NMR studies on mixed trimer complex of n-BuLi and chiral lithium amide

ORGN 172

Jia Liu, Deyu Li, Deyu_Li@Brown.edu, and Paul G. Williard, paul_williard@brown.edu. Department of Chemistry, Brown University, 324 Brook Street, Box H, Brown University, Providence, RI 02912
A lithium amide and n-butyl lithium 2:1 aggregate was crystallized from hydrocarbon solvent in 1997. In order to investigate its solution structure, a series of NMR studies were carried out. DOSY confirmed this exact structure in deuterated toluene. Low temperature NMR studies illustrated that the trimeric aggregate is the major species in solution. Solutions containing different ratios of lithium amide and n-butyl lithium were prepared and their DOSY spectra indicated that the 2:1 aggregate is the favored mixed aggregate. These NMR results also agree with the decent enantiomeric excess when the mix aggregate adds on aldehydes.

 

Asymmetric Reactions and Syntheses, Metal-Mediated Reactions, Combinatorial, Parallel, and Solid-Phase Chemistry
8:00 PM-10:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster

Division of Organic Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006