ZnCl₂-Catalyzed Addition of Grignard Reagents to Ketones and Aldimines

Significance

The authors developed a simple inexpensive alternative to the known methods for the facilitation of the reaction between a carbonyl compound (or an imine) and a Grignard reagent. In some cases, the yields are increased from 20% to more than 80%. One of the features of the process is the suppression of the competitive reduction in the case of secondary alkyl magnesium reagents. ZnCl₂ is much cheaper than other suitable reagents like LnCl₃ and can be used in catalytic amounts (10 mol%). The method looks especially suitable for large-scale applications.