Ene hydroperoxidation of isobutenylarenes within dye-exchanged zeolite Na-Y: Control of site selectivity by cation-arene interactions

Article abstract of DOI:10.1021/jo020599g

The site selectivity in the singlet oxygen ene reaction of several deuterium-labeled isobutenylarenes depends on the position and the electronic nature of the aryl substitutents. For example, 1-(4-trifluoromethylphenyl)-2-methylpropene gives 82% twin sele

Full text of DOI:10.1021/jo020599g

En e Hyd r op er oxid a tion of Isobu ten yla r en es w ith in
Dye-Exch a n ged Zeolite Na -Y: Con tr ol of Site Selectivity by
Ca tion -Ar en e In ter a ction s
Manolis Stratakis,* Constantinos Rabalakos, Giannis Mpourmpakis, and George E. Froudakis
Department of Chemistry, University of Crete, 71409 Iraklion, Greece
stratakis@chemistry.uoc.gr
Received September 11, 2002
The site selectivity in the singlet oxygen ene reaction of several deuterium-labeled isobutenylarenes
depends on the position and the electronic nature of the aryl substitutents. For example, 1-(4-
trifluoromethylphenyl)-2-methylpropene gives 82% twin selectivity whereas the isomeric 1-(2-
trifluoromethylphenyl)-2-methylpropene gives 68% twix selectivity. If photooxygenation of these
CF3-substituted compounds is carried out in solution, the opposite selectivity trends are found. On
the basis of DFT calculations, these results are rationalized in terms of oxygen-cation and cation-
arene interactions.
SCHEME 1. In tr a zeolite P h otooxygen a tion of
Isobu ten yla r en es
In tr od u ction
The dye-sensitized intrazeolite photooxygenation of
organic compounds has attracted recently considerable
attention1 due to the significant enhancement of product
selectivity. For trisubstituted alkenes, the ene reaction
is regioselective with preferential double-bond formation
at the more substituted carbon of the double bond. In
addition, the “cis effect” selectivity in the photooxygen-
ation of trisubstituted alkenes does not operate within
the zeolite.2 On the other hand, the regioselectivity in
the intrazeolite photooxygenation of electron poor alkenes
is very close to that found in solution.3
SCHEME 2. Syn th esis of La beled Alk en es 5a -j
Recently, we reported4 that photooxygenation of isobute-
nylarenes within thionin-supported zeolite Na-Y is
chemoselective, affording the ene allylic hydroperoxides
as major or only products (Scheme 1). Although photo-
oxygenation of these compounds in solution gives mainly
oxygenated products arising from [4 + 2] or [2 + 2]
addition to the arylalkene,5 within zeolite Na-Y these
products are minor or even absent. It was proposed4 that
Na+ coordination to the aryl ring destabilizes the transi-
tion state for the formation of the zwitterionic intermedi-
ate, relative to the perepoxide intermediate; the zwitter-
ionic intermediate6 is the precursor of the Diels-Alder
or the [2 + 2] oxygenated products, while the perepoxide
leads to the ene products.
Resu lts
(1) (a) Ramamurthy, V.; Lakshminarasimhan, P. H.; Grey, C. P.;
J ohnston, L. J . J . Chem. Soc., Chem. Commun. 1998, 2411-2418. (b)
Zhou, W.; Clennan, E. L. J . Am. Chem. Soc. 1999, 121, 2915-2916.
(c) Clennan, E. L.Tetrahedron 2000, 56, 9151-9179.
(2) (a) Stratakis, M.; Froudakis, G. Org. Lett. 2000, 2, 1369-1372.
(b) Clennan, E. L.; Sram, J . P. Tetrahedron 2000, 56, 6945-6950. (c)
Stratakis, M.; Nencka, R.; Rabalakos, C.; Adam. W.; Krebs, O. J . Org.
Chem. 2002, 67, 8758-63.
In this paper, we report a site-selectivity study of the
ene reaction in the intrazeolite photooxygenation of the
stereoselectively labeled 1-aryl-2-methylpropenes 5a -j.
The preparation of alkenes 5a -j was accomplished in
93-99% purity for the E configuration following known
literature procedures2a,c (Scheme 2). The only change is
that instead of forming the labile allylic mesylates-d2, the
allylic alcohols-d2 were transformed to the more stable
(3) Clennan, E. L.; Sram, J . P.; Pace, A.; Vincer, K.; White, S. J .
Org. Chem. 2002, 67, 3975-3978.
(4) Stratakis, M.; Rabalakos, C. Tetrahedron Lett. 2001, 42, 4545-
4547.
(5) Frimmer, A. A.; Stephenson, L. M. In Singlet Oxygen. Reactions,
modes and products, Frimer, A. A., Eds.; CRC Press: Boca Raton, 1985;
pp 120-133.
(6) (a) Clennan, E. L. Tetrahedron 1991, 47, 1343-82. (b) Adam,
W.; Prein M. Acc. Chem. Res. 1996, 29, 275-83.
10.1021/jo020599g CCC: $25.00 © 2003 American Chemical Society
Published on Web 02/25/2003
J . Org. Chem. 2003, 68, 2839-2843
2839

Stratakis et al.
TABLE 1. Site Selectivity in th e P h otooxygen a tion of Isobu ten yla r en es 5a -j
a
b
The values were corrected for 100% E geometrical purity of the deuterium-labeled alkenylarenes. Photooxygenation in CH2Cl2,
with methylene blue as sensitizer. c The twin/ twix selectivity is solvent dependent (ref 10). Reference 11. e The reaction mixture was
d
very complex, and the ene adduct was formed in <10% relative yield for the twin/ twix selectivity to be determined accurately.
allylic chlorides-d2 by reacting with N-chlorosuccinimide
thionin-supported Na-Y. The tube was irradiated at 0 °C
for 4-5 min under a constant flow of oxygen. After
extractive workup, the products were analyzed by 1H
NMR spectroscopy. It is remarkable that all substrates
had been consumed after 5 min of irradiation, whereas
the same amount of the alkenylarenes (∼10 mg) in
solution (CH2Cl2, with methylene blue as sensitizer)
require reaction time of one to several hours to go to
completion, and the product mixture is very complex as
well. The mass balances, as estimated by GC using
2-phenylethanol or 2,6-di-tert-butyl-p-cresol as calibration
compounds, were 86-94% except for 5e (mass balance
78%).
and dimethyl sulfide, according to a literature procedure.7
All arylalkenes afford upon photooxygenation within
thionin-supported zeolite Na-Y, the ene allylic hydro-
peroxides8 as the major or only products. In a typical
experiment, 10 mg of the alkenylarene dissolved in 10
mL of hexane was added to a tube containing 1 g of dry
(7) Grdina, M. B.; Orfanopoulos, M.; Stephenson, L. M. J . Org.
Chem. 1979, 44, 2936-2938.
(8) The allylic hydroperoxides were reduced with PPh3 to the
corresponding alcohols, whose spectral data are identical to the alcohols
produced by 2-propenylmagnesium bromide addition to the arylalde-
hydes 1a -j.
2840 J . Org. Chem., Vol. 68, No. 7, 2003

Ene Hydroperoxidation of Isobutenylarenes
CHART 1
The intrazeolite photooxygenation results are pre-
sented in Table 1. For comparison, the site selectivity for
the ene pathway in the photooxygenation of the same
alkenes in solution is presented. In solution, the ene
allylic hydroperoxides were formed as minor adducts, but
we were able to either isolate them by column chroma-
tography or calculate the ratio of twin/ twix9 selectivity
from the crude reaction mixture, if the signals of the ene
products in the region of 4.5-6.0 ppm were not overlap-
ping with other absorptions. In the intrazeolite photo-
oxygenation of substrates 5a -d , where Ar ) phenyl (5a ),
p-tolyl (5b), p-isopropylphenyl (5c), and o-tolyl (5d ), the
twin/ twix methyl group reactivity is almost identical,
with the twix methyl group being slightly more reactive.
Similar twin/ twix reactivities are found in solution. The
preference for twix reactivity, if photooxygenation is
carried in solution, has been rationalized10 for the case
of 5a in terms of attractive oxygen-arene interactions
during the formation of the intermediate perepoxide. For
the p-CF3-substituted styrene 5f, however, very different
selectivities were found in the zeolite compared to the
solution.
Although in solution the twix reactivity is 74%, within
Na-Y, it drops to 18%. Contrary to 5f, for the o-CF3
substituted styrene 5h , the twix selectivity in solution
is only 23%, while in Na-Y it increases to 68%. For the
m-CF3-substituted styrene 5g, similar regioselectivities
were found in solution and within Na-Y (twin/ twix ∼
1/2). For alkenes 5e, 5i, and 5j, where the substitutents
are 1-naphthyl, p-fluoro, and p-methoxy, respectively,
reactivities of approximately twin/ twix ) 60/40 are found
within the zeolite, while in solution, the twix methyl
group is more reactive.
Discu ssion
Before analyzing the intrazeolite regioselectivity re-
sults, we would like to present our theoretical calcula-
tions on the interaction of Na+ to some isobutenylarenes.
Sodium cation is well-known to bind strongly to the π
face of aromatics,12 and this coordination is likely to affect
the regioselectivity results in the photooxygenation of the
isobutenylarenes within Na-Y. The theoretical treatment
of the neutral and the sodium-bound molecules involved
density functional theory (DFT)13 with the three-param-
eter hybrid functional of Becke and the use of Lee-
Yang-Parr correlation functional (B3LYP). The level of
the calculations used herein was B3LYP/6-31G*. For 5a ,
the cation binds on top and in the middle of the phenyl
group at a distance of 4.088 Å from the middle of the
alkene double bond (Chart 1). Also, the phenyl group
forms a dihedral angle of 29° with respect to the π system
of the double bond. For alkene 5f, in the lowest energy
minimum structure the Na+ has shifted from the middle
of the aryl ring to interact with the fluorine atoms.14 The
distance of the Na+ from the middle of the alkene double
bond is 5.027 Å and 2.295 Å from the closest F atom
(Chart 1). A second minimum less stable by 0.6 kcal/mol
was also found in which the Na+ is located in the cone of
the three fluorine atoms at a distance of 2.48 Å from each
F (see the Supporting Information). For 5h , the -CF3
functionality shifts significantly the binding site. The Na+
is located at a distance of only 2.83 Å from the middle of
the double bond (Chart 1). Finally, for substrates 5i and
5j where the substituents are p-fluoro and p-methoxy,
respectively, the DFT calculations have shown that apart
from the binding site of Na+ on the middle of the aryl
ring, coordination to the heteroatoms is also significant.
The minima in which the Na+ is bound to the hetero-
atoms are less stable by 1.5 kcal/mol for 5i, and 1.2 kcal/
mol for 5j,15 compared to the structures where the cation
sits on top of the aryl ring (see the Supporting Informa-
tion).
(9) For the terminology twin and twix, see: Adam, W.; Bottke, N.;
Krebs, O. J . Am. Chem. Soc. 2000, 122, 6791-6792.
(10) Stratakis, M.; Orfanopoulos, M.; Foote, C. S. J . Org. Chem.
1998, 63, 1315-1318.
(11) Alberti, M.; Vougioukalakis, G.; Orfanopoulos, M. Tetrahedron
Lett. 2003, 44, 903-905.
(12) Ma, J . C.; Dougherty, D. A. Chem. Rev. 1997, 97, 1303-1324.
(13) Frisch, M. J .; Trucks, G. W.; Schlegel, H. B.; Gill, P. M. W.;
J ohnson, B. G.; Robb, M. A.; Cheeseman, J . R.; Keith, T.; Petersson,
G. A.; Montgomery, J . A.; Raghavachari, K.; Al-Laham, M. A.;
Zakrzewski, V. G.; Ortiz, J . V.; Foresman, J . B.; Cioslowski, J .;
Stefanov, B. B.; Nanayakkara, A.; Challacombe, M.; Peng, C. Y.; Ayala,
P. Y.; Chen, W.; Wong, M. W.; Andres, J . L.; Replogle, E. S.; Gomperts,
R.; Martin, R. L.; Fox, D. J .; Binkley, J . S.; Defrees, D. J .; Baker, J .;
Stewart, J . P.; Head-Gordon, M.; Gonzalez, C.; Pople, J . A. Gaussian
94, revision D.4; Gaussian, Inc.: Pittsburgh, PA, 1995.
(14) The strong interaction of Na+ to fluorinated compounds within
zeolite Na-Y is well known. For example see: Grey, C. P.; Poshni, F.
I.; Gualtieri, A. F.; Norby, P.; Hanson, J . C.; Corbin, D. R. Lim, K. H.;
Grey, C. P. J . Am. Chem. Soc. 1997, 119, 1981-1989.
J . Org. Chem, Vol. 68, No. 7, 2003 2841

Stratakis et al.
SCHEME 3. P ossible Tr a n sition Sta tes in th e
In tr a zeolite F or m a tion of th e En e P r od u cts for
Alk en es 5a ,f
the twix methyl group. This selectivity in solution, which
is the opposite to that found for all other substrates in
this study, could be rationalized considering the severe
electronic repulsions of the fluorine atoms to the oxygen
approaching the more substituted side of the alkene.
For substrates 5i and 5j, the substituents p-fluoro and
p-methoxy compete with the phenyl ring for binding to
the cation. We assume that the average binding site must
be between the center of the arene and the F or O atoms,
respectively, but not as shifted from the center of the aryl
ring, as in the case of the p-CF3-substituted styrene 5f.
In other words, the distance of the cation from the styrene
double bond has increased, and formation of the per-
epoxide intermediate facing toward the more substituted
side of the alkene is less favorable compared to 5a , but
more favorable compared to 5f. Thus, intermediate values
for the twix selectivity, between 5a and 5f, were found
for 5i and 5j. In the case of the naphthyl-substituted
compound 5e, we postulate that coordination of Na+ to
the naphthalene moiety is also the driving force, for the
reaction to occur preferentially, within Na-Y, at the twin
position. Again, as proposed for 5i and 5j, the average
binding site is expected to have shifted from the middle
of the aryl ring which is next to the alkene double bond.
In conclusion, we have found that the site selectivity
in the ene reaction of several isobutenylarenes within
zeolite Na-Y can be correlated to the distance of the
alkene double bond from the binding site of the Na+ with
the substrate. The longer the distance, the lower reactiv-
ity of the twix methyl group, due to the reduction of the
favorable oxygen-cation interactions during the forma-
tion of the intermediate perepoxide in which oxygen is
oriented toward the more substituted side of the alkene.
With the exception of the ortho-substituted substrate
5h , all other alkenylarenes show a preference for twix
allylic hydrogen atom abstraction if photooxygenation is
carried out in solution. Favorable oxygen-arene inter-
actions might be the driving force for this selectivity as
postulated for the case of 5a .10 Within the zeolite Na-Y,
however, we propose that the reactivity of the twin and
twix methyl groups is controlled (i) by electrostatic
interactions of Na+ to the styrenes and (ii) by electrostatic
interactions of the negatively charged oxygen of perep-
oxide to the Na+.16 Considering the nonsubstituted
styrene 5a , the relative higher stability of TS1 (formation
of the twix product) in Scheme 3, compared to the TS2
(formation of the twin product), may arise from the
favorable electrostatic interactions between the nega-
tively charged oxygen of perepoxide and the cation. The
same is expected to be true for styrenes 5b-d . By placing
a CF3 substitutent at the para position in 5a (substrate
5f), interaction of Na+ to the highly electronegative
fluorine atoms shifts the binding site closer to the CF3
functionality. The distance between the Na+ and the
double bond of the alkene is higher (Chart 1), therefore,
than the stabilizing electrostatic interaction between the
oxygen of the perepoxide and the cation less important
(transition state TS3 in Scheme 3). Thus, the reaction
occurs preferentially at the twin methyl group via transi-
tion state TS4.
On going to the ortho-substituted CF3-styrene 5h , the
binding of Na+ to the fluorine atoms shifts the cation very
close to the alkene double bond, thus favoring electro-
static interaction of the Na+ to the perepoxide in which
oxygen is directed toward the more substituted side of
the alkene (68% twix selectivity). It is notable that the
photooxygenation of 5h in solution proceeds at a remark-
ably slow rate (less than 5% conversion after 30 min).
Yet, we were able to integrate the appropriate peaks in
the crude reaction mixture and found that the twin
methyl group is 3-4 times more reactive compared to
Exp er im en ta l Section
Nuclear magnetic resonance spectra were obtained on a 500
MHz instrument. Isomeric purities were determined by 1H
NMR, 13C NMR, and GC on an HP-5 capillary column. All
spectra reported herein were taken in CDCl3. Preparation of
the labeled alkenylarenes 5a 10 and 5j17 has been described
from earlier studies in our lab, while 5b was a gift from Mrs.
M. Alberti.11
The 1H NMR data of the esters 2c-i are as follows. 2c: 7.68
(s, 1H), 7.36 (d, 2H, J ) 8.0 Hz), 7.26 (d, 2H, J ) 8.0 Hz), 3.82
(s, 3H), 2.94 (septet, 1H, J ) 7.0 Hz), 2.14 (s, 3H), 1.27 (d, 6H,
J ) 7.0 Hz). 2d : 7.76 (s, 1H), 7.20-7.23 (m, 4H), 3.84 (s, 3H),
2.29 (s, 3H), 1.97 (s, 3H). 2e: 8.21 (s, 1H), 7.85-7.95 (m, 3H),
7.49-7.56 (m, 3H), 7.41 (d, 1H, J ) 7.1 Hz), 3.81 (s, 3H), 2.08
(s, 3H). 2f: 7.58 (s, 1H), 7.55 (d, 1H, J ) 8.0 Hz), 7.45 (d, 1H,
J ) 8.0 Hz), 3.82 (s, 3H), 2.09 (s, 3H). 2g: 7.69 (s, 1H), 7.63
(s, 1H), 7.47-7.59 (m, 3H), 3.84 (s, 3H), 2.12 (s, 3H). 2h : 7.86
(s, 1H), 7.72 (d, 1H, J ) 7.8 Hz), 7.57 (t, 1H, J ) 7.2 Hz), 7.44
(t, 1H, J ) 7.2 Hz), 7.33 (d, 1H, J ) 7.8 Hz), 3.85 (s, 3H), 1.93
(s, 3H). 2i: 7.64 (s, 1H), 7.37 (dd, 2H, J HH ) 8.5 Hz, J HF ) 5.7
Hz), 7.08 (dd, 2H, J HH ) 8.5 Hz, J HF ) 8.5 Hz), 3.82 (s, 3H),
2.10 (s, 3H).
The 1H NMR data of the allylic alcohols-d2 3c-i are as
follows. 3c: 7.23 (d, 2H, J ) 8.0 Hz), 7.20 (d, 2H, J ) 8.0 Hz),
6.50 (s, 1H), 2.91 (septet, 1H, J ) 7.0 Hz), 1.93 (s, 3H), 1.64
(br s, 1H), 1.26 (d, 6H, J ) 7.0 Hz). 3d : 7.16-7.20 (m, 4H),
6.52 (s, 1H), 2.26 (s, 3H), 1.76 (s, 3H), 1.57 (br s, 1H). 3e: 7.98
(m, 1H), 7.88 (m, 1H), 7.78 (d, 1H, J ) 8.0 Hz), 7.46-7.52 (m,
3H), 7.35 (d, 1H, J ) 8.0 Hz), 6.99 (s, 1H), 1.79 (s, 3H), 1.60
(br s, 1H). 3f: 7.58 (d, 2H, J ) 8.2 Hz), 7.37 (d, 2H, J ) 8.2
(15) In agreement with the current results, almost isoenergetic
minima for aryl versus methoxy binding were calculated for the Na+
interaction to 4′-methoxyacetophenone. We thank Professor V. Rama-
murthy for a prepublication copy of their work. Shailaja, J .; Laksh-
minarasimhan, P. H.; Pradhan, A.; Sunoj, R. B.; J ockusch, S.;
Karthikeyan, S.; Uppili, S.; Chandrasekhar, J .; Turro, N. J .; Rama-
murthy, V. J . Phys. Chem. A 2003, 107, in press.
(16) Clennan, E. L.; Sram, J . P. Tetrahedron Lett. 1999, 40, 5275-
5278.
(17) Stratakis, M.; Hatzimarinaki, M.; Froudakis, G. E.; Orfanopo-
ulos, M. J . Org. Chem. 2001, 66, 3682-3287.
2842 J . Org. Chem., Vol. 68, No. 7, 2003

Ene Hydroperoxidation of Isobutenylarenes
Hz), 6.54 (s, 1H), 1.89 (s, 3H). 3g: 7.52 (s, 1H), 7.44-7.51 (m,
3H), 6.56 (s, 1H), 1.89 (s, 3H). 3h : 7.67 (d, 1H, J ) 7.8 Hz),
7.51 (t, 1H, J ) 7.5 Hz), 7.35 (t, 1H, J ) 7.5 Hz), 7.32 (d, 1H,
J ) 7.8 Hz), 6. 71 (s, 1H), 1.73 (s, 3H), 1.66 (br s, 1H). 3i: 7.23
(dd, 2H, J HH ) 8.5 Hz, J HF ) 5.7 Hz), 7.02 (dd, 2H, J HH ) 8.5
Hz, J HF ) 8.5 Hz), 6.48 (s, 1H), 1.86 (s, 3H).
98%): 1H NMR 7.20 (dd, 2H, J HH ) 8.5 Hz, J HF ) 5.9 Hz),
7.03 (dd, 2H, J HH ) 8.5 Hz, J HF ) 8.5 Hz), 6.26 (s, 1H), 1.86
(s, 3H); 13C NMR 161.06 (d, J CF ) 243 Hz), 135.25, 134.67 (d,
J CF ) 3.3 Hz), 130.15 (d, J CF ) 7.6 Hz), 124.05, 114.80 (d, J CF
) 21 Hz), 25.81 (septet, J CD ) 19 Hz), 19.14; HRMS calcd for
C
10H8D3F 153.1033, found 153.1034.
The 1H NMR data of the allylic chlorides-d2 4c-i are as
follows. 4c: 7.24 (d, 2H, J ) 8.0 Hz), 7.22 (d, 2H, J ) 8.0 Hz),
6.58 (s, 1H), 2.93 (septet, 1H, J ) 7.0 Hz), 2.02 (s, 3H), 1.28
(d, 6H, J ) 7.0 Hz). 4d : 7.16-7.20 (m, 4H), 6.60 (s, 1H), 2.26
(s, 3H), 1.84 (s, 3H). 4e: 7.95 (m, 1H), 7.88 (m, 1H), 7.81 (d,
1H, J ) 8.0 Hz), 7.47-7.54 (m, 3H), 7.35 (d, 1H, J ) 8.0 Hz),
7.06 (s, 1H), 1.87 (s, 3H). 4f: 7.59 (d, 2H, J ) 8.0 Hz), 7.37 (d,
2H, J ) 8.2 Hz), 6.61 (s, 1H), 1.98 (s, 3H). 4g: 7.54 (s, 1H),
7.44-7.52 (m, 3H), 6.62 (s, 1H), 1.99 (s, 3H). 4h : 7.68 (d, 1H,
J ) 7.8 Hz), 7.53 (t, 1H, J ) 7.5 Hz), 7.38 (t, 1H, J ) 7.5 Hz),
7.32 (d, 1H, J ) 7.8 Hz), 6.78 (s, 1H), 1.82 (s, 3H). 4i: 7.25
(dd, 2H, J HH ) 8.5 Hz, J HF ) 5.7 Hz), 7.03 (dd, 2H, J HH ) 8.5
Hz, J HF ) 8.5 Hz), 6.54 (s, 1H), 1.97 (s, 3H).
In tr a zeolite P h otooxygen a tion . Preparation of thionin-
supported zeolite Na-Y and the intrazeolite photooxygenation
1
procedures are described in ref 2c. The H NMR spectroscopic
data of the ene allylic hydroperoxides, formed by the intrazeo-
lite photooxygenation of the perprotio isobutenylarenes 5a -i
(d0), are the following. Ene product from 5a -d0: 7.95 (s, 1H,
OOH), 7.30-7.38 (m, 5H), 5.38 (s, 1H), 5.13 (br s, 1H), 5.08
(br s, 1H), 1.69 (s, 3H). Ene product from 5b-d0: 7.98 (s, 1H,
OOH), 7. 25 (d, 2H, J ) 7.9 Hz), 7.18 (d, 2H, J ) 7.9 Hz), 5.35
(s, 1H), 5.13 (br s, 1H), 5.07 (br s, 1H), 2.36 (s, 3H), 1.70 (s,
3H). Ene product from 5c-d0: 7.97 (s, 1H, OOH), 7.28 (d, 2H,
J ) 8.0 Hz), 7.23 (d, 2H, J ) 8.0 Hz), 5.36 (s, 1H), 5.14 (br s,
1H), 5.08 (br s, 1H), 2.92 (heptet, 1H, J ) 7.0 Hz), 1.71 (s,
3H), 1.26 (d, 6H, J ) 7.0 Hz). Ene product from 5d -d0: 8.12
(s, 1H, OOH), 7.37 (m, 1H), 5.19-7.25 (m, 3H), 5.61 (s, 1H),
5.12 (br s, 1H), 5.06 (br s, 1H), 1.74 (s, 3H). Ene product from
5e-d0: 8.21 (s, 1H, OOH), 8.14 (d, J ) 8.3 Hz, 1H), 7.89 (d, J
) 7.8 Hz, 1H), 7.86 (d, J ) 8.3 Hz, 1H), 7.58 (d, J ) 7.1 Hz,
1H), 7.48-7.55 (m, 3H), 6.15 (s, 1H), 5.21 (br s, 2H), 1.79 (s,
3H). Ene product from 5f-d0: 8.09 (s, 1H, OOH), 7.64 (d, J )
8.1 Hz, 2H), 7.49 (d, J ) 8.1 Hz, 2H), 5.44 (s, 1H), 5.12 (br s,
1H), 5.11 (br s, 1H), 1.70 (s, 3H). Ene product from 5g-d0: 8.46
(s, 1H, OOH), 7.63 (s, 1H), 7.60 (d, 1H, J ) 7.7 Hz), 7.56 (d,
1H, J ) 7.7 Hz), 7. 52 (t, 1H, J ) 7.7 Hz), 5.44 (s, 1H), 5.14 (br
s, 1H), 5.13 (br s, 1H), 1.71 (s, 3H). Ene product from 5h -d0:
8.13 (s, 1H, OOH), 7.68-7.73 (m, 2H), 7.62 (t, 1H, J ) 7.6
Hz), 7.48 (t, 1H, J ) 7.5 Hz), 5.82 (s, 1H), 5.12 (br s, 1H), 4.95
(br s, 1H), 1.79 (s, 3H). Ene product from 5i-d0: 8.05 (s, 1H,
OOH), 7.33 (dd, J H-H ) 8.0 Hz, J H-F ) 5.5 Hz, 2H), 7.06 (dd,
J H-H ) 8.0 Hz, J H-F ) 8.0 Hz, 2H), 5.36 (s, 1H), 5.13 (br s,
1H), 5.10 (br s, 1H), 1.69 (s, 3H). Ene product from 5j-d0: 7.99
(s, 1H, OOH), 7.29 (d, J ) 8.5 Hz, 2H), 6.90 (d, J ) 8.5 Hz,
2H), 5.33 (s, 1H), 5.14 (br s, 1H), 5.08 (br s, 1H), 3.81 (s, 3H),
1.70 (s, 3H).
The spectroscopic data of the deuterated alkenes 5b-i are
as follows. 5b (isomeric purity 98%): 1H NMR 7.18 (br s, 4H),
6.30 (s, 1H), 2.40 (s, 3H), 1.92 (s, 3H); 13C NMR 135.79, 135.28,
134.60, 128.71, 128.60, 124.96, 25.97 (septet, J CD ) 19 Hz),
21.08, 19.29; MS m/z ) 149 (100, m/z ) 149); HRMS calcd for
C
11H11D3 149.1283, found 149.1281. 5c (isomeric purity 95%):
1H NMR 7.19 (d, 2H, J ) 8.0 Hz), 7.17 (d, 2H, J ) 8.0 Hz),
6.25 (s, 1H), 2.90 (septet, 1H, J ) 7.0 Hz), 1.87 (s, 3H), 1.26
(d, 6H, J ) 7.0 Hz); 13C NMR: 128.75, 128.65, 126.28, 126.04,
125.01, 33.76, 24.95 (septet, J CD ) 19 Hz), 24.05, 19.34; MS
m/z ) 177 (100, m/z ) 134). 5d (isomeric purity 99%): 1H NMR
7.13-7.18 (m, 4H), 6.23 (s, 1H), 2.25 (s, 3H), 1.71 (s, 3H); 13
C
NMR 137.88, 136.28, 134.84, 129.60, 129.40, 126.20, 125.22,
124.14, 25.18 (septet, J CD ) 19 Hz), 19.86, 19.12; MS m/z )
149 (100, m/z ) 149); HRMS calcd for C11H11D3 149.1283,
found 149.1281. 5e (isomeric purity 96%): 1H NMR 8.01 (d,
1H, J ) 5.9 Hz), 7.86 (d, 1H, J ) 5.9 Hz), 7.56 (d, 1H, J ) 8.2
Hz), 7.45-7.50 (m, 3H), 7.32 (d, 1H, J ) 8.2 Hz), 6.67 (s, 1H),
1.73 (s, 3H); 13C NMR 136.77, 135.98, 133.55, 132.18, 128.27,
126.67, 126.61, 125.54, 125.29, 125.22, 122.95, 25.26 (septet,
J CD ) 19 Hz), 19.50; MS m/z ) 185 (100, m/z ) 167); HRMS
calcd for C14H11D3 185.1283, found 185.1280. 5f (isomeric
purity 93%): 1H NMR 7.56 (d, 2H, J ) 8.2 Hz), 7.32 (d, 2H, J
) 8.2 Hz), 6.29 (s, 1H), 1.88 (s, 3H); 13C NMR 142.30, 137.84,
128.88, 127.76 (q, J CF ) 31.9 Hz), 124.94 (q, J CF ) 3.5 Hz),
124.40 (q, J CF ) 270 Hz), 124.08, 26.03 (septet, J CD ) 19 Hz),
19.34; MS m/z ) 203 (100, m/z ) 203); HRMS calcd for
Ack n ow led gm en t. This work was supported in part
by the Greek Secretariat of Research and Technology.
We thank Ms. Mariza Alberti for providing three of the
deuterium-labeled alkenylarenes used in this study and
Professor M. Orfanopoulos for a prepublication copy of
their relevant work. We also thank Professor Waldemar
Adam and Dr. Oliver Krebs (University of Wu¨rzburg,
Germany) for taking some HRMS spectra.
C
11H8D3F3 203.1001, found 203.1000. 5g (isomeric purity
98%): 1H NMR 7.39-7.48 (m, 4H), 6.29 (s, 1H), 1.87 (s, 3H);
13C NMR 139.39, 137.34, 131.93, 130.42 (q, J CF ) 31.6 Hz),
128.41, 125.38, (q, J CF ) 3.2 Hz), 124.32 (q, J CF ) 271 Hz),
123.92, 122.44 (q, J CF ) 3.6 Hz), 25.88 (septet, J CD ) 19 Hz),
19.22; MS m/z ) 203 (100, m/z ) 203). 5h (isomeric purity
97%): 1H NMR 7.65 (d, 1H, J ) 7.8 Hz), 7.49 (t, 1H, J ) 7.5
Hz), 7.32 (t, 1H, J ) 7.5 Hz), 7.29 (d, 1H, J ) 7.8 Hz), 6.43 (s,
1H), 1.71 (s, 3H); 13C NMR 137.71, 137.21, 131.53, 131.13,
128.50 (q, J CF ) 29.1 Hz), 126.09, 125.56, (q, J CF ) 5.4 Hz),
124.37 (q, J CF ) 272 Hz), 122.76, 25.17 (septet, J CD ) 19 Hz),
19.19; MS m/z ) 203 (100, m/z ) 203); HRMS calcd for
Su p p or tin g In for m a tion Ava ila ble: Fifteen 1H NMR
spectra of the labeled alkenylarenes and their intrazeolite
photooxygenation reactions. Five calculated minima structures
of Na+ interaction to arenes 5f, 5i, and 5j at the B3LYP/6-
31G* level of theory. This material is available free of charge
via the Internet at http://pubs.acs.org.
C
11H8D3F3 203.1001, found 203.0999. 5i (isomeric purity
J O020599G
J . Org. Chem, Vol. 68, No. 7, 2003 2843