Fluoroalicyclic derivatives of germanium and tin

IHORG.

HUCL.

CHEM.

LETTERS

Vol.

4,

pp.

205-207,

1968.

Pergamon

Press.

Printed

In

Great

Bdtoln.

Fluoroalicyclic Derivatives of Germanium and Tin W. R. Cullen and M. C. Waldman Chemistry Department, University of British Columbia Vancouver, Canada (Received 18 Januo~ 1~8)

Novel l-trifluoromethyl-3,3-difluorocyclopropenyl

derivatives of arsenic,

silicon, and germanium have been described recently (1).

We now wish to report

the synthesis of related tin compounds by a similar route. CF3C~CH + CH3MgI + CF3C~CMgl + CH 4

(i)

(CH3)3SnCI + CF3C~CMgl ~ (CH3)3SnC~CCF3 + MgICl

(2)

(CH3)3SnC~CCF3 + (CH3)3SnCF3 + (CH3)3Sn ~ C F

3 + (CH3)3SnF

(3)

V F2 Trifluoropropyne

(8.04 g) was condensed into a Carius tube containin~ a solu-

tion of the Grignard reagent made from magnesium (7.0 g) and iodomethane (18 g) in anhydrous ether (30 ml).

The tube was sealed and shaken at 20 ° for 24 hours

The contents of the tube were then added, using a syringe, to 27 g of trimethyltin chloride in ether (40 ml).

The solution was refluxed for 3 hours.

Distillation gave a 64% yield of the trifluoropropynyltin compound, b.p. 125 °. Lower yields are obtained when Grignard reagents formed from iodobenzene or bromoethane are used in the reaction of eq. I, (2). The cyclopropenyltin derivative was obtained in 39% yield from a reaction in the gas phase at ]45 ° (eq. 3).

Seyferth and coworkers (3) have recently reported comparable yields

of cyclopropyl derivatives of silicon, germanium, and tin from an iodide ion induced addition of difluorocarbene, from trimethyltrifluoromethyltin, derivatives of these elements. peratures (~80°).

to vinyl

Reaction takes place in solution at lower tem-

A cyclopropylarsine has been prepared from a gas phase addi-

tion of difluorocarbene

(I) and we have also found that a good yield (41%) of

2,2-difluorocyclopropyltrimethylsilane

can be obtained from the vinylsilane 2o5

204

FLUOROA~LICYCLIC DERIVATIYES

V.I. 4, No. 4

by r e a c t i o n with the carbene source in the gas phase.

Dimethylbis(3,3,3-

t r i f l u o r o p r o p y n y l ) t i n , which is prepared from d i m e t h y l t i n d i c h l o r i d e , r e a c t s with two moles o f t r i m e t h y l t r i f l u o r o m e t h y l t i n to give the b i s ( c y c l o p r o p e n y l ) t i n compound (eq. 4).

(CH3)2 (CH3)2Sn(C~CCF3) 2 + 2(CH3)3SnCF 3 ~ C F 3 ~ ,

Sn ~ : : : ~ C F 3 + 2(CH3)3SnF

V

V

F2

(4)

F2

All the tin compounds are hydrolyzed by water at 20 ° , the propynyl compounds yielding the parent acetylene in high yield and the cyclopropenyl derivatives l-trifluoromethyl-3,3-difluorocyclopropene.

This same cyclopropene

is also obtained from the reaction of 3,3,3-trifluoropropyne and trimethyltrifluoromethyltin.

Its 19F n.m.r, spectrum shows a quartet of doublets at

102.5 p.p.m, due to the CF 2 group (JHF = 1.25, JFF = 2.8 c.p.s.) and a triplet of doublets at 63.2 p.p.m, due to the CF 3 group (JHF = 0.4 c.p.s.)(4).

The

infrared spectrum is very similar to those of the other cyclopropenyl derivatires (I).

The double bond absorbs at 1730 cm

-I

We also wish to report the synthesis of some corresponding derivatives of germanium,

(CH3)3GeC~CCF3,

(CH3)2Ge(C~CCF3)2, and (CH3)3GeC=C(CF3)CF 2.

Trimethyl-3,3,3-trifluoropropynylgermane diazomethane at IS0 ° to give a pyrazole.

reacts with bis(trifluoromethyl)The isomer indicated in eq. S is

probably the one that is produced.

(CH3) 3GeC~CCF3 + (CF3)2CN2

~

(CH3) 3Gex~=ctCF3u

(5)

N" ~C (CF3) 2 \N / A similar pyrazole is obtained by reacting hexafluorobutyne-2 with the same diazo compound.

Tetrakis(trifluoromethyl)cyclopropene

also seems to be formed.

It has been reported (S) that bistriflueromethyldiazomethane

adds to butyne-2

to give a pyrazole and that the pyTazole eliminates nitrogen on heating to yield the cyclopropene.

Vol. 4, Mo. 4

FLUOROALICYCLIC

DERIVATIVES

207

Acknowledgments Financial assistance gratefully

acknowledged.

d i a z o m e t h a n e were c a r r i e d tical

from t h e N a t i o n a l R e s e a r c h C o u n c i l o f C~nada i s Some p r e l i m i n a r y r e a c t i o n s

with bis(trifluoromethyl)-

o u t w h i l s t one o f us (W.R.C.) was s p e n d i n g a s a b b a -

year at the University of Bristol.

F. g. A. S to n e f o r h i s h o s p i t a l i t y

He would l i k e t o thank P r o f e s s o r

and c o n t i n u e d i n t e r e s t .

References I.

W. R. C u l l e n and W. R. L e e d e r , I n o r g . Chem., ~ ,

2.

Dimethylaminotrimethyltin

1004 (1966).

and 3,3,3=trifluoropropyne

20 ° but no prepynyltin compound is produced.

readily 'react at

This result should be com-

pared with those of Jones and Lappert, J. Organometal.

Chem. ~, 295 (1965),

who obtained high yields of hydrocarbon alkynyltin compounds from reactions of this sort. 3.

D. Seyfe~th, H. Dertouzos, R. Suzuki, and J. Y.-P. Mui, J. Org. Chem., 32,

2980 (1967). 4.

Chemical shifts are upfield from internal CFCI 3.

5.

D. M. Gale, W. J. Middleten and C. G. Krespan, J. Am. Chem. Soc., 88, 3617 (1966).