Catalytic hydrogenation of meso-octamethylporphyrinogen (calix[4]pyrrole).
Hydrogenation of meso-octamethylporphyrinogen (calix[4]pyrrole) with a number of heterogeneous catalysts under different experimental conditions has been investigated. GC-MS analyses of the reaction mixtures showed the formation of one to four products in low to moderate yields: three of them were diastereoisomers of the product derived from half-hydrogenation of the substrate, and displayed alternating pyrrolidine and pyrrole rings, while the fourth was the all-cis saturated product. An acidic medium was necessary to achieve hydrogenation. However, the use of too strongly acidic solvents or additives was detrimental to the stability of the substrate and/or the catalyst.
Journot
Guillaume
G
Institut de Chimie, Université de Neuchâtel, Rue Emile-Argand 11, CP 158, 2009 Neuchâtel, Switzerland.
Letondor
Christophe
C
Neier
Reinhard
R
Stoeckli-Evans
Helen
H
Savoia
Diego
D
Gualandi
Andrea
A
D047250:Calixarenes / Q000737:chemistry*; D002384:Catalysis; D006865:Hydrogenation; D008958:Models, Molecular; D015394:Molecular Structure; D011166:Porphyrins / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D011759:Pyrrolidines / Q000737:chemistry*; D012995:Solubility; D012997:Solvents / Q000737:chemistry*; D013237:Stereoisomerism
D011166:Porphyrins; D011758:Pyrroles; D011759:Pyrrolidines; D012997:Solvents; C550820:meso-octamethylporphyrinogen(calix(4)pyrrole); D047250:Calixarenes; C032519:pyrrolidine