Mechanistic insights on the site selectivity in successive 1,3-dipolar cycloadditions to meso-tetraarylporphyrins

  1. Jiménez-Osés, G. 2
  2. García, J.I. 2
  3. Silva, A.M.G. 1
  4. Santos, A.R.N. 1
  5. Tomé, A.C. 1
  6. Neves, M.G.P.M.S. 1
  7. Cavaleiro, J.A.S. 1
  1. 1 Universidade de Aveiro
    info

    Universidade de Aveiro

    Aveiro, Portugal

    ROR https://ror.org/00nt41z93

  2. 2 Instituto de Nanociencia y Materiales de Aragón
    info

    Instituto de Nanociencia y Materiales de Aragón

    Zaragoza, España

    ROR https://ror.org/031n2c920

Revista:
Tetrahedron

ISSN: 0040-4020

Año de publicación: 2008

Volumen: 64

Número: 34

Páginas: 7937-7943

Tipo: Artículo

DOI: 10.1016/J.TET.2008.06.018 SCOPUS: 2-s2.0-46649104723 WoS: WOS:000258271300011 GOOGLE SCHOLAR

Otras publicaciones en: Tetrahedron

Resumen

A DFT study on site selectivity in successive 1,3-dipolar cycloadditions of meso-tetraarylporphyrins with azomethine ylide and N-methylnitrone has been carried out. The calculation of the thermodynamic stability of both ylide and nitrone-derived adducts reveals that bacteriochlorins are more stable and have stronger aromatic character than isobacteriochlorins. Calculations of whole reaction pathways show that cycloadditions of azomethine ylide on porphyrin and its derived chlorin are irreversible and hence kinetically controlled. Solvent influence on the site selectivity of this reaction has also been considered, and appears to be decisive in controlling the site selectivity. In contrast, cycloadditions of nitrone over porphyrin and chlorin are clearly reversible, pointing to a thermodynamic control of these reactions. © 2008 Elsevier Ltd. All rights reserved.