922177-75-1Relevant academic research and scientific papers
Deprotonation of β,β-disubstituted α,β-unsaturated amides -Mechanism and stereochemical consequences
Green, James R.,Majewski, Marek,Snieckus, Victor
, p. 1397 - 1410 (2006)
A detailed study of the lithium dialkylamide induced deprotonation of β,β-disubstituted α,β-unsaturated amides is presented. The preferential γ-Z-deprotonation and stereochemical outcome of substituents on the γ-Z carbon atom are rationalized in terms of a cyclic eight-membered transition state, which is supported by DFT calculations. Analogous deprotonations on cyclohexylidenecarboxamides reveal a delicate balance of the preference for the eight-membered cyclic transition state with the effects of existing substituents on the ring and the intervention of a twist-boat transition state.
