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Cosensitization by 9,10-dicyanoanthracene and biphenyl of the electron-transfer photooxygenation of 1,1,2,2-tetraphenylcyclopropane
Tetrahedron Letters,Vol.23,No.52,pp Printed in Great Britain
COSENSITIZATION
BY 9,10-DICYANOANTHRACENE
PHOTOOXYGENATION
A. Paul Schaap,*
AND BIPHENYL
OF THE ELECTRON-TRANSFER
OF 1,1,2,2-TETRAPHENYLCYCLOPROPANEl
Luigi Lopez,
Department
0040-4039/82/525493-04$03.00/O 01982 Pergamon Press Ltd.
5493-5496,1982
Stuart D. Anderson,
and Steven D. Gagnon
of Chemistry, Wayne State University Detroit, Michigan 48202
Electron-transfer photooxygenation of 1,1,2,2-tetraphenylcyclopropane with 9,10Summary: dicyanoanthracene in oxygen-saturated acetonitrile yields 1,1,3,3-tetraphenyl-2-propen-l-01 after reduction of the intermediate hydroperoxide. The rate of reaction is significantly increased by the addition of biphenyl as a cosensitizer.
Electron-transfer acetylenes, presence
and sulfides
are oxidized
of electron-deficient
tion of a cyclopropane light-absorbing, reaction
photooxygenation
has received
upon irradiation
sensitizers.
with the formation
chemically
considerable
unreactive
in oxygen-saturated
We now report of a ring-opened
aromatic
attention
hydrocarbon
polar solvents
the first example hydroperoxide.
Olefins,
recently.'
3
as a cosensitizer
in the
of the photooxygenaThe use of a nonto accelerate
is also described.
Ph2
Photooxygenation
A
Ph2
I.
DCA,
2.
Ph,P
h?, 4 )
of 1, 1,2,2-tetraphenylcyclopropane
PhQPh2 2
HO
(L) was carried
out in dry acetonitri le
-3 with 6 x 10 M _1 and 6 x 10-4 M 9,10-dicyanoanthracene(DCA). The solution was irradiated 1O'C under oxygen with a 450-W medium-pressure reaction
the
was monitored
by hplc and judged
mercury
complete
in 19 h.
with 1 equivalent
of Ph3P to reduce
hexane
gave 1,143,3-tetraphenyl-2-propen-l-01
as elutant
also identified
as a reaction
the hydroperoxide
product.
7
5493
lamp using a CuS04-filter Treatment
and chromatography
at
solution.4
of the reaction
The
mixture
over silica gel with
(Jj5 in 60% yield.
Benzophenone
(4) was
5494
Arnold8
and Roth' have
shown that photo-induced
tuted cyclopropanes
result
plausible
for the conversion
mechanism
in the formation
transfer
fluorescence
quenching
Reaction
of -1' with superoxide 10
hydrogen
to yield -2.
cleavage
of hydroperoxide
Rose Bengal,
indicating
We have recently oxirane
to produce
biphenyl
experiments Further,
that singlet
observed
of 6 x 10
-3
hJ
DCA
-
I
- Ph,APh, I’
+
‘DC;
-
BP’
BP’
+
-
It
+
I
02
O2
ph,’
t -1 .
abstracts
upon irradiation solution
photooxygenation enhanced
q
Ph, -00
for 38
containing
DCA-
+
+
DCh
BP
+
DCA
Ph2qPh2 HO0 2
of
of -1 can be in 1.5 h.
the reaction.
during
+
of tetraphenyl-
by the addition
is complete
Dd
‘Dd
I
I? + 0;
consumed
+
DCA-
cation
in the reaction.
M BP, the reaction
of DCA.
BP
A
electron-
of radical
Simi .arly, we have found that the oxidation
occurs
Ph,
involves
acetonitrile
can be dramatically
that the BP is not appreciably
n
cleavage.
subsequently
1 was not oxidized
is not involved
sis by hplc indicated
Ph,
which
of aryl-substi-
have shown that one source of 5 is the photooxidative
ozonide
12
In the presence
in the absence
biradical
that the rate of DCA-sensitized
the corresponding
by BP.
2, therefore,
DCA by 1 with generation
cyclopropane
oxygen
reactions
cations with C-C bond
sodium lamp in an oxygen-saturated
(BP) as a cosensitizer.
accelerated
excited
forms an intermediate
11
h with a 400-W high-pressure
of radical
of 1 to hydroperoxide
of singlet
Control -2.
electron-transfer
13
Analy-
No reaction
5495
We have previously
reported
(p-methoxyphenyl)-1,4-dioxene
that the rate of DCA-sensitized
= 0.73 V vs. SCE, in MeCN) was increased
(EG
2,3-bis(E-methylphenyl)-1,4-dioxene recently
been described
of trans-stilbene. controlled electron
In present
d's_1)
case the cosensitizer
BP (E;
than the substrate 1 is a less effective
result would
seem to suggest
Although deficient
1 is subsequently the mechanism
sensitizers
tion of a variety
and aromatic
We thank Dr. G. Prasad
Support
18
enhance
olefin
Research
may prove
is continuing
BP (kq = 3.1 x 10'
Nevertheless, of 1.
This
of cage-
potential
of 1.
step by BP'.
cosensitization
in our laboratory
Office
oxidation
for the formation
to be generally
from
oxidizedolefin.
has a higher
electron-transfer
from the U.S. Army Research with
results
the rate of oxidation
is not fully delineated,
have
1 DCA* at diffusion-
As a result,
the efficiency
of
in the presence
(k = 1 1 x 101' M-ls-1)-l' 4 -
in an exothermic
hydrocarbons
for assistance
quench
+ than for _. 1 in spite of the lower oxidation
of catalysis
of substrates.
Acknowledgements.
the olefins
= 1.85 V vs. SCE, in MeCN)
of 'DCA* than 1
oxidized
results
cation of the more difficultly
that in lDCA* quenching greater
in the presence
Similar
of the more easily oxidized
of BP is able to greatly
+ BP' is significantly
2k
of 2,3-bis
of tetraphenylethylene
(Ez" = 1.38 V vs. SCE, in MeCN).
quencher
concentration
Cyclopropane
reactivity
of that olefin with the radical
an equimolar
escaped
= 0.84 V vs. SCE, in MeCN).
In both of these reactions,
rates and the enhanced
exchange
potential
(ET
by Foote for the photooxygenation
14,15
photooxygenation
useful
by electronfor the oxida-
on this problem.
is gratefully
acknowledged.
several experiments.
References
and Notes
(1)
Presented in part at the IX IUPAC Symposium Abstr. No. ST 15.
(2)
(a) D. H. R. Barton, G. Leclerc, P. D. Magnus, and I. D. Menzies, .I. Chem. Sot., Chem. Commun., 447 (1972); (b) J. Eriksen, C. S. Foote, and T. L. Parker, J. Am. Chem. Sot., 2, 6455 (1977); (c) R. K. Haynes, Aust. J. Chem., 2, 121 (1978); (d) K. A. Brown-Wensley, S. L. Mattes, and S. Farid, J. Am. Chem. Sot., 100, 4162 (1978); (e) I. Saito, K. Tamoto, and T. Matsuura, Tetrahedron Lett., 2889 (1979); (f) N. Berenjian, P. deMayo, F. H. Phoenix, and A. C. Weedon, ibid., 4179 (1979); (g) W. Ando, T. Nagashima, K. Saito, and S. Kohmoto, J. Chem. Sot., Chem. Commun., 154 (1979); (h) S. L. Mattes and S. Farid, ibid., 126 (1980); (i) J. Eriksen and C. S. Foote, J. Am. Chem. Sot., 102, 6083 (1980); (j) L. T. Spada and C. S. Foote, _., ibid E, 391 (1980); (k) A. P. Schaap, K. A. Zaklika, B. Kaskar, and L. W.-M. Fung, ibid., 102, 389 (1980); (1) S. L. Mattes and S. Farid, ibid., 104, 1454 (1982).
on Photochemistry,
Pau, France,
July 26, 1982,
5496
(3)
Dr. K. Mizuno, Osaka Prefecture University, Japan, has isolated 1,2-dioxolanes from the DCA-sensitized photooxygenation of methoxyphenyl-substituted cyclopropanes. We thank Dr. Mizuno for communicating these results to us.
(4)
The l-cm path-length filter solution was prepared from 27 g of CuS04.5 H20, 30 g of NaN02 and 50 mL of cont. NH40H diluted with water to 1000 mL.
(5)
The mp (138-139°C) and spectral properties those of an authentic sample of 2. 6
(6)
A. R. Ubbelohde
(7)
Preliminary evidence has been obtained tetraphenyl-1,2-dioxolane.
and J. A. Burgess,
(8)
D. R. Arnold
(9)
H. D. Roth and M. L. M. Schilling,
of the isolated
alcohol?
were
identical
to
J. Chem. Sot. (B), 1106 (1970).
and R. W. R. Humphreys,
for the formation
of minor
J. Am. Chem. Sot., 101,
J. Am. Chem. Stc., 102,
amounts
of 3,3,5,5-
2743 (1979).
1958 (1980).
(10)
Alternatively, groun_d-stat5 oxygen could add to 1' with subsequent reduction of the peroxy ~~~iElf~:~~~nb~l~zl, DCA., 1 or BP. Arnold8 has shown that 1,1,3,3_tetraphenylpropene dicyanonaphthalene-sensitized irradiation of 1 in deoxygenated acetonitrile. However, we do not observe the formation of 5 under our-reaction conditions. Control experiments with authentic 2 have shown that th& olefin is significantly less reactive than -1.
(11)
Photooxygenation of 2 in MeCN with DCA and BP gives a solution which produces chemiluminescence upon heating with concomitant formation of 4. These results are evidence for an intermediate 1,2-dioxetane. The other product of the decomposition is presently being identified.
(12)
A. P. Schaap,
(13)
Using a C-18 reverse water.
(14)
D. S. Steichen
(15)
Farid16 and Pac17 have observed enhanced rates for other types of electron-transfer sensitized reactions through the use of cosensitizers.
(16)
(a) S. Farid, S. E. Hartman, and T. R. Evan in "The Exciplex"; M. Gordon and W. R. Ware, Eds.; Academic Press; New York, 1975, p. 327; (b) S. L. Mattes and S. Farid, Act. Chem. &., 15, 80 (1982); (c) K. A. Brown-Wensley, S. L. Mattes, and S. Farid, J. Am. Chem. SOC., 100, 4162 (1978).
L. Lopez,
and S. D. Gagnon,
J. Am. Chem. Sot., submitted.
phase column and elution with a gradient
and C. S. Foote, J. Am. Chem. Sot., 103,
J. Am. Chem. Sot., 103,
(18) (19)
The dependence of quenching rates on the free energy change involved in the electrontransfer process has been described by Rehm and Weller.20 Eriksen and FooteZ1 have considered the specific case of DCA quenching.
(20)
D. Rehm and A. Weller,
(21)
J. Eriksen
USA
Isr. J. Chem., 8, 259 (1970).
31 August
1982).
(1981).
3994 (1969).
and C. S. Foote, J. Phys. Chem., 82, 2659 (1978). in
4499
photo-
T. Majima,
J. Am. Chem. Sot., 91,
in
1855 (1981).
T. Osa A. Yildiz,
and T. Kuwana,
and H. Sakurai,
acetonitrile
(17)
(-Received
C. Pat, A. Nakasone,
of 30-100%
COSENSITIZATION
BY 9,10-DICYANOANTHRACENE
PHOTOOXYGENATION
A. Paul Schaap,*
AND BIPHENYL
OF THE ELECTRON-TRANSFER
OF 1,1,2,2-TETRAPHENYLCYCLOPROPANEl
Luigi Lopez,
Department
0040-4039/82/525493-04$03.00/O 01982 Pergamon Press Ltd.
5493-5496,1982
Stuart D. Anderson,
and Steven D. Gagnon
of Chemistry, Wayne State University Detroit, Michigan 48202
Electron-transfer photooxygenation of 1,1,2,2-tetraphenylcyclopropane with 9,10Summary: dicyanoanthracene in oxygen-saturated acetonitrile yields 1,1,3,3-tetraphenyl-2-propen-l-01 after reduction of the intermediate hydroperoxide. The rate of reaction is significantly increased by the addition of biphenyl as a cosensitizer.
Electron-transfer acetylenes, presence
and sulfides
are oxidized
of electron-deficient
tion of a cyclopropane light-absorbing, reaction
photooxygenation
has received
upon irradiation
sensitizers.
with the formation
chemically
considerable
unreactive
in oxygen-saturated
We now report of a ring-opened
aromatic
attention
hydrocarbon
polar solvents
the first example hydroperoxide.
Olefins,
recently.'
3
as a cosensitizer
in the
of the photooxygenaThe use of a nonto accelerate
is also described.
Ph2
Photooxygenation
A
Ph2
I.
DCA,
2.
Ph,P
h?, 4 )
of 1, 1,2,2-tetraphenylcyclopropane
PhQPh2 2
HO
(L) was carried
out in dry acetonitri le
-3 with 6 x 10 M _1 and 6 x 10-4 M 9,10-dicyanoanthracene(DCA). The solution was irradiated 1O'C under oxygen with a 450-W medium-pressure reaction
the
was monitored
by hplc and judged
mercury
complete
in 19 h.
with 1 equivalent
of Ph3P to reduce
hexane
gave 1,143,3-tetraphenyl-2-propen-l-01
as elutant
also identified
as a reaction
the hydroperoxide
product.
7
5493
lamp using a CuS04-filter Treatment
and chromatography
at
solution.4
of the reaction
The
mixture
over silica gel with
(Jj5 in 60% yield.
Benzophenone
(4) was
5494
Arnold8
and Roth' have
shown that photo-induced
tuted cyclopropanes
result
plausible
for the conversion
mechanism
in the formation
transfer
fluorescence
quenching
Reaction
of -1' with superoxide 10
hydrogen
to yield -2.
cleavage
of hydroperoxide
Rose Bengal,
indicating
We have recently oxirane
to produce
biphenyl
experiments Further,
that singlet
observed
of 6 x 10
-3
hJ
DCA
-
I
- Ph,APh, I’
+
‘DC;
-
BP’
BP’
+
-
It
+
I
02
O2
ph,’
t -1 .
abstracts
upon irradiation solution
photooxygenation enhanced
q
Ph, -00
for 38
containing
DCA-
+
+
DCh
BP
+
DCA
Ph2qPh2 HO0 2
of
of -1 can be in 1.5 h.
the reaction.
during
+
of tetraphenyl-
by the addition
is complete
Dd
‘Dd
I
I? + 0;
consumed
+
DCA-
cation
in the reaction.
M BP, the reaction
of DCA.
BP
A
electron-
of radical
Simi .arly, we have found that the oxidation
occurs
Ph,
involves
acetonitrile
can be dramatically
that the BP is not appreciably
n
cleavage.
subsequently
1 was not oxidized
is not involved
sis by hplc indicated
Ph,
which
of aryl-substi-
have shown that one source of 5 is the photooxidative
ozonide
12
In the presence
in the absence
biradical
that the rate of DCA-sensitized
the corresponding
by BP.
2, therefore,
DCA by 1 with generation
cyclopropane
oxygen
reactions
cations with C-C bond
sodium lamp in an oxygen-saturated
(BP) as a cosensitizer.
accelerated
excited
forms an intermediate
11
h with a 400-W high-pressure
of radical
of 1 to hydroperoxide
of singlet
Control -2.
electron-transfer
13
Analy-
No reaction
5495
We have previously
reported
(p-methoxyphenyl)-1,4-dioxene
that the rate of DCA-sensitized
= 0.73 V vs. SCE, in MeCN) was increased
(EG
2,3-bis(E-methylphenyl)-1,4-dioxene recently
been described
of trans-stilbene. controlled electron
In present
d's_1)
case the cosensitizer
BP (E;
than the substrate 1 is a less effective
result would
seem to suggest
Although deficient
1 is subsequently the mechanism
sensitizers
tion of a variety
and aromatic
We thank Dr. G. Prasad
Support
18
enhance
olefin
Research
may prove
is continuing
BP (kq = 3.1 x 10'
Nevertheless, of 1.
This
of cage-
potential
of 1.
step by BP'.
cosensitization
in our laboratory
Office
oxidation
for the formation
to be generally
from
oxidizedolefin.
has a higher
electron-transfer
from the U.S. Army Research with
results
the rate of oxidation
is not fully delineated,
have
1 DCA* at diffusion-
As a result,
the efficiency
of
in the presence
(k = 1 1 x 101' M-ls-1)-l' 4 -
in an exothermic
hydrocarbons
for assistance
quench
+ than for _. 1 in spite of the lower oxidation
of catalysis
of substrates.
Acknowledgements.
the olefins
= 1.85 V vs. SCE, in MeCN)
of 'DCA* than 1
oxidized
results
cation of the more difficultly
that in lDCA* quenching greater
in the presence
Similar
of the more easily oxidized
of BP is able to greatly
+ BP' is significantly
2k
of 2,3-bis
of tetraphenylethylene
(Ez" = 1.38 V vs. SCE, in MeCN).
quencher
concentration
Cyclopropane
reactivity
of that olefin with the radical
an equimolar
escaped
= 0.84 V vs. SCE, in MeCN).
In both of these reactions,
rates and the enhanced
exchange
potential
(ET
by Foote for the photooxygenation
14,15
photooxygenation
useful
by electronfor the oxida-
on this problem.
is gratefully
acknowledged.
several experiments.
References
and Notes
(1)
Presented in part at the IX IUPAC Symposium Abstr. No. ST 15.
(2)
(a) D. H. R. Barton, G. Leclerc, P. D. Magnus, and I. D. Menzies, .I. Chem. Sot., Chem. Commun., 447 (1972); (b) J. Eriksen, C. S. Foote, and T. L. Parker, J. Am. Chem. Sot., 2, 6455 (1977); (c) R. K. Haynes, Aust. J. Chem., 2, 121 (1978); (d) K. A. Brown-Wensley, S. L. Mattes, and S. Farid, J. Am. Chem. Sot., 100, 4162 (1978); (e) I. Saito, K. Tamoto, and T. Matsuura, Tetrahedron Lett., 2889 (1979); (f) N. Berenjian, P. deMayo, F. H. Phoenix, and A. C. Weedon, ibid., 4179 (1979); (g) W. Ando, T. Nagashima, K. Saito, and S. Kohmoto, J. Chem. Sot., Chem. Commun., 154 (1979); (h) S. L. Mattes and S. Farid, ibid., 126 (1980); (i) J. Eriksen and C. S. Foote, J. Am. Chem. Sot., 102, 6083 (1980); (j) L. T. Spada and C. S. Foote, _., ibid E, 391 (1980); (k) A. P. Schaap, K. A. Zaklika, B. Kaskar, and L. W.-M. Fung, ibid., 102, 389 (1980); (1) S. L. Mattes and S. Farid, ibid., 104, 1454 (1982).
on Photochemistry,
Pau, France,
July 26, 1982,
5496
(3)
Dr. K. Mizuno, Osaka Prefecture University, Japan, has isolated 1,2-dioxolanes from the DCA-sensitized photooxygenation of methoxyphenyl-substituted cyclopropanes. We thank Dr. Mizuno for communicating these results to us.
(4)
The l-cm path-length filter solution was prepared from 27 g of CuS04.5 H20, 30 g of NaN02 and 50 mL of cont. NH40H diluted with water to 1000 mL.
(5)
The mp (138-139°C) and spectral properties those of an authentic sample of 2. 6
(6)
A. R. Ubbelohde
(7)
Preliminary evidence has been obtained tetraphenyl-1,2-dioxolane.
and J. A. Burgess,
(8)
D. R. Arnold
(9)
H. D. Roth and M. L. M. Schilling,
of the isolated
alcohol?
were
identical
to
J. Chem. Sot. (B), 1106 (1970).
and R. W. R. Humphreys,
for the formation
of minor
J. Am. Chem. Sot., 101,
J. Am. Chem. Stc., 102,
amounts
of 3,3,5,5-
2743 (1979).
1958 (1980).
(10)
Alternatively, groun_d-stat5 oxygen could add to 1' with subsequent reduction of the peroxy ~~~iElf~:~~~nb~l~zl, DCA., 1 or BP. Arnold8 has shown that 1,1,3,3_tetraphenylpropene dicyanonaphthalene-sensitized irradiation of 1 in deoxygenated acetonitrile. However, we do not observe the formation of 5 under our-reaction conditions. Control experiments with authentic 2 have shown that th& olefin is significantly less reactive than -1.
(11)
Photooxygenation of 2 in MeCN with DCA and BP gives a solution which produces chemiluminescence upon heating with concomitant formation of 4. These results are evidence for an intermediate 1,2-dioxetane. The other product of the decomposition is presently being identified.
(12)
A. P. Schaap,
(13)
Using a C-18 reverse water.
(14)
D. S. Steichen
(15)
Farid16 and Pac17 have observed enhanced rates for other types of electron-transfer sensitized reactions through the use of cosensitizers.
(16)
(a) S. Farid, S. E. Hartman, and T. R. Evan in "The Exciplex"; M. Gordon and W. R. Ware, Eds.; Academic Press; New York, 1975, p. 327; (b) S. L. Mattes and S. Farid, Act. Chem. &., 15, 80 (1982); (c) K. A. Brown-Wensley, S. L. Mattes, and S. Farid, J. Am. Chem. SOC., 100, 4162 (1978).
L. Lopez,
and S. D. Gagnon,
J. Am. Chem. Sot., submitted.
phase column and elution with a gradient
and C. S. Foote, J. Am. Chem. Sot., 103,
J. Am. Chem. Sot., 103,
(18) (19)
The dependence of quenching rates on the free energy change involved in the electrontransfer process has been described by Rehm and Weller.20 Eriksen and FooteZ1 have considered the specific case of DCA quenching.
(20)
D. Rehm and A. Weller,
(21)
J. Eriksen
USA
Isr. J. Chem., 8, 259 (1970).
31 August
1982).
(1981).
3994 (1969).
and C. S. Foote, J. Phys. Chem., 82, 2659 (1978). in
4499
photo-
T. Majima,
J. Am. Chem. Sot., 91,
in
1855 (1981).
T. Osa A. Yildiz,
and T. Kuwana,
and H. Sakurai,
acetonitrile
(17)
(-Received
C. Pat, A. Nakasone,
of 30-100%