Organic Letters
Letter
(d) Umezu, S.; dos Passos Gomes, G.; Yoshinaga, T.; Sakae, M.;
Matsumoto, K.; Iwata, T.; Alabugin, I.; Shindo, M. Regioselective
One-Pot Synthesis of Triptycenes via Triple-Cycloadditions of Arynes
to Ynolates. Angew. Chem., Int. Ed. 2017, 56, 1298−1302. Recent
application using ynolates: (e) Winterton, S. E.; Ready, J. M. [3 + 2]-
Cycloadditions of Azomethine Imines and Ynolates. Org. Lett. 2016,
18, 2608−2611. (f) Wu, J.-L.; Lu, Y.-S.; Tang, B.; Peng, X.-S. Total
Syntheses of Shizukaols A and E. Nat. Commun. 2018, 9, 4040.
(g) Nader, M. W.; Oberdorfer, F. [11C]Lithium Trimethylsilyl
Ynolate: A New [11C] Precursor and Its Application in Heterocyclic
Synthesis. Tetrahedron Lett. 2011, 52, 2309−2311.
lithium−halogen exchange strategy because readily accessible
starting materials bearing functional groups are used. It is
noteworthy that no lithium alkoxide coexists in the reaction
because the leaving group is the less basic lithium 2,6-di-tert-
butylphenoxide. This method will be especially useful for the
preparation of functionalized ynolates in organic synthesis.
ASSOCIATED CONTENT
* Supporting Information
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The Supporting Information is available free of charge on the
(6) (a) Shindo, M.; Sato, Y.; Koretsune, R.; Yoshikawa, T.;
Matsumoto, K.; Itoh, K.; Shishido, K. Synthesis of α,α-Dibromo
Esters as Precursors of Ynolates. Chem. Pharm. Bull. 2003, 51, 477−
478. (b) Shindo, M.; Matsumoto, K.; Shishido, K. Generation of
Ynolate and Z-Selective Olefination of Acylsilanes: (Z)-2-Methyl-3-
Trimethylsilyl-2-Butenoic Acid. Org. Synth. 2007, 84, 11−21.
Experimental details, and 1H NMR and 13C NMR
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(7) Haner, R.; Laube, T.; Seebach, D. Regio- and Diastereoselective
AUTHOR INFORMATION
Preparation of Aldols from α-Branched Ketone Enolates Generated
from BHT Ester Enolates and Organolithium ReagentsIn Situ
Generation and Trapping of Ketenes from Ester Enolates. J. Am.
Chem. Soc. 1985, 107, 5396−5403.
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Corresponding Author
ORCID
(8) Heathcock, C. H.; Pirrung, M. C.; Montgomery, S. H.; Lampe, J.
Acyclic Stereoselection-13. Aryl Esters: Reagents for Threo-
Aldolization. Tetrahedron 1981, 37, 4087−4095.
(9) Shindo, M.; Sato, Y.; Yoshikawa, T.; Koretsune, R.; Shishido, K.
Stereoselective Olefination of Unfunctionalized Ketones via Ynolates.
J. Org. Chem. 2004, 69, 3912−3916.
Notes
The authors declare no competing financial interest.
(10) (a) Bates, T. F.; Clarke, M. T.; Thomas, R. D. Unusual Stability
of an Alkyllithium Dimer. Preparation, Properties, and Decomposition
Mechanism of tert-Butyllithium Dietherate Dimer. J. Am. Chem. Soc.
1988, 110, 5109−5112. (b) Stanetty, P.; Mihovilovic, M. D. Half-
Lives of Organolithium Reagents in Common Ethereal Solvents. J.
Org. Chem. 1997, 62, 1514−1515.
ACKNOWLEDGMENTS
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This work was partially supported by JSPS KAKENHI (nos.
JP22390002, JP24106731, JP16H01157, JP26293004,
JP17K14449, JP18H04418, JP18H04624, and JP18H02557),
the Asahi Glass Foundation (T.I.), and the MEXT Project of
“Integrated Research Consortium on Chemical Sciences”
(T.I.). This work was performed under the Cooperative
Research Program of “Network Joint Research Center for
Materials and Devices.”
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(11) Pietruszka, J.; Schone, N. New 1,3-Disubstituted Enantiomeri-
cally Pure Allylboronic Esters by Johnson Rearrangement of Boron-
Substituted Allyl Alcohols. Eur. J. Org. Chem. 2004, 2004, 5011−5019.
(12) Faunce, J. A.; Grisso, B. A.; Mackenzie, P. B. Enantioselective
Aldol Chemistry via Alkyl Enol Ethers. Scope of the Lewis Acid
Catalyzed Condensation of Optically Active Trimethylsilyl and
Methyl 2-[(E)-1-Alkenyloxy]Ethanoates with Acetals. J. Am. Chem.
Soc. 1991, 113, 3418−3426.
REFERENCES
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(1) For reviews on ynolates: (a) Shindo, M. Synthetic Uses of
Ynolates. Tetrahedron 2007, 63, 10−36. (b) Shindo, M.; Matsumoto,
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(5) For selected examples: (a) Shindo, M.; Sato, Y.; Shishido, K. A
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