- Email: [email protected]
Cycloaddition reaction of tropone with 1,1-dimethyl-2,5-diphenyl-1-silacyclopentadiene
TetnxhedronLetter6 IVo.17, pp 1565 - 1588, 1974.
CYCLOADDITION WITH
REACTION
1,l -DIMETHYL-2,5-DIPHENYL-1
Yutaka
Fujise,
Yasua
Department
Per-n
Hideki
Chemistry,
Sendai
TROPONE
-SILACYCLOPENTADIENE
Chonan,
of
OF
Preee. Printed in &eat Britain.
Sakurai
Tohoku
980,
and ShS
lt6*
University
Japan
(Receivedin J8pBD 5 WIroh 1974; receivedin UK for publication18 Maroh 1974)
Tropone
(I) has been known
to react
C4+21 and Cg+41 (1) cycloadditions, generally
proceed
selectivity
depends
controled group
with
high
largely
I with
respectively,
stereoselectivity,
furane
(5),
dimethylsilylene
C4+21
cycloaddition
acetylenes
In order
to find
II was carried Tropone
under of
II.
m. p.
out
the reaction
atmosphere
preparative
183-183.5’(52%),
imposable
mass spectra
(3),
or 2s
addend
cyclopentadienes
group
the (2c,
course
and olefines
controling
(II) both
(7) and Cztil
these selectivities,
(2).
The
and regioselectivities.
The
C6+43 reaction
3).
being
Modification
termini
(4),
modified
and known
addition
with
peri-
kinetically
by the reactions
(Id)
is another
reactions
of the methylene
as was indicated
spiroC2,4lhepta_4,6_diene
connecting
in C6+41 and
of
3,4-dimethyl-land isobenzo-
butadiene to undergo
with thermal
2,3_dimethylbutadiene
the cycloaddition
reaction
of
a
(8).
I with
the
(9).
(I) was heated
nitrogen The
the factors act
employed,
-silacyclopentadiene
and electropositive with
peri-
4s
1,2,3,4-tetrachloro-5,5-ethylenedioxycyclopentadiene
bulky
silole
to alter
1, I-Dimethyl-2,5-diphenyl-1
(6).
poor
6s,
with
thermodynamically
2,5-dimethyl-3,4-diphenylcyclopentadienone
thio-1 -phenylphosphole
with
conditions
controled
also appears
when heated
but
on the reaction
and the C4+21 reaction
of cyclopentadiene
as an electron-defficient
with
I,1 -dimethyl-2,5_diphenyl-l-silacyclopentadiene
in sealed
TLC
(silica
and the Cm/e 368
tube gel)
impure (M+),
to give resulted minor
a mixture in the
adduct
m/e 262
of two
isolation (IV,
of II
(18%),
amorphous,
19%)
base peak (II+)1
1585
products
of
III
(II) in addition the major (10).
and IV
at 138’
to the recovery adduct
The almost
indicate
for 15 hrs
both
(Ill), super-
to be the
1586
No. 17
,&$hh~~x
,;Gh
jj-!
Me III
1:
1
adducts
I
of
Ultraviolet
and II.
(17230),
255 (15480),
(12970),
284 sh (3000),
284 sh (4060), 292 sh (2100)
1656,
CvKB’ pattern
of these
Of correct
1640,
1250,
compounds
the four structures
possible were
292 sh (2370) f or
IV1
protons,
allows
(shown by the
irradiation
IV
1250,
similar
having
Of
PMR
of
‘7
‘8
‘9
4.34
6.84
4.09
3.53
7.01
5.52
4.21
6.95
3.75
3.65
br.t
d
dd
br.d
Jl,9
Jl,lO
‘1,ll
proton
allylic
ii)
Parameters
-
In both
III
and IV
‘5,6
1,8-
of
the presence
for
IV].
of a
Overall
in
III,
Bll
812
-
6.23
6.43
‘7,8
H7 H,
PMR
‘7,9
adducts),
in the PMR with
spectral
the other
(br.t)
couples
signal
(ddd in
the
vinylic
with Ill
H6
and br.t
in CDCI,) Me
Ph
ex
Me
en
7.15-7.35
-0.42
0.40
%15-7.40
-0.45
0.41
ddd 6.05
ddd
(C&+c2sl
no coupling
(100 MHz
7.15-7.40*6.62
‘6,7
group
observation
?o
ddd
‘1,12
cm-’
compounds,
ddd
5.59
and to that
system as shown by IR spectra
778
with
proton
ddd
dd
255
suggesting
carbonyl
the following
vinylic
signal).
sh
each other.
from
the other
‘6
br. t
1640,
the u,8-unsaturated
85
dd
1664,
with
is the only
of the former
d
(a),
229
229 sh (14890),
to each other
vKBr
?
ddd
similar
for
III,
220 sh (19270),
220 sh (16720),
carbonyl
of H6.
I.
AzrH
an a,8-unsaturated
is also very
identification
III,
CAmax MeoH
contain
H5 which
TABLE
III
cm-’
structures
of
for
compounds
are also quite
deduced for both adducts
i) Irradiation
analysis:
763
of these
C4,3,01-nona-3,7-diene
Both adducts
chromophore.
A
properties
diphenyl-3,4,9,9-tetramethyl-9-silabicyclo stylene
ex
IV
ddd
‘7,11
‘7,12
‘8,9
‘9,lO
‘11,12
III
1.9
-
7.6
1.2
3.0
1.6
8.5
0.7
1.0
7.6
11.0
-
7.6
IV
0.7
6.5
7.5
1.0
3.2
1.1
-
2.1
1.2
7.8
-
11.6
8.5
* Overlaps
with
phenyl signals.
No. 17
1587
TABLE
II.
C4+21 Cycloadditions
Thermal
of Tropone [4+21
X
conditions
.Ph
\
/p*s \
with
Cyclopentadienes
addition references
regioselectivity
peri-
stereo-
selectivity
selectivity
A4
:
A3*
1009
4-6 days
C4+21
endo
1
:
0.6
5
1 loo,
6 days
C4+23
endo
1
:
0.2
4
138’,
15 hrs
C4+21
endo
1
:
0.37
,M=
present
“he
study
:CH*
1270,
>c=o
100°
36 hrs
en&/
C6+41 C4+21
major
exo
:
83
also cf. le
sole
endo
16141
1C
minor
13
prod.
3
C8+21 C4+21 *4 A
in
IV)
appears
in the
to the pammagnetic nuclear
Overhauser
group verifies
field
than
anisotropy effect
signals.
of
iv)
Peri-, TABLE
II,
Although
(br. t in
(8%
coupling
moiety
III
3
refer
in
III
and 3%
in both
in
of the methyl
constants
(J6
adducts
to the following
and br.d
group on the adjacent
in the vicinity
Small
I
in
carbon IV)
iii)
atom.
The
PMR
III
The
attributed
detection
of the
of the endo methyl
group and allows in
structures.
the phenomenon
on irradiation
7) of H6
(11).
IV),
partial
the unequivocal
and IV reveal
parameters
assign-
the endo config-
determined
are I isted
I. stereo-
with
and regioselectivities
those
tropone
previously
tends to offord
completely
absent
in the present
(5).
possible
and probably
One
signal
H,
of the silacyclopentene
in the TABLE
H7 signal
of phenyl
at H,
the presence
ment of methyl uration
low
and A
observed
found
in the reaction
C4+21 adducts reaction
in the present
at higher
of
reaction
I with
the various
temperature
(lc,
as in the cases of spiroC4,21
main factor
for
this
perispecificity
have common features,
is,
6),
as shown
cyclopentadiene the
heptadiene
C6fl
adduct
in
derivatives. was
(4) and the phosphole
as was pointed
out by Tanida
for
ITO. 17
15ee
spiroC4,21 (shown
heptadiene
a severe
in A) of the symmetrically
adducts
predominating
electronic result
(4),
properties
of the
various
calculation
n-n
hindrance
allowed
C6+41
A3 isomers (TABLE
of X.
substituents
to the
over
steric
Both stereo-
of stabilization
studied
II),
It is remarkable
was kept
in all
and regioselectivity energy
so far on cisoid
(2~)
in the
that
observed reaction
have
too small
in these
I
of
transition
regardless
reactions
A4
of the
follow
the
and cyclopentodiene,
effect
state
regioselectivity,
cases examined,
for the
butadiene
bridge
to upset the
suggesting
stabilization
due
interaction.
To whom all
1)
X ond carbon
reaction.
References ’
between
the
An underline
correspondences
is used here
should
to indicate
and Footnotes
be addressed. the mode of addition
of the subject
compound
(tropone
in this
ientence) .
2) z) R.C.
Cookson,
Y.
T.
Okuda
and Y.
Sakan and Y.
Fujise,
Tetrahedron
Fujise,
:1969).
B.V.
e) D. M.
<.N.
Houk
and
Bradby R.B.
-I.
Tanida,
Y.
Kashman
and 0.
-I.
Takeshita,
Y.
-I.
Gilman,
g,
5584
Barton, Ann;
Yano
S.G.
A. J. 4653
and M.
and W.H. Hota
Clardy, A.
Clardy
t.
Org.
Chem.,
9)
If the reaction had .afforded limethyl sililene generator.
J.
J.
C6+43
Org.
Laporterie, and T. J.
Am. 2,
Hatsui, J.
Chem. 1626
2,
191
J.
1351
MS thesis, (1972).
4145
195
Sot.,
Tohoku
Its, K.
University,
(1970). 2,
946
Lett.,
Chem.
335
(1972).
Sot.,
(1973).
86,
1596
(1964).
&,
0
89
Idem, (1%‘85,
B.Resibois Chem. 94,
It&,
(1973).
Dubac,=P.
Barton,
b) S.
c) S.
I,
Chq J.
15 (1966). (1966).
Sakan,
Jopan,
Chem. Am.
K.
Comm.,
39,
Perkin
Sot.
29,
Willis,
d)
Sot.
Sot.,
Chem.
Chem.
Japan,
(1970).
Chem.
Atwell,
(1970).
Sot.
Chem.
Bull.
and C.J.
ond J. J.
Am.
and T.
Nelson
8)
10)
Mori
N.K.
McIntosh,
J.
Tetrahedron,
Cottis
199
2673
Fray,
J.
Morrison,
Chem.
Letters,
Ueyama,
A.
and A.
Bull.
and G. I.
Awerbouch,
Tl971).
J.
Hudec
5, -.
and C.L.
Maruca,
J. Inoue,
Woodward,
Wada,
(1964).
Chim.,
.e :tters, Nitiak
T.
Drake,
6229
Mazerolles Comm., (19 %
and M.
690
(1972).
ibid., TX
and J.C.
Lesbre, T.J.
Brunet,
Tetrahedron -Barton,
J.L.
.
(1971).
adduct,
it was also our intention
to investigate
its possibility
as a
Because of the instability of IV, further IV was obtained only as a mixture with III (III: IV=5:6). The spectral data for IV described in this paper were obtained by subpurification was abandoned. The yields are corrected accordingly. tracting obsorptions due to III from those of the mixture.
11) For coupling Letters, 775
constant (1969).
in the similar
situation,
see 5.
Ita,
K.. Sakan
and Y.
Fujise,
Tetrahedron
CYCLOADDITION WITH
REACTION
1,l -DIMETHYL-2,5-DIPHENYL-1
Yutaka
Fujise,
Yasua
Department
Per-n
Hideki
Chemistry,
Sendai
TROPONE
-SILACYCLOPENTADIENE
Chonan,
of
OF
Preee. Printed in &eat Britain.
Sakurai
Tohoku
980,
and ShS
lt6*
University
Japan
(Receivedin J8pBD 5 WIroh 1974; receivedin UK for publication18 Maroh 1974)
Tropone
(I) has been known
to react
C4+21 and Cg+41 (1) cycloadditions, generally
proceed
selectivity
depends
controled group
with
high
largely
I with
respectively,
stereoselectivity,
furane
(5),
dimethylsilylene
C4+21
cycloaddition
acetylenes
In order
to find
II was carried Tropone
under of
II.
m. p.
out
the reaction
atmosphere
preparative
183-183.5’(52%),
imposable
mass spectra
(3),
or 2s
addend
cyclopentadienes
group
the (2c,
course
and olefines
controling
(II) both
(7) and Cztil
these selectivities,
(2).
The
and regioselectivities.
The
C6+43 reaction
3).
being
Modification
termini
(4),
modified
and known
addition
with
peri-
kinetically
by the reactions
(Id)
is another
reactions
of the methylene
as was indicated
spiroC2,4lhepta_4,6_diene
connecting
in C6+41 and
of
3,4-dimethyl-land isobenzo-
butadiene to undergo
with thermal
2,3_dimethylbutadiene
the cycloaddition
reaction
of
a
(8).
I with
the
(9).
(I) was heated
nitrogen The
the factors act
employed,
-silacyclopentadiene
and electropositive with
peri-
4s
1,2,3,4-tetrachloro-5,5-ethylenedioxycyclopentadiene
bulky
silole
to alter
1, I-Dimethyl-2,5-diphenyl-1
(6).
poor
6s,
with
thermodynamically
2,5-dimethyl-3,4-diphenylcyclopentadienone
thio-1 -phenylphosphole
with
conditions
controled
also appears
when heated
but
on the reaction
and the C4+21 reaction
of cyclopentadiene
as an electron-defficient
with
I,1 -dimethyl-2,5_diphenyl-l-silacyclopentadiene
in sealed
TLC
(silica
and the Cm/e 368
tube gel)
impure (M+),
to give resulted minor
a mixture in the
adduct
m/e 262
of two
isolation (IV,
of II
(18%),
amorphous,
19%)
base peak (II+)1
1585
products
of
III
(II) in addition the major (10).
and IV
at 138’
to the recovery adduct
The almost
indicate
for 15 hrs
both
(Ill), super-
to be the
1586
No. 17
,&$hh~~x
,;Gh
jj-!
Me III
1:
1
adducts
I
of
Ultraviolet
and II.
(17230),
255 (15480),
(12970),
284 sh (3000),
284 sh (4060), 292 sh (2100)
1656,
CvKB’ pattern
of these
Of correct
1640,
1250,
compounds
the four structures
possible were
292 sh (2370) f or
IV1
protons,
allows
(shown by the
irradiation
IV
1250,
similar
having
Of
PMR
of
‘7
‘8
‘9
4.34
6.84
4.09
3.53
7.01
5.52
4.21
6.95
3.75
3.65
br.t
d
dd
br.d
Jl,9
Jl,lO
‘1,ll
proton
allylic
ii)
Parameters
-
In both
III
and IV
‘5,6
1,8-
of
the presence
for
IV].
of a
Overall
in
III,
Bll
812
-
6.23
6.43
‘7,8
H7 H,
PMR
‘7,9
adducts),
in the PMR with
spectral
the other
(br.t)
couples
signal
(ddd in
the
vinylic
with Ill
H6
and br.t
in CDCI,) Me
Ph
ex
Me
en
7.15-7.35
-0.42
0.40
%15-7.40
-0.45
0.41
ddd 6.05
ddd
(C&+c2sl
no coupling
(100 MHz
7.15-7.40*6.62
‘6,7
group
observation
?o
ddd
‘1,12
cm-’
compounds,
ddd
5.59
and to that
system as shown by IR spectra
778
with
proton
ddd
dd
255
suggesting
carbonyl
the following
vinylic
signal).
sh
each other.
from
the other
‘6
br. t
1640,
the u,8-unsaturated
85
dd
1664,
with
is the only
of the former
d
(a),
229
229 sh (14890),
to each other
vKBr
?
ddd
similar
for
III,
220 sh (19270),
220 sh (16720),
carbonyl
of H6.
I.
AzrH
an a,8-unsaturated
is also very
identification
III,
CAmax MeoH
contain
H5 which
TABLE
III
cm-’
structures
of
for
compounds
are also quite
deduced for both adducts
i) Irradiation
analysis:
763
of these
C4,3,01-nona-3,7-diene
Both adducts
chromophore.
A
properties
diphenyl-3,4,9,9-tetramethyl-9-silabicyclo stylene
ex
IV
ddd
‘7,11
‘7,12
‘8,9
‘9,lO
‘11,12
III
1.9
-
7.6
1.2
3.0
1.6
8.5
0.7
1.0
7.6
11.0
-
7.6
IV
0.7
6.5
7.5
1.0
3.2
1.1
-
2.1
1.2
7.8
-
11.6
8.5
* Overlaps
with
phenyl signals.
No. 17
1587
TABLE
II.
C4+21 Cycloadditions
Thermal
of Tropone [4+21
X
conditions
.Ph
\
/p*s \
with
Cyclopentadienes
addition references
regioselectivity
peri-
stereo-
selectivity
selectivity
A4
:
A3*
1009
4-6 days
C4+21
endo
1
:
0.6
5
1 loo,
6 days
C4+23
endo
1
:
0.2
4
138’,
15 hrs
C4+21
endo
1
:
0.37
,M=
present
“he
study
:CH*
1270,
>c=o
100°
36 hrs
en&/
C6+41 C4+21
major
exo
:
83
also cf. le
sole
endo
16141
1C
minor
13
prod.
3
C8+21 C4+21 *4 A
in
IV)
appears
in the
to the pammagnetic nuclear
Overhauser
group verifies
field
than
anisotropy effect
signals.
of
iv)
Peri-, TABLE
II,
Although
(br. t in
(8%
coupling
moiety
III
3
refer
in
III
and 3%
in both
in
of the methyl
constants
(J6
adducts
to the following
and br.d
group on the adjacent
in the vicinity
Small
I
in
carbon IV)
iii)
atom.
The
PMR
III
The
attributed
detection
of the
of the endo methyl
group and allows in
structures.
the phenomenon
on irradiation
7) of H6
(11).
IV),
partial
the unequivocal
and IV reveal
parameters
assign-
the endo config-
determined
are I isted
I. stereo-
with
and regioselectivities
those
tropone
previously
tends to offord
completely
absent
in the present
(5).
possible
and probably
One
signal
H,
of the silacyclopentene
in the TABLE
H7 signal
of phenyl
at H,
the presence
ment of methyl uration
low
and A
observed
found
in the reaction
C4+21 adducts reaction
in the present
at higher
of
reaction
I with
the various
temperature
(lc,
as in the cases of spiroC4,21
main factor
for
this
perispecificity
have common features,
is,
6),
as shown
cyclopentadiene the
heptadiene
C6fl
adduct
in
derivatives. was
(4) and the phosphole
as was pointed
out by Tanida
for
ITO. 17
15ee
spiroC4,21 (shown
heptadiene
a severe
in A) of the symmetrically
adducts
predominating
electronic result
(4),
properties
of the
various
calculation
n-n
hindrance
allowed
C6+41
A3 isomers (TABLE
of X.
substituents
to the
over
steric
Both stereo-
of stabilization
studied
II),
It is remarkable
was kept
in all
and regioselectivity energy
so far on cisoid
(2~)
in the
that
observed reaction
have
too small
in these
I
of
transition
regardless
reactions
A4
of the
follow
the
and cyclopentodiene,
effect
state
regioselectivity,
cases examined,
for the
butadiene
bridge
to upset the
suggesting
stabilization
due
interaction.
To whom all
1)
X ond carbon
reaction.
References ’
between
the
An underline
correspondences
is used here
should
to indicate
and Footnotes
be addressed. the mode of addition
of the subject
compound
(tropone
in this
ientence) .
2) z) R.C.
Cookson,
Y.
T.
Okuda
and Y.
Sakan and Y.
Fujise,
Tetrahedron
Fujise,
:1969).
B.V.
e) D. M.
<.N.
Houk
and
Bradby R.B.
-I.
Tanida,
Y.
Kashman
and 0.
-I.
Takeshita,
Y.
-I.
Gilman,
g,
5584
Barton, Ann;
Yano
S.G.
A. J. 4653
and M.
and W.H. Hota
Clardy, A.
Clardy
t.
Org.
Chem.,
9)
If the reaction had .afforded limethyl sililene generator.
J.
J.
C6+43
Org.
Laporterie, and T. J.
Am. 2,
Hatsui, J.
Chem. 1626
2,
191
J.
1351
MS thesis, (1972).
4145
195
Sot.,
Tohoku
Its, K.
University,
(1970). 2,
946
Lett.,
Chem.
335
(1972).
Sot.,
(1973).
86,
1596
(1964).
&,
0
89
Idem, (1%‘85,
B.Resibois Chem. 94,
It&,
(1973).
Dubac,=P.
Barton,
b) S.
c) S.
I,
Chq J.
15 (1966). (1966).
Sakan,
Jopan,
Chem. Am.
K.
Comm.,
39,
Perkin
Sot.
29,
Willis,
d)
Sot.
Sot.,
Chem.
Chem.
Japan,
(1970).
Chem.
Atwell,
(1970).
Sot.
Chem.
Bull.
and C.J.
ond J. J.
Am.
and T.
Nelson
8)
10)
Mori
N.K.
McIntosh,
J.
Tetrahedron,
Cottis
199
2673
Fray,
J.
Morrison,
Chem.
Letters,
Ueyama,
A.
and A.
Bull.
and G. I.
Awerbouch,
Tl971).
J.
Hudec
5, -.
and C.L.
Maruca,
J. Inoue,
Woodward,
Wada,
(1964).
Chim.,
.e :tters, Nitiak
T.
Drake,
6229
Mazerolles Comm., (19 %
and M.
690
(1972).
ibid., TX
and J.C.
Lesbre, T.J.
Brunet,
Tetrahedron -Barton,
J.L.
.
(1971).
adduct,
it was also our intention
to investigate
its possibility
as a
Because of the instability of IV, further IV was obtained only as a mixture with III (III: IV=5:6). The spectral data for IV described in this paper were obtained by subpurification was abandoned. The yields are corrected accordingly. tracting obsorptions due to III from those of the mixture.
11) For coupling Letters, 775
constant (1969).
in the similar
situation,
see 5.
Ita,
K.. Sakan
and Y.
Fujise,
Tetrahedron