Unprecedented Double aza-Michael Addition within a Sapphyrin Core

作者：Figueira Flavio; Marques Igor; Farinha Andreia S F; Tome Augusto C; Cavaleiro Jose A S; Silva Artur M S; Sessler Jonathan; Felix Vitor^*; Tome Joao P C^*

来源：Chemistry - A European Journal, 2016, 22(40): 14349-14355.

DOI：10.1002/chem.201602313

• anions
• cycloaddition
• density functional calculations
• Michael addition
• porphyrinoids

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.

• 出版日期2016-9