Tetrahedron Letters,Vol.27,No.46,pp Printed in Great Britain
REACTION
5625-5628,1986
OF SILYLENE
ALKYLIDENESILACYCLOPROPANE
Wataru
Ando*
Department
and Haruo
Ibaraki
WITH ALLENES:
AND SILATRIMETHYLENEMETHANE
Saso
of Chemistry,
Sakura-mura,
0040-4039/86 $3.00 + .oO Pergamon Journals Ltd.
University
of Tsukuba
305, Japan
Summary; Reaction of photogenerated dimesitylsilylene with tertbutyldimethylallene and tert-butylallene yielded the corresponding alkylidenesilacyclopropanes. Its photochemical behavior and some reactions with nucleophiles are described.
Because studies
of the unique
properties
of silicon-containing
in recent targets
silicon
However,
silicon
features
the isolation
far as we know.2) reaction
from
high
strain
ring compounds
of silylene
because
of trimethylenemethane
method
with
silicon
appears
toward
to be most
the synthesis
the
specially
analogue
species. reported
formation
suitable,
and some
suited
structural
has not been
of alkylidenesilacyclopropane
allene
results
are
of the unique
of alkylidenesilacyclopropane
Direct
here our preliminary
compounds,
energy,
have been fruitful
chemistry. ') Alkylidenesilacyclopropanes
for such strained
and mechanistic
resulting
three-membered
so
by a
and we present
reactions
of
alkylidenesilacyclopropanes. Irradiation (1 mmol)
with
low pressure preparative were
of cyclohexane excess mercury
GLC(lO%
obtained
was
isolated found
by bulky ofzin
7% yields
to be thermally
isomerization
shift
and 2.
A similar
allene,
in which
photochemically mercury
of 5 or direct
phenomenon product
owing
isolated
gave3in
5625
2 has not
shift
shift
generates
42% yield.
isomerization
These of
to 2
to give z.4' via 5 or
as described 5 at first
in the reaction
2
2. Photolysis
5 in the course
by the rapid
in 27% yield
alkylidenesilacyclopropane.
trisilane,
to the protection
to compound
by the mechanism
by hydrogen
was observed
5 was
lamp
1,3-hydrogen
of silylene
2 and 3
alkylidenesilacyclopropane
of silatrimethylenemethane
to 4 via 2 followed
by
compound
23% of remained
and inert to methanol
of 2 is explained
addition
with
Although
of 2 is also interpreted
direct
separated
products,
1
out with
data. 3, Alkylidenesilacyclopropane
low pressure
to 3. Absence
1,4-hydrogen
Alternatively,
stable
was carried
were
major
respectively,
mixture.
the intermediacy
Photoisomerization
B). Two
it undergoes
with
of 2,2-dimesitylhexamethyltrisilane
for 5.5 hr. The products on Uniport
the reaction
substituents,
the procedure with
from
suggest
solution
of tert-butyldimethylallene
by spectroscopic
cyclohexane
results
lamp SE-30
in 36 and
and characterized been
amount
with
without
above. step
to give 2
tetramethyl-
any isolation
of
5626
1
Mes Mes 'Si' Me
-2
tBuCH=cCMe2
1,3-H-Shift \ /
Mes Mej;iS#iSiMe -Mes2Si: 3 Mes
1,4-H-Shift \
I tBu
Me2C=C
\
J
Me -5
Me
tBu -3
Me
Mes=
Me
Me
Me -6
Irradiation
of cyclohexane
tert-butylallene
72, JE
cyclopropanes studies,5)
together
was purified able
Much
with
30% yields
in benzene in CDC13
reaction
in contrast G.
In view
carbonyl
cleavages.a) quite
analogue,
not bonding
higher
'H-NMR
polarity
the other B
and 8 were
for the formation
with
Si-vinyl
B not
of 2 is not
lies in the -72
reacted
smoothly
found
to double of Si-vinyl
cleavage
with
15% of the adduct
of methanol
step
followed
oxygen
and
by Si-C bond
with
of -10 and -12 is alkylidenecyclopropane and its
the cleavage
This reactivities which
The
for the formation
of a simple
to proceed
bond
attack
the first
respectively.
by X-
Ilb and 12b in quantitatively,
p-chlorobenzaldehyde
is probably
bond.
and 12a was confirmed
studies')
two adducts
nucleophilic
bond
'I1a
of
spectroscopic
yielded
since the systems have
on NMR
2. Whereas
and with -10 in quantitatively, two oxasilacyclopentanes j& and 12a in 40 and
results,
on silicon
The
surprising
hetero bond
to the reaction
oxygen
respectively,
Alkylidenesilacyclopropane
The stereochemistry
p-anisaldehyde
of these
of
to give methoxysilane
and 400 MHz
with
hexane,
amount
of alkylidenesila-
of alkylidenesilacyclopropane
to give
respectively.
ray analysis6)
excess
stage.
for nucleophiles.
methanol
from
with
isomers
tert-butylacetylene
form. The explanation
of the attractiveness
benzaldehyde
of three
7% of unexpected
as stable
at the present
reactivities
of 1 (1 mmol)
and 8, in 31, 22 and 8% yields with
by recrystallization
to isolate
apparent
solution
for 14 hr gave a mixture
of C-C or C-hetero
can be explained
is additionally
caused
by the
by alkylidene
5621
Mes Mes 'Si'
Mes Mes ‘Si' Mes2Si:
tBuCH=C=CH2
+
-
+
&+ tBGf -8
-72 and -7E
tBuCH=CHCH2Si(OMe)Mes2
Mes Mes 'Si'
MeOH -tB@
tBuCZCCH2SiHMes
2
-9
X DHO
Mes~;+2s~X tBu
10
substitution.') migration
Whereas,
reaction
Further
e;X=H X= H *; Q; X= OMe 5: X= OMe c; x= Cl
-72
the facile
seems
studies
Si-C bond
to be suitable
are continued
cleavage
and simultaneous
for the formation
for the photochemistry
n-bond
of 11.
of alkylidenesilacyclo.
propanes.
Acknowledgment; Institute indebted
We are sincerely
for Polymers
grateful
and Textiles
to Shin-etsu
Chemical
Co.,Ltd.
References
(I)
(a) T.J.Barton, Chemistry, (1982), Lett.,
Vo1.2,
~206.
Y.Hamada,
(c) W.Ando,
(a) D.Seyferth,
T.Higuchi, (3)
'H-NMR
Y.Hamada,
S.Murakami,
H.Tobita,
New-York
Tetrahedron
K.Ueno,
ibid.,
J.Am.Chem.Soc.,
S.Murakami,
K.J.Haller,
E.W.Abel,
105,
ibid.,s,7776(1983).
ibid., =,4942(1985).,and
therein.
M.Ishikawa,
S.Matsuzawa,
E,237(1975).
(b) G.T.Burns,
(c) For
Alkylidenedisila-
H.Sugisawa,
F.Yano,
S.Kamitori,
x,7706(1985).
(CDC13) 6 1.08(s,9H),2.06(s,3H),2.19(s,3H),2.38(s,6H),2.70
(s,I~H),~.OI(S,~H). A ring region.
Organometallic
K.Ueno,
A.Sekiguchi,
J.Organometal.Chem.,
ibid.,
of 2
We are
organochlorosilanes.
F.G.A.Stone and
A.Sekiguchi,
T.J.Barton, J.Am.Chem.Soc., E,2006(1983). cyclopropanes;
of
in Research
analysis.
in Comprehensive
H.Tobita,
D.J.De Young, cited
Ueno
structure
and Notes --
silanes"
(e) S.Masamune,
(f) R.West,
for a gift
by G.Wilkinson,
(d) S.Masamune,
6473(1983).
references
eds.
(b) W.Ando,
1982,5323.
1983,4033.
(2)
"Carbocyclic
to Dr. Katsuhiko
for the X-ray
13C-NMR
proton
of 2 (CDC13)
was
obscured
in methyl
or mesityl
6 21.14(q),24.01(q),24.19(q),24.89(q),26.83
(q),32.00(q),34.70(s),41.20(d),128.34(d),128.58(d),~29.40(s),~34.39(s), 138.79(s),139.03(s),141.90(s),144.55(s),145.13(s).
Mass
m/e
390(M+).
5628
(4)
(a) M.Ishikawa,
x,155(1978).
Chem.,
(5)
K.Nakagawa,
M.Ishiguro,
F.Ohi,
(b) M.Ishikawa,
M.Kumada,
K.Nakagawa,
J.Organometal.
M.Kumada,
178 105(1979). ibid * ,_I Two fractions of a mixture
of -72 and 8, and a mixture of -7E and 2, were separated by HPLC. -_ 72; m-p. 116-118°C. 400 MHz 'H-NMR(CDC13)s l.O3(s,9H), 1.52(d,2H,J=2.6Hz),2.24(s,6H),2.46(s,l2H),6,46(t,lH,J=2.6Hz),6.78(s,4H). Stereochemistry
ring
of B
was determined
proton(l.52ppm)
proton(6.46ppm). not effective
caused
Overhauser
irradiation
However, to ring
by the NOE spectrum.
a nuclear
proton.
at tert-butyl
13C-NMR
(CDCl,)&
Irradiation
effect(NOE)
at
of vinyl
proton(l.03ppm)
was
16.43(t),21.15(¶),
23.75(q),29.65(q),35.29(s),128.410,129.22(s),139.30(s),~44.56(s), 148.43(d).
Mass
m/e
362(M+).
2;
'H-NMR
J=3Hz),2.25(s,6H),2.53(s,l2H),6.52(t,lH, (Ccl,)&
(CC14) 6 1.15(s,9H),1.69(d,2H, J=3Hz),6.85(s,4H).
8; 'H-NMR
0.95(s,9H),l.81(br.t,lH),J=3.6Hz),2.24(s,l2H),2.58(s,6H),
6.24(br.d,2H,J=3.6Hz),6.69(s,4H). (6)
The
crystal
c=14.442%,
and
R value
4OOMHz
space
group
Pl with
~=70.30°,8=96.660,y=106.860.
The
b=l3.604fi,
a=8.578i, structure
was
refined
to an
of 0.0895. ORTEP
Figure.
(7)
has triclinic
'H-NMR
drawing
of &
1 la
of
(CDC13)
6
1.07(s,9H),2.07(d,lH,J=l5Hz),2.21(s,3H),
2.23(s,6H),2.24(s,3H),2.43(s,6H),5.45(br.s,lH),6.23(br.s,lH),6.76(s,2H), 6.78(s,2H),7.19-7.26(m,3H),7.38(br.d,2H). proton(l.07ppm) (6.23ppm) thank
caused
and ortho
Mr. Yasushi
a NOE
protons
Nagai
Irradiation
of a benzyl of phenyl
at tert-butyl
proton(5.45ppm),a
group(7.38ppm).
for a help of 40OMHz
'H-NMR
vinyl
The authers
proton wish
the spectroscopic
measurement. (8) (9)
D.Seyferth,
D.P.Duncan,
M.L.Shannon,
In methylenecyclopropane, character
in
calculation.
sp2 ring carbon See;
89,3966(1967). (Received
in Japan
28 June
Organometallics,2,579(1984).
1986)
N.C.Braid,
atom
has the most
M.J.S.Dewar,
anionic
J.Am.Chem.Soc.,
to