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Unusual mechanisms in Claisen rearrangements: an ionic fragmentation leading to a meta-selective rearrangement.

ABSTRACT: A mechanistic investigation of the acid-catalysed redox-neutral oxoarylation reaction of ynamides using electrospray ionisation mass-spectrometry (ESI-MS) and quantum chemical calculations (DFT and MP2) is presented. This study reveals the diversity of pathways and products available from an otherwise deceptively simple-looking, classical transformation: fragmentation, an unusual meta-arylation and competing ?-carbonyl cation pathways are some of the alternatives unveiled by ESI-MS and mechanistic experiments. Detailed calculations explain the observed trends and rationalise the results.

SUBMITTER: Maryasin B

PROVIDER: S-EPMC5941282 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature

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Unusual mechanisms in Claisen rearrangements: an ionic fragmentation leading to a <i>meta</i>-selective rearrangement.

Maryasin Boris B Kaldre Dainis D Galaverna Renan R Klose Immo I Ruider Stefan S Drescher Martina M Kählig Hanspeter H González Leticia L Eberlin Marcos N MN Jurberg Igor D ID Maulide Nuno N

Chemical science 20180410 17

A mechanistic investigation of the acid-catalysed redox-neutral oxoarylation reaction of ynamides using electrospray ionisation mass-spectrometry (ESI-MS) and quantum chemical calculations (DFT and MP2) is presented. This study reveals the diversity of pathways and products available from an otherwise deceptively simple-looking, classical transformation: fragmentation, an unusual <i>meta</i>-arylation and competing α-carbonyl cation pathways are some of the alternatives unveiled by ESI-MS and me ...[more]

PMID: 29780542

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