Reaction of silylene with allenes: Alkylidenesilacyclopropane and silatrimethylenemethane

Reaction of silylene with allenes: Alkylidenesilacyclopropane and silatrimethylenemethane

Tetrahedron Letters,Vol.27,No.46,pp Printed in Great Britain REACTION 5625-5628,1986 OF SILYLENE ALKYLIDENESILACYCLOPROPANE Wataru Ando* Depart...

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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