Article ID Journal Published Year Pages File Type
1345539 Tetrahedron: Asymmetry 2013 6 Pages PDF
Abstract

The antipodes of lithium N-benzyl-N-(α-methylbenzyl)amide are highly efficient enantiopure ammonia equivalents for the asymmetric synthesis of β-amino acid derivatives via conjugate addition to α,β-unsaturated esters. 6Li and 15N NMR spectroscopic studies of doubly labelled 6lithium (S)-15N-benzyl-15N-(α-methylbenzyl)amide in THF at low temperature reveal the presence of lithium amide dimers as the only observable species. Either a monomeric or dimeric lithium amide reactive species can be accommodated within the transition state mnemonic for this class of conjugate addition reaction. This enantiopure lithium amide offers unique opportunities over achiral (e.g., lithium dibenzylamide) and C2-symmetric (e.g., lithium bis-N,N-α-methylbenzylamide) counterparts for further mechanistic study owing to the ready distinction of the various dimers formed.

Graphical abstract6Li and 15N NMR spectroscopic studies of doubly labelled 6lithium (S)-15N-benzyl-15N-(α-methylbenzyl)amide in THF at low temperature reveal the presence of lithium amide dimers as the only observable species.Figure optionsDownload full-size imageDownload as PowerPoint slide

Related Topics
Physical Sciences and Engineering Chemistry Inorganic Chemistry
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