Asymmetric PTC C-alkylation catalyzed by chiral derivatives of tartaric acid and aminophenols. Synthesis of (R)- and (S)-alpha-methyl amino acids

Belokon, Yuri N. and Kochetkov, Konstantin A. and Churkina, Tatiana D. and Ikonnikov, Nikolai S. and Chesnokov, Alexey A. and Larionov, Oleg V. and Singh, Ishwar and Parmar, Virinder S. and Vyskocil, Stepan and Kagan, Henri B. (2000) Asymmetric PTC C-alkylation catalyzed by chiral derivatives of tartaric acid and aminophenols. Synthesis of (R)- and (S)-alpha-methyl amino acids. Journal of Organic Chemistry, 65 (21). pp. 7041-7048. ISSN 0022-3263

Full content URL: http://dx.doi.org/10.1021/jo000719p

Full text not available from this repository.

Item Type:Article
Item Status:Live Archive

Abstract

A new type of efficient chiral catalyst has been elaborated for asymmetric C-alkylation of CH acids under PTC conditions. Sodium alkoxides formed from chiral derivatives of tartaric acid and aminophenols (TADDOL's 2a-e and NOBLN's 3a-h) can be used as chiral catalysts in the enantioselective alkylation, as exemplified by the reaction of Schiff's bases Pa-e derived from alanine esters and benzaldehydes with active alkyl halides. Acid-catalyzed hydrolysis of the products formed in the reaction afforded (R)-alpha -methylphenylalanine, (R)-alpha -naphthylmethylalanine, and (R)alpha -allylalanine in 61-93% yields and with ee 69-93%. The procedure could be successfully scaled up to 6 g of substrate 1b. When (S,S)-TADDOL or (R)-NOBIN are used, the (S)-amino acids are formed. A mechanism rationalizing the observed features of the reaction has been suggested.

Additional Information:Publication Date (Web): September 22, 2000
Keywords:Alkylation
Subjects:B Subjects allied to Medicine > B200 Pharmacology, Toxicology and Pharmacy
Divisions:College of Science > School of Pharmacy
ID Code:11315
Deposited On:24 Jul 2013 09:40

Repository Staff Only: item control page