Diels-Alder Reaction in the Presence of Zeolite
Junes Ipaktschi
Institut für Organische Chemie der U niversität, Heinrich-Buff-Ring 58, D-6300 G ießen
Z. N aturforsch. 41b, 496—498 (1986); received O ctober 24. 1985 / January 9, 1986
Cycloaddition R eactions, C opper(I)-zeolite
Cu(I) ion exchanged Y-zeolite catalyzed Diels-Alder reaction of furan, cyclopentadiene,
1.3-cyclohexadiene, isoprene and 2.3-dimethylbutadiene with a series of acrylic and acetylenic
dienophiles is reported. The cycloadducts are obtained in high yield and selectivity.
Rate acceleration and selectivity enhancement of
organic reactions such as D iels-A lder or Ene reac­
tions using water [ 1 ] as a solvent or clay supported
reagents [2 ] have recently attracted much interest.
The underlaying reason for their influence on the
reaction rates and selectivity, has been ascribed to
hydrophobic association of the reactants, as in the
case of water, or the presence of water and Lewis
acid on the surface of the layered structure of clay
[1—3], Principly, there exists also the possibility of
topological controlled, catalyses of organic reaction
within the framework of zeolites.
Z eolites, which are crystalline aluminosilicates of
usually w ell-defined structures, differ from clays in
one very important respect — their rigid three-dimensional framework contains a system of channels
and cavities that do not allow appreciable swelling to
occur [4],
In this study we have investigated the cycloaddi­
tion reactions of a series of dienes with oxygen-con­
taining dienophiles in the presence of the Cu(I) ion
exchanged Y -zeolite [5].
Cu(I) ion exchanged Y -zeolite was prepared by
the partial exchange of the sodium ions in the Yzeolite against Cu(II) ions and subsequent reduction
by carbon m onoxid at 300 °C. In the reduction pro­
cess of the Cu(II) ions equimolar amounts o f pro­
tones are produced. The zeolite prepared by this
method has in the supercage two catalytic active cen­
ters at disposal: 1) Cu(I) ions as a Lewis acid as well
as an electron donor center and 2 ) the protones as a
Br0 nsted acid sites. It was therfore to be expected
that catalytic cycloaddition reaction of dienophiles
such as acrylic acid derivatives would be specially
affected. In fact a com parison of the data in Table I
shows for exam ple that the otherwise sluggish reac­
tion of furan and dienophiles like m ethylvinylketone
or acrolein are greatly accelerated in the presence of
the Cu(I) Y -zeolite.
Whereas the Cu(I) Y -zeolites are, in respect to
rates, yields and stereoselectivities, comparable to
clay minerals supported Lewis acids [2] or hydrophobic reaction conditions in aqueous suspensions,
they present another attractive alternative to the use
(2 .5 : 1 )
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of the drastic high pressure conditions (15000 atm)
used to prom ote D iels-A ld er reactions with furans.
The generality o f this m ethod of enhancing cycloadditon reaction rates and regioselectivity is further ex­
emplified by the reactions of various non cyclic
dienes with a number of dienophiles (c/. Table II).
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J. Ipaktschi • Diels-Alder Reaction in the Presence of Zeolite
497
Table I. Diels-A lder reaction of cyclic 1.3-dienes in presence of Cu(I) Y-zeolite.
Diene
Dienophile
Conditions
Yields (% )
exo/endo
Reference
Furan
Methylvinylketone
73
2.5:1
This work
Furan
Furan
Methylvinylketone
Methylvinylketone
48
60
ca. 1
2.2:1
[V]
[2c]
Furan
Acrolein
31
5:1
This work
Furan
Furan
Acrolein
Acrolein
53
65
ca. 1
5:1
[7]
[2c]
Cyclopentadiene
Methylvinylketone
84
1:24
This work
Cyclopentadiene
Methylvinylketone
98
1:13.5
[2b]
Cyclopentadiene
1.3-Cyclohexadiene
Methylvinylketone
Acrolein
80
76
1:21.4
1:33
[lc]
This work
1.3-Cyclohexadiene
Acrolein
Cu(I)-zeolite, C H 2C12
0 °C, 48 h
15000 atm ; 4 h
Fein-doped bentonite
-4 3 °C, 6 h
Cu(I)-zeolite
0 °C. 12 h
15000 atm ; 4 h
AlCl3-doped bentonite
—43 °C, 15 min
C u(I)-zeolite, CH,C12
0 °C, 1 h
F enI-doped
m ontm orillonite
C H 2C12; 0 °C, 2 h
H 2Ö 3 h
C u(I)-zeolite
rt 1 h
8 h, 100 °C
80
1:9
[8]
Diene
Dienophile
Isoprene
Acrolein
Conditions
Cu(I)-zeolite
0 °C, 12 h
Isoprene
Methylvinylketone Cu(I)-zeolite
0 °C, 3 h
Isoprene
Methylacrylate
Cu(I)-zeolite
20 °C, 12 h
Isoprene
Dimethylacetylene- Cu(I)-zeolite
Dicarboxylate
20 °C, 12 h
2.3-Dimethylbutadiene Acrolein
Cu(I)-zeolite
0 °C, 24 h
2.3-Dimethylbutadiene Methylvinylketone Cu(I)-zeolite
0 °C, 24 h
Experimental
Preparation o f Cu(I) Y -zeolite
A suspension of 26 g L Z —Y 52 zeolite [9] in 70 ml
water is acidified with 2N H 2S 0 4 to PH 6 —7. The
zeolite is filtered and treated at 40 °C for 2 h with
150 ml of a 0.25 M copper (II) acetate solution. A f­
ter the mixtur is filtered and washed several times
with dist. H 20 , the ion exchange operation is re­
peated. The remaining light blue powder is dryed at
100 °C for 24 h. Analysis shows that the zeolite con­
tains 5.98% Cu(II) ion. Reduction of Cu(II) zeolite
Yield (% )
Isomeric
ratio
65
99.5:0.5
83
24:1
51
24:1
Table II. Diels-Alder reac­
tions of acyclic 1.3-dienes in
presence of Cu(I) Y-zeolite.
71
68
87
is performed at 300 °C in a slow stream of carbonmonoxid for 12 h to yield the colorless Cu(I) Yzeolite.
All D iels-A lder reactions reported in Table I and
II were performed analog to the synthesis of 4m ethyl-3-cyclohexene-l-carboxaldehyde.
4-M ethyl-3-cyclohexene-l-carboxaldehyde
1.0 g of the Cu(I) Y -zeolite and 5 ml of dry CH 2C12
were placed in a 25 ml round-bottom ed flask. A so­
lution of 680 mg (10 mmol) o f isoprene and 560 mg
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498
(1 0 mmol) of acrolein in 5 ml of C H 2C12 is added, via
syring dropwise with stirring at 0 °C over 30 min
(exothermic reaction!). The mixture is stirred at 0 °C
for 12 h. A fter evaporation of the solvent, the re­
sidue is extracted in a Soxhlet apparatus with pentane. The solvent is removed by rotary evaporation
and the residue distilled in a bulb to bulb distillation
apparatur to yield a colorless liquid, bp. 70 °C
(12 mm) Lit. [10], bp. 64—65 °C (10 m m), yield
810 mg (65% ). GC and *H N M R analysis shows the
presence of only one adduct. 'H NM R (CDC13,
[1] a) D. R. Williams, R. D. G aston, and I. B. H o rto n ,
III, T etrahedron 26, 1391 (1985);
b) P. A. G rieco, P. G arner, K. Yoshida, and C. H uff­
man, T etrahedron Lett. 24, 3807 (1983);
c) R. Breslow, U. M aitra, and D. R ideout, T e tra ­
hedron Lett. 24, 1901 (1983).
[2] a) A. Cornelis and P. Laszlo, Nachr. Chem. Techn.
Lab. 33, 202 (1985);
b) P. Laszlo and J. Luccetti, T etrahedron Lett. 25,
2147 (1984);
c) P. Laszlo and J. Lucchetti, T etrahedron L ett. 25,
4387 (1984);
d) J. F. Foudier and A. Foucaud, T etrahedron Lett.
25, 4375 (1984); H. Parlar and R. Baum ann, Angew.
Chem. 93, 1114 (1981).
[3] T. J. Pinnavaia, Science 220, 365 (1983).
[4] J. A. Rabo (ed.): Zeolite Chemistry and Catalysis,
American Chemical Soc. W ashington D. C. 1976.
[5] C u(II) and Cu(I) ions are used as catalysis for the
Diels-A lder reaction [6]. In a control experim ents
J. Ipaktschi • Diels-A lder Reaction in the Presence of Zeolite
250 MHz): Ö = 9.68 (s, 1H, C - H ) , 5.40 (bs, 1H,
Ö
C3- H ) , 2.41 (m, 1H, C j - H ) , 2.19 (bs, 2 H , C 2- H ) ,
1.99 (bs, 2 H , C 5 - H ) , 1.92 (m, 1H, C 6- H ) , 1.70 (m,
1H, Q - H ) , 1.62 (s, 3 H , CH3).
This work was performed during a sabatical leave
at the University o f California, Berkeley, in the
laboratorium of Professor W. G. Dauben to whom I
am grateful for his kind hospitality and to Deutsche
Forschungsgemeinschaft for financial support.
[6]
[7]
[8]
[9]
[10]
isoprene and methylvinylketone in presence of copp er(II) acetate. H 20 in methylenechloride at 0 °C
after 5 h no reaction was observed and in the presence
of copper(I) chloride in methylenechloride at 0 °C
after 3 h only 1.5% cycloadduct was detected. Fur­
therm ore, the reaction of 2.3-dimethylbutadiene and
acroleine in the presence of copper(I) tetrafluoroborate after 4 h at 0 °C resulted in extensive poly­
m erisation.
J. A. M oore and J. E. M. Partain, III, J. Org. Chem.
48, 1105 (1983); P. Vieira and P. Vogel, Helv. Chim.
A cta 65, 1700 (1982).
W. G. D auben and H. O. K rabbenhaft, J. Am. Chem.
Soc. 98, 1992 (1976).
A. K rantz and C. Y. Liu, J. Am. Chem. Soc. 95, 5662
(1973).
A sample of L Z -Y 5 2 zeolite was gratefully supplied
by the Union Carbide.
D. A. McCrae and L. Dolby, J. Org. Chem. 42, 1607
(1977).
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