Selective poisoning of palladium-catalysed hydrogen-exchange reactions

Tetrahedron Letters No. 21, pp. 1349-1351, 1%3. Printed in Great Britain.

Pergamon Press Ltd.

POISOKIHG OF PALLADDJS-CATAIXSD -

EEIBXWE

RUCTI~

C.O. Hacdorvld ami S.S. W Divieion of coal ReMarch. C.S.I.It.O., Box l-75* mtwod.

mewsouth fi1.e

(Received 2 July 1%3) CAFMB

monoxidehae been ahoun (1) to eeleativeti PoiUm tb

pvleae

dth deuterim p

mer evaporated niohl

film.

exe-

ef

the ~rte of achy&@

of~I.ing~~Mkiognd~~~tbatoi~r~l~. We report eeleotive @dine oxchangeof -

+soaa

poleoaing of the palladim-cetaly8ed a

derlvatino

with

deutorinm

and eeleotlve

oxide,

exchangeof the eme compomdedth deuterirn oxide over unpoieowd nickel an kieeelguhr.

Whenthe degree of eelectivity in miiiciently

conTeabnoe of thee luaotione mbe capwMe

themwell euited for the prepcuation ef

lnbelled rith doutorim or tritlum in qeclfic In typical experbente ld

hi& the

poeitione.

palladim on chamoal (0.1 8) pm-

activated with b#ro.gm. the enbntra~ (0.3 II). a& deutorirn oxide (2 rl) mlsagitated

.¶t&

for -1hoUrCJlB

emcunted eealed tube&

Vader thee

conditione 8.11the hydlqem of baneene. toblene. the xylenes. ti

lthylbeneeae exchau@ extensively, * reealt coMietent with that of Elmta ar@ ueda (2) for the exohaageof p~leae e~rlmeate

in which pyridim

ortho to allqlgroup deuterlum

lxcluIngedmichmon

alow4tbn

oxide use replaced by pyAdi.ne-&..

ringthnnofthealkylbJdnwM &+&on&ieeelguhr

conditioM.

(0.02 ti) van added to the 6yhm.

eae muchelomr than that of the a-1

dth a &

u7lde.Y eidlar

the rod.

~xchsm@ of all

lwdxwem.

w

In hydro@U

whentha

the X-&S m

Muchelower oxchangeof the

aleo occurred whendeuterim odd. vae ueed cntaQet. which Is comietent with the work of

1349

Palladium-catalysed

1350

hydrogen-exchange

No.21

reactions

Bow010 acid

l

Calculate.3 frcm the dletrlbution and the a-

t

lbber

of reasidual protium detemiwd

by p...r.

deuterium content determIned meee epe&rometrioally.

of H atcme with retanied

of the mee-epectmwtrically doutemted qeciw.

exchan,p rates.

dotemined

relative

deduced from the pattern abundancee of

No.21

Palladium-catalysed hydrogen-exchange reactions

1351

Eirot.¶a&&da(2)ontbonicbl4b4uodao~of~lwnlMl deutniImoxM@.

Slower

axcbange

of the ortha

beenreported in the platimm-ca~ed the balobmmnea

then of the other r.ing&lrodam bmm emhang

of aodiubmmoate

(4) with deuterlvm oxide, thou& in theaa o-

selectivitgmn not aa great m allglboaseneswith deuterium p Ackmw~edmwnta

(3). ti

the

In the pmaent work, and in the moban@

of

omr evaporated nickel film (5).

-lie thaukDr. S. Stemhell for prorid-tb

protonmimetic msonaace data, lfr.M.J. key

for exp%sntal

~sistanuo,

and Mr. H.R. Ihpm, chief, Mvision of Coal Rowaroh, C.S.I.B.O.,for support and OnC~t..

(1) J.M. Phillips. E. Crawford and C. K-ball. &uuu&.~rn187~%3). (2) K. Hirote and T. Ueda,Bull. Chew Sot. Jaa

2,

228 (1%2).

(3) J.L. Cer!lett,L.J. Henderson, Y.A. Sollich and C.van D. Tiers, Tetrahedronbtterg Ko.15, 516 (l%l). (4) J.L. Carnett and W.A. Sollich. Au&ml. (5) E. Crawford and C. Komball..purdav.

J. Chq.

&, &.

441

(1961).

2452 (1962).