Water-Promoted Palladium-Catalyzed Asymmetric Ring-Opening of Oxabenzonorbornadienes with Alkoxysilanes

Article abstract of DOI:10.1002/adsc.201901152

Water-promoted palladium-catalyzed asymmetric ring-opening (ARO) reaction of oxabenzonorbornadienes with a wide variety of alkoxysilanes has been developed in a one-pot fashion, yielding cis-1,2-dihydronaphthalen-1-ols in favourable yields (up to 98%) with gratifying enantioselectivities (up to 98% ee) under mild conditions. To the best of our knowledge, it represents the first example in the ring-opening reactions of oxabicyclic alkenes with alkoxysilanes. Furthermore, the cis-1,2-configuration of product was established by X-ray diffraction analysis, and a possible mechanism for the present catalytic ring-opening reaction was also proposed. (Figure presented.).

Full text of DOI:10.1002/adsc.201901152

Title: Water-Promoted Palladium-Catalyzed Asymmetric Ring-Opening
of Oxabenzonorbornadienes with Alkoxysilanes
Authors: Yun Tan, Yongqi Yao, Wen Yang, Qifu Lin, Guobao Huang,
Minxiong Tan, Shuqi Chen, Donghan Chen, and Dingqiao
Yang
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: Adv. Synth. Catal. 10.1002/adsc.201901152
Link to VoR: http://dx.doi.org/10.1002/adsc.201901152

10.1002/adsc.201901152
Advanced Synthesis & Catalysis
COMMUNICATION
DOI: 10.1002/adsc.201((will be filled in by the editorial staff))
Water-Promoted Palladium-Catalyzed Asymmetric Ring-
Opening of Oxabenzonorbornadienes with Alkoxysilanes
Yun Tan,a Yongqi Yao,a Wen Yang,a Qifu Lin,a Guobao Huang,b Minxiong Tan,b Shuqi
Chen,a Donghan Chen,a and Dingqiao Yang*a
a
Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, College of Chemistry, South China
Normal University, Guangzhou 510006, People’s Republic of China
Fax: (+86)-20-31040403; Phone: (+86)-20-85210087; E-mail: yangdq@scnu.edu.cn
Key Laboratory of Agricultural Resources Chemistry and Biotechnology, College of Chemistry and Food Science of
b
Yulin Normal University, Yulin 537000, People’s Republic of China
Received: ((will be filled in by the editorial staff))
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.201######.((Please
delete if not appropriate))
reaction of oxabicyclic alkenes with 2-halogenated
arylboronic reagents, which generated
Abstract:
asymmetric
oxabenzonorbornadienes with
Water-promoted
ring-opening
palladium-catalyzed
(ARO) reaction of
wide variety of
a
dihydrobenzofuran products in good yields (up to
67%) with high enantioselectivities (up to 96% ee)
(Scheme 1, 1a).[10] In 2014, Suginome and co-
workers described chiral palladacycle-catalyzed ARO
of oxabicyclic alkenes with arylboronic acids to
obtain the chiral oxazolidinone products (24–94%
yields, 53–94% ees) (Scheme 1, 1b).[5d]
alkoxysilanes has been developed in a one-pot fashion,
yielding cis-1,2-dihydronaphthalen-1-ols in favourable
yields (up to 98%) with gratifying enantioselectivities
(up to 98% ee) under mild conditions. To the best of our
knowledge, it represents the first example in the ring-
opening reactions of oxabicyclic alkenes with
alkoxysilanes. Furthermore, the cis-1,2-configuration of
product was established by X-ray diffraction analysis,
and a possible mechanism for the present catalytic ring-
opening reaction was also proposed.
Inspired by Lautens's studies, we have successfully
carried out some researches in the field of ARO
reaction of different carboanion nucleophiles to oxa-
and azabicyclic alkenes. In 2014, we extended the
nickel-catalyzed ARO of oxabenzonorbornadienes
with arylboronic acids, which generated cis-1,2-ring-
opening products in high yields (up to 99%) with
excellent enantioselectivities (up to 99% ee) (Scheme
1, 1c).[11] Later, the platinum(II)-catalyzed ARO
Keywords: Water Promotion; Palladium Catalys;
Asymmetric Ring-Opening; Oxabenzonorbornadienes;
Alkoxysilanes; One-Pot Reaction
reaction
of
arylboronic
acids
to
oxabenzonorbornadienes was developed. The catalyst
showed high catalytic activity (up to 97% yield) and
asymmetric induced ring-opening (up to 89% ee)
(Scheme 1, 1d).[12] However, there were still some
limitations, for example, the reaction operation was
complicated and the nucleophilic reagent was one
fold. Therefore, it was a challenging task to explore
the other carboanion nucleophiles.
Compared to arylboronic acids and other
carboanion nucleophile, alkoxysilanes are an ideal
class of carboanion nucleophiles, which are low
toxicity, nontoxic by-products, structural diversity,
air stable and water insensitive. It can be
desiliconized and formed a carboanion nucleophilic
reagent in the cross-coupling reaction. In addition, in
our previous studies, water played an important role
in the ring-opening, cycloaddition and addition
reaction with oxa(aza)bicyclic alkenes,[13] which in a
sense greatly improved the yields of the desired
The 1,2-dihydronaphthalene skeleton is found in a
wide range of naturally occurring compounds with
different biological activities.[1] The transition-metal-
catalyzed asymmetric ring-opening (ARO) of oxa-
and azabicyclic alkenes is an effective method to
construct 1,2-dihydronaphthalenes with new carbon-
carbon or carbon-heteroatom bonds.[2] In addition, the
transformations are valuable because multiple
stereocenters can be established in one step. In this
regard, some transition-metal catalysts, including Ir,[3]
Ni,[4] Pd,[5] Cu,[6] Rh[7] ect.[8] had been investigated for
ARO reaction of heterobicyclic alkenes with various
heteroatom and carboanion nucleophilic reagents.
Various reagents, such as organic halides, alkynes,
Grignard reagents, zirconium reagents and
arylboronic acids[9] have been found as feasible
carboanion nucleophiles to construct containing aryl
and alkyl ring-opening products. In 2012, Lautens
and co-workers reported the Rh/Pd-catalyzed ARO
1
This article is protected by copyright. All rights reserved.

10.1002/adsc.201901152
Advanced Synthesis & Catalysis
products. Herein, we report a new, versatile and
efficient water-promoted palladium-catalyzed ARO
reaction of oxabenzonorbornadienes with alkyl,
alkenyl and aryl trialkoxysilanes in a one-pot fashion,
which afford the corresponding products of cis-1,2-
dihydronaphthalen-1-ol in good to excellent yields
(up to 98%) with high enantioselectivities (up to 98%
ee).
entries 2–6). In addition, various types of solvents
were also tested (Table 2, entries 6–12). If the ratio of
the mixed solvent was consisted of 1:3 (v/v) of water
and polar solvent CH3CN, the protic solvent i-PrOH,
the dipolar aprotic solvent dimethyl formamide
(DMF) and the aromatic solvent toluene, respectively,
the result of enantioselectivities increased slightly
and the yield decreased significantly (Table 2, entries
7–10). Therefore, the optimum ratio of the mixed
solvent was consisted of DCE and water (3:1, v/v)
(98% yield, 65% ee) (Table 2, entry 6). However,
enantiomeric excess of the product 3aa increased
slightly (67% ee), but the yield declined to 32% when
DCE was used as solvent (Table 2, entry 11). And the
yield and enantioselectivity are greatly reduced (18%
yield, 33% ee) while water was used as the solvent
(Table 2, entry 12). Furthermore, the influence of
reaction temperature was also examined (Table 2,
entries 13–15). Room temperature for the ring-
opening reaction was the best one, providing product
3aa in 98% yield with 84% ee (Table 2, entry 14).
Therefore, the optimized reaction conditions were:
2.5% of Pd2(dba)3, 10% of (S)-(-)-SegPhos, 1 equiv.
.
of CuF2 H2O and 1.5 equiv. of phenyl
trimethoxysilane in the mixed solvents consisting of
DCE and H2O (3:1, v/v) at room temperature
overnight.
Table 1. Effects of palladium catalyst and ligand.[a]
Scheme 1. Previous reports for the ARO of
oxabenzonorbornadienes with arylboronic acids and our
present work.
We initially chose oxabenzonorbornadiene 1a and
phenyl trimethoxysilane 2a as model substrates to
start our investigation. The reaction was performed in
the presence of 2.5% mol of Pd2(dba)3 as a catalyst,
10 % mol of 2,2'-bis(diphenylphosphanyl)-1,1'-
binaphthalene (BINAP) as the ligand and 3 equiv. of
.
CuF2 H2O as an additive in the mixed solvents
consisting of 1,2-dichloroethane (DCE) and H2O (3:1,
o
v/v) at 70 C under an air atmosphere. The desired
ring-opening product 3aa was obtained in 98% yield
overnight (Table 1, entry 1). Thereafter, a series of
palladium catalysts were an effective in catalyzing
the ring-opening reaction (Table 1, entries 7–10).
Obviously, the better result, 98% yield with 65% ee,
was still achieved in the presence of Pd2(dba)3 (Table
1, entry 7).
yield
(%)
ee
entry
catalyst (mol%)
ligand
(%)[b
]
1
2
3
4
5
6
7
8
Pd2(dba)3 (2.5)
Pd2(dba)3 (2.5)
Pd2(dba)3 (2.5)
Pd2(dba)3 (2.5)
Pd2(dba)3 (2.5)
Pd2(dba)3 (2.5)
Pd2(dba)3 (2.5)
Pd(OAc)2 (5)
L1
L2
L3
L4
L5
L6
L7
L7
98
97
-
To obtain better yields and enantiomeric excess
values, the impacts of different parameters including
additives, solvents and temperatures were
subsequently investigated (Table 2). The results
43
-
n.r.
96
15
-
.
displayed that the CuF2 H2O was the optimal additive
n.r.
98
(98% yield, 65% ee). If the fluoride salt was not
added, the reaction was not occurred (Table 2, entry
1). Different fluoride salts as the additives have a
little effect on the enantiomeric excess of the product,
but their have a greater impact on the yields (Table 2,
7
98
65
61
50
2
This article is protected by copyright. All rights reserved.

10.1002/adsc.201901152
Advanced Synthesis & Catalysis
9
Pd(PPh3)4 (5)
L7
L7
70
42
66
49
Under the optimized reaction conditions, a series
of aryl, alkenyl and alkyl trialkoxysilanes were
performed to evaluate their effects on the reactivity
10
Pd(PPh3)2Cl2 (5)
[a]
Reaction conditions: palladium catalyst, ligand L1−L7
and
enantioselectivity
(Table
3).
Phenyl
.
(10 mol%), CuF2 H2O (1 equiv.), substrate 1a (0.2 mmol),
phenyl trimethoxysilane 2a (0.3 mmol), DCE : H2O = 3:1
(v/v) (3.0 mL), 70 oC, under an air atmosphere overnight.
[b] Determined by HPLC with a chiralcel OD-H column.
trimethoxysilane 2a as nucleophilic reagent gave the
corresponding product 3aa in high yield (98%) with
good enantioselectivity (84% ee) (Table 3, entry 1).
On the contrary, alkenyl and alkyl trialkoxysilanes as
the nucleophiles gave the corresponding product 3 in
the lower yields with good enantioselectivities due to
their weak activity (Table 3, entries 3–4). For
example, the reaction of substrate 1a with benzyl
triethoxysilane 2d gave the corresponding product
3ad in 28% yield with 98% ee (Table 3, entry 4).
Unfortunately, owing to the steric hindrance,
naphthyl trimethoxysilane 2e as nucleophilic reagent
can only achieve product 3ae with moderate yield
(54%) and very low ee (7% ee) (Table 3, entry 5). In
Table 2. Optimization of additive, solvent and
temperature.[a]
tem
solvent
(v/v)
yield
(%)
ee
entry
additive
p.
(%)[d]
addition,
cyclohexyl
triethoxysilane
2f
as
(oC)
nucleophilic reagent did not react with substrate 1a
because of its low activity and the larger steric
hindrance (Table 3, entry 6). Moreover, we also
screened the effect of temperature on the less active
alkoxysilanes. (Table 3, entry 3). The reaction of
oxabenzonorbornadiene 1a with vinyl triethoxysilane
2c gave the corresponding product 3ac in lower yield
of 7% with 79% ee at room temperature. While the
DCE:H2O
(3:1)
1
2
-
70
70
70
70
70
70
70
-
-
DCE:H2O
(3:1)
TBAF[b]
NH4F
32
20
<5
59
98
35
63
64
-
DCE:H2O
(3:1)
3
DCE:H2O
(3:1)
o
temperature was 90 C, the corresponding product
4
CsF
3ac was obtained in lower yield of 17% with 79% ee.
Therefore, when temperature at 70 oC was the best
one, providing product 3ac in 36% yield with 74% ee.
DCE:H2O
(3:1)
5[c]
6
AgSbF6
CuF2⋅H2O
CuF2⋅H2O
64
65
71
DCE:H2O
(3:1)
Table
3.
Palladium-catalyzed
ARO
of
oxabenzonorbornadiene 1a with various alkoxysilanes 2.[a]
MeCN:H2
O (3:1)
7
i-
8
CuF2⋅H2O PrOH:H2O
70
29
72
(3:1)
DMF:H2O
CuF2⋅H2O
yield
(%)
ee
9
70
70
30
32
79
73
entry
R, R1
prod.
3aa
(3:1)
(%)[d]
PhMe:H2O
CuF2⋅H2O
2a: R = CH3,
R1 = C6H5
10
(3:1)
1
2
98
84
11
12
CuF2⋅H2O
CuF2⋅H2O
DCE
H2O
70
70
32
18
67
33
2b: R = CH3,
R1 = 4-CH3C6H4
89
84
3ab
DCE:H2O
(3:1)
36[b]
(7)
[17][c]
74[b]
(79)
[79][c]
13
50
r.t.
0
98
98
45
72
84
64
CuF2⋅H2O
CuF2⋅H2O
CuF2⋅H2O
2c: R = CH2CH3,
3
3ac
R1 = vinyl
DCE:H2O
(3:1)
14
2d: R = CH2CH3,
R1 = CH2C6H5
2e: R = CH3,
R1 = 1-naphthyl
2f: R = CH2CH3,
R1 = cyclohexyl
DCE:H2O
(3:1)
15
4[b]
5
28
54
98
3ad
3ae
3af
[a]
Reaction conditions: Pd2(dba)3 (2.5 mol%), (S)-(-)-
SegPhos (10 mol%), additive (1 equiv.), substrate 1a (0.2
mmol), phenyl trimethoxysilane 2a (0.3 mmol), solvent
7
-
[b]
6[b]
n. r.
(3.0 mL), under an air atmosphere overnight.
Tetrabutylammonium fluoride (TBAF). [c] The additive is
10 mol%. [d] Determined by HPLC with a chiralcel OD-H
column.
[a]
Reaction conditions: Pd2(dba)3 (2.5 mol%), (S)-(-)-
SegPhos (10 mol%), CuF2⋅H2O (1 equiv.), substrate 1a
(0.2 mmol), alkoxysilanes 2 (0.3 mmol), DCE:H2O = 3:1
(v/v) (3.0 mL), r. t., under an air atmosphere overnight. [b]
o
[c]
Reaction temperature is 70 C. Reaction temperature is
3
This article is protected by copyright. All rights reserved.

10.1002/adsc.201901152
Advanced Synthesis & Catalysis
90 oC.[d] Determined by HPLC with a chiralcel OD-H
column.
SegPhos (10 mol%), CuF2⋅H2O (1 equiv.), substrates 1b–1i
(0.2 mmol), alkenyl or aryl trialkoxysilanes 2 (0.3 mmol),
DCE:H2O = 3:1 (v/v) (3.0 mL) at room temperature
o
overnight. [b] Reaction temperature is 70 C. [c] Determined
Furthermore, the scope of substrates 1b–1i were
also explored (Table 4). Except for substrate 1a, all
oxabenzonorbornadienes 1b–1g with different
substituents on the phenyl ring reacted smoothly with
various alkenyl and aryl trialkoxysilanes 2 to generate
the ring-opening product 3 in high yields (up to 92%
yield) with good to excellent enantioselectivities (up
to 92% ee). The results listed in Table 4 that the
derivatives of substrate 1 either containing electron-
withdrawing or electron-donating groups on the aryl
rings has less influence on the enantioselectivity, but
the yields were greatly influenced. For example,
substrate 1e reacted with phenyl trimethoxysilane 2a
to provide the corresponding product 3ea in 41%
yield with 84% ee, whereas substrate 1c with phenyl
trimethoxysilane 2a afforded the corresponding
product 3ca in 65% yield with 86% ee. Furthermore,
the reaction enantioselectivity of naphthyl
trimethoxysilane 2e with various substrates 1 was
unsatisfactory. Substrate 1b reacted with naphthyl
trimethoxysilane 2e to form the corresponding
product 3be in 71% yield with the lower 9% ee.
However, the desired products 3ha and 3ia could not
be obtained by using azabenzonorbornadienes 1h–1i
as substrates. The absolute configuration of product
3eb was assigned as (1S, 2R) and determined as a cis-
1,2-configuration by X-ray diffraction analysis (see
Supporting Information for details).[14]
by HPLC with a chiralcel OD-H or chiralpak AD-H
column.
The ARO reaction was also carried out on a gram
scale to highlight the utility of this reaction system.
As shown in Scheme 2, we successfully isolated 1.38
g of the target product 3aa (89% yield, 84% ee),
which indicated the efficient nature of the synthetic
utility of this transformation.
Scheme 2. Gram-scale experiment.
Based on the experimental observation and the
general mechanism of desilication reactions,[15-17]
a
possible mechanism for the palladium-catalyzed ARO
reaction was also proposed, as shown in Scheme 3.
Firstly, the active chiral palladium(0) catalyst A was
formed by replacing the dibenzylideneacetone (dba)
ligand of the catalyst precursor Pd2(dba)3 through (S)-
(-)-SegPhos. Then, oxidative addition of palladium(0)
.
catalyst A and CuF2 H2O with substrate 1a formed
intermediate B. The intermediate B was further
rearranged to (π-allyl)-palladium(II) intermediate C.
In addition, the fluorinated intermediate G was
rationally generated from the alkyl, alkenyl and aryl
Table 4. Scope of palladium-catalyzed ARO of
oxabenzonorbornadienes 1 with various alkenyl and aryl
alkoxysilanes 2.[a]
.
trialkoxysilanes 2 activated by CuF2 H2O, which
experienced oxidation of intermediate C to produce
(hydrocarbyl)(π-allyl)-palladium(II) intermediate D.
And the alkyl, alkenyl and aryl trialkoxysilanes 2 also
proceeded through desilication by water to give the
fluorinated intermediate H at the same time, which
underwent oxidation by intermediate C to form
(hydrocarbyl)(π-allyl)-palladium(II) intermediate D.
Then, reductive elimination of intermediate D
afforded the intermediate E and regenerated the Pd(0)
species for the next catalytic cycle. Finally, the
intermediate E protonolysis with water produced the
target product 3.
[a]
Reaction conditions: Pd2(dba)3 (2.5 mol%), (S)-(-)-
4
This article is protected by copyright. All rights reserved.

10.1002/adsc.201901152
Advanced Synthesis & Catalysis
We gratefully thank the National Natural Science
Foundation of China (21172081, 21372090), the
Natural Science Foundation of Guangdong Province
(S2013020013091) and the City of Guangzhou Science
and Technology Plan Projects (201510010054) for
financial support.
References
[1] a) P. Roberto, B. Francesco, C. A. Nicola, L. Marcello,
T. Vincenzo, F. Francesco, O. Vincenzo, G. Alberto, G.
Stefano, J. Med. Chem. 1995, 38, 942–949; b) E. S.
Scott, A. A. Felix, C. Ratna, E. N. David, J. W. Val, B.
M. Richard, J. Med. Chem. 1995, 38, 2395–2409; c) M.
Lautens, T. Rovis, J. Org. Chem. 1997, 62, 5246–5247;
d) M. Lautens, T. Rovis, J. Am. Chem. Soc. 1997, 119,
11090–11091; e) M. Lautens, K. Fagnou, M. Taylor, T.
Rovis, J. Organomet. Chem. 2001, 624, 259–270; f) M.
Lautens, K. Fagnou, V. Zunic, Org. Lett. 2002, 4, 3465-
3468; g) H. A. McManus, M. J. Fleming, M. Lautens,
Angew. Chem. Int. Ed. 2007, 46, 433–436; h) J. Tsoung,
K. Krꢀmer, A. Zajdlik, C. Liꢁbert, M. Lautens, J. Org.
Chem. 2011, 76, 9031–9045.
Scheme 3. Proposed mechanism for the ring-opening
oxabicyclic alkene 1a with alkoxysilane 2.
In summary, we have developed a new, versatile
and highly efficient water-promoted palladium-
catalyzed ARO reaction of oxabenzonorbornadienes
with alkyl, alkenyl and aryl trialkoxysilanes in a one-
pot fashion. This is the first report that alkyl, alkenyl
and aryl trialkoxysilanes were used as the carboanion
nucleophilic reagents for ARO reactions of
oxabicyclic alkenes and it provides a mild reaction
condition and a convenient pathway to synthesize cis-
1,2-dihydronaphthalen-1-ol products containing aryl,
alkenyl and alkyl groups in high yields with good
enantioselectivities. Compared with the previous Co,
Pt and Ni catalysts, this catalyst system was not only
air stable and water-insensitive but also lower catalyst
loading and higher efficiency and enantioselectivity
as well as better functional group tolerance. Further
investigations are underway to explore the range of
carboanion nucleophiles in the ARO reaction.
[2] a) R. S. Ward, Chem. Soc. Rev. 1990, 19, 1–19; b) K.
Fagnou, M. Lautens, Chem. Rev. 2003, 103, 169-196; c)
T. Hayashi, K. Yamasaki, Chem. Rev. 2003, 103, 2829–
2844; d) M. Lautens, K. Fagnou, S. Hiebert, Acc. Chem.
Res. 2003, 36, 48–58.
[3] a) D. Yang, Y. Long, H. Wang, Z. Zhang, Org. Lett.
2008, 10, 4723–4726; b) X. Yang, W. Yang, Y. Yao, Y.
Deng, X. Zuo, D. Yang, Org. Chem. Front. 2018, 6,
1151–1156.
[4] a) D. K. Rayabarapu, C.-F. Chiou, C.-H. Cheng, Org.
Lett. 2002, 4, 1679–1682; b) L.-P. Li, D. K.
Rayabarapu, M. Nandi, C.-H. Cheng, Org. Lett. 2003, 5,
1621–1624; c) S. Mannathana, C.-H. Cheng, Adv. Synth.
Catal. 2014, 356, 2239–2246; d) P. Shukla, A. Sharma,
B. Pallavi, C.-H. Cheng, Tetrahedron 2015, 71, 2260–
2266; e) Y. Deng, W. Yang, Y. Yao, X. Yang, X. Zuo, D.
Yang, Org. Biomol. Chem. 2018, 17, 703–711.
Experimental Section
[5] a) S. Cabrera, R. G. Arrayás, J. C. Carretero, Angew.
Chem. Int. Ed. 2004, 43, 3944–3947; b) T.-K. Zhang,
D.-L. Mo, L.-X. Dai, X.-L. Hou, Org. Lett. 2008, 10,
3689–3692; c) S. Liu, S. Li, H. Chen, Q. Yang, J. Xu, Y.
Zhou, M. Yuan, W. Zeng, B. Fan, Adv. Synth. Catal.
2014, 356, 2960–2964; d) T. Yamamoto, Y. Akai, M.
Suginome, Angew. Chem. Int. Ed. 2014. 53, 12785–
12788; e) S. Li, J. Xu, B. Fan, Z. Lu, C. Zeng, Z. Bian,
Y. Zhou, J. Wang, Chem. Eur. J. 2015, 21, 1–6; f) Z. Lu,
J. Wang, B. Han, S. Li, Y. Zhou, B. Fan, Adv. Synth.
Catal. 2015, 357, 3121–3125; g) H. Zhou, J. Li, H.
Yang, C. Xia, G. Jiang, Org. Lett. 2015, 17, 4628–4631.
All experiments were carried out under an air atmosphere.
Pd2(dba)3 (2.5 mol%), (S)-(-)-SegPhos (10 mol%),
.
CuF2 H2O (1 equiv.), oxabenzonorbornadienes 1 (0.2
mmol), alkoxysilanes 2 (0.3 mmol), and DCE:H2O = 3:1
(v/v) (3.0 mL) as the mixed solvents were simultaneously
added to a 10.0 mL round-bottomed flask and stirred at
room termperature or 70 oC overnight. After extracted with
dichloromethane (3×10 mL) from reaction mixture, the
organic layers were combined, dried with anhydrous
MgSO4, and then filtered. The filtrate was concentrated
under vacuum, and the resulting residue was purified by
column chromatography on silica gel (200–300 mesh)
using ethyl acetate/petroleum ether as eluent to afford the
desired product 3.
[6] a) F. Bertozzi, M. Pineschi, F. Macchia, L. A. Arnold,
A. J. Minnaard, B. L. Feringa, Org. Lett. 2002, 4,
2703–2705; b) R. G. Arrayas, S. Cabrera, J. C.
Carretero, Org. Lett. 2005, 7, 219–221; c) W. Zhang,
L.-X. Wang, W.-J. Shi, Q.-L. Zhou, J. Org. Chem.
2005, 70, 3734–3736; d) W. Zhang, S.-F. Zhu, X.-C.
Qiao, Q.-L. Zhou, Chem. Asian J. 2008, 3, 2105–2111;
Acknowledgements
5
This article is protected by copyright. All rights reserved.

10.1002/adsc.201901152
Advanced Synthesis & Catalysis
e) R. Millet, T. Bernardez, L. Palais, A. Alexakis,
[12] X. Pan, G. Huang, Y. Long, X. Zuo, X. Xu, F. Gu, D.
Tetrahedron Lett. 2009, 50, 3474–3477; f) R. Millet, L.
Gremaud, T. Bernardez, L. Palais, A. Alexakis,
Synthesis 2009, 12, 2101–2112; g) P. H. Bos, A.
Rudolph, M. Pérez, M. Fañanás-Mastral, S. R.
Harutyunyan, B. L. Feringa, Chem. Commun. 2012, 48,
1748–1750.
Yang, J. Org. Chem. 2014, 79, 187–196.
[13] a) X. Yang, W. Yang, Y. Yao, Y. Deng, X. Zuo, D.
Yang, J. Org. Chem. 2018, 83, 10097–10106; b) W.
Chen, W. Yang, R. Wu, D. Yang, Green Chem. 2018,
20, 2512–2518; c) Y. Yao, W. Yang, C. Wang, F. Gu,
W. Yang, D. Yang, Asian J. Org. Chem. 2019, 8,
506–513; d) Y. Yao, W. Yang, Q. Lin, W. Yang, H.
Li, L. Wang, F Gu, D. Yang, Org. Chem. Front. 2019,
6, 3360–3364.
[7] a) P. Leong, M. Lautens, J. Org. Chem. 2004, 69,
2194–2196; b) Y.-H. Cho, V. Zunic, H. Senboku, M.
Olsen, M. Lautens, J. Am. Chem. Soc. 2006, 128,
6837–6846; c) T. Nishimura, E. Tsurumaki, T.
Kawamoto, X.-X. Guo, T. Hayashi, Org. Lett. 2008, 10,
4057–4060; d) G. C. Tsui, M. Lautens, Angew. Chem.
Int. Ed. 2012, 51, 5400–5404; (e) J. Zhu, G. C. Tsui, M.
Lautens, Angew. Chem. Int. Ed. 2012, 51, 12353–12356;
f) G. C. Tsui, N. M. Ninnemann, A. Hosotani, M.
Lautens, Org. Lett. 2013, 15, 1064–1067; g) L. Zhang,
C. M. Le, M. Lautens, Angew. Chem. Int. Ed. 2014, 53,
5951–5954.
[14] CCDC 1943431 (3eb) contains the supplementary
crystallographic data for this paper, which can be
obtained free of charge from the Cambridge
Crystallographic Data Centre.
[15] R. Lerebours, C. Wolf, Org. Lett. 2007, 9, 2737–2740.
[16] a) T. Nishikata, Y. Yamamoto, N. Miyaura, Chem. Lett.
2003, 32, 752–753; b) Z. Ye, F. Chen, F. Luo, W.
Wang, B. Lin, X. Jia, J. Cheng, Synlett. 2009, 13,
2198–2200; c) F. Luo, C. Pan, P. Qian, J. Cheng, J.
Org. Chem. 2010. 75, 5379–5381; d) D. Srimani, A.
Bej, A. Sarkar, J. Org. Chem. 2010, 75, 4296–4299; e)
T. Chatterjee, R. Dey, B. C. Ranu, New J. Chem. 2011,
35, 1103–1110; f) T. Mino, M. Shibuya, S. Suzuki, K.
Hirai, M. Sakamoto, T. Fujita, Tetrahedron 2012, 68,
429–432; g) Y. Monguchi, T. Yanase, S. Mori, H.
Sajiki, Synthesis 2013, 45, 40–44; h) H.-Q. Luo, W.
Dong, Synthetic Commun. 2013, 43, 2733–2738.
[8] a) Y. Sawama, K. Kawamoto, H. Satake, N. Krause, Y.
Kita, Synlett. 2010, 14, 2151–2155; b) Y. Huang, C. Ma,
Y. Lee, R.-Z. Huang, Y. Zhao, Angew. Chem. Int. Ed.
2015, 54, 13696–13700.
[9] a) M. Lautens, S. Ma, J. Org. Chem. 1996, 61, 7246–
7247; b) C.-C. Feng, M. Nandi, T. Sambaiah, C.-H.
Cheng, J. Org. Chem. 1999, 64, 3538–3543; c) D. K.
Rayabarapu, C.-F. Chiou, C.-H. Cheng, Org. Lett. 2002,
4, 1679–1682; d) M.-S. Wu, D. K. Rayabarapu, C.-H.
Cheng, J. Org. Chem. 2004, 69, 8407–8412; e) M.-S.
Wu, M. Jeganmohan, C.-H. Cheng, J. Org. Chem. 2005,
70, 9545–9550; f) S. Mannathan, C.-H. Cheng, Chem.
Commun. 2013, 49, 1557–1559; g) R. Wu, W. Yang, W.
Chen, D. Yang, Org. Chem. Front. 2017, 4, 1921–1925.
[17] a) F. Yang, J. Chen, J. Xu, F. Ma, Y. Zhou, M. V.
Shinde, B. Fan, Org. Lett. 2016, 18, 4832–4835; b) G.
Shen, J. Chen, D. Xu, X. Zhang, Y. Zhou, B. Fan, Org.
Lett. 2019, 21, 1364–1367; c) Y. Li, J. Chen, Z. He, H.
Qin, Y. Zhou, R. Khan, B. Fan, Org. Chem. Front.
2018, 5, 1108–1112; d) W. Zhang, J. Chen, G. Zeng, F.
Yang, J. Xu, W. Sun, M. V. Shinde, B. Fan, J. Org.
Chem. 2017, 82, 2641–2647.
[10] G. C. Tsui, J. Tsoung, P. Dougan, M. Lautens, Org.
Lett. 2012, 14, 5542–5545.
[11] Z. Zeng, D. Yang, Y. Long, X. Pan, G. Hang, X. Zuo,
W. Zhou, J. Org. Chem. 2014, 79, 5249–5257.
6
This article is protected by copyright. All rights reserved.

10.1002/adsc.201901152
Advanced Synthesis & Catalysis
COMMUNICATION
Water-Promoted Palladium-Catalyzed
Asymmetric Ring-Opening of
Oxabenzonorbornadienes with Alkoxysilanes
Adv. Synth. Catal. 2019, Volume, Page – Page
Yun Tan,a Yongqi Yao,a Wen Yang,a Qifu Lin,a
Guobao Huang,b Minxiong Tan,b Shuqi Chen,a
Donghan Chen,a and Dingqiao Yang*a
7
This article is protected by copyright. All rights reserved.