Synthetic methods Part (II): oxidation and reduction methods

Abstract

This Report highlights advances in some of the most commonly used oxidation and reduction reactions, focusing on the literature from 2010. The review is subdivided in a similar fashion to the authors' previous reviews in this area (S. E. Lewis, Annu. Rep. Prog. Chem., Sect. B: Org. Chem., 2010, ; S. E. Lewis, Annu. Rep. Prog. Chem., Sect. B: Org. Chem., 2009, ). Several standout advances have been reported. In the field of oxidation, Yamamoto has reported methods for the reliable enantioselective epoxidation of homoallylic and bishomoallylic alcohols (H. Yamamoto, J. Am. Chem. Soc., 2010, ) an area hitherto underdeveloped in comparison with allylic alcohol oxidation. Tomkinson has developed a dihydroxylation of alkenes which employs a readily prepared, stable malonyl peroxide as oxidant, the significance of which is highlighted by the lack of other metal-free methods to effect the corresponding transformation (N. C. O. Tomkinson et al., J. Am. Chem. Soc., 2010, ). In the field of reduction, Tsuji has reported a catalytic system that is particularly effective for the reduction of highly hindered ketones and even exhibits selectivity for more hindered ketones over less hindered ones (Y. Tsuji et al., Angew. Chem., Int. Ed., 2010, ). Also in the area of ketone reduction, Matsuo has demonstrated reduction of ketones by 1,3-diols in an unusual metal-free process catalysed by a sulfonic acid; high levels of stereoinduction are achieved when a homochiral diol is employed as reductant (J.-I. Matsuo et al., Tetrahedron, 2011, ; J.-I. Matsuo et al., Org. Lett., 2010, ).