[2.2]-para-Cyclophane-4-carbaldehyde as building-block for chiral ligands: Part II: Epoxidation of alkenes catalyzed by the Mn(III)-complex of an atropoisomerically pure (α, β, α, β)-tetraarylporphyrin

Article abstract of DOI:10.1016/S1381-1169(98)00011-9

The synthesis of the Mn(III)-complex of the new enantiopure, atropoisomerically pure chiral porphyrin (α, β, α, β)-1 is described. The compound was used as the catalyst in the epoxidation of unfunctionalized olefins using aqueous NaOCl, 30%-H₂O₂ or PhIO as oxygen donors. Up to 780 overall turnovers were obtained in the presence of NaOCl and PhIO, whereas with 30%-H₂O₂ only catalase activity was observed. Contrary to expectations based on previous results [S. Banfi, A. Manfredi, F. Montanari, G. Pozzi, S. Quici, I. Mol. Catal., 113 (1996) 77], only racemic epoxides were obtained.

Full text of DOI:10.1016/S1381-1169(98)00011-9

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Journal of Molecular Catalysis A: Chemical 136 1998 13–22
w x
2.2 -para-Cyclophane-4-carbaldehyde as building-block for
chiral ligands
Part II: Epoxidation of alkenes catalyzed by the
ž /
Mn III -complex of an atropoisomerically pure
ž
/
a,b,a,b -tetraarylporphyrin
)
Minze T. Rispens, Amedea Manfredi, Gianluca Pozzi, Stefano Banfi, Silvio Quici
Centro CNR and Dipartimento di Chimica Organica e Industriale dell’UniÕersita, Via C. Golgi 19, 20133 Milano, Italy
`
Received 27 October 1997; accepted 22 December 1997
Abstract
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.
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The synthesis of the Mn III -complex of the new enantiopure, atropoisomerically pure chiral porphyrin a,b,a,b -1 is
described. The compound was used as the catalyst in the epoxidation of unfunctionalized olefins using aqueous NaOCl,
30%-H2O2 or PhIO as oxygen donors. Up to 780 overall turnovers were obtained in the presence of NaOCl and PhIO,
w
whereas with 30%-H2O2 only catalase activity was observed. Contrary to expectations based on previous results S. Banfi,
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.
x
A. Manfredi, F. Montanari, G. Pozzi, S. Quici, J. Mol. Catal., 113 1996 77 , only racemic epoxides were obtained. q 1998
Elsevier Science B.V. All rights reserved.
Keywords: Chiral catalyst; Oxidation catalyst; Manganese; Porphyrin; Epoxidation
1. Introduction
is enantioselective epoxidation of unfunctional-
w
x
ized alkenes by the use of chiral catalysts 7–9 .
Since high turnover numbers can be achieved
by using Mn-porphyrins as epoxidation catalysts
Haems are used in nature in combination
with proteins to perform a wide variety of tasks,
including oxygen binding and transport, energy
transfer, catalysis and electron transfer 1–3 .
The development of models for these enzymes
and the design of new catalysts to achieve selec-
tive oxygenation are important goals in syn-
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x
10–13 , manganese complexes of some chiral
porphyrins have been synthesized and tested for
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this purpose 14 . The stability and catalytic
activity of Mn-tetraarylporphyrins is greatly im-
proved by the introduction of chlorine atoms at
the ortho-positions of the meso-aryl groups
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thetic chemistry 4–6 . Particularly challenging
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10–13 . This holds also for chiral complexes,
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as independently shown by us 15 and Vilain et
)
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al. 16,17 . They reported the synthesis of robust
Corresponding author.
1381-1169r98r$ - see front matter q 1998 Elsevier Science B.V. All rights reserved.
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PII: S1381-1169 98 00011-9

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14
M.T. Rispens et al.rJournal of Molecular Catalysis A: Chemical 136 1998 13–22
X
X
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..
Fig. 1. Tetra- 2 -chloro-5 - para- S -cyclophanemethoxyphenyl porphyrin 1, paracyclophane porphyrin 2 and the statistical distribution of
the possible atropoisomers formed.
w
x
glycoconjugated porphyrins, in which one of the
chlorine atoms is replaced by an ether linked
sugar. The manganese complexes of these por-
phyrins catalyze the epoxidation of alkenes in
the presence of H2O2 with enantioselectivity up
to 23%. The presence of chlorine atoms is
crucial, since their absence resulted in rapid
decomposition of similar manganese porphyrins
2.2 -para-cyclophane-4-carbaldehyde could be
a good building-block for the synthesis of new
chiral porphyrins. The separation of the possible
atropoisomers and the catalytic activity in the
presence of oxygen donors other than NaOCl,
are readdressed in the present work by the
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.
synthesis of porphyrin 1 Fig. 1 . It can be
envisaged that the bulky groups in the meso-
position of this ligand might enhance separation
as well as efficiency and enantioselectivity in
epoxidation. Our attention was focused on the
a,b,a,b atropoisomer of porphyrin 1, since it
features two topologically identical faces char-
acterized by the presence of two chiral cyclo-
phanyl moieties.
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x
when H2O2 was used as the oxidant 16,17 .
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x
Compounds derived from 2.2 -cyclophane are
thought to be very stable to the action of light,
oxidation, acids, bases and relatively high tem-
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x
peratures 18 . We developed an efficient method
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for the resolution of racemic 2.2 -para-
cyclophane-4-carbaldehyde and with the pure
enantiomers in hand, chiral porphyrin 2 was
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. w x
synthesized Fig. 1 19 . Despite the inability in
the separation of the atropoisomers formed,
turnovers up to 700 and enantioselectivities in
the range of 22–31% were obtained when
2. Results and discussion
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)
2.1. Synthesis of catalyst a,b,a,b -Mn-1
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.
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.
Mn III complex of porphyrin 2 Mn-2 was
used in the epoxidation of unfunctionalized
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x
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.
alkenes with aqueous NaOCl 19 . These en-
couraging results suggested that enantiopure
Porphyrin a,b,a,b -1 was assembled from
atropoisomerically pure 5a,10b,15a,20b-

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M.T. Rispens et al.rJournal of Molecular Catalysis A: Chemical 136 1998 13–22
15
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.
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.
Scheme 1. Synthesis of atropoisomerically pure porphyrin a,b,a,b -1. a. K2CO3, DMF, RT, 100% .
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.
tetrakis 2-chloro-6-hydroxyphenyl porphyrin,
porphyrin synthesis the first eluted compound
might be absent. Since steric hindrance andror
electronic interaction might diminish the amount
Ž
.
Ž .
.
a,b,a,b -3, and enantiopure S -cyclophane
methyl bromide S -4 Scheme 1 .
The synthesis of bromide S -4 started from
homochiral S - 2.2 -para-cyclophane-4-carbal-
Ž .
Ž
Ž .
Ž
of the a,a,a,a atropoisomer see for instance
Ž .
w
x
the synthesis of the aforementioned glycoconju-
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x
w
x.
dehyde 19 . Reduction using LAH yielded al-
gated porphyrins 16,17 , the first eluted com-
Ž .
Ž
.
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.
cohol S -5 96% yield , which was converted
pound was identified as a,a,a,a -7. The other
1
Ž .
into the desired bromide S -4 in 81% yield by
reaction with PBr3 Scheme 2 .
Atropoisomerically pure a,b,a,b -3 was
synthesized following the pathway reported in
Scheme 3. Pyrrole was condensed with 2-
chloro-6-methoxybenzaldehyde 6 see experi-
mental part according to modified Lindsey’s
procedure 20 . 5,10,15,20-Tetrakis 2-chloro-6-
methoxyphenyl porphyrin 7 was obtained in
43% yield as a mixture of four atropoisomers.
Condensation of pyrrole with aromatic aldehy-
des bearing two different substituents in 2,6
positions is expected to produce a statistical
mixture of four atropoisomeric porphyrins in the
ratio shown in Fig. 1. Separation was enforced
by column chromatography on silica-gel and the
relative amount of the atropoisomers isolated, in
the order of elution, was 6.6%, 16.5%, 66.8%
and 10.1%. Depending on the batch of the
atropoisomers were identified by their H-NMR
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.
spectra as well as the relative amount. Accord-
ing to symmetry considerations, the pattern of
the b-pyrrolic protons in the different atropoiso-
mers was expected to be: a,a,a,a: singlet;
a,b,a,b: singlet; a,a,a,b: four doublets and
a,a,b,b: double singlet. The third eluted com-
pound showed a double singlet for the b-pyr-
rolic protons in the 1H-NMR. However, the
methoxy protons gave three singlets with a ratio
2:1:1 as expected for the a,a,a,b, atropoiso-
mer, whereas for the a,a,b,b atropoisomer a
singlet was expected. Moreover, the amount
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.
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.
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x
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.
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.
formed made up for the bulk 66.8% of the
total yield. On basis of these considerations the
compound was identified as the a,a,a,b at-
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.
ropoisomer 50% expected yield, see Fig. 1 .
Both the second and fourth eluted compounds
showed singlets for the b-pyrrolic protons so
Ž .
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.
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.
Scheme 2. Synthesis of S -4: a. LAH, Et2O, 100% ; b. PBr3, Toluene, 81% .

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16
M.T. Rispens et al.rJournal of Molecular Catalysis A: Chemical 136 1998 13–22
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.
.
.
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.
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.
Scheme 3. Synthesis of complex a,b,a,b -Mn-1: a. i pyrrole, BF3OEt2 , CH2Cl2 , ii DDQ, 43% , 4 atropoisomers ; b. column
Ž .
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.
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.
chromatography; c. BBr3, 90% ; d. Mn OAc 2 P4H2O, DMF, D, 54%; e. S -4, K2CO3, DMF, 100% .
we were not able to identify the remaining two
atropisomers at this stage. The two compounds
were separately subjected to demethylation us-
ing BBr3 giving the corresponding 5,10,15,20-
Mass spectrometry of the reaction mixture
q
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.
FAB indicated partial cleavage of the ben-
zylic cyclophanyl groups. Therefore we decided
to interconvert the introduction of the metal and
the functionalization with the homochiral cyclo-
phanyl moieties. The manganese complex of the
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.
tetrakis 2-chloro-6-hydroxyphenyl porphyrins 3
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.
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.
a,a,b,b -3 and a,b,a,b -3 in 65–70%
Ž .
Ž
.
yield. Subsequent reaction with bromide S -4
hydroxy porphyrin a,b,a,b -3, obtained as
yielded both atropoisomeric porphyrins
described above, was thus treated with cyclo-
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.
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.
Ž .
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.
a,a,b,b -1 and a,b,a,b -1 in quantitative
phanyl bromide S -4 affording a,b,a,b -
Mn-1 in quantitative yield. The nature of the
1
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yield. On basis of the H-NMR spectra double
singlet for the b-pyrrolic protons the porphyrin
.
Ž .
reaction product single spot by TLC was con-
q
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.
.
derived from the second eluted atropoisomer
firmed by mass spectrometry FAB
Ž
.
could be assigned as a,b,a,b -1, the atropoi-
somer with a higher symmetry degree. In fact,
the other compound showed a higher number of
signals in the pyrrolic region pointing to a lower
symmetry degree with respect to the former
atropoisomer, hence it could be identified as
(
)
2.2. Catalytic actiÕity of a,b,a,b -Mn-1 in the
epoxidation of alkenes
The title compound was tested in the epoxi-
dation of unfunctionalized olefins, in the pres-
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.
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.
a,a,b,b -1.
ence of an axial ligand 4-tert-butylpyridine, L ,
using styrene, 4-bromostyrene, dihydronaphtha-
lene and 1-methylcyclohexene as model sub-
Unfortunately introduction of manganese in
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.
a,b,a,b -1 by heating under reflux man-
Ž .
Ž .
ganese II acetate and the porphyrin overnight
in DMF 21 resulted in four products as deter-
mined by thin layer chromatography TLC .
strates S . Aqueous sodium hypochlorite
NaOCl , 30%-hydrogen peroxide 30%-H2O2
Ž .
and iodosylbenzene PhIO were employed as
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x
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.
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.
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.

(
)
M.T. Rispens et al.rJournal of Molecular Catalysis A: Chemical 136 1998 13–22
17
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.
primary oxidants OD , always in excess with
respect to the substrate. Reactions were carried
out at 08C in the case of NaOCl and 30%-H2O2,
and at room temperature with solid PhIO. The
pH of the aqueous solutions of NaOCl and
30%-H2O2 was adjusted at 10.0 and 4.5 respec-
tively, according to a procedure previously re-
enantiomeric excesses reported in the literature
were observed using PhIO, epoxidation of
styrene with this mild oxidant was also carried
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.
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.
out entry 9 . Although a,b,a,b -Mn-1 was
an effective catalyst in the presence of PhIO,
Ž
.
even in this case no enantioselectivity -5%
was observed.
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x
Ž
.
ported by us 22 . The outcome of the reactions
was followed by gas chromatography and re-
sults are summarized in Table 1. As already
The catalytic efficiency of a,b,a,b -Mn-1
was in the same range as reported for Mn-2.
The stability of the former catalyst was lower,
despite the presence of four ortho-chlorine
atoms: in the experiment with NaOCl and dihy-
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x Ž
found in the case of Mn-2 19 , Table 1, entries
. Ž
.
10–12 a,b,a,b -Mn-1 gave the best results
when used in association with NaOCl. Epoxida-
tion of styrene, 4-bromostyrene, dihydronaph-
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.
dronaphthalene, only 20% of a,b,a,b -Mn-1
remained after 1 h, as evaluated by UV–Vis.
With 30%-H 2O2 the ineffectiveness of
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.
thalene and 1-methylcyclohexene entries 1–4
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.
resulted in turnover numbers up to 780, with
high conversion of the substrate and selectivity
from moderate to good. Rather surprisingly, the
best results were obtained with 1-methyl-
cyclohexene which is the most hindered sub-
strate. In the presence of 30%-H2O2 the same
alkenes gave the corresponding epoxides in very
low yields entries 5–8 . In all these experi-
ments racemic epoxides were obtained, as shown
by gas chromatographic analysis of the reaction
mixture using a chiral column. Since the highest
a,b,a,b -Mn-1 as epoxidation catalyst was
due both to instability and to catalase activity.
In a control experiment, 30%-H2O2 pHs5,
0.2 ml was shaken with a solution of
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.
y
4
Ž
.
Ž
a,b,a,b -Mn-1 5=10
M in CH2Cl2, 2
.
ml . The evolvement of gas was evident and
after 1 h iodometric titration of the aqueous
layer indicated that only 50% of the initial
amount of H2O2 was still present.
The absence of enantioselectivity in the reac-
tion was totally unexpected. Beforehand a
Ž
.
Table 1
a
Ž
.
Epoxidation of unactivated olefins using complexes a,b,a,b -Mn-1 and Mn-2
Conversionb
%
Ž .
Turnoverc
Selectivityd
e.e. %
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.
Entry
Catalyst
Olefin
Oxidant
Ž
Ž
Ž
Ž
Ž
Ž
Ž
Ž
Ž
.
1
2
3
4
5
6
7
8
a,b,a,b -Mn-1
1-methylcyclohexene
styrene
4-Br-styrene
dihydronaphthalene
1-methylcyclohexene
styrene
4-Br-styrene
dihydronaphthalene
styrene
dihydronaphthalene
2X-methyl styrene
styrene
NaOCl
NaOCl
NaOCl
NaOCl
H2O2
H2O2
H2O2
H2O2
87
56
100
81
-5
-5
-5
-5
54
780
360
370
420
-5
-5
-5
-5
290
730
165
325
90
64
37
53
n.r.
n.r.
n.r.
n.r.
52
-5
-5
-5
-5
-5
-5
-5
-5
-5
22
.
a,b,a,b -Mn-1
.
a,b,a,b -Mn-1
.
a,b,a,b -Mn-1
.
a,b,a,b -Mn-1
.
a,b,a,b -Mn-1
.
a,b,a,b -Mn-1
.
a,b,a,b -Mn-1
9
a,b,a,b -Mn-1
PhIOe
NaOCl
NaOCl
NaOCl
.
10
11f
12f
Mn-2
Mn-2
Mn-2
95
65
95
77
51
68
31
26
a Molar ratios: porphyrinrsubstraterligandroxidantsPrSrLrOs1r1000r10r1500; Ts08C.
bConversion based on amount of olefin consumed.
c Turnover: amount of epoxideramount of catalyst.
dSelectivity: amount of epoxideramount of olefin consumed, n.r.snot relevant.
eTs258C.
f Molar ratios: PrSrLrOs1r500r10r1500.

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18
M.T. Rispens et al.rJournal of Molecular Catalysis A: Chemical 136 1998 13–22
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Scheme 4. Cation formation and subsequent polymerisation 23 .
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.
CPK-model of a,b,a,b -Mn-1 indicated that
the chiral cyclophanyl moieties would be lo-
cated in the vicinity of the metal centre, al-
though the –OCH2- linker allows for a certain
degree of conformational freedom of the chiral
groups. Moreover, when an atropoisomerical
mixture of catalyst Mn-2 in combination with
NaOCl as oxidant was used, enantioselectivities
drocarbons such as norbornene and tetrahydron-
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aphtalene 24 .
3. Conclusions
The new homochiral, atropoisomerically pure
Ž
.
manganese complex a,b,a,b -Mn-1 has been
synthesized and fully characterized. It has been
demonstrated that the cyclophane–methylene
moiety has a reactivity that diverges from what
was expected, leading to a lower stability of the
porphyrin derivative. The catalytic activity of
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.
up to 31% were observed entries 10–12 . The
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.
source of instability in a,b,a,b -Mn-1 might
not be due to the presence of the cyclophanyl
group only: it was tentatively ascribed to the
combined presence of the –OCH2- linker and
the bulky and electronrich chiral cyclophane.
Indeed, attempts to transform the hydroxyl group
of alcohol S -5 into a better leaving group by
reaction with sulphonyl chlorides regularly
failed. Upon evaporation during workup the so-
lution turned deep blue, and H-NMR indicated
the formation of polymeric compounds. Appar-
ently the cation was formed, followed by poly-
merization Scheme 4 23 . Our hypothesis was
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.
a,b,a,b -Mn-1 has been established in the
epoxidation of unactivated carbon–carbon dou-
ble bonds using NaOCl or PhIO as oxidants.
Unfortunately no significant enantioselectivity
in the epoxidation was achieved. The easy de-
composition of the cyclophane tethered to the
porphyrin by a methyleneoxy group precludes
an efficient transfer of the chiral information in
the oxygen transfer from the metal to the alkene.
Ž .
1
Ž
. w x
Ž .
supported by a control reaction. Alcohol S -5
was treated with dimethylsulphate to give the
Ž .
corresponding methyl ether S -8 which was
4. Experimental section
subsequently treated with aqueous NaOCl under
the standard epoxidation conditions, using Mn-
4.1. General remarks
Ž
.
tetrakis 2,6-dichlorophenyl porphyrin as cata-
lyst. After 5 h at 08C, the organic phase did not
contain any trace of methyl ether S -8, and a
mixture of several unknown products was de-
tected by TLC. It should be noted that under the
reaction conditions used here, metal-porphyrins
only catalyze the hydroxylation of reactive hy-
1H-NMR spectra were recorded on a Bruker
AC-300 spectrometer at 300 MHz. CDCl3 was
used as a solvent unless stated otherwise. Chem-
ical shifts are determined relative to the solvent
and converted to the TMS scale. Coupling con-
stants, J, are denoted in Hertz. 13C-NMR were
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)
M.T. Rispens et al.rJournal of Molecular Catalysis A: Chemical 136 1998 13–22
19
recorded on a Varian XL-300 spectrometer at
75.43 MHz. Chemical shifts are determined rel-
151.11, 136.61, 134.59, 123.09, 122.29, 110.29,
56.24.
ative to the solvent and converted to the TMS
q
Ž
.
(
4.2.2. 5,10,15,20-tetrakis 2-chloro-6-meth-
scale. MS FAB were recorded on an Analyt-
ical VG 7070 EQ spectrometer. UV–VIS spec-
tra were recorded on a Perkin Elmer Lambda 6
spectrophotometer using CH2Cl2 as solvent,
)
( )
oxyphenyl -porphyrin 7
Nitrogen was bubbled through a solution of
Ž
2-chloro-6-methoxybenzaldehyde 6 3.41 g, 20.0
6
concentration of the solutions being 2.0=10y
.
Ž
.
mmol and pyrrole 1.34 g, 20.0 mmol in
CH2Cl2 2000 ml for 10 min. BF3.OEt2
drops was added. The mixture was stirred
Ž
.
Ž
M. All reagents and solvents were purified,
dried, and stored under nitrogen when neces-
sary, using standard procedures. Chromatogra-
phy was performed using Merck silica gel 60
3
.
shielded from light until absence of starting
Ž
aldehyde was detected by TLC silica gel;
Ž
.
.
70–230 mesh . Dichloromethane for porphyrin
CH2Cl2 . Subsequently 2,3-dichloro-5,6-di-
cyano-1,4-benzoquinone DDQ, 3.42 g, 15.0
mmol was added and the solution stirred for 1
Ž
Ž
synthesis was obtained from Baker Baker Ana-
.
lyzed, stabilized with amylene, and distilled
.
from K2CO3 prior to use . For epoxidation
h. Evaporation of the solvent in vacuo and
Ž
Ž
reactions, GC analyses internal standard
column chromatography silica gel; CH2Cl2 and
.
.
method were performed on Hewlett-Packard
subsequently silica gel; EtOAc:pet. ethers1:1
yielded pure 5,10,15,20-tetrakis 2-chloro-6-
methoxyphenyl -porphyrin 7 1.86 g, 43% as
Ž
5890 gas chromatograph equipped with a chiral
Ž
.
Ž . Ž
.
column J&W Scientific Cyclodex-B, 30 m=
.
0.25 mm i.d., 0.25 mm film . The internal stan-
dards used were: PhCl methylcyclohexene , n-
a mixture of atropoisomers. Repeated column
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.
Ž
chromatography silica gel; CH2Cl2:pet. ethers
Ž
.
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.
C10H22 styrene and n-C14H30 styrene, 4-Br-
3:2 yielded the pure atropoisomers.
.
styrene and dihydronaphthalene . Aqueous
Ž
.
(
NaOCl about 13% was obtained from Fluka
and 30%-H2O2 was obtained from Aldrich. Both
oxidants were analyzed by titration following
4.2.2.1. 5a,10a,15a,20a-tetrakis 2-chloro-6-
)
[(
) ]
methoxyphenyl porphyrin a,a,a,a -7 . Yield:
1
Ž
.
Ž
Ž
112.9 mg 2.6% ; H-NMR: d 8.71–8.65 m,
8H , 7.75–7.64 m, 4H , 7.47–7.41 m, 4H ,
w
x
.
.
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.
literature procedures 25,26 . NaOCl was diluted
with distilled H2O before use to give 0.5 M
solution. Iodosylbenzene was synthesized ac-
Ž
.
Ž
.
Ž
7.21–7.18 m, 4H , 3.48 s, 12H , y2.56 br s,
2H ; 13C-NMR: d 155.69, 141.22, 132.84,
.
w
x
cording to a literature procedure 27 .
125.01, 119.57, 116.14, 108.69, 108.39, 104.05,
Ž
.
Ž
.
50.80; UV–VIS: lmax log e s416 nm 5.39 ,
q
Ž
.
Ž
.
Ž
.
511 nm 4.13 , 587 nm 3.72 ; MS FAB :
869 M -1 , lowest-mass peak of isotope clus-
4.2. Synthesis of the catalyst
q
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.
ter.
( )
4.2.1. 2-chloro-6-methoxybenzaldehyde 6
This compound was synthesized analogously
to a literature procedure starting from 2-chloro-
(
4.2.2.2. 5a,10b,15a,20b-tetrakis 2-chloro-6-
)
[(
) ]
methoxyphenyl porphyrin a,b,a,b -7 . Yield:
282.6 mg 6.5% ; H-NMR: d 8.65 s, 8H ,
1
w
x
Ž
.
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.
6-fluorobenzaldehyde 15 . The reaction was
Ž
.
Ž
.
Ž
followed by TLC silica gel; CH2Cl2: pet. ether
7.67 dd, Js8.0, Js8.3, 4H , 7.45 d, Js8.0,
.
Ž
.
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.
and quenched when the first traces of the di
methylacetal of the aldehyde appeared. Work-
4H , 7.20 d, Js8.3, 4H , 3.48 s, 12H , y2.54
br s, 2H ; 13C-NMR: d 161.09, 138.16, 130.91,
130.29, 128.84, 121.41, 112.42, 109.39, 56.17;
Ž
.
up was the same as described previously.
1
Ž
.
Ž
Ž
.
Ž
.
.
Yield: 70%; H-NMR: d 10.49 s, 1H , 7.39 t,
UV–VIS: lmax log e s417 nm 5.53 , 512
nm 4.26 , 586 nm 3.79 ; MS FAB : 869
M -1 , lowest-mass peak of isotope cluster.
q
.
Ž
.
Ž
Ž
.
Ž
.
Ž
Js8.2, 1H , 7.03 d, Js8.2, 1H , 6.90 d,
Js8.2, 1H , 3.90 s, 3H ; 13C-NMR: d 189.19,
q
.
Ž
.
Ž
.

(
)
20
M.T. Rispens et al.rJournal of Molecular Catalysis A: Chemical 136 1998 13–22
5.20 br s, 4H , y2.67 br s, 2H ; 13C-NMR: d
(
Ž
.
Ž
.
4.2.2.3. 5a,10a,15a,20b-tetrakis 2-chloro-6-
[( ) ]
)
methoxyphenyl porphyrin a,a,a,b -7 . Yield:
1152 mg 26.4% ; H-NMR: d 8.65 s, 4H ,
151.77, 142.04, 131.92, 126.16, 125.88, 121.24,
116.17, 109.24, 105.22; UV–VIS: lmax log
1
Ž
.
Ž
.
Ž
Ž
.
Ž
.
.
Ž
.
.
Ž
.
8.64 s, 4H , 7.68 dd, Js8.1, Js8.3, 4H ,
e s416 nm 5.39 , 509 nm 4.18 , 584 nm
q
q
Ž
.
Ž
.
Ž
.
Ž
Ž
.
7.46 d, Js8.1, 4H , 7.21 d, Js8.3, 4H ,
3.76 ; MS FAB : 813 M -1 , lowest-mass
Ž
.
Ž
.
Ž
.
3.50 s, 6H , 3.49 s, 3H , 3.47 s, 3H , y2.54
peak of isotope cluster.
br s, 2H ; 13C-NMR: d 160.20, 136.84, 130.64,
130.05, 128.61, 120.97, 112.18, 110.64, 109.55,
Ž
.
(
4.2.4. 5a ,10a ,15b,20b-tetrakis 2-chloro-6-
Ž
.
Ž
.
)
[(
) ]
55.70; UV–VIS: lmax log e s417 nm 5.56 ,
hydroxyphenyl porphyrin a,a,b,b -3
q
Ž
.
Ž
.
Ž
.
512 nm 4.28 , 587 nm 3.80 ; MS FAB :
869 M -1 , lowest-mass peak of isotope clus-
The reaction was performed as described for
a ,b ,a ,b -3, starting from porphyrin
a,a,b,b -7. The column chromatography was
q
Ž
.
Ž
Ž
.
.
ter.
performed on silica gel using CH2Cl2:MeOHs
1
(
Ž
.
4.2.2.4. 5a,10a,15b,20b-tetrakis 2-chloro-6-
9:1 as eluent. Yield: 245 mg 85% ; H-NMR:
)
[(
) ]
Ž
.
Ž
.
Ž
methoxyphenyl porphyrin a,a,b,b -7 . Yield:
173.4 mg 4.0% ; H-NMR CDCl3 plus added
d 8.79 s, 8H , 7.66–7.61 m, 4H , 7.44 d,
1
Ž
.
Ž
.
Ž
.
Ž
Js7.9, 4H , 7.19 d, Js8.2, 4H , y2.81 br
s, 2H ; 13C-NMR: d 159.02, 136.58, 131.76,
.
Ž
Ž
.
Ž
.
DMSO-d6 : d 8.40 s, 8H , 7.49 dd, Js8.2,
.
.
Ž
Ž
Js8.3, 4H , 7.22 d, Js8.2, 4H , 7.04 d,
130.98, 128.72, 127.24, 119.62, 114.47, 112.97;
.
Ž
.
.
Ž
.
Ž
.
Js8.3, 4H , 3.31 s, 12H , y2.90 br s, 2H ;
UV–VIS: lmax log e s416 nm 5.38 , 511
13
q
Ž
.
Ž
.
Ž
.
Ž
.
C-NMR CDCl3 plus added DMSO-d6 : d
160.44, 136.67, 131.48, 130.68, 128.60, 128.39,
121.26, 112.56, 110.42, 56.20; UV–VIS: lmax
nm 4.21 , 585 nm 3.84 ; MS FAB :813
M -1 , lowest-mass peak of isotope cluster.
q
Ž
.
Ž
.
Ž
.
Ž
.
[
(
log e s417 nm 5.54 , 512 nm 4.23 , 587
4.2.5. 5a,10b,15a,20b-tetrakis 2-chloro-6-
q
q
21
22
23
24
Ž
.
Ž
.
Ž
.
)
]
nm 3.70 ; MS FAB : 869 M -1 , lowest-
mass peak of isotope cluster.
hydroxyphenyl porphinato-N ,N ,N ,N
[(
)
]
manganese chloride a,b,a,b -Mn-3
Ž
.
Ž
A solution of a,b,a,b -3 100 mg, 122
(
.
Ž
.
4.2.3. 5a ,10b,15a ,20b-tetrakis 2-chloro-6-
mmol in DMF 25 ml was boiled under reflux.
Solid Mn OAc P4H2O 245 mg, 1.0 mmol
was added and the resulting mixture boiled
under reflux for 16 h. After removal of the
solvent in vacuo the residue was redissolved in
)
[(
) ]
Ž
.
Ž
.
hydroxyphenyl porphyrin a,b,a,b -3
A solution of a,b,a,b -7 310 mg, 355
mmol in CH2Cl2 was cooled to 08C. To this
solution was added BBr3 1.0 M in CH2Cl2, 25
ml, 25 mmol , giving an emerald green solution.
The mixture was stirred for 1 h, after which the
temperature was allowed to reach room temper-
ature and subsequently stirred for 64 h. The
reaction was quenched by adding ice. Aqueous
NaHCO3 5% was added until the solution
turned purple. The organic layer was separated
and the aqueous layer was extracted with
CH2Cl2 3=50 ml . The combined organic
phases were dried Na2SO4 . Removal of the
solvent gave a purple powder, that was purified
2
Ž
.
Ž
.
Ž
.
Ž
.
CH2Cl2 25 ml and filtered. The filtrate was
Ž
.
washed with water 3=25 ml . Drying and
removal of the solvent gave a brown powder,
which was purified by column chromatography
Ž
.
silica gel; CH2Cl2:MeOHs9:1 . Yield: 70 mg
Ž
.
Ž
.
Ž
.
Ž
.
.
66% ; UV–VIS: lmax log e s369 nm 4.07 ,
q
Ž
.
.
Ž
.
Ž
478 nm 4.33 , 576 nm 3.48 ; MS FAB :
q
Ž
867 M , lowest-mass peak of isotope cluster.
Ž
.
4 ,7
Ž
.
( ) (
[
]
4.2.6. S - tricyclo 8.2.2.2
)
hexadeca-
[( ) ]
4,6,10,12,13,15-hexaene -methyl alcohol S -5
This compound was synthesized in quantita-
tive yield following a procedure previously de-
Ž
by column chromatography silica gel;
.
Ž
.
CH2Cl2:MeOHs95:5 . Yield: 231 mg 80% ;
H-NMR: d 8.88 s, 8H , 7.70–7.65 m, 4H ,
7.46 d, Js7.9, 4H , 7.32 d, Js8.2, 4H ,
1
Ž
.
Ž
.
Ž . Ž
scribed by us, starting from S - tricyclo-
8.2.2.2 hexadeca - 4,6,10,12,13,15-hexaene -
4,7
Ž
.
Ž
.
w
x
.

(
)
M.T. Rispens et al.rJournal of Molecular Catalysis A: Chemical 136 1998 13–22
21
1
w
x
Ž
Ž .
carboxaldehyde. 19 H-NMR: d 6.59 dd, Js
til the excess of S -4 was collected, followed
.
Ž
.
.
7.8, Js1.7, 1H , 6.56–6.45 m, 4H , 6.40–6.37
by CH2Cl2:MeOHs95:5 . Yield: 139 mg
1
Ž
.
Ž
.
Ž
Ž
.
Ž
.
m, 2H , 4.53 dd, Js98.6, Js12.7, 2H ,
98% ; H-NMR: d 8.73 d, Js6.1, 8H , 7.57
Ž
.
Ž
.
Ž
.
Ž
3.44–3.35 m, 1H , 3.18–2.81 m, 7H , 1.55 br
dd, Js8.3, Js8.1, 4H . 7.41 d, Js8.1,
s, 1H ; 13C-NMR: d 140.27, 139.75, 139.55,
.
.
Ž
.
Ž
.
4H , 7.11 d, Js8.3, 4H , 6.13–6.00 m, 16H ,
Ž
.
Ž
.
.
Ž
Ž
139.27, 137.48, 135.00, 133.31, 133.25, 132.38,
132.18, 132.12, 129.07, 64.48, 35.31, 35.06,
34.42, 32.81
5.77 d, Js7.9, 4H , 5.43 s, 4H , 4.83 d,
.
.
Ž
Js13.2, 4H , 4.74 d, Js7.9, 4H , 4.58 d,
Ž
.
Js13.3, 4H , 2.58–2.17 m, 24H , 1.79–1.63
m, 8H , y2.16 br s, 2H ; 13C-NMR: d 160.93,
159.85, 139.67, 138.83, 138.34, 138.06, 137.20,
Ž
.
Ž
.
4 ,7
( ) (
[
]
4.2.7. S - tricyclo 8.2.2.2
)
hexadeca-
[( )
Ž
.
4,6,10,12,13,15-hexaene -methyl bromide S -
135.11. 134.56, 133.85, 133.69, 133.18 2= ,
132.48, 131.78, 131.71, 130.91, 130.10, 129.54,
128.06, 121.37, 113.01, 111.19, 69.36, 34.24,
33.79, 32.39, 29.70; UV–VIS: lmax log e s
419 nm 5.64 , 513 nm 4.37 , 587 nm 3.93 ;
]
4
Ž
.
To a solution of PBr3 50 mg, 183 mmol in
toluene 20 ml was added pyridine 20 mg, 250
Ž
.
Ž
Ž
.
.
Ž
.
Ž
.
.
Ž
.
mmol . The solution was cooled to y58C and a
q
q
Ž .
.
Ž
.
Ž
solution of alcohol S -5, 119 mg, 0.50 mmol
MS FAB : 1693 M -1 , lowest-mass peak of
Ž
.
in toluene 10 ml was added dropwise. The
reaction mixture was stirred for 1 h, allowed to
reach room temperature and stirred for 48 h.
The toluene was removed in vacuo. The residue
was redissolved in CH2Cl2, filtered and the
solvent removed in vacuo. Column chromatog-
isotope cluster.
(
(
4.2.9. 5a,10a,15b,20b-tetrakis 2-chloro-6- 5-
4 ,7
(( )
[
]
S -tric y c lo 8 .2 .2 .2
)
h e x a d e c a -
)
)
4,6,10,12,13,15-hexaene methoxy phenyl por-
[(
) ]
phyrin a,a,b,b -1
Ž
.
raphy silica gel; CH2Cl2:pet. ethers1:1 gave
The reaction was performed as described for
1
Ž .
Ž
.
pure S -4. Yield: 81%; H-NMR: d 6.60–6.53
m, 1H , 6.53–6.46 m, 4H , 6.42–6.33 m,
porphyrin a,b,a,b -1 starting from porphyrin
Ž
.
Ž
.
Ž
Ž
.
Ž .
a,a,b,b -3 and bromide S -4. Yield: 130
1
.
Ž
.
Ž
.
Ž
.
2H , 4.36 dd, Js88.1, Js10.2, 2H , 3.50–
mg 94% ; H-NMR: d 8.92–8.54 m, 8H ,
Ž
.
Ž
.
Ž
.
Ž
.
3.41 m, 1H , 3.30–3.15 m, 1H , 3.13–2.87
7.80–7.10 m, 12H , 6.60–5.82 m, 24H ,
5.65–5.42 m, 4H , 5.42–5.28 m, 4H , 4.64–
m, 6H ; 13C-NMR: d 140.40, 139.55, 139.20,
Ž
.
Ž
.
Ž
.
Ž
.
Ž
.
Ž
138.17, 136.35, 135.58, 134.87, 133.46, 133.22,
132.18, 129.60, 35.26, 34.87, 34.48, 33.31,
32.98.
4.00 m, 12H , 3.14–1.39 m, 48H , y2.81 br
.
Ž
.
Ž
.
s, 2H ; UV–VIS: lmax log e s417 4.98 ,
q
q
Ž
.
Ž
.
Ž
.
Ž
512 3.77 , 590 3.20 ; MS FAB : 1693 M -
.
1 , lowest-mass peak of isotope cluster.
(
(
4.2.8. 5a,10b,15a,20b-tetrakis 2-chloro-6- 5-
4 ,7
(( )
[
]
{
(
S -tric y c lo 8 .2 .2 .2
)
h e x a d e c a -
)
4.2.10. 5a,10b,15a,20b-tetrakis 2-chloro-6-
4,7
)
( (( )
[
]
4,6,10,12,13,15-hexaene methoxy phenyl por-
5- s -tricyclo 8.2.2.2.
)
hexadeca-4,6,10,
)
[(
) ]
)
phyrin a,b,a,b -1
12,13,15-hexaene methoxy phenyl porphinato-
N21,N 22,N 23,N 24 Manganese chloride
a,b,
Ž
.
Ž
}
[(
To a solution of a,b,a,b -3 67 mg, 82
.
Ž .
Ž
.
)
]
mmol and bromide S -4 248 mg, 822 mmol
a,b -Mn-1
Ž
.
Ž
Ž
.
Ž
in DMF 50 ml was added K2CO3 1.38 g, 10
Complex a,b,a,b -Mn 3 25.3 mg, 28
.
.
Ž .
mmol . The resulting mixture was stirred for 16
mmol was allowed to react with bromide S -4

(
)
22
M.T. Rispens et al.rJournal of Molecular Catalysis A: Chemical 136 1998 13–22
w x
3
Ž
.
D.E. Dolphin Ed. , The Porphyrins, Academic Press, New
York, 1979.
4.3. Epoxidation reactions
w x
Ž
.
4
R.A. Sheldon, J.K. Kochi Eds. , Metal-Catalyzed Oxidations
Epoxidation reactions were carried out in a
10 ml flask equipped with a Teflon-lined screw
cap and a magnetic stirrer, and the temperature
maintained at 08C with circulating ethanol. The
of Organic Compounds, Academic Press, New York, 1981.
K.A. Jørgensen, Chem. Rev. 89 1989 431.
H. Mimoun, in: G. Wilkinson, R.D. Gillard, J.A. McCleverty
Eds. , Comprehensive Coordination Chemistry, Vol. 6,
Pergamon, Oxford, 1987, p. 317.
J.P. Collman, X. Zhang, V.J. Lee, E.S. Uffelman, J.I. Brau-
man, Science 261 1993 1401.
E.N. Jacobsen, in: I. Ojima Ed. , Catalytic Asymmetric
w x
Ž
.
5
w x
6
Ž
.
y
3
w x
7
Ž .
flask was charged with: i 1 ml of a 1.0=10
Ž
.
Ž
.
Ž .
M solution of a,b,a,b -Mn-1 in CH2Cl2; ii
w x
8
Ž
.
1 ml of a 1.0 M solution of alkene in CH2Cl2,
Synthesis, VCH, New York, 1993, p. 159.
R.A. Johnson, K.B. Sharpless, in: I. Ojima Ed. , Catalytic
Asymmetric Synthesis, VCH, New York, 1993, p. 103.
w x
9
Ž
.
Ž
. Ž .
containing the internal standard 0.25 M ; iii
0.1 ml of a 0.1 M solution of tert-butylpyridine
in CH2Cl2. The solution was stirred for 10 min.
w
w
x
10 Special Issue: Recent Developments in Biomimetic Oxida-
tion Catalysis, J. Mol. Catal. 113, 1996.
Ž
x
Ž
.
Subsequently the oxidant 3 ml of aqueous
11 F. Montanari, L. Casella Eds. , Metalloporphyrins Catalyzed
Oxidations, Kluwer Academic Publishers, Dordrecht, 1994.
NaOCl 0.5 M adjusted to pHs10.0 using 0.1
M HCl, or 0.11 ml of 30%-H2O2 adjusted to
pHs5.0 using sodium benzoate, or 330 mg of
w
w
w
x
Ž
.
12 D. Mansuy, Coord. Chem. Rev. 125 1993 129.
x
Ž
.
13 B. Meunier, Chem. Rev. 92 1992 1411.
x
14 S. Vilain-Deshayes, A. Robert, P. Maillard, B. Meunier, M.
Ž
.
Momenteau, J. Mol. Catal. 113 1996 23, and references
cited therein.
.
solid PhIO was added and the reaction mixture
was stirred for 16 h at 1300"50 rpm. The
layers were separated, the organic layer filtered
over silica gel and analyzed by GC.
w
w
w
w
w
w
w
w
x
15 S. Banfi, F. Montanari, G. Pozzi, S. Quici, Gazz. Chim. Ital.
Ž
.
123 1993 617.
x
16 S. Vilain, P. Maillard, M. Momenteau, J. Chem. Soc. Chem.
Commun., 1994, p. 1697.
x
17 S. Vilain-Deshayes, P. Maillard, M. Momenteau, J. Mol. Cat.
Ž
.
113 1996 201.
x
Ž
.
18 S.M. Rosenfeld, P.M. Keeh Eds. , The Cyclophanes, Vol. 1,
Acknowledgements
Academic Press, New York, 1983, p. 2.
x
19 S. Banfi, A. Manfredi, F. Montanari, G. Pozzi, S. Quici, J.
Ž
.
Mol. Catal. 113 1996 77.
This investigation was supported by the Eu-
x
20 J.S. Lindsey, I.C. Schreiman, H.C. Hsu, P.C. Kearney, A.M.
Ž
ropean Community Human Capital and Mobil-
Ž
.
Marguerettaz, J. Org. Chem. 52 1987 827.
ity Program—Contract no ERBCHRXTC 94-
x
21 A.D. Adler, F.P. Longo, F. Kampas, J. Kim, J. Inorg. Nucl.
.
Ž
.
0492 . We wish to thank Mr. A. Girola for
Chem. 32 1970 2443.
x
Ž
.
22 S. Quici, S. Banfi, G. Pozzi, Gazz. Chim. Ital. 123 1993
recording the NMR spectra.
597.
w
w
x
Ž
.
23 D.J. Cram, L.A. Singer, J. Am. Chem. Soc. 75 1963 1075.
x
24 P.L. Anelli, S. Banfi, F. Montanari, S. Quici, J. Chem. Soc.
Chem. Commun., 1989, p. 779.
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w
x
25 A.I. Vogel, A Textbook of Quantitative Inorganic Analysis,
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w x
1
Ž
.
H. Sigel, A. Sigel Eds. , Metal Ions in Biological Systems,
Marcel Dekker, New York, 1991.
w
x
26 A.J. Martin, in: J. Mitchell Jr., I.M. Kolthoff, E.S. Proskauer,
Ž
.
A. Weissberger Eds. , Determination of Organic Peroxides
in Organic Analysis, Vol. 4, Interscience, New York, 1960,
p. 14.
w x
2
I. Bertini, H.B. Gray, S.J. Lippard, J.S. Valentine, Bioinor-
ganic Chemistry, University Science Books, Mill Valley,
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w
x
Ž
.
27 H. Saltzman, J.G. Sharefkin, Org. Synth. 5 1973 658.