In the presence of a bis(1,3-diketonato)nickel(II) complex, various olefins are directly monooxygenated into the corresponding epoxides on treatment with atmospheric pressure of oxygen or air and aldehydes. Especially, it is noted that bis[1,3-bis(p-methoxyphenyl)-1,3-propanedionato]nickel(II) behaves as an excellent catalyst in the present epoxidation.
A Novel Method for the Preparation of Acid-Sensitive Epoxides from Olefins with the Combined Use of Molecular Oxygen and Aldoacetal Catalyzed by a Cobalt(II) Complex
An efficient synthesis of acid-sensitive epoxides, such as chromene oxide or epoxide of γ,δ-unsaturated alcohol, was successfully achieved by the oxygenation of corresponding olefins with the combined use of an atmospheric pressure of molecular oxygen and aldoacetal catalyzed by a cobalt(II) complex coordinated with the 1,3-diketone ligand. The reactions proceeded under mild and neutral conditions
Tris[1,3-bis(p-methoxyphenyl)-1,3-propanedionato]iron(III) (Fe(dmp)3) was found to be an excellent catalyst for oxygenation of a number of olefinic compounds including styrene analogues and olefinic alcohols into the corresponding epoxides in good to quantitative yields with combined use of molecular oxygen and an aldehyde at room temperature.
In the presence of a catalytic amount of cobalt(II)-Schiff base complexes, various olefins are smoothly oxygenated into the corresponding epoxides in good to high yields by combined use of an atmospheric pressure of oxygen (oxidant) and cyclic ketones (reductant), such as 2-methylcyclohexanone, under mild conditions.
In the presence of a catalytic amount of a bis(1,3-diketonato)nickel(II) complex, trisubstituted and exo-terminal olefins or norbornene analogues are smoothly monooxygenated into the corresponding epoxides in high to quantitative yields on treatment with aldehyde under an atmospheric pressure of oxygen at room temperature.