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Lewis Acid Catalyzed Transfer Hydromethallylation for the Construction of Quaternary Carbon Centers.

ABSTRACT: The design and gram-scale synthesis of a cyclohexa-1,4-diene-based surrogate of isobutene gas is reported. Using the highly electron-deficient Lewis acid B(C6 F5 )3 , application of this surrogate in the hydromethallylation of electron-rich styrene derivatives provided sterically congested quaternary carbon centers. The reaction proceeds by C(sp3 )-C(sp3 ) bond formation at a tertiary carbenium ion that is generated by alkene protonation. The possibility of two concurrent mechanisms is proposed on the basis of mechanistic experiments using a deuterated surrogate.

SUBMITTER: Walker JCL

PROVIDER: S-EPMC6856816 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature

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Lewis Acid Catalyzed Transfer Hydromethallylation for the Construction of Quaternary Carbon Centers.

Walker Johannes C L JCL Oestreich Martin M

Angewandte Chemie (International ed. in English) 20190912 43

The design and gram-scale synthesis of a cyclohexa-1,4-diene-based surrogate of isobutene gas is reported. Using the highly electron-deficient Lewis acid B(C6 F5 )3 , application of this surrogate in the hydromethallylation of electron-rich styrene derivatives provided sterically congested quaternary carbon centers. The reaction proceeds by C(sp3 )-C(sp3 ) bond formation at a tertiary carbenium ion that is generated by alkene protonation. Th ...[more]

PMID: 31449730

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