217446-25-8Relevant academic research and scientific papers
A step-economic and one-pot access to chiral Cα-tetrasubstituted α-amino acid derivatives: Via a bicyclic imidazole-catalyzed direct enantioselective C -acylation
Wang, Mo,Zhang, Lu,Zhang, Wanbin,Zhang, Zhenfeng,Zhou, Muxing
, p. 4801 - 4807 (2020/06/18)
Cα-Tetrasubstituted α-amino acids are ubiquitous and unique structural units in bioactive natural products and pharmaceutical compounds. The asymmetric synthesis of these molecules has attracted a lot of attention, but a more efficient method is still greatly desired. Here we describe the first sequential four-step acylation reaction for the efficient synthesis of chiral Cα-tetrasubstituted α-amino acid derivatives from simple N-acylated amino acids via an auto-tandem catalysis using a single nucleophilic catalyst. The synthetic efficiency is improved via a direct enantioselective C-acylation; the methodology affords the corresponding Cα-tetrasubstituted α-amino acid derivatives with excellent enantioselectivities (up to 99% ee). This step-economic, one-pot, and auto-tandem strategy provides facile access to important chiral building blocks, such as peptides, serines, and oxazolines, which are often used in medicinal and synthetic chemistry.
Chiral bicycle imidazole nucleophilic catalysts: Rational design, facile synthesis, and successful application in asymmetric Steglich rearrangement
Zhang, Zhenfeng,Xie, Fang,Jia, Jia,Zhang, Wanbin
supporting information; experimental part, p. 15939 - 15941 (2011/01/11)
A new type of chiral bicycle imidazole nucleophilic catalyst was rationally designed, facilely synthesized, and successfully applied in an asymmetric Steglich rearrangement with good to excellent yield and enantioselectivity at ambient temperature. Moreov
Metal complexes-catalyzed hydrolysis and alcoholysis of organic substrates and their application to kinetic resolution
Tokunaga, Makoto,Aoyama, Hiroshi,Kiyosu, Junya,Shirogane, Yuki,Iwasawa, Tetsuo,Obora, Yasushi,Tsuji, Yasushi
, p. 472 - 480 (2008/02/06)
Metal complexes-catalyzed hydrolysis and alcoholysis of organic substrates such as alkenyl esters, alkenyl ethers, and azlactones (oxazol-5(4H)-ones) are described. These reactions were applied for kinetic resolution of chiral compounds and high selectivities were achieved with vinyl ethers of 2-substituted cyclohexanols, 1,1′-bi-2-naphthols, 1,1′-bi-2-phenols, and 4,4-disubstituted azlactones. Oxidative carbon-carbon bond cleavage reactions, which were found in the course of the study of asymmetric hydrolysis were also described.
Kinetic resolution displaying zeroth order dependence on substrate consumption: Copper-catalyzed asymmetric alcoholysis of azlactones
Tokunaga, Makoto,Kiyosu, Junya,Obora, Yasushi,Tsuji, Yasushi
, p. 4481 - 4486 (2007/10/03)
Kinetic resolution of 4-alkyl-2-aryl-5-oxo-4,5-dihydrooxazole-4-carboxylic acid esters (azlactones 1) were achieved by copper-DTBM-SEGPHOS catalyzed alcoholysis reaction with good selectivity (12 examples). Variation of ee of unreacted substrates 1 and pr
