Synthesis 2003(15): 2275-2288  
DOI: 10.1055/s-2003-42417
REVIEW
© Georg Thieme Verlag Stuttgart · New York

Ynolates as Functional Carbanions

Mitsuru Shindo*a,b
a Institute for Medicinal Resources, University of Tokushima, Sho-machi 1, Tokushima 770-8505, Japan
Fax: +81(88)6337294.; e-Mail: shindo@ph2.tokushima-u.ac.jp;
b PRESTO Japan Science and Technology Corporation, Kawaguchi, Saitama 332-0072, Japan
Further Information

Publication History

Received 14 April 2003
Publication Date:
07 October 2003 (online)

Abstract

Ynolates are multifunctional carbanions bearing a triple bond. Due to the difficulty in synthesizing them, their chemistry has remained relatively unexplored. However, since the recent publication of several new methodologies for the preparation of these interesting compounds, the versatility of ynolates in synthetic organic chemistry has been recognized, and new aspects of ynolate chemistry, e.g., tandem reactions, cycloadditions, olefinations of carbonyl compounds, are being developed.

  • 1 Introduction.

  • 2 Synthesis of Ynolates

  • 2.1 Fragmentation of Isoxazolyl Lithium

  • 2.2 Metalation of Silylketenes

  • 2.3 Rearrangement of α-Keto Dianions

  • 2.4 Oxidation of Terminal Alkynes

  • 2.5 Flash Photolysis

  • 2.6 Silyl Ynolates from α-Diazoacyllithium

  • 2.7 Cleavage of Ester Dianions

  • 2.8 Ynolate Dianions

  • 3 Spectroscopic Analysis of Ynolates

  • 4 Reactions of Ynolates

  • 4.1 [2+2] Cycloaddition with Aldehydes and Ketones

  • 4.1.1 β-Lactone Enolates

  • 4.1.2 Tandem Reactions Leading to Multisubstituted Carbocycles

  • 4.2 [2+2] Cycloaddition with C=N Bond

  • 4.3 [3+2] Cycloaddition

  • 4.3.1 Anionic Inverse Electron-Demand [3+2] Cycloaddition with Nitrones

  • 4.3.2 Formal [3+2] Cycloaddition with Oxiranes and Aziridines

  • 4.4 [4+2] Cycloaddition

  • 4.5 Olefination of Carbonyl Compounds

  • 4.5.1 Olefination of Aldehydes and Ketones

  • 4.5.2 Stereoelectronic Effect

  • 4.5.3 Olefination of Acylsilanes

  • 4.5.4 Olefination of Aldimines

  • 4.6 Reduction of Ynolates

  • 5 Silyl Ynol Ethers

  • 5.1 Preparation of Silyl Ynol Ethers

  • 5.2 Reactions of Silyl Ynol Ethers

  • 6 Conclusion

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Manuscript in preparation.