Chemistry Reference
In-Depth Information
Monomer
NO + R
2
NH
[HR
2
NNO]
(4.27)
k
1
r.d.s.
(4.28)
NO
+
[HR
2
NNO]
HR
2
NN
2
O
2
(4.29)
HR
2
NN
2
O
2
R
2
NH
[R
2
NN
2
O
2
]
−
[R
2
NH]
+
+
4.9.5 General organic reactions
An important reason why the organic chemistry of nitric oxide is so sparse is that many of the products are
complex mixtures of salts. These frequently require careful recrystallization steps and exacting control of
conditions to give clean, reproducible products. There is a wealth of new chemistry to be discovered from
the addition reactions of nitric oxide, with a particularly telling example being the range of salts which
result from the diazeniumdiolation of ketones.
182
Pressure, temperature, alkali metal, and stoichiometry
are all critical parameters which need to be controlled in this chemistry. A particularly complex example
of this chemistry is the diazeniumdiolation of benzylcyanide, which gives either bis diazeniumdiolates,
a 1,2,3-oxadiazole, or an oxime (Equation 4.30).
178,183,184
Depending upon conditions of temperature,
stoichiometry, pressure, and alkali metal, it is possible to isolate the oxime or the dianion in high yields.
178
Recently, the reactions of nitric oxide with organic radicals has been reviewed.
185
−
O
O
bisdiazenium-
diolation
−
O
N
N
N
N
C
OMe
Ph
C
55 %
N
NO
2 atm, r.
t.
H
substrate
oxidation
H
+
−
NOH
CH
(4.30)
C
5%
PhCH
2
CN
Ph
Ph
C
+H
+
MeOH/MeO
−
C
N
N
O
N
12 %
N
cyclization
Ph
C
O
C
H
2
N
4.9.6 Reactions with other nucleophiles
The range of nucleophiles which give stable diazeniumdiolates from the addition of nitric oxide (Figure 4.8
and Equation 4.22) is surprisingly small. Hydrides, cyanide, most tertiary phosphines, tertiary amines,
azide, and ammonia all fail to return diazeniumdiolates from the addition of nitric oxide. The phosphorus
adducts, if formed, rapidly eliminate nitrous oxide and form the phosphine oxide. Apart from Pelouze's
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