Premium
Non‐Enzymatic Hybrid Catalysis for Stereoconversion of l ‐Amino Acid Derivatives to d ‐Isomers
Author(s) -
Nagato Yuya,
Kiyokawa Mari,
Ueki Yusuke,
Kikuchi Jun,
Ohmatsu Kohsuke,
Terada Masahiro,
Ooi Takashi
Publication year - 2020
Publication title -
asian journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.846
H-Index - 44
eISSN - 2193-5815
pISSN - 2193-5807
DOI - 10.1002/ajoc.202000067
Subject(s) - chemistry , racemization , kinetic resolution , catalysis , amino acid , aldehyde , enantiomer , lewis acids and bases , brønsted–lowry acid–base theory , organic chemistry , phosphoric acid , chirality (physics) , enantioselective synthesis , enantiomeric excess , palladium , combinatorial chemistry , biochemistry , chiral symmetry breaking , physics , quantum mechanics , quark , nambu–jona lasinio model
A catalytic transformation of N ‐unprotected l ‐amino esters to N ‐protected d ‐amino esters was developed. The combined use of a heteroaromatic aldehyde, Lewis acid, palladium complex, and chiral Brønsted acid was a key factor for the successful operation of this catalytic system. The synergistic cooperation of an appropriate aldehyde and Lewis acid was crucial for promoting an efficient racemization of l ‐amino esters, while the combination of a palladium complex and chiral phosphoric acid enabled dynamic kinetic resolution through asymmetric N‐allylation, providing N ‐protected d ‐amino esters in good yields with up to 97 : 3 er. Following appropriate deprotection processes, d ‐amino acids were obtained without loss of enantiomeric purity.