Synthesis of 2-acyl-1-naphthols by gold-catalyzed oxidative cyclization of 2-alkenylphenyl alkynyl ketones

Article abstract of DOI:10.1016/j.tet.2014.12.041

The gold(I)-catalyzed oxidative cyclization of 2-alkenylphenyl alkynyl ketones employing organic oxides as oxidants has been developed. This reaction involves aromatization to furnish 2-acyl-1-naphthols. Also, 10-acyl-9-phenanthrenols are analogously prod

Full text of DOI:10.1016/j.tet.2014.12.041

Tetrahedron 71 (2015) 869e874
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Synthesis of 2-acyl-1-naphthols by gold-catalyzed oxidative
cyclization of 2-alkenylphenyl alkynyl ketones
*
Takanori Matsuda , Yahiro Nishida, Kentaro Yamanaka, Yusuke Sakurai
Department of Applied Chemistry, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 7 October 2014
Received in revised form 11 December 2014
Accepted 12 December 2014
Available online 18 December 2014
The gold(I)-catalyzed oxidative cyclization of 2-alkenylphenyl alkynyl ketones employing organic oxides
as oxidants has been developed. This reaction involves aromatization to furnish 2-acyl-1-naphthols. Also,
10-acyl-9-phenanthrenols are analogously produced from the reaction of alkynyl 2-biphenyl ketones.
Ó 2014 Elsevier Ltd. All rights reserved.
Keywords:
Enynes
Gold
Cyclization
Aromatization
Naphthols
1. Introduction
Being
a valuable method for the synthesis of variously
substituted aromatic compounds, gold-catalyzed benzannulation
reactions have been extensively studied.1,2 Liu et al. reported oxi-
dative cyclization of 2-alkenylphenyl alkynyl carbinols with H2O2
under the catalysis of Pt(II) or Au(I) complexes to afford 2-naphthyl
aldehydes and ketones (Scheme 1a).1g However, the reaction of the
corresponding ketones, i.e., 2-alkenylphenyl alkynyl ketones, is yet
to be studied. In this paper, we report oxidative cyclization of keto-
enynes with N-oxides or a sulfoxide in the presence of gold(I)
catalysts (Scheme 1b).3,4 The reaction proceeded efficiently at rt,
resulting in benzannulation to afford a variety of 2-acyl-1-naphthol
derivatives. This was subsequently applied for the synthesis of
10-acyl-9-phenanthrenols by reacting alkynyl 2-biphenyl ketones
at 120 ꢀC under gold catalysis.
Scheme 1. Catalyzed oxidative cyclization of 2-alkenylphenyl alkynyl carbinols and
ketones.
quinoline N-oxide (QO) and 1.5 equiv of camphorsulfonic acid
(CSA), oxidative cyclization of 1 with QO occurred, resulting in the
isolation of 2-acetyl-4-phenyl-1-naphthol (2a) in 35% yield (Table 1,
entry 1). The use of pyridine N-oxide (PO) as the oxidant improved
the yield of 2a to 75% (entry 2).5 The efficiency of the reaction
deteriorated significantly in the absence of CSA (entry 3).6 We
found that diphenyl sulfoxide (Ph2SO) could also be employed as an
alternative oxidant for the oxidative cyclization and is preferable
for operation because the acid additive is not required (entry 4).
After screening the phosphine ligands of the gold(I) complexes, (t-
BuXPhos)AuNTf2 was determined to be the optimal catalyst for this
reaction (entries 5 and 6).
2. Results and discussion
When 2-(1-phenylvinyl)phenyl prop-1-yn-1-yl ketone (1a)
was reacted at 0 ꢀC for 30 min, and then at rt in 1,2-dichloroethane
(DCE) in the presence of 2 mol % gold(I) catalyst, (JohnPhos)AuNTf2,
a complex mixture of products was obtained. On the other hand,
when the reaction was performed in the presence of 2.5 equiv of
* Corresponding author. Tel.: þ81 3 5228 8258; fax: þ81 3 5261 4631; e-mail
address: mtd@rs.tus.ac.jp (T. Matsuda).
http://dx.doi.org/10.1016/j.tet.2014.12.041
0040-4020/Ó 2014 Elsevier Ltd. All rights reserved.

870
T. Matsuda et al. / Tetrahedron 71 (2015) 869e874
Table 1
Table 2
Selected optimization experiments for gold(I)-catalyzed oxidative cyclization of 1a
Synthesis of 2-acyl-1-naphthols 2 by gold(I)-catalyzed oxidative cyclization of 1
with oxidesa
with Ph2SOa
Entry
Enyne 1 (R, R0)
Product 2
Yieldb (%)
1
2
3
4
5
6
7
1b (4-MeOC6H4, Me)
1c (4-ClC6H4, Me)
1d (Ph, Pr)
1e (Me, Me)
1f (Me, H)
2b
2c
2d
2e
2f
75
79
63
74
72
78
21
1g (Ph, H)
1h (Ph, Ph)
2g
2h
ZþeOꢁ
Additive
Yieldb (%)
a
Entry
Au catalyst
Enyne
1 (0.100 mmol) and Ph2SO (0.250 mmol) were reacted in 1,2-
dichloroethane (1.0 mL) at rt in the presence of (t-BuXPhos)AuNTf2 (2.0
m
mol).
1
2
3
4
5
6
(JohnPhos)AuNTf2
(JohnPhos)AuNTf2
(JohnPhos)AuNTf2
(JohnPhos)AuNTf2
(XPhos)AuNTf2
QO
PO
PO
Ph2SO
Ph2SO
Ph2SO
CSA
CSA
None
None
None
None
35
75
19
75
79
84
b
Isolated yield.
(t-BuXPhos)AuNTf2
the internal olefinic carbons, afforded 4-aryl 2-acetyl-1-naphthols
2b and 2c, respectively, in good yields (entries 1 and 2). Pent-1-
yn-1-yl ketone 1d and 2-isopropenylphenyl ketone 1e also gave
the corresponding products 2d and 2e (entries 3 and 4). Further-
more, ethynyl ketones (1f and 1g) were converted into 2-formyl-1-
naphthols (2f and 2g) (entries 5 and 6). However, as evident by the
low yield, 1h (R¼R0¼Ph) was largely averse to oxidative cyclization
(entry 7).7
Substrates possessing substituents on the o-phenylene tether
and heteroarene-tethered enynes were also examined (Table 3).
Fluoro- and methylenedioxy-substituted naphthols 2i and 2j
were synthesized in 52% and 61% yields, respectively, and phe-
nanthrenol 2k was also obtained analogously from the 1,2-
naphthylene derivative 1k (entries 1e3). The gold-catalyzed
cyclization was applicable to thienylene-tethered enyne 1l,
which provided access to trisubstituted benzo[b]thiophene 2l,
albeit with diminished yields (entry 4).8 The reaction of the
pyridylene derivative 1m produced trisubstituted quinoline 2m
in only 18% yield, even when the reaction was performed at
120 ꢀC (entry 5).8
a
Enyne 1a (0.100 mmol) was reacted in the presence of oxide (0.250 mmol),
additive (0.150 mmol), Au catalyst (2.0
for 30 min, and then at rt for 12 h.
m C
mol) in 1,2-dichloroethane (1.0 mL) at 0 ꢀ
b
Isolated yield.
Two mechanistic scenarios explain the gold-catalyzed oxidative
cyclization reaction of enyne 1a to produce naphthol 2a (Scheme 2).
The first scenario (path a) involves initial cyclization of 1a by Au(I)
in a 6-exo-dig fashion. The resulting six-membered intermediate A
aromatizes to generate carbene gold B, which is subsequently
intercepted by the oxide (ZþeOꢁ) to furnish 2a via C. Alternatively,
the alkyne moiety of 1a initially reacts with Au(I) and N-oxide to
give
a,
a
0-dioxo carbene gold E, which subsequently reacts with the
(path b). Finally, proto-
pendant alkene moiety to give
demetalation, followed by aromatization, leads to 2a.
F
In cases where an enyne lacked the substituent at the internal
olefinic carbon, aromatization producing naphthalene was not
observed. Instead, cyclopropanation occurred generating diketone
3 in a 46% yield (Scheme 3).9 The results may suggest that the cy-
clization likely proceeds via path b rather than path a.
Our attention was subsequently drawn to the reaction of alkynyl
2-biphenyl ketones 1oeq with an expectation that the aryl group
can participate in the benzannulation reaction as an alkene surro-
gate. The reaction failed to proceed at rt; however, it occurred at
120 ꢀC in p-xylene, giving rise to the formation of 10-acyl-9-
phenanthrenols 2oeq (Scheme 4).10 Yields of the reaction were in
the range of 16e57%; the highest yield was achieved when the
phenylethynyl derivative 1q reacted with PO.
Interestingly, naphthol 2a was also prepared by gold(I)-
catalyzed reaction of the isomeric alkynyl ketone 4 (Scheme 5).
This reaction employing PO as the oxidant gave 2a in a 57% yield. In
sharp contrast, the use of Ph2SO did not result in oxidation, instead
leading to the exclusive formation of alkylideneindene 5 through
intramolecular hydroalkenylation.1x
The reaction of substrates possessing alcohol oxidation levels
under our conditions was also investigated (Scheme 6). Both 6a
(R¼H) and 6b (R¼Me) underwent the gold(I)-catalyzed oxidative
cyclization with Ph2SO at 40 ꢀC to afford 2-acetylnaphthalenes 7a
and 7b in 42% and 37% yields, respectively, by way of
dehydration.
Scheme 2. Two possible reaction pathways.
Various keto-enynes 1 were then subjected to a reaction with
Ph2SO in the presence of (t-BuXPhos)AuNTf2 (Table 2). Enynes 1b
and 1c, possessing 4-methoxyphenyl and 4-chlorophenyl groups at

T. Matsuda et al. / Tetrahedron 71 (2015) 869e874
871
Table 3
Gold(I)-catalyzed reaction of enynes 1iem with Ph2SOa
Entry
Enyne 1
Product 2
Yieldb (%)
Scheme 4. Reaction of alkynyl 2-biphenyl ketones 1oeq.
1
52
2i
1i
1j
2
3
4
61
89
33
2j
Scheme 5. Gold(I)-catalyzed reaction of methyl [2-(1-phenylvinyl)phenyl]ethynyl
ketone (4).
Scheme 6. Reaction of (1-phenylvinyl)phenyl prop-1-yn-1-yl carbinols 6a and 6b.
1l
2l
4. Experimental section
4.1. General
5c
18
All reactions were carried out with standard Schlenk techniques
under a nitrogen atmosphere. Column chromatography was per-
formed on WakogelÒ C-200 (75e150
mm). Preparative thin-layer
chromatography was performed on WakogelÒ B-5F. Proton chem-
ical shifts were referenced to residual CHCl3 signal at 7.26 ppm.
Carbon chemical shifts were referenced to CDCl3 at 77.0 ppm.
Melting points were not corrected.
1m
a
Enyne
1 (0.100 mmol) and Ph2SO (0.250 mmol) were reacted in 1,2-
dichloroethane (1.0 mL) at rt in the presence of (t-BuXPhos)AuNTf2 (2.0
m
mol).
b
Isolated yield.
The reaction was performed at 120 ꢀC in p-xylene.
c
4.2. General procedure for gold(I)-catalyzed cyclization
A Schlenk tube was charged with substrate (0.100 mmol), (t-
BuXPhos)AuNTf2 (2.0 mmol, 2 mol %), organic oxidant (0.250 mmol),
and camphorsulfonic acid (0.150 mmol) (liquid substrates were
added via syringe after 1,2-dichloroethane). The tube was evacu-
ated and backfilled with argon. 1,2-Dichloroethane (or p-xylene,
1.0 mL) was added via a syringe through the septum. The mixture
was stirred at 0 ꢀC for 30 min, and then at the indicated tempera-
ture for the indicated time. The reaction mixture was filtered
through a plug of FlorisilÒ washing with hexane/AcOEt (1:1), and
the filtrate was concentrated. The residue was purified by pre-
parative TLC on silica gel to afford the following compounds.
Scheme 3. Reaction of prop-1-yn-1-yl 2-vinylphenyl ketone (1n).
3. Conclusion
In summary, we developed a gold-catalyzed cyclization of 2-
alkenylphenyl alkynyl ketones using N-oxides or Ph2SO as oxi-
dants. The reaction resulted in aromatization to afford 2-acyl-1-
naphthols. The oxidative cyclization can be applied to alkynyl 2-
biphenyl ketones, thereby enabling the synthesis of 10-acyl-9-
phenanthrenols.
4.2.1. 2-Acetyl-4-phenyl-1-naphthol (2a). According to the general
procedure, 1a (24.6 mg, 0.100 mmol), (t-BuXPhos)AuNTf2 (1.8 mg,

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T. Matsuda et al. / Tetrahedron 71 (2015) 869e874
2.0
mmol), and Ph2SO (50.6 mg, 0.250 mmol) were reacted in 1,2-
2.2 mmol), and Ph2SO (51.4 mg, 0.254 mmol) were reacted in 1,2-
dichloroethane (1.0 mL): rt for 12 h. Purification by preparative TLC
on silica gel (hexane/AcOEt¼10:1) afforded 2a (21.9 mg, 0.083 mmol,
84%) as a yellow solid. Compound 2a was obtained in 57% yield
(14.5 mg, 0.055 mmol) from 4 (23.7 mg, 0.096 mmol), pyridine N-
oxide (24.5 mg, 0.258 mmol), and camphorsulfonic acid (35.2 mg,
0.152 mmol). Mp 178e181 ꢀC (lit. 182e183 ꢀC;11a 178e180 ꢀC11b); 1H
dichloroethane (1.0 mL): rt for 25 h. Purification by preparative
TLC on silica gel (hexane/AcOEt¼10:1) afforded 2f (13.8 mg,
0.074 mmol, 72%) as a pale yellow solid. Mp 68e69 ꢀC; 1H NMR
(CDCl3, 500 MHz)
7.72 (t, J¼7.8 Hz, 1H), 7.92 (d, J¼8.0 Hz, 1H), 8.48 (d, J¼8.5 Hz, 1H),
9.93 (s, 1H), 12.5 (s, 1H); 13C NMR (CDCl3, 126 MHz)
18.7, 113.8,
d
2.60 (s, 3H), 7.29 (s, 1H), 7.57 (t, J¼7.5 Hz, 1H),
d
NMR (CDCl3, 500 MHz)
d
2.71 (s, 3H), 7.42e7.62 (m, 8H), 7.80 (d,
124.2, 124.6, 124.8, 125.4, 125.8, 125.9, 130.5, 136.8, 160.6, 196.3;
J¼8.0 Hz, 1H), 8.56 (d, J¼7.5 Hz, 1H), 14.01 (s, 1H). The spectral data
HRMS (ESI) calcd for
C
12H10NaO2 [MþNa]þ 209.0573, found
matched those reported in the literature.11
209.0571; IR (n
/cmꢁ1): 3420, 1597, 1448, 755.
4.2.2. 2-Acetyl-4-(4-methoxyphenyl)-1-naphthol (2b). According to
the general procedure, 1b (27.9 mg, 0.101 mmol), (t-BuXPhos)
4.2.7. 2-Formyl-4-phenyl-1-naphthol (2g). According to the general
procedure, 1g (24.1 mg, 0.104 mmol), (t-BuXPhos)AuNTf2 (1.9 mg,
AuNTf2 (1.7 mg, 1.9
mmol), and Ph2SO (50.2 mg, 0.248 mmol) were
2.1 mmol), and Ph2SO (51.0 mg, 0.252 mmol) were reacted in 1,2-
reacted in 1,2-dichloroethane (1.0 mL): rt for 12 h. Purification by
preparative TLC on silica gel (hexane/AcOEt¼8:1, two times)
afforded 2b (22.1 mg, 0.076 mmol, 75%) as a pale yellow solid. Mp
dichloroethane (1.0 mL): rt for 12 h. Purification by preparative
TLC on silica gel (hexane/AcOEt¼10:1) afforded 2g (20.2 mg,
0.081 mmol, 78%) as a yellow solid. Mp 121e123 ꢀC; 1H NMR
140e141 ꢀC; 1H NMR (CDCl3, 500 MHz)
d
2.70 (s, 3H), 3.91 (s, 3H),
(CDCl3, 500 MHz) d 7.40e7.52 (m, 6H), 7.52e7.58 (m, 2H), 7.85 (d,
7.02e7.07 (m, 2H), 7.37e7.41 (m, 2H), 7.62e7.71 (m, 3H), 7.80 (d,
J¼8.0 Hz, 1H), 8.54 (d, J¼9.0 Hz, 1H), 9.99 (s, 1H), 12.64 (s, 1H); 13
C
J¼7.5 Hz, 1H), 8.55 (d, J¼8.0, 1.5 Hz, 1H), 13.99 (s, 1H); 13C NMR
NMR (CDCl3, 126 MHz)
d 113.8, 124.5, 124.7, 126.0, 126.9, 127.4,
(CDCl3, 126 MHz)
d
27.0, 55.4, 112.8, 113.8, 124.6, 125.3, 125.4, 125.8,
128.5, 129.3, 130.0, 130.7, 132.1, 135.9, 139.5, 161.1, 196.4; HRMS (ESI)
125.9, 130.0, 130.6, 131.1, 132.3, 136.0, 158.9, 161.6, 204.5; HRMS
calcd for C17H12NaO2 [MþNa]þ 271.0730, found 271.0730; IR (
n/
(ESI) calcd for C19H16NaO3 [MþNa]þ 315.0992, found 315.0993; IR
cmꢁ1): 3433, 1635, 764.
(n
/cmꢁ1): 3433, 1628, 1512, 1389, 1234.
4.2.8. 2-Benzoyl-4-phenyl-1-naphthol (2h). According to the gen-
eral procedure, 1h (31.4 mg, 0.102 mmol), (t-BuXPhos)AuNTf2
(1.8 mg, 2.0 mmol), and Ph2SO (52.7 mg, 0.261 mmol) were reacted
4.2.3. 2-Acetyl-4-(4-chlorophenyl)-1-naphthol (2c). According to
the general procedure, 1c (29.1 mg, 0.104 mmol), (t-BuXPhos)
AuNTf2 (1.8 mg, 2.0
m
mol), and Ph2SO (50.9 mg, 0.252 mmol) were
in 1,2-dichloroethane (1.0 mL): rt for 12 h. Purification by pre-
parative TLC on silica gel (hexane/AcOEt¼8:1) afforded 2h (7.1 mg,
reacted in 1,2-dichloroethane (1.0 mL): rt for 12 h. Purification by
preparative TLC on silica gel (hexane/AcOEt¼10:1) afforded 2c
(24.4 mg, 0.082 mmol, 79%) as a yellow solid. Mp 145e147 ꢀC; 1H
NMR (CDCl3, 500 MHz)
(m, 2H), 7.52e7.64 (m, 3H), 7.70e7.76 (m, 1H), 8.52e8.59 (m, 1H),
14.03 (s, 1H); 13C NMR (CDCl3, 75.6 MHz)
26.9, 112.7, 124.8, 125.4,
0.022 mmol, 21%) as
a
yellow solid. Mp 161e164 ꢀC (lit.
160e161 ꢀC;11a 156e157 ꢀC11b); 1H NMR (CDCl3, 500 MHz)
7.37e7.64 (m, 11H), 7.72e7.77 (m, 2H), 7.79e7.84 (m, 1H),
d
2.70 (s, 3H), 7.35e7.43 (m, 2H), 7.43e7.51
d
8.60e8.65 (m, 1H), 13.97 (s, 1H). The spectral data matched those
d
reported in the literature.11
125.6, 126.0, 128.4, 128.6, 130.1, 130.3, 131.4, 133.4, 135.6, 138.4,
162.1, 204.3; HRMS (ESI) calcd for
319.0496, found 319.0496; IR (
C
18H13ClNaO2 [MþNa]þ
4.2.9. 2-Acetyl-6-fluoro-4-phenyl-1-naphthol (2i). According to the
general procedure, 1i (26.8 mg, 0.101 mmol), (t-BuXPhos)AuNTf2
n
/cmꢁ1): 3442, 1619, 1398, 767.
(1.8 mg, 2.0 mmol), and Ph2SO (50.8 mg, 0.251 mmol) were reacted
4.2.4. 2-Butyryl-4-phenyl-1-naphthol (2d). According to the general
procedure, 1d (30.9 mg, 0.113 mmol), (t-BuXPhos)AuNTf2 (1.8 mg,
2.0 mmol), and Ph2SO (50.6 mg, 0.250 mmol) were reacted in 1,2-
in 1,2-dichloroethane (1.0 mL): rt for 12 h. Purification by pre-
parative TLC on silica gel (hexane/AcOEt¼8:1) afforded 2i (14.7 mg,
0.052 mmol, 52%) as a white solid. Mp 140e141 ꢀC; 1H NMR (CDCl3,
dichloroethane (1.0 mL): rt for 12 h. Purification by preparative TLC
on silica gel (hexane/AcOEt¼10:1 then 15:1) afforded 2d (20.6 mg,
0.071 mmol, 63%) as a pale yellow solid. Mp 142e144 ꢀC; 1H NMR
301 MHz) d 2.70 (s, 3H), 7.24e7.56 (m, 7H), 7.61 (s, 1H), 8.56 (dd,
J¼9.0, 6.3 Hz, 1H), 14.06 (s, 1H); 13C NMR (CDCl3, 126 MHz)
d 26.9,
2
110.1 (2JCeF¼22.4 Hz), 112.5, 115.8 (d, JCeF¼25.3 Hz), 122.2, 126.8,
3
4
(CDCl3, 500 MHz)
(t, J¼7.2 Hz, 2H), 7.42e7.63 (m, 8H), 7.79 (d, J¼8.0 Hz, 1H), 8.53e8.58
(m, 1H), 14.16 (s, 1H); 13C NMR (CDCl3, 126 MHz)
13.9, 18.0, 40.5,
d
1.04 (t, J¼7.3 Hz, 3H),1.84 (sext, J¼7.4 Hz, 2H), 3.05
127.6, 127.8 (d, JCeF¼9.4 Hz), 128.6, 129.9, 130.3 (d, JCeF¼5.1 Hz),
137.7 (d, 3JCeF¼9.4 Hz),139.5,161.7,163.7 (d, 1JCeF¼250.7 Hz), 204.3;
HRMS (ESI) calcd for C18H13FNaO2 [MþNa]þ 303.0792, found
d
112.4, 124.7, 125.0, 125.5, 125.82, 125.84, 127.3, 128.4, 130.0, 130.1,
130.8, 135.6, 140.1, 161.9, 206.7; HRMS (ESI) calcd for C20H18NaO2
303.0791; IR (n
/cmꢁ1): 3433, 1620, 1265.
[MþNa]þ 313.1199, found 313.1198; IR (
n
/cmꢁ1): 3433, 1620, 1389.
4.2.10. 2-Acetyl-6,7-methylenedioxy-4-phenyl-1-naphthol
(2j). According to the general procedure, 1j (28.7 mg, 0.099 mmol),
4.2.5. 2-Acetyl-4-methyl-1-naphthol (2e). According to the general
procedure, 1e (17.9 mg, 0.097 mmol), (t-BuXPhos)AuNTf2 (1.8 mg,
2.0 mmol), and Ph2SO (51.5 mg, 0.255 mmol) were reacted in 1,2-
dichloroethane (1.0 mL): rt for 12 h. Purification by preparative
TLC on silica gel (hexane/AcOEt¼10:1) afforded 2e (14.3 mg,
0.071 mmol, 74%) as a yellow solid. Mp 121e122 ꢀC; 1H NMR (CDCl3,
(t-BuXPhos)AuNTf2 (1.9 mg, 2.1 mmol), and Ph2SO (51.0 mg,
0.252 mmol) were reacted in 1,2-dichloroethane (1.0 mL): rt for 12 h.
Purification by preparative TLC on silica gel (hexane/AcOEt¼8:1, two
times) afforded 2j (18.5 mg, 0.060 mmol, 61%) as a pale yellow solid.
Mp 171e174 ꢀC; 1H NMR (CDCl3, 500 MHz)
d
2.66 (s, 3H), 6.06 (s, 2H),
7.07 (s, 1H), 7.40e7.52 (m, 6H), 7.80 (s, 1H), 13.80 (s, 1H); 13C NMR
(CDCl3, 126 MHz) 26.8, 101.2, 101.6, 103.0, 112.4, 121.4, 124.7, 127.3,
500 MHz)
1H), 7.69 (t, J¼7.7 Hz, 1H), 7.90 (d, J¼8.5 Hz, 1H), 8.50 (d, J¼8.0 Hz,
1H), 13.88 (s, 1H); 13C NMR (CDCl3, 126 MHz)
30.6, 36.9, 105.6,
d
2.60 (s, 3H), 2.70 (s, 3H), 7.46 (s, 1H), 7.56 (t, J¼7.5 Hz,
d
128.5, 130.0, 130.3, 134.0, 140.3, 147.4, 151.0, 160.5, 204.2; HRMS (ESI)
d
calcd for C19H14NaO4 [MþNa]þ 329.0784, found 329.0785; IR (
n/
114.6,114.7, 115.0,115.3,115.6,115.9,119.3,124.7, 144.3,178.7; HRMS
cmꢁ1): 3440, 1620, 1466, 1250.
(ESI) calcd for C13H12NaO2 [MþNa]þ 223.0730, found 223.0735; IR
(n
/cmꢁ1): 3433, 1620, 1234, 848, 764.
4.2.11. 2-Acetyl-4-phenylphenanthren-1-ol (2k). According to the
general procedure, 1k (29.2 mg, 0.099 mmol), (t-BuXPhos)AuNTf2
4.2.6. 2-Formyl-4-methyl-1-naphthol (2f). According to the general
procedure, 1f (17.4 mg, 0.102 mmol), (t-BuXPhos)AuNTf2 (2.0 mg,
(1.7 mg, 1.9
mmol), and Ph2SO (50.2 mg, 0.248 mmol) were reacted in
1,2-dichloroethane (1.0 mL): rt for 12 h. Purification by preparative

T. Matsuda et al. / Tetrahedron 71 (2015) 869e874
873
TLC on silica gel (hexane/AcOEt¼10:1) afforded 2k (27.4 mg,
0.088 mmol, 89%) as a yellow solid. Mp 191e194 ꢀC; 1H NMR (CDCl3,
2.5 Hz, 1H), 7.41 (d, J¼2.5 Hz, 1H), 7.54e7.58 (m, 1H), 7.71e7.77
(m, 1H), 8.42 (d, J¼9.0 Hz, 1H), 8.46 (d, J¼8.5 Hz, 1H), 8.51 (dd,
500 MHz)
d
2.72 (s, 3H), 7.12 (t, J¼7.5 Hz, 1H), 7.38e7.43 (m, 2H),
J¼8.0, 1.0 Hz, 1H), 14.80 (s, 1H); 13C NMR (CDCl3, 126 MHz)
d 31.6,
7.45e7.53 (m, 4H), 7.66 (s, 1H), 7.72 (d, J¼9.0 Hz, 1H), 7.83 (d,
55.4, 108.8, 111.9, 112.7, 120.3, 121.9, 124.4, 124.9, 125.4, 126.1,
131.1, 131.3, 134.3, 158.6, 163.8, 203.8; HRMS (ESI) calcd for
J¼8.5 Hz, 1H), 7.87 (d, J¼8.0 Hz, 1H), 8.46 (d, J¼9.5 Hz, 1H), 13.61 (s,
1H); 13C NMR (CDCl3,126 MHz)
d
26.9,114.0,121.0,124.3,125.0,127.2,
C
17H14NaO3 [MþNa]þ 289.0835, found 289.0837; IR (
n
/cmꢁ1):
127.4, 127.6, 128.5, 128.7, 129.1, 129.2, 129.6, 129.9, 131.0, 134.1, 135.0,
3433, 1612, 1219, 764.
144.7, 160.3, 204.4; HRMS (ESI) calcd for C22H16NaO2 [MþNa]þ
335.1043, found 335.1043; IR (
n
/cmꢁ1): 3433, 1635, 1234, 756.
4.2.17. 10-Benzoylphenanthren-9-ol (2q). According to the general
procedure, 1q (28.9 mg, 0.102 mmol), (t-BuXPhos)AuNTf2 (1.9 mg,
4.2.12. 6-Acetyl-4-phenylbenzo[b]thiophen-7-ol (2l). According to
the general procedure, 1l (25.5 mg, 0.101 mmol), (t-BuXPhos)
AuNTf2 (1.8 mg, 2.0 mmol), and Ph2SO (50.5 mg, 0.250 mmol) were
2.1 mmol), pyridine N-oxide (23.7 mg, 0.249 mmol), and cam-
phorsulfonic acid (34.8 mg, 0.150 mmol) were reacted in p-xylene
(1.0 mL): 120 ꢀC for 12 h. Purification by preparative TLC on silica
gel (hexane/AcOEt/toluene¼95:5:1) afforded 2q (17.5 mg,
0.059 mmol, 57%) as a yellow solid. Mp 137e138 ꢀC; 1H NMR
reacted in 1,2-dichloroethane (1.0 mL): rt for 12 h. Purification by
preparative TLC on silica gel (hexane/AcOEt¼20:1, three times)
afforded 2l (9.0 mg, 0.034 mmol, 33%) as a yellow solid. Mp
(CDCl3, MHz)
d 7.15e7.20 (m, 1H), 7.33e7.43 (m, 4H), 7.51e7.56 (m,
171e175 ꢀC; 1H NMR (CDCl3, 301 MHz)
d
2.72 (s, 3H), 7.32e7.73 (m,
1H), 7.61e7.65 (m, 2H), 7.66e7.72 (m, 1H), 7.80e7.85 (m, 1H), 8.54
(d, J¼8.0 Hz, 1H), 8.57e8.64 (m, 2H), 12.76 (s, 1H). The spectral data
matched those reported in the literature.13
8H), 13.33 (s, 1H); 13C NMR (CDCl3, 126 MHz)
d
27.0, 113.9, 124.1,
126.1, 127.4, 128.7, 128.9, 129.0, 129.1, 132.2, 140.0, 144.5, 158.1,
204.6; HRMS (ESI) calcd for C16H12NaO2S [MþNa]þ 291.0450, found
291.0449; IR (
n
/cmꢁ1): 3433, 1620, 1257.
4.2.18. 1-(2-Oxopropylidene)-3-phenyl-1H-indene (5). According to
the general procedure, 4 (23.9 mg, 0.097 mmol), (t-BuXPhos)
4.2.13. 6-Acetyl-8-phenylquinolin-5-ol (2m). According to the gen-
eral procedure, 1m (24.7 mg, 0.100 mmol), (t-BuXPhos)AuNTf2
AuNTf2 (1.8 mg, 2.0 mmol), and Ph2SO (50.7 mg, 0.251 mmol) were
reacted in 1,2-dichloroethane (1.0 mL): rt for 12 h. Purification by
preparative TLC on silica gel (hexane/AcOEt¼10:1) afforded 5
(15.9 mg, 0.065 mmol, 67%) as an amber oil. 1H NMR (CDCl3,
(1.8 mg, 2.0 mmol), and Ph2SO (50.7 mg, 0.251 mmol) were reacted
in p-xylene (1.0 mL): at 120 ꢀC for 12 h. Purification by preparative
TLC on silica gel (hexane/AcOEt¼8:1) afforded 2m (4.8 mg,
0.018 mmol, 18%) as a pale yellow solid. Mp 202e205 ꢀC; 1H NMR
500 MHz)
(m, 1H), 7.40e7.52 (m, 5H), 7.61 (d, J¼6.5 Hz, 1H), 7.68e7.72 (m,
2H); 13C NMR (CDCl3, 126 MHz)
31.9, 119.7, 120.5, 121.3, 124.0,
d 2.46 (s, 3H), 6.84 (s, 1H), 7.22e7.27 (m, 1H), 7.30e7.35
(CDCl3, 301 MHz)
2H), 7.90 (s, 1H), 8.83 (dd, J¼8.3, 1.7 Hz, 1H), 9.03 (dd, J¼4.4, 1.7 Hz,
1H), 13.92 (s, 1H); 13C NMR (CDCl3, 75.6 MHz)
27.1, 113.4, 120.82,
d
2.75 (s, 3H), 7.38e7.56 (m, 4H), 7.65 (d, J¼6.9 Hz,
d
126.5, 127.6, 128.7, 129.1, 129.7, 134.6, 138.4, 142.3, 149.0, 152.6,
d
198.7; HRMS (ESI) calcd for C18H14NaO [MþNa]þ 269.0937, found
120.84, 127.4, 128.2, 129.1, 130.4, 131.9, 133.1, 138.9, 149.6, 153.4,
269.0942; IR (n
/cmꢁ1): 1682, 1604, 756.
161.4, 204.5; HRMS (ESI) calcd for C17H14NO2 [MþNa]þ 264.1019,
found 264.1019; IR (
n
/cmꢁ1): 3433, 1620, 1396.
4.2.19. 3-Acetyl-1-phenylnaphthalene (7a). According to the gen-
eral procedure, 6a (24.9 mg, 0.100 mmol), (t-BuXPhos)AuNTf2
4.2.14. 6a-Acetylbenzo[b]bicyclo[3.1.0]hexan-6-one (3). According to
the general procedure,1n (17.0 mg, 0.100 mmol), (t-BuXPhos)AuNTf2
(1.8 mg, 2.0 mmol), and Ph2SO (51.1 mg, 0.253 mmol) were reacted
in 1,2-dichloroethane (1.0 mL): rt for 12 h. Purification by pre-
parative TLC on silica gel (hexane/AcOEt¼8:1) afforded 7a (10.3 mg,
(1.8 mg, 2.0
1,2-dichloroethane (1.0 mL): rt for 16 h. Purification by preparative
TLC on silica gel (hexane/AcOEt¼10:1) afforded (8.6 mg,
0.046 mmol, 46%) as a colorless oil. 1H NMR (CDCl3, 500 MHz)
1.80
mmol), and Ph2SO (50.6 mg, 0.250 mmol) were reacted in
0.042 mmol, 42%) as a colorless oil. 1H NMR (CDCl3, 500 MHz)
d 2.76
3
(s, 3H), 7.43e7.60 (m, 7H), 7.90e7.95 (m, 1H), 7.98 (d, J¼2.5 Hz, 1H),
8.02e8.06 (m, 1H), 8.49 (s, 1H). The spectral data matched those
reported in the literature.14
d
(dd, J¼4.5, 3.5 Hz, 1H), 2.42 (dd, J¼7.5, 3.5 Hz, 1H), 2.61 (s, 3H), 3.42
(dd, J¼7.5, 4.5 Hz, 1H), 7.35 (dt, J¼1.5, 7.5 Hz, 1H), 7.44 (d, J¼7.5 Hz,
1H), 7.52 (dt, J¼1.5, 7.5 Hz, 1H), 7.71 (d, J¼7.5 Hz, 1H); 13C NMR
4.2.20. 2-Acetyl-1-methyl-4-phenylnaphthalene (7b). According to
the general procedure, 6b (26.2 mg, 0.100 mmol), (t-BuXPhos)
AuNTf2 (1.8 mg, 2.0 mmol), and Ph2SO (50.5 mg, 0.250 mmol) were
reacted in 1,2-dichloroethane (1.0 mL): rt for 12 h. Purification by
preparative TLC on silica gel (hexane/AcOEt¼8:1) afforded 7b
(9.7 mg, 0.037 mmol, 37%) as a colorless oil. 1H NMR (CDCl3,
(CDCl3, 126 MHz)
d 29.8, 34.6, 43.5, 46.2, 124.4, 125.2, 127.7, 134.2,
134.3, 151.6, 198.2, 202.1; HRMS (ESI) calcd for C12H10NaO2 [MþNa]þ
209.0573, found 209.0569; IR (
n
/cmꢁ1): 1726, 1344, 1168.
4.2.15. 10-Acetylphenanthren-9-ol (2o). According to the general
procedure, 1o (21.1 mg, 0.096 mmol), (t-BuXPhos)AuNTf2 (1.9 mg,
500 MHz)
d 2.67 (s, 3H), 2.84 (s, 3H), 7.43e7.53 (m, 7H), 7.57e7.63
2.1
m
mol), and Ph2SO (50.8 mg, 0.251 mmol) were reacted in p-
(m, 1H), 7.91 (d, J¼8.0 Hz, 1H), 8.24 (d, J¼8.5 Hz, 1H); 13C NMR
xylene (1.0 mL): 120 ꢀC for 12 h. Purification by preparative TLC on
silica gel (hexane/AcOEt¼10:1) afforded 2o (10.4 mg, 0.044 mmol,
46%) as a pale yellow solid. Mp 95e98 ꢀC; 1H NMR (CDCl3,
(CDCl3, 126 MHz) d 15.8, 30.9, 124.8, 125.5, 126.5, 126.6, 127.1, 127.5,
128.3, 130.1, 132.4, 132.9, 133.2, 136.6, 138.6, 140.2, 204.3; HRMS
(ESI) calcd for C19H16NaO [MþNa]þ 283.1093, found 283.1091; IR (
n/
500 MHz)
d
2.85 (s, 3H), 7.52 (t, J¼7.2 Hz, 1H), 7.58 (t, J¼7.2 Hz, 1H),
cmꢁ1): 1598, 1541, 1536, 755, 681.
7.65 (t, J¼7.5 Hz, 1H), 7.76e7.83 (m, 1H), 8.01 (d, J¼8.5 Hz, 1H),
8.53e8.60 (m, 3H), 14.7 (s, 1H). The spectral data matched those
reported in the literature.12
Acknowledgements
This work was supported by Japan Society for the Promotion of
Science, Japan (Grant-in-Aid for Scientific Research (C) No.
25410054) and the Sumitomo Foundation (No. 130325).
4.2.16. 10-Acetyl-2-methoxyphenanthren-9-ol (2p). According to
the general procedure, 1p (25.2 mg, 0.101 mmol), (t-BuXPhos)
AuNTf2 (1.9 mg, 2.1
mmol), and Ph2SO (50.6 mg, 0.250 mmol)
were reacted in p-xylene (1.0 mL): 120 ꢀC for 12 h. Purification by
preparative TLC on silica gel (toluene) afforded 2p (8.0 mg,
0.030 mmol, 30%) as yellow solid. Mp 109e110 ꢀC; 1H NMR
Supplementary data
Copies of 1H and 13C NMR spectra for all products. Supple-
mentary data associated with this article can be found in the online
(CDCl3, 500 MHz)
d
2.85 (s, 3H), 3.95 (s, 3H), 7.12 (dd, J¼9.5,

874
T. Matsuda et al. / Tetrahedron 71 (2015) 869e874
2014, 43, 2941; (w) Xie, J.; Pan, C.; Abdukader, A.; Zhu, C. Chem. Soc. Rev. 2014,
43, 5245.
version, at http://dx.doi.org/10.1016/j.tet.2014.12.041. These data
include MOL files and InChiKeys of the most important compounds
described in this article.
3. For gold-catalyzed reactions using external organic oxides, see: (a) Witham, C.
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