Diastereoselective Alkylation of β-Amino Esters:  Structural and Rate Studies Reveal Alkylations of Hexameric Lithium Enolates Anne J. McNeil Gilman E. S. Toombes Sol M. Gruner Emil Lobkovsky David B. Collum Sithamalli V. Chandramouli Benoit J. Vanasse Timothy A. Ayers 10.1021/ja045144i.s001 https://acs.figshare.com/articles/journal_contribution/Diastereoselective_Alkylation_of_Amino_Esters_Structural_and_Rate_Studies_Reveal_Alkylations_of_Hexameric_Lithium_Enolates/3311161 Alkylation of β-amino ester enolates proceeds with high diastereoselectivity. Single crystal, powder, and solution X-ray diffraction studies of the enolate show that the racemic enolate forms prismatic hexamers. <sup>6</sup>Li NMR spectroscopic studies on partially racemic enolates reveal complex mixtures of homo- and heterochiral hexamers. An implicit fit of the aggregate populations to the Boltzmann distribution provides the free energy differences and equilibrium constants for the ensemble. Rate studies show that enolate alkylation occurs directly from the hexamer with participation by THF. A mechanism based on the alkylation of a ladder-like aggregate is proposed. 2004-12-22 00:00:00 Single crystal rate studies show THF 6 Li NMR spectroscopic studies enolate show heterochiral hexamers racemic enolate forms prismatic hexamers racemic enolates energy differences ester enolates proceeds Boltzmann distribution Diastereoselective Alkylation Rate Studies Reveal Alkylations enolate alkylation equilibrium constants Hexameric Lithium Enolates Alkylation