Cobalt-catalyzed three-component assembly of aromatic oximes with substituted dienes and formaldehyde.

A cobalt-catalyzed three-component assembly of substituted aryl oximes with dienes and formaldehyde C-H bond activation is described. This protocol affords highly regio- and chemoselective substituted homoallylic alcohols with moderate-to-excellent yields. The scope of this protocol has been extensively explored with various substituted aryl ketoximes and aldoximes. Butadiene and internally substituted dienes are also well compatible for this transformation. A plausible reaction mechanism is proposed to account for the present reaction and is supported by deuterium labeling studies.