Oxidative cross-coupling of allyl(trimethyl)silanes with aryl boronic acids by palladium catalysis

Article abstract of DOI:10.1016/j.tet.2018.10.055

The first oxidative cross-coupling of allylsilanes with aryl boronic acids has been developed by palladium catalysis. The reaction between β-substituted allyl(trimethyl)silanes and a wide range of aryl boronic acids afforded allylarenes in moderate to good yields and excellent selectivity. On the basis of experimental results and literature reports, it was suggested that the reaction might start from transmetalation of aryl boronic acid with AgOAc followed by transmetalation with Pd(II) to give an arylpalladium acetate complex as a key intermediate. This intermediate underwent either electrophilic addition/desilylation or transmetalation with allylsilane and subsequent reductive elimination to give the final product.

Full text of DOI:10.1016/j.tet.2018.10.055

Tetrahedron xxx (xxxx) xxx
Contents lists available at ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Oxidative cross-coupling of allyl(trimethyl)silanes with aryl boronic
acids by palladium catalysis
Zhibing Zhou, Zhen-Lin Hou, Fan Yang, Bo Yao*
MOE Key Laboratory of Cluster Science, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical
Engineering, Beijing Institute of Technology, Beijing 102488, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
The first oxidative cross-coupling of allylsilanes with aryl boronic acids has been developed by palladium
catalysis. The reaction between b-substituted allyl(trimethyl)silanes and a wide range of aryl boronic
Received 7 September 2018
Received in revised form
12 October 2018
Accepted 23 October 2018
Available online xxx
acids afforded allylarenes in moderate to good yields and excellent selectivity. On the basis of experi-
mental results and literature reports, it was suggested that the reaction might start from transmetalation
of aryl boronic acid with AgOAc followed by transmetalation with Pd(II) to give an arylpalladium acetate
complex as a key intermediate. This intermediate underwent either electrophilic addition/desilylation or
transmetalation with allylsilane and subsequent reductive elimination to give the final product.
© 2018 Elsevier Ltd. All rights reserved.
Keywords:
Oxidative cross-coupling
Palladium catalysis
Allyl(trimethyl)silane
Aryl boronic acid
1. Introduction
sensitive Lewis acids for the umpolung and poor chemoselectivity
in these reactions limited their application in organic synthesis.
As a type of mild nucleophilic allylation reagents, allylsilanes
display unique properties such as high stability, good solubility in
various solvents and controllable reactivity, therefore having broad
application in organic synthesis [1]. Being activated by electrophilic
addition to the allylic double bond [2] and/or nucleophilic attack at
the Si atom [3], allylsilanes can react with various electrophiles
including carbonyl compounds [4], alcohols [5], ethers [6], esters
[7], and others [8] to furnish diverse allylic compounds. However,
the reaction between allylsilanes and other types of nucleophiles
has been far less explored. A major strategy for these reactions was
the umpolung of allylsilanes by transforming them into highly
reactive allylic electrophiles such as allyltelluroxides [9], allylbis-
muthonium [10], hypervalent allyliodine(III) reagents [11], and
allylic cations [12] (Scheme 1a). Besides, the umpolung of other
nucleophiles by oxidizing them to free radicals [13] and cations
[14], was another strategy for the cross-coupling reaction (Scheme
1b). Many methods based on the above two strategies have been
developed for the synthesis of allylic ethers [12a,12b], amines [9],
Palladium is one of the most powerful transition-metals in
organic synthesis [15]. Palladium catalysts have not only been
widely used in traditional cross-coupling between an electrophile
and a nucleophile [16], but also in recent years been extensively
investigated in oxidative cross-coupling of two nucleophiles [17].
The palladium-catalyzed oxidative cross-coupling often uses a
Pd(II) catalyst, which mediates the cross-coupling of two nucleo-
philes, and an oxidant for re-oxidation of Pd(0) to Pd(II) (Scheme
2a). When the two nucleophiles are organometallic reagents, a
successful cross-coupling reaction often requires: (1) facile and
selective transmetalation of Pd(II) with two nucleophiles sequen-
tially, and (2) chemoselective oxidation of Pd(0) rather than the
nucleophiles by the oxidant. In this context, the first Pd-catalyzed
oxidative cross-coupling of arylsilanes with aryl boronic acids
was reported by Zhang and co-workers in 2015 (Scheme 2b) [18a],
although the oxidative cross-coupling of arylsilanes with arenes by
gold catalysis was disclosed by Lloyd-Jones and Russell in 2012
ꢀ
[18b]. Furthermore, Szabo and co-workers developed the intra-
azides [11], arenes [10,12c] and
[13,14]. However, the use of strong oxidants and/or moisture-
a
-allylated carbonyl compounds
molecular allylation of allyl(trimethyl)silane-tethered alcohols and
tosylamides in 2000 and 2001 (Scheme 2c) [19]. However, the
oxidative cross-coupling of allylsilanes with other nucleophiles
including organometallic reagents remains underdeveloped. In
connection with our interest in development of oxidative reaction
by palladium catalysis, we herein reported the first oxidative cross-
* Corresponding author.
E-mail address: yaobo@bit.edu.cn (B. Yao).
https://doi.org/10.1016/j.tet.2018.10.055
0040-4020/© 2018 Elsevier Ltd. All rights reserved.
Please cite this article as: Z. Zhou et al., Oxidative cross-coupling of allyl(trimethyl)silanes with aryl boronic acids by palladium catalysis,
Tetrahedron, https://doi.org/10.1016/j.tet.2018.10.055

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Z. Zhou et al. / Tetrahedron xxx (xxxx) xxx
Heck-type reaction with allylsilanes to give the Heck-coupling
product 4. In order to suppress the side-reactions and improve
the selectivity for the cross-coupling product 3, a detailed survey of
reaction parameters had been conducted.
2.2. Conditions optimization
At first, we chose trimethyl(2-phenylallyl)silane 1a and phenyl
boronic acid 2a as the test substrates. The reaction with 5 mol%
Pd(OAc)2 as the catalyst and 1.0 equiv Ag2CO3 as the oxidant in
toluene at 80 ꢀC under air atmosphere successfully furnished the
allyl-aryl coupling product 3aa in 20% yield (eq 1). Meanwhile, the
Heck-coupling product 4a and the homo-coupling product 5a were
also detected in 26% and 4.4% yield by GC. In order to reduce the
yield of 4a and increase the yield of 3aa, an extensive survey of
reaction parameters including bases, Pd catalysts, silver salts sol-
vents, and others led to several key observations (Tables S1eS5 in
ESI): (1) An extra base was not needed. The use of K2CO3 or Cs2CO3
led to the formation of biphenyl 5a as the major product with most
of the silane 1a unreacted. (2) Pd(II) salts such as Pd(OAc)2 and
PdCl2 were effective catalysts, while Pd(II) complexes with phos-
phine ligands showed very low catalytic activity. (3) Among various
silver salts, AgOAc was the optimal to yield 3aa in highest yield and
selectivity. Ag2CO3 promoted the formation of the Heck-coupling
product 4a, while Ag2O and AgO favored the homo-coupling of 2a
to give biphenyl 5a in high yield. (4) DMF was the optimal solvent
for the cross-coupling. Low ratio of 3aa/4a was found when toluene
was used as the solvent, and biphenyl 5a became the major product
when DMSO was applied. Further investigation of ligands, the
loading of 2a, temperatures and concentrations led to a set of
preliminary conditions, which involved the treatment of 1a
(0.1 mmol) and 2a (1.2 equiv) with 5 mol% Pd(OAc)2, 10 mol% 1,4-
benzoquinone (BQ) and 2.0 equiv AgOAc in DMF at 80 ꢀC under
air. Under these conditions, the reaction furnished 3aa in 68% yield,
the two side-products (4a and 5a) in 5% total yield and unreacted
1a in 19% yield (Table 1, entry 1).
Scheme 1. The umpolung strategies for the cross-coupling of allyl(trialkyl)silanes with
other nucleophiles.
coupling of allylsilanes with aryl boronic acids to give allylarenes
under palladium-catalyzed aerobic conditions (Scheme 2d).
2. Results and discussion
2.1. Reaction design
The challenges in palladium-catalyzed oxidative cross-coupling
between allylsilanes and aryl boronic acids include: (1) slow
transmetalation between allylsilanes and Pd(II) species, (2) alkene-
related side-reactions such as Heck reaction and Wacker oxidation,
(3) competitive homo-coupling of nucleophiles. To overcome these
problems, we developed a Pd(II)/Ag(I) catalytic system, under
which the facile generation of an electrophilic Ar-Pd-X complex
might be crucial for the success of the cross-coupling with high
efficiency and selectivity. Our reaction design is based on the
considerations below (Scheme 2d): Ag(I) salts can undergo facile
transmetalation with aryl boronic acid 2 to generate an Ar-Ag(I)
intermediate [20,21], which reacts with PdX2 to give an Ar-Pd(II)-
X intermediate; the electrophilic Ar-Pd(II)-X can react with allyl-
silane 1 by electrophilic addition/desilylation or direct trans-
metalation [22] to afford an allyl-Pd-Ar intermediate, from which
reductive elimination furnishes allylarene 3. Meanwhile, two side-
reactions via the Ar-Pd(II)-X intermediate can also take place: one is
the homo-coupling reaction of 2 to deliver biaryl 5; another is the
Scheme 2. Pd(II)-catalyzed oxidative cross-coupling of organosilanes with nucleophiles.
Please cite this article as: Z. Zhou et al., Oxidative cross-coupling of allyl(trimethyl)silanes with aryl boronic acids by palladium catalysis,
Tetrahedron, https://doi.org/10.1016/j.tet.2018.10.055

Z. Zhou et al. / Tetrahedron xxx (xxxx) xxx
3
Table 1
Further conditions optimization for the reaction of allyl(trimethyl)silane 1a with phenyl boronic acid 2a.a
Entry
Variation from the preliminary conditions
Yield (%)b
3aa
4
5
1a
1
2
3
4
5
6
7
8
e
68
63
35
55
58
46
25
56
4.6
24
57
77
81(72)
16
1.6
2.3
1.6
2.0
1.4
6.2
16
1.5
1.4
0
3.4
2.1
6.3
1.4
1.8
9.7
11
2.2
1.1
2.4
10
19
16
0.9
8.2
27
23
24
28
82
60
6.2
0.4
0.9
58
28
2.0 instead of 1.2 equiv 2a
no BQ, 2.0 instead of 1.2 equiv 2a
5 mol% instead of 10 mol% BQ
20 mol% instead of 10 mol% BQ
5.0 equiv H2O
4 Å MS (50 mg)
1.0 equiv HOAc
1.0 equiv KOAc
0.1 equiv 2,20-bipyridine
5.0 equiv DMSO
1.0 equiv DMSO
1.0 equiv DMSO, 5 mol% PdCl2 instead of Pd(OAc)2
1.0 equiv DMSO, no Pd catalyst
1.0 equiv DMSO, 5 mol% PdCl2 instead of Pd(OAc)2, 2.0 equiv Cu(OAc)2 instead of AgOAc
9
10
11
12c
13c
14c
15c
1.4
0.8
0.5
0
2.4
2.2
4.5
30
23
0.2
a
The preliminary conditions: 1a (0.1 mmol), 2a (0.12 mmol), Pd(OAc)2 (5 mol%), BQ (10 mol%), AgOAc (2.0 equiv), DMF (1 mL), 80 ꢀC, air, 12 h.
Yield was determined by GC analysis with 4-bromotoluene as the internal standard, isolated yield was provided in the parenthesis.
0.2 mmol 1a and 1 mL DMF. BQ ¼ Benzoquinone.
b
c
Next, further assessment of the reaction parameters of the
with b-aryl groups bearing either electron-withdrawing or
preliminary conditions was conducted. Firstly, in the absence of BQ,
the yield of 3aa was dramatically decreased to 35% (Table 1, entry
3). And 10 mol% BQ was found to give the best result (Table 1, entry
1e5). Additionally, methylated BQs such as 2-methyl-1,4-
benzoquinone and 2,3,5-trimethyl-1,4-benzoquinone were also
effective and yielded 3aa in slightly lower yields, while 2,3-
dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) was proven to be
not effective (Table S7 in ESI). These results suggested that BQ
might act as a ligand in Pd complexes. Secondly, in order to further
improve the conversion of 1a, additives including H2O, molecular
sieves (4 Å MS), HOAc, KOAc, 2,20-bipyridine and DMSO were
evaluated (Table 1, entries 6e12). Among these additives, DMSO
was found to be the most effective, and the reaction with 1.0 equiv
DMSO under otherwise the preliminary conditions delivered 3aa in
77% yield and a trace amount of unreacted 1a (Table 1, entry 12)
[23]. Thirdly, the use of PdCl2 instead of Pd(OAc)2 as the catalyst
further increased the yield of 3aa to 81% (Table 1, entry 13). Sur-
prisingly, the reaction without Pd catalyst still furnished 3aa in 16%
yield (Table 1, entry 14). The use of 2.0 equiv Cu(OAc)2 replacing
AgOAc led to 3aa in low yield and poor selectivity of cross-versus
homo-coupling (Table 1, entry 15). These results suggested that the
synergy between Pd(II) and Ag(I) salts might account for both of the
efficacy and high selectivity found in the oxidative cross-coupling
reaction. Finally, the optimal conditions were determined as: 1a
(0.2 mmol), 2a (1.2 equiv), PdCl2 (5 mol%), BQ (10 mol%), DMSO (1.0
equiv), AgOAc (2.0 equiv), DMF, 80 ꢀC, air.
electron-donating substituents reacted with phenyl boronic acid 2a
well and all these reactions furnished the corresponding products
(3ba to 3ia) in moderate to good yield (61e71%). Functional groups
such as alkyl (1b), halogen (1c-1f), alkoxyl (1g), cyano (1h) and
COOMe groups (1i) were well tolerated. In addition,
b-(2-
naphthyl)-substituted allyl(trimethyl)silane 1j reacted with 2a to
deliver the product 3ja in 66%.
Secondly, a wide range of aryl boronic acids having various
substituents at para- or meta-positions of the phenyl rings were
tested. All these aryl boronic acids were coupled with 1a smoothly
to afford the desired products in moderate to good yields (3ab-
3ao). The compatible functionalities included alkyl (2b-2c, 2n), aryl
(2d), halogen (2e-2g, 2m), CF3 (2h), cyano (2i, 2o), COOMe (2j),
formyl (2k), and methoxyl groups (2l). It is worth mentioning that
the side-products 4 and 5 were too little to be detected by NMR in
all the reactions of the scope study above. Interestingly, the con-
ditions were also applicable to heteroaryl boronic acids. Benzo-
furan-2-boronic acid 2p and 3-thiophene-boronic acid 2q reacted
with 1a respectively to furnish the products 3ap and 3aq, albeit in
low yield (25% for 3ap and 27% for 3aq) due to the facile degra-
dation of the formed cross-coupling products.
After testing the scope of allylsilanes and aryl boronic acids, we
continued to examine other organoboron reagents as the coupling
partners in the reaction with allyl(trimethyl)silanes (Scheme 4).
The use of phenylboroxine and various phenyl boronic esters in the
reaction with 1a under the optimal conditions above led to the
formation of 3aa in 26e61% yield and a trace amount of 4a and 5a
(Scheme 4a). However, the reaction of 1a with PhBF3K under the
same conditions only delivered a trace product. Interestingly,
methyl boronic acid was found to be a competent coupling partner,
which reacted with 1j to furnish the methylation product 6 in 51%
yield. But similar reaction of cyclohexyl boronic acid failed to yield
2.3. Substrate scope
With the optimal conditions for the reaction between 1a and 2a,
we continued to examine the substrate scope of allyl(trimethyl)
silanes and aryl boronic acids (Scheme 3). Firstly, silanes with
the desired product, probably due to the existence of
b-hydrogen
substituted allyl groups were tested. The study showed that
b-aryl
[24]. Furthermore, the pinacol methylboronate could also be
substitution was crucial to the cross-coupling reaction. Allylsilanes
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Z. Zhou et al. / Tetrahedron xxx (xxxx) xxx
Scheme 3. Substrate scope for the cross-coupling of allyl(trimethyl)silanes with aryl boronic acidsa.
coupled with 1j. The reaction not only gave the methylation
product 6, but also an acetoxylation product 7 (Scheme 4b). Un-
fortunately, when the pinacol allylboronate and benzylboronate
were used, only the acetoxylation product 7 was isolated in 26% and
34% yield.
2.4. Mechanism discussion
To gain more mechanistic insights, several control experiments
were conducted: (1) the reaction of 2-phenylpropene 8 with 2a
under the standard conditions was found to deliver a mixture of
3aa and its isomer 9, which was not detected in the reaction be-
tween 1a and 2a (eq 1, Scheme 5); (2) heating the Heck-coupling
product 4 under the standard conditions did not give 3aa (eq 2,
Scheme 5). The results of these experiments indicated that neither
8 nor 4 was the intermediate in the oxidative cross-coupling be-
tween 1a and 2a, and further ruled out both of the proto-
desilylation/coupling
pathway
and
the
Heck-coupling/
protodesilylation pathway as possible mechanisms.
As found in the part of conditions optimization, AgOAc could
also mediate the oxidative cross-coupling in the absence of palla-
dium catalysts to give the product 3aa, albeit in low yield. This
reaction was totally quenched by addition of 5.0 equiv TEMPO (eq 3,
Scheme 5), indicating that the silver-mediated reaction followed a
radical pathway. However, the reaction under the standard condi-
tions (with 5 mol% PdCl2) in the presence of 5.0 equiv TEMPO still
gave 3aa in 19% after 16 h. The results suggested that the Pd-
catalyzed oxidative reaction followed an ionic pathway.
On the basis of the results above and literature reports, a plau-
sible mechanism for the Pd(II)-catalyzed oxidative cross-coupling
of allylsilanes with aryl boronic acids was proposed as shown in
Scheme 4. Reaction of other organoboron reagents with allyl(trimethyl)silanes.
Please cite this article as: Z. Zhou et al., Oxidative cross-coupling of allyl(trimethyl)silanes with aryl boronic acids by palladium catalysis,
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Z. Zhou et al. / Tetrahedron xxx (xxxx) xxx
5
was proposed to undergo silver-mediated transmetalation to form
ArPd(BQ)nOAc, proceed through the interaction with allylsilanes to
give ArPd(BQ)n(allyl), and finally afford the final product 3 by
reductive elimination.
4. Experimental section
4.1. General information
Solvents, starting materials, catalysts were purchased from
Chemical companies and used without further purification. Chro-
matographic purification was conducted with technical grade sol-
vents (petroleum ether, dichloromethane and ethyl acetate) and
silica gel 40e63 mm. TLC was performed on silica gel 60 F254 TLC
glass plates and visualized with UV light (254 nm). 1H and 13C NMR
spectra were recorded on a 400 MHz spectrometer. Chemical shifts
were referenced relative to residual solvent signal (CDCl3: 7.26 ppm
for 1H NMR, 77.16 ppm for 13C NMR). Infrared spectra were recor-
ded on a Brucker Alpha-FTIR, which could be used to obtain FTIR
transmission spectra in the range of 500e4000 cmꢁ1 and were
reported as cmꢁ1 (w ¼ weak, m ¼ medium, s ¼ strong). HRMS were
performed on a mass spectrometer (APCI-MS). Melting points were
measured with micro melting point apparatus.
Scheme 5. Control experiments.
4.2. Preparation of allyl(trimethyl)silanes
Fig. 1. The reaction might start from transmetalation of aryl boronic
acid 2 with AgOAc to generate an aryl-Ag intermediate IA, which
further reacted with Pd(II) in the presence of BQ to deliver an
ArPd(BQ)nOAc complex IB [20,21]. IB could proceed through either
electrophilic addition/desilylation or direct transmetalation to form
an ArPd(BQ)n(allyl) complex IC [22,25]. Reductive elimination of IC
furnished the final product 3 and Pd0(BQ)n, which could be reoxi-
dized to Pd(OAc)2(BQ)n by AgOAc. Although another mechanism
involving silver-mediated radical addition of aryl radicals to allyl-
silanes was also possible, it was a minor process to produce 3.
4.2.1. (2-(4-Chlorophenyl)allyl)trimethylsilane (1d)
1d was prepared from 40-chloroacetophenone according to the
procedure reported in the literature [26]. Colorless oil. 1H NMR
(400 MHz, CDCl3)
d 7.35e7.28 (m, 2H), 7.28e7.21 (m, 2H), 5.10 (d,
J ¼ 1.4 Hz, 1H), 4.86 (d, J ¼ 0.9 Hz, 1H), 1.97 (s, 2H), ꢁ0.11 (s, 9H). 13
C
NMR (101 MHz, CDCl3)
d 145.6, 141.4, 133.1, 128.4, 127.8, 110.7,
26.2, ꢁ1.3. IR (neat) 698(w), 734(w), 767(w), 837(m), 855(s),
881(m), 942(w), 1013(m), 1094(m), 1160(w), 1251(m), 1491(m),
1615(w), 2955(w). HRMS (APCI) Calcd for C12H16ClSiꢁ [M ꢁ H]-
223.0715; Found 223.0717.
3. Conclusion
4.2.2. (2-(3-Chlorophenyl)allyl)trimethylsilane (1h)
1h was prepared from 30-chloroacetophenone according to the
In conclusion, we have developed an oxidative cross-coupling of
allyl(trimethyl)silanes with aryl boronic acids by Pd(II) catalysis.
This reaction delivered allylic arenes in moderate to good yields
and excellent selectivity from a wide range of aryl boronic acids and
same procedure for the synthesis of 1d. 76% yield. Colorless oil. 1H
NMR (400 MHz, CDCl3)
d 7.38 (s, 1H), 7.30e7.25 (m, 1H), 7.25e7.19
(m, 2H), 5.13 (d, J ¼ 1.3 Hz, 1H), 4.90 (d, J ¼ 0.8 Hz, 1H), 1.98 (s,
2H), ꢁ0.09 (s, 9H). 13C NMR (101 MHz, CDCl3)
d 145.6, 144.9, 134.2,
a series of
b
-aryl substituted allyl(trimethyl)silanes. The reaction
129.5, 127.3, 126.6, 124.6, 111.3, 26.2, ꢁ1.29. IR (neat) 700(w),
722(w), 788(m), 854(s), 881(m), 1084(w), 1157(w), 1250(m),
1290(w), 1562(w), 2956(w). HRMS (APCI) Calcd for C12H16ClSiꢁ
[M ꢁ H]- 223.0715; Found 223.0717.
4.2.3. (2-(3-Methoxyphenyl)allyl)trimethylsilane (1i)
1i was prepared from ethyl 3-methoxybenzoate according to the
procedure reported in the literature [27]. Colorless oil. 1H NMR
(400 MHz, CDCl3)
d
7.27e7.19 (m,1H), 7.01 (d, J ¼ 7.7 Hz,1H), 6.96 (s,
1H), 6.81 (d, J ¼ 8.1 Hz, 1H), 5.15 (s, 1H), 4.88 (s, 1H), 3.83 (s, 3H),
2.02 (s, 2H), ꢁ0.07 (s, 9H) ppm. 13C NMR (101 MHz, CDCl3)
d 159.5,
146.6, 144.5, 129.1, 119.1, 112.5, 112.5, 110.3, 55.3, 26.3, ꢁ1.3. IR (neat)
700 (w), 726 (w), 787 (w), 855 (s), 1050 (m), 1248 (m), 1300 (w),
1577(m), 1599(w), 2955(w) cmꢁ1
. HRMS (APCI) Calcd for
C
13H21OSiþ [MþH]þ 221.1356; Found 221.1365.
4.3. General procedure for conditions screening
To an oven-dried schlenck tube with a magnetic stirring bar was
added phenylboronic acid 2a, a Pd catalyst, a base, a silver salt and
additives. Then trimethyl(2-phenylallyl)silane 1a (19.04 mg,
0.1 mmol) in a solvent (1 mL) was added to the schlenck tube by a
Fig. 1. Plausible mechanism.
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syringe. After being heated and stirred under air atmosphere for
12e16 h, the reaction mixture was treated with a saturated NaHCO3
aqueous solution (5 mL) and the resulting mixture was extracted by
ethyl acetate (3 ꢂ 5 mL). Then the combined organic extracts were
washed with brine (3 ꢂ 5 mL), dried over Na2SO4 and filtered. To
the organic extracts was added 4-bromotoluene (8 mg) as the in-
ternal standard for gas chromatographic analysis to give GC yields.
1392 (m),1490 (s),1625 (w), 2918 (w), 3027 (w). HRMS (APCI) Calcd
for C16H14Brþ [MþH]þ 273.0273; Found 273.0266.
4.4.6. 1-Chloro-3-(3-phenylprop-1-en-2-yl)benzene (3fa)
31.80 mg, 69% yield. Colorless oil. 1H NMR (400 MHz, CDCl3)
d
7.41 (s, 1H), 7.32e7.23 (m, 3H), 7.23e7.12 (m, 5H), 5.48 (s, 1H), 5.06
(s, 1H), 3.80 (s, 2H). 13C NMR (101 MHz, CDCl3)
d
146.0, 142.8, 139.1,
134.3, 129.6, 129.0, 128.6, 127.6, 126.5, 126.4, 124.5, 115.9, 41.6. IR
(neat, cmꢁ1) 700 (s), 789 (m), 905 (m),1076 (w),1453 (m),1494 (m),
1562 (m), 1593 (m), 3027 (w). HRMS (APCI) Calcd for C16H14Clþ
[MþH]þ 229.0779; Found 229.0766.
4.4. General procedure for the scope study
A mixture of phenyl boronic acid 2a (26.26 mg, 0.24 mmol),
PdCl2
(1.77 mg,
0.01 mmol), 1,4-benzoquinone
(2.16 mg,
0.02 mmol), AgOAc (66.77 mg, 0.4 mmol), DMSO (14
m
L, 0.2 mmol),
4.4.7. 1-Methoxy-3-(3-phenylprop-1-en-2-yl)benzene (3ga)
trimethyl(2-phenylallyl)silane 1a (38.07 mg, 0.2 mmol) in DMF
(1.0 mL) was stirred at 80 ꢀC under air for 16 h. Then the reaction
mixture was treated with a saturated NaHCO3 aqueous solution
(10 mL) and the resulting mixture was extracted by ethyl acetate
(3 ꢂ 10 mL). Then the combined organic extracts were washed with
brine (20 mL), dried over Na2SO4 and filtered. After concentration,
the residue was submitted to 1H NMR analysis with CDCl3 as the
solvent. The crude sample was further purified by flash chroma-
tography on a silica gel column with petroleum ether as the eluent
to give the product 3aa as a colorless liquid.
28.70 mg, 64% yield. Colorless oil. 1H NMR (400 MHz, CDCl3)
d
7.40e7.08 (m, 6H), 7.03 (d, J ¼ 7.6 Hz, 1H), 6.96 (s, 1H), 6.78 (d,
J ¼ 8.1 Hz, 1H), 5.49 (s, 1H), 5.02 (s, 1H), 3.81 (s, 2H), 3.77 (s, 3H). 13
C
NMR (101 MHz, CDCl3)
d 159.6, 147.0, 142.5, 139.6, 129.3, 129.1,
128.5, 126.2, 118.9, 114.9, 112.9, 112.2, 55.3, 41.8. IR (neat, cmꢁ1) 705
(m), 785 (m), 901 (m), 1050 (m), 1237 (m), 1288 (m), 1492 (m), 1577
(s), 1600 (s), 2935 (w), 3027 (w). HRMS (APCI) Calcd for
C
16H17Oþ[MþH]þ 225.1274; Found 225.1272.
4.4.8. 4-(3-Phenylprop-1-en-2-yl)benzonitrile (3ha)
30.87 mg, 70% yield. White solid. mp. 79.0e81.0 ꢀC. 1H NMR
4.4.1. Prop-2-ene-1,2-diyldibenzene (3aa)
(400 MHz, CDCl3)
d
7.56 (d, J ¼ 7.8 Hz, 2H), 7.49 (d, J ¼ 7.8 Hz, 2H),
28.10 mg, 72% yield. Colorless oil. 1H NMR (400 MHz, CDCl3)
7.31e7.23 (m, 2H), 7.21e7.08 (m, 3H), 5.58 (s, 1H), 5.21 (s, 1H), 3.83
d
7.43 (d, J ¼ 7.3 Hz, 2H), 7.34e7.12 (m, 8H), 5.49 (s, 1H), 5.01 (s, 1H),
(s, 2H). 13C NMR (101 MHz, CDCl3)
d 145.6, 145.4, 138.6, 132.3, 128.9,
3.83 (s, 1H). 13C NMR (101 MHz, CDCl3)
d
147.1, 141.0, 139.7, 129.1,
128.7, 127.0, 126.6, 119.0, 117.7, 111.1, 41.5. IR (neat, cmꢁ1) 559 (m),
704 (s), 755 (s), 847 (s), 908 (m), 1083 (m), 1492 (m), 1601 (m), 2222
(m), 2910 (w). HRMS (APCI) Calcd for C16H14Nþ [MþH]þ 220.1121;
Found 220.1117.
128.5, 128.4, 127.6, 126.3, 126.2, 114.7, 41.8. The NMR data is in good
agreement with that reported in the literature [28].
4.4.2. 1-Methyl-4-(3-phenylprop-1-en-2-yl)benzene (3ba)
27.57 mg, 66% yield. Colorless oil. 1H NMR (400 MHz, CDCl3)
4.4.9. Methyl 4-(3-phenylprop-1-en-2-yl)benzoate (3ia)
d
7.33 (d, J ¼ 7.7 Hz, 2H), 7.29e7.14 (m, 5H), 7.09 (d, J ¼ 7.6 Hz, 2H),
35.87, 71% yield. White solid. mp. 60.1e62.5. 1H NMR (400 MHz,
5.46 (s, 1H), 4.97 (s, 1H), 3.82 (s, 2H), 2.31 (s, 3H). 13C NMR
CDCl3)
(m, 2H), 7.22e7.09 (m, 3H), 5.57 (s, 1H), 5.13 (s, 1H), 3.88 (s, 3H),
3.84 (s, 2H). 13C NMR (101 MHz, CDCl3)
167.0, 146.4, 145.4, 139.1,
d
7.94 (d, J ¼ 7.8 Hz, 2H), 7.47 (d, J ¼ 7.9 Hz, 2H), 7.30e7.22
(101 MHz, CDCl3)
d 146.8, 139.8, 138.0, 137.3, 129.09, 129.05, 128.5,
126.2, 126.1, 113.9, 41.8, 21.2. IR (neat, cmꢁ1) 701 (s), 736 (m), 828
(s), 896 (m), 1453 (m), 1513 (m), 1624 (w), 2920 (w), 3026 (w).
HRMS (APCI) Calcd for C16H1þ7 [MþH]þ 209.1325; Found 209.1322.
d
129.8, 129.2, 129.0, 128.6, 126.4, 126.3, 116.6, 52.2. 41.6. IR (neat,
cmꢁ1) 697 (s), 719 (m), 783 (m), 903 (m), 1110 (m), 1181 (m), 1278
(s), 1438 (m), 1603 (m), 1714 (s), 2916 (w). HRMS (APCI) Calcd for
4.4.3. 1-Fluoro-4-(3-phenylprop-1-en-2-yl)benzene (3ca)
C
17H17Oþ2 [MþH]þ 253.1223; Found 253.1218.
27.62 mg, 65% yield. Colorless oil. 1H NMR (400 MHz, CDCl3)
d
7.38 (m, 2H), 7.30e7.13 (m, 5H), 6.96 (t, J ¼ 8.3 Hz, 2H), 5.43 (s,1H),
4.4.10. 2-(3-Phenylprop-1-en-2-yl)naphthalene (3ja)
5.02 (s, 1H), 3.80 (s, 2H). 13C NMR (101 MHz, CDCl3)
d
162.4 (d,
32.24 mg, 66% yield. White solid. mp. 55.1e56.5 ꢀC. 1H NMR
J ¼ 246.3 Hz), 161.2, 146.0, 139.4, 136.9 (d, J ¼ 3.3 Hz), 129.0, 128.5,
127.9 (d, J ¼ 8.0 Hz) 126.3, 115.2 (d, J ¼ 21.3 Hz), 114.7, 42.0. IR (neat,
cmꢁ1) 478 (s), 701 (s), 748 (w), 825 (m), 899 (m), 1232 (m), 1453
(m), 1508 (m), 1624 (w), 3057 (w). HRMS (APCI) Calcd for C15H14Fþ
[MþH]þ 213.1074; Found 213.1072.
(400 MHz, CDCl3)
J ¼ 8.6 Hz, 1H), 7.50e7.38 (m, 2H), 7.32e7.08 (m, 5H), 5.64 (s, 1H),
5.13 (s, 1H), 3.96 (s, 2H). 13C NMR (101 MHz, CDCl3)
146.9, 139.7,
138.1, 133.5, 132.9, 129.1, 128.5, 128.4, 127.9, 127.6, 126.3, 126.2,
126.0, 125.1, 124.7, 115.3, 41.8. IR (neat, cmꢁ1) 701 (s), 749 (s), 825
(m), 864 (m), 899 (m)þ, 947 (w), 1494 (w), 1623 (w), 2900 (w). HRMS
(APCI) Calcd for C19H17 [MþH]þ 245.1325; Found 245.1322.
d 7.85 (s, 1H), 7.82e7.70 (m, 3H), 7.62 (d,
d
4.4.4. 1-Chloro-4-(3-phenylprop-1-en-2-yl)benzene (3da)
31.84 mg, 69% yield. Colorless oil. 1H NMR (400 MHz, CDCl3)
d
7.34 (d, J ¼ 7.6 Hz, 2H), 7.31e7.14 (m, 7H), 5.47 (s, 1H), 5.06 (s, 1H),
4.4.11. 1-Methyl-4-(2-phenylallyl)benzene (3ab)
3.80 (s, 2H). 13C NMR (101 MHz, CDCl3)
d
145.9, 139.3, 139.2, 133.4,
27.44 mg, 66% yield. Color oil. 1H NMR (400 MHz, CDCl3)
d 7.43
129.0128.6, 128.5, 127.6, 126.4, 115.3, 41.7. IR (neat, cmꢁ1) 700 (m),
739 (m), 837 (s), 903 (m), 1012 (m), 1099 (m), 1493 (s), 2920 (w).
HRMS (APCI) Calcd for
229.0772.
(d, J ¼ 7.3 Hz, 2H), 7.33e7.19 (m, 3H), 7.15e7.02 (m, 4H), 5.47 (s, 1H),
5.01 (s, 1H), 3.79 (s, 2H), 2.30 (s, 3H). 13C NMR (101 MHz, CDCl3)
C
16H14Clþ [MþH]þ 229.0779; Found
d 147.3, 141.0, 136.6, 135.7, 129.2, 128.9, 128.4, 127.5, 126.3, 114.5,
41.3, 21.2. The NMR data is in good agreement with that reported in
the literature [29].
4.4.5. 1-Bromo-4-(3-phenylprop-1-en-2-yl)benzene (3ea)
33.50 mg, 61% yield. White solid. mp. 36.5e38.5 ꢀC. 1H NMR
4.4.12. 1-(tert-Butyl)-4-(2-phenylallyl)benzene (3ac)
(400 MHz, CDCl3)
d
7.39 (d, J ¼ 7.7 Hz, 2H), 7.32e7.12 (m, 7H), 5.48
30.16 mg, 60% yield. White solid. mp. 39.0e40.2 ꢀC. 1H NMR
(s, 1H), 5.06 (s, 1H), 3.80 (s, 2H). 13C NMR (101 MHz, CDCl3)
d
146.0,
(400 MHz, CDCl3)
(d, J ¼ 7.8 Hz, 2H), 5.49 (s, 1H), 5.01 (s, 1H), 3.80 (s, 2H), 1.29 (s, 9H).
13C NMR (101 MHz, CDCl3)
149.0, 147.1, 141.1, 136.6, 128.7, 128.4,
d
7.45 (d, J ¼ 7.6 Hz, 2H), 7.34e7.20 (m, 5H), 7.15
139.8, 139.2, 131.5, 129.0, 128.6, 128.0, 126.4, 121.6, 115.3, 41.7. IR
(neat, cmꢁ1) 699 (m), 735 (s), 835 (s), 903 (m), 1008 (m), 1073 (m),
d
Please cite this article as: Z. Zhou et al., Oxidative cross-coupling of allyl(trimethyl)silanes with aryl boronic acids by palladium catalysis,
Tetrahedron, https://doi.org/10.1016/j.tet.2018.10.055

Z. Zhou et al. / Tetrahedron xxx (xxxx) xxx
7
127.6, 126.3, 125.4, 114.6, 41.1, 34.5, 31.5. IR (neat, cmꢁ1) 551 (s), 604
(m), 690 (m), 776 (s), 892 (m), 1267 (m), 1494 (m), 1514 (m), 1622
(m), 2962 (m). HRMS (APCI) Calcd for C19Hþ23 [MþH]þ 251.1794;
Found 251.1786.
NMR (101 MHz, CDCl3)
d
167.2, 146.3, 145.2, 140.5, 129.8, 129.1,
128.5, 128.3, 127.8, 126.2, 115.2, 52.1, 41.8. IR (neat, cmꢁ1) 696 (m),
736 (w), 761 (w), 780 (w), 911 (w), 1020 (w), 1110 (m), 1183 (w),
1281 (s), 1439 (w), 1610 (w), 1722 (s), 2925 (w). HRMS (APCI) Calcd
for C17H17Oþ2 [MþH]þ 253.1223; Found 253.1219.
4.4.13. 4-(2-Phenylallyl)-1,10-biphenyl (3ad)
27.03 mg, 50% yield. White solid. mp. 85.9e88.2 ꢀC. 1H NMR
4.4.20. 4-(2-Phenylallyl)benzaldehyde (3ak)
(400 MHz, CDCl3)
7.43e7.37 (m, 2H), 7.34e7.20 (m, 6H), 5.52 (s, 1H), 5.07 (s, 1H), 3.87
(s, 2H). 13C NMR (101 MHz, CDCl3)
146.9, 141.1, 140.9, 139.1, 138.8,
d
7.56 (d, J ¼ 7.6 Hz, 2H), 7.52e7.44 (m, 4H),
26.94 mg, 60% yield. Yellow oil. 1H NMR (400 MHz, CDCl3)
d
9.95
(s, 1H), 7.78 (d, J ¼ 7.6 Hz, 2H), 7.39 (br, 4H), 7.31e7.13 (m, 3H), 5.54
(s, 1H), 5.07 (s, 1H), 3.92 (s, 2H). 13C NMR (101 MHz, CDCl3)
192.1,
d
d
129.5, 128.8, 128.4, 127.7, 127.23, 127.19, 127.1, 126.3, 114.8, 41.4. IR
(neat, cmꢁ1) 711 (s), 750 (m), 777 (m), 822 (w), 861 (w), 890 (w),
1267 (m), 1668 (m). HRMS (APCI) Calcd for C21Hþ19 [MþH]þ
271.1481; Found 271.1477.
147.1, 146.1, 140.3, 134.9, 130.1, 129.7, 128.5, 127.9, 126.2, 115.5, 42.0.
IR (neat, cmꢁ1) 706 (m), 780 (m), 819 (m), 900 (m), 1168 (m), 1212
(m), 1605 (m), 1698 (s), 2925 (w). HRMS (APCI) Calcd for C16H15Oþ
[MþH]þ 223.1117; Found 223.1111.
4.4.14. 1-Fluoro-4-(2-phenylallyl)benzene (3ae)
4.4.21. 1-Methoxy-4-(2-phenylallyl)benzene (3al)
31.25mg, 73% yield. Colorless oil. 1H NMR (400 MHz, CDCl3)
25.56 mg, 57% yield. Colorless oil. 1H NMR (400 MHz, CDCl3)
d
7.40 (d, J ¼ 7.5 Hz, 2H), 7.32e7.22 (m, 3H), 7.20e7.13 (m, 2H), 6.94
d
7.45 (d, J ¼ 7.6 Hz, 2H), 7.34e7.23 (m, 3H), 7.16 (d, J ¼ 8.1 Hz, 2H),
(t, J ¼ 8.2 Hz, 2H), 5.48 (s, 1H), 5.01 (s, 1H), 3.80 (s, 2H). 13C NMR
6.84 (d, J ¼ 8.2 Hz, 2H), 5.49 (s, 1H), 5.03 (s, 1H), 4.06e3.42 (m, 5H).
(101 MHz, CDCl3)
d
161.6 (d, J ¼ 243.9 Hz), 147.1, 140.7, 135.2 (d,
13C NMR (101 MHz, CDCl3)
d 158.1, 147.5, 141.0, 131.7, 130.0, 128.4,
J ¼ 3.2 Hz), 130.4 (d, J ¼ 7.8 Hz), 128.4, 127.7, 126.3, 115.3 (d,
J ¼ 21.2 Hz), 114.8, 41.0. IR (neat, cmꢁ1) 704 (m), 782 (m), 823 (m),
902 (m), 1157 (w), 1222 (m), 1508 (s), 1601 (w). HRMS (APCI) Calcd
for C15H14Fþ [MþH]þ 213.1074; Found 213.1071.
127.5, 126.3, 114.4, 113.9, 55.3, 40.9. IR (neat, cmꢁ1) 704 (m), 780
(m), 819 (w), 900 (w), 1036 (m), 1177 (m), 1247 (s), 1511 (s), 1611
(w), 2834 (w). HRMS (APCI) Calcd for C16H17Oþ [MþH]þ 225.1274;
Found 225.1271.
4.4.15. 1-Chloro-4-(2-phenylallyl)benzene (3af)
4.4.22. 1-Fluoro-3-(2-phenylallyl)benzene (3am)
21.06 mg, 46% yield. White solid. mp. 41.5e43.5 ꢀC. 1H NMR
28.72 mg, 67% yield. Colorless oil. 1H NMR (400 MHz, CDCl3)
(400 MHz, CDCl3)
d
7.40 (d, J ¼ 7.4 Hz, 2H), 7.33e7.18 (m, 5H), 7.15
d
7.41 (d, J ¼ 7.3 Hz, 2H), 7.33e7.14 (m, 4H), 7.00 (d, J ¼ 7.5 Hz, 1H),
6.93 (d, J ¼ 10.0 Hz, 1H), 6.86 (t, J ¼ 8.4 Hz, 1H), 5.51 (s, 1H), 5.05 (s,
1H), 3.83 (s, 2H). 13C NMR (101 MHz, CDCl3)
163.09 (d,
(d, J ¼ 7.7 Hz, 2H), 5.49 (s, 1H), 5.02 (s, 1H), 3.80 (s, 2H). 13C NMR
(101 MHz, CDCl3)
d
146.7, 140.6, 138.1, 132.0, 130.4, 128.6, 128.5,
d
127.7, 126.3, 115.0, 41.1. IR (neat, cmꢁ1) 706 (s), 778 (w), 853 (m),
898 (m), 1011 (m), 1069 (m), 1487 (s), 1626 (w), 2909 (w). HRMS
(APCI) Calcd for C15H14Clþ [MþH]þ 229.0779; Found 229.0779.
J ¼ 245.3 Hz), 161.9, 146.4, 142.3 (d, J ¼ 7.3 Hz), 140.5, 129.9 (d,
J ¼ 8.3 Hz), 129.8, 128.5, 127.7, 126.2, 124.7 (d, J ¼ 2.7 Hz), 115.8, (d,
J ¼ 21.2 Hz), 115.1, 113.2 (d, J ¼ 21.1 Hz), 41.5 (d, J ¼ 1.5 Hz). IR (neat,
cmꢁ1) 704 (m), 778 (s), 865 (w), 901 (m), 1136 (m), 1248 (s), 1486
(m), 1589 (m), 1614 (m), 2921 (w). HRMS (APCI) Calcd for C15H14Fþ
[MþH]þ 213.1074; Found 213.1071.
4.4.16. 1-Bromo-4-(2-phenylallyl)benzene (3ag)
40.03 mg, 73% yield. White solid. mp. 42.5e44.5 ꢀC. 1H NMR
(400 MHz, CDCl3)
d
7.38 (t, J ¼ 8.2 Hz, 4H), 7.32e7.18 (m, 3H), 7.09
(d, J ¼ 7.6 Hz, 2H), 5.49 (s, 1H), 5.02 (s, 1H), 3.78 (s, 2H). 13C NMR
4.4.23. 1-Methyl-3-(2-phenylallyl)benzene (3an)
(101 MHz, CDCl3)
d
146.6, 140.5, 138.6, 131.6, 130.8, 128.5, 127.8,
23.44 mg, 56% yield. Colorless oil. 1H NMR (400 MHz, CDCl3)
7.43 (d, J ¼ 7.7 Hz, 2H), 7.32e7.21 (m, 3H), 7.15 (t, J ¼ 7.5 Hz, 1H),
126.2, 120.1, 115.0, 41.2. IR (neat, cmꢁ1) 703 (m), 778 (m), 804 (m),
902 (m), 1016 (m), 1093 (m), 1492 (s), 1627 (w), 2919 (w). HRMS
(APCI) Calcd for C15H14Brþ [MþH]þ 273.0273; Found 273.0266.
d
7.07e6.96 (m, 3H), 5.49 (s, 1H), 5.01 (s, 1H), 3.79 (s, 2H), 2.30 (s, 3H).
13C NMR (101 MHz, CDCl3)
d 147.1, 141.0, 139.6, 138.0, 129.8, 128.4,
128.4, 127.6, 127.0, 126.3, 126.1, 114.7, 41.7, 21.6. IR (neat, cmꢁ1) 700
(s), 756 (m), 777 (s), 898 (m), 1028 (w), 1444 (w), 1493 (w), 1607
(w), 2917 (w). HRMS (APCI) Calcd for C16Hþ17 [MþH]þ 209.1325;
Found 209.1321.
4.4.17. 1-(2-Phenylallyl)-4-(trifluoromethyl)benzene (3ah)
32.84 mg, 60% yield. Colorless oil. 1H NMR (400 MHz, CDCl3)
d
7.51 (d, J ¼ 7.7 Hz, 2H), 7.41 (d, J ¼ 7.1 Hz, 2H), 7.37e7.15 (m, 5H),
5.53 (s, 1H), 5.05 (s, 1H), 3.89 (s, 2H). 13C NMR (101 MHz, CDCl3)
d
146.2, 143.8, 140.4, 129.3, 128.5, 127.9, 126.2, 125.4 (q, J ¼ 3.8 Hz),
4.4.24. 3-(2-Phenylallyl)benzonitrile (3ao)
115.3, 41.6. IR (neat, cmꢁ1) 705 (w), 780 (w), 820 (w), 1019 (w), 1067
(m), 1123 (m), 1163 (m), 1325 (s). HRMS (APCI) Calcd for C16H14F3þ
[MþH]þ 263.1042; Found 263.1038.
22.36 mg, 51% yield. Yellow oil. 1H NMR (400 MHz, CDCl3)
d 7.51
(s, 1H), 7.45 (d, J ¼ 7.4 Hz, 2H), 7.37 (t, J ¼ 9.1 Hz, 3H), 7.33e7.21 (m,
3H), 5.53 (s, 1H), 5.05 (s,1H), 3.86 (s, 2H). 13C NMR (101 MHz, CDCl3)
d
145.8, 141.1, 140.0, 133.5, 132.5, 130.1, 129.3, 128.6, 128.0, 126.2,
4.4.18. 4-(2-Phenylallyl)benzonitrile (3ai)
119.1, 115.6, 112.5, 41.3. IR (neat, cmꢁ1) 690 (s), 704 (s), 777 (s), 813
(s), 896 (s), 1433 (w), 1493 (w), 2223 (m), 2908 (w). HRMS (APCI)
Calcd for C16H14Nþ [MþH]þ 220.1121; Found 220.1118.
29.41 mg, 67% yield. White solid. mp. 58.4e60.0 ꢀC. 1H NMR
(400 MHz, CDCl3)
d
7.54 (d, J ¼ 7.7 Hz, 2H), 7.37 (d, J ¼ 7.2 Hz, 2H),
7.35e7.20 (m, 5H), 5.54 (s, 1H), 5.06 (s, 1H), 3.89 (s, 2H). 13C NMR
(101 MHz, CDCl3)
d
145.7, 145.4, 140.1, 132.3, 129.7, 128.6, 128.0,
4.4.25. 2-(2-Phenylallyl)benzofuran (3ap)
126.2, 119.1, 115.7, 110.2, 41.9. IR (neat, cmꢁ1) 547 (m), 708 (s), 778
(s), 818 (m), 899 (m), 1411 (m), 1601 (m), 2222 (m), 2925 (w). HRMS
(APCI) Calcd for C16H14Nþ [MþH]þ 220.1121; Found 220.1120.
11.72mg, 25% yield. White solid. mp. 72.0e73.8 ꢀC. 1H NMR
(400 MHz, CDCl3)
d 7.53e7.37 (m, 4H), 7.36e7.12 (m, 5H), 6.40 (s,
1H), 5.57 (s, 1H), 5.22 (s, 1H), 3.98 (s, 2H). 13C NMR (101 MHz, CDCl3)
d
156.9, 154.9, 143.5, 140.2, 129.0, 128.5, 127.9, 126.1, 123.5, 122.6,
4.4.19. Methyl 4-(2-phenylallyl)benzoate (3aj)
120.5, 115.5, 111.0, 103.9, 34.9. IR (neat, cmꢁ1) 699.84 (s), 777.05 (s),
834.85 (m), 855.99 (m), 901.15 (m), 1445.49 (m), 1493.92 (m),
2921.79 (w). HRMS (APCI) Calcd for C17H15Oþ [MþH]þ 235.1117;
Found 235.1123.
25.94 mg, 51% yield. White solid. mp. 42.4e45 ꢀC. 1H NMR
(400 MHz, CDCl3)
d
7.93 (d, J ¼ 7.7 Hz, 2H), 7.39 (d, J ¼ 7.3 Hz, 2H),
7.34e7.15 (m, 5H), 5.51 (s, 1H), 5.04 (s, 1H), 3.97e3.77 (m, 5H). 13
C
Please cite this article as: Z. Zhou et al., Oxidative cross-coupling of allyl(trimethyl)silanes with aryl boronic acids by palladium catalysis,
Tetrahedron, https://doi.org/10.1016/j.tet.2018.10.055

8
Z. Zhou et al. / Tetrahedron xxx (xxxx) xxx
4.4.26. 3-(2-Phenylallyl)thiophene (3aq)
4.5.3. TEMPO test experiments
11.00 mg, 27% yield. Yellow oil. 1H NMR (400 MHz, CDCl3)
d
7.44
(d, J ¼ 7.4 Hz, 2H), 7.34e7.19 (m, 4H), 7.00e6.90 (m, 2H), 5.47 (s, 1H),
5.07 (s, 1H), 3.84 (s, 2H). 13C NMR (101 MHz, CDCl3)
146.8, 140.9,
(1) No palladium catalyst: To the mixture of 1a (0.2 mmol), 2a
(0.24 mmol), BQ (10 mol%, 0.02 mmol, 2.16 mg), AgOAc (2.0
equiv, 0.4 mmol, 66.77 mg), DMSO (1.0 equiv, 0.2 mmol, 14
d
140.2, 128.7, 128.4, 127.7, 126.2, 125.4, 121.6, 114.3, 36.4. IR (neat,
cmꢁ1) 699.84 (s), 777.05 (s), 834.85 (m), 855.99 (m), 901.15 (m),
1445.49 (m), 1493.92 (m), 2921.79 (w). HRMS (APCI) Calcd for
m
L) and DMF (1 mL) was added TEMPO (5.0 equiv, 1.0 mmol,
141.25 mg) at room temperature. The resulting mixture was
heated at 80 ꢀC under air for 16 h. After workup according to
the general procedure above, GC analysis showed that 3aa
was not formed and 73% of 1a was detected (eq 3, Scheme 3).
(2) With palladium catalyst: To the mixture of 1a (0.2 mmol), 2a
(0.24 mmol), PdCl2 (5 mol%, 0.01 mmol, 1.77 mg), BQ (10 mol
%, 0.02 mmol, 2.16 mg), AgOAc (2.0 equiv, 0.4 mmol,
C
13H13Sþ [MþH]þ 201.0732; Found 201.0722.
4.4.27. (E)-(2,3-Diphenylprop-1-en-1-yl)trimethylsilane (4a)
The reaction of 1a with 2a using Ag2CO3 gave a mixture of 3aa
and 4a, which could not be separated from each other. The mixture
of 3aa and 4a was treated with methyl 4-iodobenzoate, 5 mol%
Pd(OAc)2 and Ag2CO3 in DCE at 80 ꢀC under N2 atmosphere for 8 h.
After workup and flash chromatographic purification according to
the general procedure, 4a was obtained as a yellow oil. 1H NMR
66.77 mg), DMSO (1.0 equiv, 0.2 mmol,14 mL) and DMF (1 mL)
was added TEMPO (5.0 equiv, 1.0 mmol, 141.25 mg) at room
temperature. The resulting mixture was heated at 80 ꢀC un-
der air for 16 h. After workup according to the general pro-
cedure above, GC analysis showed that 3aa was formed in
19% yield and 46% of 1a was detected (eq 3, Scheme 3).
(400 MHz, CDCl3)
d
7.38 (d, J ¼ 6.2 Hz, 3H), 7.24e7.14 (m, 7H), 6.14
(s, 1H), 4.02 (s, 2H), 0.20 (s, 9H). 13C NMR (101 MHz, CDCl3)
d
153.8,
143.3, 139.8, 130.9, 128.5, 128.4, 128.2, 127.4, 126.4, 126.0, 40.4, 0.3.
IR (neat, cmꢁ1) 475.62 (m). 698.87 (m), 749.51 (m), 858.14 (s),
1249.18 (m), 1452.66 (m), 1493.84 (m), 1596.60 (w), 2962.22 (w).
Notes
HRMS (APCI) Calcd for
267.1573.
C
18H23Siþ [MþH]þ 267.1564; Found
The authors declare no competing financial interest.
4.4.28. 2-(But-1-en-2-yl)naphthalene (6)
Acknowledgment
The compound 6 was obtained by the reaction of 1j with methyl
boronic acid under the standard conditions (Scheme 4b). Colorless
We thank the National Natural Science Foundation of China
(21502006) and Beijing Institute of Technology (BIT) for financial
support.
oil. 1H NMR (400 MHz, CDCl3)
d 7.86e7.78 (m, 4H), 7.60 (d,
J ¼ 8.4 Hz, 1H), 7.49e7.42 (m, 2H), 5.43 (s, 1H), 5.18 (s, 1H), 2.65 (q,
J ¼ 7.2 Hz, 2H), 1.17 (t, J ¼ 7.3 Hz, 3H). 13C NMR (101 MHz, CDCl3)
d
150.0, 138.9, 133.6, 132.9, 128.3, 127.9, 127.7, 126.2, 125.9, 124.8,
Appendix A. Supplementary data
124.7, 111.7, 28.3, 13.2. IR (neat, cmꢁ1) 475.44 (m), 749.91 (s), 817.36
(m), 856.72 (m), 890.75 (m), 972.93 (m), 1071.73 (m), 1624.23 (w),
2966.29 (w). HRMS (APCI) Calcd for C14Hþ15 [MþH]þ 183.1168;
Found 183.1170.
Supplementary data to this article can be found online at
https://doi.org/10.1016/j.tet.2018.10.055.
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4.4.29. 2-(Naphthalen-2-yl)allyl acetate (7)
The compound 7 was obtained by the reaction of 1j with the
pinacol methylboronate, benzylboronate or allylboronate under the
standard conditions (Scheme 4b). Yellow oil. 1H NMR (400 MHz,
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Tetrahedron, https://doi.org/10.1016/j.tet.2018.10.055

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Please cite this article as: Z. Zhou et al., Oxidative cross-coupling of allyl(trimethyl)silanes with aryl boronic acids by palladium catalysis,
Tetrahedron, https://doi.org/10.1016/j.tet.2018.10.055