title: The barrier to enantiomerization of N-Boc-2-lithiopyrrolidine: the effect of chiral and achiral diamines.
abstract: (-)-Sparteine and TMEDA dramatically lower both enthalpy and entropy of activation for the barrier to enantiomerization of N-Boc-2-lithiopyrrolidine in diethyl ether, whereas N,N'-diisopropylbispidine has little effect; the entropy of activation for enantiomerization is zero in the presence of TMEDA and slightly negative in the presence of sparteine; these data suggest a subtle change in mechanism of enantiomerization in the presence of TMEDA and sparteine.
authors.affiliation: Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.
authors.forename: Taher I
authors.initials: TI
authors.lastname: Yousaf
authors.forename: Roger L
authors.initials: RL
authors.lastname: Williams
authors.forename: Iain
authors.initials: I
authors.lastname: Coldham
authors.forename: Robert E
authors.initials: RE
authors.lastname: Gawley