Module I Oxidation Reactions - NPTel

NPTEL – Chemistry – Reagents and Organic reactions
O 2N
AcHN
Mechanism
O Me
Me
Katsuki catalyst (3)
PhIO
O 2N
AcHN
Scheme 4
78%
ee 96%
O Me
Me
N N
Mn
O O
Me Ph
Me
H
Me Ph H
Me
Katsuki catalyst (3)
The mechanism of this reaction is not fully understood but it has been proposed
that the oxidant oxidizes Mn(III)-salen to Mn(IV)-salen, which oxidizes the alkene
(Scheme 5). There are three possible reaction pathways such as concerted,
metallo oxetane and radical pathway but the most accepted one is the concerted
pathway.
N N
Mn
O Cl O
NaOCl
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O
N O
Mn
N
O Cl O
Active catalyst
PF 6 -
N O
Mn
N
O Cl O