203252-08-8Relevant academic research and scientific papers
Derivatives and application to the asymmetric synthesis of unnatural α-amino acid derivative
Inokuma, Tsubasa,Jichu, Takahisa,Nishida, Kodai,Shigenaga, Akira,Otaka, Akira
, p. 573 - 581 (2017/06/07)
We describe herein a manganese(IV) oxide-mediated oxidation of N-p-methoxyphenyl (PMP)-protected glycine derivatives for the synthesis of a-imino carboxylic acid derivatives. Using this methodology, utilization of unstable glyoxic acid derivatives was avoided. Furthermore, using this methodology we synthesized novel a-imino carboxylic acid derivatives such as a-imino phenyl ester, perfluoroalkyl etsers, imides, and thioester. The asymmetric Mannich reaction of those novel imine derivatives with 1,3-dicarbonyl compound is also described, and the novel a-imino imide gave improved chemical yield and stereoselectivity compared with those obtained by the use of the conventional a-imino ester-type substrate.
A convenient method for preparation of α-imino carboxylic acid derivatives and application to the asymmetric synthesis of unnatural α-amino acid derivative
Inokuma, Tsubasa,Jichu, Takahisa,Nishida, Kodai,Shigenaga, Akira,Otaka, Akira
, p. 573 - 581 (2019/12/26)
We describe herein a manganese(IV) oxide-mediated oxidation of N-p-methoxyphenyl (PMP)-protected glycine derivatives for the synthesis of α-imino carboxylic acid derivatives. Using this methodology, utilization of unstable glyoxic acid derivatives was avo
TRANS-3,5-DISUBSTITUTEDPYRROLIDINE: ORGANOCATALYST FOR anti-MANNICH REACTIONS
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Page/Page column 27, (2010/11/27)
A compound of Formula I is disclosed, in which R is a substituent containing a hydrogen bond-forming atom within three atoms from the ring carbon to which the substituent is bonded; X is CH2, O, S or NR1, wherein R1 is a hydrocarbyl group or an amino-protecting group having one to about 18 carbon atoms; R2 is hydrido or a hydrocarbyl group containing one to about twelve carbon atoms; and R3 is hydrido or methyl, but both R2 and R3 are not hydrido when X is CH2 A molecule of Formula I and those in which R2 and R3 can both be hydrido (Formula X) functions as a catalyst in a Mannich reaction to asymmetrically form β-aminoaldehyde or β-aminoketone diastereomeric products having two chiral centers on adjacent carbon atoms and in which the anti-diastereomers are in excess over the syn-diastereomers. Methods for carrying out those syntheses are also disclosed.
3-Pyrrolidinecarboxylic acid for direct catalytic asymmetric anti-Mannich-type reactions of unmodified ketones
Zhang, Haile,Mifsud, Maria,Tanaka, Fujie,Barbas III, Carlos F.
, p. 9630 - 9631 (2007/10/03)
We report the development of direct catalytic, enantioselective, anti-selective Mannich-type reactions between unmodified ketones and α-imino esters under mild conditions. The reactions were performed using 5-10 mol % of (R)-3-pyrrolidinecarboxylic or (R)-β-proline as catalyst in an environmentally benign solvent, 2-PrOH, at room temperature. The anti-Mannich products were obtained in good yields with high diastereo- and enantioselectivities (up to anti/syn >99:1, 99% ee). While (3R,5R)-5-methyl-3-pyrrolidinecarboxylic acid is an excellent catalyst for the anti-Mannich-type reactions of aldehydes, it did not efficiently catalyze the corresponding Mannich-type reactions of ketones; (R)-3-pyrrolidinecarboxylic acid did efficiently catalyze the Mannich-type reactions of ketones. (S)-Proline or (S)-2-pyrrolidinecarboxylic acid has been reported to catalyze the Mannich-type reactions of ketones to afford the syn-products. Thus, the position of the carboxylic acid group on the pyrrolidine ring directs the stereoselection of the catalyzed reaction, providing either syn- or anti-Mannich products. Copyright
