[reaction: see text] The oxidation of olefins by chiral monometallic and bimetallic Pd(II)-Cu(II) catalysts in bromide-containing aqueous-THF reaction mixtures produced chiral 1,2-dibromides. With alpha-olefins, the ee's were about 95% while most of the internal alkenes gave somewhat lower enantioselectivities ( approximately 80%).

Chiral α-hydroxy ketones (acyloins) are important intermediates for the asymmetric synthesis of natural products, fine chemicals, and drugs. 1 For that reason, their enantioselective synthesis is of considerable interest and there have been a number of reports with various approaches to chiral α-hydroxy ketones. 2 One general approach involves the preparation of enolates or enol derivatives, 3 while another method involves catalytic asymmetric oxidation of (E)-enol phosphates by (salen) Mn(III) complexes. 4 A recent approach to chiral α-hydroxy ketones involves the reactions of tin enolates with nitrosobenzene. 5 Macmillan reported the direct proline-catalyzed oxyamination of aldehydes. 6

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