Categories: Synthesis of O-Heterocycles, C-O Bond Formation, Synthesis of Cyclic Ethers >
Synthesis of cyclic ethers
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| Epoxides |
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Oxetanes |  |
| Tetrahydro- furans |
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Tetrahydro- pyrans |
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Morpholines |  |
Recent Literature
The platinum-catalyzed hydroalkoxylation of γ- and δ-hydroxy olefins
tolerated various substitution patterns and a number of functional groups
including pivaloate and acetate esters, amides, silyl and benzyl ethers, and
pendant hydroxyl and olefinic groups.
H. Qian, X. Han, R. A. Widenhoefer, J. Am. Chem. Soc.,
2004, 126, 9536-9537.
The reaction of tertiary 1,4- and 1,5-diols with cerium ammonium nitrate at room
temperature gives tetrahydrofuran and tetrahydropyran derivatives in high yield
and stereoselectivity. Various fragrant compounds have been synthesized using
this method.
E. J. Alvarez-Manzaneda, R. Chabouna, E. Alvarez, E. Cabrera, R.
Alvarez-Manzaneda, A. Haidour, J. M. Ramos, Synlett, 2006,
1756-1758.
Medium-sized cyclic ethers have been effectively synthesized through
intramolecular reductive coupling of dialdehydes in the presence of a
hydrosilane and low loadings of AgNTf2 as catalyst at 25°C. The
catalytic system is also suitable for the coupling of two different
monoaldehydes to provide unsymmetrical ethers. This protocol features broad
functional group compatibility and high product diversity.
T. Liang, G. Dong, C. Li, X. Xu, Z. Xu, Org. Lett.,
2022, 24, 1817-1821.
The Au(I)-catalyzed intramolecular hydroamination of N-allenyl
carbamates was effective for the formation of various cyclic amines. γ-Hydroxy
and δ-hydroxy allenes underwent Au-catalyzed intramolecular
hydroalkoxylation to form the corresponding
oxygen heterocycles in good yield. 2-Allenyl indoles
underwent Au-catalyzed intramolecular hydroarylation to form 4-vinyl tetrahydrocarbazoles in good yield.
Z. Zhang, C. Liu, R. E. Kinder, X. Han, H. Qian, R. A. Widenhoefer, J. Am. Chem. Soc.,
2006, 128, 9066-9073.
Treatment of 3-[(alkoxycarbonyl)alkyl]-substituted conjugated cycloalkenones
with diisobutylaluminum hydride at -78 °C followed by acid quenching
furnishes spiro ethers, whereas the corresponding 3-(carboxyalkyl)-substituted
cycloalkenones generate spiro lactones upon reaction with sodium borohydride
at 30 °C followed by acid quenching.
M.-C. P. Yeh, Y.-C. Lee, T.-C. Young, Synthesis, 2006, 3621-3624.
A combination of Pd(II)/bis-sulfoxide C-H activation and Lewis acid co-catalysis
enables the synthesis of chroman, isochroman, and pyran motifs from a wide range
of alcohols. Mechanistic studies suggest that the reaction proceeds via initial
C-H activation followed by a novel inner-sphere functionalization pathway.
S. E. Ammann, G. T. Rice, M. C. White, J. Am. Chem. Soc., 2014,
136, 10834-10837.
A nucleophilic substitution of alkyl fluorides was achieved in intramolecular
reactions with O- and N-nucleophiles. The reaction is influenced by the nature
of nucleophiles, the size of the ring to be formed, and the comformational
rigidity of the precursors.
L. Zhang, W. Zhang, J. Liu, J. Hu, J. Org. Chem., 2009,
74, 2850-2853.
A highly reactive and confined imidodiphosphorimidate (IDPi) catalyst enables a
direct enantioselective synthesis of substituted oxygen heterocycles from lactol
acetates and enolsilanes. Various chiral oxygen heterocycles, including
tetrahydrofurans, tetrahydropyrans, oxepanes, chromans, and dihydrobenzofurans,
were obtained in excellent enantioselectivities.
S. Lee, P. S. J. Kaib, B. List, J. Am. Chem. Soc., 2017,
139, 2156-2159.
A bifunctional aminoboronic acid facilitates intramolecular aza- and oxa-Michael
reactions of α,β-unsaturated carboxylic acids. The combination of an arylboronic
acid with a chiral aminothiourea enables enantioselective conversions to afford
the desired heterocycles in high yields and ee’s (up to 96% ee).
T. Azuma, A. Murata, Y. Kobayashi, T. Inokuma, Y. Takemoto, Org. Lett.,
2014,
16, 4256-4259.
Dehydration of 1,6-diols by treatment with BF3·OEt2 in
dichloromethane gave tetrahydrobenzoxepines in very good yields, whereas
1,7-diols did not undergo dehydration.
M. Yus, T. Soler, F. Foubelo, Tetrahedron, 2002, 58,
7009-7016.
An efficient and regioselective Yb(OTf)3-promoted
palladium-catalyzed oxidative cyclization of γ-heteroalkenyl β-keto amides
has been developed. Under simple aerobic condition, various six-, seven-,
and eight-membered-ring N- and O-heterocycles were obtained in excellent yield.
K.-T. Yip, J.-H. Li, O.-Y. Lee, D. Yang, Org. Lett.,
2005, 7, 5717-5719.
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Diastereoselective and Enantioselective Construction of Cyclic Ethers Stereocontrolled Construction of Cyclic Ethers Enantioselective Construction of Naturally-Occurring Cyclic Ethers |