotection procedure using HNO3 in CH2Cl2 to a number of appropriately selected N-BOC-masked amines and derivatives of natural amino acids was investigated. The method was found to work effectively with almost all tested substrates, with the exception of activated aromatic amines and heterocycles which underwent unavoidable faster oxidation. Alanine, phenylalanine, serine and lysine derivatives were efficiently deprotected, as well as dipeptide Ala-Phe, preserving the configuration of the substrates and without affecting copresent Z and ester functions, with a remarkable selectivity towards acid sensitive t-butyl esters. The obtained amino acids esters, isolated and characterized in the form of nitrates salts, proved to be suitable intermediates to be used in peptide synthesis.
ISOPROPENYL CHLOROCARBONATE (IPCC) IN AMINO ACID AND PEPTIDE CHEMISTRY: ESTERIFICATION OF N-PROTECTED AMINO ACIDS; APPLICATION TO THE SYNTHESIS OF THE DEPSIPEPTIDE VALINOMYCIN
Zeggaf, Choukri,Poncet, Joel,Jouin, Patrick,Dufour, Marie-Noelle,Castro, Bertrand
, p. 5039 - 5050 (2007/10/02)
Esterification of N-protected α-amino acids was achieved via isopropenyl chlorocarbonate (IPCC) activation.In situ alcoholysis of the unstable mixed anhydride intermediate was catalised by 4-(dimethylamino)pyridine (DMAP).Competing isopropenyl ester formation was negligible when using methylene chloride as the solvent.A variety of esters from primary and secondary alcohols were obtained with good yields (60 to 90 percent), and even the more hindered tertiobutyl alcohol gave acceptable yields under more drastic conditions.The improvement in depsipeptide synthetic methodology is illustrated by preparation of the antibiotic valinomycin, using IPCC for ester bond formation, and BOP reagent for peptide coupling and the last-step cyclisation.
MANIPULATION OF THE CARBOXYL GROUPS OF α-AMINO-ACIDS AND PEPTIDES USING RADICAL CHEMISTRY BASED ON ESTERS OF N-HYDROXY-2-THIOPYRIDONE
Barton, Derek H. R.,Herve, Yolande,Potier, Pierre,Thierry, Josiane
, p. 5479 - 5486 (2007/10/02)
Photolysis of α-amino-acid or peptide esters derived from N-hydroxy-2-thiopyridone in the presence of t-butylthiol affords the expected decarboxylation products in good yield.The reaction can be applied to the α-carboxyl or to the side chain carboxyl of g