Copper-Catalyzed Asymmetric Allylic Alkylation Using Grignard Reagents

Significance

S_N2′-type substitution on allylic systems can provide an attractive route to chiral molecules. The authors report a Cu-TaniaPhos system which catalyzes allylic substitutions of allylic bromides using Grignard reagents to provide a terminal olefin. Various linear Grignard reagents could be introduced onto functionalized substrates in high yield and ee with superb regioselectivity. The utility of this transformation is demonstrated through functionalization of the newly formed terminal olefin to provide various optically active bifunctional molecules.