Stereoselective allylboration using (B)-γ- alkoxyallyldiisopinocampheylboranes: Highly selective reactions for organic synthesis

This review describes the synthesis of novel alkoxyallylborane reagents derived from α-pinene and their applications in stereoselective total synthesis of natural products. These reagents can be conveniently prepared and react readily with a wide variety of aldehydes and imines to provide the corresponding α-alkoxy substituted homoallylic alcohols/amines respectively. The (Z)-γ-alkoxyallylborane reagents provide 1,2-syn α-alkoxy homoallylic alcohols/amines while the corresponding (E)-γ-alkoxyallylborane reagents furnish 1,2-anti products exclusively in very high enantioselectivities.