Catalytic Deoxygenative Coupling of Aromatic Esters with Organophosphorus Compounds

Article abstract of DOI:10.1021/jacs.0c02839

We have developed a deoxygenative coupling of aromatic esters with diarylphosphine oxides/dialkyl phosphonates under palladium catalysis. In this reaction, aromatic esters can work as novel benzylation reagents to give the corresponding benzylic phosphorus compounds. The key of this reaction is the use of phenyl esters, an electron-rich diphosphine as a ligand, and sodium formate as a hydrogen source. Arylcarboxylic acids were also applicable in this reaction using (Boc)2O as an additive. Palladium/dcype worked to activate the acyl C-O bond of the ester and to support the reduction with sodium formate.

Full text of DOI:10.1021/jacs.0c02839

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Communication
Catalytic Deoxygenative Coupling of Aromatic
Esters with Organophosphorus Compounds
Miki B. Kurosawa, Ryota Isshiki, Kei Muto, and Junichiro Yamaguchi
J. Am. Chem. Soc., Just Accepted Manuscript • DOI: 10.1021/jacs.0c02839 • Publication Date (Web): 11 Apr 2020
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Catalytic Deoxygenative Coupling of Aromatic Esters with Organo-
phosphorus Compounds
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Miki B. Kurosawa, Ryota Isshiki, Kei Muto, and Junichiro Yamaguchi*
Department of Applied Chemistry, Waseda University, 3-4-1, Ohkubo, Shinjuku, Tokyo 169-8555, Japan
ABSTRACT: We have developed a deoxygenative coupling of aromatic esters with diarylphosphine oxides/dialkyl phosphonates under pal-
ladium catalysis. In this reaction, aromatic esters can work as novel benzylation reagents to give the corresponding benzylic phosphorus com-
pounds. The key of this reaction is the use of phenyl esters, an electron-rich diphosphine as a ligand, and sodium formate as a hydrogen source.
Arylcarboxylic acids were also applicable in this reaction using (Boc)2O as an additive. Palladium/dcype worked to activate the acyl C–O
bond of the ester and to support the reduction with sodium formate.
Aromatic esters are frequently used as abundant, inexpensive
chemical feedstock in organic synthesis and can be derived into
various aromatic molecules. Therefore, a significant number of
substitution reactions from aromatic esters have been reported thus
far. Conventionally, these reactions involve an aromatic ester with a
nucleophile in a 1,2-addition reaction in which the nucleophile
attacks the carbonyl on the ester to produce the corresponding
aromatic ketones and alcohols (Figure 1A).
tive C–P bond formation between aromatic phenyl esters and or-
ganophosphorus compounds.[3e]
A. Conventional: 1,2-Addition of aromatic esters with nucleophiles
O
O
Nu
Nu
Nu
OR
aromatic esters
Nu
or
Ar
Ar
–OR
Ar
B. Emerging: Non-decarbonylative and decarbonylative transformations of aromatic
esters with nucleophiles
Recently, transition-metal-catalyzed non-decarbonylative and
decarbonylative transformations of aromatic esters with various
nucleophiles have received attention as an emerging method in
synthetic organic chemistry (Figure 1B). [1–4] In these reactions,
various nucleophiles can be introduced directly under the following
mechanism: Oxidative addition of the acyl carbon–oxygen (C–O)
bond of the phenyl arenoate to a transition metal (step A), followed
by attack of the nucleophile to the metal (step B), and subsequent
decarbonylation (step C) and/or reductive elimination (step D).
Based on this plausible mechanism, we hypothesized that the re-
duction of the non-decarbonylative product (formally the same as
the 1,2-adducts obtained conventionally) with an appropriate re-
ducing agent is faster than decarbonylation (step C), giving a deox-
ygenative product (step E). Conventionally, this chemical trans-
formation requires three steps; reduction of an ester, halogenation
of the resulting alcohol, and nucleophilic substitution of the ensu-
ing benzyl halide. However, under this hypothesis, aromatic esters
should behave like benzyl halides, and react with nucleophiles in a
single step. Additionally, it might be possible to use various nucleo-
philes that have been developed for non-decarbonylative and de-
carbonylative ester transformations. As our first step toward devel-
oping this new type of transformation, herein we report a deoxy-
genative carbon–phosphorus (C–P) bond formation reaction using
aromatic esters as benzylating agents under palladium catalysis
(Figure 1C). Such organophosphorus products could potentially
be useful as synthetic intermediates, bioactive molecules and lig-
ands for transition metal catalysis.[5]
O
O
M
Nu
Nu
OPh
M
Nu
M
Ar
Ar
–CO
step C
Ar
–OPh
step B
M
step A
OPh
step D
cat.
M
O
O
Nu
Nu
Nu
or
Ar
Ar
–OPh
(–CO)
Ar
non-decarbonylative
product
decarbonylative
product
M
: transition metal: mainly Ni or Pd
appropriate
reductant
step E
■ Esters: Novel and abundant
Nu
“benzylating” agents
■ Mild Conditions: No strong
reductant and halogenation
■ Step-economy: Single step
operation
Ar
deoxygenative
product
C. New transformation (This work): Deoxygenative coupling of aromatic esters
with a nucleophile (phosphorus compounds)
Pd
O
O
O
HCOONa
H
P
P
+
OPh
Ar
R
R
Ar
–OPh
–[O]
R
R
Figure 1. Chemical transformation of aromatic esters. (A) Conven-
tional approach. (B) Emerging methods. (C) Deoxygenative coupling
with phosphorus compounds
With
a
Ni(OAc)2/dcypt
[3,4-
Regarding the decarbonylative transformation of aromatic esters,
our group has recently developed a nickel-catalyzed decarbonyla-
bis(dicyclohexylphosphino)thiophene] catalyst, aromatic esters
can function as arylating agents to give the corresponding aromatic
phosphorus compounds. For example, phenyl thiophene-2-
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Page 2 of 7
carboxylate (1A) and diphenylphosphine oxide (2A) with 5 mol %
the ligand was changed from dcypt to various phosphine lig-
ands,the highest yield of 3A was obtained (89% yield) without any
decarbonylative product 4A (using dcype, Table 1, entries 8–16). It
should be noted that the reaction hardly proceeds without the Pd
metal or the ligand (Table 1, entries 17–19).
1
2
3
4
5
6
7
8
Ni(OAc)2/dcypt catalyst and NaF (1.5 equiv) as an additive in
tAmylOH at 170 °C only produced the undesired decarbonylative
product 4A in 64% yield (Table 1, entry 1). To realize the hypothe-
sized deoxygenative coupling, we set out to change the reaction
conditions. Using the same catalyst, 1.5 equiv of sodium formate
With optimal conditions in hand, the substrate scope of aromatic
esters 1 and organophosphorus compounds 2 was investigated
(Scheme 1). This reaction was applicable to various heteroaro-
matic esters, not only to phenyl 2-thienoate (1A) but also to 3-
thienoate (1B), 2-furanoate (1C), 2-picolinate (1E), isonicotinates
and nicotinates (1F and 1G), pyrazinoates (1H and 1I), isoquino-
linates (1J), and quinolinates (1K and 1L) to give the correspond-
ing deoxygenative products 3B–3L in moderate to good yields. In
terms of simple arenoates such as p-tolyl (1M), naphthyl (1N),
anthracenyl (1P), and biphenyl (1Q–1S) as the aryl group, the
deoxygenative coupling also worked well to afford the correspond-
ing products 3M–3S in moderate yields. Electron-withdrawing or
electron-donating substituents at the para position of the phenoate,
such as methoxy (1T), alkoxy (1U), trifluoromethoxy (1V), and
trifluoromethyl (1W) groups did not affect the yields of products
3T–3W. Next, we examined the functional group tolerance for this
reaction. Indeed, this reaction showed high functional group toler-
ance and proceeded with aromatic phenyl esters bearing thiome-
thyl (3X), cyano (3Y), dimethylamino (3Z), vinyl (3AA), acetyl
(3AB), and methyl carboxylate (3AC) groups. This deoxygenative
coupling proceeded even when different diarylphosphine oxides
were used instead of 2A, affording the corresponding coupling
products 3AD–3AF. Although disubstituted phosphites and phos-
phinate were less applicable substrates compared with phosphine
oxides, they reacted with 1A to give the corresponding coupling
products 3AG and 3AH. We also attempted this reaction with the
phenyl ester of probenecid, telmisartan, and febuxostat, which are
well-known pharmaceuticals, and succeeded in obtaining products
3Al–3AK in moderate yields. It should be noted that several sub-
strates required 2.0 equiv of sodium formate and higher tempera-
tures to increase the yields. Regarding to the limitation of this pro-
tocol at this stage, alkyl (Alk–CO2Ph) and alkenyl esters did not
deliver the corresponding products (see the Supporting Infor-
mation for details).
At this stage, it can be hypothesized following two routes; 1) di-
rect reduction of 1A and then coupling of the resulting etherific C–
OPh bond of 5F with 2A under palladium catalysis;[7] 2) reduction
to the aldehyde and addition with 2A, followed by a phospha-
Brook rearrangement[8,9] and transformation of the C–OP(O)Ph2
bond by the palladium catalyst (Figure 2A). To understand the
reaction mechanism, several control experiments were performed.
Firstly, phenyl ester 1A was changed to various other carbonyl
compounds 5A–5H, which includes possible reaction intermedi-
ates (Figure 2B). This reaction could not be accomplished with
methyl ester 5A and aldehyde 5B. When 4-trifluorophenyl ester 5C,
acid chloride 5D and thioester 5F were used, the desired product
3A was obtained, albeit in lower yields. These results indicate that
this reaction can only be achieved using “activated” aroyl com-
pounds. However, possible intermediates such as aldehyde 5B,
phenyl ether 5F, and benzylic phosphine oxide 5G did not affect
the reaction, which means ruling out our mechanistic hypotheses 1
and 2.
t
(HCOONa) as a hydrogen source (a reductant) in AmylOH at
150 °C for 12 h were used as the initial screening conditions (Table
1, entry 2). This successfully gave the desired deoxygenative prod-
uct 3A in 18% yield along with the decarbonylative product 4A in
9
t
60% yield. Changing the solvent from AmylOH to 1,4-dioxane as
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well as 1,2-dimethoxyethane (DME) increased the yield of desired
3A, particularly when DME was used as the solvent, giving 3A in
35% yield as a single product (Table 1, entries 3 and 4). However,
nickel catalysis could not improve the yield of 3A after extensive
investigations.[6] To our delight, when nickel was changed to palla-
dium salts such as Pd(OAc)2, Pd2(dba)3·CHCl3, and PdCl2, the
yield of 3A significantly improved to 63% yield as the best result
and no 4A was observed (Table 1, entries 5–7). Furthermore, when
Table 1. Screening of reaction conditions.a
5.0 mol % metal salt
10 mol % ligand
HCOONa
O
O
Ph
O
O
P
H
(1.5 equiv)
P
+
P
+
OPh
Ph
Ph
Ph
Ph
Ph
S
S
S
solvent
150 °C, 12 h
1A
(0.20 mmol)
2A
(1.5 equiv)
3A
deoxygenative
product
4A
decarbonylative
product
entry
1b
2
metal
ligand
solvent
tAmylOH
tAmylOH
dioxane
DME
3A/4A (%)
0/64
18/60
33/44
35/0
62/0
60/0
63/0
67/0
46/0
60/0
35/0
31/0
16/0
15/0
55/0
89/0
4/0
Ni(OAc)2
Ni(OAc)2
Ni(OAc)2
Ni(OAc)2
Pd(OAc)2
dcypt
dcypt
dcypt
dcypt
dcypt
dcypt
dcypt
dppe
dppbz
PnBu3
XPhos
BINAP
PPh3
bipy
3
4
5
DME
c
6
Pd2(dba)3
PdCl2
PdCl2
PdCl2
PdCl2
PdCl2
PdCl2
PdCl2
PdCl2
PdCl2
PdCl2
–
DME
7
DME
8
DME
9
DME
10
11
12
13
14
15
16
17
18
19
DME
DME
DME
DME
DME
IPr·HCl
dcype
–
DME
DME
DME
PdCl2
–
–
DME
1/0
dcype
DME
0/0
a Conditions; 1A (0.20 mmol), 2A (0.30 mmol), metal (5.0 mol %),
ligand (monodentatel; 10 mol %, bidentate; 20 mol %), HCOONa
b
(1.5 equiv), solvent (1.0 mL), 150 °C, 12 h. NMR yield, NaF (1.5
equiv) instead of HCOONa was used at 170 °C for 18 h.
On the other hand, acyl phosphine oxide 5H, which was a mois-
ture-sensitive compound, reacted to give 3A in 49% yield. This
result supports that 5H is a reaction intermediate. Next, we
cPd2(dba)3·CHCl3 (2.5 mol %) was used. dcype
Bis(dicyclohexylphosphino)ethane.
= 1,2-
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Scheme 1. Substrate scopea
1
2
3
4
5
6
7
8
9
5.0 mol % PdCl2
10 mol % dcype
HCOONa (1.5 equiv)
O
O
O
H
+
OPh
P
P
Ar
Ar
R
R
DME (0.20 M)
150 °C, 12 h
P
P
R
R
dcype
1 (0.20 mmol)
2 (1.5 equiv)
3
37 examples
heteroarenes
O
O
P
O
O
O
O
N
P
P
P
P
P
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
3F : 72%c
S
O
N
N
S
O
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
3A : 89%
3B : 76%
3C : 91%b
3D : 38%c,d
3E : 66%c
O
O
O
O
O
O
N
MeO
N
P
P
P
P
P
P
Ph
Ph
Ph
Ph
Ph
Ph
Ph
N
Ph
Ph
N
Ph
Ph
Ph
N
N
N
Me
N
Ph
3L : 51%
3G : 71%c
3H : 65%
3I : 46%
3J : 59%c
3K : 39%c
arenes
O
O
O
O
P
O
Ph
P
P
P
Ph
O
Ph
Ph
P
Ph
Ph
Ph
Ph
Ph
P
Ph
Me
MeO
Ph
Ph
R
3R (R = H): 31%d
3O : 52%
3P : 41%d
3M : 65%c
3N : 52%c
3Q : 52%c
3S (R = tBu): 71%c
arenes with functional groups
O
P
O
O
O
P
O
MeS
O
O
P
P
P
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
MeO
CF3O
CF3
3T : 57%c
3U : 49%c
3V : 52%c,d
3W : 64%c
3X : 58%c,d
O
P
O
O
P
O
P
O
Me2N
P
P
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
3AB : 60%b,c,d
Me
Ph
Me
MeO
NC
O
O
3Y : 51%c
3Z : 78%
3AA : 48%
3AC : 56%b,c
phosphorus compounds
pharmaceuticals
nPr
N
N
Me
O
Me
nPr
P
O
O
P
OnBu
O
N
N
O
Ph
P
P
OnBu
Ph
S
N
S
O
Ar
OEt
nPr
P
Me
Ar
S
Ph
S
S
Ph
Ph
Me
O
O
N
O
NC
P
Ph
Ph
3AI: 63%c
from probenecid
3AJ : 50%c
from telmisartan
3AK : 60%c
from febuxostat
3AD (Ar = p-tolyl): 58%
3AE (Ar = p-anisyl): 26%
3AF (Ar = 3,5-di-MeOC6H3): 53%
3AG : 30%d
3AH : 29%
a Conditions; 1 (0.20 mmol), 2 (0.30 mmol), PdCl2 (5.0 mol %), dcype (10 mol %), HCOONa (1.5 equiv), DCE (1.0 mL), 150 °C, 12 h. b 2A (3.0
equiv) was added. c HCOONa (2.0 equiv) was added. d The reaction was performed at 160 °C.
wondered whether acyl phosphine oxide 5H was produced by a
simple 1,2-addition reaction of aromatic phenyl ester 1 with di-
phenylphosphine oxide (2A) or not. Hence, we conducted a con-
trol experiment, in which 1A was mixed with 2A under optimal
conditions without a palladium catalyst (Figure 2C). As a result,
5H was not produced, and both starting materials were recovered.
With this result, we speculate that 5H is likely formed by a non-
decarbonylative coupling pathway involved by the palladium catal-
ysis (see Figure 1, step A and B, followed by step D).
reduced under Pd/HCOONa catalytic system. Finally, the reaction
was conducted using deuterated sodium formate (DCOONa)
and/or diphenylphosphine oxide d-2A (Figure 2E).[10] When only
DCOONa was used, a mixture of hydrogenated (3A) and deuter-
ated (d1-3A and d2-3A) forms at the benzylic proton of 3A was
obtained with a ratio of 44:44:12 (3A:d1-3A:d2-3A). Subsequently,
when only deuterated d-2A was used, the ratio of deuterated prod-
ucts was increased (22:39:39). Finally, both deuterated reagents
were combined to give a product mixture with a ratio of (14:29:57).
These experiments reveal that both sources of deuterium are in-
volved in the reduction of the carbonyl group, and that other
sources of hydrogen are seemingly present in the reaction system.
We also confirmed that possible reduction intermediates such as
5H, 5I and 5J can be transformed into 3A (Figure 2D). In all cases,
the desired product 3A were given, which means that 5H can be
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A. Proposed mechanisms
Hypothesis 1
Hypothesis 3
O
1
2
3
4
H
O
P
[Pd]
HCOONa
2A
[Pd]
O
O
P
2
O
O
R
O
[Pd]
R
R
OPh
OPh
P
OPh
Ph
Ar
[Pd]
Ar
[Pd]
Ph
S
Ar
OPh
R
S
S
–PhOH
oxidative
addition
reduction
substitution
1A
5F
3A
1
A
B
5
6
7
8
O
[Pd]
HCOONa
Hypothesis 2
O
R
O
–[Pd]
O
O
OH
[Pd]
HCOONa
2A
HCOONa
Ar
P
Ar
P
R
O
hydrogenation
reductive
R
R
OPh
H
P
elimination
Ph
3
5
Ph
S
reduction
addition
S
S
9
1A
5B
5I
[Pd]
HCOONa
hydrogenation
O
H
P
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
R
phospha-Brook
2A
R
OPOPh2
O
O
POR2
O
P
Ph
HO
Ar
R
[Pd]
P
O
P
Ar
P
O
phospha-Brook
rearrangement
Ph
Ph
R
R
Ph
S
substitution
S
R
3A
5G
7
6
B. Using other carbonyl compounds and possible intermediates
C. Control experiments
O
O
HCOONa (1.5 equiv)
O
H
5.0 mol % PdCl2
10 mol % dcype
HCOONa (1.5 equiv)
O
+
P
P
O
Ph
Ph
OPh
O
Ph
H
Ph
S
DME (0.2 M)
150 °C, 12 h
without catalyst
[0% yield]
R
P
+
P
S
Ph
Ph
DME (0.20 M)
150 °C, 12 h
Ph
Ph
S
2A
5H
1A
S
5A–5H
2A
3A
D. Reactions of possible reduction intermediate without 2A
O
O
O
5.0 mol % PdCl2
10 mol % dcype
HCOONa (1.5 equiv)
OPh
OMe
H
O
S
S
S
P
or
or
5H
5I
5J
Ph
Ph
5A
0% yield
5B
0% yield
ruling out hypothesis 2
1A
89% yield
S
DME
150 °C
3A
O
OH
OPOPh2
O
CF3
O
O
O
O
O
P
P
P
Cl
SPh
S
Ph
Ph
Ph
Ph
O
Ph
Ph
S
S
S
S
S
5H
44% yield
5I
5J
65% yield
5D
28% yield
5E
5C
74% yield
21% yield
40% yield
E. Deuterium labeling experiments
O
O
O
P
D
D
P
H
D
Ph
Ph
3A:d1-3A:d2-3A
OPh
O
O
O
Ph
P
with DCOONa: 44 : 44 : 12
with d-2a: 22 : 39 : 39
with DCOONa+d-2a: 14 : 29 : 57
P
Ph
S
S
S
3A
Ph
Ph
Ph
Ph
S
S
5F
0% yield
ruling out hypothesis 1
5G
0% yield
ruling out hypothesis 2
5H
d1-3A
d2-3A
49% yield
Figure 2. (A) Proposed mechanisms. (B) Deoxygenative coupling using other carbonyl compounds and possible intermediates. (C) Control experi-
ments. (D) Reactions of possible reduction intermediates without 2A. (E) Deuterium labeling experiments.
Based on the above experiments, a plausible mechanism is de-
picted in Figure 2A (Hypothesis 3). First, oxidative addition of the
acyl C–O bond of phenyl ester 1 onto palladium produces palladi-
um complex A. Then, ligand exchange from phenoxy (OPh) to
diaryl phosphine oxide 2 produces complex B and phenol, followed
by reductive elimination to give non-decarbonylative product 5.
Because the phosphine oxide bearing carbonyl group of 5 is elec-
tron-deficient, hydrogenation of 5 proceeds under palladium and
sodium formate to afford the organophosphorus compound 3. As a
minor process of the hydrogenation, 5 can react with another mol-
ecule of 2, thus forming 6, followed by phospha-Brook rearrange-
ment to give intermediate 7.[8,9] Then, hydrogenation of 7 furnish-
es the deoxygenative product 3.
Scheme 2. Deoxygenative coupling from arylcarboxylic acids.
5.0 mol % PdCl2
10 mol % dcype
HCOONa (1.5 equiv)
O
O
O
Boc2O (2.0 equiv)
H
P
+
P
Ph
Ph
OH
Ph
S
Ph
DME (0.2 M)
150 °C, 12 h
[68% yield]
S
3A
2A
8
O
O
O
above conditions
[78% yield]
Me2N
H
P
+
P
Me2N
Ph
Ph
OH
Ph
3Z
Ph
2A
9
In summary, we succeeded in developing a deoxygenative car-
bon–phosphorus bond formation reaction between aromatic esters
and organophosphorus compounds using a palladium catalyst. The
catalyst has two roles: activation of the acyl C–O bond of the aro-
matic ester and catalytic reduction in conjunction with HCOONa.
Expanding the range of substrates and nucleophiles for this new
type of transformation is currently underway in our laboratory.[12]
Finally, we wanted to achieve this deoxygenative coupling direct-
ly from arylcarboxylic acids (Scheme 2). To our optimized condi-
tions was added (Boc)2O: 2-thiophenecarboxylic acid (8) as well as
3-dimethylaminobenzoic acid (9) were reacted with 2A through in
situ acid anhydride formation, resulting in the corresponding deox-
ygenative products 3A and 3Z in good yields.[11]
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ylsilanes and Heteroarylsilanes. Angew. Chem., Int. Ed. 2016, 55, 11810–
ASSOCIATED CONTENT
11813. (b) Pu, X.; Hu, J.; Zhao, Y.; Shi, Z. Nickel-Catalyzed Decarbonyla-
tive Borylation and Silylation of Esters. ACS Catal. 2016, 6, 6692–6698.
(c) Yue, H.; Guo, L.; Liao, H.-H.; Cai, Y.; Zhu, C.; Rueping, M. Selective
Reductive Removal of Ester and Amide Groups from Arenes and Het-
eroarenes through Nickel-Catalyzed C–O and C–N Bond Activation.
Angew. Chem., Int. Ed. 2017, 56, 3972–3976. (d) Takise, R.; Isshiki, R.;
Muto, K.; Itami, K.; Yamaguchi, J. Decarbonylative Diaryl Ether Synthesis
by Pd and Ni Catalysis. J. Am. Chem. Soc. 2017, 139, 3340–3343. (e)
Isshiki, R.; Muto, K.; Yamaguchi, J. Decarbonylative C−P Bond Formation
Using Aromatic Esters and Organophosphorus Compounds. Org. Lett.
2018, 20, 1150–1153. (f) Lee, S.-C.; Liao, H.-H.; Chatupheeraphat, A.;
Rueping, M. Nickel-Catalyzed C–S Bond Formation via Decarbonylative
Thioetherification of Esters, Amides and Intramolecular Recombination
Fragment Coupling of Thioesters. Chem. Eur. J. 2018, 24, 3608–3612.
Related C–P bond formation using amides, see: (g) Liu, C.; Szostak, M.
Decarbonylative Phosphorylation of Amides by Palladium and Nickel
Catalysis: The Hirao Cross-Coupling of Amide Derivatives. Angew. Chem.,
Int. Ed. 2017, 56, 12718–12722.
(4) For selected examples of non-decarbonylative transformations of
aromatic esters using metal catalysis, see: (a) Tatamidani, H.; Kakiuchi, F.;
Chatani, N. A New Ketone Synthesis by Palladium-Catalyzed Cross-
Coupling Reactions of Esters with Organoboron Compounds. Org. Lett.
2004, 6, 3597–3599. (b) Hie, L.; Nathel, N. F. F.; Hong, X.; Yang, Y.-F.;
Houk, K. N.; Garg, N. K. Nickel-Catalyzed Activation of Acyl C–O Bonds
of Methyl Esters. Angew. Chem., Int. Ed. 2016, 55, 2810–2814. (c) Halima,
T. B.; Zhang, W.; Yalaoui, I.; Hong, X.; Yang, Y.-F.; Houk, K. N.; Newman,
S. G. Palladium-Catalyzed Suzuki–Miyaura Coupling of Aryl Esters. J. Am.
Chem. Soc. 2017, 139, 1311–1318. (d) Halima, T. B.; Vandavasi, J. K.;
Shkoor, M.; Newman, S. G. A Cross-Coupling Approach to Amide Bond
Formation from Esters. ACS Catal. 2017, 7, 2176–2180. (e) Shi, S.; Lei, P.;
1
2
3
4
5
6
7
8
Supporting Information
The Supporting Information is available free of charge on the ACS
Publications website.
Experimental procedures and spectroscopic data for compounds in-
cluding 1H-, 13C, 31P NMR spectra (PDF)
AUTHOR INFORMATION
Corresponding Author
*junyamaguchi@waseda.jp
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ORCID
Kei Muto: 0000-0001-8301-4384
Junichiro Yamaguchi: 0000-0002-3896-5882
Notes
No competing financial interests have been declared.
ACKNOWLEDGMENT
This work was supported by JSPS KAKENHI Grant Number
JP19H02726 (to J.Y.), JP18H04661 (Hybrid Catalysis), and
JP19K15573 (to K.M.). We thank Prof. Masahiro Terada (Tohoku
University) for fruitful discussion about the reaction mechanism. The
Materials Characterization Central Laboratory in Waseda University is
acknowledged for the support of HRMS measurement.
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ChemRxiv: Kurosawa, M. B.; Isshiki, R.; Muto, K.; Yamaguchi, J. Catalytic
Deoxygenative Coupling of Aromatic Esters with Organophosphorus
Compounds.
ChemRxiv
Preprint
2020.
DOI:
10.26434/chemrxiv.11973585.
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Pd
O
O
O
HCOONa
H
P
P
+
OPh
Ar
R
R
Ar
–OPh
–[O]
R
R
5
37 examples
deoxygenative coupling
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■ Esters: Novel and abundant “benzylating” agents
■ Mild Conditions: No strong reductant and halogenation
■ Step-economy: Single step operation from starting materials
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