Takeda Olefination

16 March, 2015 / by SK / in Reactions

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General Characteristics

The olefination of thioacetals via generation of organotitanium intermediates using divalent titanocene reagents is known as the Takeda olefination.

The titanocene reagent needs to be prepared freshly for the reaction. Thioacetal-protected carbonyl compounds can be easily prepared. Compared with analogous systems such as the Tebbe, the Petasis, and the Takai-Lombardo reactions, the Takeda reaction has a wider substrate scope.

General References

Horikawa, Y.; Watanabe, M.; Fujiwara, T.; Takeda, T. J. Am. Chem. Soc. 1997, 119, 1127. DOI: 10.1021/ja962240d

Rahim, M. A.; Fujiwara, T.; Takeda, T. Tetrahedron 2000, 56, 763. doi:10.1016/S0040-4020(99)01091-1

Rahim, M. A.; Sasaki, H.; Saito, J.; Fujiwara, T.; Takeda, T. Chem. Commun. 2001, 625. DOI: 10.1039/B010156G

Hartley, R. C.; McKiernan, G. J. JCS Perkin Trans. 1 2002, 2763. doi: 10.1039/B009709H

Reaction Mechanism

Examples

An example as a key step in ciquatoxin synthesis.^[1]

Total synthesis of alstoscholarine.^[2]

Experimental Procedure
Experimental Tips
References

[1] Uehara, H.; Oishi, T.; Inoue, M.; Shoji, M.; Nagumo, Y.; Kosaka, M.; Brazidec, J.-Y.; Hirama, M. Tetrahedron 2002, 58, 6493. doi:10.1016/S0040-4020(02)00660-9
[2] Gerfaud, T.; Xie, C.; Neuville, L.; Zhu, J. Angew. Chem. Int. Ed. 2011, 50, 3954. DOI: 10.1002/anie.201100257