ABSTRACT
A series of novel isoindolone derivatives (13-18) were prepared in goods yields by applying the TAWERS methodology. A general approach for formation of isoindolones from the aza-Wittig reaction of iminophosphoranes with dialdehydes under neutral and mild conditions was realized. Using 1D NMR a [1,3]-hydride migration was detected. The assignment of the structures and conformation behavior of the derivatives was achieved using 1D and 2D NMR (NOESY, DEPT, HMQC, and HMBC).
Subject(s)
Indoles/chemistry , Indoles/chemical synthesis , Isomerism , Magnetic Resonance Spectroscopy , Molecular Structure , ProtonsABSTRACT
Using per(3,6-anhydro)cyclodextrin derivatives [per(3,6-anhydro)CD], it was possible to produce new lanthanide chelates by careful choice of the size and functional groups. Heptakis(3,6-anhydro-2-O-methyl)cyclomaltoheptaose fulfils the best criteria for complexation of lanthanide ions. Nuclear magnetic resonance was used to derive the association constants and the stoichiometries of these new complexes. Finally, a three-dimensional structure of these complexes consistent with the NMR data is proposed, to ascertain the position of lanthanide in the cavity of the per(3,6-anhydro)CD. For the present purposes, heptakis(2-O-acetyl-3,6-anhydro)cyclomaltoheptaose, octakis(2-O-acetyl-3,6-anhydro)cyclomaltooctaose, heptakis(3,6-anhydro-2-O-methyl)cyclomaltoheptaose and octakis(3,6-anhydro-2-O-methyl)cyclomaltooctaose have been synthesized and purified.