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Scalable synthesis and coupling of quaternary α-arylated amino acids: α-aryl substituents are tolerated in α-helical peptides.

ABSTRACT: Quaternary amino acids are important tools for the modification and stabilisation of peptide secondary structures. Here we describe a practical and scalable synthesis applicable to quaternary alpha-arylated amino acids (Q4As), and the development of solid-phase synthesis conditions for their incorporation into peptides. Monomeric and dimeric α-helical peptides are synthesised with varying degrees of Q4A substitution and their structures examined using biophysical methods. Both enantiomers of the Q4As are tolerated in folded monomeric and oligomeric α-helical peptides, with the (R)-enantiomer slightly more so than the (S).

SUBMITTER: Leonard DJ

PROVIDER: S-EPMC8278958 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Organocatalytic asymmetric formal oxidative coupling for the construction of all-aryl quaternary stereocenters.

Project description:A new catalytic asymmetric formal cross dehydrogenative coupling process for the construction of all-aryl quaternary stereocenters is disclosed, which provides access to rarely explored chiral tetraarylmethanes with excellent enantioselectivity. The suitable oxidation conditions and the hydrogen-bond-based organocatalysis have enabled efficient intermolecular C-C bond formation in an overwhelmingly crowded environment under mild conditions. para-Quinone methides bearing an ortho-directing group serve as the key intermediate. The precise loading of DDQ is critical to the high enantioselectivity. The chiral products have also been demonstrated as promising antiviral agents.

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Inhibition of FOXP3 by Stapled Alpha-Helical Peptides Dampens Regulatory T Cell Function

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2022-09-29 | GSE201116 | GEO

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