- Catalytic asymmetric synthesis of diazabicyclo[3.1.0]hexanes by 1,3-dipolar cycloaddition of azomethine ylides with azirines
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Substituted 1,3-diazabicyclo[3.1.0]hexanes with two contiguous quaternary stereocentres are readily prepared by catalytic asymmetric [3+2] cycloaddition of a-substituted iminoesters with azirines. High diastereoselectivities and enantioselectivities (up to 98% ee) are achieved using CuI/(R)-Fesulphos as the catalytic system.
- Adrio, Javier,Carretero, Juan C.,Díaz-Tendero, Sergio,Molina, Alba
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supporting information
p. 5050 - 5053
(2020/05/18)
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- Enantioselective synthesis of α-secondary and α-tertiary piperazin-2- Ones and piperazines by catalytic asymmetric allylic alkylation
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The asymmetric palladium-catalyzed decarboxylative allylic alkylation of differentially N-protected piperazin-2- ones allows the synthesis of a variety of highly enantioenriched tertiary piperazine-2-ones. Deprotection and reduction affords the corresponding tertiary piperazines, which can be employed for the synthesis of medicinally important analogues. The introduction of these chiral tertiary piperazines resulted in imatinib analogues which exhibited comparable antiproliferative activity to that of their corresponding imatinib counterparts.
- Korch, Katerina M.,Eidamshaus, Christian,Behenna, Douglas C.,Stoltz, Brian M.,Nam, Sangkil,Horne, David
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supporting information
p. 179 - 183
(2015/02/05)
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- Method for Preparation of Piperazindione Derivatives
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A process for preparing piperazinedione derivatives of the formula I in which R1 is hydrogen, alkyl, alkenyl, alkynyl and alkylcarbonyl,R2 is hydrogen, alkyl, alkenyl, C3-C4-alkynyl and C(═O)R11,Rsup
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Page/Page column 7
(2011/06/26)
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- Influence of ring substitution on the conformation and β-turn mimicry of 4-amino-1,2,4,5-tetrahydro-2-benzazepin-3-one peptide mimetics
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Analogs of 4-amino-1,2,4,5-tetrahydro-2-benzazepin-3-ones, containing a methyl substituent at the 4- or 5-position, or a phenyl substituent at C-1, were prepared. Conformational analysis of tetrapeptide models containing these analogs indicated different
- De Wachter, Rien,Brans, Luc,Ballet, Steven,Van den Eynde, Isabelle,Feytens, Debby,Keresztes, Attila,Toth, Geza,Urbanczyk-Lipkowska, Zofia,Tourwé, Dirk
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experimental part
p. 2266 - 2278
(2009/08/08)
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- Phosphorus-containing aminocarboxylic acids: XIV. Synthesis of analogs of α-substituted glutamic acid
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Addition of Schiff bases derived from amino acid esters to appropriate vinylphosphoryl compounds, followed by hydrolysis of the adducts formed gives a series of new α-alkylated phosphorus-containing α-aminocarboxylic acids, viz. phosphonic and phosphinic
- Saratovskikh,Ragulin
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p. 1077 - 1084
(2007/10/03)
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- A Concise Synthesis of Sterically Hindered 3-Amino-2-Oxindoles
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A new method for the synthesis of 3-alkyl-3-amino-2-oxindoles is reported. These compounds are prepared in a 3-step procedure using a base-mediated nucleophilic addition of benzylidene-imine protected α-aminoesters to 2-nitrofluorobenzene as the key step. The process provides a variety of 3-alkyl-3-amino-2-oxindole analogs in yields of 1-24%. Yields are highest with alanine, phenylalanine and 2-pyridylalanine as the amino acid starting materials, while 3-pyridylalanine and O-methyltyrosine are less efficiently arylated. Sterically hindered amino acids such as valine and phenylglycine are for all practical purposes, not substrates for the key nucleophilic substitution reaction. The resulting 3-alkyl-3-amino-2-oxindoles are important intermediates for the preparation of drug-like substances. The conversion of alanine ethyl ester to 3-amino-3-methyl-2-oxindole is described.
- O'Connor, Stephen J.,Liu, Zheng
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p. 2135 - 2138
(2007/10/03)
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