Catalytic oxidations using cobalt(II) complexes - Advances in Catalytic Activation of Dioxygen by Metal Complexes - page 280

at the cobalt complex. The experimental results are consistent with chain
reactions involving the free radicals shown in Figure 19.
The Jacobsen-type manganese complex gives lower yields of epoxides
(40-60%), but for 2,2-dimethylchromene and styrene the epoxides are
optically active (12-60% ee).

3.10 Primary amines

Bis[3 -(salicylideneimino)propyl] methylaminecobalt(II) (CoSMDPT)
catalyzes the oxidation of primary amines with dioxygen 57 . Benzylamine, 4-
methyl-benzylamine and 4-methoxybenzylamine gave aldehyde intermedi-
ates, which were converted to Schiff bases with the starting amines. The
oxidation of 1-phenyl-ethylamine gave 2,4,6-triphenyl-3-aza-3,5-heptadiene
via disproportionation of the intermediate Schiff base.

4. OXIDATIONS CATALYZED BY COBALOXIMES

The cobaloxime(II) derivatives where H 2 dmg is
dimethylglyoxime, and L is py and catalyze the oxidative
dehydrogenations (Figure 20) and oxygen insertions of some organic sub-
strates at room temperature and atmospheric dioxygen pressure 58-61 .

where

Q - p -benzoquinone,
AB - azobenzene.

In the following discussion and stand for cobaloxime(II) and

cobaloxime(III), i.e. and respectively, and

L is py, or
In the reaction mechanisms proposed for cobaloxime-catalyzed
oxidations, the superoxocobaloxime(III),

formed directly from

cobaloxime(II) and is the key intermediate. It is also the source of several