title: Structural studies of β-turn-containing peptide catalysts for atroposelective quinazolinone bromination.
abstract: We describe herein a crystallographic and NMR study of the secondary structural attributes of a β-turn-containing tetra-peptide, Boc-Dmaa-D-Pro-Acpc-Leu-NMe2, which was recently reported as a highly effective catalyst in the atroposelective bromination of 3-arylquinazolin-4(3H)-ones. Inquiries pertaining to the functional consequences of residue substitutions led to the discovery of a more selective catalyst, Boc-Dmaa-D-Pro-Acpc-Leu-OMe, the structure of which was also explored. This new lead catalyst was found to exhibit a type I'β-turn secondary structure both in the solid state and in solution, a structure that was shown to be an accessible conformation of the previously reported catalyst, as well.
authors.affiliation: Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA. scott.miller@yale.edu.
authors.forename: A J
authors.initials: AJ
authors.lastname: Metrano
authors.forename: N C
authors.initials: NC
authors.lastname: Abascal
authors.forename: B Q
authors.initials: BQ
authors.lastname: Mercado
authors.forename: E K
authors.initials: EK
authors.lastname: Paulson
authors.forename: S J
authors.initials: SJ
authors.lastname: Miller
mesh_terms: D001966:Bromine / Q000737:chemistry*; D002384:Catalysis; D018360:Crystallography, X-Ray; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D011799:Quinazolines / Q000737:chemistry*
chemical_list: D010455:Peptides; D011799:Quinazolines; D001966:Bromine