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Updated: Jun 30, 2026

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
Published on: August 2, 2012
Anionic Snieckus-Fries rearrangement: solvent effects and role of mixed aggregates
Jason C Riggs1, Kanwal J Singh, Ma Yun
1Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, USA.
Abstract:
Lithiated aryl carbamates (ArLi) bearing methoxy or fluoro substituents in the meta position are generated from lithium diisopropylamide (LDA) in THF, n-BuOMe, Me2NEt, dimethoxyethane (DME), N,N,N',N'-tetramethylethylenediamine (TMEDA), N,N,N',N'-tetramethylcyclohexanediamine (TMCDA), and hexamethylphosphoramide (HMPA). The aryllithiums are shown with (6)Li, (13)C, and (15)N NMR spectroscopies to be monomers, ArLi-LDA mixed dimers, and ArLi-LDA mixed trimers, depending on the choice of solvent. Subsequent Snieckus-Fries rearrangements afford ArOLi-LDA mixed dimers and trimers of the resulting phenolates. Rate studies of the rearrangement implicate mechanisms based on monomers, mixed dimers, and mixed trimers.
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