Highly efficient gold(III)-catalyzed intermolecular hydroarylation of unactivated alkenes with arenes under mild conditions

Article abstract of DOI:10.1016/j.jorganchem.2008.07.035

A simple and efficient method for functionalization of electron-rich arenes and heteroarenes with unactivated alkenes by Au(III)-catalyzed intermolecular hydroarylation under mild reaction conditions was developed. This method features a short reaction time (5 h) under mild conditions and has a broad substrate scope, including electron-rich arenes and heteroarenes, terminal and internal substituted aryl alkenes, and unactivated aliphatic alkenes.

Full text of DOI:10.1016/j.jorganchem.2008.07.035

Journal of Organometallic Chemistry 694 (2009) 494–501
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Highly efficient gold(III)-catalyzed intermolecular hydroarylation of unactivated
alkenes with arenes under mild conditions
a
b
a,b,*
Ya-Ping Xiao , Xin-Yuan Liu , Chi-Ming Che
a
Shanghai–Hong Kong Joint Laboratory in Chemical Synthesis, Shanghai Institute of Organic Chemistry, The Chinese Academy of Sciences, 354 Feng Lin Road, Shanghai 200032, China
Department of Chemistry and Open Laboratory of Chemical Biology, The Institute of Molecular Technology for Drug Discovery and Synthesis, The University of Hong Kong,
b
Pokfulam Road, Hong Kong, China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 13 May 2008
Received in revised form 23 July 2008
Accepted 29 July 2008
Available online 5 August 2008
A simple and efficient method for functionalization of electron-rich arenes and heteroarenes with unac-
tivated alkenes by Au(III)-catalyzed intermolecular hydroarylation under mild reaction conditions was
developed. This method features a short reaction time (5 h) under mild conditions and has a broad sub-
strate scope, including electron-rich arenes and heteroarenes, terminal and internal substituted aryl
alkenes, and unactivated aliphatic alkenes.
Ó 2008 Elsevier B.V. All rights reserved.
Keywords:
Arenes
Gold(III)-catalyst
Intermolecular hydroarylation
Unactivated alkenes
1
. Introduction
Au(I) and Au(III) complexes have increasingly been used as cat-
efficiency and environmental friendliness [8–10]. In the literatures,
hydroarylations of styrene derivatives with electron-rich aryl and
heterocyclic compounds have also been carried out with FeCl
[11] Bi(OTf) [12], or BiCl [13] as the catalyst for the synthesis
3
alysts in a variety of organic transformations, and the majority of
such transformations draw on the propensity of gold ions to acti-
vate alkynes toward nucleophilic addition [1]. In recent years,
gold-catalyzed organic transformations have also been developed
into a number of protocols to activate C@C bonds toward nucleo-
philic attack, and indeed, gold-catalyzed inter- and intramolecular
addition of unactivated alkenes to oxygen- [2], nitrogen- [3], or
active methylene-nucleophiles [4] have been documented in the
literatures. However, to the best of our knowledge, there have been
few examples on gold-catalyzed intermolecular hydroarylation of
unactivated alkenes [5], which can be applied to a variety of al-
kenes and aryl substrates. Although Liu and co-workers have re-
ported the use of AuCl /AgOTf or triflic acid as the catalyst for
3
hydroarylation of alkenes, this reaction was confined to indole sub-
strates [6].
Intermolecular hydroarylation of alkenes is an efficient and
atom-economic approach to synthesize a variety of alkylated are-
nes and heteroarenes, which are important structural motifs com-
monly found in many pharmaceuticals, agro-, and fine chemicals
,
3
3
of a variety of 1,1-diarylalkanes. However, these reported intermo-
lecular hydroarylation reactions usually require high reaction tem-
perature (80–110 °C) and/or prolonged reaction time (ꢀ24 h).
Furthermore, the alkene substrates of most of the reported inter-
molecular hydroarylations are confined to styrene derivatives
[11–13]. Thus, a catalyst that induces addition of both aryl and het-
erocyclic compounds to both styrenes and aliphatic alkenes in a
relatively short reaction time at lower temperature would be
highly desirable. Owing to the ability of gold(I) and gold(III) to acti-
vate aryl C–H bonds [14], we envisioned that gold complexes
might be able to catalyze C–C bond formation through activation
of arenes toward attack by unactivated alkenes. As part of our pro-
gram to develop gold-catalyzed C–O, C–N, and C–C bond formation
reactions [15], herein we report a highly efficient gold(III)-cata-
lyzed intermolecular hydroarylation of unactivated alkenes with
arenes or heteroarenes under mild reaction conditions and have
extended the substrate scope of alkenes to those having different
steric and electronic properties.
[
7]. Transition metal catalysts for such transformation reactions
are of particular importance due to their high selectivity, synthetic
2
. Results and discussion
*
Corresponding author. Address: Shanghai–Hong Kong Joint Laboratory in
To identify optimal reaction conditions for gold-catalyzed
hydroarylation of alkenes, a number of Ag , Au , and Au catalysts
in different organic solvents at 50 °C were tested for the reaction of
Chemical Synthesis, Shanghai Institute of Organic Chemistry, The Chinese Academy
of Sciences, 354 Feng Lin Road, Shanghai 200032, China.
E-mail address: cmche@hku.hk (C.-M. Che).
I
I
III
0
022-328X/$ - see front matter Ó 2008 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2008.07.035

Y.-P. Xiao et al. / Journal of Organometallic Chemistry 694 (2009) 494–501
495
styrene (1A) with toluene (2a) (Table 1). The metal salts AgSbF
Au(OAc) , AuCl and Au(PPh )Cl failed to catalyze this reaction (Ta-
ble 1, entries 1–4). In the presence of 5 mol% of Au(PPh )Cl/AgSbF
or AuBr /AgSbF , reaction of 1A with 2a in dichloroethane for 5 h
6
,
Having established the optimal conditions, we next investigated
the effect of arenes in their reactions with styrene (1A) (Table 2). A
wide range of arenes including aryl and heterocyclic variants could
be used, leading to the formation of desired adducts in high yields
and good regioselectivities. Regardless of the substituent on the
aryl ring, arene derivatives furnished a variety of 1,1-diarylalkanes
in 58–96% yields (Table 2, entries 1–5). In all cases, the para-substi-
tuted product was obtained as the major product, except in the
case of benzene (2b) and p-xylene (2d). It should be noted that ste-
ric hindrance has little effect on this reaction. For instance, with
mesitylene (2f) as the substrate, the product 3Af was obtained in
a good yield (79%) under the same reaction conditions (Table 2, en-
try 6). This Au(III)-catalyzed reaction allows for the synthesis of
3
3
3
3
6
3
6
gave the corresponding product 3Aa in low yield (ꢀ30%) and poor
regioselectivity ((2–5):1) (Table 1, entries 5 and 6). To our delight,
3 6
using a combination of 5 mol% of AuCl and 15 mol% of AgSbF as a
catalyst, the hydroarylation product 3Aa was formed in 86% yield
with good regioselectivity (9:1) (Table 1, entry 7). A dramatic de-
crease in the yield of 3Aa was found when the amount of AgSbF
was reduced from 15 to 5 mol% (Table 1, entries 7–9). Other count-
6
À
À
À
eranions such as NO , BF , PF did not lead to hydroarylation
3
4
6
activity, perhaps due to their good binding ability to gold(III) ion
À
(
Table 1, entries 10–12). Noncoordinating anion such as SbF6
heteroarene derivatives. Treatment of thiophene (2g) with AuCl
3
/
was found to be the best counteranion for the reaction (Table 1, en-
try 7). The effect of solvent was also examined. Halogenated sol-
vent gave better results than non-halogenated solvents (Table 1,
entries 7 and 15–17), and the yield of 3Aa remained almost the
same under solvent-free conditions (Table 1, entry 18). The use
of an excess amount of 2a could effectively suppress some side
reactions, and the yield of 3Aa could be increased significantly
from 41% to 86% (Table 1, entries 7, 19, and 20). When a 10:1 ratio
of 2a and 1A was used, the formation of by-products became neg-
ligible and the yield of 3Aa was the best. After optimization of reac-
AgSbF furnished a 4.5:1 mixture of the regioisomeric product
6
3Ag in 87% yield (Table 2, entry 7). This contrasts to the formation
of similar heteroarenes in <60% yields from thiophene in other sim-
ilar transition metal-catalyzed reactions [11–13]. This protocol can
be scaled up to gram-scale synthesis of arene derivatives. A cou-
pling reaction of 1A (10 mmol) with 2a (100 mmol) in the presence
3 6
of 2 mol% of AuCl and 6 mol% of AgSbF afforded 3Aa (1.6 g) in
78% yield for a reaction time of 7 h (Table 2, entry 8).
Following the successful gold(III)-catalyzed hydroarylation of
styrene (1A) using various arenes, we decided to examine a series
of unactivated alkenes in their reactions with anisole (2c) (Table 3).
Generally, the reaction worked well for a range of styrene deriva-
tives with substituents having different steric and electronic prop-
erties, and coupling of anisole (2c) with styrenes 1B-G bearing
electron-rich p-Me substituent and electron-withdrawing halo-
gen-substitutents (F, Cl, Br) gave the corresponding adducts in
tion conditions, the protocol with 5 mol% of AuCl
3
and 15 mol% of
AgSbF
yield.
6
at 50 °C in dichloroethane for 5 h gave the product in 86%
8
5–90% yields (Table 3, entries 1–6). Interestingly, the Au(III)-cat-
Table 1
a
Optimization of reaction conditions
alyzed reactions of disubstituted aryl alkenes also afforded the
highly substituted arenes in good yields (Table 3, entries 8–10).
For example, the styrene derivative 1I having geminal substituent
was transformed to the corresponding product 3Ic containing a
quaternary carbon center in 89% yield (Table 3, entry 8). Using in-
dene (1J) and dihydronaphthalene (1K) as the substrates, aryl-
dihydroindene and tetrahydronaphthalene derivatives 3Jc and
catalyst
+
o
solvent, 50 C, 5 h
1
A
2a
3
Aa
Entry Catalyst
Solvent
Selectivity Yield (%)b
3
Kc, the key moieties of which are commonly found in different
b
(
p-:o-)
products such as agrochemicals and fungicides, and useful com-
pounds such as nafenopin, a peroxisome proliferator [12], were ob-
tained in excellent yields (Table 3, entries 9 and 10).
In the literatures, most addition of arenes to alkenes was con-
ducted with aryl alkenes [11–13]. However, this gold(III)-catalyzed
hydroarylation reaction could also be applicable to unactivated ali-
phatic alkenes. Norbornene (1L) underwent hydroarylation, pro-
ducing exo-addition product 3Lc stereoselectively in 93% yield,
albeit with a low regioselectivity (1:1.1) (Table 3, entry 11). When
unactivated 2-methyl-2-butene (1M) and 2,3-dimethyl-2-butene
1
15 mol% AgSbF
5 mol% Au(OAc)
5 mol% AuCl
5 mol% Au(PPh
5 mol% Au(PPh
5 mol% AuBr
5 mol% AuCl
5 mol% AuCl
5 mol% AuCl
5 mol% AuCl
5 mol% AuCl
5 mol% AuCl
5 mol% AuCl
5 mol% AuCl
5 mol% AuCl
5 mol% AuCl
5 mol% AuCl
5 mol% AuCl
5 mol% AuCl
5 mol% AuCl
6
ClCH
ClCH
ClCH
ClCH
ClCH
ClCH
ClCH
ClCH
ClCH
ClCH
ClCH
ClCH
ClCH
ClCH
CH
c-Hexane
THF
Toluene
ClCH
ClCH
2
2
2
2
2
2
2
2
2
2
2
2
2
2
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
CH
2
2
2
2
2
2
2
2
2
2
2
2
2
2
Cl
Cl
Cl
Cl
–
–
–
–
Trace
Trace
Trace
Trace
41
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
3
3
3
)Cl
3
)Cl/5 mol% AgSbF
/15 mol% AgSbF
6
Cl 2:1
Cl 5:1
Cl 9:1
Cl 9:1
Cl 9:1
3
6
6
6
33
86
c
3
/15 mol% AgSbF
/10 mol% AgSbF
/5 mol% AgSbF
/15 mol% AgNO
/15 mol% AgBF
/15 mol% AgPF
/15 mol% AgOTf
/15 mol% AgClO
/15 mol% AgSbF
/15 mol% AgSbF
/15 mol% AgSbF
/15 mol% AgSbF
/15 mol% AgSbF
/15 mol% AgSbF
3
3
3
3
3
3
3
3
3
3
3
3
3
24
19
Trace
Trace
Trace
27
6
0
1
2
3
4
5
6
7
8
9
0
3
Cl
Cl
Cl
–
–
–
4
6
(
(
1N) were used as the substrates in their reactions with anisole
2c) under the same conditions, alkylated arenes 3Mc and 3Nc
Cl 9:1
Cl 7:1
4
6
6
6
6
6
6
51
64
d
were obtained in 95% and 93% yields, respectively, with excellent
regioselectivities (>20:1) (Table 3, entries 12 and 13). The yield
of 3Nc remained almost the same upon decreasing catalyst loading
from 5 to 1 mol% (Table 3, entry 13). It is interesting that 3Nc could
also be obtained by coupling of 3,3-dimethyl-1-butene (1O) with
2
Cl
2
10:1
–
–
Trace
Trace
e
9:1
88
f
2
CH
CH
2
Cl 9:1
Cl 9:1
55
g
2
2
41
1
1
c (Table 3, entry 14). This may be due to in situ conversion of
O to 1N via a gold(III)-catalyzed methyl group migration reaction
a
Reaction conditions: 0.5 mmol of styrene, 5 mmol of toluene, 12 mL of solvent,
0 °C, 5 h.
5
b
Yield and selectivity determined by 1H NMR (internal standard:
[16], and the 1N in situ coupled with 1c to give 3Nc. Under similar
conditions, gold-catalyzed couplings of a series of unactivated ali-
phatic cycloalkenes (1P-S) with anisole were accomplished to give
the corresponding products 3Pc-Sc in 59–93% yields (Table 3, en-
tries 15–18).
For previously proposed gold(III)-catalyzed intermolecular
hydroarylation of dienes with phenols in gold(III)-catalyzed
phenol-diene annulations [5], the reported mechanism includes
trimethyl(phenyl)silane).
c
Yield of isolated product is based on 1A.
Reaction conditions: 0.5 mmol of styrene, 12 mL of CH Cl , 40 °C, 5 h.
2 2
Reaction conditions: 0.5 mmol of styrene, 12 mL of toluene, 50 °C, 5 h.
Reaction conditions: 0.5 mmol of styrene, 3 mmol of toluene, 12 mL of solvent,
d
e
f
5
5
0 °C, 5 h.
g
Reaction conditions: 0.5 mmol of styrene, 2 mmol of toluene, 12 mL of solvent,
0 °C, 5 h.

4
96
Y.-P. Xiao et al. / Journal of Organometallic Chemistry 694 (2009) 494–501
Table 2
Scope of arenes of the intermolecular hydroarylation of styrene (1A)a
5
mol% AuCl /15 mol% AgSbF6
3
+
ClCH CH Cl, 50 °C
R1
2
2
R1
1
A
2
a-g
3
Aa-Ag
Entry
1
Arene
Selectivity (p-:o-)b
Major product
Yield (%)c
86
9:1
Ph
2
a
3
Aa
2d
–
78
Ph
Ph
2
b
3Ab
3
5.0:1
96 (91e)
OMe
Ph
OMe
2
c
3
Ac
4
5
–
58
79
Ph
2
d
2
3
Ad
>20:1
Ph
Ph
e
3
Ae
6
–
79
2
f
3
Af
7
4.5:1
87
78
S
S
Ph
2
g
3
Ag
8f
9:1
Ph
2
a
3
Aa
a
Reaction conditions: 0.5 mmol of styrene, 5 mmol of arene, 12 mL of solvent, 50 °C, 5 h.
Selectivity determined by H NMR.
Yield of isolated products is based on 1A.
Benzene was used as solvent.
Reaction conditions: 1 mmol of styrene, 10 mmol of anisole, 1 mol% of catalyst loading, 24 mL of solvent, 50 °C, 7 h.
Reaction conditions: 1A (10 mmol), 2a (100 mmol), 2 mol% of catalyst loading.
b
c
d
e
f
1

Y.-P. Xiao et al. / Journal of Organometallic Chemistry 694 (2009) 494–501
497
Table 3
Scope of unactivated alkenes of the intermolecular hydroarylation
a
Entry
1
Alkene
Selectivity (p-:o-)b
Major product
Yieldc (%)
86
5.3:1
1
B
MeO
3
Bc
2
3
4
4.4:1
1.6:1
2.0:1
90
88
85
F
1
C
MeO
MeO
F
F
3
Cc
F
1
D
3
Dc
F
F
1
E
MeO
3
Ec
5
6
1.8:1
5.4:1
87
90
Cl
Br
Cl
Br
1
F
MeO
MeO
3
Fc
1
G
3
Gc
Hc
7
8
7.5:1
78
89
1
H
MeO
3
>20:1
Ph
Ph
Ph
Ph
1
I
MeO
3
Ic
9
7.0:1
98
OMe
1
J
3
Jc
(continued on next page)

4
98
Y.-P. Xiao et al. / Journal of Organometallic Chemistry 694 (2009) 494–501
Table 3 (continued)
Entry
Alkene
Selectivity (p-:o-)b
Major product
Yieldc (%)
97
1
0
4.9:1
OMe
1
K
3
Kc
1
1
1
2
1:1.1
93
95
1
L
MeO
3Lc
>20:1
1
M
MeO
3
Mc
1
3
4
>20:1
>20:1
93 (90d)
1
N
MeO
3
Nc
Nc
1
79
1
O
MeO
MeO
3
1
1
5
6
2.4:1
1.8:1
59
85
1
P
3
Pc
1
Q
MeO
MeO
3
Qc
1
1
7
8
1.6:1
1.0:1
90
93
1
R
3
Rc
Cis-
1
S
MeO
3
Sc
a
Reaction conditions: 0.5 mmol of alkene, 5 mmol of anisole, 12 mL of solvent, 50 °C, 5 h.
Selectivity determined by 1H NMR.
Yield of isolated products is based on 1.
b
c
d
Reaction conditions: 1 mmol of alkene, 10 mmol of anisole, 24 mL of solvent, 1 mol% of catalyst loading, 50 °C, 7 h.

Y.-P. Xiao et al. / Journal of Organometallic Chemistry 694 (2009) 494–501
499
coordination of a diene double bond to Au(III), followed by forma-
tion of a C–Au bond through intermolecular addition of the C–H
bond, with subsequent protonolysis of the C–Au bond to give the
hydroarylation intermediate [5]. A similar mechanism as depicted
in Scheme 1 can be proposed for the catalytic hydroarylation of
unfunctionalized alkenes reported herein. Another mechanism,
which could not be excluded, involves the metalation of an arene
by cationic gold(III) to form an arylgold(III) intermediate and reac-
tion of the arylgold(III) intermediate with alkene to form the
hydroarylation product [14b,17].
added into the solution and the solution was heated to 50 °C. Al-
kene (0.5 mmol) dissolved in dichloroethane (8 mL) was intro-
duced into the mixture of reaction system by syringe pump over
4 h under 50 °C. The mixture was stirred at 50 °C for additional
1 h, and the solvent was removed under reduced pressure. The
residuum was subjected to flash chromatography with silica gel
to give the product.
4.2.1. 1-Methyl-4-(1-phenylethyl)benzene (3Aa) [18]
1
Colorless oil. H NMR (300 MHz, CDCl
3
/TMS): d 7.30–7.11 (m,
9
H), 4.12 (q, J = 7.2 Hz, 1H), 2.31 (s, 3H), 1.62 (d, J = 7.2 Hz, 3H);
IR (neat): 3084, 2966, 2928, 2873, 1602, 1513, 1494, 1452, 1374,
3
. Conclusion
À1
+
8
22, 722, 761, 699 cm ; MS (EI): m/z = 196([M ], 37), 181(100),
1
65(38), 166(32), 182(16), 77(13), 89(12), 178(9).
In summary, we have developed a simple and efficient method
for the functionalization of arenes and heteroarenes with product
yields up to 98% and good regioselectivities under mild reaction
conditions. This method features a short reaction time (5 h) under
mild conditions and a broad substrate scope, including electron-
rich arenes and heteroarenes, terminal and internal substituted
aryl alkenes, and unactivated aliphatic alkenes.
4
.2.2. 1,1-Diphenylethane (3Ab) [19]
Colorless oil. H NMR (300 MHz, CDCl
0H), 4.15 (q, J = 7.5 Hz, 1H), 1.64 (d, J = 7.5 Hz, 3H); IR (neat):
1
3
/TMS): d 7.31–7.12 (m,
1
3
À1
206, 2962, 2928, 1602, 1495, 1448, 767, 701 cm ; MS (EI): m/
+
z = 182([M ], 36), 167(100), 165(40), 152(19), 115(19), 77(18),
66(16), 168(15).
1
4
. Experimental
4
.2.3. 1-Methoxy-4-(1-phenylethyl)benzene (3Ac) [20]
1
Colorless oil. H NMR (300 MHz, CDCl
H), 6.83 (m, d, J = 8.1 Hz, 2H), 4.57 (q, J = 7.2 Hz, 1H), 3.78 (s,
3
/TMS): d 7.30À7.13 (m,
4.1. General
7
3
1
1
H), 1.61 (d, J = 7.2 Hz, 3H); IR (neat): 3067, 2966, 1612, 1512,
All reagents were obtained commercially and used without fur-
À1
+
245, 1178, 1028, 833, 699 cm ; MS (EI): m/z = 212([M ], 41),
ther purification unless otherwise noted. All experiments were car-
ried out under an inert atmosphere of Argon in the dark. All
anhydrous solvents used in the reactions were dried and freshly
97(100), 91(34), 165(24), 153(20), 152(16), 77(15), 198(15).
4
.2.4. 1,4-Dimethyl-2-(1-phenylethyl)benzene (3Ad) [21]
distilled. NMR spectra were recorded in CDCl
00 spectrometer at 25 °C with TMS as an internal standard. Mass
spectra were obtained on a HP5989A spectrometer (EI) or Agilent
973N MSD spectrometer (EI). IR spectra were recorded, using
KBr discs, on a Bio-Rad FTS-185 spectrometer.
3
on a Varian Mercury
1
Colorless oil. H NMR (300 MHz, CDCl
3
/TMS): d 7.30–7.23 (m,
3
2
H), 7.18–7.17 (m, 3H), 7.03 (m, 1H), 7.03–6.93 (m, 2H), 4.28 (q,
J = 7.2 Hz, 1H), 2.32 (s, 3H), 2.18 (s, 3H), 1.59 (d, J = 7.2 Hz, 3H);
IR (neat): 3025, 2967, 2929, 2873, 1602, 1495, 1451, 1377, 1158,
1
5
À1
+
031, 810, 699 cm ; MS (EI): m/z = 210([M ], 42), 195(100),
1
65(32), 180(28), 196(19), 178(18), 179(16), 77(15).
4.2. General procedure for gold(III)-catalyzed intermolecular
hydroarylation
4
.2.5. 1,2-Dimethyl-4-(1-phenylethyl)benzene (3Ae) [11]
Colorless oil. H NMR (300 MHz, CDCl /TMS): d 7.31–7.15 (m,
3
H), 7.07–7.04 (m, 1H), 7.00–6.95 (m, 2H), 4.09 (q, J = 7.2 Hz,
1
3 6
AuCl (7.6 mg, 0.025 mmol) and AgSbF (25.6 mg, 0.075 mmol)
were added into dichloroethane (4 mL) under Argon. The mixture
was stirred at room temperature for 2 h. Arene (5 mmol) was
5
1
2
3
H), 2.15 (s, 6H), 1.61 (d, J = 7.2 Hz, 3H); IR (neat): 3026, 2968,
À1
+
931, 1602, 1504, 1451, 823, 699 cm ; MS (EI): m/z = 210([M ],
7), 195(100), 165(30), 180(24), 196(17), 178(16), 179(14), 89(14).
R2
4.2.6. 1-(2,4,6-Trimethylphenyl)-1-phenylethane (3Af) [13]
1
3
Colorless oil. H NMR (300 MHz, CDCl /TMS): d 7.28–7.16 (m,
R1
R1
5H), 6.82 (s, 2H), 4.63 (q, J = 7.2 Hz, 1H), 2.26 (s, 3H), 2.11 (s, 6H),
1.65 (d, J = 7.2 Hz, 3H); IR (neat): 3002, 2965, 2930, 1611, 1511,
R2
À1
+
1
427, 1036, 833, 816, 751 cm ; MS (EI): m/z = 224([M ], 43),
[Au]
R
2
09(100), 179(26), 178(20), 210(18), 194(17), 115(17), 193(14).
4
.2.7. 2-(1-Phenylethyl)thiophene (3Ag) [22]
H+
R2
1
3
Colorless oil. H NMR (300 MHz, CDCl /TMS): d 7.31–7.22 (m,
5
H), 7.15 (m, 1H), 6.97–6.92 (m, 1H), 6.83 (m, 1H), 4.35 (q,
[Au]
1[Au]
J = 7.5 Hz, 1H), 1.70 (d, J = 7.5 Hz, 3H); IR (neat): 3064, 3028,
R
2
6
1
968, 2929, 2872, 1602, 1494, 1452, 1375, 1272, 1027, 851,
R1
À1
+
98 cm
; MS (EI): m/z = 188([M ], 46), 173(100), 129(14),
R2
74(13), 128(9), 171 (9), 77(8), 111(7).
R
4
.2.8. 1-(1-(4-Methoxyphenyl)ethyl)-4-methylbenzene (3Bc) [12]
Colorless oil. H NMR (300 MHz, CDCl /TMS): d 7.15–7.05 (m,
3
1
6
2
1
H), 6.83–6.81 (m, 2H), 4.07 (q, J = 7.2 Hz, 1H), 3.78 (s, 3H),
H+
.30 (s, 3H), 1.59 (d, J = 7.2 Hz, 3H); IR (neat): 3063, 2955, 2927,
À1
601, 1494, 1453, 1376, 1026, 754, 699 cm ; MS (EI): m/
R
+
z = 226([M ], 33), 211(100), 105(23), 212(17), 165(13), 152(10),
Scheme 1.
153(10), 91(9).

5
00
Y.-P. Xiao et al. / Journal of Organometallic Chemistry 694 (2009) 494–501
4
.2.9. 1-Fluoro-4-(1-(4-methoxyphenyl)ethyl)benzene (3Cc) [12]
4.2.16. 1-(4-Methoxyphenyl)-2,3-dihydro-1 H-indene (3Jc) [12]
1
1
Colorless oil. H NMR (300 MHz, CDCl
3
/TMS): d 7.18–7.10 (m,
3
Colorless oil. H NMR (300 MHz, CDCl /TMS): d 7.30–7.26 (m,
4
H), 6.98–6.92 (m, 2H), 6.83 (d, J = 7.8 Hz, 2H), 4.09 (q,
1H), 7.20–7.10 (m, 4H), 6.96–6.93 (m, 1H), 6.87–6.84 (m, 2H),
4.29 (t, J = 8.1 Hz, 1H), 3.80 (s, 3H), 3.04–2.88 (m, 2H), 2.61–2.50
(m, 1H), 2.08–1.98 (m, 1H); IR (neat): 3067, 3020, 2954, 2836,
2064, 1612, 1585, 1512, 1478, 1457, 1441, 1344, 1303, 1245,
1178, 1107, 1038, 829, 763 cm ; MS (EI): m/z = 224([M ], 100),
173(86), 193(66), 115(53), 223(52), 188(41), 127(37), 116(32).
J = 7.2 Hz, 1H), 3.78 (s, 3H), 1.59 (d, J = 7.2 Hz, 3H); IR (neat):
3
1
3
1
036, 2965, 2932, 2875, 1886, 1608, 1584, 1509, 1463, 1303,
À1
+
247, 1180, 1159, 1035, 831, 753 cm ; MS (EI): m/z = 230([M ],
1), 215(100), 171(20), 216(16), 183(14), 109(12), 170(11),
72(8).
À1
+
4
.2.17. 1-(4-Methoxyphenyl)-1,2,3,4-tetrahydronaphthalene (3Kc)
[12]
Colorless oil. 1H NMR (300 MHz, CDCl
7.08–7.00 (m, 3H), 6.86–6.81 (m, 3H), 4.07 (t, J = 6.0 Hz, 1H), 3.79
s, 3H), 2.94–2.80 (m, 2H), 2.17–2.09 (m, 1H), 1.88–1.74 (m, 3H);
4
.2.10. 1-Fluoro-3-(1-(4-methoxyphenyl)ethyl)benzene (3Dc)
1
3
Colorless oil. H NMR (300 MHz, CDCl /TMS): d 7.24–7.17 (m,
3
/TMS): d 7.12 (m, 2H),
1
4
H), 7.12–7.10 (m, 2H), 6.98–6.96 (m, 1H), 6.90–6.81 (m, 4H),
1
3
.08 (q, J = 7.2 Hz, 1H), 3.75 (s, 3H), 1.58 (d, J = 7.2 Hz, 3H);
): d 164.51, 161.26, 157.96, 149.49, 149.39,
37.72, 129.71, 129.60, 128.41, 123.19, 123.15, 114.47, 114.19,
C
(
NMR (75 MHz, CDCl
3
IR (neat): 3003, 2922, 2851, 1612, 1585, 1514, 1491, 1454, 1302,
1
1
1
1
1
7
1
À1
263, 1241, 1176, 1110, 1032, 835, 817, 771, 741 cm ; MS (EI):
13.80, 113.37, 112.87, 112.59, 65.42, 55.14, 43.66, 43.64, 21.83,
9.05; IR (neat): 2968, 2934, 2837, 1614, 1590, 1512, 1490, 1448,
375, 1303, 1247, 1180, 1144, 1124, 1034, 909, 872, 832, 786,
+
m/z = 238([M ], 32), 130(100), 129(30), 115(28), 165(22), 179(20),
78(19), 210(17).
1
À1
+
53, 693, 559 cm ; MS (EI): m/z = 230([M ], 47), 215(100),
4
.2.18. exo-2-(o-Methoxyphenyl)bicyclo[2.2.1]heptane (3Lc) [25]
09(37), 183(21), 171(19), 216(16), 170(13), 18(9). HRMS(EI)
1
Colorless oil. H NMR (300 MHz, CDCl
3
/TMS): d 7.15–7.05 (m,
Calcd. For [C15
H15OF] 230.1107, Found 230.1103.
2
H), 6.93–6.81 (m, 2H), 3.82 (s, 3H), 3.00–2.95 (m, 1H), 2.34–2.31
(
m, 2H), 1.82–1.74 (m, 1H), 1.67–1.12 (m, 7H); IR (neat): 2952,
4
.2.11. 1-Fluoro-2-(1-(4-methoxyphenyl)ethyl)benzene (3Ec) [12]
2
8
1
870, 2834, 1612, 1583, 1513, 1491, 1249, 1180, 1108, 1037,
1
Colorless oil. H NMR (300 MHz, CDCl
3
/TMS): d 7.21–7.02 (m,
À1
+
24, 752 cm ; MS (EI): m/z = 202([M ], 3), 149(100), 121(28),
6
H), 6.85–6.82 (m, 2H), 4.43 (q, J = 7.2 Hz, 1H), 3.78 (s, 3H), 1.60
47(20), 91(16), 190(11), 150(11), 134(8), 77(8).
(
d, J = 7.2 Hz, 3H); IR (neat): 2969, 2934, 2877, 2837, 1612, 1584,
À1
1
513, 1489, 1455, 1247, 1227, 1180, 1035, 832, 755 cm ; MS
4
.2.19. 1-Methoxy-4-tert-pentylbenzene (3Mc) [26]
+
(
2
EI): m/z = 230([M ], 12), 115(100), 57(86), 114(51), 215(35),
16(25), 89(15), 132(12).
1
3
Colorless oil . H NMR (300 MHz, CDCl /TMS): d 7.24 (d, J =
9
7
.0 Hz, 2H), 6.84 (d, J = 9.0 Hz, 2H), 3.79 (s, 3H), 1.61 (q, J =
.2 Hz, 1H), 1.26 (s, 6H), 0.67 (t, J = 7.2 Hz, 3H); IR (neat): 3103,
4
.2.12. 1-Chloro-3-(1-(4-methoxyphenyl)ethyl)benzene (3Fc) [12]
3063, 3029, 2965, 2878, 2836, 1612, 1582, 1515, 1465, 1443,
1385, 1363, 1305, 1251, 1185, 1117, 1039, 1010, 828, 807, 775,
649 cm ; MS (EI): m/z = 178([M ], 13), 149(100), 121(31),
1
3
Colorless oil. H NMR (300 MHz, CDCl /TMS): d 7.18–7.07 (m,
À1
+
6
H), 6.85–6.83 (m, 2H), 4.07 (q, J = 6.9 Hz, 1H), 3.78 (s, 3H), 1.59
(
1
d, J = 6.9 Hz, 3H); IR (neat): 2967, 2934, 2836, 1612, 1595, 1512,
150(14), 109(10), 91(9), 163(6), 77(5).
À1
478, 1464, 1303, 1248, 1180, 1035, 832, 786, 695 cm ; MS (EI):
+
m/z = 246([M ], 1), 57(100), 115(96), 114(50), 216(19), 89(15),
32(12), 63(10), 116(10).
4.2.20. 2,3-Dimethyl-3-(4-methoxyphenyl)butane (3Nc) [27]
1
1
Colorless oil. H NMR (300 MHz, CDCl
3
/TMS): d 7.24 (d,
J = 8.4 Hz, 2 H), 6.83 (d, J = 8.4 Hz, 2H), 3.81 (s, 3H), 1.90–1.81 (m,
H), 1.22 (s, 6H), 0.75 (d, J = 6.6 Hz, 6H); IR (neat): 2963, 2876,
1
4
.2.13. 1-Bromo-4-(1-(4-methoxyphenyl)ethyl)benzene (3Gc) [23]
Colorless oil. H NMR (300 MHz, CDCl /TMS): d 7.39 (d,
3
1
2835, 1612, 1582, 1514, 1486, 1442, 1378, 1296, 1253, 1186,
À1
1
149, 1118, 1086, 1039, 1011, 830, 808, 762, 559 cm ; MS (EI):
J = 8.4 Hz, 2H), 7.12–7.09 (m, 4H), 6.83 (d, J = 8.4 Hz, 2H), 4.06 (q,
J = 7.2 Hz, 1H), 3.78 (s, 3H), 1.58 (d, J = 7.2 Hz, 3H); IR (neat):
2
1
z = 290([M ], 36), 275(100), 277(99), 292(35), 152(29), 153(22),
1
+
m/z = 192([M ], 3.8), 148(100), 121(19), 150(11), 91(11), 109(8),
7(6), 147(5).
7
967, 2933, 2835, 1611, 1513, 1484, 1404, 1378, 1303, 1244,
À1
177, 1072, 1028, 1008, 842, 782, 742, 545 cm ; MS (EI): m/
+
4.2.21. 1-Cyclopentyl-4-methoxybenzene (3Pc) [28]
1
Colorless oil. H NMR (300 MHz, CDCl
3
/TMS): d 7.16 (d,
65(20), 276(17).
J = 8.7 Hz, 2H), 6.83 (d, J = 8.7 Hz, 2H), 3.79 (s, 3H), 2.94 (m, 1H),
2
2
1
1
.08–2.00 (m, 2H), 1.84–1.50 (m, 6H). IR (neat): 2997, 2954,
4
.2.14. 2-(1-(4-Methoxyphenyl)ethyl)naphthalene (3Hc) [24]
869, 2835, 1612, 1584, 1514, 1464, 1442, 1304, 1246, 1179,
1
Colorless oil. H NMR (300 MHz, CDCl
3
/TMS): d 7.80–7.68 (m,
À1
+
109, 1040, 826, 808, 753 cm ; MS (EI): m/z = 176([M ], 47),
5
4
H), 7.45–7.34 (m, 2H), 7.19–7.16 (m, 2H), 6.85–6.82 (m, 2H),
.27 (q, J = 6.9 Hz, 1H), 3.78 (s, 3H), 1.70 (d, J = 6.9 Hz, 3H); IR
47(100), 121(42), 91(34), 134(28), 148(19), 119(11), 77(9).
(
1
(
8
neat): 3055, 2965, 2932, 2835, 1633, 1610, 1584, 1511, 1463,
4
.2.22. 1-Cyclohexyl-4-methoxybenzene (3Qc) [29]
À1
440, 1303, 1246, 1179, 1034, 857, 832, 820, 751, 551 cm ; MS
1
3
Colorless oil. H NMR (300 MHz, CDCl /TMS): d 7.13 (d,
+
EI): m/z = 262([M ], 1), 57(100), 115(97), 114(50), 216(16),
9(15), 74(13), 132(12), 63(11).
J = 6.9 Hz, 2H), 6.84 (d, J = 6.9 Hz, 2H), 3.78 (s, 3H), 2.50–2.38 (m,
1
2
751 cm ; MS (EI): m/z = 190([M ], 57), 147(100), 121(61),
149(51), 91(37), 134(25), 77(15), 148(14).
H), 1.90–1.69 (m, 5H), 1.46–1.16 (m, 5H). IR (neat): 2996, 2926,
852, 1611, 1583, 1514, 1449, 1285, 1178, 1105, 1040, 825, 796,
À1
+
4
.2.15. 1-(1,1-Diphenylethyl)-4-methoxybenzene (3Ic) [12]
1
Yellow oil. H NMR (300 MHz, CDCl
3
/TMS): d 7.29–7.20 (m, 6H),
7
3
2
1
.11–7.10 (m, 4H), 7.00 (d, J = 9.0 Hz, 2H), 6.80 (d, J = 9.0 Hz, 2H),
.80 (s, 3H), 2.17 (s, 3H); IR (neat): 3062, 3014, 2975, 2933,
834, 1959, 1888, 1609, 1596, 1512, 1490, 1461, 1442, 1376,
4.2.23. 1- Cycloheptyl-4-methoxy-benzene (3Rc)
1
Colorless oil. H NMR (300 MHz, CDCl /TMS): d 7.12 (d,
3
À1
294, 1248, 1183, 1029, 913, 855, 809, 788, 765, 700 cm ; MS
J = 8.7 Hz, 2H), 6.83 (d, J = 8.7 Hz, 2H), 3.79 (s, 3H), 2.66–2.60 (m,
+
13
(
EI): m/z = 288([M ], 4), 247(100), 262(41), 57(38), 115(37),
1H), 1.92–1.53 (m, 12H). C NMR (75 MHz, CDCl ): d 157.36,
3
2
15(31), 202(26), 141(25), 273(23).
142.28, 127.46, 113.59, 55.20, 46.16, 37.03, 27.90, 27.10; IR (neat):

Y.-P. Xiao et al. / Journal of Organometallic Chemistry 694 (2009) 494–501
501
3
1
7
9
064, 3030, 2925, 2855, 2836, 1890, 1600, 1586, 1512, 1492, 1463,
(f) C.F. Bender, R.A. Widenhoefer, Org. Lett. 8 (2006) 5303;
g) N. Morita, N. Krause, Eur. J. Org. Chem. 20 (2006) 4634.
4] (a) X. Yao, C.-J. Li, J.Am. Chem. Soc. 126 (2004) 6884;
b) R.-V. Nguyen, X.-Q. Yao, D.S. Bohle, C.-J. Li, Org. Lett. 7 (2005) 673.
[5] R.-V. Nguyen, X. Yao, C.-J. Li, Org. Lett. 8 (2006) 2397.
(
328, 1291, 1241, 1176, 1100, 1054, 1035, 949, 819, 751,
[
À1
+
40 cm
1(54), 134(35), 119(23), 205(16), 122(12). HRMS(EI) Calc. For
20O]: 204.1514. Found: 204.1513.
; MS (EI): m/z = 204([M ], 87), 147(100), 121(68),
(
[
[
6] M.M. Rozenman, M.W. Kanan, D.R. Liu, J. Am. Chem. Soc. 129 (2007) 14933.
[
C
14
H
7] (a) G.A. Olah, R. Krishnamurti, G.K.S. Prakash, A solution to the crisis, in: B.M.
Trost, I. Fleming (Eds.), Friedel-Crafts Alkylations in Comprehensive Organic
Synthesis, vol. 8, Pergamon Press, Oxford, 1991, pp. 293–339;
4.2.24. 1- Cyclooctyl-4-methoxy-benzene (3Sc) [30]
1
(b) C. Liu, C.F. Bender, X. Han, R.A. Widenhoefer, Chem. Commun. (2007) 3607.
8] (a) G. Dyker, E. Muth, A.S.K. Hashmi, L. Ding, Adv. Synth. Catal. 345 (2003)
Colorless oil. H NMR (300 MHz, CDCl
3
/TMS): d 7.11 (d,
[
J = 8.1 Hz, 2H), 6.82 (d, J = 8.1 Hz, 2H), 3.78 (s, 3H), 2.75–2.69 (m,
1
247;
(b) M. Bandini, A. Melloni, A. Umani-Ronchi, Angew. Chem., Int. Ed. 43 (2004)
50.
1
2
1
1
H), 2.08–2.01 (m, 1H), 1.83–1.53 (m, 13H). IR (neat): 2923,
854, 1600, 1585, 1492, 1465, 1447, 1290, 1241, 1184, 1131,
055, 1034, 751, 738 cm
47(100), 121(76), 91(54), 134(53), 119(32), 259(20), 258(20).
5
À1
+
[9] (a) I. Shimizu, K.M. Khien, M. Nagatomo, T. Nakajima, A. Yamamoto, Chem.
Lett. (1997) 851;
; MS (EI): m/z = 218([M ], 55),
(b) D. Karshtedt, A.T. Bell, T.D. Tilley, Organometallics 23 (2004) 4169;
(
(
c) G. Bhalla, J. Oxgaard, W.A. Goddard III, R.A. Periana, Organometallics 24
2005) 3229.
4.3. Procedure for large scale hydroarylation
[
10] (a) R.K. Thalji, K.A. Ahrendt, R.G. Bergman, J.A. Ellman, J. Am. Chem. Soc. 123
2001) 9692;
(
AuCl (60.6 mg, 0.2 mmol) and AgSbF
were added into dichloroethane (20 mL) under Argon. The mixture
was stirred at room temperature for 2 h. Toluene (9.32 g,
3
6
(206.2 mg, 0.6 mmol)
(b) K.A. Ahrendt, R.G. Bergman, J.A. Ellman, Org. Lett. 5 (2003) 1301.
11] J. Kischel, I. Jovel, K. Mertins, A. Zapf, M. Beller, Org. Lett. 8 (2006) 19.
12] M. Rueping, B.J. Nachtsheim, T. Scheidt, Org. Lett. 8 (2006) 3717.
13] H.-B. Sun, B. Li, R. Hua, Y. Yin, Eur. J. Org. Chem. (2006) 4231.
[
[
[
1
00 mmol) was added into the solution and the solution was
[14] (a) For selected examples of gold-catalyzed hydroarylation, see M.T. Reetz, K.
Sommer, Eur. J. Org. Chem. (2003) 3485;
heated to 50 °C. Styrene (1.092 g, 10.48 mmol) was dissolved in
dichloroethane (40 mL) and introduced into the mixture of reac-
tion system by syringe pump over 6 h under 50 °C. The mixture
was stirred at 50 °C for additional 1 h, and the solvent was re-
moved under reduced pressure. The residuum was subjected to
flash chromatography with silica gel to give the product (1.610 g,
(
(
b) Z. Shi, C. He, J. Org. Chem. 69 (2004) 3669;
c) C. Nevado, A.M. Echavarren, Chem. Eur. J. 11 (2005) 3155;
(d) A.S.K. Hashmi, M.C. Blanco, E. Kurpejovi c´ , W. Frey, J.W. Bats, Adv. Synth.
Catal. 348 (2006) 709;
(
(
e) A.S.K. Hashmi, M.C. Blanco, Eur. J. Org. Chem. (2006) 4340;
f) A.S.K. Hashmi, P. Haufe, C. Schmid, A.R. Nass, W. Frey, Chem. Eur. J. 12
(2006) 5376;
g) P.Y. Toullec, E. Genin, L. Leseurre, J.-P. Genêt, V. Michelet, Angew. Chem.,
Int. Ed. 45 (2006) 7427;
h) N. Marion, P. Carlqvist, R. Gealageas, P. de Frémont, F. Maseras, S.P. Nolan,
Chem. Eur. J. 13 (2007) 6437;
i) H.C. Shen, Tetrahedron 64 (2008) 3885.
(
8
.20 mmol, yield: 78%).
(
Acknowledgments
(
[
[
15] (a) Recent work on gold catalysis developed by our group C.-Y. Zhou, P.W.H.
Chan, C.-M. Che, Org. Lett. 8 (2006) 325;
This work was supported by The University of Hong Kong (Uni-
versity Development Fund), the Hong Kong Research Grants Coun-
cil (HKU 7012/05P), and the University Grants Committee of the
Hong Kong SAR of China (Area of Excellence Scheme, AoE/P-10/
(b) V.K.-Y. Lo, Y. Liu, M.-K. Wong, C.-M. Che, Org. Lett. 8 (2006) 1529;
(c) X.-Y. Liu, C.-H. Li, C.-M. Che, Org. Lett. 8 (2006) 2707;
(
(
(
d) X.-Y. Liu, P. Ding, J.-S. Huang, C.-M. Che, Org. Lett. 9 (2007) 2645;
e) C.-Y. Zhou, C.-M. Che, J. Am. Chem. Soc. 129 (2007) 5828;
f) V.K-Y. Lo, M.-K. Wong, C.-M. Che, Org. Lett. 10 (2008) 517;
0
1). Y.-P. Xiao thanks the Croucher Foundation of Hong Kong for
a postgraduate studentship.
(g) X.-Y. Liu, C.-M. Che, Angew. Chem., Int. Ed. 47 (2008) 3805.
16] (a) For acid-catalyzed methyl group migration of 3,3-dimethyl-1-butene see
W.M. Schubert, P.H. LeFevre, J. Am. Chem. Soc. 94 (1972) 1639;
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(
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(
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