Categories: O-H Bond Formation >
Reduction of carboxyl compounds to alcohols
| Related
|
Name Reactions
Recent Literature
Pincer ruthenium complexes bearing a monodentate N-heterocyclic carbene
ligand have been used as powerful hydrogenation catalysts. With an atmospheric
pressure of hydrogen gas, aromatic, heteroaromatic, and aliphatic esters as well
as lactones were converted into the corresponding alcohols.
O. Ogata, Y. Nakayama, H. Nara, M. Fujiwhara, Y. Kayaki, J. Zhu, Org. Lett.,
2016, 18, 3894-3897.
A catalytic system of cobalt(II) chloride and diisopropylamine in combination
with NaBH4 showed excellent activity in the chemoselective reduction
of various carboxylic esters to their corresponding alcohols in very good
yields under mild conditions. Unsaturated carboxylic esters give saturated
alcohols in high yields.
A. R. Jagdale, A. S. Paraskar, A. Sudalai, Synthesis, 2009,
660-664.
Ammonia-borane reduces acids to alcohols at room temperature in the
presence of catalytic TiCl4. This process tolerates a variety of
potentially reactive functional groups, including N-protected amino acids, nitriles and, to some extent, esters. Aliphatic acids can be selectively reduced
in the presence of aromatic acids.
P. V. Ramachandran, A. A. Alawaed, H. J. Hamann, Org. Lett., 2022, 24,
8481-8486.
TiCl4 mediates a facile and selective room temperature
deoxygenation of both aromatic and aliphatic carboxylic esters to ethers in the
presernce of BH3-NH3. This process is compatible with
various potentially sensitive functional groups. Substituting TiCl4 by BF3-Et2O
alters the reaction pathway, reducing esters to alcohols.
P. V. Ramachandran, A. A. Alawaed, H. J. Hamann, Org. Lett., 2023, 25,
6902-6906.
A well-defined manganese(I) complex with a commercially available
bisphosphine ligand catalyzes selective and efficient hydrosilylations of a
broad range of esters to alcohols at 100 °C under solvent-free conditions.
R. R. Behera, R. Ghosh, S. Panda, S. Khamari, B. Bagh,
Org. Lett., 2020, 22, 3642-3648.
A manganese-catalyzed chemoselective
hydroboration of carboxylic acids to the corresponding alcohols offers a high turnover number and turnover frequency at 25°C. This method
tolerates electronically and sterically differentiated substrates with high
chemoselectivity. Importantly, aliphatic long-chain fatty acids, including
biomass-derived compounds, can efficiently be reduced.
M. K. Barman, K. Das, B. Maji, J. Org. Chem., 2019, 84,
1570-1579.
The ruthenium complex [(η6-p-cymene){(IMes)P}RuCl] was used
for efficient hydroborations of a wide range of nitriles, carboxylic
esters, and carboxamides in neat pinacolborane (HBpin) under comparatively mild
reaction conditions (60-80 °C, 3-5 mol % catalyst loading).
J. Bhattacharjee, D. Blockfeld, M. Tamm, J. Org. Chem., 2022, 87,
1098-1109.
Odorless Dod-S-Me and MMS are developed as efficient borane carriers. The
yields of hydroborations and reductions with the borane complex of Dod-S-Me
are very high. The recovery of Dod-S-Me after the reaction is quantitative.
P. K. Patra, K. Nishide, K. Fuji, M. Node, Synthesis, 2004,
1003-1006.
Aliphatic carboxyl derivatives (acids, acyl chlorides, esters) and aldehydes
were efficiently reduced to the methyl group by HSiEt3 in the
presence of catalytic amounts of B(C6F5)3.
Aromatic carboxylic acids, as well as other carbonyl functional equivalents,
underwent smooth partial reduction to the corresponding TES-protected benzylic
alcohols.
V. Gevorgyan, M. Rubin, J.-X. Liu, Y. Yamamoto, J. Org. Chem, 2001,
66, 1672-1675.
Solid amidophosphine boranes were synthesized to replace more commonly used
borane reagents. These compounds demonstrated excellent reactivity and functional
group tolerance toward a wide variety of nitriles, alkynes, and carboxylic
acids, affording the corresponding ammonium salts, alkenes, and alcohols in good
yield.
R. Kumar, R. K. Meher, J. Sharma, A. Sau, T. K. Panda, Org. Lett., 2023, 25,
7923-7927.
The use of D2O and SmI2 as a mild single-electron
donor enables a general single-electron transfer reductive deuteration of
readily commercially available aromatic esters for the synthesis of
α,α-dideuterio benzyl alcohols. This operationally convenient method features
high deuterium incorporations and very good functional group tolerance.
S. Luo, C. Weng, Y. Ding, C. Ling, M. Szostak, X. Ma, J. An, Synlett, 2021,
32,
51-56.
The use of pentafluorophenyl esters as ketyl radical precursors, SmI2
as a mild reducing agent, and D2O as the deuterium source enables a
highly chemoselective synthesis of α,α-dideuterio alcohols with exquisite
incorporation of deuterium. This system tolerates a variety of functional groups.
H. Li, Y. Hou, C. Liu, Z. Lai, L. Ning, R. Szostak, M. Szostak, J. An,
Org. Lett., 2020, 22, 1249-1253.
Cost-effective sodium dispersion mediates an atom economical single electron
transfer (SET) reductive deuteration of acyl chlorides in the presence of EtOD-d1
as deuterium donor. The reaction offers excellent regioselectivity and >92%
deuterium incorporations.
H. Li, M. Peng, L. Wang, T. Jiang, X. Li, Y. Fu, Z. Hu, J. An, Org. Lett., 2024,
26,
719-723.
A practical and scalable single electron transfer reduction enables the
reduction and reductive deuteration of tertiary amides in the presence of sodium
dispersions. The chemoselectivity of this method highly depends on the nature of
the proton donor. Whereas the combination of Na/EtOH affords alcohol products,
the use of Na/NaOH/H2O leads to the formation of amines.
B. Zhang, H. Li, Y. Ding, Y. Yan, J. An, J. Org. Chem., 2018, 83,
6006-6014.
A highly chemoselective direct reduction of primary, secondary, and tertiary
amides to alcohols in high yields in presence of SmI2/amine/H2O
proceeds via C-N bond cleavage in a carbinolamine intermediate and shows
excellent functional group tolerance. The expected C-O cleavage products are not
formed under the reaction conditions. Notably, the method provides direct access
to acyl-type radicals from unactivated amides under mild conditions.
M. Szostak, M. Spain, A. J. Eberhard, D. J. Procter, J. Am. Chem. Soc., 2014,
136, 2268-2271.
A simple and practical protocol for the reduction of carboxylic acids via in
situ formation of hydroxybenzotriazole esters followed by reaction with sodium
borohydride gives the corresponding alcohols. The reaction proceeds with
excellent yields in the presence of water.
J. A. Morales-Serna, E. García-Rios, J. Bernal, E. Paleo, R. Gaviño, J. Cárdenas, Synthesis, 2011,
1375-1382.
The preparation of alkenyl halides of any length from inexpensive starting
reagents is reported. Standard organic transformations were used to prepare
straight-chain α-olefin halides in excellent overall yields with no
detectable olefin isomerization and full recovery of any unreacted starting
material.
T. W. Baughman, J. C. Sworen, K. B. Wagener, Tetrahedron, 2004, 60, 10943-10948.
The use of diethylaluminum benzenethiolate enables an efficient discrimination
between aldehydes and other carbonyl functions and allows a chemoselective in
situ reduction of ketones and methyl esters in the presence of aldehydes without
using traditional protecting group methodologies.
G. Bastug, S. Dierick, F. Lebreux, I. E. Markó, Org. Lett., 2012,
14, 1306-1309.
| Related |
