Amination of aromatic olefins with anilines: A new domino synthesis of quinolines

Article abstract of DOI:10.1002/1521-3765(20000717)6:14<2513::AID-CHEM2513>3.0.CO;2-V

A new catalytic amination of aromatic olefins with anilines is presented. In a domino reaction, substituted quinoline derivatives are obtained in the presence of cationic rhodium complexes, such as [Rh(cod)₂]BF₄, and PPh₃. Ethylbenzene is formed as a by-product in this new oxidative reaction. The first transition metal catalyzed anti-Markovnikov hydroamination of styrene with anilines occurs as a side reaction. Mechanistic investigations strongly support the regioselective oxidative amination of styrene as the key reaction step.

Full text of DOI:10.1002/1521-3765(20000717)6:14<2513::AID-CHEM2513>3.0.CO;2-V

FULL PAPER
Part 7: Anti-Markovnikov Functionalizations of Unsaturated Compounds[=]
Amination of Aromatic Olefins with Anilines:
A New Domino Synthesis of Quinolines
[b]
[a]
Matthias Beller,*[a] Oliver R.Thiel, Harald Trauthwein,[b] and Christian G.Hartung
Dedicated to Professor Dr. Hartmut Oehme on the occasion of his 60th birthday
Abstract: A new catalytic amination of aromatic olefins withanilines is presented. In
a domino reaction, substituted quinoline derivatives are obtained in the presence of
Keywords: anti-Markovnikov ami-
nations ´ domino reactions ´ homo-
cationic rhodium complexes, such as [Rh(cod)2]BF4, and PPh3. Ethylbenzene is
formed as a by-product in this new oxidative reaction. The first transition metal
catalyzed anti-Markovnikov hydroamination of styrene with anilines occurs as a side
reaction. Mechanistic investigations strongly support the regioselective oxidative
amination of styrene as the key reaction step.
geneous catalysis
rhodium
´ quinolines ´
Introduction
The development of new methods for the synthesis of amines
and nitrogen heterocycles is of fundamental importance in
organic chemistry. In general, the direct amination of readily
available olefins constitutes the most atom efficient way for
À
the construction of carbon nitrogen bonds in these products.
Considerable efforts have been undertaken to develop
Scheme 1. Regioselective aminations of allylaniline derivatives.
catalytic amination processes.[2] So far amination of olefins
has focussed mainly on the synthesis of simple amines and not
on the synthesis of heterocycles. Pioneering work on the
synthesis of heterocycles by amination of olefins was done by
Hegedus et al, who used palladium complexes for the intra-
molecular oxidative amination of 2-aminostyrene derivatives,
which led to N-heterocycles.[3] This work was continued by
Larock et al, who showed that the intramolecular amination
of allylanilines leads to 2,3-dihydroindoles or dihydroquino-
lines, according to the nature of the palladium catalyst
(Scheme 1).[4]
Recently, Marks and co-workers have developed lantha-
nide catalysts for the hydroamination of olefins.[5] Lately, this
À
À
methodology has been used for tandem C N and C C bond-
forming processes, and this yields products with pyrrolizidine,
indolizidine, pyrrole, and pyrazine skeletons.[6] Our approach
to the catalytic amination of olefins[7] was based on the use of
cationic rhodium complexes in order to enhance the reactivity
of the known rhodium halide catalysts. Indeed, in the
‡
À
presence of catalytic amounts of [Rh(cod)2] BF4 /2PPh3,
styrenes react withsecondary amines to yield linear N-(2-
arylethenyl)amines (Scheme 2).
[a] Prof. Dr. M. Beller, Dipl.-Chem. C. G. Hartung
Institut für Organische Katalyseforschung (IfOK)
an der Universität Rostock e.V., Buchbinderstrasse 5 ± 6
18055 Rostock (Germany)
Fax : (‡49)381-46693-24
Scheme 2. Rhodium-catalyzed oxidative anti-Markovnikov amination of
styrenes.
E-mail: matthias.beller@ifok.uni-rostock.de
[b] Dipl.-Chem. O. R. Thiel, Dr. H. Trauthwein
Anorganisch-chemisches Institut
Technische Universität München, Lichtenbergstrasse 4
85747 Garching (Germany)
[=] For Part 6: see ref. [1]
In this paper, we describe the rhodium-catalyzed amination
of styrenes withanilines that gives direct access to substituted
quinolines produced in a new domino reaction.[8] Quinolines
Chem. Eur. J. 2000, 6, No. 14
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M. Beller et al.
FULL PAPER
are of importance as components of biologically active
compounds, for example, the natural product quinine,[9] as
well as synthetic pharmaceuticals, for example, primaquinine,
chloroquine, and the antibacterial cloxyquine, which display
anti-malaria activity.[10, 11] The synthesis of quinolines has been
a focus of organic chemistry for more than 100 years. Classical
routes for the synthesis of quinolines, such as the Skraup,
Doebner± von Miller, Conrad ± Limbach, Combes, Friedländ-
er, and Pfitzinger quinoline syntheses,[12] mostly involve
reactions of amines withcarbonyl groups. Unfortunately,
these routes are limited to certain substitution patterns, and
due to the need for harsh reaction conditions, the yields
obtained are low in most cases. A new approachwas reported
by Povarov et al, who utilized hetero-Diels ± Alder reactions
for the formation of quinoline derivatives for the first
time.[13, 14]
Scheme 3. Rhodium-catalyzed reaction of aniline with styrene.
ideneaniline withstyrene followed by deyhdrogenation.
Apart from 2-benzyl-3-phenylquinoline, whose structure was
1
unambiguously determined by the H NMR spectrum shown
in Figure 1, no other substituted quinoline derivatives could
be isolated.
Results
As a side reaction the anti-Markovnikov hydroamination of
styrene yields N-(2-phenylethyl)aniline (1b) in 9% yield. In
addition, the formation of ethylbenzene was detected. In
order to increase the product yield of 1a, we studied this new
reaction under various conditions. The optimal reaction
Domino reactions for the synthesis of quinoline derivatives:
We have shown that cationic rhodium complexes catalyze the
intermolecular oxidative amination of secondary amines and
aromatic olefins to give terminal enamines.[7] Withthe use of
primary amines as starting materi-
als, the resulting enamines should
tautomerize to the more stable
imines. When aniline is used as the
amine in the reaction with sty-
renes, the resulting imine, phenyl-
ethylideneaniline, provides a re-
active intermediate, which can
react witha furtehr olefin in a
formal hetero-Diels ± Alder reac-
tion. In fact, when we reacted
aniline withstyrene in the pres-
ence of the cationic rhodium com-
plex [Rh(cod)2]BF4 (2.5 mol%)
and PPh3 (10 mol%) in a pressure
tube, we obtained 2-benzyl-3-
phenylquinoline (1a) in 20%
yield (Scheme 3). Clearly, 1a re-
sults from a formal hetero-Diels ±
Alder reaction of phenylethyl-
Figure 1. 1H NMR spectrum of 2-benzyl-3-phenylquinoline (1a).
temperature was 1408C in toluene. Lower yields of 1a were
obtained, when the reaction temperature was decreased to
1208C or raised to 1608C. Because of the relatively high
reaction temperature, four equivalents of PPh3 are needed for
sufficient stabilization of the rhodium center. A broad
number of solvents were tested for the reaction. Toluene,
tetrahydrofuran, and di-n-butylether gave comparable yields
of 1a, whereas lower yields were obtained with dioxane,
xylene, anisole, and N-methylpyrrolidone. Strongly coordi-
nating solvents like diglyme or butyronitrile inhibit the
reaction completely. Interestingly, the reaction could be
performed with styrene as the solvent, but the formation of
polystyrene leads to complications in the isolation of 1a.
Abstract in German: Eine neue katalytische Aminierungsre-
aktion von aromatischen Olefinen mit Anilinen wird beschrie-
ben. Unter Einsatz von kationischen Rhodiumkomplexen wie
[Rh(cod)2]BF4 /4PPh3 werden dabei direkt substituierte Chi-
nolinderivate in einer Dominoreaktion erhalten. Als Neben-
produkt dieser neuen oxidativen Reaktion wird Ethylbenzol
gebildet. Die erste übergangsmetallkatalysierte anti-Markow-
nikow-Hydroaminierung von Styrol mit Anilin findet als
Nebenreaktion statt. Mechanistische Untersuchungen dienen
als Grundlage für einen Vorschlag zum Reaktionsablauf der
Reaktion, der eine oxidative Aminierung von Styrol als
Schlüsselschritt enthält.
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Chem. Eur. J. 2000, 6, No. 14

Amination of Aromatic Olefins
2513±2522
Table 1. Rhodium-catalyzed reaction of styrene with aniline.[a]
yield [%][b]
styrene/aniline
[Rh(cod)2]BF4 [mol%]
PPh3 [mol%]
additive [mol%]
quinoline (1a)
ethylbenzene
alkylamine (1b)
1
2
3
4
5
6
7
8
9
5:1
1:1
10:1
5:1
5:1
5:1
5:1
5:1
5:1
5:1
5:1
2.5
2.5
2.5
10
10
10
10
40
40
20
4
10
10
10
10
±
±
±
±
±
±
±
20
11
18
40
43
28
10
89
34
99
134
155
107
54
13
27
27
< 0.1
9
7
9
8
6
9
5
3
4
10[c]
5
1
2.5
2.5
2.5
2.5
1a (20)
21 (ˆ20 ‡ 1)
quinoline (25)
DIPEA[d] (10)
HBF4 ´ OEt2 (20)
6
3
10
11
5
< 0.1
< 0.1
[a] [Rh(cod)2]BF4, PPh3, and additives relative to aniline, 5 mL toluene, 1408C, 20 hreaction time in a pressure tube. The yields are relative to aniline and
were determined by gas chromatography with hexadecane as an internal standard. [b] Yields refer to aniline. [c] 48 h Reaction time. [d] DIPEA
(diisopropylethylamine).
In order to investigate the influence of further reaction
parameters, the stoichiometry of the reactants, the catalyst
concentration, and additives were varied (Table 1). On
analysis of the stoichiometry of the reaction, an optimal
styrene/aniline ratio of 5:1 is expected, as two molecules of
styrene are reduced to ethylbenzene when the aromatic
quinoline system is formed. Indeed, the best results were
obtained when a styrene/aniline ratio of 5:1 was used. At
higher ratios, polystyrene is formed in significant amounts,
and product isolation becomes difficult. Furthermore, the
concentration of the reaction mixture is of great importance.
A concentration of 1m aniline is optimal, whereas the reaction
is very slow at lower concentrations. Despite considerable
optimization, product yields (1a) above 25% were not
realized witha catalyst amount of 2.5 mol%. Since N-
heterocycles are known to act as strong coordinating ligands
at the rhodium center,[15] we assumed that inhibition of the
catalyst by the reaction products occurred. To prove this
hypothesis 20 mol% of 2-benzyl-3-phenylquinoline (1a) was
added to a reaction mixture at the beginning, and this resulted
in a nearly complete deactivation of the catalyst. A similar
result was obtained when we added 25 mol% quinoline to the
reaction mixture.
In order to overcome the product inhibition, the use of a co-
catalyst was tested in the reaction. We tried to influence the
complexation behavior of the quinoline derivatives by the
addition of small amounts of an inert acid or base (Table 1).
However, a completely distinct reaction pathway was ob-
served when HBF4 ´ OEt2 was added as an acid, and the
Markovnikov N-alkylation and ortho-C alkylation products of
aniline were isolated.[16] Nevertheless, the product yield of 1a
can be increased by simply increasing the catalyst concen-
tration. Thus, when the catalyst concentration was raised to
10 mol% [Rh(cod)2]BF4/4PPh3, 1a was obtained in 43%
yield.
Table 2. Scope and limitations of the new domino quinoline synthesis.[a]
yield [%][b]
quinoline ethyl-
aniline
styrene
alkylamine
1 ± 14a
benzene 1 ± 14b
1
2
3
4
5
6
7
8
9
R1 ˆ H
R2 ˆ H
43 (40)
42 (39)
24 (19)
30 (26)
51 (48)
32 (31)
33 (31)
40 (35)
40 (36)
27 (23)
45 (44)
17 (16)
155
138
139
115
163
126
141
144
129
178
159
133
177
96
6
7
7
R1 ˆ 4-MeO R2 ˆ H
R1 ˆ 3-MeO R2 ˆ H
R1 ˆ 4-F
R1 ˆ 3-F
R1 ˆ 4-PhR
R1 ˆ 4-Me
R1 ˆ H
R2 ˆ H
R2 ˆ H
12
11
10
10
5
10
15
6
2
ˆ H
R2 ˆ H
R2 ˆ 4-F
R1 ˆ H
R2 ˆ 4-MeO
R2 ˆ 3,4-MeO
R2 ˆ 4-Me
R2 ˆ 3-CF3
10 R1 ˆ H
11 R1 ˆ H
12 R1 ˆ H
13 R1 ˆ H
14 R1 ˆ 3-F
15
12
20
2-vinylnaphthalene 35 (29)
R2 ˆ 4-Me
15 (13)
[a] Styrene:aniline 5:1, 10 mol% [Rh(cod)2]BF4/4PPh3 relative to the
amine, 5 mL toluene, 1408C, 48 hreaction time in a pressure tube. The
yields are relative to the amine and were determined by gas chromatog-
raphy with hexadecane as an internal standard; isolated yields for
compounds 1a ± 14a are added in brackets. [b] Yields refer to the aniline.
Interestingly, the reaction of both para- and meta-substi-
tuted anilines leads regioselectively to the corresponding
quinoline derivative, substituted in 6- or 7-position, respec-
tively. No clear trend is observed withregard to teh
substituent influences in boththe aniline or styrene rings. If
a catalyst concentration of 10 mol% is used, in general, yields
of 30 ± 50% of the corresponding tri- or tetrasubstituted
quinolines are obtained.
Next, we were interested in the application of the reaction
to various aniline and styrene derivatives, and these results are
summarized in Table 2. Except for the reaction of 3-fluoroani-
line and 4-methylstyrene (Table 2, entry 14), the anti-Mar-
kovnikov hydroamination of styrene is a side reaction path-
way, and hydroamination products in yields of 5 ± 15% are
obtained.
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M. Beller et al.
FULL PAPER
Mechanistic investigations: In order to shed some light on the
mechanism of the domino reaction of styrene and aniline, the
time-dependent conversion of the starting materials together
with the product formation was studied. For this purpose, a
reaction mixture of styrene and aniline in a ratio of 5:1,
5 mol% [Rh(cod)2]BF4/4PPh3 (relative to aniline), and tol-
uene as the solvent was equally distributed among eleven
pressure tubes and heated to 1408C. After a given reaction
time, one of the pressure tubes was rapidly cooled to room
temperature to stop any further reaction. The data obtained
are shown in Figure 2.
aniline with phenylacetaldehyde. Surprisingly, the imine or
enamine could not be isolated, instead 2-benzyl-3-phenyl-
quinoline (1a) was formed in 29% yield (Scheme 4).
The conversion of aniline and styrene is nearly parallel in
the first 30 hours, however later on, only styrene is consumed,
and polystyrene is formed. On the other hand, after 20 hours
no further significant formation of 1a and 1b is observed. The
formation of 1a parallels the formation of ethylbenzene with a
constant ratio of 1:4. In a stoichiometric reaction, only three
equivalents of ethylbenzene should be formed per equivalent
of quinoline. Hence, other oxidative side reactions that lead to
oligomerization and polymerization products must also be
considered. The main reaction products 1a and 1b are formed
by independent pathways, no consecutive or decomposition
reactions are involved. The first ten hours of the reaction are
particularly interesting. A clear induction period was ob-
served with the maximum rate of conversion after 1 hour.
After this period, the reaction is slowed down as a result of the
product inhibition of the catalyst. The induction period is
explained by the slow formation of the active rhodium
catalyst. Interestingly, [Rh(cod)(PPh3)2]BF4 was isolated out
of the reaction mixture in the form of orange crystals after a
reaction time of 1 hour. However, this complex must also be a
precursor of the active species, because of the lack of any
styrene or aniline ligand. No other defined rhodium com-
plexes could be isolated out of the reaction mixture after
longer reaction times.
Scheme 4. Condensation of phenylacetaldehyde with aniline.
This condensation experiment showed that the presence of
styrene is not a prerequisite for the formation of 2-benzyl-3-
phenylquinoline (1a). We propose instead that the formation
of the quinoline ring takes place by an attack of the enamine
on the tautomeric imine followed by an electrophilic sub-
stitution in the ortho-position of the imine intermediate. This
proposal is in agreement withthe recently described con-
densation of aniline hydrochloride with phenylacetaldehyde
in the presence of the reducing agent NaBH3CN that leads to
1,2,3,4-tetrahydro-2-benzyl-3-phenylquinoline.[17]
Nevertheless, the reactivity of styrene in an aza-Diels ±
Alder reaction witha stable imine ( N-benzylideneaniline) in
the presence of a rhodium catalyst (2.5 mol% [Rh(cod)2]BF4/
2PPh3) was tested. In the reaction, 2,4-diphenylquinoline was
formed in 21% yield (Scheme 5). In addition, the imine is
reduced instead of the styrene in this case, and no ethyl-
benzene is formed in the reaction. The observed 2,4-substi-
Based on our previous work, we proposed N-(2-phenyl-
ethenyl)aniline as the primary reaction intermediate of the
domino reaction, which will tautomerize to the thermody-
namically more stable N-(2-phenylethylidene)aniline. In or-
der to study the following reaction steps, we tried to
synthesize N-(2-phenylethylidene)aniline by condensation of
tution pattern of the quinoline derivative is in good agreement
[14]
withother catalyzed aza-Diels ± Alder reactions,
and this
shows that the 2,3-regiochemistry of the reported domino
quinoline reaction can be ascribed to the reaction of N-(2-
phenylethenyl)aniline with N-phenyl-N-phenylethylimine as
dienophile instead of styrene.
Figure 2. Time ± yield diagram of the rhodium-catalyzed reaction of styrene with aniline.
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Amination of Aromatic Olefins
2513±2522
Scheme 7. Mechanism proposed by Diamond, Mares et al.
seem very likely for the formation of 2-benzyl-3-arylquino-
line. Based on the results for the formation of the anti-
Markovnikov hydroamination product and the model reac-
tion of phenylacetaldehyde with aniline, we propose the
following mechanism (Scheme 8).
Scheme 5. aza-Diels ± Alder reaction of styrene with N-benzylideneani-
line.
Discussion
The rhodium-catalyzed domino reaction of styrene and
aniline constitutes one of the very few amination reactions
of olefins that provides access to heterocycles. As it starts
from easily available reagents, this new reaction permits the
direct synthesis of a variety of different di-, tri-, and
tetrasubstituted quinolines. However, it is clear that this
new reaction needs to be improved in order to be useful as a
broad preparative method.
Interestingly, some time ago Brunet and co-workers
demonstrated that a catalyst system of lithium anilide and
rhodium bis(triethylphosphine)chloride [Rh(PEt3)2Cl]2 led to
a totally different outcome for the same reaction. In this case,
both the oxidative amination and the hydroamination of
[18]
styrene is observed withMarkovnikov regioselectivity.
In 1979, Diamond and Mares et al. reported that the
reaction of ethylene and aniline in the presence of RhCl3 leads
to the formation of 2-methylquinoline in 2.5% yield
(Scheme 6).[19]
Scheme 8. Mechanism for the domino reaction of aniline with styrene.
The oxidative product N-(2-phenylethenyl)aniline 16,
which is intially formed, is in equilibrium with the corre-
sponding imine N-(2-phenylethylidene)aniline 17. Th
imine 17 reacts withthe enamine 16 in a formal aza-Diels ±
Alder reaction. Similar aza-Diels ± Alder reactions withsub-
stituted N-benzylideneanilines have been described in the
literature.[13, 14, 20, 21] Mechanistic studies for this type of
reaction have excluded a concerted [4‡2] cycloaddition, and
a stepwise mechanism has been proposed instead.[14f, 20b]
Hence, we propose an attack of the enamine on the
tautomeric imine followed by an electrophilic substitution in
the ortho-position of the iminium intermediate 18. Aniline is
eliminated readily under the reaction conditions, and the
dihydroquinoline 20 is formed. The oxidation to the aromatic
system 1a is performed by hydrogen transfer to styrene.
The comparison of the quinoline yields with different
substituted anilines shows that the cyclization step is of great
e
Scheme 6. Rhodium-catalyzed reaction of aniline with ethylene.
They postulated a mechanism (Scheme 7) for the formation
of 2-methylquinoline that includes an ortho-metallation of
aniline and subsequent ethylene insertion. After the second
ethylene insertion step, a transfer hydrogenation would lead
to an alkene ± amine ± rhodium complex, which could react in
an intramolecular hydroamination reaction. Further hydro-
gen transfer to ethylene would yield 2-methylquinoline.
On consideration of our results for the rhodium-catalyzed
oxidative amination of aromatic olefins withsecondary
amines as well as the results obtained in this work, the
mechanistic proposal of Diamond and Mares et al. does not
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M. Beller et al.
FULL PAPER
formed. The solution cleared slightly during addition of the aromatic amine
(2.2 mmol). Afterwards the aromatic olefin (11 mmol) and hexadecane
(100 mL) were added. The reaction vessel was closed cautiously and placed
in an oil bath(140 8C). The reaction mixture was stirred for 48 h, and a
brown to black solution was produced. The solvent was evaporated in
vacuo. The crude product was separated by column chromatography with a
given eluent.
influence. If 3-fluoroaniline is used, the cyclization occurs
para to the fluoro substituent, whereas the ring closure with
4-fluoroaniline proceeds meta to the fluoro atom, although
this should be disfavored. In agreement with this assumption,
the yield of 4a is lower compared with 5a. In the case of
substituted anisidines, the oxidative amination seems to
determine the product yield. The more basic amine (4-
anisidine) gives a better yield of 2a compared with 3a. Th e
low yield of 6a with4-aminobiphenyl is explained by steric
hinderance during the ring closure.
2-Benzyl-3-phenylquinoline (1a): According to the general procedure,
aniline (0.20 mL, 2.2 mmol) was treated withstyrene (1.26 mL, 11 mmol).
After purification by column chromatography (hexane/ethylacetate 10:1),
1a was obtained as a yellow oil. Compound 1b was isolated as the by-
product. Yield of 1a: 43% (GC); 260 mg, 40% (isolated); 1H NMR
(400 MHz, 258C, CDCl3, TMS): d ˆ 8.08 (d, 3J(H,H) ˆ 8.0 Hz, 1H; CH),
3
3
7.84 (s, 1H; CH), 7.67 (d, J(H,H) ˆ 8.0 Hz, 1H; CH), 7.61 (dd, J(H,H) ˆ
8.0, 3J(H,H) ˆ 7.0 Hz, 1H; CH), 7.41 (dd, 3J(H,H) ˆ 8.0, 3J(H,H) ˆ 7.0 Hz,
1H; CH), 7.28 ± 7.26 (m, 2H; CH), 7.10 ± 7.07 (m, 2H; CH), 7.02 ± 6.98 (m,
4H; CH), 6.86 ± 6.83 (m, 2H; CH), 4.25 (s, 2H; CH2); 13C NMR (101 MHz,
258C, CDCl3, TMS): d ˆ 159.5, 147.5, 139.9, 139.6, 137.4, 136.5, 129.9, 129.8,
129.3, 129.2, 128.6, 128.5, 128.0, 127.9, 127.3, 126.8, 126.3, 43.2; MS (70 eV,
Conclusion
The rhodium-catalyzed amination of styrenes with anilines
leads to the direct formation of substituted quinolines in
yields of 30 ± 50%; the yields mainly depend on the catalyst
‡
‡
‡
EI): m/z (%): 294 [M À H], 218 [M À C6H5], 204 [M À CH2 À C6H5], 189,
176, 146, 134, 108, 91, 77; C22H17N (295.38): calcd C 89.46, H 5.80, N 4.74;
found C 89.38, H 6.12, N 4.43.
À
concentration. During the course of the reaction, one C N
À
and two C C bonds are formed, and six hydrogen atoms
N-(2-Phenylethyl)aniline (1b): Yield of 1b: 6% (GC); 1H NMR (400 MHz,
258C, CDCl3, TMS): d ˆ 7.34 ± 7.15 (m, 7H; CH), 6.71 (t, 3J(H,H) ˆ 7.0 Hz,
1H; CH), 6.62 (d, 3J(H,H) ˆ 8.1 Hz, 2H; CH), 3.69 (s, 1H; NH), 3.42 (t,
3J(H,H) ˆ 7.0 Hz, 2 H ; CH2), 2.93 (t, 3J(H,H) ˆ 7.0 Hz, 2H; CH2); 13C NMR
(101 MHz, 258C, CDCl3, TMS): d ˆ 148.0, 139.3, 129.4, 128.8, 128.6, 126.4,
are transferred. This new domino reaction represents one
of the rare cases in heterocycle synthesis that involves an
in situ amination of olefins. During the course of the reac-
tion, styrene serves as the oxidizing agent and forms
ethylbenzene. Side products N-(2-arylethyl)anilines are ob-
tained, which result formally from the transition metal
catalyzed anti-Markovnikov hydroamination of styrene with
aniline.
‡
‡
117.4, 113.0, 45.0, 35.5; MS (70 eV, EI): m/z (%): 197 [M ], 106 [M À
CH2 À C6H5], 91, 77, 65.
2-Benzyl-3-phenyl-6-methoxyquinoline (2a): According to the general
procedure, 4-anisidine (271 mg, 2.2 mmol) was treated withstyrene
(1.26 mL, 11 mmol). After purification by column chromatography (hex-
ane/ethylacetate 20:1), 2a was obtained as an orange oil. Compound 2b
was isolated as the by-product. Yield of 2a: 42% (GC); 279 mg, 39%
(isolated); 1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 8.00 (d,
3J(H,H) ˆ 8.9 Hz, 1H; CH), 7.74 (s, 1H; CH), 7.25 ± 7.21 (m, 2H; CH),
7.17 (d, 3J(H,H) ˆ 8.9 Hz, 1H; CH), 7.11 (s, 1H; CH), 7.05 ± 7.03 (m, 2H;
CH), 6.97 ± 6.91 (m, 4H; CH), 6.79 (d, 3J(H,H) ˆ 7.5 Hz, 2H; CH), 4.19 (s,
2H; CH2), 3.78 (s, 3H; CH3); 13C NMR (101 MHz, 258C, CDCl3, TMS):
d ˆ 157.8, 156.2, 139.8, 139.7, 139.6, 136.3, 136.0, 129.4, 129.3, 128.8, 128.2,
128.0, 127.9, 127.6, 125.8, 114.9, 112.5, 55.5, 42.8; MS (70 eV, EI): m/z (%):
Although it is clear that the reaction is not yet a complete
preparative method for the synthesis of quinolines, the
presented study offers interesting new aspects in the field of
catalytic amination of unsaturated compounds to yield
heterocycles. Further studies to enhance the yield of the
products by means of an increase in catalyst concentration as
well as the use of an additional partner for the ªformalº
Diels ± Alder reaction are in progress.
‡
‡
‡
324 [M À H], 310 [M À CH3], 281, 248 [M À C6H5], 232, 204, 191, 163,
139, 91, 77; C23H19NO (325.41): calcd C 84.89, H 5.88, N 4.30; found C 84.69,
H 6.03, N 4.35.
N-(2-Phenylethyl)-(4-methoxy)aniline (2b): Yield of 2b: 7% (GC);
1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 7.39 ± 7.13 (m, 5H; CH),
6.77 (d, 3J(H,H) ˆ 8.8 Hz, 2H; CH), 6.53 (d, 3J(H,H) ˆ 8.8 Hz, 2H; CH),
3.76 (s, 3H; CH3), 3.71 (s, 1H; NH), 3.39 (t, 3J(H,H) ˆ 7.1 Hz, 2H; CH2),
2.95 (t, 3J(H,H) ˆ 7.1 Hz, 2H; CH2); 13C NMR (101 MHz, 258C, CDCl3,
TMS): d ˆ 148.6, 142.0, 139.2, 128.7, 128.3, 127.9, 114.9, 114.5, 55.7, 46.5,
Experimental Section
Materials and methods: All reactions withorganometallic compounds
were carried out with the use of vacuum line, Schlenk, and syringe
techniques. The catalytic reactions were carried out in Ace pressure tubes
(purchased from Aldrich). Warning: the required safety measures should
be taken when performing reactions under pressure. All solvents were
dried and distilled prior to use, according to standard procedures. Amines
were distilled from CaH2, and silver salts and other chemicals were
‡
‡
35.8; MS (70 eV, EI): m/z (%): 227 [M ], 162, 136 [M À CH2 À C6H5], 108,
91, 77, 65.
2-Benzyl-3-phenyl-7-methoxyquinoline (3a): According to the general
procedure, 3-anisidine (0.25 mL, 2.2 mmol) was treated withstyrene
(1.26 mL, 11 mmol). After purification by column chromatography (hex-
ane/ethylacetate 20:1), 3a was obtained as an orange oil. Compound 3b
was isolated as the by-product. Yield of 3a: 24% (GC); 136 mg, 19%
(isolated); 1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 7.77 (s, 1H; CH),
7.54 (d, 3J(H,H) ˆ 8.8 Hz, 1H; CH), 7.40 (d, 4J(H,H) ˆ 2.2 Hz, 1H; CH),
7.25 ± 7.23 (m, 2H; CH), 7.12 ± 6.98 (m, 7H; CH), 6.84 (dd, 3J(H,H) ˆ 7.4,
4J(H,H) ˆ 1.5 Hz, 2H; CH), 4.20 (s, 2H; CH2), 3.86 (s, 3H; CH3); 13C NMR
(101 MHz, 258C, CDCl3, TMS): d ˆ 160.8, 159.0, 148.3, 139.6, 139.3, 136.8,
133.9, 129.5, 128.8, 128.4, 128.1, 128.0, 127.4, 125.8, 122.0, 119.6, 106.7, 55.6,
[22]
purchased from Fluka and Aldrich and used as received. [Rh(cod)Cl]2
[23]
and [Rh(cod)2]BF4
were prepared as described in the appropriate
reference. N-benzylideneaniline[24] was prepared according to a literature
procedure.
1
Physical and analytical methods: H and 13C NMR spectra were recorded
on a JEOL-GX400 spectrometer (1H: 399.80 MHz; 13C: 100.53 MHz). H
1
and 13C chemical shifts have been reported in d relative to tetramethylsi-
lane. The elemental analyses were carried out by the Microanalytical
Laboratory of the Technische Universität München. GC spectra for
analysis of catalytic reactions were recorded on a HP6890 gas chromato-
graphwitha HP1 capillary column. Yields were determined with
hexadecane as the internal standard. GC/MS studies were conducted on
a HP5890 withEI electron impact ionization (detector: HP5970B, 70 eV).
‡
‡
42.5; MS (70 eV, EI): m/z (%): 324 [M À H], 310 [M À CH3], 281, 248
‡
[M À C6H5], 232, 204, 191, 163, 139, 102, 91; C23H19NO (325.41): calcd C
84.89, H 5.88, N 4.30; found C 84.74, H 6.18, N 4.15.
General procedure for the synthesis of substituted quinolines by a domino
reaction: [Rh(cod)2]BF4 (90 mg, 0.22 mmol) and PPh3 (232 mg, 0.88 mmol)
were suspended in a pressure tube (15 mL) in toluene (2.5 mL) under an
argon atmosphere. A dark yellow solution and an orange precipitate were
N-(2-Phenylethyl)-(3-methoxy)aniline (3b): Yield of 3b: 7% (GC);
1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 7.36 ± 7.08 (m, 6H; CH),
6.31 (m, 1H; CH), 6.29 (m, 1H; CH), 6.21 (dd, 4J(H,H) ˆ 2.3, 4J(H,H) ˆ
3
2.2 Hz, 1H; CH), 3.82 (s, 1H; NH), 3.79 (s, 3H; CH3), 3.42 (t, J(H,H) ˆ
2518
ꢀ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000
0947-6539/00/0614-2518 $ 17.50+.50/0
Chem. Eur. J. 2000, 6, No. 14

Amination of Aromatic Olefins
2513±2522
7.0 Hz, 2H; CH2), 2.94 (t, 3J(H,H) ˆ 7.0 Hz, 2H; CH2); 13C NMR
(101 MHz, 258C, CDCl3, TMS): d ˆ 160.8, 149.1, 138.5, 129.9, 128.8,
128.6, 126.4, 106.2, 102.7, 99.0, 55.0, 45.1, 35.4; MS (70 eV, EI): m/z (%): 227
[M ], 136 [M À CH2 À C6H5], 91, 77.
N-(2-Phenylethyl)-(4-phenyl)aniline (6b): Yield of 6b: 10% (GC); MS
‡
‡
(70 eV, EI): m/z (%): 273 [M ], 207, 182 [M À CH2 À C6H5], 152, 133, 110,
96.
‡
‡
2-Benzyl-3-phenyl-6-methylquinoline (7a): According to the general
procedure, 4-toluidine (236 mg, 2.2 mmol) was treated withstyrene
(1.26 mL, 11 mmol). After purification by column chromatography (hex-
ane/ethylacetate 15:1), 7a was obtained as a yellow solid. Compound 7b
was isolated as the by-product. Yield of 7a: 33% (GC); 210 mg, 31%
(isolated); 1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 8.03 (d,
3J(H,H) ˆ 8.1 Hz, 1H; CH), 7.82 (s, 1H; CH), 7.51 (d, 3J(H,H) ˆ 8.1 Hz,
1H; CH), 7.50 (s, 1H; CH), 7.33 (m, 3H; CH), 7.16 (m, 2H; CH), 7.07 (m,
3H; CH), 6.91 (m, 2H; CH), 4.30 (s, 2H; CH2), 2.49 (s, 3H; CH3); 13C NMR
(101 MHz, 258C, CDCl3, TMS): d ˆ 158.0, 145.7, 139.7, 139.4, 136.1, 136.1,
136.0, 131.6, 129.4, 128.8, 128.6, 128.1, 127.9, 127.4, 126.9, 126.2, 125.8, 42.7,
2-Benzyl-3-phenyl-6-fluoroquinoline (4a): According to the general pro-
cedure, 4-fluoroaniline (0.21 mL, 2.2 mmol) was treated withstyrene
(1.26 mL, 11 mmol). After purification by column chromatography (hex-
ane/ethylacetate 10:1), 4a was obtained as an orange oil. Compound 4b
was isolated as the by-product. Yield of 4a: 24% (GC); 136 mg, 19%
(isolated); 1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 8.06 (dd,
4
3J(H,H) ˆ 8.6 Hz, J(H,F) ˆ 5.5 Hz, 1H; CH), 7.79 (s, 1H; CH), 7.37 (ddd,
3J(H,F) ˆ 9.0, 3J(H,H) ˆ 8.6, 4J(H,H) ˆ 3.0 Hz, 1H; CH), 7.29 ± 7.21 (m,
3H; CH), 7.11 ± 7.08 (m, 2H; CH), 7.03 ± 7.01 (m, 4H; CH), 6.84 (dd,
3J(H,H) ˆ 7.0, 4J(H,H) ˆ 2.0, 2H; CH), 4.23 (s, 2H; CH2); 13C NMR
(101 MHz, 258C, CDCl3, TMS): d ˆ 160.9 (d, 1J(C,F) ˆ 247.8 Hz), 158.9,
‡
‡
21.5; MS (70 eV, EI): m/z (%): 308 [M À H], 232 [M À C6H5], 230, 217,
154, 146, 91; C23H19N (309.41): calcd C 89.28, H 6.19, N 4.53; found C 88.71,
H 6.34, N 4.95.
4
3
144.6 (d, J(C,F) ˆ 2.9 Hz), 139.6, 139.5, 136.6, 131.8 (d, J(C,F) ˆ 9.7 Hz),
3
129.8, 129.3, 128.7, 128.5, 127.9 (d, J(C,F) ˆ 9.7 Hz), 128.2, 126.4, 119.9 (d,
2J(C,F) ˆ 25.3 Hz), 110.9 (d, J(C,F) ˆ 21.4 Hz), 43.0; MS (70 eV, EI): m/z
2
N-(2-Phenylethyl)-(4-methyl)aniline (7b): Yield of 7b: 10% (GC);
1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 7.35 ± 7.20 (m, 5H; CH),
7.00 (d, 3J(H,H) ˆ 8.4 Hz, 2H; CH), 6.55 (d, 3J(H,H) ˆ 8.4 Hz, 2H; CH),
3.38 (t, 3J(H,H) ˆ 7.0 Hz, 2H; CH2), 2.91 (t, 3J(H,H) ˆ 7.0 Hz, 2H; CH2),
2.24 (s, 3H; CH3); 13C NMR (101 MHz, 258C, CDCl3, TMS): d ˆ 145.7,
139.4, 129.7, 128.8, 128.5, 128.3, 126.3, 113.2, 45.4, 35.5, 20.4; MS (70 eV, EI):
‡
‡
(%): 312 [M À H], 298, 277, 236 [M À C6H5], 207, 174, 142, 129, 105, 96;
C22H18FN (313.37): calcd C 84.32, H 5.79, N 4.46; found C 84.45, H 5.85, N
4.37.
N-(2-Phenylethyl)-(4-fluoro)aniline (4b): Yield of 4b: 12% (GC);
1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 7.30 ± 7.27 (m, 2H; CH),
7.14 ± 7.09 (m, 3H; CH), 6.79 (dd, 3J(H,F) ˆ 9.0, 3J(H,H) ˆ 8.0 Hz, 2H;
‡
‡
m/z (%): 211 [M ], 120 [M À CH2 À C6H5], 91, 77, 65.
3
CH), 6.45 ± 6.42 (m, 2H; CH), 3.42 (s, 1H; NH), 3.26 (t, J(H,H) ˆ 7.0 Hz,
2-(4-Fluorophenylmethyl)-3-(4-fluorophenyl)quinoline (8a): According to
the general procedure, aniline (0.20 mL, 2.2 mmol) was treated with
4-fluorostyrene (1.31 mL, 11 mmol). After purification by column chro-
matography (hexane/ethylacetate 10:1), 8a was obtained as a dark yellow
oil. Compound 8b was isolated as the by-product. Yield of 8a: 40% (GC);
255 mg, 35% (isolated); 1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 8.06
(d, 3J(H,H) ˆ 8.5 Hz, 1H; CH), 7.82 (s, 1H; CH), 7.67 (d, 3J(H,H) ˆ 8.0 Hz,
1H; CH), 7.62 (ddd, 3J(H,H) ˆ 8.5, 3J(H,H) ˆ 8.0, 4J(H,H) ˆ 1.6 Hz, 1H;
CH), 7.43 (ddd, 3J(H,H) ˆ 8.0, 3J(H,H) ˆ 8.0, 4J(H,H) ˆ 1.0 Hz, 1H; CH),
7.01 (dd, 3J(H,H) ˆ 8.5, 4J(H,F) ˆ 6.0 Hz, 2H; CH), 6.95 (dd, 3J(H,F) ˆ 9.0,
3J(H,H) ˆ 8.5 Hz, 2H; CH), 6.77 (dd, 3J(H,H) ˆ 8.5, 4J(H,F) ˆ 6.0 Hz, 2H;
CH), 6.69 (dd, 3J(H,F) ˆ 9.0, 3J(H,H) ˆ 8.5 Hz, 2H; CH), 4.18 (s, 2H;
CH2); 13C NMR (101 MHz, 258C, CDCl3, TMS): d ˆ 161.4 (d, 1J(C,F) ˆ
246.9 Hz), 160.3 (d, 1J(C,F) ˆ 243.9 Hz), 157.8, 145.9, 136.3, 134.2 (d,
4J(C,F) ˆ 3.9 Hz), 133.9, 133.5 (d, 4J(C,F) ˆ 2.9 Hz), 130.0 (d, 3J(C,F) ˆ
7.8 Hz), 129.1 (d, 3J(C,F) ˆ 7.8 Hz), 128.7, 127.7, 126.4, 125.8, 125.6, 114.1
(d, 2J(C,F) ˆ 21.4 Hz), 113.8 (d, 2J(C,F) ˆ 21.4 Hz), 40.9; MS (70 eV, EI):
2H; CH2), 2.80 (t, 3J(H,H) ˆ 7.0 Hz, 2H; CH2); 13C NMR (101 MHz, 258C,
CDCl3, TMS): d ˆ 156.3 (d, 1J(C,F) ˆ 235.0 Hz), 144.7 (d, 4J(C,F) ˆ
3.0 Hz), 137.4, 129.2, 129.0, 126.9, 116.0 (d, 2J(C,F) ˆ 22.4 Hz), 114.2 (d,
‡
‡
3J(C,F) ˆ 7.8 Hz), 46.1, 35.8; MS (70 eV, EI): m/z (%): 215 [M ], 124 [M À
CH2 À C6H5], 91, 75, 65.
2-Benzyl-3-phenyl-7-fluoroquinoline (5a): According to the general pro-
cedure, 3-fluoroaniline (0.21 mL, 2.2 mmol) was treated withstyrene
(1.26 mL, 11 mmol). After purification by column chromatography (hex-
ane/ethylacetate 10:1), 5a was obtained as a pale brown oil. Compound 5b
was isolated as the by-product. Yield of 5a: 51% (GC); 331 mg, 48%
(isolated); 1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 7.81 (s, 1H; CH),
7.68 (dd, 3J(H,F) ˆ 10.0, 4J(H,H) ˆ 2.5 Hz, 1H; CH), 7.63 (dd, 3J(H,H) ˆ
9.0, 4J(H,F) ˆ 6.0 Hz, 1H; CH), 7.04 ± 7.02 (m, 1H; CH), 7.28 ± 7.26 (m, 2H;
CH), 7.11 ± 7.08 (m, 2H; CH), 7.01 ± 6.95 (m, 4H; CH), 6.86 ± 6.83 (m, 2H;
CH), 4.21 (s, 2H; CH2); 13C NMR (101 MHz, 258C, CDCl3, TMS): d ˆ
163.5 (d, 1J(C,F) ˆ 249.0 Hz), 160.7, 148.4 (d, 3J(C,F) ˆ 12.6 Hz), 139.7,
139.5, 137.2, 135.8, 130.7 (d, 3J(C,F) ˆ 9.7 Hz), 129.9, 129.3, 128.6, 128.5,
‡
‡
m/z (%): 330 [M À H], 236 [M À C6H4F], 207, 166, 133, 109, 83, 75;
C22H15F2N (331.36): calcd C 79.74, H 4.56, N 4.23; found C 79.41, H 4.89, N
4.05.
4
2
128.1, 126.5, 124.3 (d, J(C,F) ˆ 2.0 Hz), 117.2 (d, J(C,F) ˆ 25.3 Hz), 113.0
(d, 2J(C,F) ˆ 19.4 Hz), 43.1; MS (70 eV, EI): m/z (%): 312 [M À H], 234
‡
‡
[M À C6H5], 221, 207, 155, 142, 119, 91; C22H18FN (313.37): calcd C 84.32, H
N-(2-(4-Fluorophenyl)ethyl)aniline (8b): Yield of 8b: 5% (GC); 1H NMR
(400 MHz, 258C, CDCl3, TMS): d ˆ 7.25 ± 7.05 (m, 4H; CH), 6.91 ± 6.87 (m,
2H; CH), 6.62 (t, 3J(H,H) ˆ 7.5 Hz, 1H; CH), 6.52 (d, 3J(H,H) ˆ 8.4 Hz,
2H; CH), 3.60 (s, 1H; NH), 3.27 (t, 3J(H,H) ˆ 7.0 Hz, 2H; CH2), 2.78 (t,
3J(H,H) ˆ 7.0 Hz, 2 H ; CH2); 13C NMR (101 MHz, 258C, CDCl3, TMS):
d ˆ 160.6 (d, 1J(C,F) ˆ 244.9 Hz), 146.8, 133.9 (d, 4J(C,F) ˆ 2.7 Hz), 129.1
5.79, N 4.46; found C 84.03, H 6.15, N 4.34.
N-(2-Phenylethyl)-(3-fluoro)aniline (5b): Yield of 5b: 11% (GC);
1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 7.27 ± 7.16 (m, 6H; CH),
3
6.29 ± 6.04 (m, 3H; CH), 3.24 (t, J(H,H) ˆ 7.0 Hz, 2H; CH2), 3.79 (s, 1H;
NH), 2.78 (t, 3J(H,H) ˆ 7.0 Hz, 2H; CH2); 13C NMR (101 MHz, 258C,
CDCl3, TMS): d ˆ 164.6 (d, 1J(C,F) ˆ 243.0 Hz), 150.2 (d, 3J(C,F) ˆ
10.7 Hz), 139.4, 129.9, 129.3, 129.1 (d, 3J(C,F) ˆ 9.7 Hz), 128.7, 109.2 (d,
3
2
(d, J(C,F) ˆ 7.8 Hz), 128.3, 116.6, 114.3 (d, J(C,F) ˆ 21.4 Hz), 112.0, 44.1,
‡
33.6; MS (70 eV, EI): m/z (%): 215 [M ], 201, 148, 107.
2
4J(C,F) ˆ 1.9 Hz), 104.1 (d, J(C,F) ˆ 22.4 Hz), 99.9 (d, 2J(C,F) ˆ 25.3 Hz),
2-(4-Methoxyphenylmethyl)-3-(4-methoxyphenyl)quinoline (9a): Accord-
ing to the general procedure, aniline (0.20 mL, 2.2 mmol) was treated with
4-methoxystyrene (1.46 mL, 11 mmol). After purification by column
chromatography (hexane/ethylacetate 10:1), 9a was obtained as a yellow
oil. Compound 9b was isolated as the by-product. Yield of 9a: 40% (GC);
281 mg, 36% (isolated); 1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 8.06
(d, 3J(H,H) ˆ 8.1 Hz, 1H; CH), 7.81 (s, 1H; CH), 7.65 (d, 3J(H,H) ˆ 7.9 Hz,
1H; CH), 7.57 (dd, 3J(H,H) ˆ 8.1, 3J(H,H) ˆ 7.0 Hz, 1H; CH), 7.40 (dd,
3J(H,H) ˆ 7.9, 3J(H,H) ˆ 7.0 Hz, 1H; CH), 7.14 (d, 3J(H,H) ˆ 8.5 Hz, 2H;
CH), 6.74 (d, 3J(H,H) ˆ 8.6 Hz, 2H; CH), 6.58 (d, 3J(H,H) ˆ 8.5 Hz, 2H;
‡
‡
45.3, 35.7; MS (70 eV, EI): m/z (%): 215 [M ], 124 [M À CH2 À C6H5], 95,
77, 65.
2-Benzyl-3-phenyl-6-phenylquinoline (6a): According to the general
procedure, 4-aminobiphenyl (372 mg, 2.2 mmol) was treated with styrene
(1.26 mL, 11 mmol). After purification by column chromatography (hex-
ane/ethylacetate 10:1), 6a was obtained as an orange oil. By-product 6b
could not be isolated. Yield of 6a: 32% (GC); 253 mg, 31% (isolated);
1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 8.11 (d, 3J(H,H) ˆ 8.6 Hz,
1H; CH), 7.87 ± 7.83 (m, 3H; CH), 7.58 (d, 3J(H,H) ˆ 7.0 Hz, 2H; CH), 7.36
3
3
(t, J(H,H) ˆ 7.5 Hz, 1H; CH), 7.28 ± 7.24 (m, 4H; CH), 7.11 ± 7.08 (m, 2H;
CH), 6.49 (d, J(H,H) ˆ 8.6 Hz, 2H; CH), 4.20 (s, 2H; CH2), 3.73 (s, 3H;
CH), 7.01 ± 6.97 (m, 4H; CH), 6.85 (dd, 3J(H,H) ˆ 7.0, 4J(H,H) ˆ 2.0 Hz,
2H; CH), 4.24 (s, 2H; CH2); 13C NMR (101 MHz, 258C, CDCl3, TMS): d ˆ
159.6, 147.0, 140.9, 140.0, 139.8, 139.6, 137.5, 136.9, 129.9, 129.8, 129.6, 129.4,
129.3, 128.7, 128.6, 128.1, 128.0, 127.8, 127.5, 126.4, 125.6, 43.2; MS (70 eV,
CH3), 3.70 (s, 3H; CH3); 13C NMR (101 MHz, 258C, CDCl3, TMS): d ˆ
157.3, 157.2, 156.7, 143.5, 138.5, 136.7, 131.0, 129.5, 129.4, 129.2, 128.5, 128.3,
127.6, 127.0, 126.1, 113.4, 113.0, 54.2, 54.1, 42.5; MS (70 eV, EI): m/z (%): 354
‡
‡
‡
[M À H], 310, 248 [M À C6H4OCH3], 234 [M À CH2 À C6H4OCH3], 229,
176, 138, 121, 107, 77; C24H21NO2 (355.43): calcd C 81.10, H 5.96, N 3.94;
found C 80.93, H 6.31, N 3.76.
‡
EI): m/z (%): 370 [M À H], 281, 207, 168, 150, 131, 96; C28H21N (371.48):
calcd C 90.53, H 5.70, N 3.77; found C 90.50, H 5.96, N 3.39.
Chem. Eur. J. 2000, 6, No. 14
ꢀ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000
0947-6539/00/0614-2519 $ 17.50+.50/0
2519

M. Beller et al.
FULL PAPER
N-(2-(4-Methoxyphenyl)ethyl)aniline (9b): Yield of 9b: 10% (GC);
1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 7.35 ± 7.15 (m, 4H; CH),
6.90 (d, 3J(H,H) ˆ 8.4 Hz, 2H; CH), 6.79 (t, 3J(H,H) ˆ 7.5 Hz, 1H; CH),
3J(H,H) ˆ 8.1, 3J(H,H) ˆ 7.9 Hz, 1H; CH), 7.48 (t, 3J(H,H) ˆ 7.7 Hz, 1H;
CH), 7.37 ± 7.30 (m, 3H; CH), 7.20 (t, 3J(H,H) ˆ 7.7 Hz, 1H; CH), 7.10 (d,
3J(H,H) ˆ 7.7 Hz, 1H; CH), 7.05 (s, 1H; CH), 4.35 (s, 2H; CH2); 13C NMR
(101 MHz, 258C, CDCl3, TMS): d ˆ 157.7, 147.3, 140.0, 139.6, 137.3, 134.3,
132.5, 132.0, 130.9 (q, 2J(C,F) ˆ 32.4 Hz), 130.4 (q, 2J(C,F) ˆ 32.4 Hz),
130.0, 129.0, 128.8, 128.6, 127.5, 126.9, 126.8, 126.0 (q, 3J(C,F) ˆ 3.8 Hz),
3
6.70 (d, J(H,H) ˆ 7.5 Hz, 2H; CH), 3.84 (s, 3H; CH3), 3.75 (s, 1H; NH),
3.41 (t, 3J(H,H) ˆ 7.1 Hz, 2H; CH2), 2.91 (t, 3J(H,H) ˆ 7.1 Hz, 2H; CH2);
13C NMR (101 MHz, 258C, CDCl3, TMS): d ˆ 158.2, 147.3, 131.0, 129.6,
129.3, 118.0, 114.0, 113.4, 55.2, 45.6, 34.3; MS (70 eV, EI): m/z (%): 227
3
3
3
125.4 (q, J(C,F) ˆ 3.8 Hz), 124.6 (q, J(C,F) ˆ 3.8 Hz), 123.0 (q, J(C,F) ˆ
‡
‡
‡
[M ], 207, 167, 134, 106, 77, 51.
3.8 Hz), 43.0; MS (70 eV, EI): m/z (%): 430 [M À H], 390, 361, 286 [M À
C6H4CF3], 266, 217, 170, 146, 75; C24H15F6N (431.38): calcd C 66.82, H 3.50,
N 3.25; found C 66.70, H 3.66, N 3.26.
2-(3,4-Dimethoxyphenylmethyl)-3-(3,4-dimethoxyphenyl)quinoline (10a):
According to the general procedure, aniline (0.20 mL, 2.2 mmol) was
treated with3,4-dimethoxystyrene (1.63 mL, 11 mmol). After purification
by column chromatography (hexane/ethylacetate gradient 10:1 to 2:1), 10a
was obtained as a yellow oil. Compound 10b was isolated as the by-
product. Yield of 10a: 27% (GC); 210 mg, 23% (isolated); 1H NMR
(400 MHz, 258C, CDCl3, TMS): d ˆ 8.04 (d, 3J(H,H) ˆ 8.1 Hz, 1H; CH),
N-(2-(3-Trifluoromethylphenyl)ethyl)aniline (12b): Yield of 12b: 15%
(GC); 1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 7.53 ± 7.37 (m, 4H;
CH), 7.19 (dd, 3J(H,H) ˆ 8.0, 3J(H,H) ˆ 7.3 Hz, 2H; CH), 6.73 (tt,
3J(H,H) ˆ 7.3, 4J(H,H) ˆ 1.0 Hz, 1H; CH), 6.62 (dt, 3J(H,H) ˆ 8.0,
4J(H,H) ˆ 1.0 Hz, 2H; CH), 3.42 (t, 3J(H,H) ˆ 7.1 Hz, 2H; CH2), 2.97 (t,
3J(H,H) ˆ 7.1 Hz, 2 H ; CH2); 13C NMR (101 MHz, 258C, CDCl3, TMS):
d ˆ 147.6, 140.3, 132.2, 130.9 (q, 2J(C,F) ˆ 32.4 Hz), 129.4, 129.0, 125.5 (q,
3J(C,F) ˆ 3.8 Hz), 123.3 (q, 3J(C,F) ˆ 3.8 Hz), 119.5 (q, 1J(C,F) ˆ 112.5 Hz),
3
3
7.84 (s, 1H; CH), 7.65 (d, J(H,H) ˆ 8.0 Hz, 1H; CH), 7.55 (dd, J(H,H) ˆ
8.1, 3J(H,H) ˆ 7.2 Hz, 1H; CH), 7.39 (dd, 3J(H,H) ˆ 8.0, 3J(H,H) ˆ 7.2 Hz,
1H; CH), 6.74 (d, 3J(H,H) ˆ 8.0 Hz, 1H; CH), 6.70 (s, 1H; CH), 6.54 (d,
3J(H,H) ˆ 8.0 Hz, 1H; CH), 6.42 (d, 3J(H,H) ˆ 8.0 Hz, 1H; CH), 6.30 (d,
3J(H,H) ˆ 8.0 Hz, 1H; CH), 6.25 (s, 1H; CH), 4.25 (s, 2H; CH2), 3.77 (s,
3H; CH3), 3.71 (s, 3H; CH3), 3.70 (s, 3H; CH3), 3.58 (s, 3H; CH3); 13C NMR
(101 MHz, 258C, CDCl3, TMS): d ˆ 166.7, 147.5, 146.4, 146.2, 143.8, 141.4,
139.6, 137.6, 132.8, 129.9, 129.6, 129.3, 127.7, 126.7, 126.2, 121.1, 120.8, 111.3,
110.2, 110.0, 109.8, 55.0, 54.9, 54.7, 54.5, 48.6; MS (70 eV, EI): m/z (%): 414
‡
117.7, 113.0, 44.8, 35.3; MS (70 eV, EI): m/z (%): 265 [M ], 219, 159, 106
‡
[M À CH2 À C6H4CF3], 51.
2-(2-Naphthylmethyl)-3-(2-naphthyl)quinoline (13a): According to the
general procedure, aniline (0.20 mL, 2.2 mmol) was treated with2-vinyl-
naphthalene (1.70 g, 11 mmol). After purification by column chromatog-
raphy (hexane), 13a was obtained as a colorless oil. Compound 13b was
isolated as the by-product. Yield of 13a: 35% (GC); 260 mg, 29%
(isolated); 1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 7.98 ± 7.10 (m,
21H; CH), 4.88 (s, 1H; CH2); 13C NMR (101 MHz, 258C, CDCl3, TMS):
d ˆ 158.7, 143.5, 139.5, 138.7, 134.6, 132.3, 131.6, 131.4, 131.2, 130.9, 129.7,
129.2, 127.3, 127.1, 126.9, 126.7, 126.5, 126.2, 126.1, 125.9, 125.7, 125.0, 124.8,
‡
‡
‡
[M À H], 370, 278 [M À C6H4(OCH3)2], 264 [M À CH2 À C6H3(OCH3)2],
259, 206, 168, 151, 137, 121, 107, 77; C26H25NO4 (415.49): calcd C 75.16, H
6.06, N 3.37; found C 74.97, H 6.36, N 3.26.
N-(2-(3,4-Dimethoxyphenyl)ethyl)aniline (10b): Yield of 10b: 15% (GC);
1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 7.05 (m, 2H; CH), 6.70 (t,
3J(H,H) ˆ 8.0 Hz, 1H; CH), 6.62 (m, 3H; CH), 6.55 (dd, 3J(H,H) ˆ 8.5,
4J(H,H) ˆ 2.0 Hz, 1H; CH), 6.50 (dd, 3J(H,H) ˆ 8.5, 4J(H,H) ˆ 1.0 Hz, 1H;
CH), 3.74 (s, 3H; CH3), 3.73 (s, 3H; CH3), 3.42 (s, 1H; NH), 3.25 (t,
3J(H,H) ˆ 7.0 Hz, 2 H ; CH2), 2.91 (t, 3J(H,H) ˆ 7.1 Hz, 2H; CH2); 13C NMR
(101 MHz, 258C, CDCl3, TMS): d ˆ 148.0, 147.0, 146.6, 130.8, 128.2, 119.6,
117.4, 116.4, 114.0, 112.0, 54.8, 54.7, 44.1, 34.0; MS (70 eV, EI): m/z (%): 257
‡
124.7, 124.1, 123.5, 123.3, 123.2, 40.0; MS (70 eV, EI): m/z (%): 406 [M À
‡
‡
H], 279 [M À C10H7], 265 [M À CH2 À C10H7], 141, 137, 127; C31H21N
(407.51): calcd C 91.36, H 5.19, N 3.44; found C 91.56, H 5.37, N 3.07.
N-(2-(2-Naphthyl)ethyl)aniline (13b): Yield of 13b: 12% (GC); 1H NMR
(400 MHz, 258C, CDCl3, TMS): d ˆ 7.73 ± 7.61 (m, 3H; CH), 7.55 (s, 1H;
CH), 7.36 ± 7.32 (m, 2H; CH), 7.23 (dd, 3J(H,H) ˆ 8.5, 4J(H,H) ˆ 2.0 Hz,
1H; CH), 7.11 ± 7.07 (m, 2H; CH), 6.63 (t, 3J(H,H) ˆ 7.0 Hz, 1H; CH), 6.54
(d, 3J(H,H) ˆ 8.0 Hz, 2H; CH), 3.64 (s, 1H; NH), 3.37 (t, 3J(H,H) ˆ 7.0 Hz,
2H; CH2), 2.96 (t, 3J(H,H) ˆ 7.0 Hz, 2H; CH2); 13C NMR (101 MHz, 258C,
CDCl3, TMS): d ˆ 148.3, 139.6, 137.2, 134.0, 129.8, 128.7, 128.1, 127.8, 127.7,
127.6, 126.7, 125.9, 118.1, 113.6, 45.4, 36.0; MS (70 eV, EI): m/z (%): 247
‡
‡
[M ], 152, 106 [M À CH2 À C6H3(OCH3)2], 91, 77, 65, 51.
2-(4-Methylphenylmethyl)-3-(4-methylphenyl)quinoline (11a): According
to the general procedure, aniline (0.20 mL, 2.2 mmol) was treated with
4-methylstyrene (1.45 mL, 11 mmol). After purification by column chro-
matography (hexane/ethylacetate 10:1), 11a was obtained as an orange oil.
Compound 11b was isolated as the by-product. Yield of 11a: 45% (GC);
313 mg, 44% (isolated); 1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 8.04
(d, 3J(H,H) ˆ 8.5 Hz, 1H; CH), 7.81 (s, 1H; CH), 7.65 (d, 3J(H,H) ˆ 8.0 Hz,
1H; CH), 7.57 (ddd, 3J(H,H) ˆ 8.5, 3J(H,H) ˆ 8.0, 4J(H,H) ˆ 1.0 Hz, 1H;
CH), 7.37 (dd, 3J(H,H) ˆ 8.0, 3J(H,H) ˆ 8.0 Hz, 1H; CH), 7.08 (d,
3J(H,H) ˆ 8.0 Hz, 2H; CH), 7.01 (d, 3J(H,H) ˆ 8.0 Hz, 2H; CH), 6.84 (d,
3J(H,H) ˆ 8.0 Hz, 2H; CH), 6.78 (d, 3J(H,H) ˆ 8.0 Hz, 2H; CH), 4.20 (s,
2H; CH2), 2.31 (s, 3H; CH3), 2.13 (s, 3H; CH3); 13C NMR (101 MHz, 258C,
CDCl3, TMS): d ˆ 159.4, 147.1, 137.2, 136.8, 136.6, 136.4, 136.0, 135.2, 129.3,
129.1, 128.8, 128.7, 128.6, 128.5, 127.4, 126.9, 126.2, 42.2, 21.2, 20.9; MS
‡
[M ], 154, 141, 106, 77, 65.
2-(4-Methylphenylmethyl)-3-(4-methylphenyl)-7-fluoroquinoline (14a):
According to the general procedure, 3-fluoroaniline (0.21 mL, 2.2 mmol)
was treated with4-methylstyrene (1.45 mL, 11 mmol). After purification by
column chromatography (hexane/ethylacetate 20:1), 14a was obtained as a
yellow oil. Compound 14b was isolated as the by-product. Yield of 14a:
15% (GC); 97 mg, 13% (isolated); 1H NMR (400 MHz, 258C, CDCl3,
TMS): d ˆ 7.91 (s, 1H; CH), 7.77 (dd, 3J(H,F) ˆ 10.3, 4J(H,H) ˆ 2.7 Hz, 1H;
CH), 7.74 (dd, 4J(H,F) ˆ 5.9, 3J(H,H) ˆ 8.9 Hz, 1H; CH), 7.29 (td,
3J(H,F) ˆ 3J(H,H) ˆ 8.9, 4J(H,H) ˆ 2.7 Hz, 1H; CH), 7.21 (d, 3J(H,H) ˆ
8.0 Hz, 2H; CH), 7.12 (d, 3J(H,H) ˆ 8.0 Hz, 2H; CH), 6.96 (d, 3J(H,H) ˆ
8.0 Hz, 2H; CH), 6.90 (d, 3J(H,H) ˆ 8.0 Hz, 2H; CH), 4.27 (s, 2H; CH2),
2.43 (s, 3H; CH3), 2.26 (s, 3H; CH3); 13C NMR (101 MHz, 258C, CDCl3,
TMS): d ˆ 162.9 (d, 1J(C,F) ˆ 248.9 Hz), 160.6, 148.0 (d, 3J(C,F) ˆ 12.4 Hz),
137.4, 136.6, 136.4, 136.1, 135.4, 135.3 (d, 4J(C,F) ˆ 2.9 Hz), 129.3, 129.3 (d,
3J(C,F) ˆ 9.5 Hz), 128.9, 128.8, 128.7, 123.8, 116.6 (d, 2J(C,F) ˆ 25.8 Hz),
‡
(70 eV, EI): m/z (%): 322 [M À H], 307, 278, 264, 230, 217, 189, 160, 145,
105, 77, 65; C24H21N (323.44): calcd C 89.12, H 6.54, N 4.33; found C 89.49,
H 6.57, N 3.95.
N-(2-(4-Methylphenyl)ethyl)aniline (11b): Yield of 11b: 6% (GC);
1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 7.29 ± 7.08 (m, 6H; CH),
6.77 (t, 3J(H,H) ˆ 7.0 Hz, 1H; CH), 6.68 (d, 3J(H,H) ˆ 8.0 Hz, 2H; CH),
3.72 (s, 1H; NH), 3.43 (t, 3J(H,H) ˆ 7.0 Hz, 2H; CH2), 2.94 (t, 3J(H,H) ˆ
7.0 Hz, 2H; CH2), 2.39 (s, 3H; CH3); 13C NMR (101 MHz, 258C, CDCl3,
TMS): d ˆ 148.5, 138.5, 136.6, 130.0, 129.3, 128.1, 117.9, 113.4, 45.6, 35.5,
2
112.5 (d, J(C,F) ˆ 20.0 Hz), 42.1, 21.2, 21.0; MS (70 eV, EI): m/z (%): 340
‡
[M À H], 325, 309, 248, 235, 170, 155, 105, 77; C24H20FN (341.43): calcd C
84.43, H 5.90, N 4.10; found C 84.20, H 6.01, N 3.95.
‡
‡
21.5; MS (70 eV, EI): m/z (%): 211 [M ], 106 [M À CH2 À C6H4CH3], 77,
N-(2-(4-Methylphenyl)ethyl)-(3-fluoro)aniline (14b): Yield of 14b: 20%
(GC); 1H NMR (400 MHz, 258C, CDCl3, TMS): d ˆ 7.17 ± 7.04 (m, 5H;
65.
3
CH), 6.41 ± 6.27 (m, 3H; CH), 3.80 (s, 1H; NH), 3.35 (t, J(H,H) ˆ 6.9 Hz,
2-(3-Trifluoromethylphenylmethyl)-3-(3-trifluoromethylphenyl)quinoline
(12a): According to the general procedure, aniline (0.20 mL, 2.2 mmol) was
treated with3-trifluoromethylstyrene (1.63 mL, 11 mmol). After purifica-
tion by column chromatography (hexane/ethylacetate 12:1), 12a was
obtained as an orange oil. Compound 12b was isolated as the by-product.
Yield of 12a: 17% (GC); 152 mg, 16% (isolated); 1H NMR (400 MHz,
2H; CH2), 2.87 (t, 3J(H,H) ˆ 6.9 Hz, 2H; CH2), 2.34 (s, 3H; CH3); 13C NMR
(101 MHz, 258C, CDCl3, TMS): d ˆ 164.1 (d, 1J(C,F) ˆ 243.2 Hz), 149.8 (d,
3J(C,F) ˆ 10.5 Hz), 136.1, 135.8, 130.2 (d, 3J(C,F) ˆ 10.5 Hz), 129.3, 128.6,
4
2
108.8 (d, J(C,F) ˆ 1.9 Hz), 103.7 (d, 2J(C,F) ˆ 21.9 Hz), 99.5 (d, J(C,F) ˆ
‡
‡
25.8 Hz), 44.9, 34.8, 21.0; MS (70 eV, EI): m/z (%): 229 [M ], 124 [M À
CH2 À C6H4CH3], 95.
3
258C, CDCl3, TMS): d ˆ 8.17 (d, J(H,H) ˆ 8.5 Hz, 1H; CH), 7.96 (s, 1H;
CH), 7.81 (d, 3J(H,H) ˆ 8.1 Hz, 1H; CH), 7.76 (dd, 3J(H,H) ˆ 8.5,
3J(H,H) ˆ 7.9 Hz, 1H; CH), 7.63 (d, 3J(H,H) ˆ 7.7 Hz, 1H; CH), 7.57 (dd,
Time-dependent formation of 1a and 1b: The model reaction of styrene
withaniline was performed in eleven independent Ace pressure tubes.
2520
ꢀ WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000
0947-6539/00/0614-2520 $ 17.50+.50/0
Chem. Eur. J. 2000, 6, No. 14

Amination of Aromatic Olefins
2513±2522
[Rh(cod)2]BF4 (45 mg, 0.11 mmol) and PPh3 (116 mg, 0.44 mmol) were
added to eachtube. Toluene (27.50 mL), styrene (13.86 mL, 121 mmol),
aniline (2.20 mL, 24.2 mmol), and hexadecane (0.55 mL) were mixed in a
separate Schlenk vessel. The solution was distributed to the pressure tubes
under an inert atmosphere, and the catalyst concentration was 5 mol%
[Rh(cod)2]BF4/4PPh3. All reaction mixtures were stirred at 1408C. After
30 min and 1, 2, 4, 6, 9, 14, 24, 30, 36, and 48 hours, the corresponding
reaction was stopped by cooling the pressure tube to room temperature.
Each mixture was then analyzed by gas chromatography.
Marks, J. Am. Chem. Soc. 1996, 118, 707; d) Y. Li, T. J. Marks,
Organometallics 1996, 15, 3770; e) C. M. Haar, C. L. Stern, T. J. Marks,
Organometallics 1996, 15, 1765; f) E. L. Eliel, S. H. Wilen, L. N.
Mander, Stereochemistry of Organic Compounds, 11.3c, Wiley, New
York, 1994, 682; g) M. A. Giardell, V. P. Conticello, L. Brard, M. R.
Â
Gagne, T. J. Marks, J. Am. Chem. Soc. 1994, 116, 10241; h) M. A.
Giardello, V. P. Conticello, L. Brard, M. Sabat, A. L. Rheingold, C. L.
Stern, T. J. Marks, J. Am. Chem. Soc. 1994, 116, 10212; i) Y. Li, P. F.
Â
Fu, T. J. Marks, Organometallics 1994, 13, 439; j) M. R. Gagne, C. L.
Â
Stern, T. J. Marks, J. Am. Chem. Soc. 1992, 114, 275; k) M. R. Gagne,
When a reaction mixture, that had been heated for 1 hour, was cooled to
room temperature [Rh(cod)(PPh3)2]BF4 precipitated. The compound was
Â
S. P. Nolan, T. J. Marks, Organometallics 1990, 9, 1716; l) M. R. Gagne,
1
characterized with H, 13C, and 31P NMR spectroscopy.
T. J. Marks, J. Am. Chem. Soc. 1989, 111, 4108.
[6] Y. Li, T. J. Marks, J. Am. Chem. Soc. 1998, 120, 1757.
Reaction of phenylacetaldehyde with aniline: Aniline (1.00 mL, 11 mmol)
and phenylacetaldehyde (1.30 mL, 11 mmol) were dissolved in methanol
(10 mL). The reaction mixture was stirred for 20 h in air. The gas
chromatographic analysis after the reaction showed the selective formation
of 2-benzyl-3-phenylquinoline (1a). Yield of 1a: 29% (GC).
[7] a) M. Beller, M. Eichberger, H. Trauthwein, Angew. Chem. 1997, 109,
2306; Angew. Chem. Int. Ed. Engl. 1997, 36, 2225; b) M. Beller, H.
Trauthwein, M. Eichberger, C. Breindl, J. Herwig, T. E. Müller, O. R.
Thiel, Chem. Eur. J. 1999, 5, 1304.
[8] For domino reactions in organic synthesis see: a) L. F. Tietze, Chem.
Rev. 1996, 96, 115; b) L. F. Tietze, U. Beifuû, Angew. Chem. 1993, 105,
137; Angew. Chem. Int. Ed. Engl. 1993, 32, 131.
2,4-Diphenylquinoline (15): Withthe aid of a pressure tube (35 mL),
[Rh(cod)2]BF4 (45 mg, 0.11 mmol), PPh3 (58 mg, 0.22 mmol), and N-
benzylidenaniline (798 mg, 4.4 mmol) were suspended in toluene (10 mL)
under an argon atmosphere. A dark yellow solution and a white precipitate
were formed. Styrene (2.00 mL, 17.6 mmol) and hexadecane (100 mL) were
added. The reaction vessel was closed cautiously and placed in an oil bath
(1208C). The reaction mixture was stirred for 28 h, and a bright yellow
solution was produced. The solvent was removed in vacuo. The crude
product was purified by column chromatography with hexane/ethylacetate
(50:1) as the eluent. Compound 15 was isolated as a yellow oil. Yield of 15:
21% (GC); 247 mg, 20% (isolated); 1H NMR (400 MHz, 258C, CDCl3,
[9] G. Habermehl, P. E. Hammann, Naturstoffchemie, Springer, Berlin,
1992, p. 192.
[10] M. Balasubramanian, J. G. Keay in Comprehensive Heterocyclic
Chemistry II, Vol. 5 (Ed.: A. McKillop), Elsevier, 1996, p. 245.
[11] a) H. Auterhoff, J. Knabe, H.-D. Höltje, Lehrbuch der Pharmazeuti-
schen Chemie, 12. Aufl., Wissenschaftliche Verlagsgesellschaft, Stutt-
gart, 1991; b) E. Mutschler, Arzneimittelwirkungen, 6. Aufl., Wissen-
schaftliche Verlagsgesellschaft, Stuttgart, 1991.
[12] a) G. Jones, The Chemistry of Heterocyclic Compounds, Vol. 32,
Quinolines, Wiley, London, 1977; b) Z. H. Skraup, Monatsh. Chem.
1880, 1, 316; c) O. Doebner, W. von Miller, Ber. 1881, 14, 2812; d) M.
Conrad, L. Limbach, Ber. 1887, 20, 944; e) A. Combes, Compt. Rend.
1888, 106, 142; e) P. Friedländer, Ber. 1882, 15, 2572; f) W. Pfitzinger,
J. Prakt. Chem. 1886, 33, 100.
[13] a) L. S. Povarov, B. M. Mikhailov, Izv. Akad. Nauk SSSR Ser. Khim.
1963, 955; b) L. S. Povarov, V. I. Grigos, B. M. Mikhailov, Izv. Akad.
Nauk SSSR Ser. Khim. 1963, 2039; c) L. S. Povarov, V. I. Grigos, R. A.
Karakhanov, B. M. Mikhailov, Izv. Akad. Nauk SSSR Ser. Khim. 1964,
179; d) L. S. Povarov, V. I. Grigos, R. A. Karakhanov, B. M. Mikhai-
lov, Izv. Akad. Nauk SSSR Ser. Khim. 1965, 365; e) V. I. Grigos, L. S.
Povarov, B. M. Mikhailov, Izv. Akad. Nauk SSSR Ser. Khim. 1965,
2163.
[14] For further examples of hetero-Diels ± Alder reactions see: a) C. K.
Bradsher in Advances in Heterocyclic Chemistry, Vol. 16 (Eds.: A. K.
Katritzky, A. J. Bouilon), 1974, p. 289; b) N. S. Kozlov, L. Yu, Zh.
Obshch. Khim. 1963, 33, 1079; c) T. Joh, N. Hagihara, Tetrahedron
Lett. 1967, 4199; d) T. Joh, N. Hagihara, Nippon Kagaku Kaishi 1970,
91, 378; e) T. Joh, N. Hagihara, Nippon Kagaku Kaishi 1970, 91, 383;
f) Y. Nomura, M. Kimura, Y. Takeuchi, S. Tomoda, Chem. Lett. 1978,
267; g) S. Miyajima, K. Ito, I. Kashiwagura, C. Kitamura, Nippon
Kagaku Kaishi 1979, 11, 1514; h) T. Kametami, H. Takeda, Y. Suzuki,
T. Honda, Heterocycles 1984, 22, 275; i) T. Kametami, H. Takeda, Y.
Suzuki, T. Honda, Synth. Commun. 1985, 15, 499.
3
TMS): d ˆ 7.98 (d, J(H,H) ˆ 8.4 Hz, 1H; CH), 7.92 (m, 2H; CH), 7.63 (d,
3J(H,H) ˆ 8.4 Hz, 1H; CH), 7.54 (s, 1H; CH), 7.45 (m, 1H; CH), 7.27 ± 6.87
(m, 9H; CH); 13C NMR (101 MHz, 258C, CDCl3, TMS): d ˆ 156.8,
149.2, 148.8, 139.6, 138.4, 130.7, 130.1, 129.6, 129.5, 129.3, 128.6, 128.4,
‡
127.6, 126.3, 125.0, 119.3; MS (70 eV, EI): m/z (%): 280 [M À H], 204
‡
[M À C6H5], 139.
Acknowledgements
We thank Dr. A. Tillack (IfOK, Rostock) for general discussions and Dr.
M. Hateley (IfOK, Rostock) for helpful comments on the manuscript.
Degussa AG, Hoechst AG, and Heraeus AG are thanked for the loan of
precious metals. H.T. acknowledges funding from the Fonds der Chem-
ischen Industrie. We also thank the Deutsche Forschungsgemeinschaft
(BE1931/3-1) for financial support.
[1] H. Trauthwein, A. Tillack, M. Beller, Chem. Commun. 1999,
2029.
[2] Reviews: a) M. Beller, T. E. Müller, Chem. Rev. 1998, 98, 675; b) M.
Beller, T. E. Müller in Transition Metals for Organic Synthesis (Eds.:
M. Beller, C. Bolm), Wiley-VCH, Weinheim, 1998; c) R. Taube in
Applied Homogeneous Catalysis with Organometallic Compounds
(Eds.: B. Cornils, W. A. Herrmann), VCH, Weinheim, 1996, p. 507;
d) D. M. Roundhill, Chem. Rev. 1992, 92, 1; e) J.-J. Brunet, D.
Neibecker, F. Niedercorn, J. Mol. Catal. 1989, 49, 235; f) M. B. Gasc,
A. Lattes, J. J. Perie, Tetrahedron 1983, 39, 703; g) J.-E. Bäckvall, Acc.
Chem. Res. 1983, 16, 335; h) V. Jäger, H. G. Viehe, Houben-Weyl,
Methoden der Organischen Chemie, Vol. 5/2a, Thieme, Stuttgart, 1977,
p. 713.
[15] For rhodium complexes with pyridine and quinoline ligands see: a) T.
Masahiko, Y. Hiroshi, N. Hagihara, Nipon Kagaku Zasshi 1968, 89,
1121; b) B. Denise, G. Pannetier, J. Organomet. Chem. 1973, 63, 423;
Â
c) R. Uson, L. A. Oro, C. Claver, M. A. A. Garralda, J. Organomet.
Chem. 1976, 105, 365; d) R. Uson, L. A. Oro, J. A. Cuchi, M. A. A.
Garralda, J. Organomet. Chem. 1976, 116, C35; e) R. Uson, L. A. Oro,
R. Sariego, M. A. Esteruelas, J. Organomet. Chem. 1981, 214, 399;
f) R. H. Fish, J. L. Tan, A. D. Thormodsen, J. Org. Chem. 1984, 49,
4500; g) R. H. Fish, H.-S. Kim, J. E. Babin, R. D. Adams, Organo-
metallics 1988, 7, 2250.
Â
Â
[3] a) L. S. Hegedus, J. M. McKearin, J. Am. Chem. Soc. 1982, 104, 2444;
b) L. S. Hegedus, G. F. Allen, J. J. Bozell, E. L. Waterman, J. Am.
Chem. Soc. 1978, 100, 5800; c) B. Škermark, J. E. Bäckvall, L. S.
[16] M. Beller, O. R. Thiel, H. Trauthwein, Synlett. 1999, 2, 243.
[17] G. Lewin, C. Schaeffer, Heterocycles 1998, 48, 171.
Â
Hegedus, K. Zetterberg, K. Siirala-Hansen, K. Sjöberg, J. Organomet.
[18] a) J.-J. Brunet, D. Neibecker, K. Philippot, J. Chem. Soc. Chem.
Commun. 1992, 1215; b) J.-J. Brunet, D. Neibecker, K. Philippot,
Tetrahedron Lett. 1993, 34, 3877; c) J.-J. Brunet, G. Commenges, D.
Neibecker, K. Philippot, J. Organomet. Chem. 1994, 469, 221.
[19] a) S. E. Diamond, G. F. Allen, E. L. Waterman, J. Am. Chem. Soc.
1979, 101, 490; b) S. E. Diamond, F. Mares, (Allied Chemical Corp.),
US4215218, 1980; [Chem. Abstr. 1980, 93, 185931].
Chem. 1974, 72, 127; d) L. S. Hegedus, Angew. Chem. 1988, 100, 1147;
Angew. Chem. Int. Ed. Engl. 1988, 27, 1113.
[4] R. C. Larock, T. R. Hightower, L. A. Hasvold, K. P. Peterson, J. Org.
Chem. 1996, 61, 3584.
[5] For hydroamination catalyzed by lanthanide complexes see: a) M. R.
Bürgstein, H. Berbeich, P. W. Roesky, Organometallics 1998, 17, 1452;
b) Y. Li, T. J. Marks, J. Am. Chem. Soc. 1996, 118, 9295; c) Y. Li, T. J.
Chem. Eur. J. 2000, 6, No. 14
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FULL PAPER
[20] a) Y. Makioka, T. Shindo, Y. Taniguchi, K. Takaki, Y. Fujiwara,
Synthesis 1995, 801; b) S. Kobayashi, H. Ishitani, S. Nagayama,
Synthesis 1995, 1195; c) S. Kobayashi, H. Ishitani, S. Nagayama,
Chem. Lett. 1995, 423.
[23] R. R. Schrock, J. A. Osborn, J. Am. Chem. Soc. 1971, 93, 3089.
[24] D. Hunter, D. G. Neilson, T. J. R. Weakly, J. Chem. Soc. Perkin Trans 1
1985, 2709.
[21] H. Ishitani, S. Kobayashi, Tetrahedron Lett. 1996, 37, 7357.
[22] G. Giordano, R. H. Crabtree, Inorg. Synth. 1979, 19, 218.
Received: September 21, 1999 [F2046]
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