An efficient stereospecific synthesis of olefins by the palladium-catalyzed reaction of grignard reagents with alkenyl iodides.

Tetr&edmn Letters No. 2, pp 191 - 194, 1976. PergamonPress. Printedir.Great Britain.

AN EFFICIENT STEREOSPECIFIC SYNTHESIS OF OLEFINS BY THE PALLADIUM-CATALYZED REACTION OF GRIGNARD REAGENTS WITH ALKENYL IODIDES.

Huu Phuong DANG and Gerard LINSTRUMELLE E.R. 12 du C.N.R.S., Laboratoire de Chimie de lyEcole Normale Superieure, 24, rue Lhomond, 75231 Paris Cedex 05, France. (Receivedin UK 7 November1977; accepted for publication 18 November 1977)

Direct coupling of two unlike alkenyl groups by the reaction of an alkenyl metal derivative with an alkenyl halide has proven difficult 1) . Although cuprates 2) might be expected to achieve the stereospecific coupling of two sp2 carbon atoms, vinylic cuprates have been found 3) not to react stereospecifically with vinylic iodides 4) .

YI

M

+

IWR -

pR

2

a)

M =

1(CuLi) 2

b)

M

MgBr

=

3

R=

, Cul

191

” =g “13

+ )q 4

No.

1-92

2

Thus, when treated with (E)-l-iodo-1-octene 2 5) in tetrahydrofuran, La

6) and Jb (with 10% copper iodide) 7) gave (70%) a mixture (80:20) of

olefins 3 and 4 8,9)_ We now report the stereospecific substitution of alkenyl iodides which proceeds under very mild conditions in high yield 8) with catalytic amounts of palladium complex 1,lO) . Thus, when (E)-l-iodo-1-octene se (1 equiv.) in benzene was treated sequentially with tetrakis (triphenylphosphine) palladium "I

(0.05 equiv.) and (El-1-propenyl-l-magnesium bromide 6e

(1.5 equiv.) in tetrahydrofuran at room temperature for 2 hr, pure (2,97%) (2Z,4E)-2,4-undecadiene 2e 8) was obtained in 87% yield. Several representative pure 1,3-dienes 8) Ja-e were efficiently prepared except in the case of the (Z,Z)-diene If which was formed along with another isomer (30%) 12).

R5

R5 R’

XMg

5

6

7

Table 1: Preparation of conjugated dienes 2.

R1 a

nCgH13

b

H

C

H

R2

R3

R4

R5

8) Yield (%)

H

H

H

H

81

nC6H1 3

H

H

H

75

nCgH13

CH3

H

H

84

H

82

CH3

87

d

nCgH13

H

CH3

H

e

nCgH13

H

H

H

H

H

f

H

nCgH13

CH3

79 12)

No.

193

2

The palladium-catalyzed cross-coupling reactions of vinylic iodides with a variety of Grignard reagents was then examined and found to occur with retention of configuration

(>,97%).

RMgX f Pd (P f’$$

8

5

Table 2: Preparation of ol.efins S. Rl

Yield (%) *)

R

R2

-~-nCgH13

H

nC2H5

H

nCgH13

nC2H5

H

nCgH13

'gH5

nCgH13 nCgH13 H

H

'gH5

H nCgH13

87 85 82 80

CH3C=C

83

CH3CX

80

The authors thank Dr. Sylvestre Julia for his interest in this work and the Centre National de la Recherche Scientifique for financial support.

References and Notes 1) For a review of coupling reactions via transition metal complexes, see: I( R. Noyori, in Transition Metal Orqanometallics in Organic Synthesis:' vol. 1, H. Alper, Academic Press, New York, 1976, chapter 2. 2) For a review, see: G.H. Posner, Orqanic Reactions --#

22, 253 (1975).

3) G. Linstrumelle, J. Millon and H.P. Dang, to be published. 4) However, one stereospecific coupling of a vinylic cuprate with a vinylic chloride has been reported: G. B&hi

and J-A. Carlson, Jaer.

Chem. Sot.,

194

113.

91, 5)

G.

6470

(1969).

Zweifel

6) Prepared Org.

2

and C.C. Whitney,

according

Syn., 55,

J. Amer.

Chem. .- Sot., _- 2,

to G. Linstrumelle,

103

J.K.

Krieger

2753

(1967).

and G.M. Whitesides,

(1976).

7) F. Derguini-Boumechal

and G. Linstrumelle,

Tetrahedron

Letters,

3225

(1976). 8) All

reactions

Grignard

were

reagents

for isolated

after

J. Amer.

1083,

A. Sekiya

2790

Chem.,

91,

given

are

gel column.

properties

13) gave

Bull.

and isomeric

(70 to 80%) a

S. Baba

A.O.

King,

N. Okukado

Coulson,

12) The exact

Inorg.

nature

13) J.F. Normant,

(1969); M. Julia

I. Moritani

Fr.,

and E. Negishi,

Syn., 13,

of the mixture

G. Cahiez,

121

(1976); J.F.

J. Amer. Chem.

253

Chem.

Fauvarque

683,

and

Chem - ,132,

SOC.,~,

Comm.,

(1975);

6729

(1976);

(1977).

investigation.

and J. Villieras,

(1974); A. Conunercon, J.F. Normant

1 (1977).

Chem

(1972).

is under

C. Chuit

ibid., 93,

(1976); J. Organomet.

and E. Negishi,

J. Org.

and S-1. Murahashi,

349

765

and M. Duteil

and R.F. Heck,

(1975); L. Cassar,

ibid.,ll8,

Sot. Chim.

(1977);

5118

(1973); H.A. Dieck

C39

and N. Ishikawa,

Cl7

269

Sot., 90,

(1975); M. Yamamura,

A. Jutand,

11,

silica

of

indicated.

(Z)-1-iodo-1-octene

Chem.

SQC. Chim. L,

J. Organomet.

11) D.R.

the yields

a short

spectral

1.5 equiv.

(ca. 30 : 70) of 3 and 4. -

lo- R. Heck,

40,

with

iodides;

through

satisfactory

if otherwise

9) In the same conditions,

Bull.

filtration

exhibited

(>/97%) except

mixture

of vinylic

for 1 equiv.

yields

All new compounds purity

carried out at room temperature

J. Organomet.

and J. Villieras,

Chem.,

ibid.,l28,