alpha-Deprotonation of a beta-shielded acrylamide creates a distorted lithium 1-aminoallen-1-olate

Knorr, Rudolf; Schmidt, Barbara und Roman, Therese von (2019): alpha-Deprotonation of a beta-shielded acrylamide creates a distorted lithium 1-aminoallen-1-olate. In: Journal of Organometallic Chemistry, Vol. 894: pp. 78-83

Abstract

The beta-shielded acrylamide N,N-diisopropyl-alpha-(1,1,3,3-tetramethylindan-2-ylidene) acet-amide was prepared through ketone addition of an alpha-lithiated acetamide, followed by H2O elimination. Its alpha-deprotonation by n-butyllithium occurred readily in THF without any tendency towards addition reactions at C=O or C-beta. The resultant single crystals of a dimeric lithio derivative had triple Li-O coordination and a weakly bonding, ion-pair type Li-C(alpha) relationship. In tert-butyl methyl ether as the solvent, up to seven pairs of diastereotopic nuclei (both H-1 and C-13) established a C-S-symmetric lithium 1-aminoallen-1-olate structure that is ascribed to either a thermal ground state or a very rapid (on the NMR time scales) oscillation between two chiral ground states that may resemble the solid-state structure. (c) 2019 Elsevier B.V. All rights reserved.

• Item Type: Journal article
• Faculties: Chemistry and Pharmacy > Department of Chemistry
• Subjects: 500 Science > 540 Chemistry
• ISSN: 0022-328X
• Language: English