Chemistry Reference
In-Depth Information
O
O
CH
3
OH
S
NHOCH
3
N
1
S
O
O
O
h
v
-N
2
64d
1
61d
S
N
3
O
O
H
O
CH
3
OH
60d
N
S
OCH
3
N
S
O
O
65d
66d
SCHEME 12.30.
Photolysis of benzenesulfonyl azide
60d
in methanol.
133
in a mixture of 2-methylbutane and dichloromethane (1:1) gave
a mixture of four insertion products of
1
61b
Irradiation of
60b
H bonds of the former. The
selectivity of this nitrene for the tertiary, secondary, and primary C
into the C
H bonds was
found to be 9.6:4.2:1.
136a
Photolysis of
60b
in a mixture of ethanol and cyclohexane
was also performed, and the yields of
were found to be 14 and 35%,
respectively. From this data, the relative reactivity of O
62b
and
64b
H bond per cyclic C
H
bond was calculated to be 29.
136a
Alkanesulfonyl nitrenes (
61b,c
) were also generated by thermolysis of mesyl-
) azides.
136b
The singlet nitrenes
1
61b,c
(
60b
) and pentanesulfonyl (
60c
were found
to insert into the primary, secondary, and tertiary C
H bonds of 2,4-dimethylpen-
tane in the ratios 1:2.3:6.0. The insertion of
1
61b
H bonds of
cis
-
and
trans
-1,2-dimethylcyclohexane was completely stereospecific, even under
conditions, which should favor intersystem crossing. Thus, it was unambiguously
shown that insertion is a concerted singlet nitrene reaction and that the triplet nitrene
3
into the tertiary C
H bonds of saturated hydrocarbons.
136b
61b
does not insert into the C
60d
) was photolyzed in methanol, reaction mixture
turned dark.
133
N
-methoxybenzenesulfonamide
When benzenesulfonyl azide (
64d
64d
(15%) and the isomer of
with a structure
(23%) were identified as the products. The latter product was
proposed to be formed by a Curtius-type rearrangement of azide
60d
, followed by
addition of methanol to the intermediate sulfurylaniline (
65d
66d
, Scheme 12.30).
However, the rearrangement of nitrene
1
61d
has not been excluded.
133
to
66d
Photolysis of tosyl azide
60a
in cyclohexane yielded
N
-cyclohexyltosylamide
) with quantum yield 0.018.
142
(
62a
) with quantum yield 0.45 and tosylamide (
63a
The quantum yield for depletion of
was measured to be 0.51. The quantum yields
were the same in air- and nitrogen-saturated solutions.
142
Thermolysis of
60a
60a
in
).
132b
On
cyclohexane gave similar product mixture (
62a
in 58% yield and 5% of
63a
the contrary, photolysis of
60a
in 2-propanol gave mainly
63a
with a quantum yield
0.56 (Scheme 12.31).
142
O
O
O
h
v or
Δ
H
3
C
S
N
3
H
3
C
S
NHC
6
H
11
+
H
3
C
S
NH
2
-N
2
O
O
O
62a
63a
60a
SCHEME 12.31.
Photolysis
142
and thermolysis
132b
of tosyl azide (
60a
).
