1795-96-6Relevant academic research and scientific papers
Synthesis of pharmacophores containing a prolinate core using a multicomponent 1,3-dipolar cycloaddition of azomethine ylides
Selva, Elisabet,Castelló, Luis M.,Mancebo-Aracil, Juan,Selva, Verónica,Nájera, Carmen,Foubelo, Francisco,Sansano, José M.
, p. 6840 - 6846 (2017)
A multicomponent 1,3-dipolar cycloaddition between heterocyclic aldehydes, amino esters and dipolarophiles is efficiently promoted by silver acetate as catalyst, and depending on the nature of the heterocycle and its reactivity the reaction requires 70 °C or rt to complete. Selected pharmacophores anchored to a formyl group are chromone, 5-methoxyindole, pyridoxal surrogates and a very attractive uracyl derivative. The preference of each tested amino esters towards different dipolarophiles is discussed. At the end, a selective reduction of the ester group allows to obtain a very interesting dideoxiazanucleoside derivative.
Novel ozone-mediated cleavage of the benzhydryl protecting group from aziridinyl esters
Patwardhan, Aniruddha P.,Lu, Zhenjie,Pulgam, V. Reddy,Wulff, William D.
, p. 2201 - 2204 (2005)
(Chemical Equation Presented) N-Benzhydryl aziridines-2-carboxylates can be readily obtained from the catalytic asymmetric aziridination reaction from N-benzhydrylimines and ethyl diazoacetate. Cleavage of the benzhydryl group by hydrogenolysis leads to ring opening when R = aryl. Surprisingly, ozone will selectively oxidize the benhydryl group in these aziridines even when R is an aryl group. This allows for a new deprotection strategy for these aziridines whose generality is explored.
α-Azido Esters in Depsipeptide Synthesis: C-O Bond Cleavage during Azido Group Reduction
Lohani, Chuda Raj,Soley, Jacob,Kralt, Braden,Palmer, Michael,Taylor, Scott D.
, p. 11831 - 11840 (2016)
α-Azido esters, when treated with dithiothreitol (DTT)/diisopropylethylamine (DIPEA), undergo both azido group reduction to give α-amino esters and C-O bond cleavage to give triazoles. The extent of triazole formation depends upon leaving group ability. Some C-O bond cleavage via triazole formation was also found to occur when a resin-bound peptide, which contained a terminal α-azido ester group, was treated with DTT/DIPEA. C-O bond cleavage also took place when this peptide was treated with PPh3, PBu3, or PMe3; however, in these cases, C-O bond cleavage occurred via either triazole formation and/or hydrolysis of the ester bond in the iminophosphorane intermediate to give betaines. The mechanism that dominated for C-O bond cleavage depended upon the phosphine that was used for azido group reduction. C-O bond cleavage during reduction of the azido group in the peptide was minimized by performing the reduction with PBu3 in the presence of a symmetric anhydride derived from an amino acid in dry THF followed by the addition of water. Surprisingly, these conditions provided the amine as the major product, while the expected amide was formed as a minor product. These conditions were employed in an improved synthesis of an analogue of the cyclic lipodepsipeptide antibiotic daptomycin.
Dynamic Kinetic resolution of α-amino acid esters in the presence of aldehydes
Schichl, Daniel A.,Enthaler, Stephan,Holla, Wolfgang,Riermeier, Thomas,Kragl, Udo,Beller, Matthias
, p. 3506 - 3512 (2008)
A convenient procedure for the racemization of α-amino acid esters in the presence of catalytic amounts of salicylaldehydes is described. The combination of this racemization protocol with lipase-catalyzed ester hydrolysis allows successful dynamic kinetic resolution of various α-amino acid esters. The corresponding α-amino acids are obtained in high yield and optical purity. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Dichloromeldrum's acid (DiCMA): A practical and green amine dichloroacetylation reagent
Heard, David M.,Lennox, Alastair J.J.
supporting information, p. 3368 - 3372 (2021/05/06)
Dichloromeldrum's acid is introduced as a bench-stable, nonvolatile reagent for the dichloroacetylation of anilines and alkyl amines to produce α,α-dichloroacetamides, which are important motifs for medicinal chemistry. Products are formed in good to excellent yields with reagent grade solvents, and, as the only byproducts are acetone and CO2, no column chromatography is required. Thus, this reagent is practical, efficient, and green for the dichloroacetylation of primary amines.
Stereospecific Synthesis of 3,4-Dihydro-2 H-naphtho-1,4-oxazin-2-ones by Unification of Benzoxepine-4-carboxylates with Chiral Amino Acid Ethyl Esters
Bhimapaka, China Raju,Kasagani, Veera Prasad,Kurma, Siva Hariprasad
supporting information, p. 2976 - 2983 (2020/03/23)
A novel and efficient stereocontrolled method has been developed for the preparation of chiral 3,4-dihydro-2H-naphtho[1,2-b][1,4]oxazin-2-ones by the reaction of benzoxepine-4-carboxylates with chiral amino acid ethyl esters for the first time. The chiral 3,4-dihydro-2H-naphtho-1,4-oxazinones have been achieved in one step by the formation of C-N, C-C, and C-O bonds.
Reductive Alkylation of Amines with Carboxylic Ortho Esters
Kadyrov, Renat,Moebus, Konrad
supporting information, p. 3352 - 3357 (2020/07/04)
We have demonstrated for the first time that carboxylic ortho esters could be used as an alkylating agent in the reductive alkylation of amines. A variety of amines, including amino acid esters, were alkylated affording mono-alkylated products with high selectivity in practical to high yields using standard heterogeneous catalysts. By applying acyclic ortho esters alkylation was completed at room temperature. (Figure presented.).
The effect of solvents on the thermal degradation products of two Amadori derivatives
Li, Rui,Zhang, Shiyi,Zhang, Yudan,Zhao, Mingqin
, p. 9309 - 9317 (2020/03/23)
To enrich the flavor additives of the Maillard reaction, two Amadori analogs, N-(1-deoxy-d-fructosyl-1-yl)-l-phenylalanine ester (Derivative 1) and di-O-isopropylidene-2,3:4,5-?-d-fructopyranosyl phenylalanine ester (Derivative 2), were chemically synthes
Design and synthesis of a s-triazene based asymmetric organocatalyst and its application in enantioselective alkylation
Mangawa, Shrawan K.,Singh, Ashawani K.,Awasthi, Satish K.
, p. 61144 - 61147 (2015/08/03)
A very efficient chiral organocatalyst was prepared from the readily available cyanuric chloride. The asymmetric catalyst exhibited a highly enantioselective catalytic performance for the alkylation of a glycinate Schiff base, which provides a useful procedure for the enantioselective synthesis of structurally diverse natural and unnatural α-alkyl-α-amino acids.
One-pot multifunctional catalysis with NNN-Pincer Zr-MOF: Zr base catalyzed condensation with Rh-catalyzed hydrogenation
Rasero-Almansa, Antonia M.,Corma, Avelino,Iglesias, Marta,Sánchez, Félix
, p. 3092 - 3100 (2013/10/21)
We describe the postsynthetic modification of Zr-based metal organic frameworks (MOFs) containing chiral NNN-pincer ligands based on aminopyridineimines, as well as the subsequent formation of (NNN)-M-Zr-MOF complexes (M=Rh, Ir). With these new multifunct
