Excellent yields and enantioselectivities can be achieved in the molybdenum–bishydroxamic acid catalyzed asymmetric oxidation of olefins in air at room temperature with an achiral oxidant (see scheme; acac=acetylacetonate). A range of terminal, cis‐, and trisubstituted olefins can be used as the substrate. Furthermore, when there are multiple double bonds, the most electron‐rich is oxidized.

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In this article, we describe the development and preliminary results of our new designed C(2)-symmetric bis-hydroxamic acid (BHA) ligands and the application of the new ligands for vanadium-catalyzed asymmetric epoxidation of allylic alcohols as well as homoallylic alcohols. From this success we demonstrate the versatile nature of BHA in the molybdenum catalyzed asymmetric oxidation of unfunctionalized olefins and sulfides.

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In investigations aimed at exploring the potential of disubstituted allenes in stereoselective synthesis, we report studies that explore the reductive cross-coupling reaction of vinylsilanes with a range of substituted allenes. Regiochemical control is attained by employing allenic alkoxides, where the proximal heteroatom dictates the site-selectivity in a process that proceeds by net formal metallo-[3,3] rearrangement (directed carbometalation/elimination). Stereoselectivity in these reactions is complex, with both the nature of allene substitution and relative stereochemistry of the substrate impacting the stereoselective generation of each alkene of a substituted 1,3-diene. 2009 Elsevier Ltd. All rights reserved.