Catalytic cascade synthesis of cyanohydrin esters via water/O 2 -induced cyanide transfer from K 3 Fe(CN) 6 .

The copper-catalyzed α-oxygenation of aryl benzyl ketones is merged with a unique water/O 2 -induced release of cyanide ions from K 3 Fe(CN) 6 and a benzil-cyanide reaction. This strategy gives expedient access to cyanohydrin esters starting directly from broadly accessible aryl benzyl ketones. The cyanide release strategy was further integrated with a copper catalyzed oxygenation-decarbonylation sequence to produce cyanohydrin esters from 1,3-diketones.