Article

Photoinduced-electron-transfer chemistry: from studies on PET processes to applications in natural product synthesis.

Institute of Organic Chemistry, University of Cologne, Greinstr. 4, 50939 Köln, Germany.
Accounts of Chemical Research (Impact Factor: 24.35). 03/2007; 40(2):128-40. DOI: 10.1021/ar068148w
Source: PubMed

ABSTRACT The application of photoinduced electron transfer (PET) for the construction of heterocyclic ring systems is an appealing route in synthetic organic photochemistry. Electronically excited carbonyl chromophors in ketones, aldehydes, amides, or imides are strong electron acceptors that oxidize alkenes, amines, thioethers, or carboxylates. In subsequent steps, the radical anions formed thereof either are operating as secondary electron donors and initiate a photon-driven chain reaction or combine with electrophilic species and form products. These reactions are applied in the synthesis of heterocyclic compounds. The basic structures of these target molecules are bicyclic tertiary amines from the pyrrolizidine, benzopyrrolizidine, and indolizidine families, cyclic oligopeptides, macrocyclic ring systems, and many more.

0 Bookmarks
 · 
150 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The whole mol-ecule of the title compound, C17H10N4O5·2H2O, is generated by twofold rotation symmetry and it crystallized as a dihydrate. The planes of the phthalimide moieties and the urea unit are almost normal to one another, with a dihedral angle of 78.62 (9)°. In the crystal, mol-ecules are linked by N-H⋯O and O-H⋯O hydrogen bonds, forming a three-dimensional framework structure. The crystal packing also features C-H⋯O hydrogen bonds and slipped parallel π-π inter-actions [centroid-centroid distance = 3.6746 (15) Å] involving the benzene rings of neighbouring phthalimide moieties.
    Acta Crystallographica Section E Structure Reports Online 11/2014; 70(Pt 11):373-375. DOI:10.1107/S1600536814022144 · 0.35 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Tertiary anilines can be prompted to react with N‐aryl‐ and N‐benzylmaleimides to form tetrahydroquinoline products under photocatalysis using visible light irradiation, the ruthenium or iridium complexes Ru(bpy)3Cl2 or Ir(ppy)2(dtbbpy)PF6 as catalyst, and air as terminal oxidant.
    Advanced Synthesis & Catalysis 12/2012; 354(18). DOI:10.1002/adsc.201200608 · 5.54 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Employing nanosecond laser flash photolysis, we have determined the relative importance of two fragmentation modes, namely, C-C bond cleavage and deprotonation, for the radical-cation of 1,1,2,2-tetraphenyl ethane photogenerated by electron transfer to cyanoaromatic singlet excited states in acetonitrile at room temperature. An analysis of the kinetic data for this phenyl alkane suggests that the C-C bond cleavage dominates over the deprotonation by a ratio of about 2:1. In addition, the deprotonation kinetics of diphenyl methane, 1,1-diphenyl ethane, triphenyl methane and several phenyl-substituted alcohols have been investigated. To aid identification and characterization, experiments based on two laser pulses in tandem (308 and 337.1 nm) were performed to probe the fluorescence and photochemistry of transient radicals formed as products of radical ion fragmentation. The first-order rate constants for growth of transient absorptions due to fragmentation-derived radicals were measured to be  1×106 s-1. Activation parameters, with activation enthalpies in the range 10-18 kJ/mol and activation entropies between -60 and -91 J/(mol.K), are also reported for fragmentation kinetics of radical cations of several systems under study.
    The Journal of Physical Chemistry A 10/2014; 118(47). DOI:10.1021/jp508556z · 2.78 Impact Factor

Full-text

Download
183 Downloads
Available from
May 20, 2014