title: Unprecedented biomimetic homodimerization of oroidin and clathrodin marine metabolites in the presence of HMPA or phosphonate salt tweezers.
abstract: The first biomimetic homodimerization of oroidin and clathrodin was effected in the presence HMPA and diphosphonate salts, strong guanidinium and amide chelating agents. The intermolecular associations probably interfere with the entropically and kinetically favored intramolecular cyclizations. Use of oroidin·(1)/2HCl salt or clathrodin·(1)/2HCl was indicative in the presence of the ambident nucleophilic and electrophilic tautomers of the 2-aminoimidazolic oroidin and clathrodin precursors. Surprisingly, the homodimerization of oroidin led to the nagelamide D skeleton, while the homodimerization of clathrodin gave the benzene para-symmetrical structure 19. The common process was rationalized from tautomeric precursors I and III.
authors: Institut de Chimie des Substances Naturelles, UPR 2301, Centre de Recherches de Gif-sur-Yvette, Avenue de la Terrasse, Gif-sur-Yvette, France.
authors: Clarisse
authors: C
authors: Lejeune
authors: Hua
authors: H
authors: Tian
authors: Jérôme
authors: J
authors: Appenzeller
authors: Ludmila
authors: L
authors: Ermolenko
authors: Marie-Thérèse
authors: MT
authors: Martin
authors: Ali
authors: A
authors: Al-Mourabit
mesh_terms: D003500:Cyclization; D006492:Hempa / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D008386:Marine Biology; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D011758:Pyrroles / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D007093:Imidazoles; D011758:Pyrroles; C540090:nagelamide D; C077211:clathrodin; D006492:Hempa; C077209:oroidin