Categories: C=O Bond Formation > Synthesis of carboxylic acids >
Synthesis of carboxylic acids by hydration and oxidation of alkynes
Recent Literature
An efficient method for the oxidative cleavage of internal and terminal
alkynes to carboxylic acids using a combination of RuO2/Oxone/NaHCO3
in a CH3CN/H2O/EtOAc solvent system is described.
Various alkynes, regardless of their electron density, were oxidized to
carboxylic acids in excellent yield.
D. Yang, F. Chen, Z.-M. Dong, D.-W. Zhang, J. Org. Chem., 2004,
69, 209-212.
The presence of catalytic amounts of carbon tetrabromide enables an aerobic
photooxidative cleavage of carbon-carbon triple bonds to carboxylic acids under
photoirradiation.
T. Yamaguchi, T. Nobuta, Y. Kudo, S.-i. Hirashima, N. Tada, T. Miura, A. Itoh, Synlett, 2013, 24,
607-610.
A metal-free esterification of a broad range of alkynes with alcohols in the
presence of phenyliodine bis(trifluoroacetate) produces esters in good yields
via carbon triple bond cleavage. The transformation proceeds via
hydroxyethanones and ethanediones as intermediates and exhibits a broad
substrate scope and good functional group tolerance.
Q. Jiang, A. Zhao, B. Xu, J. Jia, X. Liu, C. Guo, J. Org. Chem., 2014,
79, 2709-2715.
Half-sandwich ruthenium complexes activate terminal alkynes toward
anti-Markovnikov hydration and reductive hydration under mild conditions.
Propargylic alcohols can be converted to 1,3-diols in high yield and with
retention of stereochemistry at the propargylic position. The method is also
amenable to formal anti-Markovnikov reductive amination and oxidative hydration
reactions to access linear amines and carboxylic acids, respectively.
M. Zeng, S. B. Herzon, J. Org. Chem.,
2015,
80, 8604-8618.
The reaction of alkyl-substituted sec-ethoxyalkynyl acetates with water
catalyzed by Hg(OTf)2 afforded α,β-unsaturated esters in excellent
yield with high catalytic turnover under very mild reaction conditions with
virtually complete E-selectivity.
M. Nishizawa, H. Hirakawa, Y. Nakagawa, H. Yamamoto, K. Namba, H. Imagawa, Org. Lett., 2007,
9, 5577-5580.
A Au(I)-catalyzed hydroalkoxylation/Claisen rearrangement cascade reaction of
aryl ynol ethers and ynamides with allylic alcohols provides γ,δ-unsaturated
esters or amides, respectively. The [Au(IPr)NTf2] catalyst is most
effective for this reaction, and the reaction proceeds under mild conditions in
an atom-economical way.
S. Misawa, A. Miyairi, Y. Oonoshi, S. P. Nolan, Y. Sato, Synthesis, 2021, 53,
4644-4645.
An iodo Meyer-Schuster rearrangement of 3-alkoxypropargyl
alcohols using iodine or NIS in
dichloromethane at ambient temperature produces α-iodo-α,β-unsaturated esters
in good yields. Secondary alcohols gave Z-isomers exclusively.
S. Puri, N. Thirupathi, M. S. Reddy, Org. Lett.,
2014,
16, 5246-5249.
