Superiority of Phosphate Ester as Leaving Group for Organocopper Reactions. Highly SN2′ -, (E)-, and Antiselective Alkylation of Allylic Alcohol Derivatives

All articles of this category Treatment of secondary allylic chlorides or allylic phosphates in tetrahydrofuran with prenyl Grignard reagent (3-methyl-2-butenylmagnesium chloride) in the presence of CuCN.2LiCl gave geraniol or farnesol derivatives with high S N 2′ selectivity. Phosphate leaving groups were highly trans -stereoselective for the formation of ( E , E )-farnesol derivatives. Furthermore, complete anti-S N 2′ selectivity was observed in the alkylation of optically active allylic phosphates. The present method appears to be an excellent carbon-carbon coupling reaction with regio-, ( E )-, and enantioselectivity.