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

• Type: Article in International Scientific Journal
• Date: 2008

Authors

Jimenez Oses, G (Author) Other; Garcia, JI (Author) Other; Silva, AMG (Author) Other; Santos, ARN (Author) Other; Tome, AC (Author) Other; Neves, MGPMS (Author) Other; Cavaleiro, JAS (Author) Other

Journal

Title: Tetrahedron

Vol. 64

Pages: 7937-7943

ISSN: 0040-4020

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 29 Citations

Scopus - 31 Citations

Other information

Authenticus ID: P-003-WZC

DOI: 10.1016/j.tet.2008.06.018

Abstract (EN): 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7