Cycloaddition of group VIII metal-dioxygen complexes to electrophilic olefins

Pd-mediated epoxidation of olefins

“…In 1975, Sheldon and van Doorn reported the cycloaddition of (Ph 3 P) 2 PdO 2 to 2-(propan-2-ylidene)malononitrile, and the acidic cleavage of the resulting cyclic peroxy-adduct into a 1:2 mixture of olefin and epoxide (Scheme 1) [20].…”

“…The phenol-mediated epoxidation of alkenes by H 2 O 2 disclosed by Jacobs et al [73] rationalize the epoxidation without metal, while the known instability of 2-(3-methyloxiran-2-yl)phenol [74] explains our inability to isolate this particular epoxide. (20) Che et al investigated the enantioselective epoxidation of styrenes with t-BuOOH and chiral binaphthyl Schiff base complexes of palladium. Efficiencies, selectivities and enantioselectivities depended markedly on the substitution of the aryl group (Eq.…”

Peroxometal complexes

“…However, the isolation with some metals and some substrates of peroxocyclic intemediates such as 21 and 22 does not ~~ allow one to rule out this hypothesis, at least for some metal-substrate pairs [95,96]. It should be noted however that species such as 21 and 22 are formed by in-~~ ~~ teraction of a nucleophilic peroxo complex with an electrophilic substrate…”

Peroxo Compounds, Inorganic

“…The physical properties of KO 2 are summarized in [28], [29]. It is used as an oxygen generator and carbon dioxide absorber in breathing apparatus and gas masks.…”