Synthesis of novel planar-chiral [2.2]paracyclophane derivatives as potential ligands for asymmetric catalysis

Article abstract of DOI:10.1016/j.jorganchem.2005.10.031

The synthesis of a variety of new 4,5-disubstituted [2.2]paracyclophane derivatives has been achieved employing different cross-coupling reactions. By this methodology, a heteroatom-variation of successful catalyst ligands was achieved, giving rise to a m

Full text of DOI:10.1016/j.jorganchem.2005.10.031

Journal of Organometallic Chemistry 691 (2006) 2171–2181
www.elsevier.com/locate/jorganchem
Synthesis of novel planar-chiral [2.2]paracyclophane derivatives
as potential ligands for asymmetric catalysis
a
b
a,
*
Michael Kreis , Martin Nieger , Stefan Br a¨ se
a
Institut f u¨ r Organische Chemie, Universit a¨ t Karlsruhe (TH), Fritz-Haber-Weg 6, D-76131 Karlsruhe, Germany
Institut f u¨ r Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universit a¨ t Bonn, Gerhard-Domagk-Strasse 1, D-53121 Bonn, Germany
b
Received 17 August 2005; received in revised form 20 October 2005; accepted 20 October 2005
Available online 6 December 2005
Abstract
The synthesis of a variety of new 4,5-disubstituted [2.2]paracyclophane derivatives has been achieved employing different cross-
coupling reactions. By this methodology, a heteroatom-variation of successful catalyst ligands was achieved, giving rise to a modular
0
0
ligand system. The X-ray structure of 4-hydroxy-5-(1 -hydroxy-1 -phenylethyl)-[2.2]paracyclophane was determined to elucidate the con-
figuration. Additionally, a diastereoselective synthesis of planar- and central-chiral 4-([2.2]paracyclophanyl)ethylamine was achieved,
thus resulting in a planar- and central-chiral phenyl ethylamine analogue.
ꢀ
2005 Elsevier B.V. All rights reserved.
Keywords: [2.2]paracyclophane; Asymmetric catalysis; Cross-coupling reaction; Planar chirality
1
. Introduction
heteroatom combinations, providing potential ligands for
the asymmetric catalysis.
The element of planar chirality plays an increasingly
important role in modern Organometallic Chemistry. For
example, ligands with a planar-chiral backbone are prom-
inently used for the hydrogenation of carbon–carbon
double-bonds, for the reduction of carbonyl and imino
groups, for hydroboration, and others [1]. Especially, the
field of [2.2]paracyclophane chemistry has developed consid-
erably since these compounds first attracted the interest of
chemists in the middle of the last century [2]. Recently, there
has been notable progress, especially regarding the synthesis
of new derivatives [3] and their applications in asymmetric
catalysis [4]. In our group, we were able to employ 4,5-disub-
stituted bidentate N,O-ligands in the enantioselective orga-
nyl zinc addition to aldehydes [5], imines [6] and in the
2. Results and discussion
2.1. Variation of the substitution pattern in the 4-position
Our first target was to obtain variations of the success-
fully applied 4,5-disubstituted bidentate N,O-ligands
(Fig. 1). We surmised that by changing the phenolic
hydroxy-group to a softer amino function, we would
obtain improved ligands for the 1,4-addition to a,b-unsat-
urated aldehydes or ketones (Fig. 1).
The strategy was to apply our newly developed Hartwig–
Buchwald-amination for mono-substituted [2.2]para-
cyclophane-derivatives [8] towards 4,5-disubstituted
[2.2]paracyclophane triflates [9] or nonaflates. These had to
be synthesized starting from known phenols [10] (Table 1).
Reaction of 5-formyl-4-hydroxy[2.2]paracyclophane
1
,4-addition to a,b-unsaturated aldehydes and ketones [7].
We herein report the synthesis of a variety of new 4,5-
disubstituted [2.2]paracyclophane derivatives with different
(FHPC) with sodium hydride and trifluoromethanesulfonic
*
acid anhydride in toluene (entry 1) resulted in the desired
product in very good 91% isolated yield [11]. Under the
Corresponding author. Fax: +49 721 608 8581.
E-mail address: braese@ioc.uka.de (S. Br a¨ se).
0
022-328X/$ - see front matter ꢀ 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2005.10.031

2172
M. Kreis et al. / Journal of Organometallic Chemistry 691 (2006) 2171–2181
Table 1
Synthesis of perfluoroalkanesulfonic acid-(5-acyl-[2.2]paracyclophane-4-
yl)esters
R
R
R
O
2
equiv. Tf2O or NfF
N R
N R
O
5 equiv. base
O
OH
NR2
NR2
0
˚C RT, 24 h
R
R
OH
OX
successfully applied
N,O-ligands
N,N-ligands
N,O-ligands
R= H, Ph, Me
X = Tf or Nf
Entry
1
R
H
Base/
reagent
Solvent
Major
Product
Yield
[%]
Fig. 1. Primary target molecules.
same reaction conditions, nonafluorobutanesulfonic acid
fluoride (NfF) as reagent delivered no product (entry 2).
By changing the solvent from toluene to DME, the corre-
sponding nonaflate was isolated in excellent 95% yield
NaH/
Toluene
Toluene
DME
O
O
O
O
91
–
2
Tf O
OTf
(
entry 3). By applying these conditions (DME and sodium
NaH/
NfF
2
3
4
5
H
hydride) and using Tf O instead of NfF, no triflate was
2
obtained but the methoxy compound, 5-formyl-4-meth-
oxy[2.2]paracyclophane, was synthesized (entry 4). This
can either be explained by demethylation of monoglyme
or by deprotonation of the monoglyme and elimination
of methanolate and a subsequent nucleophilic aromatic
substitution of the initially formed triflate with the methan-
olate. A direct application of respectively optimized condi-
tions towards 5-benzoyl-4-hydroxy[2.2]paracyclophane
ONf
ONf
NaH/
NfF
H
95
84
92
NaH/
H
DME
2
Tf O
OMe
(
(
5
BHPC) resulted in the desired products in high yields
92% for the triflate and 99% for the nonaflate, entries
+ 6). Further application of these conditions to enoliz-
NaH/
Tf
Ph
Toluene
O
2
O
able 5-acetyl-4-hydroxy[2.2]paracyclophane (AHPC) did
not result in the desired products. With sodium hydride
as a strong base, the enolate was initially formed, which
was subsequently converted to the a-trifluoromethanesulf-
onic- and a-nonafluorobutanesulfonic-derivative, respec-
tively (entries 7 + 8). Applying weak amine bases like
triethylamine, H u¨ nigÕs base or pyridine resulted in no con-
version. Only the use of the amidine base DBU (1,8-diaza-
bicyclo[5.4.0]undecen-7-ene) gave trifluoromethanesulfonic
acid-(5-acetyl-[2.2]paracyclophane-4-yl)ester in 25% yield
Ph
OTf
NaH/
NfF
6
7
8
9
Ph
DME
O
99
84
79
25
Ph
ONf
OH
OH
NaH/
Me
Me
Me
Toluene
DME
O
O
O
2
Tf O
Tf
(
entry 9). To yield the corresponding imines, two
NaH/
NfF
approaches were possible: conversion of the literature
known hydroxy-imines [12] to the triflates or condensation
of the above synthesized triflates with a-chiral amines. For
the AHPC- or BHPC-derived ketimines, the former was
the method of choice (Scheme 1).
Starting from enantiomerically pure central- and planar-
chiral ketimines 1 and 3, the corresponding triflates 2 and 4
were synthesized in 49% and 41% isolated yield by the
improved protocol of Table 1 without racemisation. For
the FHPC-derived aldimines, the latter approach was supe-
rior (Scheme 2).
Nf
DBU/
Toluene
2
Tf O
OTf
The reaction proceeded in 47% isolated yield with
mol% Pd (dba) and 10 mol% racemic Binap as catalyst
5
2
3
Condensation of the racemic aldehyde triflate 5 with
enantiomerically pure (S)-phenyl ethylamine resulted in
ligand, resulting in a novel 4,5-disubstituted N,O-[2.2]para-
cyclophane derivative. Standard transformations, like the
condensation of 8 to an imine or the Hartwig–Buchwald-
reaction of the imine triflate 4 to the aniline, will give rise
to the second target class of Fig. 1, 4,5-disubstituted
N,N-[2.2]paracyclophane derivatives. The synthesis of
these derivatives is under investigation.
the diastereomeric aldimines (S ,S)-6 and (R ,S)-6 in 62%
p
p
overall yield which could be separated by column chroma-
tography. With these molecules in hand, we applied the
BHPC triflate (Table 1, entry 5, 7) exemplary in a Har-
twig–Buchwald-reaction (Scheme 3).

M. Kreis et al. / Journal of Organometallic Chemistry 691 (2006) 2171–2181
2173
[
2.2]paracyclophanes [14] and the subsequent reaction with
an halide electrophile. These can then be used as starting
materials for further variations via cross-coupling reac-
tions. To achieve this goal, 4-substituted [2.2]paracyclo-
phanes with ortho directing groups had to be synthesized
initially [15] (Scheme 4).
Both oxygen-bound derivatives 10 and 11 were prepared
in 77% and 50%, respectively, starting from litera-
ture known 4-hydroxy[2.2]paracyclophane (9). Synthesis
of nitrogen-bound [2.2]paracyclophane 13 underwent
smoothly in 68% yield using (N-methyl)-(N-4-[2.2]paracy-
clophanyl)amine and methoxycarbamoylchloride in chlo-
roform. Synthesis of the carbamic acid t-butylester with
t-butylcarbamic acid anhydride, on the other hand,
resulted in no conversion. The obtained [2.2]paracyclo-
phane derivatives were applied in a DoM [16] with a subse-
quent electrophilic substitution (see Table 2).
N
Tf O, NaH
2
N
toluene, 0 ˚C
Ph
Ph
24 h
TfO
HO
R ,S)-1
49%
(
(R ,S)-2
p
p
N
N
Tf O, DBU
2
toluene, 0 ˚C
OH
Sp,R)-3
OTf
(S ,R)-4
24 h
41%
(
p
Scheme 1. Synthesis of the [2.2]paracyclophane ketimine triflates 2 and 4.
Different combinations of electrophile and [2.2]paracyc-
lophane derivative were tested. Reaction of iodine with the
MEM-derivative gave no conversion (entry 1) whereas only
the demethylation product, 4-[2.2]paracyclophanylcarba-
mic acid methylester, was obtained as a result of the reac-
tion of the N-methylcarbamate with s-BuLi (entry 2). Only
with O-(4-[2.2]paracyclophanyl) diethylcarbamate as sub-
strate, the DoM succeeded. Where iodine as electrophile
only resulted in poor 5% conversion towards the desired
product (entry 3) and bromine resulted in no conversion
at all (entry 4), 1,2-diiodoethane was the electrophile of
choice. Here, a good conversion of 66% to the desired
N
H
2
0 mol% Bu Sn(OAc) ,
OTf
2
2
(
S)-1-phenylethylamine
O
H
(S ,S)-6
p
toluene,
reflux, 16 h
+
OTf
rac)-5
6
2%
(
N
H
TfO
4,5-disubstituted [2.2]paracyclophane-derivative was ach-
(
R ,S)-6
p
ieved (entry 5). With the product in hand, we were now
able to apply it to a palladium-catalyzed C–S-bond-forming
reaction (see Scheme 5).
Scheme 2. Synthesis of [2.2]paracyclophane aldimines triflate 6.
2
.5 equiv. benzylamine
3
5
equiv. K PO
O
3
4
mol% Pd (dba)
2
3
1
0 mol% Binap
toluene, 90 ˚C, 16 h
7%
Cl
NEt2
O
O
DMAP, toluene
O
OTf
NH
4
7
7%
OH
O
NEt2
9
10
11
7
8
NaH, MEM-Cl
DMF
Scheme 3. Hartwig–Buchwald-reaction of a 4,5-disubstituted [2.2]para-
cyclophane triflate 7.
5
0%
O
OH
O
N
O
Me
2
.2. Novel substitution patterns
9
O
One of the main problems in the synthesis of disubsti-
Cl
OMe
tuted [2.2]paracyclophanes is the lack of regioselectivity
for the second substitution reaction. For example, the elec-
trophilic bromination of 4-bromo[2.2]paracyclophane
yields four different stereoisomers [13]. Until now, a general
route for a variety of different 4,5-disubstituted [2.2]para-
cyclophanes is still elusive. Our approach incorporates
the directed ortho metallation (DoM) of mono-substituted
DMAP, CHCl3
68%
O
NH
Me
OMe
Me
1
2
13
Scheme 4. Synthesis of [2.2]paracyclophanes with ortho directing groups.

2174
M. Kreis et al. / Journal of Organometallic Chemistry 691 (2006) 2171–2181
Table 2
Directed ortho metallation
2.5 equiv. MeLi
1
) s-BuLi, TMEDA
THF, -78˚C 0 ˚C
O
O
OH
OH
toluene, 0 ˚C RT
16 h
MDG
MDG
2
) electrophile
OH
(rac)-16
61%
OH
(rac)-17
5
h, 0 ˚C
E
MDG = metal directing group
E = Br or I
Entry
MDG
Electrophile
Yield (%)
2.5 equiv. PhLi
1
2
3
4
5
a
OMEM
I
2
–
–
a
N(Me)C(O)OMe
ICH
2
CH
2
2
I
I
toluene, 0 ˚C RT
16 h
65%
OC(O)NEt
OC(O)NEt
OC(O)NEt
2
2
2
I
2
5
–
66 [17]
OH
rac)-18
OH
(rac)-19
Br
ICH
2
2
CH
(
Main product is the demethylation product.
2.5 equiv. MeLi
O
OH
toluene, 0 ˚C RT
1
6 h
The reaction of the sterically hindered O-(5-iodo-
2.2]paracyclophan-4-yl)diethyl carbamate (14) with tri-
isopropylsilanylthiole (TIPS-SH), cesium carbonate and
OH
rac)-18
OH
(rac)-20
72%, de > 99%
[
(
Scheme 6. Nucleophilic addition to AHPC (16) and BHPC (18).
Pd(PPh ) in toluene at 100 ꢁC resulted in the desired O-
3
4
(5-(4-triisopropylsilanylsulfuryl)-[2.2]paracyclophanyl)diethyl
carbamate (15) in 38% isolated yield [18]. This product is
especially noteworthy because it can be synthesized as an
enantiomerically pure compound, starting from known
enantiomerically pure 4-hydroxy-[2.2]paracyclophane.
Further investigations in this product are in progress.
Another interesting group of compounds are [2.2]para-
cyclophane derivatives with a stereogenic center in a-posi-
tion to the [2.2]paracyclophane backbone [19]. With two
substituents, these could be utilized as ligands in the asym-
metric catalysis and mono-substituted as planar- and cen-
tral-chiral phenyl ethylamine analogues. Initially, the
nucleophilic attack of methyllithium and phenyllithium to
AHPC and BHPC was tested (see Scheme 6).
formational fixation of the starting material due to hydro-
gen-bonding between the phenolic hydroxyl-group and
the carbonyl-group (Fig. 2). The nucleophilic attack of
the methyllithium is effectively blocked from one side
by the [2.2]paracyclophane-backbone [20], which leads to
the observed stereoselectivity.
Compound 19 is another interesting product. Under
weak acidic conditions like treatment with silica gel or ace-
tic acid, water is eliminated resulting in a stable mono-
dearomatized diphenylmethylenecyclohexa-2,4-dienone 21
(see Schemes 7).
The intermediary cation should be very stable due to the
sterically demanding [2.2]paracyclophane as well as its elec-
tronic properties, comparable to the trityl cation.
Both addition of methyllithium to AHPC (16) and of
phenyllithium to BHPC (18) resulted in the corresponding
tertiary alcohol in good yields (61% and 65%, respectively).
Especially notable was the addition of methyllithium to 18.
The resulting product 20 was obtained in 72% yield as a
single diastereomer. A X-ray analysis of the product
proved, that the (S ,S)-, (R ,R)-diastereomer was the sole
p
p
diastereomer obtained. This can be explained by the con-
5
mol% Pd(PPh3)4,
O
O
1.3 equiv. Cs CO
2
3,
O
O
NEt2 1.3 equiv. TIPS-SH
NEt2
toluene, 100 ˚C, 16 h
I
38%
S
Si
14
15
Scheme 5. Palladium-catalyzed C–S-bond-formation of 14.
p p
Fig. 2. X-ray structure of (R ,R)/(S ,S)-20, only one enantiomer is shown.

M. Kreis et al. / Journal of Organometallic Chemistry 691 (2006) 2171–2181
2175
catalyst ligands. Additionally, [2.2]paracyclophane deriva-
tives with a stereogenic center in a-position to the
[
2.2]paracyclophane backbone were synthesized diastere-
OH
AcOH
H O
0
0
oselectively. For one of these, 4-hydoxy-5-[1 -hydroxy-1 -
phenylethyl)-[2.2]paracyclophane, the X-ray structure was
determined to elucidate the three-dimensional structure
and relative configuration.
-
2
OH
rac)-19
O
(
(rac)-21
Scheme 7. Elimination of water from 19.
3. Experimental
3
.1. General procedure
Having established a route to disubstituted [2.2]paracyc-
lophane-derivatives with a stereogenic center in a-position,
we tried to synthesize the mono-substituted analogues (see
Schemes 8).
Starting from [2.2]paracyclophane, the synthesis of 4-
acetyl-[2.2]paracyclophane (23) with acetyl chloride and
All reactions were carried out under argon atmosphere.
FHPC, AHPC and BHPC were synthesized according to
literature. Other reagents were commercially available
and used without further purification. H and C NMR
spectra were recorded on a Bruker AC300 (250 MHz/
1
13
TiCl proceeded in 61% isolated yield [21]. Reduction with
4
67 MHz), Bruker AM400 (400 MHz/100 MHz) or Bruker
NaBH and Ti(OiPr) resulted in the corresponding sec-
4
4
DRX500 (500 MHz/125 MHz), using CDCl as the solvent
and shift reference (CHCl 7.26 ppm/77.00 ppm). Signals
ondary alcohol in good 86% yield but poor 47% diastereo-
meric excess (not shown). Superior results could be
3
3
with an asterix * are interchangeable among themselves.
The MS spectras were recorded on a Finnigan MAT 90.
Elemental analyses were measured on a Heraeus CHN–
O-Rapid. The IR spectras were recorded on a Bruker IFS
achieved by reductive amination of 23 with NH in ethanol
3
and subsequent treatment with NaBH . The resulting pla-
4
nar- and central-chiral 1-[2.2]paracyclophane-4-ylethyl-
amine (24) could be obtained in 66% yield and 63%
diastereomeric excess. Further purification by column
chromatography resulted in a diastereomeric excess
8
2
8. Optical rotations were determined on a Perkin Elmer
41 polarimeter (Na, 589 nm). Solvents were purified
according to standard procedures.
>95%. Since the synthesis of enantiomerically pure 23 is
known [22], 24 can be synthesized enantiomerically pure
as well. An upscaling of the reaction to 5 g of starting mate-
rial did not pose any obstacles, thus allowing the utilization
of 24 as planar- and central-chiral phenyl ethylamine ana-
logue for various applications.
3.2. General procedure for the synthesis of
perfluoroalkanesulfonic acid esters
A 50-ml Schlenk-flask was flame-dried under a stream of
argon and allowed to cool to room temperature. It was
charged with hydroxy-[2.2]paracyclophane (1.0 equiv.)
and mineral oil free NaH or DBU (5.0 equiv.) in abs. tolu-
ene or DME under an argon atmosphere. The reaction
mixture was cooled to 0 ꢁC and trifluoromethanesulfonic
acid anhydride or nonafluorobutanesulfonic acid fluoride
In summary, we were able to synthesize a variety of 4,5-
disubstituted 4-perfluoroalkanesulfonic acid- or 4-iodo-
[
2.2]paracyclophane derivatives as starting materials for
two novel cross-coupling reactions. With two of these, a
Hartwig–Buchwald-amination and a palladium-catalyzed
C–S-bond forming reaction were exemplified, resulting in
a heteroatom-variation of previously successfully employed
(2.5 equiv.) was added slowly. The suspension was stirred
for another 5 min at 0 ꢁC and was subsequently warmed
to room temperature and stirred for 24 h. Saturated
NH Cl and diethyl ether were added and the mixture
4
aq
O
was transferred into a separatory funnel and the organic
layer was washed with brine. The collected organic layers
were dried with Na SO , filtered, and concentrated in
TiCl4,
Cl
O
2
4
vacuo.
CH Cl -78 ˚C RT
2
2,
16 h
2
2
61%
(rac)-23
3
[
.3. Nonafluorobutanesulfonic acid-(5-formyl-
2.2]paracyclophane-4-yl)ester (Table 1, entry 3)
1
2
3
) NH in EtOH
Ti(OiPr)4
EtOH, 60 ˚C, 6 h
The product was synthesized in DME with NaH as base
NH2
on a 100-mg (0.35 mmol) scale. The crude product was
purified by flash chromatography (cyclohexane/DME
2
pound as a white waxy solid. R = 0.19 (cyclohexane/
DME 20:1); H NMR (250 MHz, (CD ) CO): d = 10.17
) NaBH4, 0 ˚C,
3
h
0:1) to yield 180 mg (0.34 mmol, 95%) of the title com-
66%, 63% de
(rac)-24
f
1
Scheme 8. Diastereoselective synthesis of 1-[2.2]paracyclophane-1-yl-eth-
3 2
ylamine (24).
(s, 1H, CHO), 7.07 (d, J = 8.0 Hz, 1H, H-7*), 6.94 (d,

2176
M. Kreis et al. / Journal of Organometallic Chemistry 691 (2006) 2171–2181
J = 8.0 Hz, 1H, H-8*), 6.82 (dd, J = 7.9 Hz, 1.9 Hz, 1H,
H ), 6.77 (dd, J = 8.0 Hz, 1.9 Hz, 1H, H ), 6.65 (dd,
NMR (62.5 MHz, (CD ) CO): d = 193.9 (CHO), 145.8
3 2
(q), 144.4 (q), 141.2 (q), 140.7 (q), 140.1 (q), 139.6 (t),
136.3 (t), 135.6 (q), 135.4 (t), 134.8 (t), 134.3 (t), 133.6 (t),
133.0 (q), 131.9 (t), 131.1 (t, 2C, Ph–C-2*), 130.4 (t, 2C,
Ph–C-3*), 36.3, 35.8, 35.6, 32.6 (Pc–C-1, C-2, C-9, C-10)
ppm; FTIR (KBr) m = 2937, 1672, 1597, 1423, 1242, 968,
Ar
Ar
J = 7.9 Hz, 1.9 Hz, 1H, H ), 6.45 (dd, J = 7.9 Hz,
Ar
1
7
.9 Hz, 1H, H ), 4.20–3.95 (m, 1H, CH ), 3.55–2.95 (m,
Ar
2
1
3
H, CH ) ppm;
C NMR (62.5 MHz, (CD ) CO):
2
3 2
d = 189.8 (CHO), 148.9 (q), 147.7 (q), 142.1 (q), 142.1 (t),
ꢀ
1
+
1
1
3
40.9 (t), 137.7 (t), 135.6 (t), 135.5 (q), 134.6 (t), 132.9 (t),
883 cm ; EI-MS m/z (relative intensity) 610 (14) [M ],
+
+
þ
31.2 (q), 130.6 (t), 115–100 (m, 4C, C F ), 35.3, 35.1,
223 (43) [PcO ], 105 (54) [PhCO ], 104 (78) ½C H ꢁ, 43
4
9
8
8
1
9
+
4.3, 32.0 (Pc–C-1, C-2, C-9, C-10) ppm; F NMR
(100) [C H O ]; HRMS (m/z) C H F O S: calc.
2 3 27 19 9 4
(
376 MHz, (CD ) CO): d = ꢀ81.0 to ꢀ81.1 (m, 3F, CF ),
610.0860, found 610.0865.
3
2
3
ꢀ
110.0 to ꢀ110.1 (m, 2F, CF ), ꢀ121.1 to ꢀ121.2 (m,
2
2
F, CF ), ꢀ126.2 to ꢀ126.3 (m, 2F, CF ) ppm; FTIR
3.6. Trifluormethanesulfonic acid-(5-acetyl-[2.2]para-
cyclophane-4-yl)ester (Table 1, entry 9)
2
2
(
8
2
KBr) m = 2939, 1689, 1596, 1474, 1398, 1354, 1205, 1143,
ꢀ
1
+
85 cm , EI-MS m/z (relative intensity) 534 (34) [M ],
+
+
51 (42) [M –Nf], 147 (47) [M –Nf–C H ], 104 (100)
The product was synthesized in toluene with DBU as
base on a 500-mg (1.88 mmol) scale. The crude product
was purified by flash chromatography (cyclohexane/
DME/triethylamine 20:1:1) to yield 188 mg (0.472 mmol,
25%) of the title compound as a white waxy solid in a mix-
8
8
þ
½
C H ꢁ; HRMS (m/z) C H SO F : calc. 534.0547, found
8
8
21 15
4 9
5
34.0551.
3
[
.4. Trifluormethanesulfonic acid-(5-benzyl-
2.2]paracyclophane-4-yl)ester (Table 1, entry 5)
ture of ketone and enol form. R = 0.35 (cyclohexane/
DME/triethylamine 20:1:1); H NMR (250 MHz, CDCl ):
f
1
3
The product was synthesized in toluene with NaH as
d = 6.98 (dd, J = 7.9 Hz, 1.5 Hz, 1H, H ), 6.91 (d,
Ar
base on a 200-mg (0.61 mmol) scale. The crude product
was purified by flash chromatography (cyclohexane/DME
J = 7.9 Hz, 1H, H ), 6.5–6.0 (m, 4H, H ), 3.5–2.2 (m,
Ar
Ar
1
3
8H, CH ), 2.18 (s, 3H, Me) ppm, C NMR (62.5 MHz,
2
2
0:1) to yield 258 mg (0.56 mmol, 92%) of the title com-
CDCl ): A total attribution of the signals was not possible
3
pound as a white waxy solid. R = 0.34 (cyclohexane/
due to the keto-enol tautomerisation. Therefore only
unambiguous carbonyl carbon of the keto form is given.
d = 204.4 (CO) ppm; FTIR (KBr, tautomeric mixture)
m = 3506, 2930, 2854, 1614, 1418, 1210, 909, 797,
f
1
DME 20:1); H NMR (400 MHz, CDCl ): d = 7.77 (d,
3
J = 6.6 Hz, 2H, Ph–H-2), 7.56 (tt, J = 7.6 Hz, 1.3 Hz,
1
H, Ph–H-4), 7.41 (t, J = 7.6 Hz, 2H, Ph–H-3), 6.95–6.90
ꢀ1
+
(
m, 2H, Pc–H ), 6.71 (d, J = 7.9 Hz, 1H, Pc–H-7 or H-
732 cm ; EI-MS m/z (relative intensity) 398 (22) [M ],
Ar
+
þ
þ
8
1
9
1
), 6.65–6.60 (m, 3H, Pc–H ), 3.35 (ddd, J = 13.7 Hz,
265 (15) [M ꢀ Tf], 161 (62) ½M ꢀ SO CF ꢀ C H ꢁ,
þ
8
Ar
2
3
8
8
0.0 Hz, 3.7 Hz, 1H, CH ), 3.19 (ddd, J = 13.2 Hz,
104 (100) ½C H ꢁ; HRMS (m/z) C H F O S: calc.
2
8
19 17
3
4
.8 Hz, 4.4 Hz, 1H, CH2), 3.01 (ddd, J = 13.1 Hz,
0.1 Hz, 3.7 Hz, 1H, CH ), 2.95–2.70 (m, 4H, CH ), 2.53
398.0799, found 398.0794.
2
2
1
3
(
ddd, J = 13.7 Hz, 8.9 Hz, 4.9 Hz, 1H, CH ) ppm;
C
3.7. (R ,S)-Trifluormethanesulfonic acid-(4-[2.2]para-
p
2
0
NMR (100 MHz, CDCl ): d = 192.6 (CHO), 144.0 (q),
cyclophanyl)-5-phenyl-(1 -phenylethyliminophenylmethyl)-
ester (2)
3
1
42.2 (q), 139.4 (q), 138.7 (q), 138.1 (q), 137.4 (t), 133.9
(
(
3
t), 133.8 (q), 133.6 (t), 132.6 (t), 132.2 (t), 132.1 (t), 131.2
q), 130.5 (t, 2C, Ph–C-2*), 129.6 (t), 128.5 (t, 2C, Ph–C-
The product was synthesized in toluene with NaH as
base in a 200-mg (0.463 mmol) approach. The crude prod-
uct was purified by flash chromatography (cyclohexane/
DME/triethylamine 40:2:1) to yield 128 mg (0.227 mmol,
*), 118.3 (q, J = 320.4 Hz, 1C, CF ), 34.9, 34.3, 34.2,
3
1
9
3
1.1 (Pc–C-1, C-2, C-9, C-10) ppm; F NMR (376 MHz,
CDCl ): d = ꢀ73.8 (s, 3F, CF ) ppm; FTIR (KBr)
3
3
ꢀ
1
m = 2939, 1670, 1597, 1420, 1215, 969, 882 cm ; EI-MS
49%) of the title compound as an orange-yellow solid.
+
+
293
589
m/z (relative intensity) 460 (9) [M ], 223 (16) [M ꢀ Tf],
R = 0.38 (cyclohexane/DME/triethylamine 40:2:1); ½aꢁ
¼
f
þ
+
ꢂ
1
1
04 (18) ½C
8
H ꢁ, 43 (100) [C H O ]; HRMS (m/z)
þ50:5 (c = 1.00 g/100 ml, CHCl ); H NMR (250 MHz,
8
2
3
3
C H F O S: calc. 460.0956, found 460.0959.
CDCl ): d = 7.6ꢀ7.5 (m, 2H, H ), 7.45–7.20 (m, 9 H,
2
4
19
3
4
3
Ar
H ), 6.82 (bd, J = 8.0 Hz, 1H, H ), 6.70–6.65 (m, 2H,
Ar
Ar
3
[
.5. Nonafluorobutanesulfonic acid-(5-benzyl-
2.2]paracyclophane-4-yl)ester (Table 1, entry 6)
H ), 6.58 (d, J = 7.9 Hz, 1H, Pc–H-7*), 6.48 (d, J =
7.9 Hz, 1H, Pc–H-8*), 5.13 (q, J = 6.4 Hz, 1H, NCH(Ph)-
Ar
Me), 3.5–2.7 (m, 8H, CH ), 1.83 (d, J = 6.4 Hz, 3H, Me)
2
1
3
The product was synthesized in DME with NaH as base
ppm; C NMR (100 MHz, CDCl ): d = 160.6 (CN),
3
on a 200-mg (0.61 mmol) scale. No further purification was
necessary to yield 371 mg (0.608 mmol, 99%) of the title
compound as a white waxy solid. H NMR (250 MHz,
141.4 (q), 139.3 (q), 138.8 (q), 135.9 (q), 135.8 (t), 134.7
(t), 134.2 (q), 133.1 (q), 132.4 (t), 132.2 (t), 132.1 (t),
130.4 (t), 129.1 (t), 128.8 (2C, Ph–C-2*), 128.6 (q), 128.3
(2C, Ph–C-3*), 127.9 (2C, Ph–C-2*), 126.7 (t), 126.6 (2C,
1
(
CD ) CO): d = 7.79 (d, J = 7.5 Hz, 2H, Ph–H-2), 7.65–
3 2
7
6
.55 (m, 1H, Ph–H-4), 7.47 (t, J = 7.5 Hz, Ph–H-3), 6.9–
Ph–C-3*), 118.1 (q, 1C, CF ), 61.8 (CHNMe), 34.7, 34.5,
33.5, 30.9 (Pc–C-1, C-2, C-9, C-10), 27.3 (Me) ppm; FTIR
3
1
3
.7 (m, 6H, Pc–H ), 3.5–2.5 (m, 8H, CH ) ppm;
C
Ar
2

M. Kreis et al. / Journal of Organometallic Chemistry 691 (2006) 2171–2181
2177
(
7
4
KBr) m = 2936, 1893, 1615, 1494, 1386, 1208, 963,
3.10. Benzyl-(5-benzoyl-[2.2]paracyclophane-4-yl)amine
(8)
ꢀ
1
+
00 cm ; EI-MS m/z (relative intensity) 563 (2) [M ],
+
þ
þ
30 (3) [M ꢀ Tf], 105 (4) ½C
8
H ꢁ, 43 (100) ½C
3
H ꢁ; HRMS
9
7
(
m/z) C H F NO S: calc. 563.1742, found 563.1747.
A sealable tube was charged with 7 (101 mg, 0.22 mmol,
3
2
28
3
3
1
.0 equiv.), K PO (140 mg, 0.66 mmol, 3.0 equiv.),
3
4
3
[
(
.8. (R ,S)-Trifluormethanesulfonic acid-(4-
p
Pd (dba) (6 mg, 10 lmol, 5 mol%) and (rac)-Binap
2 3
0
2.2]paracyclophanyl)-5-(1 -phenylethyliminoethyl)ester
4)
(14 mg, 20 lmol, 10 mol%). The vial was sealed afterwards.
The sealed tube was evacuated and refilled with argon. This
procedure was repeated three times. Dry toluene (5 ml) and
benzyl amine (150 mg, 1.40 mmol, 6.4 equiv.) were added
subsequently via syringe. The solution turned deep red
and was warmed to 70 ꢁC for 24 h. After cooling to room
temperature, 5 ml of saturated aqueous Na CO solution
The product was synthesized in toluene with DBU as
base in a 250-mg (0.676 mmol) approach. The crude prod-
uct was purified by flash chromatography (cyclohexane/
DME/triethylamine 20:1:1) to yield 140 mg (0.279 mmol,
2
3
4
1%) of the title compound as an orange-yellow oil.
were added. The reaction contents were transferred to a
separatory funnel and extracted twice with diethyl ether.
The combined organic layers were dried with Na SO , fil-
1
R = 0.47 (cyclohexane/DME/triethylamine 20:1:1);
NMR (250 MHz, CDCl ): d = 7.59 (d, J = 7.2 Hz, 2H,
H
f
3
2
4
Ph–H-2), 7.42 (t, J = 7.2 Hz, 2H, Ph–H-3), 7.31 (t,
J = 7.2 Hz, 1H, Ph–H-4), 6.99 (dd, J = 7.7 Hz, 1.4 Hz,
tered, and concentrated in vacuo. The crude product was
purified by flash chromatography (cyclohexane/dichloro-
methane 2:1) to yield 43 mg (0.10 mmol, 47%) of the title
1
6
1
H, Pc–H ), 6.76 (d, J = 8.0 Hz, 1H, Pc–H-7 or H-8),
Ar
.65-6.55 (m, 2H, Pc–H ), 6.46 (dd, J = 7.9 Hz, 1.8 Hz,
compound as a yellow oil. R = 0.06 (cyclohexane/dichlo-
Ar
f
1
H, Pc–H ), 6.45-6.35 (m, 1H, Pc–H ), 4.89 (q,
romethane 2:1); H NMR (400 MHz, CDCl ): d = 7.60
Ar
Ar
3
J = 6.6 Hz, 1H, NCH(Ph)Me), 3.65 (ddd, J = 14.0 Hz,
(d, J = 7.5 Hz, 2H, H ), 7.50 (t, J = 7.7 Hz, 1H, H ),
Ar
Ar
9
3
.5 Hz, 1.5 Hz, 1H, CH ), 3.4–2.6 (m, 7H, CH ), 2.24 (s,
H, Me), 1.59 (d, J = 6.6 Hz, 3H, Me) ppm; C NMR
7.36 (t, J = 7.7 Hz, 2H, H ), 7.20–7.05 (m, 4H, H ),
Ar Ar
2
2
1
3
6.59 (d, J = 8.3 Hz, 2H, H ), 6.55 (d, J = 7.6 Hz, 2H,
Ar
(
100 MHz, CDCl ): 161.5 (CN), 145.0 (q), 142.6 (q),
H ), 6.29 (d, J = 7.7 Hz, 1H, H ), 4.30 (d, J = 14.5 Hz,
3
Ar
Ar
1
40.1 (q), 139.6 (t), 135.6 (t), 135.0 (q), 133.1 (t), 132.6
1H, CHHNH), 3.99 (d, J = 14.5 Hz, 1H, CHHNH), 3.42
(
q), 132.4 (q), 131.4 (t), 130.2 (t), 129.4 (q), 127.8 (t),
(ddd, J = 12.6 Hz, 9.2 Hz, 2.8 Hz, 1H, Pc–CH ), 3.22
2
1
1
28.3 (2C, Ph–C-2*), 126.8 (2C, Ph–C-3*), 126.7 (t),
(ddd, J = 13.0 Hz, 9.1 Hz, 6.3 Hz, 1H, Pc–CH ), 3.1–3.0
2
18.3 (q, 1C, CF ), 60.4 (CH), 34.9, 34.4, 33.0, 30.7 (Pc–
(m, 1H, Pc–CH ), 2.9–2.6 (m, 4H, Pc–CH ), 2.55–2.45
3
2
2
1
3
C-1, C-2, C-9, C-10), 26.9 (Me), 24.7 (Me) ppm; FTIR
(m, 1H, Pc–CH ) ppm; C NMR (100 MHz, CDCl ): d
2 3
ꢀ
1
(
KBr) m = 2934, 1579, 1420, 1204, 843 cm ; EI-MS m/z
198.0 (CHO), 143.3 (q), 142.0 (q), 141.1 (q), 139.5 (q),
139.1 (t), 138.4 (q), 132.2 (t, 2C), 131.9 (t), 131.7 (q),
130.9 (t), 130.5 (q), 129.3 (t, 2C), 128.9 (t), 128.5 (t),
128.4 (q), 128.3 (t, 2C), 128.1 (t, 2C), 127.2 (t), 126.9 (t),
+
þ
2
(
1
relative intensity) 501 (2) [M ], 161 (62) ½C H O ꢁ,
10
11
þ
+
04 (59) ½C H ꢁ, 84 (100) [C H N ]; HRMS (m/z)
8
8
5
10
C H F O NS: calc. 501.1586, found 501.1588.
2
7
26
3
3
1
25.4 (q), 53.7 (CH N), 36.0, 34.9, 34.3, 34.1 (Pc–C-1, C-
2
3
[
(
.9. (R ,S)- and (S ,S)-Trifluormethanesulfonic acid-(4-
p
2, C-9, C-10) ppm; FTIR (KBr) m = 3416, 2929, 1623,
p
0
ꢀ1
2.2]paracyclophanyl)-5-(1 -phenylmethyliminoethyl)ester
6)
1575, 1495, 1285, 1101, 965, 698 cm ; EI-MS m/z (relative
+
+
intensity) 417 (64) [M ], 313 (35) [M ꢀ C H ], 312 (80)
8
8
+ +
[
M ꢀ C H O], 234 (98) [M ꢀ C H ꢀ C H N] 131 (65)
+
þ
8
7
5
6
5
7
8
To a stirred solution of (rac)-5 (214 mg, 0.557 mmol) and
[C H N ], 103 ½C H ꢁ; HRMS (m/z) C H ON: calc.
9
9
7
30 27
dibutyltindiacetate (39 mg, 0.11 mmol) in 50 ml toluene,
S)-phenyl ethylamine (135 mg, 1.11 mmol) was added.
417.2092, found 417.2094.
(
The flask was equipped with a Dean–Stark-trap and a
reflux-condenser and was refluxed for 24 h. Water and
diethyl ether was added and the mixture was transferred
into a separatory funnel and the organic layer was washed
with brine. The collected organic layers were dried with
Na SO , filtered, and concentrated in vacuo. The crude
3.11. 4-(2-Methoxy-ethoxymethoxy)-[2.2]paracyclophane
(11)
A 25-ml Schlenk-flask was flame-dried under a stream
of argon and allowed to cool to room temperature. It was
charged with 4-hydroxy-[2.2]paracyclophane (1.0 equiv.)
and mineral oil-free NaH (96 mg, 4.0 mmol) in abs.
DMF under an argon atmosphere. MEM-Cl (142 mg,
1.15 mmol) was added slowly over a period of 15 min.
The reaction mixture was stirred for 16 h at room temper-
ature. NH4aq and diethyl ether were added and the mix-
ture was transferred into a separatory funnel and the
organic layer was washed with brine. The collected
organic layers were dried with Na SO , filtered, and
2
4
product was purified by column chromatography (cyclo-
hexane/triethylamine 33:1) to yield 167 mg (0.343 mmol,
6
2%) of the title compound as an orange oil. Due to partial
(
ca. 10%) degradation during the column chromatography
back to the starting material, no NMR assignment of the
signals was done. EI-MS m/z (relative intensity) 487 (4)
+
+
+
[
½
M ], 354 (5) [M ꢀ Tf], 105 (77) [PhCO ], 104 (13)
þ þ
8 3
C H ꢁ, 43 (100) ½C H ꢁ; HRMS (m/z) C H F NO S:
8
7
26 24
3
3
2
4
calc. 487.1429, found 487.1424.
concentrated in vacuo. The crude product was purified

2178
M. Kreis et al. / Journal of Organometallic Chemistry 691 (2006) 2171–2181
by column chromatography (cyclohexane/ethyl acetate
:1) to yield 140 mg (0.50 mmol, 50%) of the title com-
ane, 0.57 ml, 0.74 mmol) was added slowly over a period
of 15 min. The solution was stirred for another 3 h at
ꢀ78 ꢁC. Diiodoethane (523 mg, 1.86 mmol) was added
and the solution was allowed to slowly warm up to room
temperature over a period of 5 h. 1 M hydrochloric acid
and dichloromethane were added and the mixture was
transferred into a separatory funnel and the organic layer
was washed with brine. The collected organic layers were
dried with Na SO , filtered, and concentrated in vacuo.
5
pound as a white solid. R = 0.41 (cyclohexane/ethyl ace-
f
1
tate 5:1); H NMR (250 MHz, CDCl ): d = 6.79 (dd,
3
J = 7.8 Hz, 1.8 Hz, 1H, H ), 6.54 (dd, J = 7.8 Hz,
Ar
1
.9 Hz, 1H, H ), 6.46–6.38 (m, 3H, H ), 6.29 (dd,
Ar Ar
J = 7.7 Hz, 1.6 Hz, 1H, H ), 5.96 (d, J = 1.8 Hz, 1H,
Ar
Pc–H-5), 5.27 (d, J = 6.7 Hz, 1H, OCHHO), 5.16 (d,
J = 6.7 Hz, 1H, OCHHO), 4.00–3.80 (m, 2H, OCH CH ),
2
2
2
4
3
.60–3.57 (m, 2H, OCH CH ), 3.50–3.35 (m, 1H, Pc–
The crude product was purified by column chromatogra-
phy (cyclohexane/DME 20:1) to yield 182 mg (0.41 mmol,
2
2
CH ), 3.41 (s, 3H, Me), 3.15–2.95 (m, 6H, Pc–CH ),
2
2
2
.62 (ddd, J = 12.9 Hz, 8.6 Hz, 7.3 Hz, 1H, Pc–CH2)
66%) of the title compound as a light yellow solid.
1
ppm; FTIR (KBr) m = 3362, 2927, 1701, 1597, 1416,
1
R = 0.12 (cyclohexane/DME 20:1), H NMR (500 MHz,
f
ꢀ
1
160, 718 cm ; EI-MS m/z (relative intensity) 312 (16)
CDCl ): d = 7.15 (dd, J = 7.9 Hz, 1.6 Hz, 1H, H ), 6.67
3
Ar
+
+
+
[
[
M ], 224 (33) [PcOH ], 208 (10) [M ꢀ C H ], 120 (39)
(dd, J = 7.9 Hz, 1.5 Hz, 1H, H ), 6.58 (d, J = 7.8 Hz,
8
8
Ar
+
þ
8
C H O ], 104 (100) ½C H ꢁ; HRMS (m/z) C H O :
1H, H-7*), 6.56–6.51 (m, 2H, H ), 6.44 (d, J = 7.8 Hz,
8
8
8
20 24
3
Ar
calc. 312.1725, found 312.1727.
1H, H-8*), 3.80 (dq, J = 14.2 Hz, 7.1 Hz, 1H, NCHH),
3.56 (dq, J = 14.2 Hz, 7.1 Hz, 1H, NCHH), 3.50–3.35 (m,
3.12. N-Methyl-(N-4-[2.2]paracyclophanyl)carbamic acid
methyl ester (13)
7H, CH ), 3.2–3.0 (m, 7H, CH ), 2.9–2.8 (m, 1H, CH ),
2
2
2
1.49 (t, J = 7.1 Hz, 3H, Me), 1.22 (t, J = 7.1 Hz, 3H, Me)
1
3
ppm; C NMR (125 MHz, CDCl ): d = 152.6 (q), 149.0
3
A 50 ml flask was charged with N-methyl-(N-4-
2.2]paracyclophanyl)amine (41 mg, 0.17 mmol), DMAP
63 mg, 0.52 mmol) and methoxycarbamic acid chloride
33 mg, 0.35 mmol) in 1 ml pyridine and 10 ml CHCl3.
(q), 145.2 (q), 139.1 (q), 138.6 (q), 134.3 (t), 133.2 (t),
132.9 (t), 130.5 (t), 128.8 (t), 128.5 (t), 103.5 (C-4), 42.3
(NCH ), 42.1 (NCH ), 39.1, 34.5, 33.0, 31.7 (C-1, C-2, C-
[
(
(
2
2
9, C-10), 14.7 (Me), 13.4 (Me) ppm; FTIR (KBr)
ꢀ1
The reaction mixture was stirred for 16 h at room temper-
ature. Water and diethyl ether were added and the mixture
was transferred into a separatory funnel and the organic
layer was washed with brine. The collected organic layers
were dried with Na SO , filtered, and concentrated in
m = 2974, 2933, 1720, 1421, 1239, 1153, 958, 799 cm ;
+
EI-MS m/z (relative intensity) 449 (13) [M ], 323 (30)
+
þ
[M ꢀ I], 100 (100) ½CONEt ꢁ; HRMS (m/z) C H O NI:
2
21 24
2
calc. 449.0851, found 449.0847.
2
4
vacuo. The crude product was purified by column chroma-
tography (cyclohexane/ethyl acetate 5:1) to yield 34 mg
3.14. O-(5-(4-Triisopropylsilanylsulfuryl)-
[2.2]paracyclophanyl)-N,N-diethylcarbamate (15)
(
0.12 mmol, 68%) of the title compound as a yellow solid.
1
R = 0.35 (cyclohexane/ethyl acetate 5:1); H NMR
A sealable tube was charged with 14 (270 mg,
0.601 mmol,), Cs CO (255 mg, 0.781 mmol) and
f
(
400 MHz, CDCl ): d = 6.70–6.60 (m, 2H, H ), 6.53 (dd,
3 Ar
2
3
J = 8.0 Hz, 1.5 Hz, 1H, H ), 6.45–6.30 (m, 4H, H ),
Pd(PPh ) (42 mg, 36 lmol, 5 mol%). The vial was sealed
Ar
Ar
3 4
3
.70 (bs, 3H, Me), 3.44 (s, 3H, Me), 3.20–2.90 (m, 8H,
afterwards. The sealed tube was evacuated and refilled with
argon. This procedure was repeated three times. Dry tolu-
ene (5 ml) and TIPS-SH (149 mg, 0.781 mmol) were added
subsequently via syringe. The solution turned deep red and
was warmed to 100 ꢁC for 16 h. After cooling to room tem-
1
3
CH ) ppm;
C NMR (100 MHz, CDCl ): d = 156.2
3
2
(
CO), 141.1 (q), 139.7 (q), 139.6 (q), 139.2 (q), 139.1 (t),
135.2 (t), 135.0 (t), 132.8 (t), 132.3 (t), 132.1 (q), 132.0 (t),
128.1 (t), 37.5 (Me), 35.3, 35.2, 35.0 (C-1, C-9, C-10),
32.0 (Me), 26.8 (C-2) ppm; FTIR (KBr) m = 3316, 2927,
1
perature, 5 ml of saturated aqueous NH Cl solution were
4
ꢀ
1
703, 1595, 1448, 1347, 1152, 1063, 1016, 898, 797 cm
;
added. The reaction contents were transferred to a separa-
tory funnel and extracted twice with diethyl ether. The
combined organic layers were dried with Na SO , filtered,
+
EI-MS m/z (relative intensity) 295 (76) [M ], 281 (16)
+
+
[
[
M ꢀ CH ], 191 (100) [M ꢀ C H ], 132 (50)
3
+
8
8
2
4
C H NMe ]; HRMS m/z C H NO : calc. 295.1572,
and concentrated in vacuo. The crude product was purified
by flash chromatography (cyclohexane/ethyl acetate 9:1) to
yield 115 mg (0.225 mmol, 38%) of the title compound with
ca. 20% deprotected arylthiol (due to deprotection during
8
8
19 21
2
found 295.1570.
3.13. O-(5-(Iodo)-[2.2]paracyclophanyl)-N,N-
diethylcarbamate (14)
the column chromatography) as a yellow oil. R = 0.28
f
1
(
cyclohexane/ethyl acetate 9:1); H NMR (250 MHz,
A 25-ml Schlenk-flask was flame-dried under a stream of
argon and allowed to cool to room temperature. It was
charged with O-(4-[2.2]paracyclophanyl)-N,N-diethylcar-
bamate (200 mg, 0.62 mmol) and TMEDA (86 mg,
CDCl ) d = 6.97 (dd, J = 7.8 Hz, 1.7 Hz, 1H, H ), 6.86
3 Ar
(dd, J = 7.8 Hz, 1.9 Hz, 1H, H ), 6.75–6.68 (m, 2H,
Ar
H ), 6.60–6.40 (m, 2H, H ), 3.90 (q, J = 7.1 Hz, 1H,
Ar
Ar
NCHHCH ), 3.7–2.7 (m, 11H, CH ), 1.55–1.40 (m, 3H,
3
2
1
3
0
.74 mmol) in abs. THF under an argon atmosphere. The
CH), 1.1–0.9 (m, 24H, Me) ppm; C NMR (62 MHz,
solution was cooled to ꢀ78 ꢁC and s-BuLi (1.3 M in hex-
CDCl ). Due to the arylthiol-byproduct a total assignment
3

M. Kreis et al. / Journal of Organometallic Chemistry 691 (2006) 2171–2181
2179
of the aromatic signals was impossible, therefore only the
aliphatic signals are given. d = 42.1, 35.2, 34.8, 34.5, 34.2,
another 30 min. Water and diethylether were added and
the mixture was transferred into a separatory funnel and
the organic layer was washed with brine. The collected
organic layers were dried with Na SO , filtered, and con-
3
1.6 (Pc–C-1, C-2, C-9, C-10, 2· NCH CH ), 18.5
2
3
(
CHCH ), 18.1 (Me), 18.0 (Me), 17.6 (CHCH ), 12.6,
3 3
2
4
1
1
5
2.2 (CH) ppm; FTIR (KBr) m = 2934, 2864, 1717, 1460,
centrated in vacuo. The crude product was purified by col-
umn chromatography (cyclohexane/DME 20:1) to yield
ꢀ
1
409, 1240, 1157, 883 cm , EI-MS m/z (relative intensity)
+
+
11 (1) [M ], 131 (100) [C H OMe ], HRMS (m/z)
81 mg (0.20 mmol, 65%) of the title compound as light yel-
6
7
1
C H NO SSi: calc. 511.2940, found 511.2940.
low crystals. R = 0.14 (cyclohexane/DME 20:1); H NMR
3
0
45
2
f
(
500 MHz, CDCl ): d = 7.53 (d, J = 7.2 Hz, 2H, Ph–H ),
3 Ar
0
0
3
[
.15. 4-Hydroxy-5-(1 -hydroxy-1 -methyl-ethyl)-
2.2]paracyclophane (17)
7.36 (t, J = 6.9 Hz, 2H, Ph–H ), 7.34 (t, J = 8.1 Hz, 1H,
Ph–H ), 7.30 (t, J = 7.5 Hz, 2H, Ph–H ), 7.25–7.15 (m,
Ar
Ar
Ar
3
H, Ph–H ), 7.07 (d, J = 6.6 Hz, 2H, Ph–H ), 6.94 (dd,
Ar Ar
A 25-ml Schlenk-flask was flame-dried under a stream of
J = 7.8 Hz, 1.9 Hz, 1H, Pc–H ), 6.6–6.4 (m, 3H, Pc–
Ar
argon and allowed to cool to room temperature. It was
charged with 16 (300 mg, 1.13 mmol) in abs. toluene under
an argon atmosphere. The solution was cooled to 0 ꢁC and
MeLi (1.6 M in diethylether, 1.7 ml, 2.7 mmol) was added
slowly over a period of 5 min. The solution was allowed
to slowly warm up to room temperature over a period of
H ), 6.48 (d, J = 7.5 Hz, 1H, Pc–H-7*), 6.24 (d,
J = 7.5 Hz, 1H, Pc–H-8*), 3.79 (s, 1H, OH), 3.26 (ddd,
Ar
J = 13.2H, 10.0 Hz, 3.5 Hz, 1H, CH ), 3.12 (ddd, J =
2
13.2 Hz, 9.4 Hz, 4.9 Hz, 1H, CH ), 3.06 (ddd, J = 13.2
2
Hz, 10.2 Hz, 3.1 Hz, 1H, CH ), 2.82 (ddd, J = 13.0 Hz,
2
10.3 Hz, 2.4 Hz, 1H, CH ), 2.64 (ddd, J = 13.3 Hz, 10.3
2
1
6 h. It was again cooled to 0 ꢁC and 10 ml water were
Hz, 5.4 Hz, 1H, CH ), 2.47 (ddd, J = 13.2 Hz, 9.9 Hz,
2
added and the suspension was stirred for another 30 min.
Water and dichloromethane were added and the mixture
was transferred into a separatory funnel and the organic
layer was washed with brine. The collected organic layers
were dried with Na SO , filtered, and concentrated in
vacuo. The crude product was purified crystallization
in cyclohexane/dichloromethane to yield 194 mg (0.688
mmol, 61%) of the title compound as yellow crystals. H
NMR (500 MHz, (CD ) CO): d = 9.73 (s, 1H, Pc–OH),
6
J = 7.9 Hz, 1.8 Hz, 1 H, H ), 6.65–6.55 (m, 2H, H ),
6
6.8 Hz, 1H, CH ), 2.32 (ddd, J = 14.1 Hz, 9.9 Hz, 6.8 Hz,
2
1H, CH ), 1.62 (ddd, J = 14.1 Hz, 9.8 Hz, 2.3 Hz, 1H,
2
1
3
CH2), C NMR (62.5 MHz, CDCl ): d = 154.8 (q), 149.4
3
(q), 146.0 (q), 141.7 (q), 139.8 (q), 139.0 (q), 135.4 (t),
133.2 (t), 132.1 (t), 131.7 (t), 129.2 (t), 128.1 (2C, Ph),
128.0 (2C, Ph), 127.7 (t), 127.0 (t), 126.9 (t), 126.6 (2C,
2
4
Ph), 125.4 (2C, Ph), 81.1 (CR OH), 36.3, 35.9, 33.9, 29.9
3
1
(Pc–C-1, C-2, C-9, C-10) ppm; FTIR (KBr) m = 3449,
ꢀ
1
2925, 1624, 1501, 762, 697 cm ; EI-MS m/z (relative
3
2
+
+
.78 (dd, J = 7.9 Hz, 1.9 Hz, 1H, H ), 6.69 (dd,
intensity) 404 (6) [M ], 388 (46) [M ꢀ H O], 283 (47)
þ
+ +
8
Ar
2
[M ꢀ C H ꢀ H O], 104 (10) ½C H ꢁ, 84 (100) [C H O ].
Ar
Ar
8
9
2
8
5
8
.20 (d, J = 7.5 Hz, 1H, H-7*), 6.04 (d, J = 7.5 Hz, 1H,
0
0
H-8*), 5.22 (s, 1H, C(Me) OH), 3.35–3.25 (m, 2H, CH ),
3.17. (R ,R) and (S ,S)-4-Hydroxy-5-(1 -hydroxy-1 -
p
2
2
p
3
.1–2.9 (m, 2H, CH ), 2.51 (ddd, J = 12.8 Hz, 10.1 Hz,
phenyl-ethyl)-[2.2]paracyclophane (20)
2
6
.0 Hz, 1H, CH ), 1.85 (s, 3H, Me), 1.50 (s, 3H, Me)
2
1
3
ppm; C NMR (125 MHz, (CD ) CO): d = 157.2 (q),
A 25-ml Schlenk-flask was flame-dried under a stream of
argon and allowed to cool to room temperature. It was
charged with 18 (300 mg, 0.914 mmol) in abs. toluene
under an argon atmosphere. The solution was cooled to
0 ꢁC and MeLi (1.6 M in diethylether, 1.4 ml, 2.1 mmol)
was added slowly over a period of 5 min. The solution
was allowed to slowly warm up to room temperature over
a period of 16 h. It was again cooled to 0 ꢁC and 10 ml
water were added and the suspension was stirred for
another 30 min. Water and diethylether were added and
the mixture was transferred into a separatory funnel and
the organic layer was washed with brine. The collected
organic layers were dried with Na SO , filtered, and con-
3
2
1
42.0 (q), 140.0 (q), 139.8 (q), 135.8 (t), 134.5 (t), 133.9
(
(
(
t), 133.4 (t), 130.8 (q), 130.0 (q), 130.0 (q), 128.8 (t), 77.6
CH), 37.4, 37.1, 35.6 (C-1, C-2, C-9*), 34.2 (Me), 31.6
C-10*), 30.8 (Me) ppm; FTIR (KBr) m = 3353, 2931,
ꢀ
1
1
2
600, 1416, 1145, 797 cm ; EI-MS m/z (relative intensity)
+
+
+
82 (1) [M ], 264 (28) [M ꢀ H O], 159 (100) [M ꢀ
2
H O ꢀ C H ]; HRMS (m/z) C H O : calc. 282.1620,
2
8
9
19 22
2
found 282.1625.
3
[
.16. 4-Hydroxy-5-(hydroxy-diphenyl-methyl)-
2.2]paracyclophane (19)
2
4
A 25-ml Schlenk-flask was flame-dried under a stream of
centrated in vacuo. The crude product was purified by crys-
tallization in cyclohexane/dichloromethane to yield 226 mg
(0.657 mmol, 72%) of the title compound as yellow crystals.
argon and allowed to cool to room temperature. It was
charged with 18 (100 mg, 0.305 mmol) in abs. toluene
under an argon atmosphere. The solution was cooled to
1
H NMR (250 MHz, (CD ) CO): d = 9.90 (s, 1H, PcOH),
3
2
0
ꢁC and PhLi (2.0 M in diethylether, 0.4 ml, 0.8 mmol)
7.86 (dd, J = 7.7 Hz, 1.3 Hz, 2H, Ph–H-2), 7.50 (t,
J = 7.7 Hz, 2H, Ph–H-3), 7.39 (t, J = 7.3 Hz, 1H, Ph–H-
was added slowly over a period of 5 min. The solution
was allowed to slowly warm up to room temperature over
a period of 16 h. It was again cooled to 0 ꢁC and 10 ml
water were added and the suspension was stirred for
4), 6.73 (d, J = 7.9 Hz, 1H, Pc–H ), 6.55–6.50 (m, 2H,
Ar
Pc–H ), 6.22 (d, J = 7.6 Hz, 1H, Pc–H-7*), 5.96 (d,
Ar
J = 7.6 Hz, 1H, Pc–H-8*), 5.77 (d, J = 7.7 Hz, 1H,

2180
M. Kreis et al. / Journal of Organometallic Chemistry 691 (2006) 2171–2181
Pc–HAr), 5.77 (s, 1H, C(Me)(Ph)OH), 3.39 (ddd,
(0.33 mmol, 66%) of the title compound as a light yellow
solid in 63% de. It was possible to separate the diastereo-
mers by column chromatography (dichloromethane/cyclo-
hexane 9:1, 1% triethylamine) to yield the excess
diastereomer with no detectable traces of the minor diaste-
reomer. Excess diastereomer (R ,S), (S ,R) respectively.
J = 12.7 Hz, 9.6 Hz, 3.6 Hz, 1H, CH ), 3.0–2.7 (m, 4H,
2
1
3
CH ), 2.5–2.2 (m, 3H, CH ), 1.89 (s, 3H, Me) ppm;
C
2
2
NMR (62.5 MHz, (CD ) CO): d = 156.7 (q), 148.8 (q),
3
2
1
(
41.5 (q), 140.8 (q), 140.1 (q), 136.2 (t), 134.1 (t), 133.6
q), 133.6 (t), 133.6 (t), 130.5 (q), 130.0 (t), 129.8 (2C,
Ph–C-2*), 129.6 (t), 129.2 (2C, Ph–C-3*), 128.9 (t), 80.8
CHOH), 37.3, 36.1, 35.7, 32.6 (Pc–C-1, C-2, C-9, C-10),
p
p
R = 0.17 (dichloromethane/cyclohexane 9:1, 1% triethyl-
f
1
(
amine); H NMR (excess diastereomer (R ,S) (S ,R),
p
p
2
1
8.5 (Me) ppm; FTIR (KBr) m = 3395, 2936, 1596, 1415,
250 MHz, CDCl ): d = 6.6–6.3 (m, 7H, H ), 4.06 (q,
3 Ar
ꢀ
1
273, 1058, 993, 911, 705 cm ; EI-MS m/z (relative inten-
J = 6.6 Hz, 1H, C-1), 3.55 (ddd, J = 13.1 Hz, 9.7 Hz,
2.3 Hz, 1H, CH ), 3.2–3.0 (m, 6H, CH ), 2.91 (ddd,
+
+
sity) 344 (2) [M ], 326 (5) [M ꢀ H O], 221 (38)
2
2
2
+
þ
[
[
M ꢀ H O ꢀ C H ], 104 (29) ½C
8
H ꢁ, 57 (100)
J = 13.2 Hz, 10.7 Hz, 5.9 Hz, 1H, CH2), 1.52 (d,
2
8
9
8
+
13
C H O ]; HRMS (m/z) C H O : calc. 344.1776, found
J = 6.6 Hz, 3H, Me) ppm; C NMR (excess diastereomer
3
5
24 24
2
3
44.1778.
(R ,S) (S ,R), 100 MHz, CDCl ): d = 144.5 (q), 139.7 (q),
p
p
3
139.0 (q), 138.9 (q), 136.8 (q), 135.1 (t), 133.0 (t), 132.6
(
(
t), 131.6 (t), 131.1 (t), 129.4 (t), 128.4 (t), 46.8
4
.18. 6-Benzhydrylidene-tricyclo-[8.2.2.2 ]hexadeca-
,7
3
1
CH(NH )Me), 34.9, 34.8, 34.3, 32.9 (Pc–C-1, C-2, C-9,
2
(13),4(16),7(15),10(14),11-pentaen-5-one (21)
C-10), 20.9 (Me) ppm; minor diastereomer (R ,S) (S ,R)
p
p
respectively R = 0.25 (dichloromethane/cyclohexane 9:1,
f
A 50-ml flask was charged with the crude product of the
1
1
% triethylamine); H NMR (minor diastereomer (R ,R)
p
synthesis of 19 and ethyl acetate/acetic acid 10:1 and was
stirred for 1 h at room temperature. It was concentrated
in vacuo and the crude product was purified by column
chromatography (cyclohexane/DME 20:1) to yield 64 mg
(S ,S), 250 MHz, CDCl ): d = 6.6–6.3 (m, 7H, H ), 4.15
p 3 Ar
(q, J = 6.6 Hz, 1H, C-1), 3.41 (ddd, J = 13.2 Hz, 9.7 Hz,
2
1
.1 Hz, 1H, CH ), 3.2–3.0 (m, 6H, CH ), 2.75–2.65 (m,
2 2
1
3
H, CH ), 1.19 (d, J = 6.6 Hz, 3H, Me) ppm; C NMR
2
(
0.16 mmol, 54% over 2 steps) of the title compound as
(
minor diastereomer (R ,R) (S ,S), 100 MHz, CDCl ):
p p 3
light yellow crystals. R = 0.08 (cyclohexane/DME 20:1);
f
d = 145.8 (q), 139.7 (q), 139.1 (q), 139.0 (q), 135.3 (q),
1
H NMR (250 MHz, CDCl ): d = 7.4–7.0 (m, 10 H, Ph–
3
1
1
34.7 (t), 133.3 (t), 132.6 (t), 131.5 (t), 130.5 (t), 129.0 (t),
H ), 6.9–6.7 (m, 4H, Pc–H ), 6.04 (d, J = 6.6 Hz, 1H,
Ar
Ar
27.7 (t), 47.8 (CH(NH )Me), 34.9, 34.8, 33.8, 32.9 (Pc–
2
Pc–H-7*), 5.47 (d, J = 6.6 Hz, 1H, Pc–H-8*), 3.1–2.6 (m,
H, CH2), 2.25–2.05 (m, 2H, CH2), 1.82 (ddd,
C-1, C-2, C-9, C-10), 25.7 (Me) ppm; FTIR (KBr)
5
ꢀ1
m = 3368, 2928, 1594, 1500, 842, 716 cm ; EI-MS m/s (rel-
1
3
J = 14.1 Hz, 9.5 Hz, 5.2 Hz, 1H, CH ) ppm; C NMR
2
+
þ
ative intensity) 251 (24) [M ], 236 (100) ½M ꢀ CH ꢁ, 147
3
(
1
(
(
3
62.5 MHz, CDCl ): d = 187.2 (CO), 155.5 (q), 145.2 (q),
3
45.1 (q), 144.1 (q), 143.0 (q), 140.2 (q), 139.3 (q), 138.6
t), 137.7 (q), 133.8 (t), 132.4 (t), 131.9 (t), 130.9 (t), 129.5
t), 128.9 (t), 128.0 (t), 127.8 (t), 127.7 (t), 36.0, 34.9,
þ
þ
8
(
25) ½M ꢀ C H ꢁ, 104 (28) ½C H ꢁ; HRMS (m/z)
8
8
8
C H N: calc. 251.1674, found 251.1677.
1
8
21
3.20. X-Ray structure analysis of (20)
3.9, 29.5 (Pc–C-1, C-2, C-9, C-10) ppm; FTIR (KBr)
ꢀ
1
m = 2925, 1742, 1606, 1479, 844, 804 cm ; EI-MS m/z (rel-
C H O : colorless crystals, crystal dimension 0.05 ·
+
+
24 24
2
ative intensity) 388 (10) [M ], 283 (84) [M ꢀ C H ], 104
8
9
3
0
.05 · 0.40 mm ; M = 344.43; rhombohedral, space group
þ
(
100) ½C
8
H ꢁ.
8
˚
R-3 (No. 148), a = 18.0598(3) A, a = 116.341(1)ꢁ, V =
3
ꢀ1
˚
2
853.23(8) A , Z = 6, l(MoKa) = 0.075 mm , T = 123(2)
3
.19. 1-[2.2]Paracyclophan-4-yl-ethylamine (24)
K, F(000) = 1104.25552 reflection up to 2hmax = 50ꢁ were
measured on a Nonius KappaCCD diffractometer with
MoKa radiation, 3346 of which were independent and used
for all calculations. The structure was solved by direct
A sealable tube was charged with 23 (125 mg,
0
.500 mmol), ammonia (2 M in ethanol, 1.25 ml, 2.5 mmol)
2
and Ti(OiPr) (284 mg, 1.00 mmol). The vial was sealed
methods and refined to F anisotropically, the H atoms
4
afterwards. The sealed tube was evacuated and refilled with
argon. This procedure was repeated three times. The solu-
tion was heated to 50 ꢁC and was stirred for 6 h. The solu-
tion was cooled down to 0 ꢁC and NaBH4 (28 mg,
were refined with a riding model (H(O) free). The final
2
quality coefficient wR (F ) for all data was 0.2082, with a
2
conventional R(F) = 0.0634 for 241 parameters and 2
restraint. Crystallographic data (excluding structure fac-
tors) for the structures reported in this paper have been
deposited with the Cambridge Crystallographic Data
Centre as supplementary publication no. CCDC-282766
(20). Copies of the data can be obtained free of charge at
www.ccdc.cam.ac.uk/conts/retrieving.html [or from the
Cambridge Crystallographic Data Centre, 12, Union
Road, Cambrigde CB2 1EZ, UK; Fax: +44 1223/336
033; e-mail: deposit@ccdc.cam.ac.uk].
0
.75 mmol) was added and the reaction mixture was stirred
for another 3 h. The solution was combined with a 2-M
aqueous solution of NH OH and a white solid precipitated.
4
The precipitate was then filtered and washed with dichloro-
methane. The organic layer was separated and was
extracted three times with 1 M hydrochloric acid. The com-
bined aqueous layers were basified with NaOH and
extracted thrice with dichloromethane yielding 83 mg

M. Kreis et al. / Journal of Organometallic Chemistry 691 (2006) 2171–2181
2181
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