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Search for "chiral carboxylic acids" in Full Text gives 6 result(s) in Beilstein Journal of Organic Chemistry.
Diastereoselective Ugi reaction of chiral 1,3-aminoalcohols derived from an organocatalytic Mannich reaction
Beilstein J. Org. Chem. 2016, 12, 139–143, doi:10.3762/bjoc.12.15
- simpler variants) [10][11][12]. On the other hand, diastereoselective reactions using at least one chiral component are troublesome. Chiral isocyanides and chiral carboxylic acids invariably afford nearly 1:1 mixtures. α-Chiral aldehydes have a high tendency to racemize/epimerize [13][14] and additionally
Isocyanide-based multicomponent reactions towards cyclic constrained peptidomimetics
Beilstein J. Org. Chem. 2014, 10, 544–598, doi:10.3762/bjoc.10.50
The Flögel-three-component reaction with dicarboxylic acids – an approach to bis(β-alkoxy-β-ketoenamides) for the synthesis of complex pyridine and pyrimidine derivatives
Beilstein J. Org. Chem. 2014, 10, 394–404, doi:10.3762/bjoc.10.37
- investigations revealed that this method tolerates a broad variety of differently substituted starting materials – inter alia (het-)aromatic and (branched) aliphatic nitriles and carboxylic acids. It is also noteworthy to mention that the configurational integrity of enantiopure α-chiral carboxylic acids and/or
Non-cross-linked polystyrene-supported 2-imidazolidinone chiral auxiliary: synthesis and application in asymmetric alkylation reactions
Beilstein J. Org. Chem. 2013, 9, 2113–2119, doi:10.3762/bjoc.9.248
- auxiliaries; chiral carboxylic acids; 2-imidazolidinone; non-cross-linked polystyrene; Introduction Chiral auxiliaries have been proven as a powerful tool for the asymmetric synthesis of highly optical pure compounds used in pharmaceuticals or agrochemicals [1][2]. The recycling and reuse of expensive chiral
- for asymmetric synthesis, into the solid support [18][19]. As a part of our ongoing research, we herein report a novel NCPS-supported 2-imidazolidinone chiral auxiliary that exhibited excellent diastereocontrol. Its recycling and reuse for the synthesis of several chiral carboxylic acids are addressed
Enantioselective reduction of ketoimines promoted by easily available (S)-proline derivatives
Beilstein J. Org. Chem. 2013, 9, 633–640, doi:10.3762/bjoc.9.71
- successful catalyst is not an easily available compound and, in that work, no examples of carbon–nitrogen double-bond reduction were described. Results and Discussion In our approach we decided to investigate very simple chiral carboxylic acids, and we turned our attention to the most obvious source of
A practical two-step procedure for the preparation of enantiopure pyridines: Multicomponent reactions of alkoxyallenes, nitriles and carboxylic acids followed by a cyclocondensation reaction
Beilstein J. Org. Chem. 2011, 7, 962–975, doi:10.3762/bjoc.7.108
- enantiopurity [40]. Chiral carboxylic acids are readily available and their use would allow for a rapid access to pyridines with side chains bearing stereogenic centers. In recent years we studied intensively the multicomponent reactions of lithiated alkoxyallenes with nitriles and carboxylic acids and could
- carboxylic acids, enantiopure nitriles were also successfully converted into pyridine derivatives in comparable yields. As an example, (S)-2-methylbutyronitrile (31) could be converted into compound 40 in good yield. The use of carboxylic acids and nitriles with structurally identical substituents allows a
- -dibenzylated amino acids, such as those derived from valine and phenylalanine, 23 and 25 gave the respective pyridines 24 and 26 in 45% and 50% yield, respectively. Carboxylic acids featuring aromatic units and branched side chains including quaternary α-carbon atoms were also tolerated. Besides chiral
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