Highly efficient alkene epoxidation and aziridination catalyzed by iron(II) salt + 4,4',4'-trichloro-2,2':6',2'-terpyridine/4,4'-dichloro-4'-O-PEG-OCH3-2,2':6',2'-terpyridine

"Iron(II) salt + 4,4',4'-trichloro-2,2':6',2'-terpyridine" is an effective catalyst for epoxidation and aziridination of alkenes and intramolecular amidation of sulfamate esters. The epoxidation of allylic-substituted cycloalkenes achieved excellent diastereoselectivities up to 90%. ESI-MS results supported the formation of iron-oxo and -imido intermediates. Derivitization of Cl 3terpy to O-PEG-OCH 3-Cl 2terpy renders the terpyridine unit to be recyclable, and the "iron(II) salt + 4,4'-dichloro-4'- O-PEG-OCH 3-2,2':6',2'-terpyridine" protocol can be reused without a significant loss of catalytic activity in the alkene epoxidation.     

Facile synthesis and platinum complexes of 4',5,5'-trisubstituted-2,2':6',2'-terpyridines

The synthesis of trisubstituted 4',5,5' terpyridines is described. The strategy begins with synthesis of 2-acetyl-5-bromopyridine (3) from 2,5-dibromopyridine, substitution of the bromine in 3 using a variety of metal-catalyzed reactions and then formation of the terpyridine using the Krohnke reaction. The complexes have been prepared by reaction of [Pt(PhCN)(2)Cl(2)] with the appropriate silver salt followed by addition of the terpyridyl ligand. The crystal structure of two complexes have been determined via X-ray diffraction and the MLCT (metal-to-ligand charge-transfer) emissions determined by UV/Vis spectroscopy.