title: New chiral phosphoramidite complexes of iron as catalytic precursors in the oxidation of activated methylene groups.
abstract: New phosphoramidite complexes of iron were synthesized and structurally characterized. Reaction of the known chiral phosphoramidites (RO)2PNR'2 (R = binaphthyl, R' = CH3, 1a; R = binaphthyl, R' = benzyl, 1b) with [FeBr(Cp)(CO)2] afforded the title compounds [FeBr(Cp)(CO)(1a,b)] (4a,b) in 34 and 65 % isolated yields as mixtures of diastereomers, since both the metal and the ligand are stereogenic. Similarly, reaction of 1b with [Fe(Cp)I(CO)2] in the presence of catalytic [Fe(Cp)(CO)2]2 afforded [Fe(Cp)I(CO)(1b)] (5b) in 81% yield as a mixture of diastereomers. The molecular structures of 4a, 4b and 5 were determined, revealing a pseudo octahedral coordination geometry about the iron center. The new metal complexes are catalytically active in the oxidation of benzylic methylene groups to the corresponding ketones, utilizing t-BuOOH as oxidant (2 mol% catalyst, 36 h, room temperature, 31-80% yield).
authors.affiliation: University of Missouri - St. Louis, Department of Chemistry and Biochemistry, St. Louis, MO 63121, USA. pssgk8@umsl.edu
authors.forename: Pushkar
authors.initials: P
authors.lastname: Shejwalkar
authors.forename: Nigam P
authors.initials: NP
authors.lastname: Rath
authors.forename: Eike B
authors.initials: EB
authors.lastname: Bauer
mesh_terms: D000096:Acetone / Q000031:analogs & derivatives* / Q000737:chemistry; D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction
chemical_list: D056831:Coordination Complexes; D009943:Organophosphorus Compounds; C434331:phosphoramidite; D000096:Acetone; D007501:Iron; C008863:1-phenyl-2-propanone