New Chiral Phosphoramidite Complexes of Iron as Catalytic Precursors in the Oxidation of Activated Methylene GroupsMolecules (2010)
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).
Publication DateApril 12, 2010
Citation InformationPushkar Shejwalkar, Nigam P. Rath and Eike B. Bauer. "New Chiral Phosphoramidite Complexes of Iron as Catalytic Precursors in the Oxidation of Activated Methylene Groups" Molecules Vol. 15 Iss. 4 (2010) p. 2631 - 2650
Available at: http://0-works.bepress.com.library.simmons.edu/nigam-rath/118/