Premium
Tripeptides of the Type H‐ D ‐Pro‐Pro‐Xaa‐NH 2 as Catalysts for Asymmetric 1,4‐Addition Reactions: Structural Requirements for High Catalytic Efficiency
Author(s) -
Wiesner Markus,
Neuburger Markus,
Wennemers Helma
Publication year - 2009
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200901021
Subject(s) - catalysis , tripeptide , chemistry , amide , stereoselectivity , conjugate , peptide , stereochemistry , amino acid , combinatorial chemistry , structural motif , catalytic efficiency , enantioselective synthesis , organic chemistry , biochemistry , mathematical analysis , mathematics
Analysis of the structural and functional requirements within the asymmetric peptidic catalyst H‐ D ‐Pro‐Pro‐Asp‐NH 2 led to the development of the closely related peptide H‐ D ‐Pro‐Pro‐Glu‐NH 2 as an even more efficient catalyst for asymmetric conjugate addition reactions of aldehydes to nitroolefins. In the presence of as little as 1 mol % of H‐ D ‐Pro‐Pro‐Glu‐NH 2 , a broad range of aldehydes and nitroolefins react readily with each other. The resulting γ‐nitroaldehydes were obtained in excellent yields and stereoselectivities at room temperature. Within the structure of the peptidic catalysts, the D ‐Pro‐Pro motif is the major contributor to the high stereoselectivities. The C‐terminal amide and the spacer to the carboxylic acid in the side‐chain of the C‐terminal amino acid are responsible for the fine‐tuning of the stereoselectivity. The peptidic catalysts not only allow for highly effective asymmetric catalysis under mild conditions, but also function in the absence of additives.