Regioselective oxyalkylation of vinylarenes catalyzed by diatomite-supported manganese oxide nanoparticles

Article abstract of DOI:10.1021/jo2026367

A regioselective oxyalkylation reaction of vinylarenes with cyclic ethers was developed under the catalysis of a new heterogeneous catalyst, the diatomite-supported Mn₃O₄ nanoparticles (SMONP-1). The use of this heterogeneous catalyst provided a novel approach for the synthesis of α-carbonyled β-alkylated aryl derivatives via a sp³ C-H bond functionalization under mild aerobic conditions.

Full text of DOI:10.1021/jo2026367

Note
pubs.acs.org/joc
Regioselective Oxyalkylation of Vinylarenes Catalyzed by
Diatomite-Supported Manganese Oxide Nanoparticles
Huayin Sun, Yonghui Zhang, Fengfeng Guo, Zhenggen Zha,* and Zhiyong Wang*
Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Soft Matter Chemistry and Department
of Chemistry, University of Science and Technology of China, Hefei, 230026, P. R. China
S
* Supporting Information
ABSTRACT: A regioselective oxyalkylation reaction of vinylarenes with
cyclic ethers was developed under the catalysis of a new heterogeneous
catalyst, the diatomite-supported Mn3O4 nanoparticles (SMONP-1). The use
of this heterogeneous catalyst provided a novel approach for the synthesis of
α-carbonyled β-alkylated aryl derivatives via a sp3 C−H bond functionalization
under mild aerobic conditions.
ransition-metal-catalyzed C−H bond functionalization has
SMONP-2, SMONP-3, and other Mn-based species were
examined as the potential catalysts in the reaction of styrene
with tetrahydrofuran under an air atmosphere. It was found
that SMONPs (SMONP-1, 2, 3) could catalyze this oxida-
tion reaction to afford the corresponding oxyalkylation
product 2a with good yields (Table 1, entries 7−9), whereas
other manganese oxides gave the corresponding product
with lower yields or trace amounts (Table 1, entries 1−4).
Manganese salts, such as MnCl2·4H2O and Mn(OAc)2·4H2O,
failed to give the product (Table 1, entries 5−6). In addi-
tion, the reaction did not work without the catalyst (Table 1,
entry 10).
After screening these SMONPs in detail, the experimental
result indicated that SMONP-1 catalysis could give the best
result (Table 1, entry 7). Subsequently, the reaction was carried
out under different conditions to optimize the reaction
conditions. The reaction was carried out under pure oxygen
atmosphere to give the product 2a with an almost the same
yield (Table 1, entry 11), while the reaction did not work under
nitrogen atmosphere (Table 1, entry 12). It was shown that an
oxidant was necessary for this reaction and air was a suitable
oxidant for this reaction. Afterward, the reaction solvent was
optimized. The other solvents, such as CH3CN, CH2Cl2,
CHCl3, toluene, and DMF, were employed in this reaction, and
it was found that THF was the best solvent to the reaction (see
the Supporting Information). The reaction temperature was
also examined, and it was found that 80 °C was the optimal
temperature (see the Supporting Information). The formation
of C−C bond occurred on the sp3 C−H bond of C2-position
instead of C3-position of tetrahydrofuran. Thus, the optimal
conditions were obtained, that is, SMONP-1 as catalyst, THF
as solvent, and the reaction being performed at 80 °C for 12 h
under air atmosphere.
T
attracted considerable attention, providing an efficient
approach for the assembly of biologically and industrially useful
compounds.1 Difunctionalization of vinylarenes is an important
investigated field of these C−H bond functionalization
reactions.2 Recently, there are many reports for this
transition-metal-catalyzed difunctionalization of vinylarenes,
including dioxygenation,3 diamidation,4 and oxyamidation.5
The C−C bond formation via the intramolecular oxidative
carbofunctionalization of vinylarenes has been broadly studied.6
However, there are few reports on intermolecular metal-
catalyzed oxidative carbofunctionalization of olefins for C−C
bond formation,7 which is still a challenge to the synthetic
chemistry. Recently, metal nanoparticles have been widely used
in organic reactions. They usually display advantages compared
with traditional homogeneous catalysts, such as lower loading,
lower toxicity, and good recyclability. Moreover, the characters
of the supported metal nanoparticles can be displayed by the
characteristics of the supports. To the best of our knowledge,
the intermolecular oxidative carbofunctionalization of olefins
catalyzed by supported metal nanoparticles has not been
reported yet. Our group has been making efforts on nanoparticle-
catalyzed organic reactions.8 Manganese oxide (Mn3O4) nano-
particles (NPs) are often used as a catalyst for the oxidation
reaction.9 Herein, we prepared three heterogeneous catalysts
by encapsulating Mn3O4 NPs on different supports such as
diatomite, ZrO2, and SiO2. The resulting catalysts were employed
in an intermolecular oxyalkylation of vinylarenes. After screening,
it was found that Mn3O4 NPs immobilized on diatomite could
catalyze this reaction to give α-carbonyled β-alkylated aryl deriv-
atives with high regioselectivities and good yields under mild
aerobic conditions.
Initially, Mn3O4 NPs were encapsulated on different
supports, such as diatomite, ZrO2, and SiO2 to give the
corresponding heterogeneous catalysts SMONP-1, SMONP-2,
and SMONP-3, respectively (see the Experimental Section).
The as-synthesized three heterogeneous catalysts were
characterized by TEM, XRD pattern, and ICP atomic emission
(see the Supporting Information). Subsequently, these SMONP-1,
Under the optimized reaction conditions, the scope of
vinylarenes was investigated. As shown in Table 2, a variety of
Received: December 21, 2011
Published: March 5, 2012
© 2012 American Chemical Society
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The Journal of Organic Chemistry
Note
the subsequent α-position oxidation carbonylation of vinyl-
arenes.
Table 1. Oxyalkylation of Styrene with Different Mn
Catalysts
a
From Table 2, no remarkable electronic effect was obviously
observed. Both electron-rich and electron-poor vinylarenes
could efficiently afford the products with good yields.
Substitutions at the ortho position had slight impact on the
yields. For instance, the reaction of p-, m-, and o-
metheylvinylbenzene (1b−1d) afforded 2b, 2c, and 2d with
the yields of 92, 85, and 83%, respectively (Table 2, entries 2−4).
It was noted that good yields were achieved with Cl or Br-
substituted vinylarenes (Table 2, entries 7−10). 2-Vinyl-
naphthalene also led to the corresponding product in good
yield (Table 2, entry 11). Moreover, when tetrahydrofuran was
replaced by 1,4-dioxane, the reaction can be also carried out
smoothly (Table 2, entry 12). To our delight, the terminal
alkenes can be replaced with internal alkenes, and the good
reaction yields can be obtained (Table 2, entries 13−20). When
R1 was methyl or phenyl group, the corresponding products
(2m, 2n, and 2o) were obtained with only syn configuration
(Table 2, entries 13−15). As for the reaction substrates 1p and
1q, the corresponding products 2p and 2q were obtained with
poor diastereoselectivities (Table 2, entries 16−17). On the
other hand, two regioisomers were obtained when 1r, 1s, and
1t were employed respectively as the substrates (Table 2,
entries 18−20). This poor regioselectivity can perhaps be
ascribed to the similarity of R and R1 substituents, which
resulted in a random attack of the THF to the alkene. When the
reaction substrate THF was replaced with 1,3-dioxolane, which
possesses two types of C−H bonds adjacent to the oxygen
atom, the C−H bond cleavage at C2-position of 1,3-dioxolane
preferentially led to yield aryl β-aldehyde protected ketones
(Table 3). It was demonstrated that an excellent regioselec-
tivity for 1,3-dioxolane was achieved under the catalysis of
SMONP-1.
Various substituted alkenes were also employed as the
substrates to react with 1,3-dioxolane, affording C2-oxy-
alkylation ketones with good yields and excellent regioselectiv-
ities to 1,3-dioxolane. In this case, we did not detect the
oxidation products at the C4-position under the reaction
conditions. When both R and R1 were aromatic groups, the
mixture of regioisomers A and B were obtained (Table 3,
entries 16−19). This can be ascribed to the similar reactivity of
the two carbons in the double bond of the alkene.
The recyclability of the catalyst was also investigated with the
model reaction of styrene with tetrahydrofuran. The results are
listed in Table 4. In the fourth round, the reaction yield was
decreased to 83%. The leaching of manganese oxide from the
diatomite may account for the sluggishness of the catalysts. A
measurable amount of manganese (3.88%) was detected in the
mother liquor by ICP atomic emission (see the Supporting
Information). After removal of the SMONP-1, the reaction was
carried out in this mother liquor, and only 3% yield of the
product 2a was obtained. This indicated that SMONP-1 was
the heterogeneous catalyst for this oxyalkylation reaction. The
TEM image of the catalyst after the fourth recycle was similar
to that of the fresh catalyst, as shown in Figure 1b. The XRD
pattern (see the Supporting Information) of SMONP-1 after
the fourth round is similar to that of the fresh SMONP-1.
These results demonstrated that the structure of SMONP-1
almost remained after the recycling reactions.
b
entry
1
catalyst
yield (%)
Mn3O4 nanoparticles
Mn3O4
45
10
9
c
2
3
4
5
6
Mn2O3
MnO2
7
MnCI2·4H2O
Mn(OAc)2·4H2O
SMONP-1
SMONP-2
SMONP-3
d
7
91
59
77
e
8
f
9
10
g
11
h
SMONP-1
SMONP-1
92
12
a
Reaction conditions: styrene (52 mg, 0.5 mmol), 2 mol % Mn
catalyst, THF (2 mL), 80 °C, 12 h under air atmosphere. Isolated
yield. Commercial Mn3O4. 2 mol % (7.0 mg) SMONP-1. 2 mol %
b
c
d
e
f
g
(7.5 mg) SMONP-2. 2 mol % (4.0 mg) SMONP-3. Under O2
h
atmosphere. Under N2 atmosphere.
Table 2. Reaction of Vinylarenes with Tetrahydrofuran
a
Catalyzed by SMONP-1
b
b
entry
R
R1
1
A yield (%)
B yield (%)
1
Ph
H
1a
1b
1c
1d
1e
1f
91
2
4-Me-Ph
3-Me-Ph
2-Me-Ph
4-OMe-Ph
2-OMe-Ph
4-Cl-Ph
2-Cl-Ph
2-Br-Ph
4-Br-Ph
1-naphthyl
Ph
H
92
3
H
85
4
H
83
5
H
90
6
H
84
7
H
1g
1h
1i
82
8
H
80
9
H
84
85
10
11
H
1j
H
1k
1a
1m
1n
1o
1p
1q
1r
79
c
12
H
75
13
14
15
Ph
Me
Me
Me
Me
Ph
Ph
Ph
Ph
80 (100:0)
79 (100:0)
83 (100:0)
79 (59:41)
75 (53:47)
48
2-Br-Ph
4-OMe-Ph
4-Br-Ph
Ph
d
16
d
17
e
18
4-OMe-Ph
2-OMe-Ph
2-Br-Ph
34
44
22
e
19
1s
1t
36
e
20
58
a
Reaction conditions: vinylarenes (0.5 mmol), SMONP-1 (2 mol %,
7.0 mg), THF (2 mL), 80 °C, 12 h under air atmosphere. Isolated
b
c
d
yield. THF was replaced with 1,4-dioxane. The diastereselectivity
e
(syn:anti) was determined by 1H NMR. The products were the
mixture of the two regioisomers.
vinylarenes can be employed in this reaction to give the
products with good yields and regioselectivities via the addition
of the α-sp3 C−H bond adjacent to oxygen to vinylarenes and
To determine the mechanism of the C2-selectivity oxy-
alkylation of vinylarenes, we carried out several control experi-
ments. The reaction did not work under N2 atmosphere
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Note
Table 3. Reaction of Vinylarenes with Dioxolane Catalyzed
by SMONP-1
Scheme 1. Oxidation of I Catalyzed by SMONP-1
a
On the basis of these experiments, we proposed a mechanism
for our oxyalkylation reaction, as depicted in Scheme 2.
b
b
entry
R
R1
1
A yield (%)
B yield (%)
1
Ph
H
1a
1b
1c
1d
1f
84
85
84
79
79
80
76
75
82
73
78
75
77
75
37
55
44
35
76
Scheme 2. Proposed Mechanism for the Reaction
2
4-Me-Ph
3-Me-Ph
2-Me-Ph
2-OMe-Ph
4-Cl-Ph
2-Cl-Ph
2-Br-Ph
4-Br-Ph
1 -naphthyl
Ph
H
3
H
4
H
6
H
7
H
1g
1h
1i
8
H
9
H
10
11
12
13
14
15
H
1j
H
1k
1l
Me
Me
Me
Ph
Ph
Ph
Ph
Ph
Bn
4-OMe-Ph
4-Br-Ph
Ph
1m
1n
1o
1p
1q
1r
1s
1t
c
16
4-Br-Ph
4-OMe-Ph
2-OMe-Ph
2-Br-Ph
Ph
37
24
34
45
c
17
c
18
c
19
20
a
Reaction conditions: vinylarenes (0.5 mmol), SMONP-1 (2 mol %,
7.0 mg), 1,3-dioxolane (2 mL), 80 °C, 12 h under air atmosphere.
Reaction of tetrahydrofuran with O2 catalyzed by SMONP-1
affords tetrahydrofuran free-radical, which reacts with styrene to
produce intermediate 1. Intermediate 1 and O2 then react to
give peroxide 2. Homolytic cleavage of the O−O bond of 2
generates 3, which abstracts a hydrogen atom from THF to
afford intermediate I. Then, I is oxidized by SMONP-1 to
produce ketone.
b
c
Isolated yield. The products were the mixture of the two
regioisomers.
a
Table 4. Recylcing of the Catalyst
In conclusion, a cheap and reusable heterogeneous catalyst
SMONP-1 was prepared and applied to the oxyalkylation of
vinylarenes. In virtue of this SMONP-1, a new synthesis of α-
carbonyl β-alkylated aryl derivatives was developed, and the
corresponding products can be obtained with high regio-
selectivities and good yields. Efforts to apply this heterogeneous
catalyst to other organic reactions are in progress in our laboratory.
run
1
2
3
4
5
yield (%)
91
89
88
85
83
a
Reaction conditions: styrene (0.5 mmol), SMONP-1 (2 mol %,
7.0 mg), THF (2 mL), 80 °C, 12 h.
EXPERIMENTAL SECTION
■
Preparation of Mn3O4 Nanoparticles.10 Mn(OAc)2·4H2O
(0.50 g) and DMSO (30 mL) were added into a 30 mL Teflon-
lined stainless steel autoclave. After Mn(OAc)2·4H2O was dissolved in
DMSO with stirring, the autoclave was sealed. Thermal treatment was
carried out at 120 °C for 6 h, and then the autoclave was cooled to
room temperature. Water was added into the solution, and the
nanoparticles were precipitated after keeping it at room temperature
for 2 h under air. The powder was washed with water and anhydrous
ethanol for 3 times and dried at 60 °C for 6 h in a vacuum. Manganese
oxide nanoparticles were characterized by TEM study (Figure S1,
Supporting Information). Typical XRD pattern of the nanoparticles
are shown in Figure S5 (Supporting Information). All the strong
and shape diffraction peaks are consistent with the reference JCPDS
24−0734, which are indexed to the tetragonal structure of Mn3O4.
Preparation of SMONPs. Mn(OAc)2·4H2O (0.50 g), supports
(0.10 g), hexadecyl trimethyl ammonium bromide (CTAB) (30 mg),
and DMSO (50 mL) were added into a 50 mL Teflon-lined stainless
steel autoclave. After Mn(OAc)2·4H2O was dissolved in DMSO with
stirring, the autoclave was sealed. Thermal treatment was carried out
at 120 °C for 6 h, and then the autoclave was cooled to room
temperature. Water was added into the solution, and the SMONPs
Figure 1. TEM images of (a) fresh SMONP-1 and (b) SMONP-1
after the fourth cycle.
(Table 1, entry 12). Besides, the reaction did not work either
when radical inhibitor TEMPO was added to the system. This
suggested that a free-radical process might be involved in the
reaction. In addition, 1-phenyl-2-(tetrahydrofuran-2-yl)ethanol
(I) was detected in the reaction process by GC−MS analysis
(m/z = 192) (see the Supporting Information), which indicated
that I was the reaction intermediate. We prepared 1-phenyl-
2-(tetrahydrofuran-2-yl)ethanol (I), and this compound can
be oxidized into the product with a yield of 95%, as shown in
Scheme 1.
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Note
were precipitated after keeping it at room temperature for 2 h under
air. The powder was washed with water and anhydrous ethanol for
3 times and dried at 60 °C for 6 h in a vacuum. TEM images of
SMONPs and the average diameters are shown in Figures S2−S4
(Supporting Information). Typical XRD pattern of these nanoparticles
are shown in Figures S6−S12 (Supporting Information).
General Procedure for the Oxyalkylation. SMONP-1 (2 mol %,
7.0 mg) was added into THF solution (2 mL) containing vinylarenes
(0.5 mmol). The mixture was carried out at 80 °C for 12 h under air
atmosphere. After completion of the reaction, the reaction mixture was
centrifuged at ca. 8000 rpm for 6 min. Then, the solution was con-
centrated under a vacuum. The crude product was purified with column
chromatography on silica gel to afford the pure product.
Reuse of the SMONP-1. SMONP-1 (2 mol %, 7.0 mg) was added
into THF solution (2 mL) containing styrene (1 mmol). The mixture
was carried out at 80 °C for 12 h under air atmosphere. The reaction
mixture was centrifuged at ca. 8000 rpm for 6 min. The precipitate was
washed with water and ethanol subsequently and then dried at 60 °C
in a vacuum. The recovered catalyst was reused for the next round.
Oxyalkylation Reaction Catalyzed by the Leaking of
Manganese from SMONP-1. After removal of the SMONP-1, a
measureable amount of manganese (3.88%) was detected in the
mother liquor by ICP atomic emission after the four rounds. The
reaction was carried out in this mother liquor, and only 3% yield of the
product 2a was obtained.
3.14 (q, J = 10.0 Hz, 1 H), 2.17−2.14 (m, 1 H), 1.94−1.87
(m, 1 H), 1.74−1.70 (m, 1 H); 13C NMR (100 MHz, CDCl3) δ 200.5,
158.7, 133.7, 130.6, 120.8, 120.7, 111.7, 75.6, 67.9, 55.7, 50.1, 31.7,
25.8; HRMS calcd for C13H16O3 220.1099, found 220.1102.
1-(4-Chlorophenyl)-2-(tetrahydrofuran-2-yl)ethanone (2g). Yel-
1
low oil: H NMR (400 MHz, CDCl3) δ 7.92−7.89 (m, 2 H), 7.45−
7.42 (m, 2 H), 4.42−4.35 (m, 1 H), 3.91−3.86 (m, 1 H), 3.78−3.72
(m, 1 H), 3.34 (q, J = 10.0 Hz, 1 H), 3.02 (q, J = 10.0 Hz, 1 H), 2.21−
2.16 (m, 1 H), 1.97−1.89 (m, 1 H), 1.61−1.52 (m, 1 H); 13C NMR
(100 MHz, CDCl3) δ 197.4, 139.7, 135.6, 129.8, 129.1, 75.5, 68.0,
44.8, 31.8, 25.8; HRMS calcd for C12H13ClO2 224.0624, found
224.0626.
1-(2-Chlorophenyl)-2-(tetrahydrofuran-2-yl)ethanone (2h). Yel-
1
low oil: H NMR (400 MHz, CDCl3) δ 7.53−7.50 (m, 1 H), 7.42−
7.30 (m, 3 H), 4.38−4.31 (m, 1 H), 3.87 (q, J = 11.2 Hz, 1 H), 3.74
(q, J = 9.2 Hz, 1 H), 3.29 (q, J = 12.4 Hz, 1 H), 3.12 (q, J = 13.6 Hz, 1
H), 2.20−2.11 (m, 1 H), 1.97−1.87 (m, 1 H), 1.64−1.54 (m, 1 H);
13C NMR (100 MHz, CDCl3) δ 201.6, 139.6, 131.9, 131.0, 130.7,
129.3, 127.1, 75.4, 68.0, 49.1, 31.7, 25.8; HRMS calcd for C12H13ClO2
224.0624, found 224.0623.
1-(2-Bromophenyl)-2-(tetrahydrofuran-2-yl)ethanone (2i). Yel-
1
low oil: H NMR (400 MHz, CDCl3) δ 7.61−7.58 (m, 1 H), 7.45−
7.43 (m, 1 H), 7.39−7.36 (m, 1 H), 7.30−7.27 (m, 1 H), 4.37−4.31
(m, 1 H), 3.90−3.84 (m, 1 H), 3.76−3.71 (m, 1 H), 3.25 (q, J = 9.2
Hz, 1 H), 3.10 (q, J = 10.0 Hz, 1 H), 2.20−2.12 (m, 1 H), 1.94−1.89
(m, 1 H), 1.66−1.57 (m, 1 H); 13C NMR (100 MHz, CDCl3) δ 202.4,
141.8, 133.7, 131.7, 128.9, 127.6, 118.7, 75.3, 68.0, 48.8, 32.3, 25.7;
HRMS calcd for C12H13BrO2 268.0099, found 268.0101.
Characterization Data of All Products. 1-Phenyl-2-(tetrahy-
1
drofuran-2-yl)ethanone (2a). Light yellow oil: H NMR (400
MHz, CDCl3) δ 7.98−7.95 (m, 2 H), 7.58−7.54 (m, 1 H),
7.48−7.44 (m, 2 H), 4.43−4.38 (m, 1 H), 3.92−3.87 (m, 1 H),
3.78−3.73 (m, 1 H), 3.40 (q, J = 10.0 Hz, 1 H), 3.06 (q, J =
10.2 Hz, 1 H), 2.24−2.16 (m, 1 H), 1.97−1.89 (m, 1 H), 1.64−
1.39 (m, 1 H); 13C NMR (100 MHz, CDCl3) δ 198.6, 137.2,
133.2, 128.7, 128.4, 75.6, 68.0, 44.8, 31.8, 25.8; HRMS calcd for
C12H14O2 190.0994, found 190.0991.
1-(4-Bromophenyl)-2-(tetrahydrofuran-2-yl)ethanone (2j). Light
1
yellow solid (mp 43−45 °C): H NMR (400 MHz, CDCl3) δ 7.84−
7.81 (m, 2 H), 7.61−7.58 (m, 2 H), 4.41−4.34 (m, 1 H), 3.91−3.86
(m, 1 H), 3.77−3.72 (m, 1 H), 3.33 (q, J = 10.0 Hz, 1 H), 3.01 (q, J =
9.6 Hz, 1 H), 2.23−2.15 (m, 1 H), 1.96−1.88 (m, 1 H), 1.59−1.52
(m, 1 H); 13C NMR (100 MHz, CDCl3) δ 197.6, 135.9, 131.2, 129.9,
128.4, 75.4, 68.0, 44.7, 31.8, 25.7; HRMS calcd for C12H13BrO2
268.0099, found 268.0098.
2-(Tetrahydrofuran-2-yl)-1-p-tolyethanone (2b). Yellow oil: 1H
NMR (400 MHz, CDCl3) δ 7.87 (d, J = 10.8 Hz, 2 H), 7.23 (d, J =
14.0 Hz, 2 H), 4.44−4.36 (m, 1 H), 3.90 (q, J = 10.4 Hz, 1 H), 3.75
(q, J = 9.6 Hz, 1 H), 3.38 (q, J = 13.2 Hz, 1 H), 3.03 (q, J = 12.4 Hz,
1 H), 2.41 (s, 3 H), 2.30−2.14 (m, 1 H), 1.96−1.88 (m, 1 H), 1.62−
1.56 (m, 1 H); 13C NMR (100 MHz, CDCl3) δ 198.2, 144.1, 134.8,
129.4, 128.5, 75.7, 68.0, 44.7, 31.8, 25.8, 21.8; HRMS calcd for
C13H16O2 204.1150, found 204.1154.
1-(Naphthalen-2-yl)-2-(tetrahydrofuran-2-yl)ethanone (2k). Yel-
1
low oil: H NMR (400 MHz, CDCl3) δ 8.49 (s, 1 H), 8.05−8.03
(m, 1 H), 7.97 (d, J = 8.0 Hz, 1 H), 7.91−7.87 (m, 2 H), 7.62−7.53
(m, 2 H), 4.49−4.45 (m, 1 H), 3.95−3.90 (m, 1 H), 3.78 (q, J = 6.8
Hz, 1 H), 3.54 (q, J = 10.0 Hz, 1 H), 3.19 (q, J = 9.2 Hz, 1 H), 2.24−
2.21 (m, 1 H), 1.99−1.93 (m, 1 H), 1.66−1.54 (m, 1 H); 13C NMR
(100 MHz, CDCl3) δ 198.5, 135.8, 134.6, 132.7, 130.2, 129.8, 128.6,
128.5, 127.9, 126.9, 124.0, 75.7, 68.0, 44.9, 31.8, 25.8; HRMS calcd for
C16H16O2 240.1150, found 240.1151.
2-(Tetrahydrofuran-2-yl)-1-m-tolyethanone (2c). Yellow oil: 1H
NMR (400 MHz, CDCl3) δ 7.78−7.75 (m, 2 H), 7.39−7.32 (m, 2 H),
4.44−4.36 (m, 1 H), 3.92−3.88 (m, 1 H), 3.78−3.72 (m, 1 H), 3.38
(q, J = 10.0 Hz, 1 H), 3.04 (q, J = 9.6 Hz, 1 H), 2.41 (s, 3 H), 2.23−
2.15 (m, 1 H), 1.97−1.88 (m, 1 H), 1.61−1.56 (m, 1 H); 13C NMR
(100 MHz, CDCl3) δ 198.8, 138.5, 137.3, 134.0, 128.8, 128.6, 126.0,
75.6, 68.0, 44.9, 31.8, 25.8, 21.5; HRMS calcd for C13H16O2 204.1150,
found 204.1148.
2-(1,4-Dioxan-2-yl)-1-phenylethanone (2l). Light yellow oil: 1H
NMR (400 MHz, CDCl3) δ 7.99−7.94 (m, 2 H), 7.59−7.54 (m, 1 H),
7.50−7.45 (m, 2 H), 4.28−4.21 (m, 1 H), 3.93−3.89 (m, 1 H), 3.80−
3.71 (m 3 H), 3.70−3.60 (m, 1 H), 3.38 (q, J = 10.0 Hz, 1 H), 3.24
(q, J = 9.2 Hz, 1 H), 2.89 (q, J = 10.4 Hz, 1 H); 13C NMR (100 MHz,
CDCl3) δ 197.1, 136.9, 133.3, 128.9, 128.2, 71.8, 71.0, 66.9, 40.7;
HRMS calcd for C12H14O3 206.0693, found 206.0690.
2-(Tetrahydrofuran-2-yl)-1-o-tolyethanone (2d). Yellow oil: 1H
NMR (400 MHz, CDCl3) δ 7.67−7.65 (m, 1 H), 7.39−7.34 (m, 1 H),
7.27−7.23 (m, 2 H), 4.39−4.33 (m, 1 H), 3.91−3.86 (m, 1 H), 3.75
(q, J = 6.8 Hz, 1 H), 3.28 (q, J = 9.2 Hz, 1 H), 3.00 (q, J = 10.0 Hz,
1 H), 2.51 (s, 3 H), 2.20−2.12 (m, 1 H), 1.96−1.88 (m, 1 H), 1.60−
1.51 (m, 1 H); 13C NMR (100 MHz, CDCl3) δ 202.6, 138.4, 138.1,
132.1, 131.5, 128.8, 125.8, 75.7, 68.0, 47.7, 31.7, 25.8, 21.4; HRMS
calcd for C13H16O2 204.1150, found 204.1151.
1-Phenyl-2-(tetrahydrofuran-2-yl)propan-1-one (2m). Yellow oil:
1H NMR (400 MHz, CDCl3) δ 8.00−7.97 (m, 2 H), 7.57−7.52 (m, 1 H),
7.48−7.44 (m, 2 H), 4.21−4.15 (m, 1 H), 3.88−3.81 (m, 1 H), 3.75−
3.69 (m, 1 H), 3.65−3.58 (m, 1 H), 2.09−2.00 (m, 1 H), 1.95−1.87
(m, 2 H), 1.69−1.60 (m, 1 H), 1.17 (d, J = 6.8 Hz, 3 H); 13C NMR
(100 MHz, CDCl3) δ 203.2, 137.3, 133.0, 128.7, 128.6, 81.0, 68.3,
46.0, 29.3, 25.8, 14.0; HRMS calcd for C13H16O2 204.1150, found
204.1152.
1-(4-Methoxyphenyl)-2-(tetrahydrofuran-2-yl)ethanone (2e). Yel-
1
low oil: H NMR (400 MHz, CDCl3) δ 7.95−7.93 (m, 1 H), 7.04−
7.02 (m, 1 H), 4.23−4.20 (m, 1 H), 3.84 (s, 3 H), 3.76−3.72 (m, 1 H),
3.60−3.56 (m, 1 H), 3.24 (q, J = 9.6 Hz, 1 H), 3.01 (q, J = 9.6 Hz,
1 H), 2.51−2.49 (m, 1 H), 1.84−1.82 (m, 1 H), 1.52−1.47 (m, 1 H);
13C NMR (100 MHz, CDCl3) δ 197.3, 163.6, 130.9, 130.4, 114.3, 75.7,
67.3, 56.0, 44.2, 31.6, 25.5; HRMS calcd for C13H16O3 220.1099, found
220.1100.
1-(2-Bromophenyl)-2-(tetrahydrofuran-2-yl)propan-1-one (2n).
Yellow oil: 1H NMR (400 MHz, CDCl3) δ 7.57−7.55 (m, 1 H),
7.36−7.32 (m, 1 H), 7.28−7.24 (m, 1 H), 7.21−7.18 (m, 1 H), 3.85−
3.81 (m, 2 H), 3.66−3.60 (m, 1 H), 3.37−3.31 (m, 1 H), 2.38−2.30
(m, 2 H), 1.95 (d, J = 4.8 Hz, 3 H), 1.69−1.62 (m, 2 H); 13C NMR
(100 MHz, CDCl3) δ 198.2, 149.8, 133.0, 130.5, 128.7, 127.1, 119.7,
67.1, 66.4, 32.5, 28.5, 26.4, 11.0; HRMS calcd for C13H15BrO2
282.0255, found 282.0254.
1-(2-Methoxyphenyl)-2-(tetrahydrofuran-2-yl)ethanone (2f). Yel-
1
low oil: H NMR (400 MHz, CDCl3) δ 7.73−7.70 (m, 1 H), 7.48−
7.43 (m, 1 H), 7.02−6.95 (m, 1 H), 4.38−4.35 (m, 1 H), 3.90 (s, 3 H),
3.89−3.85 (m, 1 H), 3.73 (q, J = 8.4 Hz, 1 H), 3.39 (q, J = 10.8 Hz, 1 H),
1-(4-Methoxyphenyl)-2-(tetrahydrofuran-2-yl)propan-1-one
(2o). Yellow oil: 1H NMR (400 MHz, CDCl3) δ 8.00−7.96 (m, 2 H),
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The Journal of Organic Chemistry
Note
6.95−6.92 (m, 2 H), 4.19−4.13 (m, 1 H), 3.87 (s, 3 H), 3.85−3.81
(m, 2 H), 3.74−3.69 (m, 1 H), 3.59−3.55 (m, 1 H), 2.04−2.00 (m, 1 H),
1.94−1.88 (m, 2 H), 1.68−1.61 (m, 1 H), 1.15 (d, J = 7.2 Hz,
3 H); 13C NMR (100 MHz, CDCl3) δ 201.6, 163.6, 130.9, 130.3,
113.9, 81.1, 68.3, 55.6, 45.5, 29.8, 25.8, 14.0; HRMS calcd for
C14H18O3 234.1256, found 234.1257.
1-(4-Bromophenyl)-2-(tetrahydrofuran-2-yl)propan-1-one (2p).
Yellow oil: 1H NMR (400 MHz, CDCl3) δ 7.86−7.82 (m, 2 H),
7.63−7.58 (m, 2 H), 4.15−4.07 (m, 1 H), 3.85−3.79 (m, 1 H), 3.77−
3.68 (m, 2 H), 3.58−3.49 (m, 1 H), 2.09−1.97 (m, 2 H), 1.95−1.88
(m, 2 H), 1.87−1.79 (m, 2 H), 1.67−1.61 (m, 2 H), 1.58−1.49 (m, 1
H), 1.29 (d, J = 6.8 Hz, 3 H), 1.15 (d, J = 6.8 Hz, 3 H); 13C NMR
(100 MHz, CDCl3) δ 202.3, 202.2, 136.1, 135.9, 132.1, 131.9, 130.2,
130.1, 128.4, 128.2, 81.2, 81.1, 68.3, 68.1, 16.1, 45.9, 29.6, 29.5, 25.9,
25.7, 15.4, 14.0; HRMS calcd for C13H15BrO2 282.0255, found
282.0257.
2-(1,3-Dioxolan-2-yl)-1-p-tolylethanone (3b). Yellow oil: 1H
NMR (400 MHz, CDCl3) δ 7.87 (d, J = 8.4 Hz, 2 H), 7.26 (d, J =
8.0 Hz, 2 H), 5.44 (t, J = 5.2 Hz, 1 H), 4.02−3.96 (m, 2 H), 3.95−3.89
(m, 2 H), 3.32 (d, J = 5.2 Hz, 2 H), 2.41 (s, 3 H); 13C NMR (100
MHz, CDCl3) δ 196.3, 144.3, 134.7, 129.5, 128.6, 101.6, 65.2, 43.5,
21.8; HRMS calcd for C12H14O3 206.0943, found 206.0944.
2-(1,3-Dioxolan-2-yl)-1-m-tolylethanone (3c). Yellow oil: 1H
NMR (400 MHz, CDCl3) δ 7.77−7.75 (m, 2 H), 7.40−7.33 (m, 2 H),
5.44 (t, J = 5.2 Hz, 1 H), 4.03−3.97 (m, 2 H), 3.95−3.89 (m, 2 H), 3.33
(d, J = 5.2 Hz, 2 H), 2.41 (s, 3 H); 13C NMR (100 MHz, CDCl3) δ 196.9,
138.6, 137.1, 134.3, 128.9, 128.6, 125.7, 101.6, 65.1, 43.6, 43.6, 21.5; HRMS
calcd for C12H14O3 206.0943, found 206.0942.
2-(1,3-Dioxolan-2-yl)-1-o-tolylethanone (3d). Yellow oil: 1H NMR
(400 MHz, CDCl3) δ 7.68−7.66 (m, 1 H), 7.40−7.36 (m, 1 H), 7.28−
7.23 (m, 2 H), 5.40 (t, J = 4.8 Hz, 1 H), 4.01−3.95 (m, 2 H), 3.94−
3.88 (m, 2 H), 3.28 (d, J = 4.8 Hz, 2 H), 2.52 (s, 3 H); 13C NMR
(100 MHz, CDCl3) δ 200.3, 138.8, 137.7, 132.2, 131.8, 129.1, 125.8,
101.7, 65.1, 46.2, 21.5; HRMS calcd for C12H14O3 206.0943, found
206.0946.
1,2-Diphenyl-2-(tetrahydrofuran-2-yl)ethanone (2q). Yellow oil:
1H NMR (400 MHz, CDCl3) δ 8.00−7.94 (m, 2 H), 7.51−7.47 (m, 1 H),
7.47−7.38 (m, 4 H), 7.33−7.28 (m, 2 H), 7.25−7.20 (m, 1 H),
4.75−4.53 (m, 2 H), 3.88−3.67 (m, 2 H), 2.28−2.12 (m, 1 H), 1.93−
1.80 (m, 2 H), 1.78−1.68 (m, 1 H), 1.61−1.51 (m, 1 H); 13C NMR
(100 MHz, CDCl3) δ 199.1, 198.9, 137.5, 137.2, 136.9, 136.3, 133.2,
133.0, 129.1, 129.0, 138.9, 128.8, 128.8, 128.7, 128.6, 127.7, 127.5,
81.5, 80.8, 68.5, 68.1, 59.3, 59.1, 31.0, 29.8, 25.8, 25.6; HRMS calcd for
C18H18O2 266.1307, found 266.1305.
2-(1,3-Dioxolan-2-yl)-1-(4-methoxyphenyl)ethanone (3e). Yellow
1
oil: H NMR (400 MHz, CDCl3) δ 7.96−7.94 (m, 2 H), 6.96−6.93
(m, 2 H), 5.43 (t, J = 5.2 Hz, 1 H), 4.02−3.96 (m, 2 H), 3.95 (s, 3 H),
3.92−3.87 (m, 2 H), 3.30 (d, J = 4.8 Hz, 2 H); 13C NMR (100 MHz,
CDCl3) δ 195.2, 163.9, 130.8, 130.3, 113.9, 101.7, 65.1, 55.6, 43.2;
HRMS calcd for C12H14O4 222.0892, found 222.0890.
2-(1,3-Dioxolan-2-yl)-1-(2-methoxyphenyl)ethanone (3f). Yellow
1-(4-Methoxyphenyl)-2-phenyl-2-(tetrahydrofuran-2-yl)-
ethanone and 2-(4-Methoxyphenyl)-1-phenyl-2-(tetrahydrofuran-
2-yl)ethanone (2r). Yellow oil: 1H NMR (400 MHz, CDCl3) δ 7.98−
7.93 (m, 2 H), 7.52−7.45 (m, 1 H), 7.41−7.36 (m, 2 H), 7.32−7.27
(m, 2 H), 6.90−6.82 (m, 2 H), 4.71−4.48 (m, 2 H), 3.86−3.67 (m, 2
H), 3.82 (s, 3 H), 3.79 (s, 3H), 3.74 (s, 3 H), 2.31−2.18 (m, 1 H),
1.95−1.68 (m, 2 H), 1.62−1.48 (m, 1 H); 13C NMR (100 MHz,
CDCl3) δ 199.3, 199.2, 197.5, 163.5, 159.0, 158.9, 137.8, 137.1, 136.8,
133.0, 132.8, 131.0, 129.8, 129.7, 129.6, 129.4, 128.8, 128.7, 128.6,
128.4, 127.6, 114.4. 114.3, 113.8, 81.5, 81.4, 80.6, 68.4, 68.0, 58.9, 58.4,
58.0, 55.5, 55.2, 55.1, 30.9, 30.8, 29.7, 25.7, 25.5; HRMS calcd for
C19H20O3 296.1412, found 296.1411.
1-(2-Methoxyphenyl)-2-phenyl-2-(tetrahydrofuran-2-yl)-
ethanone and 2-(2-Methoxyphenyl)-1-phenyl-2-(tetrahydrofuran-
2-yl)ethanone (2s). Yellow oil: 1H NMR (400 MHz, CDCl3) δ 8.06−
7.99 (m, 2 H), 7.47−7.43 (m, 1 H), 7.39−7.32 (m, 4 H), 7.23−7.20
(m, 2 H), 7.08−7.02 (m, 2 H), 6.92−6.84 (m, 2 H), 5.24−5.18 (m, 1
H), 4.70−4.61 (m, 2 H), 3.95 (s, 3 H), 3.92 (s, 3 H), 3.82 (s, 3 H),
3.91−3.69 (m, 2 H), 2.22−2.17 (m, 1 H), 1.91−1.84 (m, 2 H), 1.61−
1.53 (m, 1 H), 13C NMR (100 MHz, CDCl3) δ 202.3, 201.5, 199.7,
199.1, 156.7, 156.3, 137.4, 136.9, 136.8, 136.5, 133.3, 133.1, 132.8,
132.7, 130.9, 129.2, 128.8, 128.7, 128.6, 128.5, 128.4, 128.3, 127.2,
127.0, 121.2, 121.1, 120.7, 120.6, 111.4, 111.3, 111.0, 110.8, 81.5, 81.2,
80.8, 80.7, 68.7, 68.5, 68.3, 67.9, 55.8, 55.6, 55.3, 55.2, 50.2, 49.5, 30.8,
30.6, 29.7, 28.8, 25.7, 25.6, 25.5, 25.4; HRMS calcd for C19H20O3
296.1412, found 296.1411.
1
oil: H NMR (400 MHz, CDCl3) δ 7.77−7.75 (m, 1 H), 7.49−7.45
(m, 1 H), 7.02−6.95 (m, 2 H), 5.43 (t, J = 4.8 Hz, 1 H), 4.00−3.96
(m, 2 H), 3.91 (s, 3 H), 3.90−3.88 (m, 2 H), 3.41 (d, J = 5.2 Hz, 2 H);
13C NMR (100 MHz, CDCl3) δ 198.2, 158.9, 134.0, 130.8, 128.0,
120.9, 111.7, 101.5, 65.1, 55.6, 48.8; HRMS calcd for C12H14O4
222.0892, found 222.0891.
1-(4-Chlorophenyl)-2-(1,3-dioxolan-2-yl)ethanone (3g). Light
yellow oil: 1H NMR (400 MHz, CDCl3) δ 7.92−7.89 (m, 2 H),
7.46−7.43 (m, 2 H), 5.42 (t, J = 4.8 Hz, 1 H), 4.02−3.96 (m, 2 H),
3.95−3.89 (m, 2 H), 3.31 (d, J = 5.2 Hz, 2 H); 13C NMR (100 MHz,
CDCl3) δ 195.5, 140.0, 135.5, 129.9, 129.1, 101.4, 65.2, 43.6; HRMS
calcd for C11H11ClO3 226.0397, found 226.0396.
1-(2-Chlorophenyl)-2-(1,3-dioxolan-2-yl)ethanone (3h). Orange
1
oil: H NMR (400 MHz, CDCl3) δ 7.55−7.53 (m, 1 H), 7.42−7.40
(m, 2 H), 7.36−7.31 (m, 1 H), 5.39 (t, J = 4.8 Hz, 1 H), 3.99−3.96
(m, 2 H), 3.93−3.86 (m, 2 H), 3.36 (d, J = 5.2 Hz, 2 H); 13C NMR
(100 MHz, CDCl3) δ 199.4, 139.2, 132.2, 131.3, 130.7, 129.6, 127.1,
101.4, 65.2, 47.8; HRMS calcd for C11H11ClO3 226.0397, found
226.0395.
1-(2-Bromophenyl)-2-(1,3-dioxolan-2-yl)ethanone (3i). Orange
1
oil: H NMR (400 MHz, CDCl3) δ 7.62−7.59 (m, 1 H), 7.48−7.46
(m, 1 H), 7.39−7.35 (m, 1 H), 7.32−7.28 (m, 1 H), 5.38 (t, J = 5.2
Hz, 1 H), 3.99−3.93 (m, 2 H), 3.92−3.86 (m, 2 H), 3.34 (d, J = 4.8
Hz, 1 H); 13C NMR (100 MHz, CDCl3) δ 200.2, 141.4, 133.8, 132.0,
129.2, 127.6, 118.9, 101.3, 65.1, 47.4; HRMS calcd for C11H11BrO3
269.9892, found 269.9890.
1-(2-Bromophenyl)-2-phenyl-2-(tetrahydrofuran-2-yl)ethanone
and 2-(2-Bromophenyl)-1-phenyl-2-(tetrahydrofuran-2-yl)-
1-(4-Bromophenyl)-2-(1,3-dioxolan-2-yl)ethanone (3j). Yellow
1
1
ethanone (2t). Yellow oil: H NMR (400 MHz, CDCl3) δ 8.10−
oil: H NMR (400 MHz, CDCl3) δ 7.84−7.81 (m, 2 H), 7.62−7.59
8.07 (m, 1 H), 8.01−7.98 (m, 1 H), 7.61−7.59 (m, 1 H), 7.52−7.48
(m, 1 H), 7.42−7.39 (m, 3 H), 7.25−7.20 (m, 1 H), 7.09−7.05 (m, 1 H),
5.44−5.42 (m, 1 H), 5.25−5.17 (m, 1 H), 4.78−4.52 (m, 2 H), 3.91−
3.85 (m, 4 H), 2.29−2.18 (m, 2 H), 1.94−1.82 (m, 6 H), 1.74−1.64
(m, 2 H); 13C NMR (100 MHz, CDCl3) δ 202.4, 198.9, 198.5, 141.9,
136.9, 136.6, 135.8, 135.6, 135.1, 133.6, 133.5, 133.4, 133.2, 133.1,
131.3, 131.2, 129.7, 129.3, 129.2, 129.0, 128.8, 128.8, 128.7, 128.6,
128.5, 128.0, 127.9, 125.8, 125.1, 81.5, 81.4, 80.7, 68.6, 68.4, 68.1, 67.0,
63.0, 62.9, 56.9, 55.8, 32.3, 31.1, 30.5, 25.8, 25.6, 25.4; HRMS calcd for
C18H17BrO2 344.0412, found 344.0410.
(m, 2 H), 5.41 (t, J = 4.8 Hz, 1 H), 4.02−3.96 (m, 2 H), 3.94−3.88
(m, 2 H), 3.30 (d, J = 5.2 Hz, 2 H); 13C NMR (100 MHz, CDCl3) δ
195.7, 135.8, 132.1, 130.0, 128.7, 101.4, 65.2, 43.5; HRMS calcd for
C11H11BrO3 269.9892, found 269.9895.
2-(1,3-Dioxolan-2-yl)-1-(naphthalen-2-yl)ethanone (3k). Yellow
oil: 1H NMR (400 MHz, CDCl3) δ 8.48 (s, 1 H), 8.04 (q, J = 6.8 Hz,
1 H), 7.97 (d, J = 8.0 Hz, 1 H), 7.89 (t, J = 8.4 Hz, 2 H), 7.63−7.54
(m, 2 H), 5.51 (t, J = 4.8 Hz, 1 H), 4.05−3.99 (m, 2 H), 3.97−3.91
(m, 2 H), 3.48 (d, J = 5.2 Hz, 1 H); 13C NMR (100 MHz, CDCl3) δ
196.6, 135.9, 134.5, 132.6, 130.5, 129.8, 128.8, 128.7, 127.9, 127.0,
124.0, 101.7, 65.2, 43.6; HRMS calcd for C15H14O3 242.0943, found
242.0941.
2-(1,3-Dioxolan-2-yl)-1-phenylethanone (3a). Light yellow oil: 1H
NMR (400 MHz, CDCl3) δ 7.98−7.96 (m, 2 H), 7.60−7.55 (m, 1 H),
7.49−7.45 (m, 2 H), 5.45 (t, J = 5.2 Hz, 1 H). 4.03−3.99 (m, 2 H),
3.93−3.89 (m, 2 H), 3.35 (d, J = 5.2 Hz, 2 H); 13C NMR (100 MHz,
CDCl3) δ 196.7, 137.1, 133.5, 129.0, 128.8, 128.5, 101.5, 65.2, 43.5;
HRMS calcd for C11H12O3 192.0786, found 192.0785.
1
2-(1,3-Dioxolan-2-yl)-1-phenylpropan-1-one (3l). Yellow oil: H
NMR (400 MHz, CDCl3) δ 7.98−7.96 (m, 2 H), 7.59−7.55 (m, 1 H),
7.49−7.45 (m, 2 H), 5.16 (d, J = 5.6 Hz, 1 H), 3.98−3.92 (m, 2 H),
3.90−3.83 (m, 2 H), 3.71 (q, J = 13.2 Hz, 1 H), 1.31 (d, J = 6.8 Hz, 3 H);
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The Journal of Organic Chemistry
Note
13C NMR (100 MHz, CDCl3) δ 201.2, 137.0, 133.3, 128.7, 128.6,
128.5, 105.5, 65.3, 65.1, 45.5, 13.2; HRMS calcd for C12H14O3
206.0943, found 206.0946.
(m, 2 H), 7.48−7.44 (m, 1 H), 7.36−7.31 (m, 2 H), 7.17−7.13
(m, 4 H), 7.11−7.08 (m, 1 H), 5.15 (d, J = 6.0 Hz, 1 H) 4.13−3.70
(m, 5 H), 3.26−3.20 (m, 1 H), 3.14−3.10 (m, 1 H); 13C NMR (100
MHz, CDCl3) δ 200.6, 139.1, 138.2, 133.0, 129.2, 128.5, 128.4, 128.4,
126.4, 105.0, 65.3, 65.1, 53.1, 34.6; HRMS calcd for C18H18O3
288.1256, found 288.1257.
2-(1,3-Dioxolan-2-yl)-1-(4-methoxyphenyl)propan-1-one (3m).
1
Orange oil: H NMR (400 MHz, CDCl3) δ 7.99−7.95 (m, 2 H),
6.96−6.92 (m, 2 H), 5.14 (d, J = 9.6 Hz, 1 H), 3.98−3.92 (m, 2 H),
3.90 (s, 3 H), 3.89−3.83 (m, 1 H), 3.65 (q, J = 13.2 Hz, 1 H), 1.29
(d, J = 6.8 Hz, 3 H); 13C NMR (100 MHz, CDCl3) δ 199.6, 163.7,
131.0, 129.9, 113.9, 105.7, 65.3, 65.0, 55.6, 45.0, 13.3; HRMS calcd for
C13H16O4 236.1049, found 236.1050.
ASSOCIATED CONTENT
■
S
* Supporting Information
1
Experimental procedures and characterization data, H NMR
1-(4-Bromophenyl)-2-(1,3-dioxolan-2-yl)propan-1-one (3n). Yel-
and 13C NMR spectra for all the compounds. This material is
available free of charge via the Internet at http://pubs.acs.org.
1
low oil: H NMR (400 MHz, CDCl3) δ 7.85−7.82 (m, 2 H), 7.62−
7.59 (m, 2 H), 5.11 (d, J = 6.0 Hz, 1 H), 3.96−3.89 (m, 2 H), 3.88−
3.82 (m, 2 H), 3.68−3.63 (m, 1 H), 1.29 (d, J = 6.8 Hz, 3 H); 13C
NMR (100 MHz, CDCl3) δ 200.2, 135.7, 132.0, 130.2, 128.5, 105.4,
65.3, 65.1, 45.5, 13.1; HRMS calcd for C12H13BrO3 284.0048, found
284.0050.
AUTHOR INFORMATION
Corresponding Author
*E-mail: zwang3@ustc.edu.cn; zgzha@ustc.edu.cn.
■
2-(1,3-Dioxolan-2-yl)-1,2-diphenylethanone (3o). Light yellow
1
Notes
solid (mp 57−59 °C): H NMR (400 MHz, CDCl3) δ 7.98−7.95
(m, 2 H), 7.51−7.43 (m, 1 H), 7.42−7.40 (m, 4 H), 7.37−7.29 (m, 2 H),
7.25−7.22 (m, 1 H), 5.63 (d, J = 6.8 Hz, 1 H), 4.73 (d, J = 6.8 Hz,
1 H), 3.96−3.88 (m, 3 H), 3.86−3.81 (m, 1 H); 13C NMR (100 MHz,
CDCl3) δ 197.5, 136.7, 134.6, 133.3, 129.1, 129.0, 128.9, 128.7, 127.9,
105.4, 65.4, 65.2, 58.2; HRMS calcd for C17H16O3 266.1099, found
266.1097.
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
We are grateful for financial support from the National Science
Foundation of China (No. 20772118, 20932002, 20972144,
21172205, J1030412, and 90813008), Ministry of Science and
Technology (2010CB912103), and the Chinese Academy of
Sciences.
1-(4-Bromophenyl)-2-(1,3-dioxolan-2-yl)-2-phenylethanone and
2-(4-Bromophenyl)-2-(1,3-dioxolan-2-yl)-1-phenylethanone (3p).
1
Light yellow oil: H NMR (400 MHz, CDCl3) δ 7.95−7.92 (m, 1
H), 7.82−7.80 (m, 1 H), 7.54−7.48 (m, 2 H), 7.47−7.38 (m, 3 H),
7.35−7.26 (m, 2H), 5.60 (d, J = 6.8 Hz, 1 H), 5.57 (d, J = 6.8 Hz, 1
H), 4.71 (d, J = 6.8 Hz, 1 H), 4.65 (d, J = 7.2 Hz, 1 H), 3.95−3.81
(m, (m, 4 H); 13C NMR (100 MHz, CDCl3) δ 197.1, 196.5, 136.5,
135.4, 134.2, 133.6, 133.5, 132.2, 132.0, 130.8, 130.4, 129.2, 129.1,
128.9, 128.8, 128.6, 122.2, 105.2, 105.1, 65.4, 65.3, 65.2, 58.3, 57.5;
HRMS calcd for C17H15BrO3 346.0205, found 346.0206.
2-(1,3-Dioxolan-2-yl)-1-(4-methoxyphenyl)-2-phenylethanone
and 2-(1,3-Dioxolan-2-yl)-2-(4-methoxyphenyl)-1-phenylethanone
(3q). Orange oil: 1H NMR (400 MHz, CDCl3) δ 7.97−7.94 (m, 2 H),
7.49−7.37 (m, 2 H), 7.35−7.30 (m, 2 H), 7.27−7.23 (m, 1 H), 6.88−
6.85 (m, 2 H), 5.62 (d, J = 7.2 Hz, 1 H), 5.58 (d, J = 6.8 Hz, 1 H), 4.68
(d, J = 2.0 Hz, 1 H), 4.66 (d, J = 2.0 Hz, 1 H), 3.95−3.88 (m, 3 H),
3.86−3.82 (m, 1 H), 3.81 (s, 3 H), 3.75 (s, 3 H); 13C NMR (100
MHz, CDCl3) δ 197.7, 195.9, 163.7, 159.4, 136.7, 135.0, 133.2, 131.3,
130.1, 129.0, 128.9, 128.7, 127.8, 114.6, 113.9, 105.5, 105.4, 65.4, 65.3,
65.2, 57.9, 57.4, 55.6, 55.3; HRMS calcd for C18H18O4 298.1205, found
298.1206.
2-(1,3-Dioxolan-2-yl)-1-(2-methoxyphenyl)-2-phenylethanone
and 2-(1,3-Dioxolan-2-yl)-2-(2-methoxyphenyl)-1-phenylethanone
(3r). Yellow oil: 1H NMR (400 MHz, CDCl3) δ 8.04−8.01 (m, 2 H),
7.72−7.69 (m, 1H), 7.49−7.45 (m, 1 H), 7.39−7.36 (m, 6 H), 7.24−
7.20 (m, 4 H), 6.93−6.89 (m, 4 H), 5.70 (d, J = 7.2 Hz, 1 H), 5.59 (d,
J = 6.8 Hz, 1 H), 5.34 (d, J = 6.8 Hz, 1 H), 4.88 (d, J = 6.8 Hz, 1 H),
3.98−3.86 (m, 8 H), 3.92 (s, 3 H), 3.81 (s, 3H); 13C NMR (100 MHz,
CDCl3) δ 199.6, 198.0, 158.3, 156.7, 136.6, 134.8, 133.7, 133.0, 131.1,
129.5, 128.9, 128.7, 128.4, 128.3, 127.3, 126.5, 123.5, 121.1, 120.7,
111.5, 105.6, 65.2, 65.1, 65.0, 55.9, 55.3, 49.2; HRMS calcd for
C18H18O4 298.1205, found 298.1207.
1-(2-Bromophenyl)-2-(1,3-dioxolan-2-yl)-2-phenylethanone and
2-(2-Bromophenyl)-2-(1,3-dioxolan-2-yl)-1-phenylethanone (3s).
Yellow oil: 1H NMR (400 MHz, CDCl3) δ 8.04−8.01 (m, 2 H),
7.64−7.62 (m, 1 H), 7.53−7.48 (m, 2 H), 7.47−7.39 (m, 4 H), 7.26−
7.22 (m, 1H), 7.13−7.10 (m, 8 H), 5.71 (d, J = 6.8 Hz, 1 H), 5.62 (d,
J = 8 Hz, 1 H), 5.37 (d, J = 6.8 Hz, 1 H), 5.34 (d, J = 4.4 Hz, 1 H),
4.03−3.85 (m, (m, 8 H); 13C NMR (100 MHz, CDCl3) δ 197.3,
141.0, 136.9, 136.4, 134.2, 133.5, 133.4, 132.6, 129.6, 129.5, 128.9,
128.8, 128.6, 128.0, 127.8, 127.3, 127.0, 125.7, 105.7, 65.4, 65.3, 65.2,
64.8, 55.9, 54.6; HRMS calcd for C17H15BrO3 346.0205, found
346.0203.
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