Toward Solution-State Structure. A6Li,1H HOESY NMR, X-ray Diffraction, Semiempirical (PM3, MNDO), and ab Initio Computational Study of a Chiral Lithium Amide

Computational studies of a chiral lithium amide (lithium (2-methoxy-( R )-1-phenylethyl)(( S )-1-phenylethyl)amide, 3 ) using the solid-state structure as a reference geometry showed that there were only small differences between the X-ray and ab initio and PM3 calculated structures. Furthermore, we have shown that reference distances from either X-ray or ab initio/PM3 can be used for the calculation of Li−H distances using Li−H NOE data. The calculations of Li−H distances using HOESY buildup rates showed that the solution structure of 3 ·THF is similar to the structure obtained in the gas phase (calculated) and in the solid phase (X-ray). Small variations of ±0.2 Å were observed between X-ray/ab initio and NOE data for distances less than 4 Å.