1426401-75-3Relevant academic research and scientific papers
Azaaldol condensation of a lithium enolate solvated by N,N,N′, N′ -tetramethylethylenediamine: Dimer-based 1,2-addition to imines
De Vries, Timothy S.,Bruneau, Angela M.,Liou, Lara R.,Subramanian, Hariharaputhiran,Collum, David B.
, p. 4103 - 4109 (2013)
The lithium enolate of tert-amylacetate solvated by N,N,N′,N′- tetramethylethylenediamine (TMEDA) is shown to be a doubly chelated dimer. Adding the dimeric enolate to 4-fluorobenzaldehyde-N-phenylimine affords an N-lithiated β-amino ester shown to be monomeric using 6Li and 15N NMR spectroscopies. Rate studies using 19F NMR spectroscopy reveal reaction orders consistent with a transition structure of stoichiometry [(ROLi)2(TMEDA)2(imine)]?. Density functional theory computations explore several possible dimer-based transition structures with monodentate and bidentate coordination of TMEDA. Supporting rate studies using trans-N,N,N′,N′-1,2- tetramethylcyclohexanediamine showing analogous rates and rate law suggest that TMEDA is fully chelated.
