Formic acid and formates
Deprotonated formic acid splits into hydride and CO2, wherefore it works as a reducing agent.
> Formic acid as an oxidizing agent.
Name Reactions
Reactions
Recent Literature
In a biphasic reaction media for the asymmetric biocatalytic reduction of
ketones with in situ cofactor regeneration, both enzymes (ADH
and FDH) remain stable. Reductions with poorly
water-soluble ketones were carried out at substrate concentrations of > 10 mM,
and alcohols were formed with good conversions in high enantioselectivity.
H. Groeger, W. Hummel, S. Buchholz, K. Drauz, T. V. Nguyen, C. Rollmann, H. Huesken, K. Abokitse, Org. Lett., 2003, 5, 173-176.
By careful selection of appropriate enzymes (alcohol dehydrogenases [ADH] and
cofactor recycling enzymes), cofactor recycling of NADH can be performed
in the presence of NADP+ recycling to achieve overall (R)- or
(S)-selective deracemisations
of sec-alcohols or stereoinversion representing a possible concept for a
“green” equivalent to the chemical-intensive Mitsunobu inversion.
C. V. Voss, C. C. Gruber, K. Faber, T. Knaus, P. Macheroux, W. Kroutil, J. Am. Chem. Soc., 2008,
130, 13969-13972.
An on-water Ir(III)-diamine catalysis represents an efficient, simple and
environmentally friendly catalytic system for the transfer hydrogenation of
aldehydes. The catalyst tolerates various synthetically useful groups
including nitro groups, halogens, ketones, esters and olefins.
X. Wu, J. Liu, X. Li, A. Zanotti-Gerosa, F. Hancock, D. Vinci, J. Ruan, J. Xiao, Angew. Chem. Int. Ed., 2006, 45, 6717-6722.
Asymmetric transfer
hydrogenation of various simple aromatic ketones by the Ru-TsDPEN
catalyst was shown to be feasible in aqueous HCOONa without calling for
any catalyst modification, furnishing ee's of up to 95% and
significantly faster rates than in the HCOOH-NEt3 azeotrope.
X. Wu, X. Li, W. Hems, F. King, J. Xiao, Org. Biomol. Chem., 2004, 2, 1818-1821.
An iridium-catalyzed, chemoselective, asymmetric transfer hydrogenation of α-substituted
acetophenones using formic acid as reductant can be performed in water and open
to air.
O. Soltani, M. A. Ariger, H. Vázquez-Villa, E. M. Carreira, Org. Lett., 2010,
12, 2893-2895.
A new diamine ligand for Ru-catalyzed asymmetric transfer hydrogenation (ATH)
enabled a highly enantioselective reduction of 2-acylarylcarboxylates.
Subsequent in situ lactonization under aqueous conditions provided efficient
access to a various 3-substituted phthalides in enantiomerically pure form.
B. Zhang, M.-H. Xu, G.-Q. Lin, Org. Lett., 2009,
11, 4712-4715.
A transformation of aldehydes into terminal olefins through reduction of the
corresponding enol triflates is effective with both linear and α-branched
aldehydes.
S. K. Pandey, A. E. Greene, J.-F. Poisson, J. Org. Chem.,
2007,
72, 7769-7770.
Pd/P(t-Bu)3 is an efficient and mild catalyst for selective
reduction of various alkenes under transfer-hydrogenation conditions leading to
the corresponding saturated derivatives in good yields.
J. M. Brunel, Synlett, 2007, 330-332.
A mild catalytic asymmetric transfer hydrogenation of β,β-disubstituted
nitroalkenes using formic acid as reductant in combination with an Ir catalyst
is conducted in water at low pH and open to air to give products in good yield
and selectivity.
O. Soltani, M. A. Ariger, E. M. Carreira, Org. Lett., 2009,
11, 4196-4198.
Various carbon-carbon double bonds in olefins and α,β-unsaturated ketones
were effectively reduced to the corresponding alkanes and saturated ketones,
using ammonium formate as a hydrogen transfer agent in the presence of Pd/C
as catalyst in refluxing methanol.
Z. Paryzek, H. Koenig, B. Tabacka, Synthesis, 2003, 2023-2026.
A microwave-assisted, palladium-catalyzed catalytic transfer hydrogenation of different homo- or heteronuclear
organic compounds using formate salts as a hydrogen source was performed in ([bmim][PF6]. Essentially pure products could be isolated in
moderate to excellent yields by simple liquid-liquid extraction.
H. Berthold, T. Schotten, H. Hönig, Synthesis, 2002, 1607-1610.
Knoevenagel condensation followed by hydrogenation with triethylamine-formic
acid in the presence of a ruthenium-amido complex allowed an α-alkylation of
various nitriles with carbonyl compounds in good yields. The reaction tolerated
various functional groups, including nitro and chloro groups, and a furan ring.
H. Sun, D. Ye, H. Jiang, K. Chen, H. Liu, Synthesis, 2010,
2577-2582.
Transfer hydrogenation utilizing palladium on carbon and formic acid provides a
fast and simple removal of O-benzyl groups from carbohydrate derivatives.
However, when formic acid is the hydrogen donor, a large amount of palladium has
to be used.
T. Bieg, W. Szeja, Synthesis,
1985,
76-77.
Nanopalladium particles supported on a amphiphilic polystyrene-poly(ethylene
glycol) resin catalyzed hydrogenation of olefins and hydrodechlorination of
chloroarenes under aqueous conditions.
R. Nakao, H. Rhee, Y. Uozumi, Org. Lett., 2005,
7, 163-165.
An operationally simple, tin-free reductive dehalogenation system allows the
reduction of activated C-X bonds in good yields with excellent functional-group
tolerance and chemoselectivity over aryl and vinyl C-X bonds in the presence of
the well-known visible-light-activated photoredox catalyst Ru(bpy)3Cl2
in combination with iPr2NEt and HCO2H or Hantzsch
ester as the hydrogen atom donor.
J. M. R. Narayanam, J. W. Tucker, C. R. J. Stephenson, J. Am. Chem. Soc., 2009,
131, 8756-8757.
Various di- and triarylfurans were prepared in high yields from
but-2-ene-1,4-diones and but-2-yne-1,4-diones using formic acid in the
presence of a catalytic amount of palladium on carbon in poly(ethylene
glycol)-200 as solvent under microwave irradiation.
H. S. P. Rao, S. Jothilingam, J. Org. Chem., 2003, 68, 5392-5394.
Several aryl-substituted pyrrole derivates were prepared conveniently in a
microwave-assisted one pot-reaction from but-2-ene-1,4-diones and
but-2-yne-1,4-diones via Pd/C-catalyzed hydrogenation of the carbon-carbon
double bond/triple bond followed by amination-cyclization.
H. S. P. Rao, S. Jothilingam, H. W. Scheeren, Tetrahedron, 2004, 60, 1625-1630.
The synthesis of 3,5-dimethyl-N-nitro-1-pyrazole-1-carboxamidine (DMNPC) has been optimised. A detailed protocol for the preparation of a range of guanidines via nitroguanidines
is described using DMNPC as guanidinylating reagent.
J. A. Castillo-Meléndez, B. T. Golding, Synthesis,
2004, 1655-1663.
Amidines can be prepared by
reducing acylated amidoximes with potassium formate. This method has proved to
be very simple and effective.
K. Nadrah, M. Sollner Dolenc, Synlett, 2007,
1257-1258.
