SYNTHESIS OF KETONES BEARING β-QUATERNARY AND TERTIARY CENTERS THROUGH UMPOLUNG α-ALLYLATION

The inherent difficulty of making C-C bonds to quaternary or tertiary centers in the β-position of ketones through classical alkylation has led to the development of innovative multi-step methods of achieving this transformation.^1,2 We have developed a novel solution to this challenge that relies on the umpolung of ketone enolates through the action of an oxidizing agent and subsequent allylation with substituted allyl-silanes.^3,4 While iodoenolates have been proposed as reaction intermediates for decades they are too unstable to characterize.

References

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[2] C. Li, B. Breit, J. Am. Chem. Soc. 2014, 136, 862

[3] O. Svetlana Shneider, E. Pisarevsky, P. Fristrup, A. M. Szpilman* Org. Lett. 2015, 17, 282.

[4] R. Caple, N.S. Zefirov et al., J.Org.Chem., 1989, 54, 2605