Silver-Catalyzed para -Selective C-H Amination of 1-Naphthylamides with Azodicarboxylates at Room Temperature

Article abstract of DOI:10.1055/s-0037-1610705

A simple and efficient protocol for para -selective C-H amination of 1-naphthylamide derivatives under silver catalysis is described. This reaction system could proceed without the help of directing group and a broad range of substrates were proved to be well tolerated. In addition, control experiments suggested that this reaction might not proceed via a single-electron-transfer process.

Full text of DOI:10.1055/s-0037-1610705

SYNTHESIS
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© Georg Thieme Verlag Stuttgart · New York
2019, 51, A–H
special topic
A
en
Q.-Z. Li et al.
Special Topic
Synthesis
Silver-Catalyzed para-Selective C–H Amination of 1-Naphthyl-
amides with Azodicarboxylates at Room Temperature
Quan-Zhe Lia
O
O
Xun-Hui Wanga
Si-Hua Houa
Yan-Yan Mab
Deng-Gao Zhaob
Shu-Yu Zhanga
He-Yuan Bai*a
Tong-Mei Ding*a
R1
HN
R1
HN
N
R3
AgF (10 mol%)
N
N
R2
R2
+
R3
1,4-dioxane, rt, air
R3
H
0
0
0
0-0
0
0
2-1
8
1
1-
4
1
5
9
N
R3
H
21 examples
up to 98% yield
a Shanghai Key Laboratory for Molecular Engineering of Chiral
Drugs & School of Chemistry and Chemical Engineering,
Shanghai Jiao Tong University, Shanghai 200240, P. R. China
dtm@sjtu.edu.cn
baiheyuan90@sjtu.edu.cn
b School of Biotechnology and Health Sciences, Wuyi University,
Jiangmen 529020, P. R. China
Published as part of the Special Topic Amination Reactions in
Organic Synthesis
Received: 13.02.2019
Accepted after revision: 19.03.2019
Published online: 11.04.2019
two types of catalysis (Cu/Ru photoredox catalysis or Cu/Ag
cocatalysis) for the remote C–H sulfonylation of 1-naphth-
ylamides at room temperature with PA as the directing
group.7 In 2018, Wu’s group discussed a silver-catalyzed PA
directed C4–H amination of 1-naphthylamine derivatives
with azodicarboxylates.8 These synthetic methods all need
a directing group and proceed via a single-electron-transfer
(SET) mechanism; however, the introduction and subse-
quent removal of protecting groups not only require addi-
tional operations but also significantly decrease functional
group compatibility. C4-substituted 1-naphthylamine
framework exists in many pharmaceutical agents such as
myeloid cell leukemia 1 (Mcl-1) inhibitor, chemokine recep-
tor 8 (CCR8) antagonist, and 5-hydroxytryptamine receptor
6 (5-HT6) antagonist.9 Therefore, it is meaningful and chal-
lenging to develop a straightforward and practical approach
for the direct C4–H amination of 1-naphthylamides without
a directing group.
Azodicarboxylates, which contain a central azo func-
tional group, are very popular substrates for C–N bond-
forming reactions and many derivatives thereof are also
commercially available.10 Over the past three years, our lab-
oratory has introduced several novel C–H aminations11 us-
ing azodicarboxylates as the amino source with different
directing groups (Scheme 1b). To the best of our knowledge,
there is no report on the C–H amination at the C4 position
of 1-naphthylamide without the help of a directing group.
Herein, we have developed a straightforward and practical
approach for the direct C–H amination at the definite C4
position of 1-naphthylamides (Scheme 1c). The reactions
proceed under simple and mild conditions without any ad-
ditional directing group at room temperature and air atmo-
DOI: 10.1055/s-0037-1610705; Art ID: ss-2019-c0093-st
Abstract A simple and efficient protocol for para-selective C–H amina-
tion of 1-naphthylamide derivatives under silver catalysis is described.
This reaction system could proceed without the help of directing group
and a broad range of substrates were proved to be well tolerated. In ad-
dition, control experiments suggested that this reaction might not pro-
ceed via a single-electron-transfer process.
Key words transition metal, azodicarboxylates, regioselective, amina-
tion
Transitional-metal-catalyzed C–H functionalization has
emerged as a reliable and robust tool for C–N formation in
organic synthesis. Naphthalenes are important structural
1
unit in pharmaceuticals, agrochemicals, and functional ma-
terials 2 and considerable efforts have been directed toward
the simple and efficient construction of substituted naph-
thalenes.3 Significant advances have been made in the di-
rect functionalization of 1-naphthylamines, especially for
the highly selective C2–H and C8–H functionalization of 1-
naphthylamine via the directing group (DG)-assisted C–H
bond activation strategy.4,5 However, the remote aromatic
C–H functionalization remains extremely difficult, due to
the limitation of directing group.
In recent years, some researchers focused on the devel-
opment of the para C–H functionalization of naphthyl-
amines (Scheme 1a). In 2017, Lu’s group developed an effi-
cient protocol catalyzed by copper for C–H functionaliza-
tion of 1-naphthylamine derivatives at C4–H site directed
by picolinic acid (PA).6 Then Wu and co-workers reported
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2019, 51, A–H

B
Q.-Z. Li et al.
Special Topic
Synthesis
portant effect in this model reaction. From all the above re-
sults, the condition showed in entry 7 was chosen as the
optimized one.
a) PA-mediated intermolecular remote functionalization of naphthalenes
SO2Ph
SO2Ph
O
O
N
N
H
H
Table 1 Optimization of the Reaction Conditionsa
N
N
Lu (2017)
Cu catalysis
Wu (2017)
Ru/Cu or Cu/Ag catalysis
O
CO2R
O
HN
HN
N
Ph
N
HN
Ph
O
CO2R
Cat. (10 mol%)
rt, air, 24 h
EtO2C
+
N
N
N
H
CO2Et
N
EtO2C
Wu (2018)
Ag catalysis
N
CO2Et
H
H
b) Our recent work
1a
2a
3aa
O
R2
R2
O
Entry
Catalyst
Solvent
Yield (%)b
R1
R3HN
α
β
N
R3HN
N
R3
N
N
N
H
1
2
Cu(OAc)2
Co(OAc)2
Ni(acac)2
AgOAc
Ag2CO3
AgTFA
AgF
1,4-dioxane
1,4-dioxane
1,4-dioxane
1,4-dioxane
1,4-dioxane
1,4-dioxane
1,4-dioxane
1,4-dioxane
DCM
trace
trace
trace
39
R3
R1
N
R2
(2017, 2018)
(2018)
R3
N
3
O
R2
O
NHR3
4
R1
R3
γ
N
N
5
13
R
N
H
N
N
NHR3
6
<5
R2
(2018)
(2018)
7
98
c) This work
O
8
AgOTf
AgF
<5
O
HN
N
R1
9
72
HN
R1
R3
AgF (10 mol%)
10
11
12
13
14
15c
16d
AgF
DCE
80
N
N
R2
+
R2
R3
AgF
toluene
22
1,4-dioxane, rt, air
R3
AgF
MeOH
10
H
N
R3
H
AgF
acetone
75
Scheme 1 a) PA-mediated intermolecular remote functionalization of
naphthalenes b) Our previous work c) This work
AgF
MeCN
69
AgF
1,4-dioxane
1,4-dioxane
76
AgF
90
sphere, providing desired products in good to excellent
yields.
a Reaction conditions: 1a (0.1 mmol), 2a (0.15 mmol), and catalyst (10
mol%) in solvent (1 mL) stirred under air for 24 h.
b Isolated yields.
Initially, we commenced our investigation by the reac-
tion of N-(naphthalen-1-yl)benzamide (1a) and diethyl
azodicarboxylate (DEAD, 2a) as the model reaction. As
shown in Table 1, various metals such as Cu, Co, Ni were
employed for this remote C4-amination of 1-naphthylam-
ide. But no product could be acquired, indicating the chosen
catalysts had no catalytic activity (Table 1, entries 1–3).
When using AgOAc as the catalyst, the desired product
could be produced in 39% yield. Then we chose different Ag
salts as the catalyst, and AgF was proved to be the optimal
catalyst, affording 3aa in 98% yield (entries 4–8). Subse-
quently, various solvents were screened and the highest
yield was achieved in 1,4-dioxane (entries 9–14). Finally,
the effect of the catalyst amount was explored. The results
showed that when the catalyst amount was decreased to 5%
or increased to 15%, the yield of desired product 3aa de-
creased (entries 15, 16)). So, the optimal catalyst amount
was determined at 10%, indicating that AgF played an im-
c AgF: 5 mol%.
d AgF: 15 mol%.
Under the optimized conditions, we then explored the
applicability of the present amination protocol for N-
(naphthalen-1-yl)amide derivatives (Scheme 2). 1-Naphth-
ylamides with various substituted groups at R1 position
were first examined. All tested linear and cyclic carboxam-
ides were well tolerated and gave 3ba–ia in high isolated
yields (68–98%). Then various substituents at different po-
sitions of naphthalene were examined, which generated
the corresponding products 3ja–qa efficiently. Different
substituted groups like MeO, Me, Br, Et, Ph could provide
the corresponding amination products in excellent yields
(83–96%), indicating that the electronic effect has no evi-
dent influence. But for the substrate containing a cyclopro-
pyl substituent, the product 3na was obtained in relatively
lower yield of 50%. The results could be attributed to the
steric effect.
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2019, 51, A–H

C
Q.-Z. Li et al.
Special Topic
Synthesis
O
O
R1
CO2Et
HN
R1
HN
H
N
N
AgF (10 mol%)
+
EtO2C
R2
R2
1,4-dioxane
rt, air, 24 h
EtO2C
N
N
CO2Et
H
1
2a
3
O
O
O
O
O
S
NPhth
Ph
HN
HN
N
HN
N
HN
N
O
N
HN
CO2Et
CO2Et
HN
CO2Et
CO2Et
HN
CO2Et
HN
CO2Et
CO2Et
CO2Et
3ca: 98%
3ea: 92%
3ba: 77%
3da: 68%
O
O
O
O
Bn
O
HN
HN
O
HN
HN
O
N
N
N
HN
CO2Et
CO2Et
N
HN
CO2Et
CO2Et
HN
CO2Et
HN
CO2Et
CO2Et
3ha: 84%
CO2Et
3ga: 90%
3fa: 74%
3ia: 83%
O
O
O
O
HN
Ph
HN
Ph
HN
Ph
HN
Ph
CH3
Br
HN
N
N
N
N
CO2Et
HN
CO2Et
CO2Et
HN
CO2Et
HN
CO2Et
CO2Et
CO2Et
CO2Et
3ma: 87%
3ja: 83%
3la: 86%
3ka: 84%
O
O
O
O
HN
Ph
HN
Ph
HN
N
Ph
HN
Ph
O
O
N
Ph
HN
N
EtO2C
EtO2C
N
HN
CO2Et
3na: 51%
CO2Et
CO2Et
N
CO2Et
N
CO2Et
H
H
CO2Et
3oa: 92%
3qa: 96%
3pa: 95%
Scheme 2 Substrate scope of 1-naphthylamides. Reagents and conditions: 1 (0.1 mmol), 2 (0.15 mmol), AgF (10 mol%), and 1,4-dioxane (1 mL) at rt for
24 h. Isolated yields are shown. The reaction was conducted at 80 °C for the formation of compounds 3da and 3ha.
Under the optimized conditions, the scope of azodicar-
boxylates was also examined (Scheme 3). The ethyl-substi-
tuted, isopropyl-substituted, and benzyl-substituted azodi-
carboxylates afforded the corresponding products 3aa, 3ac,
and 3ad in excellent yields. However, the tert-butyl-substi-
tuted azodicarboxylate proceeded worse and led to the
product 3ab in only 55% yield, which could be attributed to
the steric hindrance of tert-butyl group. Unfortunately, azo
derivatives 2e and 2f was not suitable for this reaction, in-
dicating the importance of carboxyl group in azodicarbox-
ylates.
A
gram-scale reaction of N-(naphthalen-1-yl)ben-
zamide (1a) was conducted to demonstrate the synthetic
application of this protocol, and the C4–H anination prod-
uct was obtained in 93% yield under the same reaction con-
ditions (Scheme 4), indicating the successful scale-up of
this process.
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2019, 51, A–H

D
Q.-Z. Li et al.
Special Topic
Synthesis
O
a) Substrate patterns for mechanistic study
O
O
HN
HN
R3
AgF (10 mol%)
N
Ph
EtO2C
+
AgF (10 mol%)
N
N
No Reaction
R3
N
N
+
1,4-dioxane
rt, air, 24 h
1,4-dioxane
rt, air, 24h
CO2Et
R3
N
H
N
R3
H
1
2
3
O
b) The radical-trapping experiment
O
HN
Ph
O
O
O
AgF (10 mol%)
TEMPO (1.0 equiv)
HN
Ph
EtO2C
HN
N
HN
HN
N
N
+
1,4-dioxane
rt, air, 24h
CO2Et
N
CO2Et
EtO2C
N
H
H
EtO2C
iPrO2C
N
tBuO2C
N
N
CO2Et
N
CO2iPr
N
CO2tBu
3aa (86% yield)
1a (0.1 mmol)
2a (0.15 mmol)
H
H
H
3aa: 98%
3ab: 55%
3ac: 98%
Scheme 5 Control experiments
O
O
O
HN
HN
HN
with DEAD to give rise to intermediate II. Finally, the rearo-
matization beomes favorable and the N–Ag bond is severed
by HF to regenerate AgF for the next cycle, and the desired
amination product 3aa is obtained.
N
Ph
N
BnO2C
N
NC
N
N
Ph
N
CO2Bn
H
CN
3ae: 0%
H
H
3af: 0%
3ad:97%
O
Scheme 3 Substrate scope of azodicarboxylates. Reagents and condi-
tions: 1 (0.1 mmol), 2 (0.15 mmol), AgF (10 mol%), and 1,4-dioxane (1
mL) at rt for 24 h. Isolated yields are shown.
HN
Ph
O
HN
Ph
N
CO2Et
O
EtO2C
N
O
AgF
H
3aa
HN
Ph
HN
Ph
1a
EtO2C
AgF (10 mol%)
N
N
+
HF
CO2Et
1,4-dioxane
rt, air, 24h
O
N
CO2Et
H
Ag
EtO2C
N
O
H
N
Ph
HF
Ag
N
Ph
1a (1 g)
2a (1.5 equiv)
3aa (93% yield)
Scheme 4 Synthetic application
CO2Et
CO2Et
N
II
I
HN
O
In order to gain insight into the mechanism for this re-
action, the substrate with the hydrogen atom substituted
by methyl at the amide nitrogen was used to react with
DEAD (Scheme 5a). However, the desired product could not
be obtained, showing that the hydrogen atom was indis-
pensable and played a critical role in this process. Then, a
radical-trapping experiment was also performed by the ad-
dition of 1.0 equivalent of TEMPO as radical scavenger
(Scheme 5b), and this reaction did not evidently inhibit the
formation of desired product 3aa, indicating our protocol
may not involve a SET mechanism.
Although the details of this amination reaction mecha-
nism need to be elucidated, a plausible proposal could be
put forward as in Scheme 6. First, the amide 1a reacts with
AgF to give the intermediate I and releases HF. Then inter-
mediate I progresses electron delocalization and proceeds
Ag
N
Ph
DEAD
H
N
EtO2C
N
CO2Et
Scheme 6 Proposed reaction mechanism
In conclusion, we have developed an efficient silver-cat-
alyzed direct amination of 1-naphthylamides with an excel-
lent degree of regioselectivity at C4-position based on the
direct C–H bond functionalization. This protocol is opera-
tionally simple, scalable, displays a broad substrate scope,
and uses commercially available azodicarboxylates as the
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2019, 51, A–H

E
Q.-Z. Li et al.
Special Topic
Synthesis
aminating agents. Notably, the amination reaction needs no
directing group compared with the former reported meth-
ods. The control experiments suggested that this amination
of 1-naphthylamide may not involve a SET mechanism. Fur-
ther investigation to extend the application of this method
is still in progress.
HRMS (ESI): m/z calcd for C21H21N3O5S [M + H]+: 428.1275; found:
428.1272.
Diethyl 1-{4-[(1R,4S)-4,7,7-Trimethyl-3-oxo-2-oxabicyc-
lo[2.2.1]heptane-1-carboxamido]naphthalen-1-yl}hydrazine-1,2-
dicarboxylate (3da)
Light yellow oil; yield: 33.6 mg (68%).
1H NMR (400 MHz, DMSO-d6):  = 10.33–9.92 (m, 2 H), 8.16 (br, 1 H),
7.93–7.88 (m, 1 H), 7.67–7.61 (m, 3 H), 7.54–7.50 (m, 1 H), 4.22–4.08
(m, 4 H), 2.59–2.53 (m, 1 H), 2.09–2.01 (m, 2 H), 1.69–1.63 (m, 1 H),
1.31–1.01 (m, 15 H).
13C NMR (101 MHz, DMSO-d6):  = 178.5, 166.8, 156.8, 155.7, 137.2,
133.4, 130.7, 130.3, 127.1, 126.8, 125.6, 124.8, 123.9, 92.7, 62.6, 61.7,
61.5, 55.1, 54.1, 30.6, 28.9, 17.1, 17.0, 14.9, 10.1.
1H NMR (400 MHz) and 13C NMR (100 MHz) spectra were recorded on
a Varian MERCURY plus-400 spectrometer with TMS as an internal
standard. HRMS was performed at the Analysis Center of Shanghai
Jiao Tong University. All commercially available substrates were used
as received. Amide substrates were prepared according to literature12
(see also: Supporting Information).
HRMS (ESI): m/z calcd for C26H31N3O7 [M + H]+: 498.2235; found:
498.2232.
Ag-Catalyzed Amidation Reactions; General Procedure
A mixture of amide 1 (0.1 mmol, 1 equiv), AgF (0.01 mmol, 0.1 equiv),
and azodicarboxylate 2 (0.15 mmol, 1.5 equiv) in 1,4-dioxane (1 mL)
in a 10 mL glass vial (sealed with a PTFE cap) was stirred at rt under
air for 24 h. The reaction mixture was concentrated in vacuo. The re-
sulting residue was purified by flash chromatography on silica gel to
give the desired product 3.
Diethyl (S)-1-{4-[2-(1,3-Dioxoisoindolin-2-yl)-3-phenylpropana-
mido]naphthalen-1-yl}hydrazine-1,2-dicarboxylate (3ea)
Light yellow oil; yield: 54.4 mg (92%).
1H NMR (400 MHz, DMSO-d6):  = 10.33–9.93 (m, 2 H), 8.15–8.04 (m,
2 H), 7.89–7.81 (m, 4 H), 7.68–7.61 (m, 3 H), 7.52–7.50 (m, 1 H), 7.25–
7.11 (m, 5 H), 5.42 (dd, J = 11.6, 4.7 Hz, 1 H), 4.20–4.05 (m, 4 H), 3.73
(dd, J = 14.0, 4.8 Hz, 1 H), 3.48 (t, J = 12.8 Hz, 1 H), 1.28–0.96 (m, 6 H).
13C NMR (101 MHz, DMSO-d6):  = 168.3, 168.0, 156.8, 155.7, 138.0,
137.0, 136.9, 135.0, 134.1, 131.9, 130.7, 130.2, 129.4, 128.8, 127.1,
127.0, 126.7, 125.6, 124.3, 123.9, 123.6, 62.6, 61.7, 61.5, 55.0, 38.7,
34.7, 14.9.
Diethyl 1-(4-Benzamidonaphthalen-1-yl)hydrazine-1,2-dicarbox-
ylate (3aa)
White solid; yield: 41.1 mg (98%).
1H NMR (400 MHz, CDCl3):  = 8.39 (s, 1 H), 8.08 (s, 1 H), 8.02–7.99
(m, 3 H), 7.97–7.93 (m, 1 H), 7.70 (br, 1 H), 7.64–7.53 (m, 5 H), 7.40
(br, 1 H), 4.23–4.21 (m, 4 H), 1.29–1.11 (m, 6 H).
13C NMR (101 MHz, CDCl3):  = 167.4, 156.7, 156.3, 136.1, 134.2,
133.3, 133.2, 132.0, 130.6, 129.0, 128.6, 128.5, 127.5, 127.4, 126.8,
126.4, 125.4, 123.4, 122.3, 63.0, 61.9, 14.3.
HRMS (ESI): m/z calcd for C33H30N4O7 [M + H]+: 595.2187; found:
595.2187.
Diethyl 1-(4-{[(Benzyloxy)carbonyl]amino}naphthalen-1-yl)hy-
drazine-1,2-dicarboxylate (3fa)
HRMS (ESI): m/z calcd for C23H23N3O5 [M + H]+: 422.1710; found:
422.1711.
White solid; yield: 33.4 mg (74%).
1H NMR (500 MHz, DMSO-d6):  = 10.31–9.85 (m, 2 H), 8.14–8.12 (m,
2 H), 7.71–7.57 (m, 4 H), 7.49 (d, J = 7.5 Hz, 2 H), 7.43 (t, J = 7.5 Hz, 2
H), 7.39–7.35 (m, 1 H), 5.23 (s, 2 H), 4.23–4.03 (m, 4 H), 1.29–0.98 (m,
6 H).
Diethyl 1-[4-(Cyclopropanecarboxamido)naphthalen-1-yl]hydra-
zine-1,2-dicarboxylate (3ba)
Light yellow oil; yield: 29.7 mg (77%).
13C NMR (126 MHz, DMSO-d6):  = 156.8, 155.7, 155.2, 137.2, 135.6,
134.4, 130.7, 128.9, 128.8, 128.53, 128.51, 127.1, 126.6, 125.7, 123.9,
123.5, 121.2, 66.5, 62.5, 61.7, 61.4, 14.92, 14.87, 14.8.
1H NMR (400 MHz, DMSO-d6):  = 10.28–9.88 (m, 2 H), 8.18–8.14 (m,
2 H), 7.74–7.72 (m, 1 H), 7.74–7.59 (m, 3 H), 4.20–4.04 (m, 4 H), 2.10
(pent, J = 6.3 Hz, 1 H), 1.32–0.84 (m, 10 H).
HRMS (ESI): m/z calcd for C24H25N3O6 [M + H]+: 452.1816; found:
452.1814.
13C NMR (126 MHz, CDCl3):  = 177.8, 161.6, 160.5, 140.6, 140.3,
139.1, 135.4, 135.3, 133.3, 131.8, 131.3, 130.4, 128.7, 128.2, 128.1,
126.4, 67.3, 66.4, 66.2, 19.7, 19.6, 19.4, 12.6.
HRMS (ESI): m/z calcd for C20H23N3O5 [M + H]+: 386.1710; found:
386.1715.
Diethyl 1-(4-Acetamidonaphthalen-1-yl)hydrazine-1,2-dicarbox-
ylate (3ga)
Brown oil; yield: 32.2 mg (90%).
1H NMR (400 MHz, DMSO-d6):  = 10.26–9.86 (m, 2 H), 8.14–8.11 (m,
2 H), 7.72–7.71 (br, 1 H), 7.63–7.58 (m, 3 H), 4.18–4.03 (m, 4 H), 2.22
(s, 3 H), 1.32–1.01 (m, 6 H).
Diethyl 1-[4-(Thiophene-2-carboxamido)naphthalen-1-yl]hydra-
zine-1,2-dicarboxylate (3ca)
White flocs; yield: 41.7 mg (98%).
13C NMR (101 MHz, CDCl3):  = 174.3, 161.5, 160.5, 140.5, 139.2,
135.4, 133.5, 131.7, 131.2, 130.4, 128.7, 128.3, 126.6, 67.3, 66.4, 66.2,
28.7, 19.7, 19.6.
HRMS (ESI): m/z calcd for C18H21N3O5 [M + H]+: 360.1554; found:
360.1555.
1H NMR (400 MHz, DMSO-d6):  = 10.56 (s, 1 H), 10.34–9.94 (m, 1 H),
8.18 (d, J = 3.8 Hz, 2 H), 8.05–8.03 (m, 1 H), 7.91 (d, J = 5.0 Hz, 1 H),
7.70–7.60 (m, 4 H), 7.29 (dd, J = 5.0, 3.8 Hz, 1 H), 4.23–4.04 (m, 4 H),
1.29–0.99 (m, 6 H).
13C NMR (101 MHz, DMSO-d6):  = 161.3, 156.8, 155.7, 140.0, 137.2,
137.0, 133.9, 132.4, 130.7, 130.3, 129.9, 128.7, 127.1, 126.8, 125.6,
124.3, 124.1, 62.6, 61.7, 61.5, 14.9.
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2019, 51, A–H

F
Q.-Z. Li et al.
Special Topic
Synthesis
Diethyl 1-[4-(6-Methoxy-6-oxohexanamido)naphthalen-1-yl]hy-
drazine-1,2-dicarboxylate (3ha)
1H NMR (400 MHz, DMSO-d6):  = 10.54–10.52 (m, 1 H), 10.14–10.03
(m, 1 H), 8.13 (d, J = 7.4 Hz, 2 H), 7.96 (d, J = 8.1 Hz, 2 H), 7.67–7.57 (m,
4 H), 7.48–7.40 (m, 2 H), 4.26–4.07 (m, 4 H), 2.78–2.76 (m, 3 H), 1.33–
1.03 (m, 6 H).
13C NMR (101 MHz, DMSO-d6):  = 166.7, 157.0, 156.9, 156.2, 155.5,
138.2, 137.7, 135.4, 134.8, 133.7, 132.3, 131.89, 131.86, 131.0, 130.7,
130.5, 129.05, 128.97, 128.3, 127.4, 126.2, 124.8, 123.0, 62.6, 61.7,
61.6, 23.0, 22.7, 15.1, 15.00, 15.4.96.
Colorless oil; yield: 38.7 mg (84%).
1H NMR (400 MHz, DMSO-d6):  = 10.28–9.87 (m, 2 H), 8.11–8.08 (m,
2 H), 7.71–7.57 (m, 4 H), 4.20–4.02 (m, 4 H), 3.61 (s, 3 H), 2.54–2.50
(m, 2 H), 2.41 (t, J = 6.8 Hz, 2 H), 1.72–1.63 (m, 4 H), 1.32–0.98 (m, 6
H).
13C NMR (101 MHz, DMSO-d6):  = 173.8, 172.3, 156.7, 155.7, 135.7,
134.3, 130.7, 128.8, 127.0, 126.5, 125.7, 124.0, 123.5, 121.9, 62.5, 61.7,
61.4, 51.7, 36.0, 33.5, 25.2, 24.6, 14.90, 14.85.
HRMS (ESI): m/z calcd for C24H25N3O5 [M + H]+: 436.1867; found:
436.1866.
HRMS (ESI): m/z calcd for C23H29N3O7 [M + H]+: 460.2078; found:
460.2077.
Diethyl 1-(4-Benzamido-8-ethylnaphthalen-1-yl)hydrazine-1,2-
dicarboxylate (3ma)
White powder; yield: 39.1 mg (87%).
Diethyl 1-[4-(3-Methylbutanamido)naphthalen-1-yl]hydrazine-
1,2-dicarboxylate (3ia)
1H NMR (400 MHz, DMSO-d6):  = 10.51 (d, J = 7.9 Hz, 1 H), 10.11–
10.00 (m, 1 H), 8.13 (d, J = 7.5 Hz, 2 H), 8.04–7.89 (m, 2 H), 7.67–7.57
(m, 4 H), 7.54–7.48 (m, 2 H), 4.25–4.10 (m, 4 H), 3.33–3.23 (m, 1 H),
3.21–3.10 (m, 1 H), 1.30–1.04 (m, 9 H).
13C NMR (101 MHz, DMSO-d6):  = 166.7, 157.0, 156.9, 156.1, 155.6,
139.7, 137.8, 137.1, 135.5, 134.8, 132.2, 132.0, 130.0, 129.7, 129.0,
128.3, 127.6, 126.2, 124.5, 122.7, 62.6, 62.5, 61.6, 26.7, 15.15, 15.08,
14.94, 14.90.
White solid; yield: 33.4 mg (83%).
1H NMR (400 MHz, DMSO-d6):  = 10.30–9.89 (m, 2 H), 8.13–8.08 (m,
2 H), 7.72–7.59 (m, 4 H), 4.22–4.05 (m, 4 H), 2.39 (d, J = 7.2 Hz, 2 H),
2.22–2.12 (m, 1 H), 1.38–0.91 (m, 12 H).
13C NMR (101 MHz, DMSO-d6):  = 171.9, 156.8, 155.7, 135.7, 134.3,
130.7, 128.9, 127.0, 126.5, 125.7, 124.0, 123.5, 122.1, 62.5, 61.7, 61.4,
45.6, 26.3, 22.8, 14.91, 14.86.
HRMS (ESI): m/z calcd for C25H27N3O5 [M + H]+: 450.2023; found:
450.2024.
HRMS (ESI): m/z calcd for C21H27N3O5 [M + H]+: 402.2023; found:
402.2028.
Diethyl 1-(4-Benzamido-8-cyclopropylnaphthalen-1-yl)hydra-
zine-1,2-dicarboxylate (3na)
Diethyl 1-(4-Benzamido-3-methylnaphthalen-1-yl)hydrazine-1,2-
dicarboxylate (3ja)
White solid; yield: 23.6 mg (51%).
White flocs; yield: 36 mg (83%).
1H NMR (400 MHz, DMSO-d6):  = 10.49 (d, J = 9.4 Hz, 1 H), 9.93–9.84
(m, 1 H), 8.11–8.08 (m, 2 H), 7.98–7.91 (m, 2 H), 7.67–7.56 (m, 4 H),
7.47–7.39 (m, 2 H), 4.25–3.98 (m, 4 H), 2.75–2.74 (br, 1 H), 1.28–1.16
(m, 4 H), 1.09–1.01 (m, 3 H), 0.90–0.82 (m, 2 H), 0.43–0.29 (m, 1 H).
13C NMR (101 MHz, DMSO-d6):  = 166.7, 157.3, 155.9, 155.8, 138.3,
138.1, 137.9, 137.1, 135.4, 134.8, 134.7, 132.2, 131.9, 131.8, 131.5,
131.2, 129.0, 128.9, 128.4, 128.29, 128.26, 127.4, 127.2, 126.1, 126.0,
124.6, 123.0, 62.5, 62.2, 61.7, 61.6, 16.2, 16.0, 15.01, 14.99, 14.95,
14.85, 9.4, 5.7.
1H NMR (400 MHz, DMSO-d6):  = 10.34–9.96 (m, 2 H), 8.15–8.07 (m,
3 H), 7.96–7.92 (m, 1 H), 7.68–7.56 (m, 6 H), 4.22–4.10 (m, 4 H), 2.39
(d, J = 4.8 Hz, 3 H), 1.30–1.03 (m, 6 H).
13C NMR (101 MHz, DMSO-d6):  = 166.3, 156.8, 155.7, 137.5, 134.6,
133.5, 132.4, 132.3, 132.2, 131.9, 129.3, 129.0, 128.2, 127.1, 126.2,
123.9, 62.6, 61.7, 61.5, 18.7, 14.9.
HRMS (ESI): m/z calcd for C24H25N3O5 [M + H]+: 436.1867; found:
436.1866.
HRMS (ESI): m/z calcd for C26H27N3O5 [M + H]+: 462.2023; found:
462.2023.
Diethyl 1-(4-Benzamido-8-bromonaphthalen-1-yl)hydrazine-1,2-
dicarboxylate (3ka)
White solid; yield: 42 mg (84%).
Diethyl 1-(4-Benzamido-8-phenylnaphthalen-1-yl)hydrazine-1,2-
dicarboxylate (3oa)
1H NMR (400 MHz, DMSO-d6):  = 10.63 (d, J = 10.1 Hz, 1 H), 9.59 (d,
J = 51.1 Hz, 1 H), 8.15–8.11 (m, 3 H), 8.07–7.95 (m, 2 H), 7.74 (d, J = 8.0
Hz, 1 H), 7.68–7.57 (m, 3 H), 7.49–7.44 (m, 1 H), 4.24–3.98 (m, 4 H),
1.29–1.01 (m, 6 H).
13C NMR (101 MHz, DMSO-d6):  = 166.8, 157.2, 157.1, 155.6, 155.1,
136.4, 136.1, 135.73, 135.71, 134.8, 134.53, 134.51, 132.8, 132.40,
132.38, 129.4, 129.2, 129.90, 128.98, 128.4, 128.3, 128.2, 127.9, 127.1,
127.0, 125.7, 125.0, 116.6, 62.54, 62.51, 61.8, 61.7, 15.1, 15.90, 14.95.
Light yellow solid; yield: 53.1 mg (92%).
1H NMR (400 MHz, DMSO-d6):  = 10.64–10.62 (m, 1 H), 8.18–8.13
(m, 3 H), 7.84–7.50 (m, 8.5 H), 7.43–7.31 (m, 3 H), 7.27–7.22 (m, 1 H),
7.12–7.09 (m, 0.5 H), 4.20–3.63 (m, 4 H), 1.21–1.00 (m, 6 H).
13C NMR (101 MHz, DMSO-d6):  = 166.9, 166.8, 156.2, 156.1, 154.4,
153.8, 143.1, 142.9, 138.4, 138.3, 137.0, 136.4, 135.2, 135.0, 134.8,
134.7, 132.33, 132.30, 131.7, 131.6, 131.4, 131.3, 129.00, 128.98,
128.6, 128.5, 128.37, 128.35, 128.2, 128.0, 127.7, 127.5, 127.2, 127.0,
125.8, 125.7, 124.8, 124.5, 124.3, 62.6, 62.1, 62.0, 14.9, 14.8, 14.6.
HRMS (ESI): m/z calcd for C23H22BrN3O5 [M + H]+: 500.0816; found:
500.0819.
HRMS (ESI): m/z calcd for C29H27N3O5 [M + H]+: 498.2023; found:
498.2024.
Diethyl 1-(4-Benzamido-8-methylnaphthalen-1-yl)hydrazine-1,2-
dicarboxylate (3la)
Brownish yellow powder; yield: 37.5 mg (86%).
Diethyl 1-(4-Benzamido-7-methoxynaphthalen-1-yl)hydrazine-
1,2-dicarboxylate (3pa)
Light yellow floc; yield: 43.0 mg (95%).
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2019, 51, A–H

G
Q.-Z. Li et al.
Special Topic
Synthesis
1H NMR (400 MHz, DMSO-d6):  = 10.52–10.33 (m, 2 H), 8.15–8.13
(m, 2 H), 8.00 (d, J = 9.2 Hz, 1 H), 7.70–7.39 (m, 6 H), 7.29–7.26 (m,
1H), 4.26–3.93 (m, 4 H), 3.96 (s, 3 H), 1.34–1.06 (m, 6 H).
13C NMR (101 MHz, DMSO):  = 166.8, 158.5, 157.0, 155.8, 135.8,
134.8, 134.7, 132.5, 132.2, 128.9, 128.3, 126.7, 126.1, 125.7, 121.7,
119.3, 102.2, 62.6, 61.7, 61.5, 55.9, 14.9.
Funding Information
This work was supported by the NSFC (No. 21672145, No. 21602131),
Shanghai Jiao Tong University (No. ZH2018QNA44, No. IPP18080) and
Department of Education of Guangdong Province (No.
2016KTSCX140).
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Supporting Information
Supporting information for this article is available online at
Diethyl 1-(4-Benzamido-6-methoxynaphthalen-1-yl)hydrazine-
1,2-dicarboxylate (3qa)
https://doi.org/10.1055/s-0037-1610705.
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Brownish yellow powder; yield: 43.5 mg (96%); mp: 183 °C.
1H NMR (400 MHz, DMSO-d6):  = 10.46 (s, 1 H), 10.31–9.94 (m, 1 H),
8.14–8.12 (m, 3 H), 7.66–7.54 (m, 5 H), 7.38–7.37 (m, 1 H), 7.33 (dd,
J = 9.3, 2.5 Hz, 1 H), 4.25–4.06 (m, 4 H), 3.88 (s, 3 H), 1.30–1.02 (m, 6
H).
13C NMR (101 MHz, DMSO):  = 166.8, 158.0, 156.8, 155.7, 137.0,
135.0, 133.4, 132.2, 131.6, 129.0, 128.3, 126.2, 126.0, 124.9, 123.0,
119.3, 102.8, 62.6, 61.7, 61.5, 55.7, 14.92, 13.89.
References
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HRMS (ESI): m/z calcd for C24H25N3O6 [M + H]+: 452.1816; found:
452.1819.
Di-tert-butyl 1-(4-Benzamidonaphthalen-1-yl)hydrazine-1,2-di-
carboxylate (3ab)
White flocs; yield: 26.3 mg (55%).
1H NMR (400 MHz, DMSO-d6):  = 10.52 (s, 1 H), 9.91–9.46 (m, 1 H),
8.20–8.12 (d, J = 7.5 Hz, 3 H), 8.03 (d, J = 7.9 Hz, 1 H), 7.65–7.57 (m, 7
H), 1.52–1.25 (m, 18 H).
13C NMR (101 MHz, DMSO-d6):  = 166.7, 155.9, 154.8, 154.4, 137.6,
134.8, 134.1, 133.9, 132.2, 130.7, 130.2, 128.9, 128.3, 126.6, 126.5,
125.7, 124.2, 124.0, 81.2, 80.7, 80.2, 28.5, 28.5, 28.3, 28.2.
HRMS (ESI): m/z calcd for C27H31N3O5 [M + H]+: 478.2336; found:
478.2339.
Diisopropyl 1-(4-Benzamidonaphthalen-1-yl)hydrazine-1,2-dicar-
boxylate (3ac)
Light yellow flocs; yield: 43.8 mg (98%).
(3) For selected examples for direct C–H functionalization of naph-
thalene derivatives, see: (a) Mal, D.; Pahari, P. Chem. Rev. 2007,
107, 1892. (b) Stuart, D. R.; Bertrand-Laperle, M.; Burgess, K. M.
N.; Fagnou, K. J. Am. Chem. Soc. 2008, 130, 16474. (c) Van
Otterlo, W. A. L.; de Koning, C. B. Chem. Rev. 2009, 109, 3743.
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Chem. Int. Ed. 2012, 51, 7242. (e) Ju, L.; Yao, J.; Wu, Z.; Liu, Z.;
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S. Z. Org. Biomol. Chem. 2014, 12, 3251. (g) Kondrashov, M.;
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1H NMR (400 MHz, DMSO-d6):  = 10.55 (s, 1 H), 10.20 (d, J = 10.8 Hz,
1 H), 8.21–8.14 (m, 3 H), 8.09–8.07 (m, 1 H), 7.73–7.68 (m, 2 H), 7.66–
7.58 (m, 5 H), 4.94–4.88 (m, 2 H), 1.35–1.01 (m, 12 H).
13C NMR (101 MHz, DMSO-d6):  = 166.8, 156.5, 155.4, 137.3, 137.1,
134.8, 134.4, 132.2, 130.8, 130.3, 129.0, 128.3, 127.0, 126.7, 125.7,
125.6, 124.2, 70.3, 69.0, 22.4, 22.1.
HRMS (ESI): m/z calcd for C25H27N3O5 [M + H]+: 450.2023; found:
450.2019.
Dibenzyl 1-(4-Benzamidonaphthalen-1-yl)hydrazine-1,2-dicar-
boxylate (3ad)
(4) For o-C–H functionalizations of naphthalene derivatives, see:
(a) Iwasaki, M.; Iyanaga, M.; Tsuchiya, Y.; Nishimura, Y.; Li, W.;
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M.; Raman, S.; Wendt, O. F. Chem. Commun. 2015, 51, 911.
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(a) Ng, K.-H.; Chan, A. S. C.; Yu, W.-Y. J. Am. Chem. Soc. 2010, 132,
12862. (b) Li, X.-T.; Gong, X.; Zhao, M.; Song, G.-Y.; Deng, J.; Li,
White flocs; yield: 52.9 mg (97%).
1H NMR (400 MHz, DMSO-d6):  = 10.69–10.24 (m, 2 H), 8.26–8.10
(m, 4 H), 7.83–7.16 (m, 17 H), 5.32–5.17 (m, 4 H).
13C NMR (101 MHz, DMSO-d6):  = 166.8, 156.8, 155.7, 136.7, 134.83,
134.81, 132.3, 130.8, 130.6, 130.4, 129.0, 128.9, 128.8, 128.6, 128.5,
128.45, 128.38, 128.0, 127.9, 127.2, 126.8, 125.8, 124.3, 124.2, 124.0,
67.9, 67.4, 67.0.
HRMS (ESI): m/z calcd for C33H27N3O5 [M + H]+: 546.2023; found:
546.2026.
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2019, 51, A–H

H
Q.-Z. Li et al.
Special Topic
Synthesis
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