Nuclear Magnetic Resonance Spectroscopy. The Configurational Stability of Primary Grignard Reagents. Structure and Medium Effects

Qualitative and semiquantitative examination of the temperature dependence of the RCH_2-Mg proton n.m.r. spectra of several Grignard reagents indicates that the rate of inversion at this center is relatively insensitive to the structure of the group R. Secondary Grignard reagents invert much more slowly, if at all. The dependence of the inversion rate of the primary organometallic compounds on solvent character and on added salts suggests that inversion proceeds by means of a mechanism having kinetic order greater than one