Ruthenium-catalyzed formal alkyl group transfer: Synthesis of quinolines from nitroarenes and alkylammonium halides

Article abstract of DOI:10.1002/jhet.5570410320

Nitroarenes are reductively cyclized with an array of tetraalkylammonium halides and trialkylammonium chlorides in the presence of a catalytic amount of a ruthenium catalyst along with tin(II) chloride dihydrate at 180° to afford the corresponding quinolines in moderate to good yields. The addition of tin(lI) chloride dihydrate is necessary for the effective formation of quinolines and toluene is the solvent of choice. A reaction pathway involving initial reduction of nitroarenes to anilines and conversion of alkylammonium halides to alkylamines, alkyl group transfer from alkylamines to anilines to form an imine, dimerization of imine, and heteroannulation is proposed for this catalytic process.

Full text of DOI:10.1002/jhet.5570410320

May-Jun 2004
Ruthenium-Catalyzed Formal Alkyl Group Transfer: Synthesis of
Quinolines from Nitroarenes and Alkylammonium Halides
Chan Sik Cho*
423
Research Institute of Industrial Technology, Kyungpook National University,
Daegu 702-701, Korea
Na Young Lee, Tae-Jeong Kim and Sang Chul Shim*
Department of Applied Chemistry, College of Engineering, Kyungpook National University,
Daegu 702-701, Korea
Received November 25, 2003
Nitroarenes are reductively cyclized with an array of tetraalkylammonium halides and trialkylammonium
chlorides in the presence of a catalytic amount of a ruthenium catalyst along with tin(II) chloride dihydrate
at 180° to afford the corresponding quinolines in moderate to good yields. The addition of tin(II) chloride
dihydrate is necessary for the effective formation of quinolines and toluene is the solvent of choice. A reac-
tion pathway involving initial reduction of nitroarenes to anilines and conversion of alkylammonium halides
to alkylamines, alkyl group transfer from alkylamines to anilines to form an imine, dimerization of imine,
and heteroannulation is proposed for this catalytic process.
J. Heterocyclic Chem., 41, 423 (2004).
Introduction.
of anilines with alkylammonium halides leading to quino-
lines via an intrinsic amine exchange reaction.
It is known that many quinoline containing compounds
exhibit a wide spectrum of pharmacological and biological
activities [1]. Thus, besides conventional named routes
such as Skraup, Döbner-von Miller, Conrad-Limpach,
Friedländer and Pfitzinger syntheses [2], homogeneous
transition metal-catalyzed synthetic methods have been
attempted for the construction of quinoline framework
because of the facility and efficiency of reaction and wide
availability of substrate [3]. In connection with this report,
during the course of our ongoing studies on homogeneous
ruthenium catalysis [4-10], we have also reported on con-
struction of quinolines via ruthenium-catalyzed alkyl
group transfer from alkylamines (Scheme 1, route a)
[
3a,5a-5c] and alkanolamines (Scheme 1, route b) [5d,5e]
to N-atom of anilines (amine exchange reaction [11]) and
oxidative cyclization of 2-aminobenzyl alcohol with
ketones [12] and secondary alcohols [13] (modified
Friedländer quinoline synthesis [14]). The amine exchange
reaction has been used for the synthesis of unsymmetrical
amines and N-heterocycles and the study of the metabo-
lism of amines [11]. However, except for our findings, a
clear-cut example for the synthesis of N-heterocycles
using amine exchange reaction as yet seems to be limited
to palladium-catalyzed synthesis of hydropyrimidines,
imidazolidines and imidazoles [15]. Prompted by these cir-
cumstances, we also reported the direct use of nitroarenes
instead of anilines for such heterocycles since nitroarenes
are precursors of anilines from the viewpoint of industrial
organic chemistry [16,17]. Herein, as another example for
the synthesis of N-heterocycles using amine exchange
reaction and nitroarenes, we report a ruthenium-catalyzed
in situ reduction of nitroarenes to anilines and cyclization
Results and Discussion.
The results of several attempted reductive cyclizations
between nitrobenzene (1 a) and tetrabutylammonium bro-
mide (2 a) under various conditions to achieve effective for-
mation of 3-ethyl-2-propylquinoline (3a) are listed in Table
1 (Scheme 2). Generally, 1a was subjected to react with 2a
in the presence of a catalytic amount of a ruthenium cata-
lyst (2-3 mol% based on 2a) at 180° for 20 hours to afford
3a. The molar ratio of [1a]/[2a] = 2 was the choice of pref-
erence for the effective formation of 3 a. The addition of an
appropriate amount of SnCl •2H O was necessary for the
2
2
effective formation of 3a (runs 1-4). The absence of
SnCl •2H O resulted in incomplete conversion of 1a to
2
2
aniline (run 4). This result indicates that SnCl •2H O plays
a role for the reduction of 1a to aniline. It is known that
2
2

424
C. S. Cho, N. Y. Lee, T.-J. Kim and S. C. Shim
Vol. 41
nitroarenes can be easily converted into anilines in the pres-
ence of SnCl •2H O under nonacidic and nonaqueous
2
2
media [18]. However, as has been observed in our recent
report on the synthesis of indoles and quinolines from ani-
lines and alkylamines, another feature of SnCl •2H O
2
2
seems to play a decisive role in either alkyl group transfer
or heteroannulation step [4,5]. As shown in Table 1, among
the activity of various ruthenium precursors examined
R u C l ( P P h ) , RuCl •nH O combined with PPh ,
2
3 3
3
2
3
RuH (PPh ) , and Cp*RuCl (CO) revealed to be effective
2
3 4
2
toward the formation of 3a (runs 5-10). Finally, among sol-
vents examined toluene turned out to be the most effective
for the formation of 3a (runs 11-14). Interestingly, much
more N-butylaniline (54%) was formed under the employ-
The present reductive heteroannulation could also be
applied to many nitroarenes 1 as well as tetraalkylammo-
nium bromides 2 under two sets of reaction conditions, and
several representative results are summarized in Table 2. In
all cases, as is the solvent for the reaction of 1a with 2a,
toluene was suitable for the formation of quinolines. Table
ment of dioxane/H O (9 mL/1 mL) compared to that of
2
other solvents (3-29%) (run 12).
2
shows that the quinoline yield was considerably affected
by the position of the substituent on the nitroarene, whereas
the electronic nature of that had no relevance to the product
yield. With p a r a- and meta-substituted nitroarenes (1b and
1
c), the quinoline yield was higher than that when ortho-
Table 1
Optimization of Conditions for Reductive Cyclization of 1a with 2a Leading to 3a [a]
Run
Ruthenium catalysts (mmol)
RuCl (PPh ) (0.02)
SnCl •2H O (mmol)
Solvents
Conv. (%) of 1a
GLC yield (%) [b]
2
2
1
2
3
4
5
6
7
8
9
1
0.2
2
-
dioxane
dioxane
dioxane
dioxane
dioxane
dioxane
dioxane
dioxane
dioxane
dioxane
dioxane
100
65
100
51
50
23
35
24
48
38
48
13
48
37
67
24
50
88
2
3 3
RuCl (PPh ) (0.02)
2
3 3
RuCl (PPh ) (0.02)
2
3 3
RuCl (PPh ) (0.02)
2
3 3
RuCl •nH O (0.02)/3PPh
1
1
1
1
1
1
1
1
1
1
100
100
100
100
66
100
100
100
100
100
3
2
3
RuCl •nH O (0.02)/1.5dppm [c]
3
2
RuH (PPh ) (0.02)
2
3 4
RuCl (=CHPh)(PCy ) (0.02)
2
3 2
Cp*RuCl (CO) [d] (0.02)
2
10
Ru (CO) (0.02)
3
12
1
1
RuCl (PPh ) (0.03)
2 3 3
1
1
1
2
3
4
RuCl (PPh ) (0.03)
dioxane/H O [e]
THF
toluene
2
3 3
2
RuCl (PPh ) (0.03)
2
3 3
RuCl (PPh ) (0.03)
2
3 3
o
[
a] Reaction conditions: 1a (2 mmol), 2a (1 mmol), solvent (10 mL), 180 , for 20 hours, under Ar; [b] Based on 2a. [c] Bis(diphenylphosphino)methane.
[
d] Cp* = pentamethylcyclopentadienyl. [e] Dioxane/H O = 9 mL/1 mL.
2
First, given these results, the reactions of 1a with
substituted nitroarene 1d was used. In the case of 3-nitro-
toluene (1c ), the corresponding quinolines 3d were
obtained as a regioisomeric mixture, favoring the 7-methyl
isomer which was formed via the less sterically hindered
position on 1c. Furthermore, although product yield in
toluene was superior to that in dioxane, regioisomers were
obtained with the same molar distribution. From the reac-
tion of various nitroarenes bearing electron donating (1 e
tetrapropylammonium halides (2 b-2 d) were screened in
order to compare the reactivity of halides analogues under
two sets of reaction conditions shown in entries 11 and 14
of Table 1 (Scheme 3). Much more 2-ethyl-3-methyl-
quinoline (3b) was formed with the employment of
tetrapropylammonium bromides (2c) and iodide (2d) com-
pared to that of chloride analogue 2b.

May-Jun 2004
Ruthenium-Catalyzed Formal Alkyl Group Transfer
425
and 1 f) and withdrawing (1 g-1 j) substituents with 2 a, the
corresponding quinolines (3f-3 k) were also formed in mod-
erate to good yields. Nitroarenes also reacted with an array
of tetraalkylammonium bromides (2 e-2h) and the corre-
sponding quinolines (3 l-3 r) were obtained in similar yields
irrespective of the alkyl chain length on 2 e-2 h. As has been
observed in our recent reports on ruthenium-catalyzed syn-
thesis of indoles and quinolines [4,5], in the reactions of
two-methyl substituted nitroarene 1f with tetraalkylammo-
nium bromides (2 a, 2 e, and 2 f), much more product yield
was observed when compared with mono-substituted
nitroarenes.
Next, we examined a similar reductive heteroannulation
of nitroarenes 1 with trialkylammonium chlorides 4 under
RuCl (PPh ) /SnCl •2H O/toluene conditions. Several
2
3 3
2
2
representative results were summarized in Table 3. The
reactions of 1a with several trialkylammonium chlorides
(4a-4e) proceed to afford the corresponding quinolines (3a
and 3s-3v) with concomitant formation of aniline and N-
alkylanilines. Here, in contrast to the reaction of 1 with 2,
the product yield decreased with the increase of the alkyl
chain length on 4a-4d. Lower yield was observed with tri-
amylammonium chloride (4e) having branched alkyl chain
when compared to that with straight trialkylammonium

426
C. S. Cho, N. Y. Lee, T.-J. Kim and S. C. Shim
Vol. 41
chlorides (4 a and 4 b ) having similar chain length.
Nitroarenes such as 1b and 1f were also reacted with tri-
alkylammonium chlorides (4b and 4d) to give the corre-
sponding quinolines (3o, 3w, and 3x).
Markovnikov hydroamination to form an enamine, isomer-
ization of enamine to tautomeric imine, and imine dimeriza-
tion [22]. A similar catalytic cycle has also been made by
others [23] and in our recent report [5c].
Although the present reaction pathway including the
exact role of SnCl •2H O is not yet fully understood [19],
2
2
the outline of the reaction scheme, consistent with the prod-
uct and by-product formed, is shown in Scheme 4. The start-
ing nitrobenzene 1a and alkylammonium halides (2 and 4)
seem initially to be converted into aniline 5 and alkylamine
6
, respectively. It appears that the latter transformation
occurs for easy coordination of tertiary amine to catalyst
ruthenium [20]. An alkyl group transfer from 6 to N-atom of
5
gives an imine 7 with concomitant formation of N-alky-
laniline through several known mechanistic sequences,
which is described in our recent report [5b,5c]. This alkyl
group transfer is known as an amine exchange reaction
(amine scrambling reaction) [11]. Although we have no evi-
dence for the generation of 7, the formation of N-alkylani-
line in all cases shown in Table 2 supports the presence of 7
in the reaction course as an intermediate. It is well known
that the intermolecular alkyl group transfer between alky-
lamines proceeds through an imine or iminium ion complex
under transition metals [11]. Subsequent step seems to pro-
ceed via the known Schiff-base dimerization [21] to form
quinoline 3. It was reported by Beller et al. that anilines
react with styrenes to give quinolines via initial anti-
Conclusion.
We have demonstrated that nitroarenes can be reduc-
tively cyclized with tetraalkylammonium halides as well
as trialkylammonium chlorides in the presence of a ruthe-

May-Jun 2004
Ruthenium-Catalyzed Formal Alkyl Group Transfer
427
nium catalyst and SnCl •2H O to afford quinolines in
2-Butyl-3-propylquinoline (3l) [26].
2
2
moderate to good yields. The present reaction is another
example for the synthesis of N-heterocycles using amine
exchange reaction by the direct use of nitroarenes.
1
This compound was obtained as a pale yellow oil; H NMR
(400 MHz, CDCl ): δ 0.98 (t, J = 7.0 Hz, 3H), 1.04 (t, J = 7.0 Hz,
3H), 1.45-1.54 (m, 2H), 1.67-1.82 (m, 4H), 2.75 (t, J = 7.5 Hz,
H), 2.98 (t, J = 8.0 Hz, 2H), 7.42 (t, J = 7.6 Hz, 1H), 7.60 (t, J =
.8 Hz, 1H), 7.70 (d, J = 8.7 Hz, 1H), 7.82 (s, 1H), 8.01 (d, J = 8.0
Hz, 1H); C NMR (100 MHz, CDCl ): δ 14.07, 14.09, 23.07,
3
2
7
1
3
3
EXPERIMENTAL
2
1
3.60, 31.91, 34.42, 35.67, 125.51, 126.88, 127.20, 128.32,
28.46, 133.86, 134.85, 146.51, 162.31; ms: m/z (%) 228 (M ,
+
1H- and 13C-NMR (400 and 100 MHz) spectra were recorded
on a Bruker Avance Digital 400 spectrometer using TMS as an
internal standard. Infrared spectra were obtained on a Mattson
Galaxy 7020A spectrophotometer. The GLC analyses were car-
ried out with Shimadzu GC-17A (FID) equipped with CBP10-
S25-050 column (Shimadzu, a silica fused capillary column, 0.33
25), 157 (100).
-Butyl-6-methyl-3-propylquinoline (3m).
This compound was obtained as a pale yellow oil; H NMR
2
1
(400 MHz, CDCl ): δ 0.96-1.03 (m, 6H), 1.44-1.53 (m, 2H),
3
1.64-1.71 (m, 2H), 1.73-1.81 (m, 2H), 2.45 (s, 3H), 2.71 (t, J =
7.5 Hz, 2H), 2.94 (t, J = 8.0 Hz, 2H), 7.38-7.42 (m, 2H), 7.69 (s,
mm x 25 m, 0.25 µm film thickness) using N as carrier gas.
2
Mass spectra were obtained using EI ionization at 70 eV. The iso-
lation of pure products was carried out via column chromatogra-
phy (silica gel 60, 70-230 mesh, Merck) and thin layer chro-
matography (silica gel 60 GF254, Merck). Commercially avail-
able organic and inorganic compounds were used without further
purification. Cp*RuCl (CO) [24] and RuCl (PPh ) [25] were
1H), 7.91 (d, J = 8.5 Hz, 1H); 13C NMR (100 MHz, CDCl ): δ
3
14.07 (x2), 21.47, 23.08, 23.61, 31.91, 34.44, 35.56, 125.77,
127.23, 128.19, 130.53, 133.74, 134.25, 135.11, 145.14, 161.23;
+
ms: m/z (%) 241 (M , 25), 171 (100).
Anal. Calcd. for C H N: C, 84.59; H, 9.60; N, 5.80. Found:
1
7 23
C, 84.28; H, 9.68; N, 5.63.
-Butyl-5,7-dimethyl-3-propylquinoline (3n).
This compound was obtained as a pale yellow oil; H NMR
400 MHz, CDCl ): δ 0.92 (t, J = 7.5 Hz, 3H), 1.04 (t, J = 7.5 Hz,
2
2
3 3
prepared by the reported methods.
2
General Procedure for Ruthenium-Catalyzed Reactions between
1
1a and 2a (for GLC Analysis).
(
3
A mixture of 1a (246 mg, 2 mmol), 2a (322 mg, 1 mmol),
3H), 1.44-1.53 (m, 2H), 1.66-1.81 (m, 4H), 2.47 (s, 3H), 2.60 (s,
3H), 2.76 (t, J = 8.0, 2H), 2.94 (t, J = 7.8 Hz, 2H), 7.10 (s, 1H),
ruthenium catalyst (0.02-0.03 mmol), SnCl •2H O (0-1 mmol) in
2
2
solvent (10 mL) was charged in 50 mL stainless steel autoclave.
After the system was flushed with argon, the resulting mixture
was stirred at 180° for 20 hours. The reaction mixture was fil-
tered through a short silica gel column (ethyl acetate-chloroform
mixture) to eliminate inorganic salts. To the extract was added
appropriate amount of internal standard and analyzed by GLC.
7.66 (s, 1H), 7.91 (s, 1H); 13C NMR (100 MHz, CDCl ): δ 14.08,
3
14.13, 18.51, 21.72, 23.08, 24.02, 31.98, 34.79, 35.54, 124.46,
125.82, 128.34, 131.37, 132.49, 133.26, 137.96, 147.05, 161.59;
+
ms: m/z (%) 255 (M , 8), 185 (100).
Anal. Calcd. for C H N: C, 84.65; H, 9.87; N, 5.48. Found:
1
8 25
C, 84.43; H, 9.71; N, 5.65.
General Procedure for Ruthenium-Catalyzed Synthesis of 3 from
2-Hexyl-6-methyl-3-pentylquinoline (3q).
1
and 2 (or 4) (for Isolation).
1
This compound was obtained as a pale yellow oil; H NMR
A mixture of 1 (2 mmol), 2 or 4 (1 mmol), RuCl (PPh ) (29
(400 MHz, CDCl ): δ 0.88-0.94 (m, 6H), 1.32-1.48 (m, 10H),
2
3 3
3
mg, 0.03 mmol), and SnCl •2H O (226 mg, 1 mmol) in dioxane
1.64-1.70 (m, 2H), 1.94-1.98 (m, 2H), 2.48 (s, 3H), 2.75 (t, J =
7.5 Hz, 2H), 2.94 (t, J = 7.5 Hz, 2H), 7.42 (d, J = 8.5 Hz, 1H),
7.46 (s, 1H), 7.73 (s, 1H), 7.90 (d, J = 8.5 Hz, 1H); 13C NMR
2
2
or toluene was charged in 50 mL stainless steel autoclave. After
the system was flushed with argon, the reaction mixture was
stirred at 180° for 20 hours. The reaction mixture was filtered
through a short silica gel column (ethyl acetate-chloroform mix-
ture) to eliminate inorganic salts and the filtrate was concentrated
under reduced pressure. The residual mixture was separated by
TLC or column chromatography to give quinolines. All products
prepared by this procedure, except for the following compounds,
were noted in our recent reports [3a,13,16c].
(100 MHz, CDCl ): δ 14.05, 14.11, 21.51, 22.58, 22.65, 29.66,
3
29.80, 30.26, 31.79, 31.82, 32.39, 35.91, 125.76, 127.25, 128.18,
130.53, 134.05, 134.22, 135.14, 145.11, 161.30; ms: m/z (%) 297
+
(M , 6), 171 (100).
Anal. Calcd. for C H N: C, 84.79; H, 10.50; N, 4.71. Found:
2
1 31
C, 84.63; H, 10.44; N, 4.81.
-Heptyl-3-hexylquinoline (3t).
This compound was obtained as a pale yellow oil; H NMR
2
Methyl 3-Ethyl-2-propylquinoline-6-carboxylate (3k).
1
This compound was obtained as a pale yellow oil; ir (neat): ν
(400 MHz, CDCl ): δ 0.87-0.92 (m, 6H), 1.25-1.48 (m, 14H),
3
-1 1
1
717 (C=O) cm ; H NMR (400 MHz, CDCl ): δ 1.08 (t, J = 7.5
1.64-1.71 (m, 2H), 1.75-1.83 (m, 2H), 2.77 (t, J = 7.5 Hz, 2H),
2.97 (t, J = 8.0 Hz, 2H), 7.40-7.44 (m, 1H), 7.57-7.61 (m, 1H),
7.70 (d, J = 7.5 Hz, 1H), 7.82 (s, 1H), 8.01 (d, J = 8.6 Hz, 1H);
3
Hz, 3H), 1.35 (t, J = 7.5 Hz, 3H), 1.81-1.90 (m, 2H), 2.85 (q, J =
7
8
(
1
1
(
.5 Hz, 2H), 2.97 (t, J = 8.0 Hz, 2H), 3.98 (s, 3H), 7.94 (s, 1H),
.03 (d, J = 9.0 Hz, 1H), 8.20 (dd, J = 9.0 and 2.0 Hz, 1H), 8.50
1
3
C NMR (100 MHz, CDCl ): δ 14.11 (x2), 22.63, 22.68, 29.26,
3
1
3
d, J = 1.5 Hz, 1H); C NMR (100 MHz, CDCl ): δ 14.16,
29.31, 29.82, 29.94, 30.53, 31.73, 31.85, 32.41, 35.96, 125.51,
126.86, 127.25, 128.30, 128.45, 134.15, 134.80, 146.50, 162.32.
3
4.31, 22.57, 25.07, 37.86, 52.23, 126.40, 127.00, 127.87,
28.69, 130.19, 134.78, 136.27, 148.27, 164.59, 166.91; ms: m/z
Anal. Calcd. for C H N: C, 84.83; H, 10.68; N, 4.50. Found:
22 33
+
%) 257 (M , 39), 229 (100).
C, 84.70; H, 10.74; N, 4.67.
Anal. Calcd. for C16 H19NO : C, 74.68; H, 7.44; N, 5.44.
2
Found: C, 74.34; H, 7.40; N, 5.62.
3-Decyl-2-undecylquinoline (3u).

428
C. S. Cho, N. Y. Lee, T.-J. Kim and S. C. Shim
Vol. 41
1
such as Pd, Rh, Ru and Fe, see: C. S. Cho, B. H. Oh, J. S. Kim, T.-J.
Kim and S. C. Shim, Chem. Commun., 1885 (2000) and references cited
therein; [b] H. Amii, Y. Kishikawa and K. Uneyama, Org. Lett., 3, 1109
This compound was obtained as a yellowish brown oil; H
NMR (400 MHz, CDCl ): δ 0.86-0.89 (m, 6H), 1.26-1.48 (m,
3
3
2
1
1
2
1
0H), 1.65-1.72 (m, 2H), 1.74-1.82 (m, 2H), 2.78 (t, J = 8.0 Hz,
H), 2.97 (t, J = 8.0 Hz, 2H), 7.42-7.45 (m, 1H), 7.58-7.62 (m,
H), 7.71 (d, J = 8.0 Hz, 1H), 7.84 (s, 1H), 8.01 (d, J = 8.5 Hz,
(
2001) and references cited therein.
[4a] C. S. Cho, H. K. Lim, S. C. Shim, T. J. Kim and H.-J. Choi,
Chem. Commun., 995 (1998); [b] C. S. Cho, J. H. Kim and S. C. Shim,
Tetrahedron Letters, 41, 1811 (2000); [c] C. S. Cho, J. H. Kim, T.-J.
Kim and S. C. Shim, Tetrahedron, 57, 3321 (2001).
H); 13C NMR (100 MHz, CDCl ): δ 14.12, 22.70, 29.37, 29.52,
3
9.63, 29.66, 29.69, 29.81, 29.98, 30.57, 31.94, 32.42, 35.97,
25.52, 126.87, 127.25, 128.31, 128.47, 134.18, 134.83, 162.35.
[5a] C. S. Cho, B. H. Oh and S. C. Shim, Tetrahedron Letters, 40,
Several peaks are eclipsed.
Anal. Calcd. for C H N: C, 85.04; H, 11.66; N, 3.31. Found:
1
499 (1999); [b] C. S. Cho, B. H. Oh, S. C. Shim and D. H. Oh, J.
3
0
49
Heterocyclic Chem., 37, 1315 (2000); [c] C. S. Cho, J. S. Kim, B. H.
Oh, T.-J. Kim, S. C. Shim and N. S. Yoon, Tetrahedro n, 5 6, 7747
(
C, 85.17; H, 11.75; N, 3.22.
-iso-Butyl-3-iso-propylquinoline (3v) [27].
This compound was obtained as a pale yellow oil; H NMR
400 MHz, CDCl ): δ 1.00 (d, J = 6.5 Hz, 6H), 1.33 (d, J = 6.5
2000); [d] C. S. Cho, B. H. Oh and S. C. Shim, J. Heterocyclic Chem.,
6, 1175 (1999); [e] C. S. Cho, D. T. Kim, T.-J. Kim and S. C. Shim,
2
3
1
Bull. Korean Chem. Soc., 24, 1026 (2003).
[6] C. S. Cho, B. T. Kim, M. J. Lee, T.-J. Kim and S. C. Shim,
Angew. Chem. Int. Ed. Engl., 40, 958 (2001).
(
3
Hz, 6H), 2.21-2.32 (m, 1H), 2.92 (d, J = 7.5 Hz, 2H), 3.32 (sept, J
6.5 Hz, 1H), 7.42-7.46 (m, 1H), 7.58-7.62 (m, 1H), 7.73 (d, J =
[7a] C. S. Cho, B. T. Kim, T.-J. Kim and S. C. Shim, J. Org.
=
8
.0 Hz, 1H), 7.94 (s, 1H), 8.02 (d, J = 8.5 Hz, 1H); 13C NMR
Chem., 66, 9020 (2001); [b] C. S. Cho, B. T. Kim, T.-J. Kim and S. C.
Shim, Tetrahedron Letters, 43, 7987 (2002); [c] C. S. Cho, B. T. Kim,
H.-S. Kim, T.-J. Kim and S. C. Shim, Organometallics, 22, 3608
(
100 MHz, CDCl ): δ 22.63, 23.87, 28.81, 29.40, 44.12, 125.50,
3
1
27.03, 127.29, 128.33, 128.52, 131.53, 140.75, 146.17, 160.77.
(
2003).
[8] C. S. Cho, J. H. Park, T.-J. Kim and S. C. Shim, Bull. Korean
Chem. Soc., 23, 23 (2002).
9] B. T. Kim, C. S. Cho, T.-J. Kim and S. C. Shim, J. Chem.
Research (S), 368 (2003).
10] C. S. Cho, J. H. Kim, H.-J. Choi, T.-J. Kim and S. C. Shim,
3
-Decyl-6-methyl-2-undecylquinoline (3w).
1
This compound was obtained as a yellowish brown oil; H
[
NMR (400 MHz, CDCl ): δ 0.86-0.89 (m, 6H), 1.26-1.45 (m,
3
3
0H), 1.62-1.70 (m, 2H), 1.74-1.82 (m, 2H), 2.48 (s, 3H), 2.74 (t,
J = 8.0 Hz, 2H), 2.94 (t, J = 8.0 Hz, 2H), 7.40-7.45 (m, 2H), 7.72
s, 1H), 7.90 (d, J = 8.5 Hz, 1H); 13C NMR (100 MHz, CDCl ): δ
[
Tetrahedron Letters, 44, 2975 (2003).
(
[11a] For transition metal-catalyzed amine exchange reactions,
see: N. Yoshimura, I. Moritani, T. Shimamura and S.-I. Murahashi, J.
Am. Chem. Soc., 95, 3038 (1973); [b] S.-I. Murahashi, T. Hirano and T.
Yano, J. Am. Chem. Soc., 100, 348 (1978); [c] Y. Shvo and R. M. Laine,
J. Chem. Soc., Chem. Commun., 753 (1980); [d] B.-T. Khai, C. Concilio
and G. Porzi, J. Organomet. Chem., 208, 249 (1981); [e] B.-T. Khai, C.
Concilio and G. Porzi, J. Org. Chem., 46, 1759 (1981); [f] A. Arcelli,
B.-T. Khai and G. Porzi, J. Organomet. Chem., 231, C31 (1982); [g] S.-
I. Murahashi, K. Kondo and T. Hakata, Tetrahedron Letters, 23, 229
3
1
2
1
4.13, 21.50, 22.72, 29.38, 29.40, 29.55, 29.63, 29.66, 29.69,
9.72, 29.84, 30.00, 30.59, 31.96, 32.44, 125.75, 127.26, 128.20,
30.52, 134.04, 134.21, 135.11, 145.12, 161.28. Several peaks
are eclipsed.
Anal. Calcd. for C H N: C, 85.06; H, 11.74; N, 3.20. Found:
3
1 51
C, 85.26; H, 11.80; N, 3.29.
-Decyl-5,7-dimethyl-2-undecylquinoline (3x).
This compound was obtained as a yellowish brown oil; H
NMR (400 MHz, CDCl ): δ 0.86-0.89 (m, 6H), 1.26-1.48 (m,
3
(1982); [h]R. M. Laine, D. W. Thomas and L. W. Cary, J. Am. Chem.
1
Soc., 104, 1763 (1982); [i] C. W. Jung, J. D. Fellmann and P. E. Garrou,
Organometallics, 2, 1042 (1983); [j] S.-I. Murahashi, Angew. Chem.
Int. Ed. Engl., 34, 2443 (1995).
3
3
3
1
1
2
0H), 1.63-1.71 (m, 2H), 1.73-1.81 (m, 2H), 2.47 (s, 3H), 2.60 (s,
H), 2.77 (t, J = 8.0 Hz, 2H), 2.94 (t, J = 8.0 Hz, 2H), 7.10 (s,
[12] C. S. Cho, B. T. Kim, T. J. Kim and S. C. Shim, Chem.
1
3
H), 7.66 (s, 1H), 7.91 (s, 1H); C NMR (100 MHz, CDCl ): δ
Commun., 2576 (2001).
[13] C. S. Cho, B. T. Kim, H.-J. Choi, T.-J. Kim and S. C. Shim,
Tetrahedron, 59, 7997 (2003)
3
4.12, 18.50, 21.72, 22.71, 29.37, 29.39, 29.54, 29.62, 29.66,
9.71, 29.86, 29.98, 30.96, 31.93, 31.96, 32.75, 35.81, 114.67,
1
18.99, 124.51, 125.82, 128.34, 131.32, 132.77, 133.22, 137.93,
[14a] P. Friedländer, Chem. Ber., 15, 2572 (1882); [b] For a
review, see: C.-C. Cheng and S.-J. Yan, Org. Reactions, 28, 37 (1982).
147.02, 161.59. Several peaks are eclipsed.
[
15] S.-I. Murahashi, N. Yoshimura, T. Tsumiyama and T.
Kojima, J. Am. Chem. Soc., 105, 5002 (1983).
16a] Our recent examples for the direct application of nitroarenes
Anal. Calcd. for C H N: C, 85.07; H, 11.82; N, 3.10. Found:
3
2 53
C, 85.19; H, 11.91; N, 3.24.
[
to amine exchange reaction leading to indoles and quinolines: C. S.
Cho, T. K. Kim, S. W. Yoon, T.-J. Kim, S. C. Shim, Bull. Korean Chem.
Soc., 22, 545 (2001); [b] C. S. Cho, T. K. Kim, T.-J. Kim, S. C. Shim
and N. S. Yoon, J. Heterocyclic Chem., 39, 291 (2002); [c] C. S. Cho, T.
K. Kim, B. T. Kim, T.-J. Kim and S. C. Shim, J. Organomet. Chem.,
650, 65 (2002); [d] C. S. Cho, N. Y. Lee, H.-J. Choi, T.-J. Kim and S. C.
Shim, J. Heterocyclic Chem., 40, 292 (2003).
Acknowledgment.
The present work was supported by the Korea Research
Foundation Grant (KRF-2002-005-C00009). C.S.C. gratefully
acknowledges a MOE-KRF Research Professor Program (2001-
050-D00015).
[
17a] For transition metal-catalyzed reductive N-heterocyclization
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May-Jun 2004
Ruthenium-Catalyzed Formal Alkyl Group Transfer
429
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[
4
[
[