Solution Structures of Hauser Base (Pr2NMgCI)-Pr-i and Turbo-Hauser Base (Pr2NMgCl)-Pr-i center dot LiCI in THE and the Influence of LiCI on the Schlenk-Equilibrium

Abstract

Grignard reagents that are at the simplest level described as "RMgX" (where R is an organic substituent and X a halide) are one of the most widely utilized classes of synthetic reagents. Lately, especially Grignard reagents with amido ligands of the type R1R2NMgX, so-called Hauser bases, and their Turbo analogue R1R2NMgX center dot LiCI play an outranging role in modern synthetic chemistry. However, because of their complex solution behavior, where Schlenk-type equilibria are involved, very little is known about their structure in solution. Especially the impact of LiCl on the Schlenk-equilibrium was still obscured by complexity and limited analytical access. Herein, we present unprecedented insights into the solution structure of the Hauser base (Pr2NMgCl)-Pr-i 1 and the Turbo -Hauser base (Pr2NMgCl)-Pr-i center dot LiCl 2 at various temperatures in THE-d(8) solution by employing a newly elaborated diffusion ordered spectroscopy (DOSY) NMR method hand-in-hand with theoretical calculations.