Iridium Complexes as Efficient Catalysts for Construction of α-Substituted Ketones via Hydrogen Borrowing of Alcohols in Water

Article abstract of DOI:10.1002/ejoc.202001550

Ketones are of great importance in synthesis, biology, and pharmaceuticals. This paper reports an iridium complexes-catalyzed cross-coupling of alcohols via hydrogen borrowing, affording a series of α-alkylated ketones in high yield (86 %–95 %) and chemoselectivities (>99 : 1). This methodology has the advantages of low catalyst loading (0.1 mol%) and environmentally benign water as the solvent. Studies have shown the amount of base has a great impact on chemoselectivities. Meanwhile, deuteration experiments show water plays an important role in accelerating the reduction of the unsaturated ketones intermediates. Remarkably, a gram-scale experiment demonstrates this methodology of iridium-catalyzed cross-coupling of alcohols has potential application in the practical synthesis of α-alkylated ketones.

Full text of DOI:10.1002/ejoc.202001550

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Iridium Complexes as Efficient Catalysts for Construction of
α-Substituted Ketones via Hydrogen Borrowing of Alcohols
in Water
Nianhua Luo,[a] Yuhong Zhong,[a] Huiling Wen,[a] Hongling Shui,[a] and Renshi Luo*[a]
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Ketones are of great importance in synthesis, biology, and
pharmaceuticals. This paper reports an iridium complexes-
catalyzed cross-coupling of alcohols via hydrogen borrowing,
affording a series of α-alkylated ketones in high yield (86%–
95%) and chemoselectivities (>99:1). This methodology has
the advantages of low catalyst loading (0.1 mol%) and environ-
mentally benign water as the solvent. Studies have shown the
amount of base has a great impact on chemoselectivities.
Meanwhile, deuteration experiments show water plays an
important role in accelerating the reduction of the unsaturated
ketones intermediates. Remarkably, a gram-scale experiment
demonstrates this methodology of iridium-catalyzed cross-
coupling of alcohols has potential application in the practical
synthesis of α-alkylated ketones.
Introduction
Ketones are of great importance in synthesis, biology, and
pharmaceuticals.[1] Therefore, the development of efficient
methods for the synthesis of ketones is fundamentally
important in organic chemistry. Traditionally, the ketone
enolate and alkyl halides were employed in the preparation of
α-alkylated ketones, which has the disadvantages of hazardous
waste and side products.[2] Compared with the traditional
strategy, the hydrogen borrowing method is an attractive one
for the formation of α-alkylated ketones, which possesses the
merit of low waste transformation.[3] Generally, there are several
routes for the synthesis of α-alkylated ketones (Scheme 1):
(a) The metal-catalyzed alkylation of alcohols with alcohols;[4]
(b) The metal-catalyzed alkylation of ketones with alcohols;[5]
(c) The metal-catalyzed one-pot sequential alkylation of alcohols
with alcohols to afford α, α-disubstituted branched ketones.[6]
The processes of these transformations are involved three
steps: Firstly, the aldehydes or ketones are formed by a
dehydrogenation of alcohols; Secondly, aldol-type condensation
takes place to afford the unsaturated carbonyl compounds
which is facilitated by base;[7] Finally, the borrowed hydrogen
removed from the alcohols by the catalysts is added to the C=C
bond to form the desired product.[3a,8]
Scheme 1. Synthesis of α-alkylated ketones via hydrogen borrowing.
direct cross-coupling of alcohols and astonishing achievements
have been made. Apart from iridium-catalyzed cross-coupling
of alcohols,[4,6] different metal-catalyzed alkylation of alcohols
was also well explored. For example, the cross-coupling of
alcohols was realized with Mn,[9] Cu,[10] Ru,[11] Ni,[12] Co,[13] Zr,[14]
Rh,[15] Pd,[16] Au[17] catalysts. In addition to single metal-catalyzed
coupling, the mixed metal catalysts, such as CuÀ Ag,[18] PtÀ Sn,[19]
AgÀ Al,[20] Ru-Ir[21] were also reported.
Until now, great efforts have been devoted to the metal-
catalyzed alkylation of ketones with alcohols[4] and alcohols
with alcohols[5,6] to synthesize α-alkylated ketones. In contrast
to the alkylation of ketones with alcohols, the cross-coupling of
alcohols with alcohols has the advantage of employing the
alcohols as the material, which is cheap and readily available.
Therefore, considerable attention has been focused on the
The development of sustainable, efficient, one-step, and
atom-economical strategies for the transformation of valuable
building blocks with readily available starting materials is a
huge appeal for modern transition metal-catalyzed
methodologies.[3b] Although tremendous efforts had been made
in the development of metal-catalyzed alkylation of alcohols,
however, almost all of which was conducted in organic
solvents.[11–13,18] Therefore, there is still room for improvement in
terms of sustainable and environmentally benign catalytic
methods.
[a] Dr. N. Luo, Y. Zhong, Dr. H. Wen, H. Shui, Prof. Dr. R. Luo
School of Pharmaceutical Sciences, Gannan Medical University
341000 Ganzhou, Jiangxi Province, P. R. China
E-mail: luorenshi2010@163.com
Recently, our group was devoted to the application of
catalytic reactions with iridium complexes catalysts and devel-
Supporting information for this article is available on the WWW under
https://doi.org/10.1002/ejoc.202001550
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Table 1. Optimization of iridium catalysts for the α-alkylation of alcohols.[a]
oped some efficient catalytic methodologies using water as the
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solvent.[22] For example, we had developed the iridium com-
plex-catalyzed N-alkylation of amines with alcohols[22c] and
reductive amination of aldehydes and ketones[22d] in water.
According to our previous work, we have the following findings:
(1) The mechanism of N-alkylation of amines with alcohols went
through the dehydrogenative process of alcohol, which
indicated the iridium catalysts could promote dehydrogenation
of alcohols;[22c] (2) Study on chemoselective transfer hydro-
genation of transformation demonstrated the iridium catalysts
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Entry
Catalyst
Time [h]
3aa:4aa[b]
Yield of 3aa [%])[b]
could realize
a selective reduction of α, β-unsaturated
compounds;[22a] For example, When HCOOH is used as the
hydrogen donor (pH�3), intermediate A is formed through a
four-membered transition state. Similarly, the intermediate B is
formed through a similar four-membered transition state under
basic conditions (Scheme 2). (3) Water is not adverse but helpful
for these iridium-catalyzed transformations.[22] Basing on the
above findings, we envisioned those previous iridium catalysts
should realize the cross-coupling of alcohols in water. Herein,
we describe our findings on iridium complexes as efficient
catalysts for the construction of α-substituted ketones via
hydrogen borrowing of alcohols in water (Scheme 3). In
contrast to organic solvents, water plays an important role in
accelerating the reduction of the unsaturated ketones inter-
mediates.
1
2
3
4
5
6
7
TC-1
TC-2
TC-3
TC-4
TC-5
TC-6
TC-6
–
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24
24
24
24
16
72
72
89:11
87:13
82:18
97:3
94:6
98:2
96:4
51:49
51:49
86
82
78
96
91
97 (92)[c]
94
8[d]
9[d,e]
49
51
–
[a] Reaction conditions: a mixture of 1a (1.1 mmol), 2a (1.0 mmol), t-BuOK
(1.0 mmol), toluene (2 mL), 4 A molecular sieve (40 mg) and Tang’s catalyst
(1.0 mol%) at 110 C for 24 h. [b] Determined by GC-MS and there are
different proportions of fully reduced products in the reactions that are less
than 99% conversion. [c] Yield of isolated product 3aa. [d] No Tang’s
catalyst was used. [e] 1.0 mol% of acetophenone was added.
°
providing the alkylated product 3aa in 86% yield, along with
the unsaturated ketone side product in the percent of 11%
(Table 1, entry 1). Encouraged by this promising result, different
Tang’s catalysts were tested to afford better activities and
chemoselectivities. With TC-2–TC-6 in hand, the compared
experiments were investigated under the standard conditions,
which demonstrated that TC-2 and TC-3 showed almost the
same results with TC-1 (Table 1, entries 2 and 3). However, TC-4
and TC-5 exhibited better activities and selectivities (Table 1,
entries 4 and 5). To our delight, TC-6 was distinguished from
above iridium catalysts, affording the desired product 3aa in
the conversion of 97% and selectivity of 98:2 (Table 1, entry 6).
To explore the details of this catalytic system, control experi-
ments were also conducted. As can be seen in Table 1, the
conversion and selectivity were decreased when the reaction
proceeded for 16 h (entry 7). Surprisingly, the reaction also
happened even without iridium catalysts under standard
conditions, affording the corresponding product 3aa in moder-
ate conversion and chemoselectivitiy (Table 1, entries 8 and 9).
For the reason of this control result, Crabtree’s group proposed
Oppenauer oxidation and Meerwein-Ponndorf-Verley (MPV)
reduction routes in 2010[23a] and few groups also suggested a
similar type of mechanism.[23b,24] In 2013, Xu’s group presented a
valuable work on aldehyde-catalyzed transition metal-free
dehydrative ß-alkylation of methyl carbinols with alcohols.[23e]
Control tests had been conducted (entry 9).
Results and Discussion
Initially, the reaction of benzyl alcohol (1a) and 1-phenylethanol
(2a) was investigated as the model reaction in the presence of
°
TC-1–TC-6 as catalysts and t-BuOK a base in toluene at 110 C
(Table 1). Interestingly, catalyst TC-1 exhibited good activity,
Scheme 2. Possible intermediates under different conditions.
To further improve the reactivity and selectivity of the
catalyst, various reaction parameters were also optimized,
which was summarized in Table 2. As can be seen in Table 2,
strong bases such as t-BuONa, NaOH and KOH gave the desired
products in excellent conversions and selectivities (entries 4–6),
Scheme 3. Construction of α-substituted ketones via hydrogen borrowing of
alcohols.
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introduction of disubstituted electron-donating substrates such
Table 2. Optimization of reaction parameters in the iridium-catalyzed α-
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alkylation of alcohols.[a]
as 1h and 1p resulted in lower activities but the same excellent
chemoselectivities (Table 3, entries 8 and 16). Similarly, 1-
naphthalenylmethanol or 2-naphthalenylmethanol and 2-thio-
phenylmethanol (1q, 1r, and 1s) were also well tolerated
(entries 17–19). Interestingly, aliphatic alcohols did not affect
the activities, but selectivities. For example, when C2H5OH and
C3H7OH were employed as substrates, a bit lower selectivities
were obtained (entries 20 and 21). As for various substituted 1-
phenylethanol, including electron-withdrawing groups (en-
tries 22–28) or electron-donating groups (entries 29–33) at
different positions, the results were similar to the 1-phenyl-
ethanol, providing the α-alkylation ketones over the yields of
86%. Remarkably, 1-phenylpropanol was again tolerated in this
transformation, providing the α-alkylation ketone 3vl in high
yields of 90% (entry 34).
To further exhibit the utility of this catalytic system, the
intramolecular α-alkylation of 1-(2-(hydroxymethyl) phenyl)
ethan-1-ol was explored which was summarized in Table 4.
Notably, the presence of substituent groups such as methoxyl,
methyl, hydroxyl, and fluorine did not affect the intramolecular
cross-coupling, and excellent isolated yields were generally
obtained (entries 2–6).
In order to compare with the TC-6 catalyst, the initial
reaction rates of other Tang catalysts TC-1–TC-5 were studied,
which was summarized in Table 5. Different with TC-6 catalyst,
other Tang catalysts resulted in a small amount of alcohol by-
product 8aa (Table 5).
To better explore the catalytic efficiency of this catalytic
system, we have carried out more detailed monitoring of this
reaction. As shown in Scheme 4, using 0.1 mol% TC-6 as the
catalyst, 38.2% of the raw material was converted in ten
minutes. Over 50% and 99% starting material was converted
after 20 minutes and 60 minutes, respectively.
Entry Base
Solvent
T
Time
[h]
3aa:4aa[b] Yield of 3aa
[%][b]
°
[ C]
1
2
3
4
HCO2Na toluene 110
Na2CO3 toluene 110
K2CO3
t-BuO-
Na
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24
24
24
59:41
86:14
92:8
56
83
90
94
toluene 110
toluene 110
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95:5
5
6
7
8
NaOH
KOH
KOH
KOH
KOH
KOH
KOH
toluene 110
toluene 110
24
24
48
24
6
95:5
93
>99
77
>99:1
80:20
62:38
>99:1
>1:99
>99:1
97:3
THF
DMF
H2O
H2O
H2O
H2O
H2O
80
110
100
100
80
80
80
60
9
>99
23
10[d]
11[e]
6
12
24
12
99(94)[c]
89
12[e,f] KOH
13[g]
KOH
>99:1
>99
[a] Reaction conditions: a mixture of 1a (1.1 mmol), 2a (1.0 mmol), KOH
(1.1 mmol), Solvent (2 mL), and TC-6 (1.0 mol%). [b] Determined by GC-MS
and there are different proportions of fully reduced products in the
reactions that are less than 99% conversion. [c] Yield of isolated product
3aa. [d] No Tang’s catalyst was used but 1.0 mol% of acetophenone was
added, 4aa was afforded in the yield of 23%. [e] 0.1 mol% TC-6 was used.
[f] 0.8 mmol KOH was used. [g] Control experiment were conducted (See
Supporting Information).
but weak bases such as HCO2Na, Na2CO3, and K2CO3 gave lower
conversions and selectivities (entries 1–3). Notably, the KOH
was the best base in this catalytic system, which achieved the
product 3aa in full conversion and >99:1 selectivity (entry 7).
Evaluation of this cross-coupling reaction in common solvents
established water as an optimal medium (entries 6–9). With the
best base KOH and optimal solvent water in hand, further
detailed reaction conditions were screened (entries 10–13). For
example, decreasing the catalyst loading to 0.1 mol% and
Based on the above-detailed monitoring experiments, we
explored the recycling efficiency of the catalyst. Recycling
experiments showed that the catalyst maintained the same
°
lowering the reaction temperature to 80 C showed the same
results with 1.0 mol% catalyst loading and the reaction temper-
°
ature of 100 C (entry 11). Surprisingly, only unsaturated-ketone
4aa was afforded in the yield of 23% when no TC-6 catalyst
but 1.0 mol% of acetophenone was added (entry 10).[23e]
However, decreasing the base loading of KOH to 0.8 equivalent
showcased
a significantly lower yield than 1.0 equivalent
(entry 12). Literature indicated that by adjusting the catalyst
loading or alkali, chemoselective products could be
achieved.[4a,6a] Control experiment, such as benzylideneacetone
4aa as substrate, 1a or 2a as the hydrogen donor, demon-
strated the fast hydrogen transfer reduction of C=C bond of
4aa,[22a] which showcased the high chemoselective synthesis of
α-alkylated ketone products (Table 2, entry 13).
With optimized conditions in hand, the substrate scope of
the iridium-catalyzed α-alkylation of alcohols was examined
(Table 3). In general, all selected benzyl alcohols, with substitu-
ents at various positions (1b–1o), or having electron-rich
(entries 1–8) and electron-poor (entries 9–15) groups, cross-
coupled with 1-phenylethanol successfully to afford α-alkylation
ketones in excellent yields and chemoselectivities. However, the
Scheme 4. Time-conversion experiments.
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Table 3. Iridium-catalyzed α-alkylation of 1-phenylethanol and 1-phenyl-
propanol using primary alcohols.[a]
Table 3. continued
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2
3
4
5
6
7
Entry
1
2
Time
[h]
3:4[b]
Yield
[%][c]
Entry
1
2
Time
[h]
3:4[b]
Yield
[%][c]
8
9
20
21
22
23
C2H5OH
C3H7OH
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18
12
10
97:3
95:5
(3ta) 90
(3ua) 88
1
2
12
16
>99:1 (3aa) 94
>99:1 (3ba)92
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12
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14
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3
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5
6
7
14
16
14
13
15
>99:1 (3ca) 93
>99:1 (3da) 90
>99:1 (3ea) 94
>99:1 (3fa) 92
>99:1 (3ga) 90
>99:1 (3ab) 95
CH3OH
CH3OH
CH3OH
CH3OH
97:3
(3vb) 91
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25
26
12
10
14
>99:1 (3vc) 92
98:2
(3vd) 93
>99:1 (3ve) 94
8
18
12
10
>99:1 (3ha) 88
>99:1 (3ia) 93
>99:1 (3ja) 91
9
27
28
CH3OH
14
16
96:4
95:5
(3vf) 90
(3uf) 89
10
C3H7OH
11
12
13
10
12
16
>99:1 (3ka) 95
>99:1 (3la) 94
>99:1 (3ma) 90
29
30
31
CH3OH
CH3OH
CH3OH
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16
18
96:4
95:5
96:4
(3vg) 91
(3vh) 89
(3vi) 90
14
15
16
15
18
18
>99:1 (3na) 89
>99:1 (3oa) 87
>99:1 (3pa) 90
32
33
34
CH3OH
C3H7OH
CH3OH
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16
24
95:5
95:5
96:4
(3vj) 88
(3uk) 86
(3vl) 90
17
16
98:2
99:1
(3qa) 91
(3ra) 93
[a] Reaction conditions: a mixture of 1 (1.1 mmol), 2 (1.0 mmol), KOH
(1.1 mmol), H2O (2.0 mL) and TC-6 (0.1 mol%) at 80 C. [b] Determined by
GC-MS. [c] Yield of isolated product 3.
18
19
16
18
°
>99:1 (3sa) 92
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Table 4. Iridium-catalyzed
intramolecular
α-alkylation
of
1-(2-
1
2
(hydroxymethyl) phenyl) ethan-1-ol.[a]
3
4
5
6
7
8
9
Entry
1
5
Time /h
12
6:7[b]
Yield [%][c]
(6a) 93
>99:1
Scheme 5. Recycling experiments.
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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
2
3
16
14
>99:1
>99:1
(6b)91
(6c) 90
4
16
>99:1
(6d) 94
Scheme 6. Scale-up experiment.
5
6
15
18
99:1
97:3
(6e)91
(6f)90
tion (Scheme 7). The key question is what role water plays in
this reaction. Such a problem plays a key role in the design and
synthesis of future catalysts. Firstly, cross-coupling of deuter-
ated 4-methylbenzyl alcohol and 1-phenylethanol under
standard conditions afforded
a different deuterated 3da
(Scheme 7a), where the deuterium was marked as an approx-
imately 62% ratio in the β-positions of the carbonyl group,
which indicated that the hydrogen of β-positions is mainly
derived from the primary alcohols. Surprisingly, performing the
cross-coupling reaction under D2O also afforded deuterated
3da product (Scheme 7b), where deuterium was completely
incorporated in the α- and β-positions of carbonyl group as
30% and 10% respectively. It shows that water participates in
the reduction process of hydrogen borrowing, which may also
explain that water can accelerate the transformation.
Based on the experimental results and deuterated evidence,
we put forward a possible mechanism (Scheme 8):[22] Firstly,
alkoxy iridium species Int-I and Int-I’ are formed through the
reaction of TC-6 and alcohols under the action of KOH.
Subsequently, aldehydes A, ketones B and iridium hydride Int-
III.[5a,b] are afforded by β-hydrogen elimination of alkoxy iridium
species Int-I and Int-I’. Then A and B intermediates undergo
aldol-condensation with each other to achieve unsaturated
[a] Reaction conditions: a mixture of 5 (1.0 mmol), KOH (1.1 mmol), H2O
(2.0 mL) and TC-6 (0.1 mol%) at 80 C. [b] Determined by GC-MS. [c] Yield of
isolated.
°
Table 5. Time-conversion experiments with different Tang’s catalysts.
Cat
Time [min]
2a [%]
3aa [%]
4aa [%]
8aa [%]
TC-1
10
20
10
20
10
20
10
20
10
20
87.1
76.3
81.6
69.7
90.7
84.3
72.7
51.4
88.6
79.8
10.5
19.5
14.9
24.9
6.5
11.3
25.6
46.1
8.6
1.3
2.4
2.2
3.7
1.4
2.5
0.8
1.4
0.5
1.0
1.1
1.8
1.3
1.7
1.4
1.9
0.9
1.1
2.3
2.9
TC-2
TC-3
TC-4
TC-5
16.3
catalytic efficiency when it was reused. Satisfactorily, the
catalytic efficiency remained unchanged even after five cycles
(Scheme 5).
A scale-up survey of this catalytic system was performed to
explore the potential application of this cross-coupling reaction.
Gratifyingly, when the amount was expanded to gram scale, an
excellent yield of 91% and selectivity of >99:1 were achieved
under the standard conditions (Scheme 6).
With the results of iridium-catalyzed α-alkylation of alcohols
in hand, detailed experiments were also performed to gain
insight into the mechanism of this cross-coupling transforma-
Scheme 7. Deuterium labeling studies for the iridium-catalyzed α-alkylation
of alcohols.
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Conclusion
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2
In summary, we have reported an iridium complexes-catalyzed
cross-coupling of alcohols via hydrogen borrowing, affording a
series of α-alkylated ketones in high yield (86%–95%) and
chemoselectivities (>99:1). This methodology has the advan-
tages of low catalyst loading (0.1 mol%) and environmentally
benign water as the solvent. Remarkably, a gram-scale experi-
ment demonstrates this methodology of iridium-catalyzed
cross-coupling of alcohols has potential application in the
practical synthesis of α-alkylated ketones.
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Experimental Section
General Information. Reagents were purchased from commercial
sources. 1H and 13C Nuclear Magnetic Resonance (NMR) spectra
were recorded on Bruker AVANCE NEO 400 MHz NMR spectrom-
eters. Chemical shifts (δ) are reported in ppm from internal
tetramethylsilane or the central CDCl3 resonance (δ=7.26 ppm) for
1H NMR and relative to the central CDCl3 resonance (δ=77.16 ppm)
for 13C NMR spectroscopy. The melting points were determined on
WRR melting point apparatus. The conversion was monitored by
thin-layer chromatography (TLC). Flash column chromatography
was performed over silica gel (200–300 mesh). GC analyses were
performed on an Agilent GC-7900.
Scheme 8. Proposed reaction mechanism.
ketones 4, which coordinates with iridium hydride Int-III to
generate Int-IV. Then addition of C=C bond of unsaturated
ketones to obtain carbanion-iridium species Int-V. Finally, the
target products are obtained and alkoxy iridium species Int-I
and Int-I’ recycle under the action of alcohols.[25d,e] Simulta-
neously, the iridium hydride Int-III decomposes into alkoxy
iridium species Int-I and Int-I’ under the action of alcohol 1a
and 2a, which releases one molecule of hydrogen respectively.
According to the deuterated water experiment, the deuterated
products are achieved. Based on this, we speculate that a
proton exchange is happening between water and iridium
hydride Int-III, which accelerates this iridium-catalyzed α-
alkylation transformation.[25]
General Procedure for Synthesis of ketones
In a 10 mL Schlenk tube, a mixture of 1 (1.1 mmol), 2 (1.0 mmol),
KOH (1.1 mmol), H2O (2.0 mL), and TC-6 (1.0 mol%) was reacted at
°
80 C protected by nitrogen. After completion of the reaction, the
mixture was extracted with ethyl acetate (3×10.0 mL). The
combined ethyl acetate layer was then dried over magnesium
sulfate and concentrated in vacuum. And the resulting crude
product was purified by silica gel chromatography using a mixture
of EtOAc/petroleum ether (1/50) as eluent to afford the ketone
products.
The proposed mechanism was supported by control experi-
ments (Scheme 9). For example, with unsaturated ketones as
substrate, the product 3aa was afforded in the yield of 95% by
employing alcohols 1a or 2a as hydrogen donors under
standard conditions.
Procedure for Gram-Scale Hydrogen transfer reaction. In
a
100 mL Schlenk tube, a mixture of benzyl alcohol 1a (11.0 mmol),
Phenylethanol 2a (10.0 mmol), KOH (11.0 mmol), H2O (20.0 mL) and
°
TC-6 (0.1 mol%) reacted at 80 C protected by nitrogen. After
completion of the reaction, the mixture was extracted with ethyl
acetate (3×50 mL). The combined ethyl acetate layer was then
dried over magnesium sulfate and concentrated in vacuum. And
the resulting crude product was purified by silica gel chromatog-
raphy using a mixture of EtOAc/petroleum ether (1/50) as eluent to
afford the 1,3-Diphenyl-propan-1-one 3aa (2.1 g, 91% yield).
General Procedure for Catalytic cycle
In a 10.0 mL Schlenk tube, a mixture of 1a (1.1 mmol), 2a
(1.0 mmol), KOH (1.1 mmol), H2O (2.0 mL), and TC-6 (1.0 mol%) was
°
reacted at 80 C protected by nitrogen. After completion of the
reaction, the mixture was extracted with EtOAc (3×10.0 mL). The
combined EtOAc layer was determined by GC-MS, and the water
layer was reserved for the next time.
1,3-Diphenyl-propan-1-one (3aa):[26] Colorless oil. Yield: 197.5 mg,
1
94%. H NMR (400 MHz, CDCl3) δ 8.00–7.98 (m, 2H), 7.62–7.55 (m,
1H), 7.50–7.46 (m, 2H), 7.35–7.24 (m, 5H), 3.34 (t, J=8.4, 2H), 3.10 (t,
2H); 13C NMR (100 MHz, CDCl3) δ 199.3, 141.3, 136.9, 133.1, 128.6,
128.6, 128.5, 128.1, 126.2, 40.5, 30.1.
Scheme 9. Transfer hydrogenation of 4aa with alcohols.
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1-Phenyl-3-o–tolyl-propan-1-one (3ba):[27] Colorless oil. Yield:
206.2 mg, 92%. H NMR (400 MHz, CDCl3) δ 8.01 (d, J=7.9 Hz, 2H),
7.60 (t, J=7.4 Hz, 1H), 7.50 (t, J=7.6 Hz, 2H), 7.26–7.14 (m, 4H), 3.29
(t, J=8.0 Hz, 2H), 3.10 (t, J=8.0 Hz, 2H), 2.40 (s, 3H); 13C NMR
(100 MHz, CDCl3) δ 199.4, 139.4, 136.9, 136.0, 133.1, 130.4, 128.8,
128.7, 128.1, 126.4, 126.2, 39.1, 27.5, 19.4.
3-(4-Fluoro-phenyl)-1-phenyl-propan-1-one (3ka):[31] Colorless oil.
Yield: 216.7 mg, 95%.1H NMR (400 MHz, CDCl3) δ 7.98 (d, J=7.9 Hz,
2H), 7.58 (t, J=7.4 Hz, 1H), 7.48 (t, J=7.6 Hz, 2H), 7.23 (dd, J=8.2,
5.6 Hz, 2H), 7.00 (t, J=8.6 Hz, 2H), 3.31 (t, J=7.6 Hz, 2H), 3.07 (t, J=
7.5 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 199.0, 162.6, 160.2, 136.8,
133.2, 129.9 (d, J=7.9 Hz), 128.7, 128.0, 115.3 (d, J=80.0 Hz), 40.4,
29.3.
1
2
3
4
5
6
7
8
9
1
1-Phenyl-3-m–tolyl-propan-1-one (3ca):[27] Colorless oil. Yield:
1
208.4 mg, 93%. H NMR (400 MHz, CDCl3) δ 8.00 (d, J=8.0 Hz, 2H),
3-(4-Chloro-phenyl)-1-phenyl-propan-1-one (3la):[5a] Colorless oil.
Yield: 229.5 mg, 94%.1H NMR (400 MHz, CDCl3) δ 7.97 (d, J=7.9 Hz,
2H), 7.58 (t, J=7.3 Hz, 1H), 7.48 (t, J=7.6 Hz, 2H), 7.28 (d, J=8.3 Hz,
2H), 7.21 (d, J=8.3 Hz, 2H), 3.30 (t, J=7.5 Hz, 2H), 3.07 (t, J=7.5 Hz,
2H); 13C NMR (100 MHz, CDCl3) δ 198.9, 139.8, 136.8, 133.2, 131.9,
129.9, 128.7, 128.6, 128.0, 40.2, 29.4.
7.59 (br, 1H), 7.49 (t, J=7.6 Hz, 2H), 7.23 (t, J=7.5 Hz, 1H), 7.11–7.05
(m, 3H), 3.33 (t, J=8.0 Hz, 2H), 3.07 (t, J=8.0 Hz, 2H), 2.37 (s, 3H);
13C NMR (100 MHz, CDCl3) δ 199.3, 141.3, 138.1, 136.9, 133.1, 129.3,
128.6, 128.5, 128.1, 126.9, 125.4, 40.6, 30.1, 21.4.
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
1-Phenyl-3-p–tolyl-propan-1-one (3da):[28] Colorless oil. Yield:
1
201.7 mg, 90%. H NMR (400 MHz, CDCl3) δ 8.00 (d, J=7.9 Hz, 2H),
3-(2-Bromo-phenyl)-1-phenyl-propan-1-one (3ma):[29] Colorless oil.
Yield: 259.3 mg, 90%.1H NMR (400 MHz, CDCl3) δ 8.00 (t, J=6.8 Hz,
2H), 7.57 (d, J=7.7 Hz, 2H), 7.48 (t, J=7.6 Hz, 2H), 7.34 (br, 1H), 7.27
(br, 1H), 7.11 (t, J=7.6 Hz, 1H), 3.34 (t, J=8.0 Hz, 2H), 3.21 (t, J=
7.8 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 199.0, 140.6, 136.8, 133.2,
132.9, 130.8, 128.6, 128.1, 128.0, 127.7, 124.4, 38.6, 30.8.
7.58 (d, J=7.4 Hz, 1H), 7.49 (t, J=7.6 Hz, 2H), 7.18 (q, J=8.0 Hz, 4H),
3.33 (t, J=7.7 Hz, 2H), 3.08 (t, J=7.7 Hz, 2H), 2.37 (s, 3H); 13C NMR
(100 MHz, CDCl3) δ 199.4, 138.2, 136.9, 135.7, 133.1, 129.2, 128.6,
128.3, 128.1, 40.6, 29.8, 21.1.
3-(2-Methoxy-phenyl)-1-phenyl-propan-1-one (3ea):[29] Colorless
1
oil. Yield: 225.9 mg, 94%. H NMR (400 MHz, CDCl3) δ 8.02 (d, J=
3-(3-Bromo-phenyl)-1-phenyl-propan-1-one (3na):[31] White solid.
1
°
8.0 Hz, 2H), 7.58 (t, J=7.3 Hz, 1H), 7.48 (t, J=7.6 Hz, 2H), 7.26–7.23
(m, 2H), 6.99–6.87 (m, 2H), 3.87 (s, 3H), 3.31 (t, J=8.0 Hz, 2H), 3.10
(t, J=8.0 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 200.0, 157.6, 137.0,
132.9, 130.2, 129.6, 128.6, 128.2, 127.6, 120.6, 110.3, 55.2, 39.0, 25.8.
Yield: 256.4 mg, 89%, mp 69–70 C. H NMR (400 MHz, CDCl3) δ 8.00
(d, J=7.6 Hz, 2H), 7.57 (d, J=7.6 Hz, 2H), 7.48 (t, J=7.3 Hz, 2H), 7.34
(d, J=7.5 Hz, 1H), 7.27 (t, J=7.3 Hz, 1H), 7.10 (t, J=7.6 Hz, 1H), 3.34
(t, J=7.3 Hz, 2H), 3.21 (t, J=7.3 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ
198.9, 140.6, 136.7, 133.2, 132.9, 130.8, 128.6, 128.1, 128.0, 127.7,
124.4, 38.6, 30.8.
3-(3-Methoxy-phenyl)-1-phenyl-propan-1-one (3fa):[29] Colorless
1
oil. Yield: 221.0 mg, 92%. H NMR (400 MHz, CDCl3) δ 7.99 (d, J=
7.7 Hz, 2H), 7.58 (t, J=7.3 Hz, 1H), 7.48 (t, J=7.6 Hz, 2H), 7.26–7.23
(m, 1H), 6.88–6.76 (m, 3H), 3.82 (s, 3H), 3.33 (t, J=8.0 Hz, 2H), 3.08
(t, J=7.7 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 199.2, 159.8, 142.9,
136.9, 133.1, 129.5, 128.6, 128.1, 120.8, 114.3, 111.4, 55.2, 40.38 (s),
30.2.
3-(4-Bromo-phenyl)-1-phenyl-propan-1-one (3oa):[5a] Colorless oil.
Yield: 250.6 mg, 87%. 1H NMR (400 MHz, CDCl3) δ 7.97 (d, J=8.0 Hz,
2H), 7.58 (t, J=7.4 Hz, 1H), 7.53–7.38 (m, 4H), 7.15 (d, J=8.2 Hz, 2H),
3.30 (t, J=7.5 Hz, 2H), 3.05 (t, J=7.5 Hz, 2H); 13C NMR (100 MHz,
CDCl3) δ 198.8, 140.3, 136.8, 133.2, 131.6, 130.3, 128.7, 128.0, 119.9,
40.1, 29.4.
3-(4-Methoxy-phenyl)-1-phenyl-propan-1-one (3ga):[4] Colorless
1
oil. Yield: 216.3 mg, 90%. H NMR (400 MHz, CDCl3) δ 7.98 (d, J=
3-Benzo[1,3]dioxol-5-yl-1-phenyl-propan-1-one (3pa):[7b] Colorless
1
7.9 Hz, 2H), 7.58 (t, J=7.4 Hz, 1H), 7.48 (t, J=7.6 Hz, 2H), 7.20 (d, J=
8.4 Hz, 2H), 6.87 (d, J=8.5 Hz, 2H), 3.81 (s, 3H), 3.30 (t, J=7.7 Hz,
2H), 3.04 (t, J=7.6 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 199.4, 158.0,
136.9, 133.3, 133.1, 129.4, 128.6, 128.1, 114.0, 55.3, 40.7, 29.3.
oil. Yield: 228.7 mg, 90%. H NMR (400 MHz, CDCl3) δ 7.98 (d, J=
7.9 Hz, 2H), 7.58 (t, J=7.4 Hz, 1H), 7.48 (t, J=7.6 Hz, 2H), 6.77–6.71
(m, 3H), 5.94 (s, 2H), 3.28 (t, J=7.6 Hz, 2H), 3.01 (t, J=7.6 Hz, 2H);
13C NMR (100 MHz, CDCl3) δ 199.2, 147.7, 145.8, 136.9, 135.1, 133.1,
128.6, 128.0, 121., 108.9, 108.3, 100.8, 40.7, 29.9.
3-(2,4-Dimethoxy-phenyl)-1-phenyl-propan-1-one (3ha):[30] Color-
1
less oil. Yield: 237.7 mg, 88%. H NMR (400 MHz, CDCl3) δ 8.00 (d,
3-Naphthalen-1-yl-1-phenyl-propan-1-one (3qa):[27] Colorless oil.
Yield: 234.1 mg, 91%. 1H NMR (400 MHz, CDCl3) δ 8.11 (d, J=8.2 Hz,
1H), 8.00 (d, J=7.9 Hz, 2H), 7.93 (d, J=7.8 Hz, 1H), 7.82–7.76 (m,
1H), 7.62–7.51 (m, 3H), 7.51–7.41 (m, 4H), 3.60 (t, J=7.8 Hz, 2H),
3.47 (t, J=7.8 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 199.3, 137.4,
136.9, 134.0, 133.2, 131.8, 129.0, 128.7, 128.1, 127.1, 126.2, 126.1,
125.7, 125.7, 123.8„ 39.8, 27.3.
J=8.0 Hz, 2H), 7.57 (t, J=7.4 Hz, 1H), 7.47 (t, J=7.6 Hz, 2H), 7.13 (d,
J=8.1 Hz, 1H), 6.51–6.40 (m, 2H), 3.82 (d, J=4.0 Hz, 6H), 3.6 (t, J=
7.6 Hz, 2H), 3.01 (t, J=7.6 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ
200.2, 159.5, 158.4, 137.0, 132.9, 130.4, 128.5, 128.1, 121.9, 103.9,
98.6, 55.4, 55.2, 39.2, 25.2.
3-(2-Fluoro-phenyl)-1-phenyl-propan-1-one (3ia):[29] Colorless oil.
Yield: 212.1 mg, 93%. 1H NMR (400 MHz, CDCl3) δ 7.99 (d, J=8.0 Hz,
2H), 7.58 (dd, J=10.7, 4.0 Hz, 1H), 7.48 (t, J=7.6 Hz, 2H), 7.30 (t, J=
7.3 Hz, 1H), 7.22 (dd, J=13.9, 6.8 Hz, 1H), 7.12–7.02 (m, 2H), 3.33 (t,
J=7.6 Hz, 2H), 3.13 (t, J=7.6 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ
199.0, 162.5, 160.1, 136.8, 133.1, 131.0 (d, J=5.0 Hz), 128.6, 128.1 (d,
J=8.0 Hz), 128.0 (d, J=4.0 Hz), 124.1 (d, J=3.6 Hz), 115.3 (d, J=
80.0 Hz), 38.9, 24.0 (d, J=2.3 Hz).
3-Naphthalen-2-yl-1-phenyl-propan-1-one (3ra):[31] White solid.
1
°
Yield: 241.9 mg, 93%, mp 60–61 C. H NMR (400 MHz, CDCl3) δ 8.02
(d, J=7.8 Hz, 2H), 7.84 (t, J=7.8 Hz, 3H), 7.74 (s, 1H), 7.60 (t, J=
7.3 Hz, 1H), 7.53–7.42 (m, 5H), 3.43 (t, J=7.6 Hz, 2H), 3.28 (t, J=
7.5 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 199.2, 138.8, 136.9, 133.7,
133.1, 132.1, 128.7, 128.1, 128.1, 127.6, 127.5, 127.2, 126.6, 126.1,
125.4, 40.4, 30.3.
3-(3-Fluoro-phenyl)-1-phenyl-propan-1-one (3ja):[29] Colorless oil.
Yield: 207.6 mg, 91%. 1H NMR (400 MHz, CDCl3) δ 7.99 (d, J=7.9 Hz,
2H), 7.59 (t, J=7.4 Hz, 1H), 7.48 (t, J=7.7 Hz, 2H), 7.28 (dd, J=14.1,
7.8 Hz, 1H), 7.06 (d, J=7.6 Hz, 1H), 6.99 (d, J=10.0 Hz, 1H), 6.92–
6.90 (m, 1H), 3.33 (t, J=7.6 Hz, 2H), 3.10 (t, J=7.6 Hz, 2H); 13C NMR
(100 MHz, CDCl3) δ 198.8, 164.2, 161.7, 143.9 (d, J=7.3 Hz), 136.8,
133.2, 130.0 (d, J=8.5 Hz), 128.6 (d, J=5.7 Hz), 124.1 (d, J=2.8 Hz),
115.3 (d, J=80.0 Hz), 113.0 (d, J=84.0 Hz), 40.0, 29.8 (d, J=1.5 Hz).
1-Phenyl-3-thiophen-2-yl-propan-1-one (3sa):[33] Colorless oil.
Yield: 198.8 mg, 92%. 1H NMR (400 MHz, CDCl3) δ 8.00 (d, J=7.6 Hz,
2H), 7.59 (t, J=7.2 Hz, 1H), 7.49 (t, J=7.3 Hz, 2H), 7.16 (d, J=4.7 Hz,
1H), 7.00–6.83 (m, 2H), 3.41–3.38 (m, 2H), 3.36–3.30 (m, 2H); 13C
NMR (100 MHz, CDCl3) δ 198.6, 143.9, 136.7, 133.2, 128.7, 128.1,
126.9, 124.7, 123.4, 40.6, 24.2.
1-Phenyl-butan-1-one (3ta):[34] Colorless oil. Yield: 133.3 mg, 90%.
1H NMR (400 MHz, CDCl3) δ 7.93 (d, J=7.7 Hz, 2H), 7.51 (t, J=7.3 Hz,
1H), 7.41 (t, J=7.5 Hz, 2H), 2.91 (t, J=7.3 Hz, 2H), 1.81–1.69 (m, 2H),
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0.98 (t, J=7.5 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 200.2, 137.1,
132.8, 128.5, 128.0, 40.4, 17.7, 13.9.
(m, 2H), 1.18–1.09 (m, 3H); 13C NMR (100 MHz, CDCl3) δ 199.3, 163.2,
130.1, 129.9, 113.6, 55.31 (s), 31.3, 8.3.
1
2
3
4
5
1-Phenyl-pentan-1-one (3ua):[35] Colorless oil. Yield: 142.6 mg,
1-m-Tolyl-propan-1-one (3vi):[43] Colorless oil. Yield: 133.3 mg,
1
1
88%. H NMR (400 MHz, CDCl3) δ 7.96 (d, J=7.8 Hz, 2H), 7.53 (t, J=
90%. H NMR (400 MHz, CDCl3) δ 7.78–7.70 (m, 2H), 7.37–7.27 (m,
7.3 Hz, 1H), 7.44 (t, J=7.6 Hz, 2H), 2.95 (t, J=7.4 Hz, 2H), 1.78–1.67
(m, 2H), 1.46–1.35 (m, 2H), 0.95 (t, J=7.4 Hz, 3H); 13C NMR (100 MHz,
CDCl3) δ 200.5, 137.1, 132.8, 128.5, 128.0, 38.3, 26.5, 22.5, 13.9.
2H), 2.96 (q, J=7.2 Hz, 2H), 2.39 (s, 3H), 1.21 (t, J=7.3 Hz, 3H); 13C
NMR (100 MHz, CDCl3) δ 200.9, 138.2, 136.9, 133.6, 128.5, 128.4,
125.2, 31.77 (s), 21.3, 8.3.
6
7
8
9
1-(4-Fluoro-phenyl)-3-phenyl-propan-1-one (3ab):[27] Colorless oil.
Yield: 216.7 mg, 95%. 1H NMR (400 MHz, CDCl3) δ 7.97 (d, J=8.0 Hz,
2H), 7.58 (t, J=7.4 Hz, 1H), 7.52–7.39 (m, 4H), 7.15 (d, J=8.2 Hz, 2H),
3.30 (t, J=7.5 Hz, 2H), 3.05 (t, J=7.5 Hz, 2H); 13C NMR (100 MHz,
CDCl3) δ 197.6, 167.0, 164.5, 141.1, 133.30 (d, J=3.0 Hz), 130.7 (d,
J=9.3 Hz), 128.5 (d, J=14.7 Hz), 126.20 (s), 115.7 (d, J=80.0), 40.4
30.1.
1-(4-Ethyl-phenyl)-propan-1-one (3vj):[43] Colorless oil. Yield:
142.7 mg, 88%. H NMR (400 MHz, CDCl3) δ 7.90 (d, J=8.0 Hz, 1H),
7.27 (d, J=7.9 Hz, 1H), 2.97 (q, J=7.2 Hz, 1H), 2.70 (q, J=7.6 Hz,
1H), 1.30–1.18 (m, 3H); 13C NMR (100 MHz, CDCl3) δ 200.5, 149.7,
134.7, 128.2, 128.0, 31.6, 28.9, 15.2, 8.3.
1
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
1-(4-Hydroxy-phenyl)-pentan-1-one (3uk):[44] White solid. Yield:
1
°
153.2 mg, 86%, mp 63–64 C. H NMR (400 MHz, CDCl3) δ 8.41 (s,
1-(4Fluoro-phenyl)-propan-1-one (3vb):[36] Yellow oil. Yield:
138.4 mg, 91%.1H NMR (400 MHz, CDCl3) δ 7.94 (dd, J=7.4, 6.6 Hz,
2H), 7.07 (t, J=8.5 Hz, 2H), 2.93 (q, J=7.2 Hz, 2H), 1.17 (t, J=7.3 Hz,
3H); 13C NMR (100 MHz, CDCl3) δ 199.0, 166.8, 164.3, 133.3 (d, J=
3.0 Hz), 130.5 (d, J=9.2 Hz), 115.5 (d, J=80.0 Hz), 31.6, 8.1.
1H), 7.94 (d, J=8.5 Hz, 2H), 7.00 (d, J=8.2 Hz, 2H), 2.97 (t, J=7.5 Hz,
2H), 1.80–1.69 (m, 2H), 1.42 (dd, J=14.9, 7.4 Hz, 2H), 0.95 (t, J=
7.3 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 201.7, 161.5, 131.0, 129.2,
115.7, 38.1, 27.1, 22.5, 13.9.
2-Methyl-1-phenyl-propan-1-one (3vl):[45] Colorless oil. Yield:
1-(3-Fluoro-phenyl)-propan-1-one (3vc):[37] Colorless oil. Yield:
133.2 mg, 90%. H NMR (400 MHz, CDCl3) δ 7.95 (d, J=7.8 Hz, 2H),
1
1
139.9 mg, 92%. H NMR (400 MHz, CDCl3) δ 7.72 (d, J=7.7 Hz, 1H),
7.52 (t, J=7.3 Hz, 1H), 7.43 (t, J=7.5 Hz, 2H), 3.54 (dt, J=13.6,
6.8 Hz, 1H), 1.20 (d, J=7.0 Hz, 6H); 13C NMR (100 MHz, CDCl3) δ
204.4, 136.2, 132.8, 128.6, 128.3, 35.3, 19.1.
7.61 (d, J=9.5 Hz, 1H), 7.45–7.37 (m, 1H), 7.26–7.18 (m, 1H), 2.96 (q,
J=7.2 Hz, 2H), 1.20 (t, J=7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ
199.4 (d, J=2.0 Hz), 164.1, 161.6, 139.0 (d, J=6.1 Hz), 130.2 (d, J=
7.6 Hz), 123.7 (d, J=3.0 Hz), 119.8 (d, J=80.0 Hz), 114.6 (d, J=
80.0 Hz), 31.9, 8.1.
Indan-1-one (6a):[46] White solid. Yield: 122.9 mg, 93%, mp 40–
1
°
41 C. H NMR (400 MHz, CDCl3) δ 7.78 (d, J=7.7 Hz, 1H), 7.60 (t, J=
7.4 Hz, 1H), 7.50 (d, J=7.7 Hz, 1H), 7.39 (t, J=7.4 Hz, 1H), 3.19–3.13
(m, 2H), 2.74–2.67 (m, 2H); 13C NMR (100 MHz, CDCl3) δ 207.1, 155.2,
137.1), 134.6, 127.3, 126.7, 123.7, 36.2, 25.8.
1-(2,4-Difluoro-phenyl)-propan-1-one (3vd):[38] Yellow oil. Yield:
1
158.2 mg, 93%. H NMR (400 MHz, CDCl3) δ 7.96–7.82 (m, 1H), 6.91
(t, J=8.2 Hz, 1H), 6.87–6.74 (m, 1H), 2.98–2.89 (m, 2H), 1.16 (t, J=
7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 197.4 (d, J=4.6 Hz), 166.8
(d, J=12.2 Hz), 164.3 (d, J=12.3 Hz), 164.0 (d, J=12.5 Hz), 161.4 (d,
J=12.5 Hz), 132.5 (dd, J=10.5, 4.5 Hz), 122.1 (dd, J=13.6, 3.6 Hz),
112.0 (dd, J=21.4, 3.4 Hz), 104.6 (dd, J=80.0, 3.4 Hz), 36.6 (d, J=
7.7 Hz), 7.8 (d, J=2.1 Hz).
6-Methoxy-indan-1-one (6b):[47] Colorless solid. Yield: 147.5 mg,
1
°
91%, mp 105–106 C. H NMR (400 MHz, CDCl3) δ 7.37 (d, J=9.1 Hz,
1H), 7.19 (d, J=6.6 Hz, 2H), 3.84 (s, 3H), 3.07 (t, J=4.0 Hz, 2H), 2.71
(t, J=4.0 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 207.0, 159.3, 148.0,
138.2, 127.4, 124.0, 104.9, 55.6, 37.0, 25.1.
5-Methyl-indan-1-onee (6c):[48] Colorless solid. Yield: 131.6 mg,
1-(3-Chloro-phenyl)-propan-1-one (3ve):[39] White solid. Yield:
1
°
90%, mp 94–95 C. H NMR (400 MHz, CDCl3) δ 7.66 (d, J=7.8 Hz,
1
°
157.9 mg, 94%, mp 44–45 C. H NMR (400 MHz, CDCl3) δ 7.92 (s,
1H), 7.28 (s, 1H), 7.18 (d, J=7.8 Hz, 1H), 3.10 (t, J=4.0 Hz, 2H), 2.66
(t, J=4.0 Hz, 2H), 2.45 (s, 3H); 13C NMR (100 MHz, CDCl3) δ 206.7,
155.7, 145.8, 134.8, 128.6, 127.0, 123.5, 36.4, 25.6, 22.1.
1H), 7.83 (d, J=7.7 Hz, 1H), 7.52 (d, J=7.9 Hz, 1H), 7.40 (t, J=7.8 Hz,
1H), 2.98 (q, J=7.2 Hz, 2H), 1.22 (t, J=7.2 Hz, 3H); 13C NMR
(100 MHz, CDCl3) δ 199.4, 138.4, 134.9, 132.8, 129.9, 128.1, 126.0,
31.9, 8.1.
4-Fluoro-indan-1-one (6d):[49] White solid. Yield: 141.0 mg, 94%,
1
°
mp 61–62 C. H NMR (400 MHz, CDCl3) δ 7.62–7.50 (m, 1H), 7.27 (t,
1-(4-Chloro-phenyl)-propan-1-one (3vf):[40] White solid. Yield:
J=6.4 Hz, 1H), 6.98 (t, J=8.7 Hz, 1H), 3.17 (t, J=4.0 Hz, 2H), 2.73 (t,
J=4.0 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 203.2, 160.4, 157.4 (d,
J=2.4 Hz), 136.6 (d, J=8.3 Hz), 124.9 (d, J=12.9 Hz), 122.5 (d, J=
4.2 Hz), 114.2 (d, J=19.3 Hz), 36.8, 25.8 (d, J=1.3 Hz).
1
°
151.2 mg, 90%, mp 35–36 C. H NMR (400 MHz, CDCl3) δ 7.89 (d,
J=8.0 Hz, 2H), 7.48–7.36 (m, 2H), 2.97 (q, J=7.2 Hz, 2H), 1.22 (t, J=
7.2 Hz, 3H); 13C NMR (100 MHz, CDCl3) δ 199.5, 139.2, 135.2, 129.4,
128.8, 31.8, 8.1.
4-Hydroxy-indan-1-one (6e):[50] White solid. Yield: 134.8 mg, 91%,
1-(4-Chloro-phenyl)-pentan-1-one (3uf):[41] White solid. Yield:
1
°
mp 154–155 C. H NMR (400 MHz, DMSO) δ 10.02 (s, 1H), 7.23 (t,
1
°
174.5 mg, 89%, mp 32–33 C. H NMR (400 MHz, CDCl3) δ 7.89 (d,
J=7.6 Hz, 1H), 7.08 (t, J=6.7 Hz, 2H), 2.93 (t, J=4.0 Hz, 2H), 2.59 (d,
J=4.0 Hz, 2H); 13C NMR (100 MHz, DMSO) δ 207.1, 155.6, 142.3,
138.8, 129.1, 120.2, 113.7, 36.2, 22.8.
J=8.3 Hz, 2H), 7.42 (d, J=8.3 Hz, 2H), 2.93 (t, J=7.4 Hz, 2H), 1.76–
1.66 (m, 2H), 1.40 (dd, J=15.0, 7.5 Hz, 2H), 0.95 (t, J=7.4 Hz, 3H); 13
C
NMR (100 MHz, CDCl3) δ 199.2, 139.2, 135.4, 129.5, 128.8, 38.3), 26.4,
22.4, 13.9.
5-Hydroxy-indan-1-one (6f):[51] White solid. Yield: 133.3 mg, 90%,
1
°
mp 175–176 C. H NMR (400 MHz, DMSO) δ 10.48 (s, 1H), 7.48 (d,
1-(3-Methoxy-phenyl)-propan-1-one (3vg):[40] Colorless oil. Yield:
J=8.3 Hz, 1H), 6.88–6.77 (m, 2H), 2.97 (t, J=8.0 Hz, 2H), 2.52 (t, J=
4.0 Hz, 2H); 13C NMR (100 MHz, DMSO) δ 204.5, 164.1, 158.7, 129.1,
125.3, 116.2, 112.5, 36.4, 25.7.
1
149.3 mg, 91%. H NMR (400 MHz, CDCl3) δ 7.51 (d, J=7.7 Hz, 1H),
7.47 (s, 1H), 7.32 (t, J=7.9 Hz, 1H), 7.06 (dd, J=8.2, 2.3 Hz, 1H), 3.81
(s, 3H), 2.95 (q, J=7.2 Hz, 2H), 1.19 (t, J=7.3 Hz, 3H); 13C NMR
(100 MHz, CDCl3) δ 200.5, 159.8, 138.3, 129.5, 120.5, 119.1, 112.3,
55.3, 31.8, 8.2.
Acknowledgements
1-(4-Methoxy-phenyl)-propan-1-one (3vh):[42] White solid. Yield:
1
°
146.0 mg, 89%, mp 28–29 C. H NMR (400 MHz, CDCl3) δ 7.91–7.79
The authors thank the National Natural Science Foundation of
China (21962004, 21562004), Jiangxi provincial department of
(m, 2H), 6.85 (dd, J=8.7, 1.9 Hz, 2H), 3.81–3.74 (m, 3H), 2.90–2.81
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financially supported by Gannan Medical University (QD201832,
QD201816, YJ202027) and the Jiangxi Education Hall Science and
Technology Foundation (GJJ180801).
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Conflict of Interest
The authors declare no conflict of interest.
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Keywords: Iridium
borrowing mechanism · Synthetic methods
· Homogeneous catalysis · Hydrogen
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Manuscript received: November 26, 2020
Revised manuscript received: January 27, 2021
Accepted manuscript online: February 5, 2021
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