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Unprecedented Double aza‐Michael Addition within a Sapphyrin Core
Author(s) -
Figueira Flávio,
Marques Igor,
Farinha Andreia S. F.,
Tomé Augusto C.,
Cavaleiro José A. S.,
Silva Artur M. S.,
Sessler Jonathan,
Félix Vítor,
Tomé João P. C.
Publication year - 2016
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201602313
Subject(s) - dimethyl acetylenedicarboxylate , acetylene , pyrrole , chemistry , molecule , derivative (finance) , stereochemistry , medicinal chemistry , organic chemistry , cycloaddition , financial economics , economics , catalysis
A novel sapphyrin derivative was obtained from the reaction between a free‐base sapphyrin and dimethyl acetylenedicarboxylate (DMAD). The formation of the new compound involved a double aza‐Michael addition of two pyrrolic NH groups to a DMAD molecule, with the formation of a disubstituted ethano bridge. The NMR spectral data reveal a product with an unsymmetrical structure; DFT calculations provided support for a structure in which the ethano bridge links two adjacent pyrrole units. The present study provides a seemingly unprecedented example of an N , N′ ‐dinucleophile reacting with DMAD to form a heterocyclic compound in which the two N‐atoms are linked to the two sp 3 carbon atoms derived from a substituted acetylene.