Journal article
Brønsted acid catalyzed intramolecular benzylic cyclizations of alkylpyridines
Organic & biomolecular chemistry, Vol.12(7), pp.1090-1099
02/21/2014
DOI: 10.1039/c3ob42039f
PMID: 24382575
Abstract
Aldehyde and ketone electrophiles incorporated into the side chains of 2- and 4-alkylpyridines participate in intramolecular aldol-like condensations with pyridine benzylic carbons in the presence of Brønsted acid catalysts. Pyridines featuring β-ketoamide side chains undergo cyclization in the presence of 10 mol% TfOH to afford pyridyl-substituted hydroxy lactams in good yield. These products were found to be resistant to further dehydration under a variety of conditions, however treatment with thionyl chloride elicited an unusual dehydration/oxidation reaction sequence. In contrast, acid-catalyzed cyclization of pyridines tethered to aliphatic aldehydes with amine linkers gives pyridyl-substituted dehydro-piperidine products. Similarly, intramolecular condensation of salicylaldehyde- and salicylketone-substituted pyridines affords pyridyl-substituted benzofurans.
Details
- Title: Subtitle
- Brønsted acid catalyzed intramolecular benzylic cyclizations of alkylpyridines
- Creators
- Ashabha I Lansakara - Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, USA. chris-pigge@uiowa.eduDaniel P FarrellF Christopher Pigge
- Resource Type
- Journal article
- Publication Details
- Organic & biomolecular chemistry, Vol.12(7), pp.1090-1099
- Publisher
- England
- DOI
- 10.1039/c3ob42039f
- PMID
- 24382575
- ISSN
- 1477-0520
- eISSN
- 1477-0539
- Grant note
- DOI: 10.13039/100000001, name: National Science Foundation, award: CHE-1265488
- Language
- English
- Date published
- 02/21/2014
- Academic Unit
- Radiology; Chemistry
- Record Identifier
- 9983985878302771
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