Phosphorous acid-catalyzed alkylation of phenols with alkenes

Article abstract of DOI:10.1021/acs.joc.9b03028

A H₃PO₃-catalyzed alkylation of phenols with alkenes is achieved in a facile, efficient, and selective manner. The reaction shows a unique selectivity, i.e., excellent regioselectivity, thorough suppression of overalkylation, without alkylation of a simple phenyl ring, and can selectively provide ortho-, meta-, or para-alkylated phenol derivatives in good to excellent yields. This feature along with mild reaction conditions, sensitive functional group tolerance, and scale-up synthesis and late modification of phenolic bioactive compounds make it an ideal and practical alternative for the modification of phenols.

Full text of DOI:10.1021/acs.joc.9b03028

Subscriber access provided by BIU Pharmacie | Faculté de Pharmacie, Université Paris V
Article
Phosphorous Acid Catalyzed Alkylation of Phenols with Alkenes
Shaofeng Wu, Jianyu Dong, Dan Zhou, Wan Wang, Long Liu, and Yongbo Zhou
J. Org. Chem., Just Accepted Manuscript • DOI: 10.1021/acs.joc.9b03028 • Publication Date (Web): 25 Dec 2019
Downloaded from pubs.acs.org on December 26, 2019
Just Accepted
“Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted
online prior to technical editing, formatting for publication and author proofing. The American Chemical
Society provides “Just Accepted” as a service to the research community to expedite the dissemination
of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in
full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully
peer reviewed, but should not be considered the official version of record. They are citable by the
Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore,
the “Just Accepted” Web site may not include all articles that will be published in the journal. After
a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web
site and published as an ASAP article. Note that technical editing may introduce minor changes
to the manuscript text and/or graphics which could affect content, and all legal disclaimers and
ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or
consequences arising from the use of information contained in these “Just Accepted” manuscripts.
is published by the American Chemical Society. 1155 Sixteenth Street N.W.,
Washington, DC 20036
Published by American Chemical Society. Copyright © American Chemical Society.
However, no copyright claim is made to original U.S. Government works, or works
produced by employees of any Commonwealth realm Crown government in the
course of their duties.

Page 1 of 9
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
Phosphorous Acid Catalyzed Alkylation of Phenols with Alkenes
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Shaofeng Wu,a Jianyu Dong,b Dan Zhou,a Wan Wang,a Long Liu,a,c and Yongbo Zhou,a,*
aCollege of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
bDepartment of Educational Science, Hunan First Normal University, Changsha 410205, China
cKey Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources, School of Chemical Engi-
neering and Technology, Hainan University, Haikou 570228, China
*E-mail: zhouyb@hnu.edu.cn.
Supporting Information Placeholder
ABSTRACT: A H3PO3 catalyzed alkylation of phenols with alkenes is achieved in a facile, efficient, and selective manner. The
reaction shows a unique selectivity, i.e., excellent regioselectivity, thorough suppression of over-alkylation, without alkylation of
simple phenyl ring, and can selectively prepare ortho-, meta-, or para-alkylated phenol derivatives with good to excellent yields.
This merit along with mild reaction conditions, sensitive functional group tolerance, and scale-up synthesis, as well as late-
modification of phenolic bioactive compounds make it an ideal and practical alternative for the modification of phenols.
phenolic resin that is derived from a simple phenol is con-
sumed at a rate of millions tons per year (Figure 1). In this
regard, the facile and selective functionalization of simple
phenols, which would enhance the diversity and applications
of these compounds, is of great importance.
Introduction
Phosphorous acid (H3PO3) is an affordable, readily availa-
ble, relatively lowly acidic and corrosive Brønsted acid. Com-
pared with organophosphorus acids that are extensively used
in organic synthesis,1 H3PO3 catalysis is underdeveloped.2,3
Over the past years, we have focused our research interest on
H3PO3 catalysis, and have acknowledged that H3PO3 could act
as both Lewis acid and base, which often shows interesting
effects in some acid catalyzed reactions.3 Herein, as a result of
our continued interest in H3PO3 catalysis, we report a facile,
efficient and selective alkylation reaction of phenols with al-
kenes toward various alkylated phenols (Scheme 1).
Figure 1. Representative phenol derivatives.
Scheme 1. Selective Alkylation of Phenols with Alkenes via
H3PO3 Catalysis
Among the numerous efforts on the selective functionaliza-
tion of phenols,5 the catalytic alkylation of phenols with al-
kenes6–12 is one of the most promising approaches because it
could form industrially useful alkylated phenols directly from
easily available starting materials.9 Typically, the reaction
proceeds via Friedel-Crafts type alkylation, which is generally
catalyzed by strong Lewis acids (TiCl4, AlCl3, FeCl3, and
ZnBr2) and Brønsted acids (HF and H2SO4).6,7 Acidic materi-
als such as graphene,8 zeolite,10 mesoporous and nanoporous
materials11 as well as amberlyst resin12 have also been success-
Phenol derivatives are among the most basic chemicals and
are widely applied in pharmaceuticals, agrochemicals, dyes,
and adhesives, as well as polymeric materials.4 For example,
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 2 of 9
1
2
3
4
5
6
7
8
9
fully developed as catalysts in this reaction. Recently, the tran-
entries 12–14), whereas it did not occur in strongly polar sol-
vents (CH3CN and DMF; Table 1, entries 15 and 16). A 69%
yield of 3a was obtained by a half loading of H3PO3 (10
mol %, Table 1, entry 17). Reaction temperature was also ex-
amined, but no better results were observed (Table 1, entries
18 and 19). In view of the oxidation potential of phenols, we
finally investigated the effect of air on the reaction. Surpris-
ingly, a comparable yield of 3a (92%) was obtained (Table 1,
entry 20 vs entry 2) by conduction of this reaction under air.
This well compatibility of both water- and air-conditions
demonstrated the easy operation of this alkylation reaction.
sition metal (Rh-,13 Ir-,14 and Re-15) catalyzed addition of phe-
nols to alkenes via C‒H bond activation has emerged as a
good alternative to this type of reaction. Despite notable ad-
vances, these reported methods generally suffer from some
drawbacks, such as harsh reaction conditions, the requirement
of an excess of one substrate (2–10 equiv), poor functional
group compatibility, and/or tedious preparation of the catalyst
materials. Therefore, due to the extensive applications of al-
kylated phenols, the development of new methods of alkyla-
tion to address these issues is highly desirable.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
With the optimized conditions in hand, the scope and gen-
erality of this reaction were investigated. As shown in Scheme
2, this H3PO3-catalyzed reaction produced the alkylated prod-
ucts in good to excellent yields with a broad substrate scope
and remarkable functional group tolerance. The reaction of 2-
naphthol (1a) with styrene (2a) gave the product 3a in an 89%
isolated yield. For 2-naphthols, valuable functional groups
such as CN (3b), CO2Me (3c), CHO (3d), COOH (3e), and Br
(3f) were tolerated, furnishing the corresponding products in
85–93% yields with excellent selectivity (>99%). Notably,
although CN (3b) and CO2Me (3c) are easily hydrolyzed, and
CHO (3d) can react with phenols under strong acidic condi-
tions, they were well tolerated. The compatibility of our condi-
tions with CHO and COOH is useful and is the first report of
this type of reaction. In addition to naphthols, phenols with
electron-donating groups were also good substrates for the
reaction, and the corresponding single-alkylated products were
obtained in 73–93% yields (3g–l) with tolerance of methyl,
methoxy, thiomethyl, tert-butyl, and phenyl groups. Phenols
with electron-withdrawing groups gave lower yields of the
products (3m, 44%; 3n, 41%).
Results and Discussion
Fortunately, by the direct treatment of 2-naphthol (1a) with
styrene (2a, 1.2 equiv) in the presence of H3PO3 (20 mol %,
50% aq.) in DCE at 100 ºC under N2, the desired ortho-
alkylated product 1-(1-phenylethyl)naphthalen-2-ol (3a) was
produced in 92% GC yield with >96% position-selectivity
(Table 1, entry 2). The investigations of the catalytic perfor-
mance of other acid catalysts showed that the phosphorus-
containing inorganic acids had unique performance for the
electrophilic addition reaction (Table 1, entries 1–3). In com-
parison, typical Brønsted acids and Lewis acids, such as
H2C2O4, TsOH, H2SO4, TFA, HOAc, FeCl3, CuCl2, and AlCl3
that are efficient catalysts in other catalytic systems6,7 were not
compatible under the mild reaction conditions (Table 1, entries
4–11). This result demonstrated an attractive merit of H3PO3
catalysis, which allowed for the reaction taking place under
mild conditions. The reaction proceeded smoothly in weakly
polar solvents such as PhCl, hexane, and toluene (Table 1,
Table 1. Optimization of the Reaction Conditionsa
The reaction showed an interesting selectivity. Reaction of
the simplest phenol with 2a under the optimized conditions
gave the para-alkylated product (3o) in 52% yield with the
ortho-alkylated product (3o') in 32% yield, which was con-
sistent with other reaction systems.6,7 In a sharp contrast, when
3,5-dimethylphenol that possesses both ortho- and para- elec-
trophilic sites was adopted in this reaction, an 86% yield of the
ortho-alkylated product (3p) was obtained with 95% regiose-
lectivity, and only a trace amount of the para-alkylated prod-
uct was observed. Interestingly, the reaction of o-cresol that
has an ortho-methyl group showed para-selectivity, and the
para-alkylated product (3q) was obtained in an 84% yield
with 90% regioselectivity. Notably, sesame phenol, which has
similar reactivity at the 2- and 6-positions, showed >99% se-
lectivity for the 6-position in the reaction (3r). Excellent 6-
position selectivity (>99%) has also been observed for the
substrate 3-tert-butyl phenol (3s). For 2,6-dimethoxyphenol,
the meta-alkylated product (3t) was predominately obtained
(82% yield with 91% selectivity), and this different regioselec-
tivity may be due to the OMe. It should be noted that although
alkylation products are more electron-rich, the over-alkylation
products were either not observed or only observed in trace
amounts (<1%) in the above reactions. The unique selectivity
was probably due to the dual roles of the phosphorous acid
(vide infra) and might be applied to selective synthesis of or-
tho-, meta-, or para-alkylated products, which cannot be easily
obtained by other methods.6–12 This catalytic system was also
suitable for polyhydroxy phenols. For example, hydroquinone
aReaction conditions: 1a (0.4 mmol), 2a (0.48 mmol, 1.2
equiv), catalyst (20 mol %) in solvent (2.0 mL) for 18 h under
N2. bGC yield using tridecane as an internal standard. ccatalyst
(10 mol %). dUnder air.
ACS Paragon Plus Environment

Page 3 of 9
The Journal of Organic Chemistry
1
2
3
Scheme 2. Substrate Scopea,b
was successfully transformed to the alkylated p-benzenediol
4
(3u) in 80% yield.
5
6
7
8
With respect to alkenes, terminal alkenes bearing both elec-
tron donating groups such as Me (3v–x) and tBu (3y) and elec-
tron withdrawing groups such as F (3z) and Cl (3za) on the
phenyl ring reacted smoothly with 2-naphthol to produce the
corresponding ortho-alkylated products in 60–96% yields.
Additionally, treatment of substituted terminal alkenes with
2,6-dimethoxyphenol gave the corresponding meta-alkylated
products in satisfactory yields (74–93%, 3zb–zd). Sterically
bulky naphthyl alkene and heteroaryl alkenes exemplified by
thienyl alkene also reacted with 2,6-dimethoxyphenol, and the
desired meta-alkylated products (3ze and 3zf) were produced
in 72% and 62% yields, respectively. In addition to terminal
alkenes, the reaction of internal alkenes with phenol was also
successful. For example, upon treatment of indene with 2,6-
dimethoxyphenol, the 4-alkylated-2,6-dimethoxyphenol prod-
uct (3zg) was produced in 73% yield. Additionally, aryl ethers
could also be alkylated, although lower yields were observed
(3zh–zj). Notably, the alkylation of the simple phenyl rings
was not observed in all of the reactions.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Scheme 3. Synthetic Utility
To further explore the utility of this H3PO3-catalytic system,
a scale-up reaction (80 mmol) of 1a with 2a was conducted.
After prolonging the reaction time (48 h), a good yield of 3a
(73%, 14.5 g) was obtained, which allows for potential indus-
trial applications of this transformation (Scheme 3, eq. 1).
Estrone is a key intermediate for the synthesis of estrogens
such as estradiol or ethinyloestradiol, and the alkylation of
estrone is relevant to drug modification. Satisfactorily, when
estrone 1zk was reacted with 2a under the optimized condi-
tions, the product (3zk) was obtained in 59% yield (Scheme 3,
eq. 2). Additionally, raspberry ketone 1zl could also be alkyl-
ated to product 3zl in 72% yield (Scheme 3, eq. 3).
Although the detailed reaction mechanism remains unclear,
we propose a possible mechanism (exemplified by ortho-
alkylation of phenols) on the basis of the above observations
and literature reports.1 As shown in Scheme 4, the reaction
proceeds via Friedel-Crafts type alkylation. Alkene 2 reacts
with phosphorous acid (H3PO3) to form carbenium ion inter-
mediate A, releasing phosphorous anion (H2PO3‾). The inter-
action of H2PO3‾ with phenol 1 and A forms intermediate B,1
which undergoes intramolecular electrophilic addition, form-
ing intermediate C. Finally, deprotonation of C gives the de-
sired product 3. It is noted that the reaction position of the
intramolecular electrophilic addition of B is sensitive to the
aReaction conditions: 1 (0.4 mmol), 2 (0.48 mmol, 1.2 equiv),
H3PO3 (20 mol %) in DCE (2.0 mL) at 100 ºC for 18 h, under
b
air. Isolated yield of 3. Regioselectivity in paradigms (major
product/minor products) was determined by GC.
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 4 of 9
1
2
3
4
5
6
7
8
9
steric and electronic nature the substituents on the aryl rings
for this reaction, which can lead to ortho-, meta-, or para-
regioselectivity, respectively.
An Schlenk tube of 25 mL equipped with a magnetic stir
bar was charged with phenol 1 (0.4 mmol), alkene 2 (0.48
mmol, 1.2 equiv), H3PO3 (50% aq. 20 mol %), DCE (2.0 mL).
The reaction mixture was heated at 100 °C for 18 h. After
completion of the reaction, the reaction mixture was cooled to
room temperature, and the volatiles were removed under re-
duced pressure. The crude reaction mixture was purified over
silica-gel (300‒400 mesh) column chromatography using pe-
troleum ether, ethyl acetate, or dichloromethane as eluent.
Scheme 4. Possible Reaction Mechanism
H
OH
P
HO
O
O
O
H
Ar
H
O
P
H
Ar
Ar
2
A
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
H
P
O
OH
O
O
OH
R
B
Characterization Data for the Products
H2PO3
Ar
1
R
1–(1–Phenylethyl)–2–naphthalenol (3a).16 The title com-
pound was prepared according to the general procedure and
purified by column chromatography on silica gel and eluted
with petroleum ether/dichloromethane (1/1) to afford a pale
yellow oil in 89% yield (88.3 mg). 1H NMR (400 MHz,
CDCl3): δ 8.03 (d, J = 8.6 Hz, 1H), 7.79 (d, J = 8.0 Hz, 1H),
7.66 (d, J = 8.7 Hz, 1H), 7.45 (t, J = 7.2 Hz, 1H), 7.39 – 7.31
(m, 5H), 7.26 – 7.22 (m, 1H), 6.99 (d, J = 8.8 Hz, 1H), 5.17 (q,
J = 6.8 Hz, 1H), 1.78 (d, J =7.2 Hz, 3H); 13C NMR (101 MHz,
CDCl3): δ 151.5, 143.7, 132.8, 129.7, 129.0, 128.8, 128.7,
127.1, 126.7, 126.5, 123.8, 123.1, 122.7, 119.3, 34.8, 17.1.
Ar
H2PO3
H
R
OH
OH
H3PO3
R
3
C
In conclusion, we have developed a facile and efficient al-
kylation reaction for phenols with alkenes that yields alkylated
phenols by using the affordable, stable, readily available, rela-
tively lowly acidic and weakly corrosive H3PO3 as the catalyst.
H3PO3 probably acts as both Lewis acid and base. These ef-
fects allow for the reaction to occur with high efficiency under
very simple conditions, in which the commonly used catalysts
are ineffective. The reaction shows a broad substrate scope
and outstanding functional group tolerance. In particular, this
represents the first reported reaction of its type to show com-
patibility with CHO and COOH groups. Excellent regioselec-
tivity is observed for positions that have similar reactivity, and
alkylation of simple aryl rings and over-alkylation is thor-
oughly suppressed for the reaction. Thus, all of the ortho-,
meta-, and para-alkylated phenol derivatives can be selective-
ly prepared by this method. The scale-up reaction and the late-
modification of the medical intermediates estrone and raspber-
ry ketone have also been successfully conducted. Taking into
account the merits of the reaction, such as mild reaction condi-
tions, broad scope of the substrates, nearly equivalent molar
ratio of the substrates, broad functional group tolerance, high
regioselectivity, and scale-up synthesis, as well as late-
modification of phenolic bioactive compounds, this conven-
ient method offers an ideal and practical alternative for the
modification of phenols.
6–isocyano–1–(1–phenylethyl) naphthalen–2–ol (3b). The
title compound was prepared according to the general proce-
dure and purified by column chromatography on silica gel and
eluted with petroleum ether/dichloromethane (1/1) to afford a
pale yellow oil in 93% yield (101.6 mg). 1H NMR (400 MHz,
CDCl3): δ 8.15 (s, 1H), 8.03 (d, J = 9.2 Hz, 1H), 7.71 (d, J =
8.8 Hz, 1H), 7.53 (d, J = 8.8 Hz, 1H), 7.35 – 7.34 (m, 4H),
7.28 – 7.25 (m, 1H), 7.15 (d, J = 8.8 Hz, 1H), 5.63 (s, 1H),
5.16 (q, J = 6.8 Hz, 1H), 1.78 (d, J = 6.8 Hz, 3H); 13C NMR
(101 MHz, CDCl3): δ 154.3, 143.1, 134.9, 134.6, 129.3, 129.1,
128.5, 127.0, 126.9, 126.9, 124.4, 124.2, 120.9, 119.5, 106.0,
34.7, 17.2. HRMS (EI) m/z: [M]+ calcd. for C19H15NO:
273.1154; found: 273.1150.
methyl 6–hydroxy–5–(1–phenylethyl)–2–naphthoate (3c).
The title compound was prepared according to the general
procedure and purified by column chromatography on silica
gel and eluted with petroleum ether/dichloromethane (1/1) to
1
afford a pale yellow oil in 91% yield (111.4 mg). H NMR
(400 MHz, CDCl3): δ 8.54 (s, 1H), 8.04 – 7.98 (m, 2H), 7.76
(d, J = 8.8 Hz, 1H), 7.37 – 7.31 (m, 4H), 7.26 – 7.23 (m, 1H),
7.09 (d, J = 8.8 Hz, 1H), 5.56 (bs, 1H), 5.19 (q, J = 6.8 Hz,
1H), 3.96 (s, 3H), 1.79 (d, J = 7.2 Hz, 3H); 13C NMR (101
MHz, CDCl3): δ 167.5, 153.8, 143.4, 135.4, 132.0, 130.2,
129.0, 128.6, 127.1, 126.7, 125.8, 124.4, 124.1, 123.1, 120.0,
52.2, 34.8, 17.2. HRMS (EI) m/z: [M]+ calcd. for C20H18O3:
306.1256; found: 306.1250.
Experimental Section
General Information
The reactions were carried out in Schlenk tubes of 25 mL.
The heat source is IKA magnetic stirrer with RCT Basic. Rea-
gents were used as received unless otherwise noted. Column
chromatography was performed using Silica Gel 60 (300‒400
mesh). The reactions were monitored by GC and GC-MS, GC-
MS results were recorded on GC-MS QP 2010, and GC analy-
6-hydroxy-5-(1-phenylethyl)-2-naphthaldehyde (3d). The
title compound was prepared according to the general proce-
dure and purified by column chromatography on silica gel and
eluted with petroleum ether/dichloromethane (1/1) to afford a
1
sis was performed on GC 2010 plus. The H and 13C NMR
spectra were recorded on a Brucker ADVANCE III spectrom-
eter at 400 MHz and 100 MHz respectively, and chemical
shifts were reported in parts per million (ppm). The electron
ionization (EI) method was used as the ionization method for
the HRMS measurement, and the mass analyzer type is TOF
for EI. All solvents and reagents were purchased from Energy
Chemical, Alfa Aesar, and Aladdin.
1
pale yellow oil in 85% yield (93.8 mg). H NMR (400 MHz,
CDCl3): δ 10.10 (s, 1H), 8.29 (s, 1H), 8.10 (d, J = 8.8 Hz, 1H),
7.92 (d, J = 8.6 Hz, 1H), 7.83 (d, J = 8.8 Hz, 1H), 7.37 – 7.33
(m, 4H), 7.28 – 7.25 (m, 1H), 7.15 – 7.13 (m, 1H), 5.65 (s,
1H), 5.21 (q, J = 6.8 Hz, 1H), 1.80 (d, J = 7.2 Hz, 3H); 13C
NMR (101 MHz, CDCl3): δ 192.2, 154.6, 143.1, 136.4, 135.5,
131.5, 130.5, 129.1, 128.7, 127.1, 126.9, 124.6, 123.9, 123.6,
General Experimental Procedure
ACS Paragon Plus Environment

Page 5 of 9
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
120.4, 34.9, 17.2. HRMS (EI) m/z: [M]+ calcd. for C19H16O2:
276.1150; found: 276.1146.
2,4–dimethyl–6–(1–phenylethyl)phenol (3j).7d The title
compound was prepared according to the general procedure
and purified by column chromatography on silica gel and elut-
ed with petroleum ether/ethyl acetate (5/1) to afford a color-
6-hydroxy-5-(1-phenylethyl)-2-naphthoic acid (3e). The ti-
tle compound was prepared according to the general procedure
and purified by column chromatography on silica gel and elut-
ed with petroleum ether/dichloromethane (1/1) to afford a
1
less oil in 90% yield (81.4 mg). H NMR (400 MHz, CDCl3):
δ 7.30 – 7.24 (m, 4H), 7.21 – 7.17 (m, 1H), 6.91 (s, 1H), 6.83
(s, 1H), 4.41 (s, 1H), 4.29 (q, J = 7.2 Hz, 1H), 2.26 (s, 3H),
2.14 (s, 3H), 1.60 (d, J = 7.2 Hz, 3H); 13C NMR (101 MHz,
CDCl3): δ 149.4, 145.4, 131.1, 129.5, 129.3, 128.7, 127.5,
126.4, 126.0, 123.9, 39.1, 21.2, 20.7, 15.8.
1
colorless oil in 92% yield (107.5 mg). H NMR (400 MHz,
CDCl3): δ 8.64 (s, 1H), 8.07 (s, 2H), 7.80 (d, J = 8.7 Hz, 1H),
7.39 – 7.25 (m, 5H), 7.10 (d, J = 8.8 Hz, 1H), 5.20 (q, J = 7.2
Hz, 1H), 1.80 (d, J = 6.8 Hz, 3H); 13C NMR (101 MHz,
CDCl3): δ 172.1, 154.0, 143.3, 135.8, 132.9, 130.4, 129.1,
128.6, 127.1, 126.8, 126.1, 124.1, 123.9, 123.1, 120.2, 34.9,
17.1. HRMS (EI) m/z: [M]+ calcd. for C19H16O3: 292.1099;
found: 292.1097.
6–bromo–1–(1–phenylethyl) naphthalen–2–ol (3f).17 The
title compound was prepared according to the general proce-
dure and purified by column chromatography on silica gel and
eluted with petroleum ether/dichloromethane (1/1) to afford a
brown oil in 87% yield (113.8 mg). 1H NMR (400 MHz,
CDCl3): δ 7.92 (s, 1H), 7.86 (d, J = 9.2 Hz, 1H), 7.55 (d, J =
8.8 Hz, 1H), 7.48 (d, J = 9.2 Hz, 1H), 7.34 – 7.30 (m, 4H),
7.26 – 7.22 (m, 1H), 7.00 (d, J = 8.8 Hz, 1H), 5.13 – 5.09 (m,
1H), 5.06 (s, 1H), 1.76 (d, J = 7.2 Hz, 3H); 13C NMR (101
MHz, CDCl3): δ 151.7, 143.3, 131.4, 130.9, 130.6, 129.6,
129.0, 127.7, 127.0, 126.8, 124.7, 124.2, 120.3, 116.7, 34.8,
17.2.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
2,6–dimethyl–4–(1–phenylethyl) phenol (3k).7d The title
compound was prepared according to the general procedure
and purified by column chromatography on silica gel and elut-
ed with petroleum ether/ethyl acetate (5/1) to afford a color-
1
less oil in 86% yield (77.7 mg). H NMR (400 MHz, CDCl3):
δ 7.25 – 7.16 (m, 5H), 6.82 – 6.81 (m, 2H), 4.51 (s, 1H), 4.02
– 4.01 (m, 1H), 2.17 (s, 6H), 1.59 (d, J = 7.2 Hz, 3H); 13C
NMR (101 MHz, CDCl3): δ 150.3, 146.9, 138.0, 128.3, 127.7,
127.5, 125.8, 122.8, 44.0, 22.1, 16.0.
3,4,5–trimethoxy–2–(1–phenylethyl) phenol (3l). The title
compound was prepared according to the general procedure
and purified by column chromatography on silica gel and elut-
ed with petroleum ether/ethyl acetate (5/1) to afford a color-
less oil in 93% yield (107.1 mg). 1H NMR (400 MHz, CDCl3):
δ 7.36 – 7.30 (m, 4H), 7.22 – 7.19 (m, 1H), 6.15 (s, 1H), 4.77
(s, 1H), 4.71 (q, J = 7.2 Hz, 1H), 3.83 (s, 3H), 3.78 (s, 3H),
3.74 (s, 3H), 1.65 (d, J = 7.2 Hz, 3H); 13C NMR (101 MHz,
CDCl3): δ 152.2, 151.9, 150.2, 144.2, 136.1, 128.7, 127.1,
126.3, 118.5, 97.2, 61.1, 60.9, 55.7, 33.3, 17.8. HRMS (EI)
m/z: [M]+ calcd. for C17H20O4: 288.1362; found: 288.1367.
4–(tert–butyl)–2–(1–phenylethyl) phenol (3g).11c The title
compound was prepared according to the general procedure
and purified by column chromatography on silica gel and elut-
ed with petroleum ether/ethyl acetate (5/1) to afford a color-
1
less oil in 75% yield (76.2 mg). H NMR (400 MHz, CDCl3):
4-chloro-2-(1-phenylethyl)phenol (3m).11a The title com-
pound was prepared according to the general procedure and
purified by column chromatography on silica gel and eluted
with petroleum ether/dichloromethane (1/1) to afford a white
δ 7.30 – 7.23 (m, 5H), 7.20 – 7.16 (m, 1H), 7.12 (d, J = 8.0 Hz,
1H), 6.65 (d, J = 8.4 Hz, 1H), 4.61 (s, 1H), 4.34 (q, J = 7.2 Hz,
1H), 1.63 (d, J = 7.2 Hz, 3H), 1.29 (s, 9H); 13C NMR (101
MHz, CDCl3): δ 151.0, 145.5, 143.4, 131.0, 128.6, 127.5,
126.3, 124.9, 124.1, 115.4, 39.2, 34.2, 31.6, 21.0.
1
solid in 44% yield (40.8 mg). H NMR (400 MHz, CDCl3): δ
7.30 – 7.26 (m, 2H), 7.24 – 7.16 (m, 4H), 7.04 (dd, J = 8.5, 2.6
Hz, 1H), 6.61 (d, J = 8.5 Hz, 1H), 4.79 (s, 1H), 4.30 (q, J = 7.2
Hz, 1H), 1.58 (d, J = 7.2 Hz, 3H). 13C NMR (101 MHz,
CDCl3): δ 151.8, 144.5, 133.8, 128.8, 127.8, 127.4, 127.2,
126.7, 125.7, 117.2, 38.7, 20.8.
3–(1–phenylethyl)–[1,1'–biphenyl]–4–ol (3h). The title
compound was prepared according to the general procedure
and purified by column chromatography on silica gel and elut-
ed with petroleum ether/ethyl acetate (5/1) to afford a color-
1
less oil in 73% yield (80.0 mg). H NMR (400 MHz, CDCl3):
4-bromo-2-(1-phenylethyl)phenol (3n).11a The title com-
pound was prepared according to the general procedure and
purified by column chromatography on silica gel and eluted
with petroleum ether/ethyl acetate (10/1) to afford a colorless
δ 7.55 – 7.53 (m, 2H), 7.48 (s, 1H), 7.40 (t, J = 7.2 Hz, 2H),
7.35 – 7.29 (m, 6H), 7.21 (s, 1H), 6.79 (d, J = 8.4 Hz, 1H),
4.76 (s, 1H), 4.41 (q, J = 7.2 Hz, 1H), 1.67 (d, J = 7.2 Hz, 3H);
13C NMR (101 MHz, CDCl3): δ 152.9, 145.1, 141.1, 134.0,
132.1, 128.7, 128.7, 127.5, 126.8, 126.6, 126.5, 126.2, 116.3,
38.9, 21.0. HRMS (EI) m/z: [M]+ calcd. for C20H18O:
274.1358; found: 274.1353.
1
oil in 41% yield (45.3 mg). H NMR (400 MHz, CDCl3): δ
7.35 – 7.27 (m, 3H), 7.26 – 7.16 (m, 4H), 6.62 (d, J = 8.5 Hz,
1H), 4.86 (s, 1H), 4.31 (q, J = 7.2 Hz, 1H), 1.60 (d, J = 7.2 Hz,
3H). 13C NMR (101 MHz, CDCl3): δ 152.5, 144.4, 134.3,
130.7, 130.2, 128.8, 127.4, 126.7, 117.7, 113.1, 38.7, 20.9.
4-(methylthio)-2-(1-phenylethyl)phenol (3i). The title com-
pound was prepared according to the general procedure and
purified by column chromatography on silica gel and eluted
with petroleum ether/ethyl acetate (10/1) to afford a colorless
oil in 81% yield (79.1 mg). 1H NMR (400 MHz, CDCl3): δ
7.35 – 7.31 (m, 2H), 7.29 – 7.26 (m, 4H), 7.13 (dd, J = 8.3 Hz,
J = 2.3 Hz, 1H), 6.74 (d, J = 8.3 Hz, 1H), 4.74 (s, 1H), 4.36 (q,
J = 7.2 Hz, 1H), 2.47 (s, 3H), 1.65 (d, J = 7.4 Hz, 3H). 13C
NMR (101 MHz, CDCl3): δ 152.0, 144.8, 132.7, 128.9, 128.8,
128.7, 128.0, 127.5, 126.6, 116.8, 38.9, 20.9, 18.1. HRMS (EI)
m/z: [M]+ calcd. for C15H16OS: 244.0922; found: 244.0917.
4-(1-phenylethyl)phenol (3o).18 The title compound was
prepared according to the general procedure and purified by
column chromatography on silica gel and eluted with petrole-
um ether/ethyl acetate (5/1) to afford a colorless oil in 52%
1
yield (41.2 mg). H NMR (400 MHz, CDCl3): δ 7.28 – 7.24
(m, 2H), 7.19 – 7.14 (m, 3H), 7.05 (d, J = 7.6 Hz, 2H), 6.71 (d,
J = 7.2 Hz, 2H), 5.18 (s, 1H), 4.07 (q, J = 6.8 Hz, 1H), 1.58 (d,
J = 7.2 Hz, 3H); 13C NMR (101 MHz, CDCl3): δ 153.4, 146.7,
138.7, 128.7, 128.3, 127.5, 125.9, 115.1, 43.8, 22.0.
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 6 of 9
1
2
3
2-(1-phenylethyl)phenol (3o’).8a The title compound was
(s, 3H), 1.57 (d, J = 7.2 Hz, 3H); 13C NMR (101 MHz, CDCl3):
4
5
6
7
8
9
prepared according to the general procedure and purified by
column chromatography on silica gel and eluted with petrole-
um ether/ethyl acetate (5/1) to afford a colorless oil in 32%
yield (25.3 mg). 1H NMR (400 MHz, CDCl3) δ 7.18 – 7.09 (m,
6H), 7.02 – 6.98 (m, 1H), 6.85 – 6.83 (m, 1H), 6.60 (d, J = 8.0
Hz, 1H), 4.73 (s, 1H), 4.42 – 4.06 (m, 1H), 1.52 (d, J = 7.2 Hz,
3H); 13C NMR (101 MHz, CDCl3): δ 153.2, 145.3, 131.9,
128.6, 127.9, 127.5, 127.4, 126.4, 120.8, 115.9, 38.6, 21.0.
δ 146.8, 146.1, 144.9, 138.6, 132.7, 128.1, 127.5, 125.7, 117.5,
106.1, 60.4, 56.1, 37.7, 21.6. HRMS (EI) m/z: [M]+ calcd. for
C16H18O3: 258.1256; found: 258.1250.
2-(1-phenylethyl)benzene-1,4-diol (3u).19 The title com-
pound was prepared according to the general procedure and
purified by column chromatography on silica gel and eluted
with petroleum ether/ethyl acetate (5/1) to afford a colorless
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
1
oil in 80% yield (68.5 mg). H NMR (400 MHz, CDCl3): δ
3,5–dimethyl–2–(1–phenylethyl)phenol (3p). The title
compound was prepared according to the general procedure
and purified by column chromatography on silica gel and elut-
ed with petroleum ether/ethyl acetate (5/1) to afford a color-
7.29 – 7.17 (m, 5H), 6.70 (s, 1H), 6.61 – 6.53 (m, 2H), 5.09 (s,
1H), 4.64 (s, 1H), 4.32 (q, J = 7.2 Hz, 1H), 1.56 (d, J = 7.2 Hz,
3H); 13C NMR (101 MHz, CDCl3): δ 149.5, 147.0, 145.1,
133.6, 128.6, 127.5, 126.4, 116.9, 114.9, 113.7, 38.6, 20.9.
1
less oil in 86% yield (77.7 mg). H NMR (400 MHz, CDCl3):
1–(1–(o–tolyl)ethyl)naphthalen–2–ol (3v). The title com-
pound was prepared according to the general procedure and
purified by column chromatography on silica gel and eluted
with petroleum ether/dichloromethane (1/1) to afford a color-
δ 7.30 – 7.27 (m, 4H), 7.20 – 7.19 (m, 1H), 6.60 (s, 1H), 6.39
(s, 1H), 4.57 – 4.54 (m, 2H), 2.31 (s, 3H), 2.20 (s, 3H), 1.64 (d,
J = 7.2 Hz, 3H); 13C NMR (101 MHz, CDCl3): δ 154.0, 143.9,
137.0, 136.8, 128.7, 127.9, 126.9, 126.4, 123.9, 115.8, 36.0,
20.8, 20.5, 16.8. HRMS (EI) m/z: [M]+ calcd. for C16H18O:
226.1358; found: 226.1352.
1
less oil in 94% yield (98.5 mg). H NMR (400 MHz, CDCl3):
δ 8.17 (d, J = 8.4 Hz, 1H), 7.79 (d, J = 8.0 Hz, 1H), 7.75 (d, J
= 7.6 Hz, 1H), 7.63 (d, J = 8.8 Hz, 1H), 7.54 (t, J = 7.2 Hz,
1H) 7.40 – 7.34 (m, 2H), 7.26 – 7.16 (m, 2H) , 6.92 (d, J = 8.8
Hz, 1H), 5.25 (s, 1H), 5.06 (q, J = 6.8 Hz, 1H), 1.91 (s, 3H),
1.78 (d, J = 7.2 Hz, 3H); 13C NMR (101 MHz, CDCl3): δ
151.9, 141.5, 138.6, 132.5, 131.7, 129.6, 129.1, 128.7, 127.6,
127.0, 126.0, 125.3, 123.0, 121.8, 121.3, 119.6, 34.5, 19.9,
18.2. HRMS (EI) m/z: [M]+ calcd. for C19H18O: 262.1358;
found: 262.1354.
2–methyl–4–(1–phenylethyl)phenol (3q).7d The title com-
pound was prepared according to the general procedure and
purified by column chromatography on silica gel and eluted
with petroleum ether/ethyl acetate (5/1) to afford a colorless
1
oil in 84% yield (71.2 mg). H NMR (400 MHz, CDCl3): δ
7.20 – 7.17 (m, 2H), 7.13 – 7.08 (m, 3H), 6.87 (s, 1H), 6.83 (d,
J = 8.0 Hz, 1H), 6.57 (d, J = 8.4 Hz, 1H), 4.78 (s, 1H), 3.96 (q,
J = 6.4 Hz, 1H), 2.10 (s, 3H), 1.50 (d, J = 7.2 Hz, 3H); 13C
NMR (101 MHz, CDCl3): δ 151.9, 146.8, 138.6, 130.2, 128.3,
127.5, 126.0, 125.9, 123.6, 114.7, 43.9, 22.0, 15.9.
6-(1-phenylethyl)benzo[d][1,3]dioxol-5-ol (3r).20 The title
compound was prepared according to the general procedure
and purified by column chromatography on silica gel and elut-
ed with petroleum ether/ ethyl acetate (5/1) to afford a color-
less oil in 96% yield (92.9 mg). 1H NMR (400 MHz, CDCl3) δ
7.38 – 7.11 (m, 5H), 6.73 (s, 1H), 6.36 (s, 1H), 5.88 (d, J = 2.6
Hz, 2H), 4.45 (s, 1H), 4.27 (q, J = 7.2 Hz, 1H), 1.57 (d, J = 7.2
Hz, 3H). 13C NMR (101 MHz, CDCl3): δ 147.7, 146.2, 145.3,
141.6, 128.7, 127.3, 126.5, 124.2, 107.3, 101.0, 98.8, 38.5,
21.2.
1–(1–(m–tolyl)ethyl)naphthalen–2–ol (3w). The title com-
pound was prepared according to the general procedure and
purified by column chromatography on silica gel and eluted
with petroleum ether/dichloromethane (1/1) to afford a color-
1
less oil in 86% yield (90.1 mg). H NMR (400 MHz, CDCl3):
8.07 (d, J = 8.4 Hz, 1H), 7.80 (d, J = 8.0 Hz, 1H), 7.67 (d, J =
8.8 Hz, 1H), 7.48 (t, J = 7.6 Hz, 1H), 7.37 – 7.33 (m, 1H),
7.26 – 7.19 (m, 3H), 7.08 – 7.07 (m, 1H), 7.00 (d, J = 8.8 Hz,
1H), 5.13 (q, J = 7.2 Hz, 1H), 4.98 (s, 1H), 2.30 (s, 3H), 1.75
(d, J = 7.2 Hz, 3H); 13C NMR (101 MHz, CDCl3): δ 151.6,
143.4, 138.9, 132.8, 129.6, 129.0, 128.8, 128.6, 128.0, 127.7,
126.6, 124.0, 123.8, 123.1, 122.5, 119.5, 34.8, 21.5, 17.0.
HRMS (EI) m/z: [M]+ calcd. for C19H18O: 262.1358; found:
262.1352.
5-(tert-butyl)-2-(1-phenylethyl)phenol (3s). The title com-
pound was prepared according to the general procedure and
purified by column chromatography on silica gel and eluted
with petroleum ether/ethyl acetate (10/1) to afford a colorless
1–(1–(p–tolyl)ethyl)naphthalen–2–ol (3x).16 The title com-
pound was prepared according to the general procedure and
purified by column chromatography on silica gel and eluted
with petroleum ether/dichloromethane (1/1) to afford a color-
1
oil in 95% yield (96.5 mg). H NMR (400 MHz, CDCl3): δ
1
7.32 – 7.23 (m, 4H), 7.20 (d, J = 6.7 Hz, 1H), 7.16 (d, J = 8.1
Hz, 1H), 6.95 (d, J = 8.1 Hz, 1H), 6.77 (d, J = 1.5 Hz, 1H),
4.60 (dd, J = 8.9, 4.2 Hz, 1H), 4.31 (q, J = 6.9 Hz, 1H), 1.61
(dd, J = 7.3, 0.6 Hz, 3H), 1.28 (d, J = 0.7 Hz, 9H). 13C NMR
(101 MHz, CDCl3): δ 152.9, 151.0, 145.5, 128.7, 127.5, 127.4,
126.4, 117.7, 113.3, 38.6, 34.3, 31.3, 21.1. HRMS (EI) m/z:
[M]+ calcd. for C18H22O: 254.1671; found: 254.1667.
less oil in 91% yield (95.4 mg). H NMR (400 MHz, CDCl3):
δ 8.06 (d, J = 7.6 Hz, 1H), 7.79 (d, J = 6.0 Hz, 1H), 7.65 (d, J
= 8.0 Hz, 1H), 7.48 – 7.45 (m, 1H), 7.35 – 7.27 (m, 3H), 7.14
(d, J = 6.0 Hz, 2H), 6.99 (d, J = 5.6 Hz, 1H), 5.13 – 5.11 (m,
1H), 4.98 (s, 1H), 2.32 (s, 3H), 1.75 (d, J = 7.2 Hz, 3H); 13C
NMR (101 MHz, CDCl3): δ 151.6, 140.3, 136.5, 132.8, 129.8,
129.6, 128.8, 128.6, 127.0, 126.5, 123.9, 123.8, 123.0, 122.5,
122.5, 119.4, 34.5, 21.0, 17.1.
2,6–dimethoxy–3–(1–phenylethyl)phenol (3t). The title
compound was prepared according to the general procedure
and purified by column chromatography on silica gel and elut-
ed with petroleum ether/ethyl acetate (5/1) to afford a color-
1–(1–(4–(tert–butyl)phenyl)ethyl)naphthalen–2–ol (3y).16
The title compound was prepared according to the general
procedure and purified by column chromatography on silica
gel and eluted with petroleum ether/dichloromethane (1/1) to
1
less oil in 82% yield (84.6 mg). H NMR (400 MHz, CDCl3):
1
δ 7.27 – 7.22 (m, 4H), 7.16 – 7.13 (m, 1H), 6.70 – 6.60 (m,
2H), 5.51 (s, 1H), 4.46 (q, J = 7.2 Hz, 1H), 3.86 (s, 3H), 3.65
afford a pale yellow oil in 96% yield (116.7 mg). H NMR
(400 MHz, CDCl3): δ 8.07 (d, J = 8.4 Hz, 1H), 7.80 (d, J =
ACS Paragon Plus Environment

Page 7 of 9
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
1
8.0 Hz, 1H), 7.67 (d, J = 8.8 Hz, 1H), 7.48 (t, J = 7.6 Hz, 1H),
7.38 – 7.31 (m, 5H), 7.00 (d, J = 8.8 Hz, 1H), 5.13 (q, J = 7.2
Hz, 1H), 4.96 (s, 1H), 1.76 (d, J = 7.2 Hz, 3H), 1.30 (s, 9H);
13C NMR (101 MHz, CDCl3): δ 151.7, 149.9, 140.1, 132.9,
129.7, 128.8, 128.6, 126.8, 126.6, 126.1, 123.8, 123.1, 122.5,
119.5, 34.4, 31.3, 17.1.
ford a pale yellow oil in 74% yield (81.7 mg). H NMR (400
MHz, CDCl3): δ 7.36 – 7.04 (m, 2H), 6.93 (t, J = 8.4 Hz, 2H),
6.67 – 6.60 (m, 2H), 5.55 (s, 1H), 4.43 (q, J = 7.2 Hz, 1H),
3.84 (s, 3H), 3.65 (s, 3H), 1.54 (d, J = 7.2 Hz, 3H). 13C NMR
(101 MHz, CDCl3): δ 161.0 (d, J = 243.4 Hz), 146.2, 144.9,
142.5 (d, J = 3.1 Hz), 138.6, 132.4, 128.8 (d, J = 7.7 Hz),
117.2, 114.8 (d, J = 21.0 Hz), 106.0, 60.3, 56.1, 37.1, 21.7.
HRMS (EI) m/z: [M]+ calcd. for C16H17FO3: 276.1162; found:
276.1168.
1–(1–(4–fluorophenyl)ethyl)naphthalen–2–ol (3z). The ti-
tle compound was prepared according to the general procedure
and purified by column chromatography on silica gel and elut-
ed with petroleum ether/dichloromethane (1/1) to afford a pale
yellow oil in 90% yield (95.8 mg). 1H NMR (400 MHz,
CDCl3): δ 7.97 (d, J = 7.2 Hz, 1H), 7.79 (d, J = 8.0 Hz, 1H),
7.66 (d, J = 8.8 Hz, 1H), 7.436 (t, J = 6.8 Hz, 1H), 7.35 – 7.20
(m, 3H), 7.01 – 6.99 (m, 3H), 5.14 – 5.12 (m, 1H), 4.93 (s,
1H), 1.78 (d, J = 7.2 Hz, 3H); 13C NMR (101 MHz, CDCl3): δ
161.5 (d, JC-F = 235.6 Hz), 151.3, 139.7 (d, JC-F = 3.2 Hz),
132.7, 129.7, 128.9, 128.8, 128.6 (d, JC-F = 7.9 Hz), 126.5,
123.5, 123.1, 122.8, 119.1, 115.5 (d, JC-F = 21.0 Hz), HRMS
(EI) m/z: [M]+ calcd. for C18H15FO: 266.1107; found:
266.1102.
1–(1–(4–chlorophenyl)ethyl)naphthalen–2–ol (3za).16 The
title compound was prepared according to the general proce-
dure and purified by column chromatography on silica gel and
eluted with petroleum ether/dichloromethane (1/1) to afford a
brown oil in 60% yield (67.7 mg). 1H NMR (400 MHz,
CDCl3): δ 7.93 (d, J = 8.4 Hz, 1H), 7.78 (d, J = 8.0 Hz, 1H),
7.66 (d, J = 8.8 Hz, 1H), 7.42 (t, J = 7.2 Hz, 1H), 7.32 (t, J =
7.6 Hz, 1H), 7.26 – 7.23 (m, 4H), 6.99 (d, J = 8.8 Hz, 1H),
5.12 (q, J = 7.2 Hz, 1H), 4.86 (s, 1H), 1.78 (d, J = 7.2 Hz, 3H);
13C NMR (101 MHz, CDCl3): δ 151.2, 142.8, 132.7, 132.1,
129.8, 128.9, 128.8, 128.8, 128.5, 126.6, 123.40, 123.2, 122.9,
118.9, 34.3, 17.3.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
2,6–dimethoxy–3–(1–(naphthalen–2–yl)ethyl)phenol (3ze).
The title compound was prepared according to the general
procedure and purified by column chromatography on silica
gel and eluted with petroleum ether/ethyl acetate (5/1) to af-
1
ford a pale yellow oil in 72% yield (88.7 mg). H NMR (400
MHz, CDCl3): δ 7.78 – 7.68 (m, 4H), 7.45 – 7.33 (m, 3H),
6.70 – 6.60 (m, 2H), 5.52 (s, 1H), 4.63 (q, J = 6.8 Hz, 1H),
3.85 (s, 3H), 3.67 (s, 3H), 1.66 (d, J = 7.2 Hz, 3H); 13C NMR
(101 MHz, CDCl3): δ 146.2, 145.0, 144.2, 138.6, 133.5, 132.5,
132.0, 127.7, 127.5, 127.0, 125.8, 125.1, 117.7, 106.2, 60.5,
56.2, 37.7, 21.5. HRMS (EI) m/z: [M]+ calcd. for C20H20O3:
308.1412; found: 308.1417.
2,6-dimethoxy-3-(1-(thiophen-2-yl)ethyl)phenol (3zf). The
title compound was prepared according to the general proce-
dure and purified by column chromatography on silica gel and
eluted with petroleum ether/ethyl acetate (5/1) to afford a pale
yellow oil in 62% yield (65.5 mg). 1H NMR (400 MHz,
CDCl3): 7.11 – 7.10 (m, 1H), 6.90 (s, 1H), 6.81 (s, 1H), 6.71 –
6.61 (m, 2H), 4.70 (q, J = 6.8 Hz, 1H), 3.86 (s, 3H), 3.81 (s,
3H), 1.64 (d, J = 7.2 Hz, 3H); 13C NMR (101 MHz, CDCl3): δ
151.3, 146.2, 144.6, 138.4, 132.4, 126.4, 123.4, 123.1, 117.5,
106.4, 60.8, 56.1, 33.2, 23.0. HRMS (EI) m/z: [M]+ calcd. for
C14H16O3S: 264.0820; found: 264.0824.
2,6-dimethoxy-3-(1-(p-tolyl)ethyl)phenol (3zb). The title
compound was prepared according to the general procedure
and purified by column chromatography on silica gel and elut-
ed with petroleum ether/ethyl acetate (5/1) to afford a pale
yellow oil in 93% yield (101.2 mg). 1H NMR (400 MHz,
CDCl3): δ 7.13 – 7.05 (m, 4H), 6.69 – 6.59 (m, 2H), 5.50 (s,
1H), 4.43 (q, J = 7.2 Hz, 1H), 3.85 (s, 3H), 3.68 (s, 3H), 2.29
(s, 3H), 1.55 (d, J = 7.2 Hz, 3H); 13C NMR (101 MHz, CDCl3):
δ 146.0, 144.9, 143.8, 138.5, 135.1, 132.9, 128.8, 127.4, 117.5,
106.2, 60.5, 56.1, 37.2, 21.7, 20.9. HRMS (EI) m/z: [M]+
calcd. for C17H20O3: 272.1412; found:272.1410.
2,6–dimethoxy-3–(2,3–dihydro–1H–inden–1–yl)–phenol
(3zg). The title compound was prepared according to the gen-
eral procedure and purified by column chromatography on
silica gel and eluted with petroleum ether/ethyl acetate (5/1) to
1
afford a brown oil in 73% yield (78.8 mg). H NMR (400
MHz, CDCl3): δ 7.26 (d, J = 7.2 Hz, 1H), 7.17 – 7.08 (m, 2H),
6.95 (d, J = 7.2 Hz, 1H), 6.56 – 6.43 (m, 2H), 5.69 (s, 1H),
4.67 (t, J = 8.4 Hz, 1H), 3.85 (s, 3H), 3.81 (s, 3H), 3.06 – 2.89
(m, 2H), 2.58 – 2.53 (m, 1H), 2.04 – 1.94 (m, 1H); 13C NMR
(101 MHz, CDCl3): 146.9, 146.0, 145.6, 144.3, 138.3, 131.6,
126.2, 126.1, 124.6, 124.1, 118.2, 106.6, 60.9, 56.1, 44.1, 35.8,
31.7. HRMS (EI) m/z: [M]+ calcd. for C17H18O3: 270.1256;
found: 270.1250.
1,3,5-trimethoxy-2-(1-phenylethyl)benzene (3zh).18 The ti-
tle compound was prepared according to the general procedure
and purified by column chromatography on silica gel and elut-
ed with petroleum ether/dichloromethane (2/1) to afford a
white solid in 77% yield (83.8 mg). 1H NMR (400 MHz,
CDCl3): δ 7.28 – 7.19 (m, 4H), 7.11 – 7.07 (m, 1H), 6.12 (s,
2H), 4.74 (q, J = 7.2 Hz, 1H), 3.78 (s, 3H), 3.68 (s, 6H), 1.63
(d, J = 7.6 Hz, 3H); 13C NMR (101 MHz, CDCl3): 159.4,
159.0, 146.6, 127.5, 127.2, 124.8, 115.9, 91.4, 55.7, 55.2, 32.9,
17.7.
2,6-dimethoxy-3-(1-(4-(tert-butyl)phenyl)ethyl)-phenol
(3zc). The title compound was prepared according to the gen-
eral procedure and purified by column chromatography on
silica gel and eluted with petroleum ether/ethyl acetate (5/1) to
1
afford a pale yellow oil in 87% yield (109.3 mg). H NMR
(400 MHz, CDCl3): δ 7.28 – 7.16 (m, 4H), 7.69 – 6.59 (m,
2H), 5.53 (s, 1H), 4.44 (q, J = 6.8 Hz, 1H), 3.84 (s, 3H), 3.69
(s, 3H), 1.56 (d, J = 7.2 Hz, 3H), 1.28 (s, 9H); 13C NMR (101
MHz, CDCl3): δ 148.4, 146.0, 144.9, 143.5, 138.5, 133.0,
127.1, 125.0, 117.5, 106.2, 60.4, 56.1, 37.0, 34.3, 31.4, 21.6.
HRMS (EI) m/z: [M]+ calcd. for C20H26O3: 314.1882; found:
314.1886.
2,6-dimethoxy-3-(1-(4-fluorophenyl)ethyl)-phenol (3zd).
The title compound was prepared according to the general
procedure and purified by column chromatography on silica
gel and eluted with petroleum ether/ethyl acetate (5/1) to af-
1-methoxy-4-(1-phenylethyl)benzene (3zi).7d The title com-
pound was prepared according to the general procedure and
purified by column chromatography on silica gel and eluted
with petroleum ether to afford a colorless oil in 31% yield
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 8 of 9
1
2
3
(26.3 mg). 1H NMR (400 MHz, CDCl3): δ 7.26 (d, J = 8.4 Hz,
We thank the National Natural Science Foundation (NSF) of
China (grant nos. 21878072, 21706058, and 21573065) and
the NSF of Hunan Province (grant nos. 2018JJ3031 and
2016JJ1007) for financial support.
4
5
6
7
8
9
2H), 7.21 – 7.12 (m, 5H), 6.82 (d, J = 8.0 Hz, 2H), 4.10 (q, J =
7.2 Hz, 1H), 3.77 (s, 3H), 1.61 (d, J = 7.2 Hz, 3H); 13C NMR
(101 MHz, CDCl3): δ 157.8, 146.8, 138.5, 128.5, 128.3, 127.5,
125.9, 113.7, 55.2, 43.9, 22.0.
References
2-methoxy-1-(1-phenylethyl)naphthalene (3zj). The title
compound was prepared according to the general procedure
and purified by column chromatography on silica gel and elut-
ed with petroleum ether to afford a colorless oil in 40% yield
(41.9 mg). 1H NMR (400 MHz, CDCl3): δ 7.78 – 7.76 (m, 1H),
7.70 – 7.67 (m, 2H), 7.24 – 7.13 (m, 7H), 7.07 – 7.03 (m, 1H),
5.20 (q, J = 7.2 Hz, 1H), 3.70 (s, 3H), 1.74 (d, J = 7.2 Hz, 3H);
13C NMR (101 MHz, CDCl3): δ 154.9, 146.0, 132.5, 130.0,
128.7, 128.4, 128.1, 127.9, 127.0, 125.9, 125.1, 124.4, 123.1,
114.7, 56.8, 34.5, 18.0. HRMS (EI) m/z: [M]+ calcd. for
C19H18O: 262.1358; found: 262.1353.
(1) (a) Akiyama, T. Stronger Brønsted Acids. Chem. Rev. 2007,
107, 5744. (b) Rueping, M.; Kuenkel, A.; Atodiresei, I. Chiral
Brønsted Acids in Enantioselective Carbonyl Activations-Activation
Modes and Applications. Chem. Soc. Rev. 2011, 40, 4539. (c) Wang,
Y.; Zheng, S.; Hu, Y.; Tan, B. Brønsted Acid-catalysed Enantioselec-
tive Construction of Axially Chiral Arylquinazolinones. Nat. Com-
mun. 2017, 8, 15489.
(2) (a) Xu, G.; Wang, L.; Li, M.; Tao, M.; Zhang, W. Phosphorous
Acid Functionalized Polyacrylonitrile Fibers with a Polarity Tunable
Surface Micro-environment for One-pot C–C and C–N Bond For-
mation Reactions. Green Chem. 2017, 19, 5818. (b) Rockwell, N. M.
Phosphorous Acid Catalyzed Phenol Esterification. U.S. Patent Appl.
US 4610825, 1986. (c) Redmore, D. Chemistry of Phosphorous Acid:
New Routes to Phosphonic Acids and Phosphate Esters. J. Org. Chem.
1978, 43, 992. (d) Blazis, V. J.; Koeller, K. J.; Spilling, C. D. Reac-
tions of Chiral Phosphorous Acid Diamides: The Asymmetric Synthe-
sis of Chiral. alpha.-Hydroxy Phosphonamides, Phosphonates, and
Phosphonic Acids. J. Org. Chem. 1995, 60, 931. (e) Reetz, M. T.;
Bondarev, O. Mixtures of Chiral Phosphorous Acid Diesters and
Achiral P Ligands in the Enantio- and Diastereoselective Hydrogena-
tion of Ketimines. Angew. Chem., Int. Ed. 2007, 46, 4523.
(3) (a) Li, Z.; Dong, J.; Chen, X.; Li, Q.; Zhou, Y.; Yin, S.-F. Met-
al- and Oxidant-Free Synthesis of Quinazolinones from β-Ketoesters
with o-Aminobenzamides via Phosphorous Acid-Catalyzed Cy-
clocondensation and Selective C–C Bond Cleavage. J. Org. Chem.
2015, 80, 9392. (b) Zhou, Y.; Li, Z.; Yang, X.; Chen, X.; Li, M.;
Chen, T.; Yin, S.-F. Phosphorous Acid Promoted Hydration-
Condensation of Aromatic Alkynes with Aldehydes Affording Chal-
cones in an Oil/Water Two-phase System. Synthesis 2016, 48, 231. (c)
Gan, X.; Fu, Z.; Liu, L.; Yan, Y.; Chen, C.; Zhou, Y.; Dong, J. Phos-
phorous Acid Promoted Isomerization of Propargyl Alcohols to α, β-
unsaturated Carbonyl Compounds. Tetrahedron Lett. 2019, 60,
150906.
(4) (a) Davin, L. B.; Jourdes, M.; Patten, A. M.; Kim, K.-W.; Vass
ão, D. G.; Lewis, N. G. Dissection of Lignin Macromolecular Con-
Figuration and Assembly: Comparison to Related Biochemical Pro-
cesses in Allyl/Propenyl Phenol and Lignan Biosynthesis. Nat. Prod.
Rep. 2008, 25, 1015. (b) Fier, P. S.; Maloney, K. M. Direct Conver-
sion of Haloarenes to Phenols under Mild, Transition-Metal-Free
Conditions. Org. Lett. 2016, 18, 2244. (c) Fier, P. S.; Maloney, K. M.
Reagent Design and Ligand Evolution for the Development of a Mild
Copper-Catalyzed Hydroxylation Reaction. Org. Lett. 2017, 19, 3033.
(d) Fier, P. S.; Maloney, K. M. Synthesis of Complex Phenols Ena-
bled by a Rationally Designed Hydroxide Surrogate. Angew. Chem.
2017, 129, 4549; Angew. Chem., Int. Ed. 2017, 56, 4478. (e) Fink-
beiner, H.; Hay, A.; Blanchard, H.; Endres, G. Polymerization by
Oxidative Coupling. The function of Copper in the Oxidation of 2, 6-
Dimethylphenol. J. Org. Chem. 1966, 31, 549. (f) Ge, H. M.; Zhu, C.
H.; Shi, D. H.; Zhang, L. D.; Xie, D. Q.; Yang, J.; Ng, S. W.; Tan, R.
X. Hopeahainol A: An Acetylcholinesterase Inhibitor from Hopea
Hainanensis. Chem. -Eur. J. 2008, 14, 376. (g) Hadj-esfandiari, N.;
Navidpour, L.; Shadnia, H.; Amini, M.; Samadi, N.; Faramarzi, M. A.;
Shafiee, A. Synthesis, Antibacterial Activity, and Quantitative Struc-
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(8R,9S,13S,14S)-3-hydroxy-13-methyl-2-(1-phenylethyl)-
6,7,8,9,11,12,13,14,15,16-decahydro-17H-
cyclopenta[a]phenanthren-17-one (3zk). The title compound
was prepared according to the general procedure and purified
by column chromatography on silica gel and eluted with petro-
leum ether/dichloromethane (1/1) to afford a pale yellow oil in
1
59% yield (88.3 mg). H NMR (400 MHz, CDCl3): δ 7.46 –
6.73 (m, 6H), 6.42 (s, 1H), 5.09 (m, 1H), 4.29 (s, 1H), 2.74 (s,
2H), 2.52 – 1.72 (m, 8H), 1.54 – 1.33 (m, 8H), 0.82 (s, 3H);
13C NMR (101 MHz, CDCl3): δ 221.6, 151.3, 145.7, 135.5,
131.6, 129.6, 128.5, 127.4, 126.1, 124.9, 115.9, 50.3, 48.1,
44.1, 38.4, 35.9, 31.5, 29.0, 26.5, 26.0, 21.5, 21.0, 13.8.
HRMS (EI) m/z: [M]+ calcd. for C26H30O2: 374.2246; found:
374.2240.
4-(4-hydroxy-3-(1-phenylethyl)phenyl)butan-2-one (3zl).
The title compound was prepared according to the general
procedure and purified by column chromatography on silica
gel and eluted with petroleum ether/dichloromethane (1/1) to
afford a pale yellow oil in 72% yield (77.2 mg). 1H NMR (400
MHz, CDCl3): δ 7.32 – 7.16 (m, 5H), 7.03 (s, 1H), 6.91 (d, J =
8.1 Hz, 1H), 6.66 (d, J = 8.1 Hz, 1H), 4.73 (s, 1H), 4.34 (q, J =
7.1 Hz, 1H), 2.83 (t, J = 7.5 Hz, 2H), 2.72 (t, J = 7.5 Hz, 2H),
2.12 (s, 3H), 1.61 (d, J = 7.3 Hz, 3H); 13C NMR (101 MHz,
CDCl3): δ 208.5, 151.7, 145.3, 133.1, 132.0, 128.6, 127.8,
127.5, 127.0, 126.4, 116.0, 45.5, 38.7, 30.1, 29.2, 20.9. HRMS
(EI) m/z: [M]+ calcd. for C18H20O2: 268.1463; found: 268.1458.
Associated Content
Supporting Information
Copies of 1H and 13C spectroscopies. This material is available
free of charge via the Internet at http://pubs.acs.org.
Author Information
Corresponding Author
*E-mail: zhouyb@hnu.edu.cn.
ORCID
ture-Activity
Relationships
of
New
(Z)-2-
Jianyu Dong: 0000-0003-2161-1372
Yongbo Zhou: 0000-0002-3540-8618
(Nitroimidazolylmethylene)-3 (2H)-Benzofuranone Derivatives.
Bioorg. Med. Chem. Lett. 2007, 17, 6354. (h) Kwon, Y.-J.; Sohn, M.-
J.; Zheng, C.-J.; Kim, W.-G. Fumimycin: A Peptide Deformylase
Inhibitor with an Unusual Skeleton Produced by Aspergillus
Fumisynnematus. Org. Lett. 2007, 9, 2449.
Notes
The authors declare no competing financial interest.
(5) (a) Liu, L.; Ji, X.; Dong, J.; Zhou, Y.; Yin, S.-F. Metal-Free
Oxidative Annulation of 2-Naphthols with Terminal Alkynes Afford-
Acknowledgment
ACS Paragon Plus Environment

Page 9 of 9
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
ing 2-Arylnaphtho [2,1-b] furans. Org. Lett. 2016, 18, 3138. (b) Liu,
Tetrahedron Lett. 2012, 53, 1485. (d) Vinu, A.; Devassy, B. M.; Hal-
ligudi, S. B.; Böhlmann, W.; Hartmann, M. Highly Active and Selec-
tive AlSBA-15 Catalysts for the Vapor Phase tert-Butylation of Phe-
nol. Appl. Catal. A: Gen. 2005, 281, 207.
(12) Rueping, M.; Bootwicha, T.; Sugiono, E. Efficient and Gen-
eral Continuous-Flow Hydroarylation and Hydroalkylation of Sty-
renes. Adv. Synth. Catal. 2010, 352, 2961.
(13) Carrión, M. C.; Cole-Hamilton, D. J. Halide-Free Ethylation
of Phenol by Multifunctional Catalysis Using Phosphinite Ligands.
Chem. Commun. 2006, 42, 4527.
(14) Dorta, R.; Togni, A. Addition of the ortho-C−H Bonds of
Phenol across an Olefin Catalysed by a Chiral Iridium (I) Diphos-
phine Complex. Chem. Commun. 2003, 39, 760.
(15) Kuninobu, Y.; Matsuki, T.; Takai, K. Rhenium-Catalyzed Re-
gioselective Alkylation of Phenols. J. Am. Chem. Soc. 2009, 131,
9914.
(16) Patil, R. D.; Joshi, G.; Adimurthy, S. KHSO4: A Highly Effi-
cient and Reusable Heterogeneous Catalyst for Hydroarylation of
Styrenes. Monatshefte fnatChemie-Chemical Monthly 2010, 141,
1093.
(17) Dada, R.; Singh, G.; Pareek, A.; Kausar, S.; Yaragorla, S. Mi-
crowave Assisted Benzylation of Naphthols and 4-Hydroxycoumarin
Under Catalyst & Solvent Free Conditions. Tetrahedron Lett. 2016,
57, 3739.
(18) Li, X.; Feng, Y.; Lin, L.; Zou, G. Synthesis of Diarylmethanes
via Metal-Free Reductive Cross-Coupling of Diarylborinic Acids with
Tosyl Hydrazones. J. Org. Chem. 2012, 77, 10991.
L.; Qian, L.-W.; Wu, S.; Dong, J.; Xu, Q.; Zhou, Y.; Yin, S.-F. Selec-
tive Aerobic C–H Amination of Phenols with Primary Amines over
Copper toward Benzoxazoles. Org. Lett. 2017, 19, 2849. (c) Ciufolini,
M. A.; Braun, N. A.; Canesi, S.; Ousmer, M.; Chang, J.; Chai, D.
Oxidative Amidation of Phenols through the Use of Hypervalent
Iodine Reagents: Development and Applications. Synthesis 2007,
2007, 3759. (d) Huang, Z.; Lumb, J.-P. Phenol-Directed C−H Func-
tionalization. ACS Catal. 2018, 9, 521. (e) Liu, Q.; Jackstell, R.; Bel-
ler, M. Oxidative Catalytic Coupling Reactions: Selective Formation
of C–C and C–X Bonds Using Radical Processes. Angew. Chem., Int.
Ed. 2013, 52, 13871. (f) Yu, D. G.; de Azambuja, F.; Glorius, F. Di-
rect Functionalization with Complete and Switchable Positional Con-
trol: Free Phenol as a Role Model. Angew. Chem., Int. Ed. 2014, 53,
7710.
(6) (a) Mahindaratne, M. P.; Wimalasena, K. Detailed Characteri-
zation of p-Toluenesulfonic Acid Monohydrate as a Convenient,
Recoverable, Safe, and Selective Catalyst for Alkylation of the Aro-
matic nucleus. J. Org. Chem. 1998, 63, 2858. (b) Olah, G. A. Friedel-
Crafts and Related Reactions. 1963. (c) Evano, G.; Theunissen, C.
Beyond Friedel and Crafts: Innate Alkylation of C−H Bonds in
Arenes. Angew. Chem. 2019, 131,7278; Angew. Chem., Int. Ed. 2019,
58, 7202. (d) Evano, G.; Theunissen, C. Beyond Friedel and Crafts:
Innate Alkylation of C−H Bonds in Arenes. Angew. Chem. 2019,
131,7638; Angew. Chem., Int. Ed. 2019, 58, 7558. (e) Rueping, M.;
Nachtsheim, B. J. A Review of New Developments in the Friedel-
Crafts Alkylation-From Green Chemistry to Asymmetric Catalysis.
Beilstein J. Org. Chem. 2010, 6, 6.
(7) (a) Babu, K. R.; Chen, S.; Li, Y.; Bao, H. Iron Catalyzed Oxi-
dative Hydroarylation, Methylarylation, and Diarylation of Vi-
nylarenes to Generate Unsymmetrical 1,1-Diarylalkanes. Chin. J. Org.
Chem. 2017, 37, 1160. (b) Duan, S.; Jana, R.; Tunge, J. A. Lewis
Acid-Catalyzed Diastereoselective Hydroarylation of Benzylidene
Malonic Esters. J. Org. Chem. 2009, 74, 4612. (c) Kischel, J.; Jovel,
I.; Mertins, K.; Zapf, A.; Beller, M. A Convenient FeCl3-Catalyzed
Hydroarylation of Styrenes. Org. Lett. 2006, 8, 19. (d) Lee, S. Y.;
Villani-Gale, A.; Eichman, C. C. Room Temperature Catalyst System
for the Hydroarylation of Olefins. Org. Lett. 2016, 18, 5034. (e)
Rueping, M.; Nachtsheim, B. J.; Scheidt, T. Efficient Metal-
Catalyzed Hydroarylation of Styrenes. Org. Lett. 2006, 8, 3717. (f)
Yadav, J.; Reddy, B.; Sengupta, S.; Biswas, S. Gallium (III) Chloride
Catalyzed Hydroarylation of Arylacetylenes with Naphthols and Phe-
nols: A Facile Synthesis of Vinylarenes. Synthesis 2009, 1301. (g)
Buu-HoÏ, N. P.; Bihan, H. L.; Binon, F. Condensation of Phenols and
Naphthols with Styrene. J. Org. Chem. 1952, 17, 243.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(19) Kumli, E.; Montermini, F.; Renaud, P. Radical Addition to 1,
4-Benzoquinones: Addition at O-versus C-atom. Org. Lett. 2006, 8,
5861.
(20) Jurd, L.; Fye, R. L.; Morgan Jr, J. New Types of Insect Che-
mosterilants. Benzylphenols and Benzyl-1,3-benzodioxole Deriva-
tives as Additives to Housefly Diet. J. Agríe. Food Chem. 1979, 27,
1007.
(8) Hu, F.; Patel, M.; Luo, F.; Flach, C.; Mendelsohn, R.; Gar-
funkel, E.; He, H.; Szostak, M. Graphene-Catalyzed Direct Friedel-
Crafts Alkylation Reactions: Mechanism, Selectivity, and Synthetic
Utility. J. Am. Chem. Soc. 2015, 137, 14473.
(9) (a) Botteghi, C.; Corrias, T.; Marchetti, M.; Paganelli, S.; Pic-
colo, O. A New Efficient Route to Tolterodine. Org. Process Res.
Dev. 2002, 6, 379. (b) Tschesche, R.; Delhvi, M. S.; Sepúlveda-Boza,
S.; Zilliken, F.; Kirfel, A.; Will, G. Haplopappin, ein 8-(α-
Methylbenzyl) Flavonoid aus Haplopapus Foliosus. Liebigs Ann.
Chem. 1985, 1985, 2465.
(10) Mohan, D. C.; Patil, R. D.; Adimurthy, S. H-β-Zeolite-
Catalysed Hydroarylation of Styrenes. Eur. J. Org. Chem. 2012, 2012,
3520.
(11) (a) Haldar, S.; Koner, S. Iron-Containing Mesoporous Alumi-
nosilicate: A Highly Active and Reusable Heterogeneous Catalyst for
Hydroarylation of Styrenes. J. Org. Chem. 2010, 75, 6005. (b) Mohan
Reddy, K.; Seshu Babu, N.; Sai Prasad, P. S.; Lingaiah, N. Alumini-
um-Exchanged Tungstophosphoric acid: An Efficient Catalyst for
Intermolecular Hydroarylation of Vinyl Arenes. Catal. Commun.
2008, 9, 2525. (c) Varghese, S.; Nagarajan, S.; Benzigar, M. R.;
Mano, A.; Alothman, Z. A.; Raj, G. A. G.; Vinu, A. 3D Nanoporous
FeAl-KIT-5 with a Cage Type Pore Structure: A Highly Efficient and
Stable Catalyst for Hydroarylation of Styrene and Arylacetylenes.
ACS Paragon Plus Environment