Synlett

LaCl3× 2LiCl-Catalyzed Addition of Grignard Reagents to Ketones

A Metzger, A Gavryushin, P Knochel

Index: Metzger, Albrecht; Gavryushin, Andrei; Knochel, Paul Synlett, 2009 , # 9 p. 1433 - 1436

Full Text: HTML

Citation Number: 0

Abstract

Such 1,2-addition is often complicated if sterically hindered or unreactive Grignard reagents are used. In these cases, several side reactions such as enolization (leading to 4) or β-hydride transfer (leading to secondary alcohols 5) are observed. The formation of byproducts 4 and 5 can be considerably reduced by using a Lewis acid activation of the ketone 2. Lanthanide halides such as CeCl 3 introduced by Imamoto have proven to be especially effective. [²] ...