Efficient 1,2-addition of aryl- and alkenylboronic acids to aldehydes catalyzed by the palladium/thioether-imidazolinium chloride system

Article abstract of DOI:10.1021/jo7020983

(Chemical Equation Presented) The high level of catalyst performance was attainable in the palladium-catalyzed 1,2-addition of aryl-, heteroaryl-, and alkenylboronic acids to aromatic, heteroaromatic, and aliphatic aldehydes using thioether-imidazolinium chloride L5 as a heterobidentate carbene ligand precursor.

Full text of DOI:10.1021/jo7020983

phine complexes with chloroform.7 Kondo and Aoyama reported
(()-tol-BINAP-palladium complex as a chloroform-free cata-
lyst.8 Hu found palladacycles containing phosphorus donors
catalyzed addition reactions to aromatic and aliphatic aldehydes
at room temperature.9 Wu and Cheng found bulky tri(1-
naphthyl)phosphine was effective, and achieved heteroarylation
of aldehydes, in which only thienyl groups were examined.10
In spite of these efforts, examples of addition using hetero-
cyclic and sterically hindered substrates are scarce and alkeny-
lations have not been reported. Thus, it is still desirable to
develop or find more active and efficient catalytic systems for
1,2-addition of organoboronic acids to aldehydes. Herein, we
would like to describe efficient 1,2-addition reactions of aryl-,
heteroaryl-, and alkenylboronic acids to aromatic, heteroaro-
matic, and aliphatic aldehydes catalyzed by 0.005-2.0 mol %
of the palladium/thioether-imidazolinium chloride system.
First of all, the 1,2-addition of phenylboronic acid 2a to
benzaldehyde 1a using 1.0 mol % of catalysts (Pd/L )1/1)
generated in situ from thioether-imidazolinium chlorides11
L1-6 (Figure 1) and [Pd(allyl)Cl]2 in the presence of cesium
carbonate was examined in toluene at 80 °C for 20 min, and
thioether-imidazolinium chloride L5 was proven to be a
superior heterobidentate12 carbene ligand precursor (Table 1,
entries 1-6). The reaction using SIPr‚HCl (Figure 1), a simple
monodentate carbene ligand precursor, gave the addition product
3aa in only 8% yield (entry 7).
Efficient 1,2-Addition of Aryl- and
Alkenylboronic Acids to Aldehydes Catalyzed by
the Palladium/Thioether-Imidazolinium Chloride
System
Masami Kuriyama,* Rumiko Shimazawa, and
Ryuichi Shirai*
Faculty of Pharmaceutical Sciences, Doshisha Women’s College
of Liberal Arts, Kodo, Kyotanabe, Kyoto 610-0395, Japan
mkuriyam@dwc.doshisha.ac.jp; rshirai@dwc.doshisha.ac.jp
ReceiVed September 26, 2007
The high level of catalyst performance was attainable in the
palladium-catalyzed 1,2-addition of aryl-, heteroaryl-, and
alkenylboronic acids to aromatic, heteroaromatic, and ali-
phatic aldehydes using thioether-imidazolinium chloride L5
as a heterobidentate carbene ligand precursor.
In metal-mediated organic synthesis, the transmetalation
between organo-main group metal reagents and transition metal
complexes is important for the generation of active organome-
tallic species.1 Particularly, organoboronic acids are known as
useful reagents for carbon-carbon bond formations with various
electrophiles in the presence of transition metal.2 In 1998,
Miyaura and co-workers reported that 1,2-addition of arylbo-
ronic acids to aldehydes was catalyzed by rhodium(I) com-
plexes.3 Because of the advantageous features of organoboronic
acids such as low toxicity and easy manipulation2 and the
importance of the addition products as intermediates for the
synthesis of biologically active compounds,4 this type of reaction
has been attracting much attention.5 In terms of usefulness, more
economically and practically advantageous processes are desir-
able.
FIGURE 1. Precursors of N-heterocyclic carbene ligands.
A series of bases were examined, and we found cesium
fluoride was the reagent of choice (Table 1, entries 5 and 8-11).
Investigation into the influence of solvents proved that dioxane
(5) Other examples: (a) Fu¨rstner, A.; Krause, H. AdV. Synth. Catal. 2001,
343, 343-350. (b) Moreau, C.; Hague, C.; Weller, A. S.; Frost, C. G.
Tetrahedron Lett. 2001, 42, 6957-6960. (c) Bolm, C.; Rudolph, J. J. Am.
Chem. Soc. 2002, 124, 14850-14851. (d) Son, S. U.; Kim, S. B.; Reingold,
J. A.; Carpenter, G. B.; Sweigart, D. A. J. Am. Chem. Soc. 2005, 127,
12238-12239. (e) Focken, T.; Rudolph, J.; Bolm, C. Synthesis 2005, 429-
436. (f) Duan, H.-F.; Xie, J.-H.; Shi, W.-J.; Zhang, Q.; Zhou, Q.-L. Org.
Lett. 2006, 8, 1479-1481. (g) Suzuki, K.; Ishii, S.; Kondo, K.; Aoyama,
T. Synlett 2006, 648-650. (h) Suzuki, K.; Kondo, K.; Aoyama, T. Synthesis
2006, 1360-1364. (i) Jagt, R. B. C.; Toullec, P. Y.; de Vries, J. G.; Feringa,
B. L.; Minnaard, A. J. Org. Biomol. Chem. 2006, 4, 773-775. (j) Gois, P.
M. P.; Trindade, A. F.; Veiros, L. F.; Andre´, V.; Duarte, M. T.; Afonso, C.
A. M.; Caddick, S.; Cloke, F. G. N. Angew. Chem., Int. Ed. 2007, 46, 5750-
5753.
Recently, Gibson and Cole-Hamilton found phosphapallada-
cyclic complex-catalyzed 1,2-addition of phenylboronic acid to
4-chlorobenzaldehyde as a side reaction.6 On the basis of this
finding, Ohta developed addition reactions of arylboronic acids
to aromatic aldehydes catalyzed by palladium-triphenylphos-
(1) Beller, M.; Bolm, C. Transition Metals for Organic Synthesis:
Building Blocks and Fine Chemicals; Wiley-VCH: New York, 1998.
(2) (a) Suzuki, A. Acc. Chem. Res. 1982, 15, 178-184. (b) Miyaura,
N.; Suzuki, A. Chem. ReV. 1995, 95, 2457-2483. (c) Suzuki, A. J.
Organomet. Chem. 1998, 576, 147-168.
(3) (a) Sakai, M.; Ueda, M.; Miyaura, N. Angew. Chem., Int. Ed. 1998,
37, 3279-3281. (b) Ueda, M.; Miyaura, N. J. Org. Chem. 2000, 65, 4450-
4452.
(6) Gibson, S.; Foster, D. F.; Eastham, G. R.; Tooze, R. P.; Cole-
Hamilton, D. J. Chem, Commun. 2001, 779-780.
(7) Yamamoto, T.; Ohta, T.; Ito, Y. Org. Lett. 2005, 7, 4153-4155.
(8) Suzuki, K.; Arao, T.; Ishii, S.; Maeda, Y.; Kondo, K.; Aoyama, T.
Tetrahedron Lett. 2006, 47, 5789-5792.
(4) (a) Casy, A. F.; Drake, A. F.; Ganellin, C. R.; Mercer, A. D.; Upton,
C. Chirality 1992, 4, 356-366. (b) Spencer, C. M.; Foulds, D.; Peter, D.
H. Drugs 1993, 46, 1055-1080. (c) Botta, M.; Summa, V.; Corelli, F.;
Pietro, G. D.; Lombardi, P. Tetrahedron: Asymmetry 1996, 7, 1263-1266.
(9) (a) He, P.; Lu, Y.; Dong, C.-G.; Hu, Q.-S. Org. Lett. 2007, 9, 343-
346. (b) He, P.; Lu, Y.; Hu, Q.-S. Tetrahedron Lett. 2007, 48, 5283-5288.
(10) Qin, C.; Wu, H.; Cheng, J.; Chen, X.; Liu, M.; Zhang, W.; Su, W.;
Ding, J. J. Org. Chem. 2007, 72, 4102-4107.
10.1021/jo7020983 CCC: $40.75 © 2008 American Chemical Society
Published on Web 01/11/2008
J. Org. Chem. 2008, 73, 1597-1600
1597

TABLE 1. Palladium-Catalyzed 1,2-Addition of Phenylboronic
Acid to Benzaldehyde under Various Reaction Conditionsa
TABLE 2. Palladium-Catalyzed 1,2-Addition of Aryl-, Heteroaryl-,
and Alkenylboronic Acids to 2-Naphthaldehyde Using
Thioether-Imidazolinium Chloridea
entry
ligand
L1
L2
L3
L4
L5
L6
SIPr‚HCl
L5
L5
L5
L5
L5
L5
L5
base
solvent
yield (%)b
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18c
19d
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
K2CO3
Na2CO3
K3PO4
CsF
CsF
CsF
CsF
CsF
CsF
CsF
CsF
CsF
toluene
toluene
toluene
toluene
toluene
toluene
toluene
toluene
toluene
toluene
toluene
dioxane
DMA
12
40
20
82
95
85
8
74
17
71
97
99
39
37
36
0
DMF
L5
DMSO
dioxane
dioxane
dioxane
dioxane
PhSMe
none
L5
0
99
54
L5
a Reaction conditions: benzaldehyde (1.0 mmol), phenylboronic acid (1.5
mmol), ligand (1 mol %), [Pd(allyl)Cl]2 (0.5 mol %), base (2.0 mmol),
solvent (2 mL), 80 °C, 20 min. b Isolated yield. c The reaction using 0.05
mol % of L5 and 0.025 mol % of [Pd(allyl)Cl]2 was carried out for 12 h.
d The reaction using 0.005 mol % of L5 and 0.0025 mol % of [Pd(allyl)Cl]2
was carried out for 24 h.
was most suitable, affording the adduct 3aa in 99% yield. Highly
polar solvents such as DMA, DMF, and DMSO led to low yields
(entries 11-15). It was suggested that active thioether-
imidazolinium carbene-palladium species were formed in situ
under basic conditions because the control experiment with
thioanisole or no imidazolinium chloride gave no conversion
(entries 16 and 17). The low catalyst loading conditions were
conducted, and the addition reactions using 0.05 and 0.005 mol
% of the catalyst under the optimized condition led to 99% and
54% yield, respectively (entries 18 and 19).
a Reaction conditions: 2-naphthaldehyde (1.0 mmol), boronic acid (1.5
mmol), L5/Pd ) 1/1, CsF (2.0 mmol), dioxane (2 mL), 80 °C. b Isolated
yield. c The reaction was carried out at 100 °C. d 2.5 equiv of boronic acid
was used. e Water (0.2 mL) was added to dissolve precipitate.
The influence of varying aryl- and alkenylboronic acids in
the addition reactions with 0.5-2.0 mol % of the catalyst using
2-naphthaldehyde 1b was investigated (Table 2). The reaction
using sterically hindered 2-biphenylboronic acid 2b gave the
adduct 3bb with 98% yield (entry 1). Both the electron-rich
and -poor arylboronic acids substituted at the 2-position (2c and
2d) were converted efficiently (entries 2 and 3). The sterically
hindered 2,6-dimethoxyphenylboronic acid 2e reacted to afford
95% yield (entry 4), although the palladium-catalyzed arylation
with 2,6-disubstituted arylboronic acid was known as a difficult
task.10 The alkenylboronic acids 2f-h also gave the adducts
3bf-3bh with high yields (entries 5-7). Then, heteroaryl
boronic acids containing nitrogen, oxygen, and sulfur atoms
were examined. While the reaction with 1-methyl-5-indolebo-
ronic acid 2i proceeded smoothly, N-protected 3-indoleboronic
acid 2j was less reactive leading to 75% yield (entries 8 and
9). To obtain the adduct 3bk with 82% yield, 2.5 equiv of
3-furanboronic acid 2k was needed (entry 10). 2-Furanboronic
acid 2l and 3-thiophenboronic acid 2m afforded excellent results
(entries 11 and 12).
Investigation of aldehydes in the addition reactions of
arylboronic acids using 0.5-1.5 mol % of the palladium/
thioether-imidazolinium chloride system was also conducted
(Table 3). Both the electron-rich and -poor aromatic aldehydes
(1c and 1d) were easily converted (entries 1 and 2). 2-Meth-
oxybenzaldehyde 1e reacted with the ortho-substituted phenyl-
boronic acid 2c, efficiently (entry 3). Moreover, the addition to
electron-rich and sterically hindered 2,6-dimethoxybenzaldehyde
1f with phenylboronic acid 2a led to 98% yield (entry 4),
although it was reported that the addition to this class of aromatic
aldehyde was sluggish.10 The addition reaction of 2c to 1f gave
the product 3fc with the acceptable yield (entry 5). Phenyl
groups were introduced to the aliphatic aldehydes 1g-i,
affording the adducts 3ga-3ia with good yields (entries 6-8).
The heteroaromatic aldehydes 1j-m, which have not been
examined in previous reports,6-10 were also good acceptors,
(11) Kuriyama, M.; Shimazawa, R.; Shirai, R. Tetrahedron 2007, 63,
9393-9400.
(12) Hemilabile behavior of thioether-functionalized NHC was investi-
gated: Huynh, H. V.; Yeo, C. H.; Tan, G. K. Chem. Commun. 2006, 3833-
3835.
1598 J. Org. Chem., Vol. 73, No. 4, 2008

TABLE 3. Palladium-Catalyzed 1,2-Addition of Arylboronic Acids
to Aromatic, Heteroaromatic, and Aliphatic Aldehydes Using
Thioether-Imidazolinium Chloridea
NH4Cl were added, and then it was extracted with CH2Cl2. The
combined organic layers were washed with brine, and then dried
over MgSO4. Concentration and purification through silica gel
column chromatography gave the product 3bb.
2-Biphenyl-2-naphthylmethanol (3bb). Silica gel column chro-
matography (hexane/AcOEt ) 10/1) gave 305 mg (0.98 mmol, 98%
1
yield) of the product as colorless viscous oil. H NMR (CDCl3) δ
2.20 (1H, d, J ) 4.0 Hz), 6.10 (1H, d, J ) 4.0 Hz), 7.24-7.40
(9H, m), 7.43-7.47 (2H, m), 7.58 (1H, dd, J ) 1.0, 7.5 Hz), 7.64
(1H, s), 7.72 (1H, d, J ) 8.5 Hz), 7.74-7.79 (2H, m). 13C NMR
(CDCl3) δ 72.4, 124.9, 125.0, 125.8, 126.0, 127.2, 127.3, 127.5,
127.5, 127.9, 128.0, 128.1, 129.3, 130.0, 132.6, 133.1, 140.75,
140.81, 141.2, 141.4. IR (neat) 3370 cm-1. HRMS (EI) calcd for
C23H18O (M+) 310.1358, found 310.1362.
2,6-Dimethoxyphenyl-2-naphthylmethanol (3be). Silica gel
column chromatography (hexane/AcOEt ) 5/1) gave 279 mg (0.95
mmol, 95% yield) of the product as a pale yellow solid of mp 140-
1
141 °C. H NMR (CDCl3) δ 3.79 (6H, s), 4.45 (1H, d, J ) 12.0
Hz), 6.48 (1H, d, J ) 12.0 Hz), 6.62 (2H, d, J ) 8.5 Hz), 7.25
(1H, t, J ) 8.5 Hz), 7.39-7.44 (2H, m), 7.49 (1H, dd, J ) 1.5, 8.5
Hz), 7.74 (1H, d, J ) 8.5 Hz), 7.77-7.79 (3H, m). 13C NMR
(CDCl3) δ 55.8, 68.6, 104.6, 119.4, 123.6, 124.7, 125.3, 125.7,
127.5, 128.0, 129.0, 132.4, 133.2, 142.2, 157.8. IR (nujol) 1260,
3550 cm-1. EIMS m/z 294 (M+). Anal. Calcd for C19H18O3: C,
77.53; H, 6.16. Found: C, 77.30; H, 6.12.
(E)-1-Octenyl-2-naphthylmethanol (3bg). Silica gel column
chromatography (hexane/AcOEt ) 10/1) gave 215 mg (0.80 mmol,
1
80% yield) of the product as pale yellow oil. H NMR (CDCl3) δ
0.87 (3H, t, J ) 7.0 Hz), 1.24-1.33 (6H, m), 1.37-1.42 (2H, m),
1.94 (1H, d, J ) 3.5 Hz), 2.07 (2H, q, J ) 7.0 Hz), 5.34 (1H, dd,
J ) 3.5, 6.5 Hz), 5.73 (1H, dd, J ) 6.5, 15.0 Hz), 5.82 (1H, dt, J
) 7.0, 15.0 Hz), 7.44-7.49 (3H, m), 7.82-7.84 (4H, m). 13C NMR
(CDCl3) δ 14.1, 22.6, 28.9, 29.0, 31.7, 32.2, 75.3, 124.5, 125.8,
126.1, 127.6, 128.0, 128.2, 132.1, 132.9, 133.2, 133.3, 140.8. IR
(neat) 3350 cm-1. EIMS m/z 268 (M+). Anal. Calcd for C19H24O:
C, 85.03; H, 9.01. Found: C, 85.13; H, 9.26.
1-(1,2-Dimethyl)propenyl-2-naphthylmethanol (3bh). Silica
gel column chromatography (hexane/AcOEt ) 10/1) gave 210 mg
(0.93 mmol, 93% yield) of the product (3bh) as a pale yellow solid
1
of mp 87-88 °C. H NMR (CDCl3) δ 1.51 (3H, s), 1.77 (3H, s),
1.83 (1H, d, J ) 3.5 Hz), 1.97 (3H, d, J ) 1.5 Hz), 6.02 (1H, d,
J ) 3.5 Hz), 7.36 (1H, dd, J ) 1.5, 8.5 Hz), 7.43-7.49 (2H, m),
7.78 (1H, d, J ) 8.5 Hz), 7.82 (1H, d, J ) 8.5 Hz), 7.84 (1H, d,
J ) 8.5 Hz), 7.88 (1H, s). 13C NMR (CDCl3) δ 12.3, 20.3, 21.2,
72.3, 123.7, 124.2, 125.5, 125.9, 127.6, 127.7, 128.0, 129.0, 129.3,
132.5, 133.3, 140.7. IR (nujol) 3320 cm-1. EIMS m/z 226 (M+).
Anal. Calcd for C16H18O: C, 84.91; H, 8.02. Found: C, 84.72; H,
8.27.
a Reaction conditions: aldehyde (1.0 mmol), boronic acid (1.5 mmol),
L5/Pd ) 1/1, CsF (2.0 mmol), dioxane (2 mL), 80 °C, 3 h. b Isolated yield.
c The reaction was carried out at 100 °C.
being converted to the addition products 3ja-3ma with
excellent yields (entries 9-12).
(1-Methyl-5-indolyl)-2-naphthylmethanol (3bi). Silica gel col-
umn chromatography (hexane/AcOEt ) 10/1) gave 283 mg (0.99
mmol, 99% yield) of the product as a pale yellow solid of mp 92-
93 °C. 1H NMR (CDCl3) δ 2.29 (1H, d, J ) 3.5 Hz), 3.77 (3H, s),
6.13 (1H, d, J ) 1.5 Hz), 6.46 (1H, d, J) 3.5 Hz), 7.05 (1H, d, J
) 3.5 Hz), 7.24 (1H, dd, J ) 1.5, 8.5 Hz), 7.28 (1H, d, J ) 8.5
Hz), 7.43-7.48 (3H, m), 7.67 (1H, s), 7.76 (1H, d, J ) 8.5 Hz),
7.79-7.85 (2H, m), 7.97 (1H, s). 13C NMR (CDCl3) δ 32.8, 76.8,
101.2, 109.4, 119.4, 120.9, 124.6, 125.0, 125.7, 126.0, 127.6, 128.0,
128.1, 128.3, 129.4, 132.7, 133.3, 135.0, 136.3, 141.9. IR (nujol)
3440 cm-1. EIMS m/z 287 (M+). Anal. Calcd for C20H17NO: C,
83.59; H, 5.96; N, 4.87. Found: C, 83.30; H, 5.89; N, 4.78.
(1-Phenylsulfonyl-3-indolyl)-2-naphthylmethanol (3bj). Silica
gel column chromatography (hexane/AcOEt ) 3/1) gave 311 mg
(0.75 mmol, 75% yield) of the product as a pale orange amorphous.
1H NMR (CDCl3) δ 2.30 (1H, d, J ) 4.0 Hz), 6.19 (1H, d, J ) 4.0
Hz), 7.11-7.14 (1H, m), 7.27-7.30 (1H, m), 7.41-7.47 (4H, m),
7.48-7.51 (3H, m), 7.55 (1H, t, J ) 7.5 Hz), 7.81-7.84 (3H, m),
7.87-7.89 (2H, m), 7.91 (1H, s), 7.98 (1H, d, J ) 8.5 Hz). 13C
NMR (CDCl3) δ 70.4, 113.7, 120.6, 123.3, 123.9, 124.6, 124.9,
In conclusion, we found that 1,2-addition of aryl-, heteroaryl-,
and alkenylboronic acids to aromatic, heteroaromatic, and
aliphatic aldehydes was catalyzed by 0.005-2.0 mol % of the
palladium/thioether-imidazolinium chloride system quite ef-
ficiently. Further efforts are focused on mechanistic investigation
and development of an asymmetric version in our laboratory.
Experimental Section
Typical Procedure of 1,2-Addition Reaction Catalyzed by the
Palladium/Thioether-Imidazolinium Chloride System. Under
argon atmosphere, a reaction tube was charged with [Pd(allyl)Cl]2
(0.92 mg, 0.0025mmol), imidazolinium chloride L5 (2.26 mg, 0.005
mmol), and cesium fluoride (304 mg, 2.0 mmol), and then dioxane
(2.0 mL) was added. The mixture was stirred for 15 min at 80 °C
and cooled to room temperature. Then, 2-naphthaldehyde 1b (156
mg, 1.0 mmol) and 2-biphenylboronic acid 2b (297 mg, 1.5 mmol)
were added, and the reaction mixture was stirred at 80 °C for 3 h.
The mixture was cooled to room temperature, and water and satd
J. Org. Chem, Vol. 73, No. 4, 2008 1599

125.5, 125.6, 126.2, 126.3, 126.7, 127.7, 128.1, 128.5, 128.9, 129.2,
133.1, 133.2, 133.8, 135.6, 138.0, 139.3. IR (KBr) 1170, 3410 cm-1
7.51 (3 H, m), 7.82-7.85 (3H, m), 7.89 (1H, s). 13C NMR (CDCl3)
δ 72.9, 121.8, 124.6, 125.0, 126.0, 126.2, 126.3, 126.4, 127.7, 128.1,
.
HRMS (EI) calcd for C25H19NO3S (M+) 413.1086, found 413.1084.
3-Furanyl-2-naphthylmethanol (3bk). Silica gel column chro-
matography (hexane/AcOEt ) 5/1) gave 184 mg (0.82 mmol, 82%
yield) of the product as yellow oil. 1H NMR (CDCl3) δ 2.21 (1H,
d, J ) 4.0 H), 5.96 (1H, d, J ) 4.0 Hz), 6.36 (1H, d, J ) 1.0 Hz),
7.36 (1H, d, J ) 1.0 Hz), 7.39 (1H, t, J ) 1.5 Hz), 7.48-7.51 (3H,
m), 7.83-7.85 (3H, m), 7.90 (1H, s). 13C NMR (CDCl3) δ 69.6,
109.2, 124.5, 124.9, 126.0, 126.2, 127.7, 128.0, 128.3, 128.8, 133.0,
128.3, 133.0, 133.2, 140.7, 145.2. IR (neat) 1420, 1510, 3360 cm-1
.
HRMS (EI) calcd for C15H12OS (M+) 240.0609, found 240.0608.
2,6-Dimethoxyphenyl(2-methoxyphenyl)methanol (3fc). Silica
gel column chromatography (benzene/AcOEt ) 20/1) gave 177 mg
(0.65 mmol, 65% yield) of the product as a colorless solid of mp
131-132 °C. 1H NMR (CDCl3) δ 3.80 (6H, s), 3.87 (3H, s), 4.33
(1H, d, J ) 11.0 Hz), 6.60 (1H, d, J ) 11.0 Hz), 6.61 (2H, d, J )
8.0 Hz), 6.83 (1H, dt, J ) 1.0, 8.0 Hz), 6.89 (1H, d, J ) 8.0 Hz),
7.10 (1H, dd, J ) 1.5, 8.0 Hz), 7.20-7.25 (2H, m). 13C NMR
(CDCl3) δ 55.67, 55.75, 64.8, 104.5, 110.8, 118.3, 119.8, 127.6,
128.3, 128.6, 131.5, 157.6, 158.1. IR (nujol) 3570 cm-1. EIMS
m/z 274 (M+). Anal. Calcd for C16H18O4: C, 70.06; H, 6.61.
Found: C, 70.18; H, 6.63.
133.2, 139.9, 140.3, 143.5. IR (neat): 1510, 1600, 3370 cm-1
.
HRMS (EI) Calcd for C15H12O2 (M+) 224.0837, found 224.0838.
2-Furanyl-2-naphthylmethanol (3bl). Silica gel column chro-
matography (hexane/AcOEt ) 10/1) gave 209 mg (0.93 mmol, 93%
1
yield) of the product as pale yellow oil. H NMR (CDCl3) δ 2.47
(1H, d, J ) 4.5 Hz), 6.01 (1H, d, J ) 4.5 Hz), 6.15 (1H, d, J ) 3.0
Hz), 6.33 (1H, dd, J ) 2.0, 3.0 Hz), 7.41 (1H, d, J ) 1.0 Hz),
7.47-7.51 (2H, m), 7.53 (1H, dd, J ) 1.5, 8.5 Hz), 7.83-7.85
(3H, m), 7.93 (1H, s). 13C NMR (CDCl3) δ 70.2, 107.6, 110.3,
124.6, 125.3, 126.1, 126.2, 127.7, 128.1, 128.2, 133.1, 133.2, 138.1,
142.6, 155.8. IR (neat) 1500, 1600, 3370 cm-1. HRMS (EI) calcd
for C15H12O2 (M+) 224.0837, found 224.0841.
3-Thienyl-2-naphthylmethanol (3bm). Silica gel column chro-
matography (hexane/AcOEt ) 5/1) gave 237 mg (0.99 mmol, 99%
yield) of the product as yellow oil. 1H NMR (CDCl3) δ 2.32 (1H,
d, J ) 4.0 Hz), 6.07 (1H, d, J ) 4.0 Hz), 7.03 (1H, dd, J ) 1.0,
4.0 Hz), 7.23-7.24 (1H, m), 7.28 (1H, dd, J ) 3.0, 5.0 Hz), 7.46-
Acknowledgment. This work was supported by Grant-in-
Aid for Scientific Research (C) (No. 18590023) from the Japan
Society for the Promotion of Science.
Supporting Information Available: General procedure of 1,2-
addition catalyzed by the palladium/thioether-imidazolinium chlo-
1
ride system, spectral data of products, and copies of H and 13C
NMR spectra of products. This material is available free of charge
via the Internet at http://pubs.acs.org.
JO7020983
1600 J. Org. Chem., Vol. 73, No. 4, 2008