El-Hiti, Gamal, Smith, Keith, Hegazy, Amany Saber, Shalabi, Ahmed Fekri and Kariuki, Benson ![]() |
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Abstract
Directed lithiation of various substituted benzylamines takes different courses depending on the substituents at nitrogen and on the aryl ring and/or the nature of the alkyllithiums. Lithiation of N-benzylpivalamide with t-BuLi gives a mixture of ring (2-position) and side-chain lithiated species, but the 2-lithiated isomer can be obtained cleanly via bromine-lithium exchange of N-(2-bromobenzyl)pivalamide. N'-Benzyl-N,N-dimethylurea, N'-(4-substituted benzyl)-N,N-dimethylureas and N-(4-substituted benzyl)pivalamides give 2-lithiated derivatives directly with t-BuLi at -78 °C. By contrast, lithiation of N-(2-methoxybenzyl)pivalamide occurs at the 6-position, ortho- to the methoxy group, while lithiation of N'-(2-methoxybenzyl)-N,N-dimethylurea gives a mixture of 2- and 6-lithiated species. All organolithiums are converted in high yields to their corresponding substitution products on reactions with various electrophiles.
Item Type: | Article |
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Status: | Published |
Schools: | Chemistry |
Subjects: | Q Science > QD Chemistry |
Uncontrolled Keywords: | Directed ortho-lithiation; electrophilic substitution; substituted benzylamines; synthesis; side-chain lithiation |
Additional Information: | Part (xiv): General Papers. Graphical abstracts |
Publisher: | Arkat USA Inc |
ISSN: | 1551-7004 |
Date of First Compliant Deposit: | 30 March 2016 |
Last Modified: | 16 May 2023 20:42 |
URI: | https://orca.cardiff.ac.uk/id/eprint/12725 |
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