title: Synthesis of rigid tryptophan mimetics by the diastereoselective Pictet-Spengler reaction of β³-homo-tryptophan derivatives with chiral α-amino aldehydes.
abstract: The Pictet-Spengler (PS) cyclizations of β(3)-hTrp derivatives as arylethylamine substrates were performed with L-α-amino and D-α-amino aldehydes as carbonyl components. During the PS reaction, a new stereogenic center was created, and the mixture of cis/trans 1,3-disubstituted 1,2,3,4-tetrahydro-β-carbolines was obtained. The ratio of cis/trans diastereomers depends on the stereogenic centre of used amino aldehyde and the size of substituents. It was confirmed by 1H and 2D NMR (ROESY) spectra. The conformations of cyclic products were studied by 2D NMR ROESY spectra. Products of the PS condensation after removal of protecting group(s) can be incorporated into a peptide chain as tryptophan mimetics with the possibility of the β-turn induction.
authors.affiliation: Faculty of Chemistry, University of Warsaw, Warsaw, Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Slupska
authors.affiliation: Faculty of Chemistry, University of Warsaw, Warsaw, Poland.
authors.forename: Karolina
authors.initials: K
authors.lastname: Pulka-Ziach
authors.affiliation: Faculty of Chemistry, University of Warsaw, Warsaw, Poland.
authors.forename: Edyta
authors.initials: E
authors.lastname: Deluga
authors.affiliation: Faculty of Chemistry, University of Warsaw, Warsaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Sosnowski
authors.affiliation: Faculty of Chemistry, University of Warsaw, Warsaw, Poland.
authors.forename: Beata
authors.initials: B
authors.lastname: Wilenska
authors.affiliation: Faculty of Chemistry, University of Warsaw, Warsaw, Poland.
authors.forename: Wiktor
authors.initials: W
authors.lastname: Kozminski
authors.affiliation: Faculty of Chemistry, University of Warsaw, Warsaw, Poland.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Misicka
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D040761:Biomimetic Materials / Q000138:chemical synthesis / Q000737:chemistry; D003500:Cyclization; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D015394:Molecular Structure; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D014364:Tryptophan / Q000737:chemistry*
chemical_list: D000447:Aldehydes; D010455:Peptides; D014364:Tryptophan
keywords: P-S cyclisation; beta-turn; building blocks; diastereoselectivity; tryptophan mimetics