Iron(III) complexes of chiral bipyridine macrocycles as novel metallo-catalysts

Abstract

We have prepared a novel series of chiral macrocycles based on amino acid-linked bipyridines; the iron(iii) complexes of these ligands act as catalysts for alkene epoxidation.The remarkable stereoselectivity of many metalloenzymecatalysed reactions is due, in large part, to the chiral environment surrounding the metal. Synthetic macrocyclic ligands offer an attractive way of holding chiral groups in similar proximity to a metal centre in such a way that they can interact with an approaching substrate.' In designing potential

Amino Acid Derived Macrocycles—An Area Driven by Synthesis or Application?

“…An iron( III ) complex of chiral macrocycle 39 (Scheme ) was shown to catalyze the conversion of alkenes into the corresponding epoxides in the presence of iodosylbenzene as terminal oxidant 34. Cyclooctene gave exclusively epoxidized product in a reasonable yield (relative to iodosylbenzene amount employed), whereas styrene produced its epoxide and benzaldehyde.…”

Aminosäurehaltige Makrocyclen – anwendungsnahe Systeme oder nur Syntheseziele?

“…Ein Eisen( III )‐Komplex des chiralen Makrocyclus 39 (Schema ) katalysiert die Umwandlung von Alkenen in die entsprechenden Epoxide mit Iodosylbenzol als Oxidans 34. Von Cycloocten wurde in zufrieden stellender Ausbeute (bezogen auf Iodosylbenzol) ausschließlich das Epoxidierungsprodukt erhalten, wohingegen aus Styrol neben dem Epoxid auch Benzaldehyd entstand.…”

Amino-ether macrocycle that forms CuII templated threaded heteroleptic complexes: a detailed selectivity, structural and theoretical investigations

“…1 In recent times, organic macrocyclic ligands with centrally directed metal ion binding sites such as pyridyl ring, 2 imine, 3 amine, 4 sulfide, 5 phosphine, 6 oxy ether, 7 azacrown ether 8 , etc. have shown potential application in the areas of recognition, 9 sensing, 4,10 catalysis, 11 self-assemblies 7b,12 and so on. Moreover, heteroleptic metal complexes by using such macrocyclic metal ion complexes have been successfully utilized for the development of interlocked molecular systems like pseudorotaxanes, 13 rotaxanes 1c,13c,14 and catenanes.…”