Remote Lithiations of Carboxamides: The Manifestation of a Post-Complexation Proximity Effect (Homoenolate)

The remote metalations of tertiary amides, (beta) and (gamma) substituted with vinyl, phenyl and thiophenol groups, are reported. N,N-Diisopropyl-2-methylpent-4-enecarboxamide (59), N,N-diisopropyl-2-methyl-3-phenylpropanecarboxamide (139), N,N-diisopropyl-2-methyl-3-phenylthiopropanecarboxamide (174), N,N-diisopropyl-2-methyl-3-phenylthiobutanecarboxamide (176), N,N-diisopropyl-3-phenylthio-2-(phenylthiomethyl)propanecarboxamide (215) and N,N-diisopropyl-2-methyl-3-phenylthio-2-(phenylthiomethyl)butanecarboxamide (217), undergo deprotonation at the (beta) position upon reaction with sec-BuLi/TMEDA. The intermediate benzyl and thiomethylene anions react with a variety of electrophiles to yield (beta) substituted products. In the case of 217, metalation and electrophilic substitution occurs at a (beta) secondary carbon atom. The allylic alkyllithium generated undergoes electrophilic at the (beta) or (delta) position. Lithiation and substitution at the (gamma) position occurs upon treatment of N,N-diisopropyl-2-methyl-4-phenylthiobutanecarboxamide (193), with sec-BuLi/TMEDA, followed by an electrophile. The synthetic consequences of the metalations are discussed and demonstrated.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Hunter, James Edward

• Chemistry, Organic

Identifier

(UMI)AAI8623328

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/70327