Isopropanol, 2-Propanol
see also: 2-butanol
Name Reactions
Meerwein-Ponndorf-Verley Reduction (MPV)
Recent Literature
[Cp*Ir(2,2′-bpyO)(H2O)] is a highly efficient and general catalyst
for transfer hydrogenation of carbonyl compounds and chemoselective transfer
hydrogenation of unsaturated aldehydes with isopropanol under neutral conditions.
The reaction tolerates deducible groups such as nitro, cyano, ester, and halide.
R. Wang, Y. Tang, M. Xu, C. Meng, F. Li, J. Org. Chem., 2018, 83,
2274-2281.
Catalytic MPV reduction was successfully carried out using iPrOH as the
reducing agent and simple alkylaluminum reagents as precatalysts, that were
converted to highly active low-aggregation aluminum alkoxides. When chiral
hydride sources were utilized in the reduction of 2-chloroacetophenone, high
enantioselectivity was observed.
E. J. Campbell, H. Zhou, S. T. Nguyen,
Org. Lett., 2001, 3, 2391-2393.
A very simple and inexpensive catalytic system based on abundant
manganese as transition metal and on an inexpensive phosphine-free bidendate
ligand enables the reduction of a broad range of carbonyl derivatives with
2-propanol as hydrogen donor at room temperature. The reaction runs with low
catalyst loading and exhibits a good functional group tolerance.
A. Bruneau-Voisine, D. Wang, V. Dorcet, T. Roisnel, C. Darcel, J.-B. Sortais, Org. Lett.,
2017, 19, 3656-3659.
Indium tri(isopropoxide)-catalyzed Meerwein-Ponndorf-Verley reduction of
aliphatic and aromatic aldehydes in 2-propanol gave selectively the
corresponding primary alcohols in good to excellent yields at room temperature.
The reaction tolerates a wide range of functional groups including alkene, ether,
ketone, ester, nitrile, and nitro.
J. Lee, T. Ryu, S. Park, P. H. Lee, J. Org. Chem., 2012,
77, 4821-4825.
A convenient disproportionation or reduction of aldehydes is promoted by
lithium bromide and triethylamine in a solvent-free environment at room
temperature. Products of Cannizzaro or Tishchenko reactions can be isolated
using different workup methods. In the presence of a hydrogen donor alcohol, a Meerwein-Ponndorf-Verley reaction
takes place.
M. M. Mojtahedi, E. Akbarzadeh, R. Sharifi, M. S. Abaee, Org. Lett., 2007,
9, 2791-2793.
The reduction of ketones and aldehydes with lanthanide metals (La, Ce,
Sm, Yb) and a catalytic amount of iodine (5 mol %) in iPrOH
proceeded smoothly to produce the corresponding alcohols as the major
products in good yield, while in THF, methanol, and ethanol the pinacols
were mainly produced. The yields of alcohols were improved most
effectively by the use of Sm metal.
S.-I. Fukuzawa, N. Nakano, T. Saitoh, Eur. J. Org. Chem., 2004, 2863-2867.
A Mild and Efficient Flow Procedure for the Transfer Hydrogenation of
Ketones and Aldehydes using Hydrous Zirconia
C. Battilocchio, J. M. Hawkins, S. V. Ley, Org. Lett., 2013,
15, 2278-2281.
Pincer-aryl ruthenium(II) complexes form active catalysts in the reduction
of ketones by hydrogen transfer in iPrOH using KOH as promoter. At a
KOH/Ru molar ratio of 20/1 only trace amounts of aldol products are formed.
Under these conditions, the σ Ru-C bond is stable and the [Ru(PCP)PPh3]
fragment is preserved.
P. Dani, T. Karlen, R. A. Gossage, S. Gladiali, G. van Koten, Angew. Chem., 2000, 112, 759-761.
An asymmetric α-alkylative reduction of prochiral ketones with primary
alcohols has been disclosed. The reaction is catalyzed by both iridium and
ruthenium complexes and gave optically active alcohols with elongation of
the carbon skeleton with high enantioselectivity.
G. Onodera, Y. Nishibayashi, S. Uemura, Angew. Chem. Int. Ed., 2006,
45, 3819-3822.
In the presence of a phenol ligand, a cationic ruthenium hydride complex
exhibited high catalytic activity for the hydrogenolysis of carbonyl compounds
to yield the corresponding aliphatic products. The reaction showed exceptionally
high chemoselectivity toward the carbonyl reduction over alkene hydrogenation.
N. Kalutharage, C. S. Yi, J. Am. Chem. Soc., 2015,
137, 11105-11114.
Nickel nanoparticles catalyse the reductive amination of aldehydes by transfer
hydrogenation with isopropanol at 76°C.
F. Alonso, P. Riente, M. Yus, Synlett, 2008, 1289-1292.
A nickel-catalyzed enantioselective transfer hydrogenation of N-sulfonyl
imines offers excellent α-selectivity. The use of inexpensive 2-propanol-d8
as a deuterium source enables a deuteration with high deuterium content. In
addition, no deuteration of β-C-H and the remote C-H of N-sulfonyl amines
occurred, which is hard to achieve using other imines or by hydrogen isotope
exchange with D2O.
P. Yang, L. Zhang, K. Fu, Y. Sun, X. Wang, J. Yue, Y. Ma, B. Tang,
Org. Lett., 2020, 22, 8278-8284.
A selective transfer hydrogenation of α,β-unsaturated carbonyl compounds to
saturated ones in very good yields was achieved by the use of 2-propanol as a
hydrogen donor under the influence of catalytic amounts of [Ir(cod)Cl]2,
1,3-bis(diphenylphosphino)propane (dppp), and Cs2CO3. The
reduction of carbonyl compounds to alcohols can also promoted by the same
catalytic system.
S. Sakaguchi, T. Yamaga, Y. Ishii, J. Org. Chem., 2001,
66, 4710-4712.
Enantioselective transfer hydrogenation of 1,1-dimethylallene in the presence of
aldehydes and 2-propanol or primary alcohols without 2-propanol employing a
cyclometalated iridium C,O-benzoate derived from allyl acetate, m-nitrobenzoic
acid, and (S)-SEGPHOS delivers reverse-prenylation products in very good
yields and enantioselectivities.
S. B. Han, I. S. Kim, H. Han, M. J. Krische, J. Am. Chem. Soc., 2009,
131, 6916-6917.
Two complementary dual catalytic systems enable a highly regioselective
reductive hydration of terminal alkynes to yield branched or linear alcohols in
very good yield. The method is compatible with terminal, di-, and trisubstituted
alkenes. This reductive hydration constitutes a strategic surrogate to alkene
oxyfunctionalization and may be of utility in multistep settings.
L. Li, S. B. Herzon, J. Am. Chem. Soc., 2012,
134, 17376-17378.
L. Li, S. B. Herzon, J. Am. Chem. Soc., 2012,
134, 17376-17378.
In a highly regio- and stereoselective hydroarylation, hydroalkenylation, and
hydrobenzylation of ynol ethers, a Pd-catalyzed reductive addition of
organohalides, including aryl, alkenyl, and benzyl halides, in the presence of
2-propanol gives α,β- and β,β-disubstituted olefinic ethers in good yields.
W. Cui, J. Yin, R. Zheng, C. Cheng, Y. Bai, G. Zhu, J. Org. Chem., 2014,
79, 3487-3493.
Rh(III) catalyzes an intermolecular anti-Markovnikov hydroamidation of
unactivated alkenes with dioxazolone amidating reagents and isopropanol as
hydride source under mild conditions. The reaction tolerates a wide range of
functional groups and efficiently converts also electron-deficient, styrenes,
and 1,1-disubstituted alkenes to their corresponding linear amides.
N. Wagner-Carlberg, T. Rovis, J. Am. Chem. Soc.,
2022, 144, 22426-22432.
A dimeric Ni(I) catalyst and an exogenous alkoxide base promote
Markovnikov-selective hydroarylation (alkenylation) of unactivated and activated
olefins using organo bromides or triflates derived from widely available phenols
and ketones. Products bearing aryl- and alkenyl-substituted tertiary and
quaternary centers could be isolated in very good yield and excellent
regioisomeric ratios.
C.-F. Liu, X. Luo, H. Wang, M. J. Koh, J. Am. Chem. Soc.,
2021, 143, 9498-9506.
Aryl halides are reduced into the corresponding arenes in high yields, using
2-propanol as reductant and solvent, cesium carbonate as base, and di-tert-butyl
peroxide (or di-tert-butyl hyponitrite) as radical initiator. This simple
system reduces various aryl bromides and iodides through a SET mechanism with
high functional-group tolerance.
R. Ueno, T. Shimizu, E. Shirakawa,
Synlett, 2016, 27, 747-744.
A simple and efficient Ru(II)-catalyzed transfer hydro-dehalogenation using
2-propanol as the hydride source is applicable for various aromatic halides and
α-haloesters and amides. The potential synthetic application of this method was
demonstrated by efficient gram-scale transformation with catalyst loading as low
as 0.5 mol %.
T. You, Z. Wang, J. Chen, Y. Xia, J. Org. Chem.,
2017, 82, 1340-1346.
A nickel-catalyzed hydrodeoxygenation of aryl sulfamates enables the use of
alcohols as mild reductants. A variety of functional groups and heterocycles
were tolerated in this reaction system to give the desired products in high
yields.
K. Matsuo, M. Kuriyama, K. Yamamoto, Y. Demizu, K. Nishida, O. Onomura, Synthesis, 2021, 53,
4449-4460.
Transfer hydrogenation of chiral α,β-unsaturated N-(tert-butylsulfinyl)ketimines
followed by removal of the sulfinyl group provides primary allylic amines with
enantiomeric excesses from 97 to >99%.
E. Selva, Y. Sempere, D. Ruiz-Martínez, O. Pablo, D. Guijarro, J. Org. Chem.,
2017, 82, 13693-13699.
A continuous flow method for the selective reduction of aromatic nitriles to the
corresponding primary amines is based on a ruthenium-catalysed
transfer-hydrogenation process with isopropanol as both solvent and reducing
agent.
R. Labes, D. González-Calderón, C. Battilocchio, C. Mateos, G. R. Cumming, O.
de Frutos, J. A. Rincón, S. V. Ley,
Synlett, 2017, 28, 2855-2858.
Reductive dimerization of nitrosobenzenes enables an effective and simple
preparation of substituted azoxybenzenes without additional catalysts/reagents.
This procedure can be applied to substrates with a wide range of
substitution patterns.
Y.-F. Chen, J. Chen, L.-J. Lin, G. J. Chuang, J. Org. Chem.,
2017, 82, 11620-11630.
The use of i-PrOH as environmentally benign hydrogen surrogate enables
a ligand-free Co-catalyzed chemoselective reductive cyclization cascade of
enone-tethered aldehydes. The selectivity between Michael-Aldol cycloreduction
cascade and oxa-Michael cascade can be adjusted by the addition of TEMPO as a
steric Lewis bases to provide 1H-indenes and dihydroisobenzofurans,
respectively.
S.-S. Ma, B.-L. Jiang, Z.-K. Yu, S.-J. Zhang, B.-H. Xu, Org. Lett., 2021, 23,
3873-3878.
The use of i-PrOH as environmentally benign hydrogen surrogate enables
a ligand-free Co-catalyzed chemoselective reductive cyclization cascade of
enone-tethered aldehydes. The selectivity between Michael-Aldol cycloreduction
cascade and oxa-Michael cascade can be adjusted by the addition of TEMPO as a
steric Lewis bases to provide 1H-indenes and dihydroisobenzofurans,
respectively.