Iron (low valent)
Recent Literature
Fe(0) is cost-effective, environmentally friendly alternative to Cr(II) for
the olefination of carbonyls by activated polyhalides. Fe(0) proved
compatible with a wide range of functionality, such as unprotected phenol,
aryl nitro, carboxylic acid, and alkyl nitrile.
J. R. Falck, R. Bejot, D. K. Barma, A. Bandyopadhyay, S. Joseph, C. Mioskowski, J. Org. Chem., 2006, 71, 8178-8182.
An operationally simple and very efficient Reformatsky reaction of aldehydes has
been carried out in THF in the presence of low valent iron or copper which were
prepared in situ employing a bimetal redox strategy through reduction of Fe(III)
or Cu(II) salts with magnesium.
A. Chattopadhyay, A. Kr. Dubey, J. Org. Chem., 2007,
72, 9357-9359.
An iron complex containing electronically coupled acidic and hydridic hydrogens
catalyzes the hydrogenation of ketones under mild conditions and shows high
chemoselectivity for aldehydes, ketones, and imines. Isolated carbon double and
triple bonds, aryl halides, nitrates, epoxides, and ester functions are
unaffected by the hydrogenation conditions.
C. P. Casey, H. Guan, J. Am. Chem. Soc., 2007,
129, 5816-5817.
A facile and practical method for the synthesis of N-acetyl
α-arylenamides from the corresponding ketoximes with ferrous acetate as the
reducing reagent offers mild reaction conditions, simple purification procedures,
and high yields for a variety of N-acetyl enamides.
W. Tang, A. Capacci, M. Sarvestani, X. Wei, N. K. Yee, C. H. Senanayake, J. Org. Chem., 2009,
74, 9528-9530.
An intermolecular reductive Schiff base formation from nitroarenes and
benzaldehydes to yield diarylimines is carried out in the presence of iron
powder and dilute acid. This process tolerates various functional groups and
often proceeds quantitatively with no need for purification.
A. L. Korich, T. S. Hughes, Synlett, 2007,
2602-2604.
An efficient Fe/CaCl2 system enables the reduction of nitroarenes and
reductive cleavage of azo compounds by catalytic transfer hydrogenation in the
presence of sensitive functional groups including halides, carbonyl, aldehyde,
acetyl, nitrile, and ester substituents with excellent yields. The simple
experimental procedure and easy purification make the protocol advantageous.
S. Chandrappa, T. Vinaya, T. Ramakrishnappa, K. S. Rangappa, Synlett, 2010,
3019-3022.
S. Chandrappa, T. Vinaya, T. Ramakrishnappa, K. S. Rangappa, Synlett, 2010,
3019-3022.
Reduction of o-nitroarylcarbaldehydes o-aminoarylcarbaldehydes with iron
in the presence of a catalytic amount of aqueous hydrochloric acid followed by
in situ condensation of the resulting amines with ketones or aldehydes (Friedlaender
quinoline synthesis) gives mono- or disubstituted quinolines, respectively, in
very good yields.
A.-H. Li, D. J. Beard, H. Coate, A. Honda, M. Kadablbajoo, A. Kleinberg, R.
Laufer, K. M. Mulvihill, A. Nigro, P. Rastogi, M. W. Siu, A. G. Steinig, T.
Wang, D. Werner, A. P. Crew, M. J. Mulvihill, Synthesis, 2010,
1629-1632.
A tandem condensation of a cyanoimidate with an amine followed by reductive
cyclization in an iron-HCl system enables an efficient route to N4-substituted
2,4-diaminoquinazolines. An additional N-alkylation can produce two fused
heterocycles in a one-pot procedure.
P. Yin, N. Liu, Y.-X. Deng, Y. Chen, Y. Deng, L. He, J. Org. Chem., 2012,
77, 2649-2658.
