Coupling of arylboronic acids with benzyl halides or mesylates without adding transition metal catalysts

Article abstract of DOI:10.1016/j.tet.2016.10.031

We report herein a transition-metal-free coupling reaction of arylboronic acids with benzyl halides and mesylates for the construction of C(sp²)[sbnd]C(sp³) bonds. A unique feature of this coupling reaction is the formation regioisomers in some cases. Mechanistic studies suggest that this reaction may proceed via an unprecedented Friedel–Crafts-type reaction pathway under base conditions with the assistance of boronic acid moiety.

Full text of DOI:10.1016/j.tet.2016.10.031

Accepted Manuscript
Coupling of arylboronic acids with benzyl halides or mesylates without adding
transition metal catalysts
Guojiao Wu, Shuai Xu, Yifan Deng, Chaoqiang Wu, Xia Zhao, Wenzhi Ji, Yan Zhang,
Jianbo Wang
PII:
S0040-4020(16)31065-1
10.1016/j.tet.2016.10.031
TET 28172
DOI:
Reference:
To appear in: Tetrahedron
Received Date: 24 August 2016
Revised Date: 12 October 2016
Accepted Date: 14 October 2016
Please cite this article as: Wu G, Xu S, Deng Y, Wu C, Zhao X, Ji W, Zhang Y, Wang J, Coupling of
arylboronic acids with benzyl halides or mesylates without adding transition metal catalysts, Tetrahedron
(2016), doi: 10.1016/j.tet.2016.10.031.
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Graphical Abstract
Coupling of Arylboronic Acids with Benzyl Halides or
Mesylates without Adding Transition Metal Catalysts
Leave this area blank for abstract info.
Guojiao Wu, Shuai Xu, Yifan Deng, Chaoqiang Wu, Xia Zhao, Wenzhi Ji, Yan Zhang and Jianbo
Wang*

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1
Tetrahedron
journal homepage: www.elsevier.com
Coupling of Arylboronic Acids with Benzyl Halides or Mesylates without Adding
Transition Metal Catalysts
Guojiao Wu, Shuai Xu, Yifan Deng, Chaoqiang Wu, Xia Zhao, Wenzhi Ji, Yan Zhang and Jianbo Wang*
Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871,
People’s Republic of China
ARTICLE INFO
ABSTRACT
We report herein a transition-metal-free coupling reaction of arylboronic acids with benzyl
halides and mesylates for the construction of C(sp2)-C(sp3) bonds. A unique feature of this
coupling reaction is the formation regioisomers in some cases. Mechanistic studies suggest that
this reaction may proceed via an unprecedented Friedel–Crafts-type reaction pathway under base
conditions with the assistance of boronic acid moiety.
Article history:
Received
Received in revised form
Accepted
Available online
2009 Elsevier Ltd. All rights reserved.
Keywords:
Cross-Coupling
Transition-metal-free reaction
Arylboronic acids
Benzyl halides
Diarylmethanes
1. Introduction
transition-metal-free Suzuki-type coupling of allylic bromides
with arylboronic acids.7 Later Ueda and Ryu reported transition-
Suzuki-Miyaura cross-couplings of organoboronic acids with
organohalides or pseudohalides have well-established as one of
the most versatile and widely utilized reactions for the
construction of C-C bonds.1 In the past decades, the scope of
Suzuki-Miyaura coupling has been significantly broadened. One
of the recent advances is the Pd-catalyzed cross-coupling reaction
of benzylic substrates with arylboronic acids for the synthesis of
diarylmethanes,2 which are a type of important molecules found
applications in various areas.3 For example, Molander and Elia
reported the Pd-catalyzed cross-coupling of benzyl halides with
potassium aryltrifluoroborates.2d Kumano and Yokogi developed
Pd-catalyzed cross-coupling of benzyl carbonates with
arylboronic acids.2h
metal-free coupling reaction of arylpropargylic bromides with
aryl- and alkenylboronic acids.8 We report herein our study on a
Suzuki-Miyaura cross-couplings of arylboronic acids and benzyl
halides or mesylates under the conditions that no transition metal
catalyst was added.9 The reaction is likely a transition-metal-free
process based on the mechanistic experiments and ICP-MS
analysis.
Scheme 1. Cross-coupling of Arylboronic Acids with Benzylic
Halides or Pseudohalides
On the other hand, in recent years transition-metal-free
coupling reactions have attracted considerable attentions due to
the obvious advantages of avoiding using precious transition
metals such as palladium.4 In 2003, a transition-metal-free
Suzuki-type coupling reactions of arylboronic acid with aryl
o
halides at 150 C under microwave irradiation was reported by
Leadbeater,5 who later corrected that the coupling was owing to
trace amount of palladium contaminants (down to a level of 50
ppb) found in commercially available Na2CO3 which was used as
the base in their coupling reaction. In 2012, Inamoto and Doi
reported a coupling reaction of aryliodides with arylboronic acids
without adding any transition metal catalysts.6 They suggested
that the coupling reaction is likely a transition-metal-free process
based on the results of ICP-MS analysis. In the same year, the
groups of Scrivanti and Ueda-Ryu independently disclosed
The initial benchmark was the reaction carried out with 4-
methylbenzyl chloride 1a and 4-bromophenyl boronic acid 2a
(Table 1). Our original expectation is that a carbene species may
be generated by treatment of 1a with a strong base, which may
further react with 2a to realize a transition-metal-free coupling.10
With sodium hydride as the base and toluene as the solvent, the

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2
Tetrahedron
coupling product 3a was indeed observed (20% NMR yield)
With the optimized the reaction conditions, we proceeded to
examine the substrate scope of the reaction. As shown in Scheme
2, the reaction with a series of substituted arylboronic acids
worked smoothly to afford the corresponding cross-coupling
products. The reaction also worked with heterocyclic boronic
acids (3g, 3h). In addition to the anticipated coupling products,
the formation of minor regioisomers was observed in many cases,
but the ratio varied considerably. For example, the reactions of 4-
methylbenzyl chloride with 4-anisylboronic acid afforded 3c as
the only product. However, the reactions with 4-tert-
butylphenylboronic acid and 2-tolylboronic acid gave two
isomeric products in each case, with ratio of 6:1 (3d) and 9:1 (3e)
respectively. In the case of 3-furylboronic acid and 2-
furylboronic acid both reactions gave the product with
benzylation at C2-position as the major one. Similar results were
observed in the reaction of 2 and 3-thienylboronic acid (3h). The
reaction of cinnamyl bromide with 4-bromophenylboronic acid
also afforded the corresponding coupling product 3l, but with low
yield.
(Table 1, entry 1). Notably, in addition to 3a we could also
observe the formation of regioisomer 3a' by careful inspection of
the 1H NMR spectra of the crude product (3a:3a' > 20:1).
Inspired by this initial result, we decided to optimize the reaction
conditions. No reaction occurred when sodium hydride was
removed from the system (Table 1, entry 2). Changing the
solvent from toluene to dioxane resulted in the formation of only
trace
amount
of
the
product
3a,
while
with
(trifluoromethyl)benzene as the solvent the reaction was
improved (Table 1, entries 2, 3). As the base plays crucial role in
this reaction, we next screened various bases. K2CO3 and K3PO4
gave comparable results as NaH, while Cs2CO3 and Et3N failed
to afford the product 3a (Table 1, entries 5-8). Interestingly,
lithium tert-butoxide afforded improved result with 73% isolated
yield (Table 1, entry 9). In contrast, the reaction with potassium
tert-butoxide gave only trace product 2a, instead SN2 substitution
product of benzyl chloride was predominant (Table 1, entry 10).
With lithium tert-butoxide as the base, several other solvents
were examined again and no improvement could be achieved
(Table 1, entries 11-13). Besides, the yield diminished when the
reaction temperature was changed from 100 oC to 80 oC (Table 1,
entry 14). Finally, by lowing the loading of lithium tert-butoxide
from 3.0 to 2.0 equiv, the product 3a could be isolated in 78%
yield (Table 1, entry 16).
Scheme 2. Reaction of Benzyl Chlorides with Arylboronic Acidsa
Table 1. Optimization of the Reaction Conditionsa
Entry
Base (equiv)
Solvent
Yield(%)b
1
2
3
4
5
6
7
8
9
NaH (3.0)
--
NaH (3.0)
NaH (3.0)
K2CO3 (3.0)
K3PO4 (3.0)
Cs2CO3 (3.0)
Et3N (3.0)
PhMe
PhMe
dioxane
PhCF3
PhCF3
PhCF3
PhCF3
PhCF3
PhCF3
PhCF3
DMF
20
0
trace
43(35)c
32
46
0
0
LiOtBu (3.0)
KOtBu (3.0)
LiOtBu (3.0)
LiOtBu (3.0)
LiOtBu (3.0)
LiOtBu (3.0)
LiOtBu (3.0)
LiOtBu (2.0)
(73)c
trace
0
10
11
12
13
14
15
16
aReaction conditions: The solution of 1 (0.5 mmol), 2 (1.0 mmol)
and LiOtBu (1.0 mmol) in PhCF3 (2 mL) was stirred at 100 oC for
10-24 h. All the yields refer to isolated products. Isomeric ratio
DCE
(68)c
0
MeCN
PhCF3
PhCF3
PhCF3
27d
(41)e
(78)c
1
b
was determined by H NMR spectra. The yield in bracket refers
c
to the reaction with 4-methylbenzyl bromide. The reaction was
with cinnamyl bromide.
aIf not otherwise noted, the reaction was carried out with 1a (0.25
mmol), 2a (0.5 mmol) in solvent (1 mL) at 100 oC with the base.
bThe yields were estimated by the 1H NMR with nitromethane as
the internal standard. The formation of 3a' was observed. The
Notably, the reaction of benzyl chloride with phenylboronic 2b
under the optimized reaction conditions gave the coupling
product 5a in only 10% yield (Scheme 3). We then proceeded to
examine the reaction with various benzyl alcohol derivatives.
Compared with benzyl chloride, benzyl mesylate and tosylate
showed high reactivity and gave the coupling product in
improved yields. However, the reaction with benzyl
trifluoroacetate failed to give the coupling product. With benzyl
mesylate as the substrate, the reaction can be further optimized
by changing LiOtBu to KF, the solvent from PhCF3 to DCE, and
c
ratio of 3a:3a' is >20:1. The reaction was carried out with 1a
(0.5 mmol), 2a (1.0 mmol) in solvent (2 mL) at 100 oC with the
base. The isolated yields are indicated in the brackets. dThe
o
reaction was carried out at 80 C. eThe reaction was carried out
with 1a (0.25 mmol) and 2a (0.37 mmol).
o
o
lowering the reaction temperature from 100 C to 80 C. Under

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such conditions, the coupling product 5a could be obtained in
77% isolated yield.
Scheme 3. Comparison of the Reactivity of Benzyl Chloride
with Benzyl Alcohol Derivativesa
aReaction was carried out with 4 (0.25 mmol), 2k (0.5 mmol),
LiOtBu (0.5 mmol) in PhCF3 (1 mL) at 100 oC for 10 h.
Under the modified conditions, a series of arylboronic acids
and benzyl mesylates were subjected to the reaction. As shown in
Scheme 4, the reaction with a series of benzyl mesylates worked
smoothly to afford the corresponding coupling products. Notably,
the reaction also worked well with ortho-substituted mesylates,
indicating that the reaction does not significantly affected by
steric effects (5k-r). It should be noted that benzyl mesylate
bearing electron withdrawing group such as nitro, ester also
gave satisfactory results with modified reaction conditions
(LiOtBu, 100 oC) (5z, 6a and 6b).
Different from metal-catalyzed coupling reaction, the reaction
with 3-iodobenzyl mesylate gave the products with iodine
remained intact (5t-v). The reaction with allyl phosphate and
propargyl mesylate also afforded the desired products with
excellent yields (6c and 6d). The reaction with phenethyl
mesylate gave the coupling products, albeit with a lower yield
(6e). Interestingly, the reaction of benzyl mesylates and
arylboronic acid showed different regioselectivity as compared
with the reaction with benzyl halides in the cases that regio-
isomers were formed in the reaction. For the reactions with
benzyl chlorides, the benzylation took place in ipso- and meta-
position of the boron, while the benzylation took place in suit- or
ortho-position of the boron when using benzyl mesylates or
phosphates as the substrates.
To gain insights into this reaction, mechanistic experiments
have been carried out. Considering the previous reports that the
coupling of benzyl substrates with arylboronic acids took place
with palladium as the catalyst,2 a control experiments were first
carried out by using 5 mol% Pd(PPh3)4 as the additional
palladium catalyst introduced into the reaction system. However,
the yield of the coupling product was actually droped from 77%
to 63% (eq. 1). Thus, the addition of Pd(0) catalyst to the
reaction system did not improve the efficiency of the coupling
reaction.
aReaction conditions: the solution of 4a-m (0.75 mmol), 2 (0.5
mmol) and KF (1.0 mmol) in DCE (2 mL) was stirred at 70 oC for
10-24 h. Isolated yields. All the yields refer to isolated products.
Isomeric ratio was determined by 1H NMR spectra. bIn the cases
when there was regio-isomers, the boronic acids used and the
c
product ratio were indicated below the products. The yield in
bracket refers to the reaction with LiOtBu as the base instead of
d
e
KF. Phosphates were used instead of mesylate. Reaction was
conducted with 4 (0.5 mmol), 2 (1.0 mmol) and LiOtBu (1.0
mmol) in DCE (2 mL) at 100 oC.
(1)
are involved in the coupling reaction. The transition-metals
analyzed included palladium, copper,11 nickel,12 iron13 and
cobalt,14 which are commonly used as the catalysts in the
reactions of benzyl halides with organic boronic acids or
Grignard reagents. The results are summarized in Table 2.
Palladium and cobalt are not detected in the substrates, and
copper and nickel both are less than 0.5 ppm, and the iron has a
highest concentration in KF is 6.252 ppm. The very low
concentration level of transition metal in this reaction system
seems not likely to catalyzed the coupling reaction.
Moreover, the formation of regioisomers in many cases is not
in accordance with the traditional palladium-catalyzed Suzuki-
Miyaura coupling. To further clarify whether the coupling
reaction is a transition-metal-free process or it is actually
catalyzed by trace amount of trasition-metal contaminents,5 the
coupled plasma mass spectroscopy (ICP-MS) was used to
analyze the contents of the transition-metals in the reagents that
Scheme 4. Reaction of Benzyl Mesylates with Arylboronic Acidsa
Table 2. ICP-MS analysis of trace transition metalsa
c
Metal
LiOtBu (99%)b
PhB(OH)2
KF (99.99%)d
Pd
< 10-3
< 10-3
< 10-3
3.165  10-1
3.175  10-1
8.878  10-3
Cu

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4
Tetrahedron
1.845  10-1
1.046
1.554  10-1
1.747
4.646  10-1
6.252
Ni
Fe
Co
< 10-3
< 10-3
< 10-3
a1 unit = 1 g/g (ppm); the detection limit is 10-9 (ppb).
bLiOtBu (99% purity) was purchased from Energy Chemical.
cPhB(OH)2 was purchased from Alfa. dKF (99.99% purity)
was purchased from Acros.
Further experiments were then carried out to confirm if the
reaction involves cations as the possible intermediates. Thus, N-
methylindole was used as the electron-rich aromatic compound to
capture the possible cation intermediate under the standard
condition. 3-Benzyl-N-methylindole was observed as major
product in 35% NMR yield. However, in the absence of boronic
acid or lithium t-butoxide, only trace 3-benzyl-N-methylindole
was detected (Scheme 5, b). These results suggest that cation is
generated with the assistance of boronic acid and lithium t-
butoxide. Finally, 12-crown-4 was added into the system to
chelate the lithium. Under such conditions, no reaction was
observed (Scheme 5, c). This result indicates that lithium ion is
also essential for the reaction.
2. Summary
In summary, we have reported a reaction of benzyl halides or
mesylates with arylboronic acids without adding any transition-
metal catalysts. The reaction is most likely a transition-metal-
free process and mechanistic studies suggest that carbon cations
may be involved in the reaction pathway. Thus, this coupling
reaction may be an unusual Friedel-Crafts-type reaction under
basic conditions.
Scheme 5. Mechanistic Experiments
3. Experimental section
3.1 General
All solvents were distilled to remove water over Na or CaH2 prior
to use, except the PhCF3. All the coupling reactions were carried
out under nitrogen. Column chromatograph was performed on
1
200-300 mesh silica gal. H NMR and 13C NMR spectral were
recorded at 400 MHz and 101 MHz with 400MHz WB Solid-
State NMR Spectrometer (or Bruker AVANCE III spectrometer)
using CDCl3 as solvent. Chemical shifts are reported in ppm. The
IR spectra were recorded with a Thermo Electron Corporation
Nicolet AVATAR 300 FT-IR spectrometer. Mass spectra were
measured on Bruker Apex IV FTMS spectrometer. EI-MS were
obtained on MS5975C. The reagents used in this study were
purchased from commercial suppliers and were used without
further purification.
Based on these experimental results and the recent reports on
the reaction of organoboron reagents with stable carbon cations,15
the following mechanistic hypothesis is proposed for this
transformation (Scheme 6). First, the boronic acid reacts with the
metal salt to form complex I. The lithium ion activates the C-X
bond of benzyl substrate to generate ion pair II. Subsequently,
Friedel-Craft reaction pathway via the cyclo-members ring via
the interaction between the X and benzyl cation leads to the
formation of the coupling product and its regioisomer. However,
further rigorous mechanistic studies are necessary to substantiate
this mechanistic hypothesis.
General Procedure for Reaction of Benzyl Halides with
Arylboronic Acids
Arylboronic acid (1.0 mmol), LiOtBu (1.0 mmol) was added to a
Schlenk tube. The tube was charged with nitrogen and then
PhCF3 (2 mL) and benzyl chloride (0.5 mmol) were added. The
reaction mixture was stirred at 100 oC for 24 h. After the mixture
was cooled down to room temperature, solvent was removed
under reduced pressure to leave a crude product. The crude
product was purified by column chromatography on silica gel,
eluting with petroleum ether to afford the coupling product.
1-bromo-4-(4-methylbenzyl)benzene16 and 1-bromo-2-(4-methyl
benzyl)benzene17 (>20:1) (3a). Following the general procedure,
the crude residue was purified by column chromatography on
silica gel (eluted with petroleum ether) to afford pure 3a as a
colourless oil (102 mg, 78%, 110 mg, 84%). 1H NMR (400 MHz,
CDCl3) δ 7.38 (d, J = 8.4 Hz, 2H), 7.46-7.42 (m, 1H), 7.32 (t, J =
7.4 Hz, 2H), 7.26-7.24 (m, 1H), 7.18 (d, J = 7.3 Hz, 2H), 7.10-
7.03 (m, 6H), 4.07 (s, 0.05H), 3.88 (s, 2H), 2.31 (s, 3H); 13C
NMR (101 MHz, CDCl3) δ 140.4, 137.4, 135.8, 131.5, 130.6,
129.3, 128.8, 119.9, 40.9, 21.0. The carbons of the minor product
Scheme 6. Mechanistic Hypothesis

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5
did not show on the 13C NMR spectra due to the low
concentration and limited scanning times.
(m, 4H), 6.38 (dd, J = 3.1, 1.9 Hz, 1H), 5.99 (dd, J = 3.1, 0.7
Hz, 1H), 3.93 (s, 2H), 3.73 (s, 0.1H), 2.32 (s, 3H); 13C NMR (101
MHz, CDCl3) δ 154.9, 141.4, 136.0, 135.1, 129.2, 128.6, 110.2,
106.0, 34.1, 21.1. The other carbons of the minor product did not
show on the 13C NMR spectra due to the low concentration and
limited scanning times.
1-Benzyl-4-methylbenzene (3b)17 Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
1
afford pure 3b as a colorless oil (70 mg, 77%). H NMR (400
MHz, CDCl3) δ 7.26-7.25 (m, 2H), 7.19-7.16 (m, 3H), 7.08 (s,
4H), 3.93 (s, 2H), 2.30 (s, 3H); 13C NMR (101 MHz, CDCl3) δ
141.5, 138.1, 135.6, 129. 2, 128.9, 128.9, 128.5, 126.0, 41.6,
21.1.
2-(4-Methylbenzyl)furan21 and 3-(4-methylbenzyl)furan (5:2) (3g).
Following the general procedure, the crude residue was purified
by column chromatography on silica gel (eluted with petroleum
1
ether) to afford 3g as a colourless oil (34 mg, 39%). H NMR
(400 MHz, CDCl3) δ 7.34 (s, 0.3H), 7.31 (s, 0.7H), 7.20 (s, 0.3H),
7.11 (s, 3H), 7.10 (s, 1H), 6.28-6.27 (m, 0.7H), 6.23 (s, 0.3H),
5.98 (d, J = 3.1 Hz, 0.7H), 3.92 (s, 1.5H), 3.72 (s, 0.5H), 2.32 (s,
3H); 13C NMR (101 MHz, CDCl3) δ 154.9, 143.0 (minor), 141.4,
139.5 (minor), 137.3 (minor), 136.0, 135.6 (minor), 135.1, 129.2,
129.1 (minor), 128.6, 128.4 (minor), 124.5 (minor), 111.2
(minor), 110.2, 106.0, 34.1, 30.8 (minor), 21.0.
1-methoxy-4-(4-methylbenzyl)benzene (3c)17 Following the
general procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
1
afford 3c as a colorless oil (78 mg, 74%). H NMR (400 MHz,
CDCl3) δ 7.10-7.04 ( m, 6H), 6.81 (d, J = 8.6 Hz, 2H), 3.88 (s,
2H), 3.77 (s, 3H), 2.30 (s, 3H); 13C NMR (101 MHz, CDCl3) δ
157.9, 138.6, 135.4, 133.6, 129.8, 129.1, 128.7, 113.9, 55.3, 40.6,
21.0.
2-(4-Methylbenzyl)thiophene22
and
3-(4-methylbenzyl)
thiophene22 (3:2) (3h). Following the general procedure, the
crude residue was purified by column chromatography on silica
gel (eluted with petroleum ether) to afford pure 3h as a pale
1-(tert-Butyl)-4-(4-methylbenzyl)benzene17 and 1-(tert-butyl)-2-
(4-methylbenzyl)benzene (6:1) (3d). Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
1
yellow oil (42 mg, 45%). H NMR (400 MHz, CDCl3) δ 7.23-
7.21 (m, 0.5H), 7.14-7.09 (m, 4.5H), 6.91-6.89 (m, 1.4H), 6.78-
6.77 (m, 0.6H), 4.10 (s, 1.2H), 3.93 (s, 0.8H), 2.31 (s, 3H); 13C
NMR (101 MHz, CDCl3) δ 144.5 (minor), 141.9, 137.6, 137.4
(minor), 136.1 (minor), 135.7, 129.3, 129.2 (minor), 128.7,
128.5, 128.5 (minor), 126.8 (minor), 125.6, 125.0 (minor), 123.9
(minor), 121.1, 36.2, 35.7 ( minor), 21.1, 21.1 (minor).
1
afford 3d as a colorless oil (83 mg, 70%). H NMR (400 MHz,
CDCl3) δ 7.29 (d, J = 8.3 Hz, 2H), 7.12 (s, 1H), 7.10-7.08 (m,
5H), 3.94 (s, 0.3H), 3.91 (s, 1.8H), 1.30 (s, 1.3H), 1.29 (s, 7.8H);
13C NMR (101 MHz, CDCl3) δ 148.7, 138.4, 138.3, 135.5, 129.1,
128.8, 128.4, 125.3, 41.0, 34.4, 31.4, 21.0. The carbons of the
minor product did not show on the 13C NMR spectra due to the
low concentration and limited scanning times.
2-(4-Methylbenzyl)thiophene22
with
3-(4-methylbenzyl)
thiophene22 (5:4) (3h). Following the general procedure, the
crude residue was purified by column chromatography on silica
gel (eluted with petroleum ether) to afford 3h as a pale yellow oil
1-Methyl-2-(4-methylbenzyl)benzene18
and
1-methyl-4-(4-
methylbenzyl)benzene18 (9:1) (3e). Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
1
(41 mg, 44%). H NMR (400 MHz, CDCl3) δ 7.24-7.22 (m,
0.6H), 7.15-7.09 (m, 4.4H), 6.92-6.89 (m, 1.5H), 6.79-6.78 (m,
0.5H), 4.11 (s, 1.1H), 3.93 (s, 0.9H), 2.32 (s, 3H); 13C NMR (101
MHz, CDCl3) δ 144.5 (minor), 141.8, 137.6, 137.4 (minor), 136.0
(minor), 135.6, 129.2, 129.2 (minor), 128.6, 128.5, 128.5
(minor), 126.8 (minor), 125.6, 125.0 (minor), 123.8 (minor),
121.1, 36.1, 35.7 (minor), 21.1, 21.0 (minor).
1
afford 3e as a colourless oil (44 mg, 45%). H NMR (400 MHz,
CDCl3) δ 7.15-7.12 (m, 3H), 7.09-7.06 (m, 3H), 7.01 (d, J = 8.0
Hz, 2H), 3.94 (s, 1.8H), 3.90 (s. 0.2H), 2.31 (s, 3.3H), 2.24 (s,
2.7H); 13C NMR (101 MHz, CDCl3) δ 139.2, 138.4 (minor),
137.3, 136.6, 135.5 (minor), 135.4, 130.3, 129.9, 129.1 (minor),
128.8 (minor), 128.7, 126.4, 126.0, 41.1 (minor), 39.0, 21.0, 19.7.
The carbons of the minor product did not show on the 13C NMR
spectra due to the low concentration and limited scanning times.
1-Benzyl-4-bromobenzene17 with 1-benzyl-2-bromobenzene23
(17:1) (3i). Following the general procedure, the crude residue
was purified by column chromatography on silica gel (eluted
with petroleum ether) to afford 3i as a colourless oil (82 mg,
1-(4-Methylbenzyl)naphthalene19
and
2-(4-methylbenzyl)
1
naphthalene20 (8:1) (3f). Following the general procedure, the
crude residue was purified by column chromatography on silica
gel (eluted with petroleum ether) to afford 3f as a colourless oil
(70 mg, 60%). 1H NMR (400 MHz, CDCl3) δ 8.00-7.98 (m, 1H),
7.85-7.83 (m, 1H), 7.74 (d, J = 8.3 Hz, 1H), 7.45-7.38 (m, 3H),
7.28-7.27 (m, 1H), 7.11-7.05 (m, 4H), 4.40 (s, 1.8H), 4.09 (s.
0.2H), 2.31 (s, 0.4H), 2.29 (s, 2.6H); 13C NMR (101 MHz,
CDCl3) δ 137.6, 136.9, 135.5, 134.0, 132.2, 129.2 (minor), 129.2,
128.9 (minor), 128.7, 128.7, 128.1 (minor), 127.6 (minor), 127.6
(minor), 127.3, 127.1, 127.0 (minor), 126.0, 125.6, 125.6, 125.3
(minor), 124.3, 41.7 (minor), 38.6, 21.0. The other carbons of the
minor product did not show on the 13C NMR spectra due to the
low concentration and limited scanning times.
63%). H NMR (400 MHz, CDCl3) δ 7.38 (d, J = 8.3 Hz, 2H),
7.29-7.26 (m, 2H), 7.21-7.13 (m, 3H), 7.04 (d, J = 8.3 Hz, 2H),
4.11 (s, 0.1H), 3.91 (s, 1.9H); 13C NMR (101 MHz, CDCl3) δ
140.5, 140.2, 131.6, 130.7, 128.9, 128.6, 126.4, 120.0, 41.3. The
carbons of the minor product did not show on the 13C NMR
spectra due to the low concentration and limited scanning times.
1-(4-Bromobenzyl)-2-methylbenzene (3j).17 Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
afford 3j as a colourless oil (106 mg, 81%). 1H NMR (400 MHz,
CDCl3) δ 7.26 (d, J = 8.4 Hz, 2H), 7.06-7.03 (m, 3H), 6.97-6.95
(m, 1H), 6.87 (d, J = 8.3 Hz, 2H), 3.81 (s, 2H), 2.10 (s, 3H); 13C
NMR (101 MHz, CDCl3) δ 139.5, 138.3, 136.6, 131.5, 130.5,
130.5, 130.0, 126.8, 126.2, 119.8, 39.0, 19.7.
2-(4-Methylbenzyl)furan21 and 3-(4-methylbenzyl)furan (16:1)
(3g). Following the general procedure, the crude residue was
purified by column chromatography on silica gel (eluted with
petroleum ether) to afford 3g as a colourless oil (37 mg, 43%). 1H
NMR (400 MHz, CDCl3) δ 7.31 (d, J = 1.0 Hz, 1H), 7.12-7.10
4-(4-Bromobenzyl)-1,1'-biphenyl24 with 4-(2-bromobenzyl)-1,1'-
biphenyl (19:1) (3k). Following the general procedure, the crude
residue was purified by column chromatography on silica gel

ACCEPTED MANUSCRIPT
6
Tetrahedron
(eluted with petroleum ether) to afford 3k as a white solid (87
8.3 Hz, 2H), 5.19 (s, 2H), 2.95 (s, 3H); 13C NMR (101 MHz,
mg, 54%). IR (film) 3026, 1486, 1011, 760, 737 cm-1; H NMR
(400 MHz, CDCl3) δ 7.56-7.54 (m, 2H), 7.49 (d, J = 8.2 Hz, 2H),
7.41-7.38 (m, 4H), 7.32-7.30 (m, 1H), 7.19 (d, J = 8.1 Hz, 2H),
7.06 (d, J = 8.3 Hz, 2H), 4.13 (s, 0.1H), 3.92 (s, 1.9H); 13C NMR
(101 MHz, CDCl3) δ 140.9, 140.1, 139.6, 139.4, 131.7, 130.8,
129.4, 128.8, 127.4, 127.3, 127.1, 120.1, 41.0. The carbons of the
minor product did not show on the 13C NMR spectra due to the
low concentration and limited scanning times.
CDCl3) δ 132.5, 132.1, 130.4, 123.7, 70.4, 38.4.
1
3-Iodobenzyl methanesulfonate (4f). Following the general
procedure, 4f was obtained as a white solid (2.63 g, 84%). H
NMR (400 MHz, CDCl3) δ 7.76-7.72 (m, 2H), 7 .38 (d, J = 7.6
Hz, 1H), 7.15 (t, J = 7.8 Hz, 1H), 5.16 (s, 2H), 2.97 (s, 3H); 13C
NMR (101 MHz, CDCl3) δ 138.4, 137.5, 135.7, 130.6, 127.8,
94.4, 70.0, 38.3.
1
1-Bromo-4-cinnamylbenzene (3l).25 Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
[1,1'-Biphenyl]-4-ylmethyl methanesulfonate (4g). Following the
general procedure, 4g was obtained as a white solid (2.03 g,
1
77%). H NMR (400 MHz, CDCl3) δ 7.64-7.57 (m, 4H), 7.50-
7.43 (m, 4H), 7.38-7.35 (m, 1H), 5.28 (s, 2H), 2.94 (s, 3H); 13C
NMR (101 MHz, CDCl3) δ 142.4, 140.2, 132.3, 129.4, 128.9,
127.8, 127.6, 127.2, 71.3, 38.4.
1
afford 3l as a colourless oil (26 mg, 19%). H NMR (400 MHz,
CDCl3) δ 7.42 (d, J = 8.3 Hz, 2H), 7.35-7.33 (m, 2H), 7.31-7.27
(m, 2H), 7.22-7.19 (m, 1H), 7.11 (d, J = 8.2 Hz, 2H), 6.43 (d, J =
15.8 Hz, 1H), 6.30 (dt, J = 15.7, 6.7 Hz, 1H) , 3.49 (d, J = 6.7 Hz,
2H); 13C NMR (101 MHz, CDCl3) δ 139.1, 137.3, 131.6, 130.4,
128.6, 128.4, 127.3, 126.2, 120.0, 38.7.
3-Nitrobenzyl methanesulfonate (4i). Following the general
1
procedure, 4i was obtained as a white solid (1.87 g, 81%). H
NMR (400 MHz, CDCl3) δ 8.28-8.24 (m, 2H), 7 .78 (d, J = 7.7
Hz, 1H), 7.62 (t, J = 7.9 Hz, 1H), 5.34 (s, 2H), 3.09 (s, 3H); 13C
NMR (101 MHz, CDCl3) δ 148.4, 135.8, 134.3, 130.1, 124.1,
123.2, 69.2, 38.2.
General Procedure for the Preparation of Benzyl Mesylates
To a flask that was charged with the benzyl alcohol (10 mmol),
o
triethylamine (20 mmol) in THF (25 mL) cooled at 0 C, was
added mesyl chloride (20 mmol) in THF (50 mL) over half an
hour. Then the mixture was allowed to stir at room temperature
for about 20-30 min. Cold water was added to the mixture, then
the mixture was extracted with diethyl ether (125 mL x 1).
Triethylamine (5 mol) was added into the crude product solution
to remove the unreacted mesyl chloride. Then the solution was
washed with saturated aqueous NaHCO3 (10 mL), cold water (25
mL) and brine (25 mL). The solution was dried over anhydrous
Na2SO4. Removal of the solvent under reduced pressure gave the
benzyl mesylate products, which are used in the coupling
reaction without further purification.
Methyl 4-(((methylsulfonyl)oxy)methyl)benzoate (4j). Following
the general procedure, 4j was obtained as a white solid (1.93 g,
79%). H NMR (400 MHz, CDCl3) δ 8.08 (d, J = 8.3 Hz, 2H), 7
.49 (d, J = 8.3 Hz, 2H), 5.29 (s, 2H), 3.93 (s, 3H), 2.98 (s, 3H);
13C NMR (101 MHz, CDCl3) δ 166.4, 138.3, 131.0, 130.1, 70.2,
52.3, 38.3.
1
3-Phenylprop-2-yn-1-yl methanesulfonate (4l). Following the
general procedure, 4l was obtained as a pale yellow oil (1.69 g,
1
80%). H NMR (400 MHz, CDCl3) δ 7.47-7.45 (m, 2H), 7.39-
7.32 (m, 3H), 5.09 (s, 2H), 3.16 (s, 3H); 13C NMR (101 MHz,
Benzyl methanesulfonate (4a). Following the general procedure,
CDCl3) δ 131.9, 129.5, 128.5, 121.2, 89.4, 80.8, 58.4, 39.1.
1
4a was obtained as a colourless oil (1.39 g, 75%). H NMR (400
MHz, CDCl3) δ 7.43-7.39 (m, 5H), 5.24 (s, 2H), 2.90 (s, 3H); 13C
NMR (101 MHz, CDCl3) δ 133.4, 129.4, 128.9, 128.9, 71.6,
38.4.
Phenethyl methanesulfonate (4m). Following the general
procedure, 4m was obtained as a pale yellow oil (1.52 g, 76%).
1H NMR (400 MHz, CDCl3) δ 7.35-7.31 (m, 2H), 7.28-7.23 (m,
3H), 4.42 (t, J = 6.9 Hz, 2H), 3.05 (t, J = 6.9 Hz, 2H), 2.83 (s,
3H); 13C NMR (101 MHz, CDCl3) δ 136.4, 129.0, 128.7, 127.1,
70.3, 37.3, 35.7.
2-Methylbenzyl methanesulfonate (4b). Following the general
procedure, 4b was obtained as a pale yellow oil (1.54 g, 77%). 1H
NMR (400 MHz, CDCl3) δ 7.36-7.28 (m, 2H), 7 .23-7.17(m,
2H), 5.25 (s, 2H), 2.86 (s, 3H), 2.40 (s, 3H); 13C NMR (101
MHz, CDCl3) δ 137.8, 131.4, 130.8, 130.3, 129.9, 126.3, 70.2,
38.2, 18.8.
General Procedure for the Preparation of Benzyl phosphates
Benzyl alcohol (10 mmol), DMAP (1 mmol) and triethylamine
(11 mmol) were dissolved in THF (100 mL). The diethyl
chlorophosphate (11 mmol) was added via syringe over 30 min.
The mixture was allowed to react at room temperature overnight.
Then the mixture was quenched with saturated aqueousNH4Cl,
extracted with diethyl ether (75 mL x 3). The combined organic
phase was dried over anhydrous Na2SO4 and then concentrated to
give the crude product, which was purified by column
chromatography (eluted with petroleum ether:ethyl acetate = 5:1
to 2:1).
2-Bromobenzyl methanesulfonate (4c). Following the general
procedure, 4c was obtained as a pale yellow oil (2.09 g, 79%). 1H
NMR (400 MHz, CDCl3) δ 7.61 (dd, J = 8.0, 0.8 Hz, 1H), 7.50
(dd, J = 7.6, 1.4 Hz, 1H), 7.37 (td, J = 7.5, 0.9 Hz, 1H), 7.26 (td,
J = 7.8, 1.6 Hz, 1H), 5.32 (s, 2H), 3.02 (s, 3H); 13C NMR (101
MHz, CDCl3) δ 133.1, 132.9, 130.9, 130.8, 127.9, 123.8, 70.9,
38.0.
2-Chlorobenzyl methanesulfonate (4d). Following the general
procedure, 4d was obtained as a pale yellow oil (1.85 g, 84%). 1H
NMR (400 MHz, CDCl3) δ 7.51-7.49 (m, 1H), 7.44-7.42 (m,
1H), 7.37-7.30 (m, 2H), 5.34 (s, 2H), 3.02 (s, 3H); 13C NMR (101
MHz, CDCl3) δ 134.1, 131.3, 130.8, 130.8, 129.8, 127.3, 68.7,
38.0.
4-Methoxybenzyl phosphate (4h). Following the general
procedure, 4h was obtained as a colourless oil (1.88 g, 69%). 1H
NMR (400 MHz, CDCl3) δ 7.33 (d, J = 8.7 Hz, 2H), 6.89 (d, J =
8.7 Hz, 2H), 5.00 (d, J = 8.4 Hz, 2H), 4.09-4.04 (m, 4H), 3.81 (s,
3H), 1.18 (t, J = 7.0 Hz, 6H, overlapped); 13C NMR (101 MHz,
CDCl3) δ 159.8, 129.8, 128.2 (JCP = 6.5 Hz), 113.9, 68.9 (JCP
5.5 Hz), 63.7 (JCP = 5.8 Hz), 55.3, 16.1 (JCP = 6.9 Hz).
=
4-Bromobenzyl methanesulfonate (4e). Following the general
procedure, 4e was obtained as a pale yellow oil (1.96 g, 74%). 1H
NMR (400 MHz, CDCl3) δ 7.55 (d, J = 8.4 Hz, 2H), 7.30 (d, J =
Cinnamyl diethyl phosphate (4k). Following the general
procedure, 4k was obtained as a colourless oil (1.70 g, 65%). 1H

ACCEPTED MANUSCRIPT
7
NMR (400 MHz, CDCl3) δ 7.41-7.38 (m, 2H), 7.35-7.31 (m,
2H), 7.28-7.25 (m, 1H), 6.68 (d, J = 15.9 Hz, 1H), 6.31 (dt, J =
15.8, 6.2 Hz, 1H), 4.72-4.68 (m, 2H), 4.17-4.10 (m, 4H), 1.34 (t,
J = 7.1 Hz, 6H, overlapped); 13C NMR (101 MHz, CDCl3) δ
136.1, 133.9, 128.6, 128.2, 126.7, 123.6 (JCP = 6.8 Hz), 67.9 (JCP
= 5.6 Hz), 63.8 (JCP = 5.8 Hz), 16.1 (JCP = 6.7 Hz).
residue was purified by column chromatography on silica gel
(eluted with petroleum ether) to afford pure 5f as a colourless oil
(68 mg, 61%). H NMR (400 MHz, CDCl3) δ 7.30-7.16 (m,
1
7.3H), 7.12-7.10 (m, 1.4H), 6.97-6.96 (m, 0.3H), 3.97 (s, 0.5H),
3.94 (s, 1.4H), 1.29 (s, 9H); 13C NMR (101 MHz, CDCl3) δ 151.3
(minor), 148.9, 141.3, 140.7 (minor), 138.1, 129.0, 129.0
(minor), 128.6, 128.5, 128.2 (minor), 126.1 (minor), 126.0, 126.0
(minor), 125.4, 123.1 (minor), 42.3 (minor), 41.5, 34.7 (minor),
34.4, 31.5, The other carbons of the minor product did not show
on the 13C NMR spectra due to the low concentration and limited
scanning times.
Reaction of Benzyl Mesylates with Arylboronic Acids
Arylboronic acid (0.5 mmol), KF (1.0 mmol) were added to a
Schlenk tube. The tube was charged with nitrogen and then DCE
(2 mL) and benzyl esters (0.75 mmol) were added. The mixture
o
was stirred at 70 C for 10-24 h. After the mixture was cooled
down to room temperature, solvent was removed to give a crude
product, which was purified by column chromatography on silica
gel, eluted with petroleum ether or petroleum ether:ethyl acetate
= 30:1 to afford the product. In some cases, the reaction was
1-Benzyl-2-methylbenzene28 and 1-benzyl-3-methylbenzene28(9:1)
(5g). Following the general procedure, the crude residue was
purified by column chromatography on silica gel (eluted with
petroleum ether) to afford 5g as a colourless oil (76 mg, 83%). 1H
NMR (400 MHz, CDCl3) δ 7.27-7.23 (m, 2H), 7.19-7.09 (m,
6.7H), 7.00-6.97 (m, 0.3H), 3.97 (s, 1.8H), 3.93 (s, 0.2H), 2.30 (s,
0.3H), 2.23 (s, 2.7H); 13C NMR (101 MHz, CDCl3) δ 141.3
(minor), 141.1 (minor), 140.5, 139.0, 138.1 (minor), 136.7,
130.3, 130.0, 129.8 (minor), 129.0, 128.8, 128.5 (minor), 128.5,
128.4 (minor), 126.9 (minor), 126.5, 126.0, 126.0, 42.0 (minor),
39.5, 21.5 (minor), 19.7. The other carbons of the minor product
did not show on the 13C NMR spectra due to the low
concentration and limited scanning times.
o
carried out at 100 C with LiOtBu as the base, as indicated in
Scheme 4.
Diphenylmethane (5a).2h Following the general procedure, the
crude residue was purified by column chromatography on silica
gel (eluted with petroleum ether) to afford pure 5a as a colourless
1
oil (66 mg, 77%). H NMR (400 MHz, CDCl3) δ 7.31-7.27 (m,
4H), 7.21-7.19 (m, 6H), 3.99 (s, 2H); 13C NMR (101 MHz,
CDCl3) δ 141.2, 129.0, 128.5, 126.1, 42.0.
1-Benzyl-4-bromobenzene (5b).17 Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
afford 5b as a colourless oil (104 mg, 84%). 1H NMR (400 MHz,
CDCl3) δ 7.39-7.36 (m, 2H), 7.29-7.25 (m, 2H), 7.21-7.17 (m,
1H), 7.15-7.13 (m, 2H), 7.04-7.02 (m, 2H), 3.90 (s, 2H); 13C
NMR (101 MHz, CDCl3) δ 140.5, 140.2, 131.6, 130.7, 128.9,
128.6, 126.4, 120.0, 41.4.
1-Benzylnaphthalene25 and 2-benzylnaphthalene (C1:C2 = 2:1)
(5h). Following the general procedure, the crude residue was
purified by column chromatography on silica gel (eluted with
1
petroleum ether) to afford 5h as a white solid (67 mg, 60%). H
NMR (400 MHz, CDCl3) δ 7.98-7.96 (m, 0.7H), 7.84-7.81 (m,
0.7H), 7.77-7.72 (m, 1.6H), 7.60 (s, 0.3H), 7.43-7.37 (m, 2.7H),
7.25-7.17 (m, 6H), 4.42 (s, 1.4H), 4.11 (s, 0.6H); 13C NMR (101
MHz, CDCl3) δ 141.1 (minor), 140.7, 138.7 (minor), 136.7,
134.1, 133.7 (minor), 132.3, 132.2 (minor), 129.1 (minor), 128.8,
128.8 (minor), 128.6, 128.5, 128.2 (minor), 127.7 (minor), 127.7
(minor), 127.4, 127.2, 127.2 (minor), 126.3 (minor), 126.2 ,
126.1, 125.6, 125.4 (minor), 124.4, 42.2 (minor), 39.1.
1-Benzyl-4-chlorobenzene (5c).26 Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
1
afford 5c as a colourless oil (71 mg, 70%). H NMR (400 MHz,
CDCl3) δ 7.29-7.19 (m, 5H), 7.17-7.13 (m, 2H), 7.10-7.08 (m,
2H), 3.92 (s, 2H); 13C NMR (101 MHz, CDCl3) δ 140.6, 139.6,
132.0, 130.3, 128.9, 128.6, 126.3, 41.3.
2-Benzylfuran2e and 3-benzylfuran2e (5:1) (5i). Following the
general procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
1
afford 5i as a colourless oil (32 mg, 41%). H NMR (400 MHz,
1-Benzyl-4-methoxybenzene (5d).27 Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
CDCl3) δ 7.35 (s, 0.2H), 7.32-7.20 (m, 6H), 6.28 (dd, J = 3.0, 1.9
Hz, 0.8H), 6.24 (s, 0.2H), 6.00 (d, J = 3.1 Hz, 0.8H), 3.97 (s,
1.7H), 3.77 (s, 0.3H); 13C NMR (101 MHz, CDCl3) δ 154.6,
143.1 (minor), 141.5, 139.6 (minor), 138.2, 128.7, 128.6 (minor),
128.5, 128.4 (minor), 126.5, 126.2 (minor), 111.3 (minor), 110.2,
106.2, 34.5, 31.2 (minor). The other carbons of the minor product
did not show on the 13C NMR spectra due to the low
concentration and limited scanning times.
1
afford 5d as a colourless oil (96 mg, 97%). H NMR (400 MHz,
CDCl3) δ 7.29-7.24 (m, 2H), 7.20-7.16 (m, 3H), 7.10 (d, J = 8.6
Hz, 2H), 6.82 (d, J = 8.6 Hz, 2H), 3.92 (s, 2H), 3.77 (s, 3H); 13C
NMR (101 MHz, CDCl3) δ 158.0, 141.6, 133.3, 129.9, 128.8,
128.4, 126.0, 113.9, 55.3, 41.1.
Methyl 4-benzylbenzoate17 and methyl 3-benzylbenzoate (2.5:1)
(5e). Following the general procedure, the crude residue was
purified by column chromatography on silica gel (eluted with
petroleum ether:ethyl acetate = 30:1) to afford 5e as a colourless
oil (57 mg, 45%). 1H NMR (400 MHz, CDCl3) δ 7.95 (d, J = 8.2
Hz, 1.4H), 7.90-7.87 (m, 0.6H), 7.35-7.15 (m, 7H), 4.01 (s, 2H),
3.88 (s, 3H); 13C NMR (101 MHz, CDCl3) δ 167.2 (minor),
167.1, 146.5, 141.5 (minor), 140.5 (minor), 140.1, 133.6 (minor),
130.4 (minor), 130.1 (minor) 129.8, 129.0, 128.9 (minor), 128.6,
128.6 (minor), 128.6 (minor), 128.1, 127.5 (minor), 126.4, 126.3
(minor), 52.1 (minor), 52.0, 41.9, 41.7 (minor).
2-Benzylthiophene2e and 3-benzylthiophene2e (2:1) (5j). Following
the general procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
afford 5j as a pale yellow oil (45 mg, 52%); 1H NMR (400 MHz,
CDCl3) δ 7.31-7.18 (m, 5.3H), 7.13-7.12 (m, 0.7H), 6.92-6.89
(m, 1.3H), 6.79-6.78 (m, 0.7H), 4.15 (s, 1.3H), 3.97 (s, 0.7H); 13
C
NMR (101 MHz, CDCl3) δ 144.1, 141.5 (minor), 140.6 (minor),
140.4, 128.8 (minor), 128.6 (minor), 128.6, 128.5, 126.8, 126.5,
126.2 (minor), 125.6 (minor), 125.2, 124.0, 121.3 (minor), 36.6
(minor), 36.1.
1-Benzyl-2-methylbenzene (5k).17 Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
1-Benzyl-4-(tert-butyl)benzene28
benzene (2.5:1) (5f). Following the general procedure, the crude
and
1-benzyl-3-(tert-butyl)

ACCEPTED MANUSCRIPT
8
Tetrahedron
afford 5k as a colourless oil (73 mg, 80%); 1H NMR (400 MHz,
CDCl3) δ 7.25-7.23 (m, 1H), 7.03-6.99 (m, 5H), 6.72 (d, J = 8.6
Hz, 2H), 3.93 (s, 2H), 3.65 (s, 3H); 13C NMR (101 MHz, CDCl3)
δ 158.2, 139.2, 134.2, 131.6, 130.9, 130.0, 129.6, 127.6, 126.9,
114.0, 55.3, 38.4
CDCl3) δ 7.28-7.24 (m, 2H), 7.20-7.09 (m, 7H), 3.98 (s, 2H),
2.24 (s, 3H); 13C NMR (101 MHz, CDCl3) δ 13C NMR (101
MHz, CDCl3) δ 140.4, 138.9, 136.6, 130.3, 130.0, 128.8, 128.4,
126.5, 126.0, 125.9, 39.5, 19.7.
1-Chloro-2-(2-methylbenzyl)benzene
and
1-chloro-2-(3-
1-(4-Methoxybenzyl)-2-methylbenzene (5l).29 Following the
general procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
afford 5l as a colourless oil (103 mg, 97%). 1H NMR (400 MHz,
CDCl3) δ 7.13-7.06 (m, 4H), 7.02 (d, J = 8.5 Hz, 2H), 6.80 (d, J =
8.5 Hz, 2H), 3.90 (s, 2H), 3.75 (s, 3H), 2.22 (s, 3H); 13C NMR
(101 MHz, CDCl3) δ 157.9, 139.4, 136.6, 132.5, 130.3, 129.9,
129.7, 126.4, 126.1, 113.9, 55.3, 38.6, 19.7.
methylbenzyl)benzene31 (9:1) (5r). Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
1
afford 5r as a colourless oil (84 mg, 77%). H NMR (400 MHz,
CDCl3) δ 7.40-7.38 (m, 1H), 7.25-7.13 (m, 5H), 7.00-6.98 (m,
1.2H), 6.90-6.88 (m, 0.9H), 4.06 (s, 2H), 2.31 (s, 0.3H), 2.24 (s,
2.7H); 13C NMR (101 MHz, CDCl3) δ 138.0, 137.5, 136.8, 134.3,
131.0 (minor), 130.3, 129.7 (minor), 129.7, 129.5 (minor), 129.3,
128.4 (minor), 127.5, 127.0 (minor), 126.8, 126.6, 126.1, 126.0
(minor), 36.7, 19.5. The other carbons of the minor product did
not show on the 13C NMR spectra due to the low concentration
and limited scanning times.
1-Bromo-2-(4-methoxybenzyl)benzene (5m). Following the
general procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
afford 5m as a colourless oil (115 mg, 83%). IR (film) 2828,
1609, 1511, 1246, 1026, 743 cm-1; 1H NMR (400 MHz, CDCl3) δ
7.55 (d, J = 8.0 Hz 1H), 7.23-7.19 (m, 1H), 7.11-7.06 (m, 4H),
6.83 (d, J = 8.6 Hz, 2H), 4.04 (s, 2H), 3.77 (s, 3H); 13C NMR
(101 MHz, CDCl3) δ 158.1, 140.8, 132.9, 131.6, 131.0, 130.0,
127.8, 127.5, 124.8, 113.9, 55.3, 40.9.
1-Bromo-4-(4-methoxybenzyl)benzene (5s).30 Following the
general procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
1
afford 5s as a white solid (127 mg, 92%). H NMR (400 MHz,
CDCl3) δ 7.38 (d, J = 8.4 Hz, 2H), 7.07-7.02 (m, 4H), 6.82 (d, J =
8.6 Hz, 2H), 3.86 (s, 2H), 3.77 (s, 3H); 13C NMR (101 MHz,
CDCl3) δ 158.2, 140.6, 132.6, 131.5, 130.6, 129.8, 119.8, 114.0,
55.3, 40.4.
2-(2-Bromobenzyl)furan and 3-(2-bromobenzyl)furan (9:1) (5n).
Following the general procedure, the crude residue was purified
by column chromatography on silica gel (eluted with petroleum
1
ether) to afford 5n as a colourless oil (45 mg, 38%); H NMR
1-Benzyl-3-iodobenzene (5t). Following the general procedure,
the crude residue was purified by column chromatography on
silica gel (eluted with petroleum ether) to afford 5t as a
colourless liquid (109 mg, 74%); IR (film) 1562, 1494, 1063, 768,
700, 657 cm-1; 1H NMR (400 MHz, CDCl3) δ 7.55-7.52 (m, 2H),
7.31-7.27 (m, 2H), 7.24-7.21 (m, 1H), 7.19-7.13 (m, 3H), 7.02-
6.98 (m, 1H), 3.91 (s, 2H); 13C NMR (101 MHz, CDCl3) δ 143.6,
140.2, 137.9, 135.2, 130.2, 128.9, 128.6, 128.2, 126.4, 94.6, 41.5;
EI-MS (m/z, relative intensity) 294 (M+, 98), 167 (100), 165 (96),
152 (43), 83 (31), 63 (14), 28 (21).
(400 MHz, CDCl3) δ 7.56 (d, J = 7.5 Hz, 1H), 7.26-7.21 (m, 3H),
7.12-7.09 (m, 4H), 4.08 (s, 0.2H), 4.07 (s, 1.8H); 13C NMR (101
MHz, CDCl3) δ 139.8, 138.0, 133.0, 132.1, 131.1 (minor), 131.0,
130.3, 129.7 (minor), 129.0 (minor), 128.6, 128.2 (minor), 128.2,
127.6 (minor), 127.6, 127.2 (minor), 126.5 (minor), 124.9, 41.4
(minor), 41.1. The other carbons of the minor product did not
show on the 13C NMR spectra due to the low concentration and
limited scanning times. EI-MS (m/z, relative intensity) 282 (M+,
37), 280 (28), 247 (23), 245 (22), 201 (39), 166 (80), 165 (100),
82 (40).
1-Iodo-3-(4-methoxybenzyl)benzene (5u). Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
afford 5u as a white solid (134 mg, 83%). m.p. 38-40 ºC; IR
1-Bromo-2-(4-chlorobenzyl)benzene
and
1-bromo-2-(3-
chlorobenzyl)benzene (9:1) (5o). Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
1
(film) 2831, 1509, 1246, 1177, 1035, 807, 783, 688 cm-1; H
1
afford 5o as a pale yellow oil (108 mg, 77%). H NMR (400
NMR (400 MHz, CDCl3) δ 7.53-7.51 (m, 2H), 7.12 (d, J = 7.7
Hz, 1H), 7.07 (d, J = 8.6 Hz, 2H), 7.00 (t, J = 7.7 Hz, 1H), 6.83
(d, J = 8.6 Hz, 2H), 3.85 (s, 2H), 3.78 (s, 3H); 13C NMR (101
MHz, CDCl3) δ 158.2, 144.1, 137.8, 135.1, 132.3, 130.2, 129.9,
128.1, 114.0, 94.6, 55.3, 40.6; EI-MS (m/z, relative intensity) 324
(M+, 100), 197 (45), 166 (39), 153 (43), 121 (58), 91 (23), 76
(17).
MHz, CDCl3) δ 7.55 (d, J = 8.0 Hz, 1H), 7.36-7.34 (m, 1H),
7.24-7.17 (m, 2H), 7.09 (dt, J = 7.8, 1.8 Hz, 1H), 6.30 (dd, J =
2.9, 2.0 Hz, 0.9H), 6.28 (s, 0.1H), 6.03 (d, J = 2.7 Hz, 1H), 4.10
(s, 1.8H), 3.89 (s, 0.2H); 13C NMR (101 MHz, CDCl3) δ 159.2,
141.6, 137.7, 132.8, 130.7, 128.2, 127.5, 124.5, 110.4, 107.0,
34.7. The other carbons of the minor product did not show on the
13C NMR spectra due to the low concentration and limited
scanning times.
1-(4-Bromobenzyl)-3-iodobenzene
and
1-bromo-3-(3-
iodobenzyl)benzene (6:1) (5v). Following the general procedure,
the crude residue was purified by column chromatography on
silica gel (eluted with petroleum ether) to afford 5v as a colorless
1-Benzyl-2-chlorobenzene (5p).17 Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
1
liquid (155 mg, 83%). H NMR (400 MHz, CDCl3) δ 7.55-7.51
1
afford 5p as a colourless oil (84 mg, 84%). H NMR (400 MHz,
(m, 2H), 7.40 (d, J = 8.3 Hz, 1.7H), 7.35-7.31 (m, 0.3H), 7.15-
7.07 (m, 1.3H), 7.04-6.99 (m, 2.7H), 3.87 (s, 0.3H), 3.85 (s,
1.7H); 13C NMR (101 MHz, CDCl3) δ 142.9, 142.6 (minor),
142.5 (minor), 139.2, 137.8 (minor), 137.8, 135.6 (minor), 135.5,
131.9 (minor), 131.7, 130.6, 130.3 (minor), 130.3, 130.2 (minor),
129.6 (minor), 128,2 (minor), 128.2, 127.6 (minor), 122.7
(minor), 120.3, 94.7, 41.0 (minor), 40.8.
CDCl3) δ 7.37-7.35 (m, 1H), 7.30-7.27 (m, 2H), 7.22-7.12 (m,
6H), 4.10 (s, 2H); 13C NMR (101 MHz, CDCl3) δ 139.5, 138.7,
134.3, 131.0, 129.6, 129.0, 128.5, 127.7, 126.8, 126.3, 39.2.
1-Chloro-2-(4-methoxybenzyl)benzene (5q)30 Following the
general procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
afford 5q as a colourless oil (106 mg, 91%). 1H NMR (400 MHz,

ACCEPTED MANUSCRIPT
9
1
4-(4-Methoxybenzyl)-1,1'-biphenyl (5w). Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether : ethyl
acetate = 30:1 ) to afford 5i as a white solid (127 mg, 93%). m.p.
afford 6c as a colourless oil (106 mg, 95%). H NMR (400
MHz, CDCl3) δ 7.36-7.34 (m, 2H), 7.30-7.26 (m, 2H), 7.21-7.14
(m, 3H), 6.86-6.84 (m, 2H), 6.43 (d, J = 15.8 Hz, 1H), 6.33(dt, J
= 15.7, 6.5 Hz, 1H), 3.79 (s, 3H), 3.49 (d, J = 6.5 Hz, 2H); 13C
NMR (101 MHz, CDCl3) δ 158.1, 137.6, 132.2, 130.8, 129.7,
129.6, 128.5, 127.1, 126.2, 114.0, 55.3, 38.5.
1
83-86 ºC; IR (film) 1510, 1247, 1036, 750, 696, 652 cm-1; H
NMR (400 MHz, CDCl3) δ 7.56 (d, J = 7.6 Hz, 2H), 7.52-7.50
(m, 2H), 7.41 (t, J = 7.6 Hz, 2H), 7.33-7.30 (m, 1H), 7.25-7.23
(m, 2H), 7.14 (d, J = 8.6 Hz, 2H), 6.85 (d, J = 8.6 Hz, 2H), 3.96
(s, 2H), 3.79 (s, 3H); 13C NMR (101 MHz, CDCl3) δ 158.1,
141.1, 140.7, 139.0, 133.1, 129.9, 129.2, 128.7, 127.2, 127.1,
127.0, 114.0, 55.3, 40.7; EI-MS (m/z, relative intensity) 274 (M+,
100), 272 (31), 243 (23), 197 (13), 165 (35), 121 (23), 77(11).
1-Methyl-4-(3-phenylprop-2-yn-1-yl)benzene and 1-methyl-3-(3-
phenylprop-2-yn-1-yl)benzene (3:1) (6d). Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
1
afford 6d as a colourless oil (96 mg, 93%). H NMR (400 MHz,
CDCl3) δ 7.45-7.42 (m, 2H), 7.31-7.27 (m, 4.5H), 7.32-7.31 (m,
0.8H), 7.14 (d, J = 7.9 Hz, 1.5H), 7.06-7.05 (m, 0.2H), 3.79 (s,
0.5H), 3.78 (s, 1.5H), 2.35 (s, 0.7H), 2.33 (s, 2.3H); 13C NMR
(101 MHz, CDCl3) δ 138.2 (minor), 136.7 (minor), 136.2, 133.7,
131.7, 129.2, 128.8 (minor), 128.5 (minor), 128.2, 127.9, 127.8,
127.4 (minor), 125.0 (minor), 123.8, 87.9, 87.7 (minor), 82.5
(minor), 82.5, 25.7 (minor), 25.4, 21.4 (minor), 21.1. The other
carbons of the minor product did not show on the 13C NMR
spectra due to the low concentration and limited scanning times.
Bis(4-methoxyphenyl)methane (5x).30 Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether:ethyl
1
acetate = 30 : 1) to afford 5x as a white solid (104 mg, 91%): H
NMR (400 MHz, CDCl3) δ 7.08 (d, J = 8.6 Hz, 4H), 6.82 (d, J =
8.6 Hz, 4H), 3,86 (s, 2H), 3.76 (s, 6H); 13C NMR (101 MHz,
CDCl3) δ 157.9, 133.7, 129.7, 113.9, 55.3, 40.1.
1-(tert-Butyl)-4-(4-methoxybenzyl)benzene and 1-(tert-butyl)-3-
(4-methoxybenzyl) benzene (9:1) (5y). Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
1,2-Diphenylethane (6e).32 Following the general procedure, the
crude residue was purified by column chromatography on silica
gel (eluted with petroleum ether) to afford 6e as a white solid (30
1
1
afford pure 5y as a colorless oil (58 mg, 46%); H NMR (400
mg, 33%). H NMR (400 MHz, CDCl3) δ 7.22-7.18 (m, 4H),
MHz, CDCl3) δ 7.29 (d, J = 8.2 Hz, 2H), 7.12-7.09 (m, 4H),
6.84-6.81 (m, 2H), 3,92 (s, 0.2H), 3.89 (s, 1.8H), 3.77 (s, 3H),
1.29 (s, 9H); 13C NMR (101 MHz, CDCl3) δ 157.9, 148.8, 138.6,
133.4, 129.9, 129.8 (minor), 128.4, 128.1 (minor), 125.9 (minor),
125.3, 113.9, 55.3, 41.3 (minor), 40.5, 34.4, 31.4, the other
carbons of the minor product shown no signal due to the low
concentration and limited scanning times; EI-MS (m/z, relative
intensity) 254 (M+, 42), 239 (100), 197 (21), 121 (46).
7.15-7.09 (m, 6H), 2.86 (s, 4H); 13C NMR (101 MHz, CDCl3) δ
141.8, 128.5, 128.3, 125.9, 37.9.
Acknowledgments
This project was supported by 973 program 2015CB856600) and
NSFC (Grant 21472004 and 21332002).
References and notes
1-(4-Methoxybenzyl)-3-nitrobenzene (5z).2e Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether:ethyl
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1
acetate = 10:1) to afford 5z as a white solid (97 mg, 80%): H
NMR (400 MHz, CDCl3) δ 8.06-8.04 (m, 2H), 7.51-7.44 (m,
2H), 7.10 (d, J = 8.5 Hz, 2H), 6.86 (d, J = 8.6 Hz, 2H), 4.02 (s,
2H), 3.79 (s, 3H), 2.23 (s, 2.70H); 13C NMR (101 MHz, CDCl3) δ
158.4, 143.7, 135.0, 131.4, 129.9, 129.3, 123.6, 121.3, 114.2,
55.3, 40.6
1-Benzyl-3-nitrobenzene (6a).2e Following the general procedure,
the crude residue was purified by column chromatography on
silica gel (eluted with petroleum ether: ethyl acetate = 10:1) to
1
afford 6a as a white solid (51 mg, 48%). H NMR (400 MHz,
CDCl3) δ 8.07-7.05 (m, 2H), 7.51 (d, J = 7.6 Hz, 1H), 7.46-7.42
(m, 1H), 7.32 (t, J = 7.4 Hz, 2H), 7.26-7.24 (m, 1H), 7.18 (d, J =
7.3 Hz, 2H), 4.08 (s, 2H); 13C NMR (101 MHz, CDCl3) δ 148.5,
143.2, 139.4, 135.1, 129.4, 128.9, 128.8, 126.8, 123.7, 121.4,
41.5.
Methyl 4-benzylbenzoate (6b).2e Following the general procedure,
the crude residue was purified by column chromatography on
silica gel (eluted with petroleum ether) to afford pure 6b as a
1
colourless liquid (64 mg, 57%); H NMR (400 MHz, CDCl3) δ
7.96-7.94 (m, 2H), 7.31-7.21 (m, 5H), 7.18-7.16 (m, 2H), 4.02 (s,
2H), 3.89 (s, 3H); 13C NMR (101 MHz, CDCl3) δ 167.1, 146.5,
140.1, 129.8, 129.0, 128.6, 128.1, 126.4, 52.0, 41.9.
1-Cinnamyl-4-methoxybenzene (6c).30 Following the general
procedure, the crude residue was purified by column
chromatography on silica gel (eluted with petroleum ether) to
6. Inamoto, K.; Hasegawa, C.; Hiroya, K.; Kondo, Y.; Osako, T.; Uozumi,

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Tetrahedron
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Supplementary data
Copies of 1H and/or 13C spectra for isolated products. This
material is available free of charge via the Internet at xxxxxxx.