A simple route to 1,4-addition reactions by Co-catalyzed reductive coupling of organic tosylates and triflates with activated alkenes.

An efficient Co-catalyzed 1,4-addition reaction of alkyl/aryl triflates and tosylates with activated alkenes is described. In this reaction, an air-stable cobalt(ii) complex, a mild reducing agent Zn and a simple proton source (HO) are used. A radical mechanism for the addition of alkyl tosylates to activated alkenes is likely involved.