Synfacts 2019; 15(12): 1428
DOI: 10.1055/s-0039-1691104
Organo- and Biocatalysis
© Georg Thieme Verlag Stuttgart · New York

Construction of Quaternary Carbon Centers by Lewis Acid Catalyzed Transfer Hydromethallylation

Contributor(s):
Benjamin List
,
Vikas Kumar Singh
Walker JC. L, Oestreich M. * Technische Universität, Berlin, Germany
Lewis Acid-Catalyzed Transfer Hydromethallylation for the Construction of Quaternary Carbon Centers.

Angew. Chem. Int. Ed. 2019;
58: 15386-15389
Further Information

Publication History

Publication Date:
18 November 2019 (online)

 

Significance

Walker and Oestreich report a ­cyclohexa-1,4-diene-based surrogate of isobutene gas for hydromethylallylation of electron-rich styrene derivatives to provide quaternary carbon centers by using a highly electron-deficient Lewis acid as a catalyst. Even though boron in a substrate or catalyst is not usually considered an organocatalyst, this transformation is of potential use.


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Comment

Whereas there is significant current interest in metal-mediated C(sp2)–C(sp3) couplings with quaternary carbon center generation, approaches that proceed through the more traditional acid-catalyzed protonation of olefins are currently less explored. The presented method enables the catalytic formation of sterically congested quaternary carbon centers by the formation of carbenium ions that have been formed by protonation of alkenes.


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