7414
J. Am. Chem. Soc. 2000, 122, 7414-7415
Table 1. Alkylation of Benzene with Various Olefinsa
Anti-Markovnikov Olefin Arylation Catalyzed by an
Iridium Complex
selectivityc
b
reaction
TOF
entry catalyst
olefin
time TNb (×10 s-1
-4
)
product
(%)
,
†
‡
,‡,§
Takaya Matsumoto,* Douglas J. Taube, Roy A. Periana,*
1
2
3
1
1
1
ethylene
ethylene
propylene 20 min 13
3 h
455
421
418
110
ethylbenzene
ethylbenzene
n-propylbenzene 61
cumene 39
iso-butylbenzene 82
tert-butylbenzene 18
1-phenylhexane
2-phenylhexane
k
l
‡
†
Henry Taube, and Hajime Yoshida
20 min 50
d
Central Technical Research Laboratory
Nippon Mitsubishi Oil Corporation
i-butenee
4
5
1
1
2 h
2
8
3
1-hexenef 20 min
69
69
31
0
8
Chidoricho, Nakaku, Yokohama
Kanagawa 231-0815, Japan
3-phenylhexane
Catalytica AdVanced Technologies, Inc.
h
6
1
methyl
20 min
5
39
3-PPAME
68
4
30 Ferguson DriVe
g
acrylate
Mountain View, California 94043
-PPAMEi
2
32
m
j
j
7
8
AlCl
3
ethylene
20 min 26
218
795
ethylbenzene
n-propylbenzene
cumene
d
ReceiVed March 22, 2000
AlCl3 propylene 20 min 95
0
100
0
66
34
j
1-hexenef 20 min 67
Significant efforts have been directed at homogeneous C-H
9
AlCl
3
554
1-phenylhexane
2-phenylhexane
bond activation of aromatic compounds by discrete transition
1
3-phenylhexane
metal complexes. In view of the unusual product selectivity
a
b
possible from reactions proceeding through the CH activation
reaction, exploitation of catalysis through this reaction has
attracted considerable attention. In the presence of an oxidant,
Pd complexes catalyze oxidative vinylation of benzene with
3
Reaction temperatures are 180 °C for 1 and 50 °C for AlCl . TN
c
and TOF are based on Ir for 1. Selectivity in mono-alkylated aromatic
compounds. d 0.78 Mpa of propylene, 1.96 Mpa N
. 0.20 Mpa of
e
2
f
i-butene 1.96 Mpa N
of benzene. 1.96 Mpa of N
containing 10.1 M of benzene. 1.96 Mpa of N
3
acid methyl ester. 2-Phenylpropionic acid methyl ester. AlCl was
2
. Benzene/1-hexene solution containing 8.8 M
g
2
2
. Benzene/methyl acrylate solution
h
ethylene to produce styrene or oxidative coupling of benzene to
. 3-Phenylpropionic
j
3
2
give biphenyl. Murai et al. has reported alkylations of aromatic
i
ketones by olefins. The reaction is catalyzed by Ru complexes
to afford products that are not easily obtainable by conventional
synthetic methods. In this system an acyl group is required to
activate the ortho C-H bonds of the aromatic ring for alkylation
k
conducted into an autoclave under N . l [ethylbenzene (EB)] ) 279
2
mM, [diethylbenzene (DEB)] ) 9 mM. [EB] ) 48 mM, [DEB] ) 2
mM. m [EB] ) 426 mM, [DEB] ) 20 mM.
4
to occur. Other related CH activation reactions of aromatics that
follow Markovnikov’s rule, producing branched alkylbenzenes
require the presence of activating functional groups are the
in nearly 100% selectivity.7
alkylation of pyridines and aromatic nitriles.5
Even when shape selective, acidic zeolites are employed for
Herein we report the novel, anti-Markovnikov, arylation of
olefins with benzene to produce straight-chain alkylbenzenes with
higher selectivity than the branched alkylbenzene. The reaction,
Friedel-Crafts alkylations, it is almost impossible to obtain
8
straight-chain alkylbenzene. Typically, to synthesize straight
chain alkyl aromatics, a combination of Friedel-Crafts acylation
and Clemenson reduction is employed. Using the reactions
described herein, it is possible to obtain the straight chain product
in one step using unactivated olefins and aromatics.
3
catalyzed by the binuclear Ir (III) complex, [Ir(µ-acac-O,O,C )-
3
, 1,6 is assumed to occur by the CH
(
acac-O,O)(acac-C )]
2
activation of the aromatic CH bonds. In contrast, conventional
Friedel-Crafts alkylation of aromatic compounds with olefins,
catalyzed by Lewis and Br o¨ nsted acid activation of the olefin,
For example, when benzene and 1 were heated in the presence
of ethylene at 180 °C for 3 h, ethylbenzene was obtained (TOF
-1
9
†
) 0.0421 s , TN ) 455; Table 1, entry 1). Alkylation of benzene
with propylene resulted in formation of n-propylbenzene and
cumene in 61 and 39% selectivities, respectively (Table 1, entry
Nippon Mitsubishi Oil Corporation.
‡
Catalytica Advanced Technologies, Inc.
§
University of Southern California, Department of Chemistry.
1) (a) Zhou, R.; Wang, C.; Hu, Y.; Flood, T. C. Organometallics 1997,
(
3). Showing the generality of the reaction and the preference for
1
6, 434. (b) Selmeczy, A. D.; Jones, W. D.; Osman, R.; Perutz, R. N.
Organometallics 1995, 14, 5677. (c) Meyer. T. Y.; Woerpel, K. A.; Novak,
B. M.; Bergman, R. G. J. Am. Chem. Soc. 1994, 116, 10290. (d) Jones, W.
D.; Hessell, E. T. J. J. Am. Chem. Soc. 1992, 114, 6087. (e) Boese, W. T.;
Goldman, A. S. Organometallics, 1991, 10, 782-786. (f) Flood, T. C. In
Electron Deficient Boron Carbon Clusters; Olah, G. A., Wade, K., William,
R. E., Eds.; Wiley: New York, 1991, pp 309-349. (g) Kozhevnikov, I. V.;
Kim, V. I.; Talzi, E. P.; Sidelnikov, V. N. J. Chem. Soc., Chem. Commun.
anti-Markovnikov additon, reaction with 1-hexene and isobutene
(Table 1, entries 5 and 4) resulted in 1-phenylhexane (69%
selectivity) and isobutylbenzene (82% selectivity), respectively.
As a comparison, using AlCl as a typical Friedel-Crafts catalyst,
3
only Markovnikov addition products were observed (Table 1,
entries 7, 8, and 9). Alkylation of toluene with ethylene gave
only m- and p-ethyl methylbenzene in 63 and 37% selectivity:
no ortho addition products were observed. Similarly ethylbenzene
gave m- and p-diethylbenzene in a 7:3 ratio, respectively. This
selectivity for meta and para substitution, presumably driven by
sterics, has also been observed in other CH activation systems.
For example, toluene is activated in the meta and para positions
1
985, 1392. (h) Helden, R. V.; Verberg, G. Rec. TraV. Chim. 1965, 84, 1263.
(
i) Gretz, E.; Oliver, T. F.; Sen, A. J. Am. Chem. Soc. 1987, 109, 8109. (j)
Hong, P.; Yamazaki, H. J. Mol. Catal. 1984, 26, 297. (k) Crabtree, R. H.
Chem. ReV. 1985, 85, 245.
(2) (a) Fujiwara, Y.; Moritani, I.; Danno, S.; Asano, R.; Teranishi, S. J.
Am. Chem. Soc. 1969, 91, 7166. (b) Taraban’ko, V. E.; Kozhevnikov, I. V.;
Matveev, K. I. Kinet. Katal. 1978, 19, 1160. (c) Heck, R. F. In Organic
Reactions; Adams, R. J., Eds.; Wiley: New York, 1982, pp 345-390.
(
3) (a) Iataaki, H.; Yoshimoto, H. J. Org. Chem. 1973, 38, 76. (b)
3 4
by OsH(Neopentyl)(PMe ) in statistical 2:1 ratio to produce
Rudenkov, A. I.; Mennenga, G. U.; Rachkovskaya, L. N.; Matveev, K. I.;
Kozhevnikov, I. V. Kinet. Katal. 1977, 18, 915.
(
4) (a) Murai, S.; Chatani, N.; Kakiuchi, F. Pure Appl. Chem. 1997, 69,
(7) Burgoyne, E. E. A Short Course in Organic Chemistry; McGraw-Hill
Book Co.: Singapore, 1985; pp 137-139.
(8) Cao, Y.; Kessas, R.; Naccache, C.; Taarit, Y. B. Appl. Catal. A 1999,
184, 231.
(9) In a typical reaction protocol, a 10 mL stainless autoclave, equipped
with a glass insert and a magnetic stir bar is charged with 3 mL of benzene
saturated with water and 1.0 mg of 1. The reactor is degassed with nitrogen,
pressurized with 1.96 Mpa of ethylene and heated to 180 °C with stirring for
3 h. The liquid phase was sampled and analyzed by GC (FID) and GC-MS
at the end of the reaction.
5
89. (b) Murai, S.; Kakiuchi, F.; Sekine, S.; Tanaka, Y.; Kamatani, A.; Sonoda,
M.; Chatani, N. Nature 1993, 366, 529. (c) Kakiuchi, F.; Sekine, S.; Tanaka,
Y.; Kamatani, A.; Sonoda, M.; Chatani, N.; Murai, S. Bull. Chem. Soc. Jpn.
1
1
995, 68, 62. (d) Trost, B. M.; Imi, K.; Davies, I. W. J. Am. Chem. Soc.
995, 117, 5371.
(5) (a) Lim, YG.; Han, J. S.; Koo, B. T.; Kang, J. B. Bull. Korean Chem.
Soc. 1999, 20, 1097. (b) Kakiuchi, F.; Sonoda, M.; Tsujimoto, T.; Chatani,
N.; Murai, S. Chem. Lett. 1999, 1083.
(
6) Bennett, M. A.; Mitchell, T. R. B. Inorg. Chem. 1976, 15, 2936.
1
0.1021/ja0009830 CCC: $19.00 © 2000 American Chemical Society
Published on Web 07/12/2000