Here we report a versatile ring-closing metathesis-based approach to 5-, 6-, and 7-membered cyclic beta-amino esters starting with simple and readily available building blocks-methionine, allylglycine, and serine-where the nature of the amino acid determines the size of the carbocyclic ring.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/jo049794g | DOI Listing |
Beilstein J Org Chem
December 2024
UMR 8076, BioCIS, CNRS, Université Paris-Saclay, avenue des sciences, 91400 Orsay, France.
The synthesis of tripeptides incorporating new fluorinated heterocyclic hydrazino acids, based on the tetrahydropyridazine scaffold is described. Starting from simple fluorinated hydrazones, these non-proteinogenic cyclic β-amino acids were easily prepared by a zinc-catalyzed aza-Barbier reaction followed by an intramolecular Michael addition. Preliminary conformational studies on tripeptides including this scaffold in the central position show an extended conformation in solution (NMR) and in the solid state (X-ray).
View Article and Find Full Text PDFOrg Lett
December 2024
Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science & Technology, Shanghai 200237, China.
Highly enantioselective allylic amination and alkylation of racemic sterically hindered aryl-substituted Morita-Baylis-Hillman (MBH) adducts have been achieved by using an in situ formed Pd-catalyst from an axially chiral phenanthroline ligand. This dynamic kinetic asymmetric transformation (DYKAT) is compatible with cyclic and acyclic secondary amines, dialkyl malonates, β-keto esters, acetylacetone, and malononitrile, affording the corresponding chiral products, such as β-amino acid esters, in up to 95% yield and with up to a 99:1 enantiomeric ratio.
View Article and Find Full Text PDFSci Rep
October 2024
Department of Chemistry, Materials, and Chemical Engineering "G. Natta", Politecnico di Milano, via Mancinelli 7, 20131, Milan, Italy.
Angew Chem Int Ed Engl
August 2024
Institute of Chemistry, The Center for Nanoscience and Nanotechnology, Casali Center of Applied Chemistry, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel.
J Org Chem
July 2024
Department of Chemistry, UNC College of Arts and Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States.
Bifunctional thiourea-based organocatalysts facilitate an enantioselective desymmetrization and Lossen rearrangement cascade reaction of -sulfoxy -succinimides, resulting in the synthesis of cyclic β-amino acid derivatives. This catalytic system was optimized for bicyclic and tricyclic succinimide substrates affording yields from 61-91% and up to 96:4 er. This reaction proceeds via the group selective addition of the primary alcohol nucleophile to an enantiotopic carbonyl group with sequential rearrangement of the intermediate -sulfonyl hydroxamate ester.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!