COBALT(II) CATALYZED REACTION OF ALKENES WITH ALIPHATIC-ALDEHYDES ANDMOLECULAR-OXYGEN - SCOPE AND MECHANISM

A variety of cobalt(II) complexes can be prepared using Schiff's bases derived from aromatic aldehydes and amines or alpha-aminoesters. Thes e complexes are versatile catalyst for the reaction between aliphatic aldehydes and various alkenes- The outcome of the reaction is controll ed by the electronic nature of the alkene as the electron deficient al kenes undergo oxidative addition of aldehydes followed by dioxygen inc orporation to yield 2-hydroxy(acyloxy)-4-oxoesters or nitriles whereas unactivated or electron rich alkenes afford the corresponding epoxide s. These reactions are proceeding via a radical pathway and a common a cylcobalt intermediate is proposed for the formation of 4 as well as t he epoxides 7.