Chemistry Reference
In-Depth Information
The complete reaction can be illustrated as follows:
R
R
N
N
O
O
O
Zn
O
O
R
O
N
R
O
R
N
N
N
O
O
Zn
O
O
O
O
O
O
O
O
O
N
O
O
R
R
R
O
H
R
O
N
N
R
N
O
N
NZn
n
O
O
O
O
O
O
H
O
O
O
H
2
0
O
H
R
O
N
NH
2
HO
N
n
O
H
R
-carboxyanhydrides
[
156
]. The mechanism of the reaction was postulated by Freireich, Gertner and Zilkha [
156
] to consist
of addition of the organotin compound to the anhydride and formation of organotin carbamate. It
subsequently decarboxylates and leaves an active -N-Sn- group that adds to another molecule of
Organotin compounds are also active as catalysts in the polymerizations of
N
N
-
carboxyanhydride. This process is repeated in every step of the propagation [
156
]:
H
O
H
O
N
(C
4
H
9
)
3
NO
Sn
OCH
3
O
(C
4
H
9
)
3
+
CH
3
O
R
Sn
O
R
O
O
H
-CO
2
(C
4
H
9
)
3
N
CH
3
O
Sn
R
