Rhodium/zinc co-catalyzed asymmetric ring opening reactions of oxabenzonorbornadienes with carboxylic acids

Article abstract of DOI:10.1016/j.tetasy.2016.11.004

The asymmetric ring opening reactions of oxabenzonorbornadienes with carboxylic acids are described. By using the complex of [Rh(COD)Cl]₂and (S,S)-BDPP, with ZnI₂as the co-catalyst, a range of aromatic acids and alkyl acids were utilized as nucleophiles to afford the corresponding chiral hydronaphthalene products with high enantioselectivities (84–94% ee). Thus, the present methodology has provides an effective synthetic method for the preparation of enantioenriched hydronaphthalenes.

Full text of DOI:10.1016/j.tetasy.2016.11.004

Tetrahedron: Asymmetry xxx (2016) xxx–xxx
Contents lists available at ScienceDirect
Tetrahedron: Asymmetry
journal homepage: www.elsevier.com/locate/tetasy
Rhodium/zinc co-catalyzed asymmetric ring opening reactions
of oxabenzonorbornadienes with carboxylic acids
a
a
a
a
a,b,
Xiaobo He a, Jingchao Chen a, , Xin Xu , Fan Yang , Cuiping Gu , Yongyun Zhou , Baomin Fan
⇑
⇑
a YMU-HKBU Joint Laboratory of Traditional Natural Medicine, Yunnan Minzu University, Yuehua Street, Kunming 650500, China
b State Key Laboratory of Elemento-organic Chemistry, Nankai University, Weijing Road, Tianjin 300071, China
a r t i c l e i n f o
a b s t r a c t
Article history:
The asymmetric ring opening reactions of oxabenzonorbornadienes with carboxylic acids are described.
By using the complex of [Rh(COD)Cl]2 and (S,S)-BDPP, with ZnI2 as the co-catalyst, a range of aromatic
acids and alkyl acids were utilized as nucleophiles to afford the corresponding chiral hydronaphthalene
products with high enantioselectivities (84–94% ee). Thus, the present methodology has provides an
effective synthetic method for the preparation of enantioenriched hydronaphthalenes.
Ó 2016 Elsevier Ltd. All rights reserved.
Received 5 September 2016
Revised 31 October 2016
Accepted 6 November 2016
Available online xxxx
1. Introduction
opening reactions of oxabenzonorbornadienes with amines. How-
ever, when we began our studies of the asymmetric ring opening
Over the past decade, the asymmetric ring opening reactions of
benzonorbornadiene derivatives have attracted continuous
interest1 as they provide straightforward access to chiral hydron-
aphthalenes, which are substructures in many biologically active
natural products and pharmaceuticals.2 Remarkable progress
towards this type of reaction has been made by Lautens et al.,3 Yang
et al.,4 and others.5 By using transition metal/Lewis acid co-catalyst
systems, our group has developed effective asymmetric ring open-
ing reactions of oxa/azabenzonorbornadienes by using terminal
alkynes,6 amines7 and phenols.8 Most recently, we turned our
attention to carboxylic acid nucleophiles. The ring opening reac-
tions of oxa/azabenzonorbornadienes by carboxylic acids have pro-
vided allyl esters as products, which are versatile reaction
substrates of Trost-Tsuji reactions.9 After Lautens et al. have pio-
neered the asymmetric ring opening reactions with carboxylate
nucleophiles,10 Yang et al. also reported this type of reaction with
iridium catalysts, but generally low enantioselectivities were
observed.11 On the basis of the successful applications of the rho-
dium/BDPP and ZnI2 co-catalyst system to the asymmetric ring
opening reactions of oxabenzonorbornadienes with amines,7b we
herein propose that this type of co-catalyst system could also be
applied to the asymmetric ring opening reactions of
oxabenzonorbornadienes by using carboxylic acids as nucleophiles.
reaction of oxabenzonorbornadienes with carboxylic acids under
previously established reaction conditions, we only observed the
generation of 1-naphthol and none of the desired product was
obtained (Table 1, entry 1). When the reaction was carried out at
60 °C, it also failed to give any of the desired product besides
1-naphthol (Table 1, entry 2). We reasoned that the generation of
1-naphthol was caused by the acidic environment and a suitable
base was needed to neutralize it,10 and also increase the nucle-
ophilicity of the carboxylic acid. The addition of 6 equivalents of
triethylamine led to a satisfactory 95% yield with 89% enantiomeric
excess (Table 1, entry 3). When screening other aprotic solvents,
we noticed that DCM, acetonitrile and ethers decreased both the
reaction yields and the enantiomeric excess (Table 1, entries
4–8). Thus, DCE was identified as the optimal reaction solvent for
present reaction.
Based on our previous study of the ring opening reactions of
oxa/azabenzonorbornadienes, Lewis acids were identified as
essential co-catalysts, which significantly enhanced the activity
of the catalytic systems. Therefore, we studied the effect of various
Lewis acids in the present reaction and the experimental results
are summarized in Table 2. Although ZnI2 was very effective, other
zinc salts such as ZnCl2, ZnBr2 and Zn(OTf)2 proved to be inferior
and lower conversions were observed even when the reaction
was carried out for a prolonged reaction time, although the ee
values remained high (Table 2, entries 2–4). Similar results were
obtained with other Lewis acids, such as AgOTf, CuBr, Cu(OTf)2,
Al(OTf)3, and AlCl3 (Table 2, entries 5–9). We noticed that the anion
of the Lewis acid also played an important role as the use of CuI
and FeI2 had afforded a yield of 59% and 73%, respectively (Table 2,
entries 10–11). We next tested Bu4NI but it only gave a low
2. Results and discussion
The complex of [Rh(COD)Cl]2 and (R,R)-BDPP has proved to be
an effective catalyst in our previous study of asymmetric ring
⇑
Corresponding authors.
http://dx.doi.org/10.1016/j.tetasy.2016.11.004
0957-4166/Ó 2016 Elsevier Ltd. All rights reserved.
Please cite this article in press as: He, X.; et al. Tetrahedron: Asymmetry (2016), http://dx.doi.org/10.1016/j.tetasy.2016.11.004

2
X. He et al. / Tetrahedron: Asymmetry xxx (2016) xxx–xxx
Table 1
Screening of reaction solventa
2+
&22+
2
>5Kꢀ&2'ꢁ&O@ꢂꢃꢄꢀ6ꢃ6ꢁꢅ%'33
2
=Q,ꢂꢃꢄ(Wꢆ1ꢃꢄVROYHQWꢃꢄꢇꢈꢄR&
2
ꢆDD
ꢉD
ꢂD
33Kꢂ
3Kꢂ3
0H
0H
ꢀ6ꢃ6ꢁꢅ%'33
Entry
Solvent
Time (h)
Yield (%)b
Ee (%)c
1d,e
2d
3
4
5
6
7
8
DCE
DCE
DCE
DCM
CH3CN
THF
Diethyl ether
1,4-Dioxane
16 h
12 h
1.5
1.5
3
1.5
4
1.5
0
0
—
—
95
82
49
89
63
67
89
88
86
80
80
76
a
The reaction was carried out with 1a (0.20 mmol), 5.0 equiv of benzoic acid 2a (1.0 mmol), 0.1 equiv of ZnI2 (0.02 mmol) and 6.0 equiv of Et3N (1.20 mmol) in solvent
(2.0 mL) at 60 °C in the presence of [Rh(COD)Cl]2 (2.5 mol %) and (S,S)-BDPP (6.5 mol %).
b
Isolated yield after silica gel column chromatography.
Determined by HPLC with a Chiralcel OD-H column.
No Et3N was used.
The reaction was carried out at room temperature.
c
d
e
Table 2
Study of the effect of Lewis acid and reaction temperaturea
2+
&22+
2
>5Kꢀ&2'ꢁ&O@ꢂꢃꢄꢀ6ꢃ6ꢁꢅ%'33
DGGLWLYHꢃꢄ(Wꢆ1ꢃꢄ'&(ꢃꢄꢇꢈꢄR&
2
2
ꢉD
ꢆDD
ꢂD
Entry
Additive
Time (h)
Yield (%)b
Ee (%)c
1
2
3
4
5
6
7
8
ZnI2
1.5
72
72
48
48
72
48
48
48
72
24
48
1.5
72
72
95
38
52
25
16
36
33
26
52
59
73
39
95
85
20
89
88
87
89
88
88
90
89
89
90
87
89
91
91
86
ZnCl2
ZnBr2
Zn(OTf)2
AgOTf
CuBr
Cu(OTf)2
Al(OTf)3
AlCl3
CuI
9
10
11
12
13d
14e
15
FeI2
nBu4NI
ZnI2
ZnI2
—
a
The reaction was carried out with 1a (0.20 mmol), 5.0 equiv of benzoic acid 2a (1.0 mmol), 0.1 equiv of Lewis acid (0.02 mmol) and 6.0 equiv of Et3N (1.20 mmol) in DCE
(2.0 mL) at 60 °C in the presence of [Rh(COD)Cl]2 (2.5 mol %) and (S,S)-BDPP (6.5 mol %).
b
Isolated yield after silica gel column chromatography.
Determined by HPLC with a Chiralcel OD-H column.
The reaction was carried out at 40 °C.
The reaction was carried out at ambient temperature.
c
d
e
reaction yield (Table 2, entry 12). The following temperature
experiments were carried out by employing ZnI2 as the Lewis acid
and a lower temperature of 40 °C proved to be beneficial to achieve
a high ee (Table 2, entry 13). When the reaction was carried out at
ambient temperature, it retained the enantioselectivity but low-
ered yield (Table 2, entry 14). It is obvious that the Lewis acid
was indispensable in present protocol, because the control experi-
ment that without any Lewis acid only gave a low reaction yield
(Table 2, entry 15).
Under the standard reaction conditions, a series of carboxylic
acids including aromatic acids and alkyl acids were subjected to
the process to investigate the reaction scope. (Table 3) In general,
all of the carboxylic acids were suitable for the present reaction
and gave good enantioselectivities (88–91%). However, the reac-
tion yields were affected by the substrates. For instance, with
OCH3, Cl, and Br on the phenyl ring of benzoic acid, the reaction
yields were suppressed by electronic characteristics (Table 3,
entries 2–4). It should be noted that the steric effect had little
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X. He et al. / Tetrahedron: Asymmetry xxx (2016) xxx–xxx
3
impact on the activity of benzoic acid (Table 3, entries 5–7). Other
aryl acids, including 2-naphthoic acid, 2-furoic acid and 2-thio-
phenecarboxylic acid were also suitable nucleophiles for present
transformations (Table 3, entries 8–10). Furthermore, we found
that a range of alkyl acids showed good reaction activities as well,
and afforded the desired products with good enantioselectivities
(Table 3, entries 11–14).
To further extend the reaction scope, a series of oxabenzonor-
bornadienes were reacted with benzoic acid and the corresponding
products were obtained in good to excellent ees (84–94%). It should
Table 3
Substrate scope of carboxylic acidsa
2+
>5Kꢀ&2'ꢁ&O@ꢂꢃꢄꢀ6ꢃ6ꢁꢅ%'33
=Q,ꢂꢃꢄ(Wꢆ1ꢃꢄ'&(ꢃꢄꢊꢈꢄR&
2
5
5
&22+
ꢂDꢅQ
2
2
ꢉD
ꢆDDꢅDQ
Entry
1
Carboxylic acid
Time (h)
1.5
Yield (%)b
95
Ee (%)c
91
2
2+
ꢂD
2
2d
16
6
68
70
68
89
90
89
2+
ꢂE
2
2
2
2+
3
ꢂF
&O
%U
2+
4
6
ꢂG
2
2
5d
6d
7d
8
4
4.5
5
90
90
88
82
90
90
90
89
2+
ꢂH
2+
ꢂI
2
2+
ꢂJ
2+
4
2
ꢂK
2
2
9
2
6
70
76
90
90
ꢂL
2+
2+
2
6
10
ꢂM
2
ꢂN
11
12
13
6
6
6
70
78
78
88
94
90
2+
2
ꢂO
2+
2
ꢂP
2+
2
14
6
73
90
2+
ꢂQ
a
The reaction was carried out with 1a (0.20 mmol), 5.0 equiv of benzoic acid 2 (1.0 mmol), 0.1 equiv of ZnI2 (0.02 mmol) and 6.0 equiv of Et3N (1.20 mmol) in DCE (2.0 mL)
at 40 °C in the presence of [Rh(COD)Cl]2 (2.5 mol %) and (S,S)-BDPP (6.5 mol %).
b
Isolated yield after silica gel column chromatography.
Determined by HPLC with a Chiralcel OD-H column.
N,N-Diisopropylethylamine was used instead of triethylamine to improve the reaction yield.
c
d
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4
X. He et al. / Tetrahedron: Asymmetry xxx (2016) xxx–xxx
be noted that the reaction of dimethyl-substituted oxabenzonor-
bornadiene 1b proceeded smoothly to afford the corresponding
ring-opening products in good yields and with excellent enantios-
electivities (Table 4, entry 2). However, the reactions were sluggish
when using oxabenzonorbornadienes 1c–e and gave 51–68% yields
with starting materials recovered (Table 4, entries 3–5). Con-
versely, oxabenzonorbornadiene 1f was found to be very active
in the presence of ZnI2 and led to the generation of 6,7-dimethoxy-
naphthalen-1-ol as a by-product with a lower yield of the desired
product (Table 4, entry 6). The bromo groups on the phenyl ring of
oxabenzonorbornadiene were tolerated under present reaction
conditions (Table 4, entry 7), which allows for further potential
functionalizations by traditional cross-coupling reactions. How-
ever, the reactions of 1h and 1i did not give the corresponding
ring-opening products under the standard conditions.
wide range of carboxylic acids were found to be suitable to give
the corresponding chiral hydronaphthalene products with high
enantioselectivities.
4. Experimental section
4.1. General
Oxabenzonorbornadienes 1a–i were prepared according to the
literature procedures.12 The reactions and manipulations were per-
formed under an atmosphere of argon by using standard Schlenk
techniques and Drybox (Mikrouna, Supper 1220/750). Anhydrous
THF (Tetrahydrofuran), diethyl ether and 1,4-dioxane were dis-
tilled from sodium benzophenone ketyl prior to use. Anhydrous
DCE (Dichloroethane) and CH3CN (acetonitrile) were distilled from
calcium hydride and stored under argon. 1H NMR and 13C NMR
spectra were recorded on Bruker-Avance 400 MHz spectrometer.
CDCl3 was used as solvent. Chemical shifts (d) are reported in
ppm with tetramethylsilane as internal standard, and J values are
given in Hz. Enantiomeric excesses were determined by Agilent
1260 Series HPLC using Daicel OD-H, OJ-H or AS-H chiral columns
eluted with a mixture of isopropyl alcohol and hexane. Melting
3. Conclusion
In conclusion, the asymmetric ring opening reactions of
oxabenzonorbornadienes were accomplished by using the rho-
dium/zinc as the co-catalyst. This co-catalytic system exhibits wide
substrate compatibility and good functional group tolerance. A
Table 4
Substrate scope of oxabenzonorbornadienesa
2+
&22+
2
3K
>5Kꢀ&2'ꢁ&O@ꢂꢃꢄꢀ6ꢃ6ꢁꢅ%'33
=Q,ꢂꢃꢄ(Wꢆ1ꢃꢄ'&(ꢃꢄꢊꢈꢄR&
5
2
5
2
ꢉDꢅJ
Oxabenzonorbornadiene
2
ꢂD
ꢆDDꢅJD
Entry
1
Time (h)
1.5
Yield (%)b
95
Ee (%)c
91
ꢉD
2
2
3
ꢉE
2
96
52
90
91
2
2
2
ꢉF
48
2
2
ꢉG
4
48
18
51
68
40
94
86
93
2
2
5d
ꢉH
2
2
2
2
ꢉI
6
1.5
2
%U
%U
2
ꢉJ
7
8
6
74
0
84
—
2
2
&220H
&220H
72
ꢉK
ꢉL
9
16
0
—
20H
20H
a
The reaction was carried out with 1 (0.20 mmol), 5.0 equiv of benzoic acid 2a (1.0 mmol), 0.1 equiv of ZnI2 (0.02 mmol) and 6.0 equiv of Et3N (1.20 mmol) in DCE (2.0 mL)
at 40 °C in the presence of [Rh(COD)Cl]2 (2.5 mol %) and (S,S)-BDPP (6.5 mol %).
b
Isolated yield after silica gel column chromatography.
Determined by HPLC with a Chiralcel OD-H, OJ-H or AS-H column.
The reaction was carried out with 1e (0.20 mmol), 0.2 equiv of ZnI2 (0.02 mmol) and 6.0 equiv of Et3N (1.20 mmol) in DCE (2.0 mL) at 40 °C in the presence of [Rh(COD)
c
d
Cl]2 (5.0 mol %) and (S,S)-BDPP (13 mol %) with 5.0 equiv of benzoic acid 2a (1.0 mmol) added dropwise during 0.5 h.
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X. He et al. / Tetrahedron: Asymmetry xxx (2016) xxx–xxx
5
points were measured on X-4 melting point apparatus and are
uncorrected. High resolution mass spectra (HRMS) were performed
on a VG Autospec-3000 spectrometer. Column chromatography
was performed with silica gel (200–300 mesh) with petroleum
ether and ethyl acetate as eluents. The absolute configurations
were assigned by comparison of the chiral HPLC data of 3ak with
that reported in the literature.10
2.59 (d, J = 6.0 Hz, 1H). The ee of 3ad was determined by HPLC anal-
ysis using Daicel Chiralcel OD-H column (25 cm ꢀ 0.46 cm ID),
conditions: n-hexane/i-PrOH = 90/10, 1.0 mL/min, 254 nm;
tminor = 9.4 min, tmajor = 16.2 min.
4.2.5. (1S,2S)-1-Hydroxy-1,2-dihydronaphthalen-2-yl 4-methyl-
benzoate 3ae
White solid; 84% yield; 90% ee; 1H NMR (400 MHz, CDCl3): d
7.96 (d, J = 7.7 Hz, 2H), 7.61 (d, J = 6.7 Hz, 1H), 7.31 (t, J = 7.8 Hz,
3H), 7.24 (s, 1H), 7.14 (d, J = 6.1 Hz, 1H), 6.57 (d, J = 9.8 Hz, 1H),
5.98 (dd, J = 10.0, 2.8 Hz, 1H), 5.87 (d, J = 9.3 Hz, 1H), 5.13 (d,
J = 9.2 Hz, 1H), 2.43 (s, 1H), 2.42 (s, 3H). The ee of 3ae was deter-
mined by HPLC analysis using Daicel Chiralcel OD-H column
(25 cm ꢀ 0.46 cm ID), conditions: n-hexane/i-PrOH = 90/10,
1.0 mL/min, 254 nm; tminor = 8.6 min, tmajor = 13.2 min.
4.2. General procedure for the asymmetric ring opening
reactions
At first, [Rh(COD)Cl]2 (2.4 mg, 0.0049 mmol), (S,S)-BDPP
(5.7 mg, 0.013 mmol) and 1.0 mL DCE were added to a Schlenk
tube under an argon atmosphere. Then ZnI2 (6.4 mg, 0.02 mmol)
was added and the mixtures were stirred for 10 min. After the
addition of Et3N (166 lL, 1.2 mmol) and oxabenzonorbornadiene
(0.2 mmol), the mixtures were stirred for an additional 10 min.
Then, a solution of carboxylic acid (1.0 mmol) in DCE (1.0 mL)
was added, and the mixtures were stirred at 40 °C under argon
atmosphere with TLC monitoring until the complete consumption
of oxabenzonorbornadiene. The reaction mixture was concen-
trated, and the residue was purified by chromatography on a silica
gel column to afford the desired ring opening product. The enan-
tiomeric excess value of the product was determined by HPLC on
a chiral stationary phase.
4.2.6. (1S,2S)-1-Hydroxy-1,2-dihydronaphthalen-2-yl 3-methyl-
benzoate 3af
White solid; 90% yield; 90% ee; mp 107–108 °C; ½a D21
ꢁ
= +315
d 7.87 (d,
(c = 0.316, CH2Cl2); 1H NMR (400 MHz, CDCl3):
J = 9.0 Hz, 2H), 7.61 (d, J = 6.2 Hz, 1H), 7.39 (d, J = 7.4 Hz, 1H),
7.35–7.29 (m, 3H), 7.14 (d, J = 6.7 Hz, 1H), 6.57 (d, J = 9.8 Hz, 1H),
5.99 (d, J = 10.0 Hz, 1H), 5.88 (d, J = 9.2 Hz, 1H), 5.14 (d, J = 8.7 Hz,
1H), 2.56 (s, 1H), 2.41 (s, 3H); 13C NMR (CDCl3, 100 MHz): d
167.06, 138.28, 135.40, 134.10, 131.62, 130.33, 129.75, 129.60,
128.40, 128.34, 126.99, 126.77, 125.98, 125.56, 76.26, 72.13,
4.2.1. (1S,2S)-1-Hydroxy-1,2-dihydronaphthalen-2-yl benzoate
3aa
21.27; MS (ESI) calcd for C
18H16O3 (M+): 280.1099; Found:
280.1099 (M+). The ee of 3af was determined by HPLC analysis
using Daicel Chiralcel OD-H column (25 cm ꢀ 0.46 cm ID),
conditions: n-hexane/i-PrOH = 90/10, 1.0 mL/min, 254 nm;
tminor = 8.8 min, tmajor = 11.8 min.
White solid; 95% yield; 94% ee; 1H NMR (400 MHz, CDCl3): d
8.07 (d, J = 7.6 Hz, 2H), 7.60–7.56 (m, 2H), 7.45 (t, J = 15.1 Hz,
2H), 7.34–7.28 (m, 2H), 7.15 (d, J = 6.0 Hz, 1H), 6.58 (d, J = 9.6 Hz,
1H), 5.99 (d, J = 9.6 Hz, 1H), 5.89 (d, J = 9.0 Hz, 1H), 5.14 (d,
J = 8.8 Hz, 1H), 2.52 (s, 1H). The ee of 3aa was determined by HPLC
analysis using Daicel Chiralcel OD-H column (25 cm ꢀ 0.46 cm ID),
conditions: n-hexane/i-PrOH = 90/10, 1.0 mL/min, 254 nm;
tminor = 9.7 min, tmajor = 12.3 min.
4.2.7. (1S,2S)-1-Hydroxy-1,2-dihydronaphthalen-2-yl 2-methyl-
benzoate 3ag
White solid; 88% yield; 90% ee; 1H NMR (400 MHz, CDCl3): d
7.93 (d, J = 7.8 Hz, 1H), 7.58 (d, J = 4.7 Hz, 1H), 7.41 (t, J = 14.9 Hz,
1H), 7.30 (t, J = 7.4 Hz, 2H), 7.24 (t, J = 14.1 Hz, 2H), 7.14 (d,
J = 4.4 Hz, 1H), 6.58 (d, J = 9.8 Hz, 1H), 6.01 (d, J = 9.8 Hz, 1H),
5.85 (d, J = 8.8 Hz, 1H), 5.10 (d, J = 8.8 Hz, 1H), 2.59 (s, 3H), 2.55
(s, 1H). The ee of 3ag was determined by HPLC analysis using Dai-
cel Chiralcel OD-H column (25 cm ꢀ 0.46 cm ID), conditions: n-
hexane/i-PrOH = 90/10, 1.0 mL/min, 254 nm; tminor = 9.5 min,
tmajor = 12.3 min.
4.2.2. (1S,2S)-1-Hydroxy-1,2-dihydronaphthalen-2-yl 4-methoxy-
benzoate 3ab
White solid; 54% yield; 89% ee; 1H NMR (400 MHz, CDCl3): d
8.02 (d, J = 8.7 Hz, 2H), 7.60 (t, J = 7.8 Hz, 1H), 7.29 (t, J = 7.0 Hz,
2H), 7.13 (t, J = 8.2 Hz, 1H), 6.91 (d, J = 8.7 Hz, 2H), 6.55 (d,
J = 9.8 Hz, 1H), 5.97 (dd, J = 9.6, 2.4 Hz, 1H), 5.85 (d, J = 9.1 Hz,
1H), 5.13–5.10 (m, 1H), 3.86 (s, 3H), 2.77 (d, J = 4.9 Hz, 1H). The
ee of 3ab was determined by HPLC analysis using Daicel
Chiralcel OD-H column (25 cm ꢀ 0.46 cm ID), conditions:
n-hexane/i-PrOH = 90/10, 1.0 mL/min, 254 nm; tminor = 13.8 min,
tmajor = 24.7 min.
4.2.8. (1S,2S)-1-Hydroxy-1,2-dihydronaphthalen-2-yl 2-naphth-
oate 3ah
White solid; 70% yield; 89% ee; 1H NMR (400 MHz, CDCl3): d
8.64 (s, 1H), 8.08 (d, J = 8.6 Hz, 1H), 7.95 (d, J = 8.0 Hz, 1H), 7.88
(d, J = 8.4 Hz, 2H), 7.64–7.53 (m, 3H), 7.35–7.29 (m, 2H), 7.16 (t,
J = 8.2 Hz, 1H), 6.60 (d, J = 9.8 Hz, 1H), 6.05 (dd, J = 9.6, 2.8 Hz,
1H), 5.96 (d, J = 9.1 Hz, 1H), 5.21 (d, J = 9.1 Hz, 1H), 2.65 (s, 1H).
The ee of 3ah was determined by HPLC analysis using Daicel
Chiralcel OD-H column (25 cm ꢀ 0.46 cm ID), conditions:
n-hexane/i-PrOH = 90/10, 1.0 mL/min, 254 nm; tminor = 15.2 min,
tmajor = 23.6 min.
4.2.3. (1S,2S)-1-Hydroxy-1,2-dihydronaphthalen-2-yl 4-chloro-
benzoate 3ac
White solid; 70% yield; 90% ee; 1H NMR (400 MHz, CDCl3): d
8.00 (d, J = 7.64 Hz, 2H), 7.59 (t, J = 8.0 Hz, 1H), 7.42 (d, J = 7.6 Hz,
2H), 7.31 (t, J = 7.6 Hz, 2H), 7.15 (d, J = 7.9 Hz, 1H), 6.59(d,
J = 9.8 Hz, 1H), 5.97 (dd, J = 10.0, 2.8 Hz, 1H), 5.87 (d, J = 8.9 Hz,
1H), 5.11 (d, J = 8.9 Hz, 1H). The ee of 3ac was determined by HPLC
analysis using Daicel Chiralcel OD-H column (25 cm ꢀ 0.46 cm ID),
conditions: n-hexane/i-PrOH = 90/10, 1.0 mL/min, 254 nm;
tminor = 8.8 min, tmajor = 14.5 min.
4.2.9. (1S,2S)-1-Hydroxy-1,2-dihydronaphthalen-2-yl furan-2-
carboxylate 3ai
White solid; 70% yield; 90% ee; 1H NMR (400 MHz, CDCl3): d
7.60–7.59 (m, 2H), 7.33–7.28 (m, 2H), 7.24 (dd, J = 0.5, 0.5 Hz,
1H), 7.14–7.12 (m, 1H), 6.56 (dd, J = 9.6, 1.6 Hz, 1H), 6.53–6.52
(m, 1H), 5.96 (dd, J = 9.6, 1.6 Hz, 1H), 5.85 (dt, J = 13.2, 2.0 Hz,
1H), 5.12 (d, J = 9.2 Hz, 1H), 2.54 (s, 1H). The ee of 3ai was deter-
mined by HPLC analysis using Daicel Chiralcel OD-H column
(25 cm ꢀ 0.46 cm ID), conditions: n-hexane/i-PrOH = 90/10,
1.0 mL/min, 254 nm; tminor = 7.3 min, tmajor = 9.2 min.
4.2.4. (1S,2S)-1-Hydroxy-1,2-dihydronaphthalen-2-yl 4-bromo-
benzoate 3ad
White solid; 68% yield; 89% ee; 1H NMR (400 MHz, CDCl3): d
7.90 (d, J = 8.3 Hz, 2H), 7.56 (d, J = 8.2 Hz, 3H), 7.30 (t, J = 8.5 Hz,
2H), 7.14 (t, J = 8.5 Hz, 1H), 6.57 (d, J = 9.9 Hz, 1H), 5.96(dd,
J = 9.6, 2.8 Hz, 1H), 5.86 (d, J = 8.0 Hz, 1H), 5.10 (t, J = 14 Hz, 1H),
Please cite this article in press as: He, X.; et al. Tetrahedron: Asymmetry (2016), http://dx.doi.org/10.1016/j.tetasy.2016.11.004

6
X. He et al. / Tetrahedron: Asymmetry xxx (2016) xxx–xxx
4.2.10. (1S,2S)-1-Hydroxy-1,2-dihydronaphthalen-2-yl thiophene-
i-PrOH = 90/10, 1.0 mL/min, 254 nm; tminor = 13.7 min, tmajor =
2-carboxylate 3aj
23.0 min.
White solid; 76% yield; 90% ee; mp 115–116 °C; ½a D22
ꢁ
= +296.3 (c
0.824, CH2Cl2); 1H NMR (400 MHz, CDCl3): d 7.84 (dd, J = 1.2,
1.2 Hz, 1H), 7.61–7.58 (m, 2H), 7.33–7.26 (m, 2H), 7.14–7.10 (m,
2H), 6.56 (dd, J = 10.0, 2.0 Hz, 1H), 5.97 (dd, J = 9.6, 2.8 Hz, 1H),
5.84 (dt, J = 12.4, 2.8 Hz, 1H), 5.12 (dd, J = 8.8, 3.6 Hz, 1H), 2.60
(d, J = 5.0 Hz, 1H), 13C NMR (CDCl3, 100 MHz): d 162.48, 135.32,
134.08, 133.31, 133.03, 131.58, 129.67, 128.42, 128.34, 127.89,
126.77, 125.91, 125.36, 76.72, 72.04; MS (ESI) calcd for
4.2.15. (1S,2S)-1-Hydroxy-6,7-dimethyl-1,2-dihydronaphthalen-
2-yl benzoate 3ba
White solid; 96% yield; 90% ee; 1H NMR (400 MHz, CDCl3): d
8.05 (t, J = 8.4 Hz, 2H), 7.59–7.55 (m, 1H), 7.44 (t, J = 15.4 Hz, 2H),
7.34 (s, 1H), 6.93 (s, 1H), 6.54 (dd, J = 11.0, 1.4 Hz, 1H), 5.93 (dd,
J = 9.6, 3.2 Hz, 1H), 5.84–5.80 (m, 1H), 5.07–5.04 (m, 1H), 2.28 (d,
J = 12.8 Hz, 6H), 2.44 (s, 1H). The ee of 3ba was determined by HPLC
analysis using Daicel Chiralcel OD-H column (25 cm ꢀ 0.46 cm ID),
conditions: n-hexane/i-PrOH = 90/10, 1.0 mL/min, 254 nm;
tminor = 9.8 min, tmajor = 12.5 min.
C
15H12O3S (M+): 272.0507; Found: 272.0511 (M+). The ee of 3aj
was determined by HPLC analysis using Daicel Chiralcel OD-H col-
umn (25 cm ꢀ 0.46 cm ID), conditions: n-hexane/i-PrOH = 90/10,
1.0 mL/min, 254 nm; tminor = 7.0 min, tmajor = 8.6 min.
4.2.16. (5S,6S)-5-Hydroxy-5,6-dihydronaphtho[2,3-d][1,3]dioxol-
4.2.11. (1S,2S)-1-Hydroxy-1,2-dihydronaphthalen-2-yl acetate
3ak
6-yl benzoate 3ca
White solid; 52% yield; 91% ee; mp 134–135 °C; ½a D22
ꢁ
= +195.3 (c
White solid; 82% yield; 88% ee; 1H NMR (400 MHz, CDCl3): d
7.49 (d, J = 5.8 Hz, 1H), 7.24–7.21 (m, 2H), 7.05 (d, J = 4.6 Hz, 1H),
6.46 (d, J = 9.8 Hz, 1H), 5.81 (d, J = 9.7 Hz, 1H), 5.54 (d, J = 9.0 Hz,
1H), 4.88 (d, J = 8.8 Hz, 1H), 2.28 (s, 1H), 2.07 (s, 3H). The ee of
3ak was determined by HPLC analysis using Daicel Chiralcel
OD-H column (25 cm ꢀ 0.46 cm ID), conditions: n-hexane/
0.344, CH2Cl2); 1H NMR (400 MHz, CDCl3): d 8.06 (d, J = 7.7 Hz, 2H),
7.58 (t, J = 14.7 Hz, 1H), 7.44 (t, J = 15.2 Hz, 2H), 7.11 (s, 1H), 6.65 (s,
1H), 6.46 (d, J = 9.8 Hz, 1H), 5.97 (s, 2H), 5.91 (dd, J = 10.0, 2.8 Hz,
1H), 5.81 (d, J = 8.6 Hz, 1H), 5.01 (d, J = 8.2 Hz, 1H), 2.51 (s, 1H);
13C NMR (CDCl3, 100 MHz): d 166.81, 147.57, 147.44, 133.30,
129.82, 129.79, 129.51, 128.43, 125.81, 123.40, 107.53, 107.48,
101.25, 75.91, 72.06; MS (ESI) calcd for C18H14O5 (M+): 310.0841;
Found: 310.0851 (M+). The ee of 3ca was determined by HPLC
analysis using Daicel Chiralcel OJ-H column (25 cm ꢀ 0.46 cm ID),
i-PrOH = 90/10, 1.0 mL/min, 254 nm; tminor = 8.9 min, tmajor
=
12.8 min.
4.2.12. (1S,2S)-1-Hydroxy-1,2-dihydronaphthalen-2-yl propionate
3al
conditions: n-hexane/i-PrOH = 90/10, 1.0 mL/min, 254 nm; tminor
40.7 min, tmajor = 47.8 min.
=
White solid; 78% yield; 94% ee; 1H NMR (400 MHz, CDCl3): d
7.55 (t, J = 8.1 Hz 1H), 7.27 (t, J = 8.6 Hz, 2H), 7.10 (t, J = 8.4 Hz,
1H), 6.51 (d, J = 9.8 Hz, 1H), 5.86 (dd, J = 9.6, 2.8 Hz, 1H), 5.61 (d,
J = 9.0 Hz, 2H), 4.94 (d, J = 9.0 Hz, 1H), 2.62 (s, 1H), 2.43–2.38 (m,
2H), 1.17 (t, J = 15.1 Hz, 3H). The ee of 3al was determined by HPLC
analysis using Daicel Chiralcel OD-H column (25 cm ꢀ 0.46 cm ID),
conditions: n-hexane/i-PrOH = 90/10, 1.0 mL/min, 254 nm;
tminor = 7.2 min, tmajor = 12.3 min.
4.2.17. (6S,7S)-6-Hydroxy-2,3,6,7-tetrahydronaphtho[2,3-b][1,4]
dioxin-7-yl benzoate 3da
White solid; 51% yield; 94% ee; mp 153–154 °C; ½a D21
ꢁ
= +211.2 (c
0.224, CH2Cl2); 1H NMR (400 MHz, CDCl3): d 8.05 (d, J = 7.2 Hz, 2H),
7.57 (t, J = 14.8 Hz, 1H), 7.44 (t, J = 14.5 Hz, 2H), 7.10 (s, 1H), 6.67 (s,
1H), 6.46 (dd, J = 9.6, 0.8 Hz, 1H), 5.89 (dd, J = 9.6, 3.2 Hz, 1H), 5.78
(m, 1H), 4.99 (d, J = 8.2 Hz, 1H), 4.26 (s, 4H), 2.52 (s, 1H); 13C NMR
(CDCl3, 100 MHz):
d 166.78, 143.46, 143.22, 133.26, 129.90,
4.2.13. (1S,2S)-1-Hydroxy-1,2-dihydronaphthalen-2-yl 3-methyl-
butanoate 3am
129.23, 129.22, 128.97, 128.41, 125.39, 123.54, 115.93, 75.69,
71.55, 64.49, 64.41; MS (ESI) calcd for C19H16O5 (M+): 324.0998;
Found: 324.0999 (M+). The ee of 3da was determined by HPLC
analysis using Daicel Chiralcel OJ-H column (25 cm ꢀ 0.46 cm ID),
White solid; 78% yield; 90% ee; mp 112–113 °C; ½a D22
ꢁ
= +168 (c
0.208, CH2Cl2); 1H NMR (400 MHz, CDCl3): d 7.55 (t, J = 8.2 Hz,
1H), 7.28–7.26 (m, 2H), 7.10 (t, J = 8.4 Hz, 1H), 6.51 (d, J = 9.8 Hz,
1H), 5.86 (dd, J = 10.0, 2.8 Hz, 1H), 5.63 (d, J = 9.1 Hz, 1H), 4.94 (d,
J = 9.0 Hz, 1H), 2.47 (s, 1H), 2.26 (d, J = 7.4 Hz, 2H), 2.17–2.10 (m,
1H), 0.98 (d, J = 6.6 Hz, 6H); 13C NMR (CDCl3, 100 MHz): d 173.52,
135.41, 131.61, 129.45, 128.34, 128.32, 126.73, 125.97, 125.63,
75.23, 72.01, 43.51, 25.85, 22.38; MS (ESI) calcd for C15H18O3
(M+): 246.1256; Found: 246.1260 (M+). The ee of 3am was deter-
mined by HPLC analysis using Daicel Chiralcel OD-H column
(25 cm ꢀ 0.46 cm ID), conditions: n-hexane/i-PrOH = 90/10,
1.0 mL/min, 254 nm; tminor = 6.1 min, tmajor = 10.0 min.
conditions: n-hexane/i-PrOH = 85/15, 0.5 mL/min, 254 nm; tminor
88.1 min, tmajor = 92.5 min.
=
4.2.18. (1S,2S)-1-Hydroxy-5,8-dimethoxy-1,2-dihydronaphthalen-
2-yl benzoate 3ea
White solid; 42% yield; 86% ee; 1H NMR (400 MHz, CDCl3): d
7.96 (d, J = 7.7 Hz, 2H), 7.51 (t, J = 14.6 Hz, 1H), 7.37 (t,
J = 15.2 Hz, 2H), 7.15 (d, J = 9.8 Hz, 1H), 6.84 (s, 2H), 6.16 (dd,
J = 5.0, 5.1 Hz, 1H), 5.76 (s, 1H), 5.28 (s, 1H), 3.84 (d, J = 11.9 Hz,
6H), 2.53 (s, 1H). The ee of 3ea was determined by HPLC analysis
using Daicel Chiralcel OD-H column (25 cm ꢀ 0.46 cm ID),
4.2.14. (1S,2S)-1-Hydroxy-1,2-dihydronaphthalen-2-yl 3-phenyl-
propanoate 3an
conditions: n-hexane/i-PrOH = 90/10, 1.0 mL/min, 254 nm; tminor
25.0 min, tmajor = 20.2 min.
=
White solid; 73% yield; 90% ee; mp 61–62 °C; ½a D22
ꢁ
= +146.6 (c
0.56, CH2Cl2); 1H NMR (400 MHz, CDCl3): d 7.51 (d, J = 4.4 Hz,
1H), 7.30–7.24 (m, 4H), 7.21 (t, J = 14.0 Hz, 3H), 7.09 (d,
J = 4.9 Hz, 1H), 6.48 (d, J = 9.8 Hz, 1H), 5.78 (d, J = 9.8 Hz, 1H),
5.58 (d, J = 8.9 Hz, 1H), 4.87 (d, J = 9.0 Hz, 1H), 2.97 (t, J = 15.2 Hz,
2H), 2.71 (t, J = 15.2 Hz, 2H), 2.15 (s, 1H); 13C NMR (CDCl3,
4.2.19. (1S,2S)-1-Hydroxy-6,7-dimethoxy-1,2-dihydronaphthalen-
2-yl benzoate 3fa
White solid; 40% yield; 93% ee; 1H NMR (400 MHz, CDCl3): d
8.08–8.06 (m, 2H), 7.60–7.56 (m, 1H), 7.47–7.44 (m, 2H), 7.16 (s,
1H), 6.69 (s, 1H), 6.51 (dd, J = 9.6, 1.6 Hz, 1H), 5.91 (dd, J = 9.6,
3.2 Hz, 1H), 5.85–5.82 (m, 1H), 5.06 (d, J = 8.6 Hz, 1H), 3.92 (d,
J = 16.2 Hz, 6H), 2.55 (s, 1H). The ee of 3fa was determined by HPLC
analysis using Daicel Chiralpak AS-H column (25 cm ꢀ 0.46 cm ID),
100 MHz):
d 173.11, 140.23, 135.22, 131.56, 129.47, 128.56,
126.72, 126.42, 125.91, 125.45, 75.62, 71.83, 35.97, 30.98; MS
(ESI) calcd for C19H18O3 (M+): 294.1256; Found: 294.1255 (M+).
The ee of 3an was determined by HPLC analysis using Daicel Chi-
ralcel OD-H column (25 cm ꢀ 0.46 cm ID), conditions: n-hexane/
conditions: n-hexane/i-PrOH = 80/20, 1.0 mL/min, 254 nm; tminor
31.5 min, tmajor = 20.1 min.
=
Please cite this article in press as: He, X.; et al. Tetrahedron: Asymmetry (2016), http://dx.doi.org/10.1016/j.tetasy.2016.11.004

X. He et al. / Tetrahedron: Asymmetry xxx (2016) xxx–xxx
7
Anderson, P. S.; Baldwin, J. J.; Clineschmidt, B. V.; McClure, D. E.; Lundell, G. F.;
Randall, W. C.; Martin, G. E.; Williams, M.; Hirshfield, J. M.; Smith, G.; Lumma,
P. K. J. Med. Chem. 1984, 27, 1607; (c) Boustie, J.; Stigliani, J. L.; Montanha, J.;
Amoros, M.; Payard, M.; Girre, L. J. Nat. Prod. 1998, 61, 480; (d) Wright, C. W.;
Marshall, S. J.; Russell, P. F.; Anderson, M. M.; Phillipson, J. D.; Kirby, G. C.;
Warhurst, D. C.; Schiff, P. L. J. Nat. Prod. 2000, 63, 1638; (e) Lakshman, M. K.;
Keeler, J. C.; Ngassa, F. N.; Hilmer, J. H.; Pradhan, P.; Zajc, B.; Thomasson, K. A. J.
Am. Chem. Soc. 2007, 129, 68; (f) Brastianos, H. C.; Sturgeon, C. M.; Roberge, M.;
Andersen, R. J. J. Nat. Prod. 2007, 70, 287.
4.2.20. (1S,2S)-6,7-Dibromo-1-hydroxy-1,2-dihydronaphthalen-
2-yl benzoate 3ga
White solid; 74% yield; 84% ee; 1H NMR (400 MHz, CDCl3): d
8.08 (d, J = 7.5 Hz, 2H), 7.87 (s, 1H), 7.61 (t, J = 15.1 Hz, 1H), 7.47
(t, J = 15.2 Hz, 2H), 7.38 (s, 1H), 6.46 (d, J = 9.7 Hz, 1H), 6.05 (d,
J = 9.8 Hz, 1H), 5.86 (d, J = 9.8 Hz, 1H), 5.08 (d, J = 9.8 Hz, 1H),
2.72 (s, 1H). The ee of 3ga was determined by HPLC analysis using
Daicel Chiralcel OD-H column (25 cm ꢀ 0.46 cm ID), conditions: n-
hexane/i-PrOH = 95/5, 1.0 mL/min, 254 nm; tminor = 37.4 min,
tmajor = 33.9 min.
3. (a) Lautens, M.; Fagnou, K.; Rovis, T. J. Am. Chem. Soc. 2000, 122, 5650; (b)
Lautens, M.; Fagnou, K. J. Am. Chem. Soc. 2001, 123, 7170; (c) Cho, Y. H.; Zunic,
V.; Senboku, H.; Olsen, M.; Lautens, M. J. Am. Chem. Soc. 2006, 128, 6837.
4. (a) Long, Y.-H.; Yang, D.-Q.; Zhang, Z.-M.; Wu, Y.-J.; Zeng, H.-P.; Chen, Y. J. Org.
Chem. 2010, 75, 7291; (b) Yang, D.-Q.; Long, Y.-H.; Zhang, J.-F.; Zeng, H.-P.;
Wang, S.-Y.; Li, C.-R. Organometallics 2010, 29, 3477; (c) Cheng, H.-C.; Yang, D.-
Q. J. Org. Chem. 2012, 77, 9756.
Acknowledgments
5. (a) Luo, R.-S.; Liao, J.-H.; Xie, L.; Tang, W.-J.; Chan, A. S. C. Chem. Commun. 2013,
49, 9959; (b) Jack, K.; Fatila, E.; Hillis, C.; Tam, W. Synth. Commun. 2013, 43,
1181.
6. (a) Fan, B.-M.; Li, S.-F.; Chen, H.-L.; Lu, Z.-W.; Liu, S.-S.; Yang, Q.-J.; Yu, L.; Xu, J.-
B.; Zhou, Y.-Y.; Wang, J. Adv. Synth. Catal. 2013, 355, 2827; (b) Liu, S.-S.; Li, S.-F.;
Chen, H.-L.; Yang, Q.-J.; Xu, J.-B.; Zhou, Y.-Y.; Yuan, M.-L.; Zeng, W.-M.; Fan, B.-
M. Adv. Synth. Catal. 2014, 356, 2960.
We thank the National Natural Science Foundation of China –
China (21572198, 21362043, 21302162) and the Department of
Education of Yunnan Province – China (ZD2015012) for financial
support.
7. (a) Lu, Z.-W.; Wang, J.; Han, B.-Q.; Li, S.-F.; Zhou, Y.-Y.; Fan, B.-M. Adv. Synth.
Catal. 2015, 357, 3121; (b) Xu, X.; Chen, J.-C.; He, Z.-X.; Zhou, Y.-Y.; Fan, B.-M.
Org. Biomol. Chem. 2016, 14, 2480.
A. Supplementary data
8. Li, S.-F.; Xu, J.-B.; Fan, B.-M.; Lu, Z.-W.; Zeng, C.-Y.; Bian, Z.-X.; Zhou, Y.-Y.;
Wang, J. Chem. Eur. J. 2015, 21, 9003.
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Jørgensen, K. A. Chem. Rev. 1998, 98, 1689; (c) Trost, B. M.; Crawley, M. L. Chem.
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Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.tetasy.2016.11.
004.
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Please cite this article in press as: He, X.; et al. Tetrahedron: Asymmetry (2016), http://dx.doi.org/10.1016/j.tetasy.2016.11.004