nBu4NI-Mediated oxidation of methyl ketones to α-ketoamides: using ammonium, primary and secondary amine-salt as an amine moiety

Article abstract of DOI:10.1039/c7ob00270j

Presented here is the first example of synthesizing an array of primary-, secondary-, and tertiary-α-ketoamides with a non-metal catalyst nBu₄NI from methyl ketones and inexpensive readily available amine/ammonium salts; the reactions proceeded smoothly under mild conditions, TBHP was used as an oxidant and the corresponding α-ketoamides were afforded in moderate to excellent yields.

Full text of DOI:10.1039/c7ob00270j

View Article Online
View Journal
Organic &
Biomolecular
Chemistry
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: D. Wang, K.
Zhang, L. Jia, D. Zhang, Y. Zhang, Y. Cheng, C. Lin and B. Wang, Org. Biomol. Chem., 2017, DOI:
10.1039/C7OB00270J.
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Volume 14 Number
1 7 January 2016 Pages 1–372
Organic &
Biomolecular
Chemistry
www.rsc.org/obc
Accepted Manuscripts are published online shortly after
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
author guidelines.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the ethical guidelines, outlined
in our author and reviewer resource centre, still apply. In no
event shall the Royal Society of Chemistry be held responsible
for any errors or omissions in this Accepted Manuscript or any
consequences arising from the use of any information it contains.
ISSN 1477-0520
COMMUNICATION
Takeharu Haino et al.
Solvent-induced emission of organogels based on tris(phenylisoxazolyl)
benzene
rsc.li/obc

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 1 of 7
View Article Online
DOI: 10.1039/C7OB00270J
Journal Name
ARTICLE
nBu4NI-mediated oxidation of methyl ketones to α-ketoamides:
using ammonium, primary and secondary amine -salt as amine
moiety
Received 00th January 20xx,
Accepted 00th January 20xx
Dan Wang,a Kuan Zhang,a† Luhan Jia,a† Danꢀng Zhang,a† Yue Zhang,a Yujia Cheng,a Chang Lina*
DOI: 10.1039/x0xx00000x
and Bo Wanga,b
*
www.rsc.org/
Presented here is the first example of synthesizing an array of primary-, secondary-, and tertiary- α-ketoamides with a
non-metal catalyst nBu4NI from methyl ketones and inexpensive readily available amine/ammonium salts, the reactions
proceeded smoothly under mild conditions, TBHP was used as oxidant and the corresponding α-ketoamides were afforded
in moderate to excellent yields.
same protocol. In most reactions, heavy or noble metal catalysts
are involved and pollutions caused by heavy metals to
environment are associated, in addition, harsh conditions were
Introduction
α
-Ketoamides and their derivatives are key constituents in
usually required for reactions proceed smoothly. Therefore,
developing mental-free procedures for efficient preparations of
natural products and biologically relevant molecules, especially
as useful precursors for functional group transformations.1-3 Due
α
-ketoamides under mild conditions is highly desirable and
to their wide utilities
，the synthesis of α-ketoamides has
therefore is promising for sustainable developments and
potential for industrial purposes. Wang Z.Y. etal.15 developed a
novel approach using excess (2 equiv) catalyst nBu4NI or KI, aryl
methyl ketones and primary amines and NH4OAc were as the
starting materials via anodic oxidation assisted by electric
attracted considerable focuses in recent years. There has
developed a plethora of synthetic routes for the preparation of
α-ketoamides with varied reaction conditions and different
starting materials Fig ). Some used oxidative double
(
1
carbonylation reactions of monoalkylpalladium complexes or
halide in the presence of a Pd catalyst under a carbon monoxide
(CO) atmosphere, resulting in good yields and selectivities,
some use terminal alkynes, terminal alkenes or ethylarenes in
the presence of Cu or I2 catalyst,6-8 some employed α-
ketoaldehydes or α-keto acids along with amines catalysed by
silver, Cu, gold or Fe -catalyst to give their corresponding α-
ketoamides, 9-10 and some others used aryl methyl ketone, or 1-
arylethanols, or α-hydroxy ketones with Cu, Fe or I2 to provide α-
current to provide primary/secondary α-ketoamides with yields
4-5 varying from 5% to 90%. Qu L. B. etal.12b presented a procedure
using aryl methyl ketones and dialkylformamides catalysed by
nBu4NI (20%mol) to provide tertiary
harsh reaction conditions are involved
achievements in -ketoamides synthesis, there has been rare
α
-ketoamides, however,
.
Despite all the
α
examples that with a metal-free catalyst capable of providing
all primary-, secondary-, and tertiary- α-ketoamides.
ketoamides.11-13 We has recently developed
procedure using catalyst CuI with ethylarene and amines to
provide secondary, tertiary
-ketoamides,14 nevertheless, our
attempt for preparing primary -ketoamides failed with the
a
one-pot
R
R
X
R
R
α
α
R
O
R1
N
O
O
R2
H
O
R
R
OH
O
O
R
O
OH
R
OH
R
O
Fig 1 Selected examples for α-ketoamides synthesis with varied starting
materials
Herein, we present an nBu4NI-mediated synthesis of α-
ketoamides via C-H activation using tbutylhydroperoxide
(TBHP) as the oxidant, aryl methyl ketones and amine- or
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 1
Please do not adjust margins

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 2 of 7
View Article Online
DOI: 10.1039/C7OB00270J
ARTICLE
Journal Name
ammonium- salts are as the starting materials under mild 3ab could be obtained in moderate to excellent yields. After that,
conditions (Scheme 1) to yield the desired product primary-, an array of iodide-containing reagents was investigated for a
secondary-, and tertiary- α-ketoamides with yields of up to possibly suitable catalyst, to our disappointed, the oxidative
96%. Representing the first example using metal-free catalyst coupling product 3ab was obtained in an unexpected low yield
to provide all types of α-ketoamides.
O
of 59% when using CuI as the catalyst (Entry 1, Table 1), as to KI
and I2, similar results were afforded as those reactions from
using CuI under the same conditions (Entry 2, 3, Table 1), among
of them, nBu4NI proved itself the most efficient catalyst (Entry 4,
Table 1). The temperature had much affection on product yields
(Entry 4-8, Table 1) as when temperature increased to 50oC, the
yield of desired product 3ab significantly increased to 96% (Entry
4, Table 2). Control experiments (Entry 9-11, Table 1) revealed
that an oxidant (Entry 9, Table 1), an iodide-containing catalyst
(Entry 10, Table 1) and a base (Entry 11, Table 1) are all
NH2
Ar
O
O
Ar
l
C
H3
N
R1
O
R3
N
O
H
N
Ar
R2
Ar
R1
necessary for the formation of α-ketoamidates. Simply
increasing the loading of catalyst and/or oxidant could not result
O
O
in improved yields (Entry 12, 13, Table 1). The effect of solvent
Scheme 1 Synthesis of primary, secondary, and tertiary α-ketoamides
using catalyst nBu4NI
Table2. Optimization of reaction conditions of synthesis of Primary α-
ketoamides with catalyst nBu4NI from aryl methyl ketone and
ammonium hydrochloridea
Results and discussion
Initial investigations for optimized reaction conditions were
carried out by employing acetophenone and ethylamine
hydrochloride as the model substrates, reaction parameters
such as catalysts, reaction temperatures, oxidants and their
Solvent. Loading
Entry
Catalyst
Base(mmol)
Yieldb(%)
(mL)
0.2
0.2
0.2
0.2
0.2
0.3
0.4
0.4
0.4
0.4
0.4
0.4
0.4
1
nBu4NI
nBu4NI
nBu4NI
I2
K2CO3(1.1)
CaCO3(1.1)
38
25
Table 1 Optimization of reaction conditions of synthesis of secondary/
tertiary α-ketoamides with catalyst nBu4NI from aryl methyl ketone and
primary/ secondary amine hydrochloridea
2
3
NaHCO3(1.1)
NaHCO3(1.1)
NaHCO3(1.1)
NaHCO3(1.1)
NaHCO3(1.1)
NaHCO3(1.3)
NaHCO3(1.5)
NaHCO3(2.0)
NaHCO3(1.5)
NaHCO3(1.5)
NaHCO3(1.5)
41
4
19
5
KI
27
6
nBu4NI
nBu4NI
nBu4NI
nBu4NI
nBu4NI
nBu4NI
nBu4NI
nBu4NI
56
Entry
1
2
3
4
5
6
7
8
Catalyst T (oC) Solvent Base
Oxidant Yieldb(%)
7
62
CuI
KI
50
50
50
50
60
70
80
40
50
50
50
50
50
50
50
50
50
50
50
50
50
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
THF
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
--
TBHP
TBHP
TBHP
TBHP
TBHP
TBHP
TBHP
TBHP
--
TBHP
TBHP
TBHP
TBHP
TBHP
TBHP
TBHP
TBHP
TBHP
TBHP
O2
59
82
76
96
88
83
79
85
Trace
0
Trace
95
92
79
82
68
26
8
75
9
89
I2
10
11c
12d
13e
64
nBu4NI
nBu4NI
nBu4NI
nBu4NI
nBu4NI
nBu4NI
--
Trace
31
37
aConditions: Aryl methyl ketone 1a, 1.0 mmol; ammonium chloride, 2.0
mmol; catalyst, 0.1mmol (10%mmol); Base; Oxidant 5 mmol (70 wt%
TBHP in water); Solvent, DMSO; Temperature, 50oC. bYields were
determined by HPLC analysis at the wavelength of 254 nm. cNH4CO3 was
used instead. dNH4SO4 was used. eNH4OAc was used here.
9
10
11
12c
13d
14
15
16
17
18
19
20
21
nBu4NI
nBu4NI
nBu4NI
nBu4NI
nBu4NI
nBu4NI
nBu4NI
nBu4NI
nBu4NI
nBu4NI
nBu4NI
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
CaCO3
Na2CO3
NaHCO3
K2CO3
CaCO3
also evaluated, results indicated that when reactions were
proceeded in tetrahydrofuran (THF), N, N-Dimethylformamide
(DMF), and Acetonitrile (ACN) (Entry 14-16, Table 1), low
product yields were resulted. After evaluation of a range of
bases, the results disclosed that K2CO3 performed the best over
DMF
ACN
DMSO
DMSO
DMSO
DMSO
DMSO
65
74
42
23
H2O2
other bases, CaCO3, Na2CO3 and NaHCO3. Meanwhile
,
TBHP
could provide higher yield compared with those using O2 or
H2O2(Entry 4, Entry 20, 21, Table 1
aConditions: Aryl methyl ketone 1a, 1.0 mmol; Ethylamine hydrochloride
2a, 1.2 mmol; Base, 1.1 mmol; Catalyst, 10mol%; Oxidant, 5 mmol (70 wt%
TBHP in H2O); Solvent, 0.2mL. Yields were determined by HPLC analysis
)
.
b
With the optimized conditions, we wish to possibly extend the
substrate scope for oxidative coupling of various substituted aryl
methyl ketones with different primary amine hydrochloride
listed in Table 3. All reactions were proceeded smoothly to
afford the desired products, results indicated that in most
equipped with a Vertex C18 column at the wavelength of 254 nm.
cReaction was carried out with 10 equivalents of TBHP. dWith nBu4NI of
20%.
loadings, and co-solvents were evaluated, and the results were
summarized in Table 1. In most reactions, the desired product
2 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 3 of 7
View Article Online
DOI: 10.1039/C7OB00270J
Journal Name
ARTICLE
conditions, when aryl methyl ketones bearing an electron-rich or more steric hindered piperidine hydrochloride gave the desired
electron-deficient substituent, their corresponding secondary α- α-ketoamides 4ca and 4cb in yields of 44% and 51%, respectively
ketoamides could be afforded in moderate to excellent yields of at 50oC. We thought that low conversions may possibly due to
up to 96%. It is noteworthy that when employing substrate with the increased steric hindrance of amine moieties. When ketones
a chloride substituent on aromatic ring, the generated product bearing an electron-withdrawing or electron-donating
was provided in poorer yields compared with those without substituent, better yields were resulted (4ab-4ad, 4bb).
chloride substituent (3ca and 3cb). In addition, more steric
Given the prevalence of the primary α-ketoamides in
hindered amine salts could also react well with aryl methyl biological pharmaceutical, there have been very limited
ketones to afford products in good yields (3ac, 3ad and 3bd).
examples for primary α-ketoamides synthesis, we would like to
further extend our approach to prepare primary α-ketoamides.
Table 3 Synthesis of secondary/tertiary α-ketoamides catalysed by Initially, we use the same conditions developed for secondary
nBu4NI using aryl methyl ketone and primary/secondary amine and tertiary α-ketoamides to check the possibility for primary α-
hydrochloridea
ketoamide 5a synthesis, the yield is provided in 38% (Entry 1
Table 2) after reaction. Base may possibly be considered to have
some effects on such reactions to improve the product yields,
therefore, several bases such as CaCO3, K2CO3, NaHCO3, SeCO3,
Na2CO3, NaOH, and KOH (not all of them in Table 2) were then
Table 4 Synthesis of primary α-ketoamides catalysed by nBu4NI from
aryl methyl ketone and ammonium hydrochloridea
aReaction were performed on at a 1mL scale, conditions: Aryl methyl
ketone 1a, 1.0 mmol; ammonium hydrochloride, 2.0 mmol; nBu4NI,
0.1mmol (10% mol); NaHCO3, 1.5mmol; Oxidant 5 mmol (70 wt% TBHP
in water,); Solvent, 0.4mL. Yields were determined by HPLC analysis
equipped with a C18 column.
evaluated, and finally NaHCO3 proved itself the best among of all
tested bases (Entry 3 Table 2). Also, catalysts such as nBu4NI, I2,
KI and CuI were investigated again for more suitable one. To our
delight, nBu4NI performed better than all, the yield was slightly
increased to 41% (Entry3 Table 2) with NaHCO3, no obvious
improvement was observed, we think possibly this may due to
the low solubility of 5a in DMSO(0.2mL), more solvent was
applied to check whether improved yield could be provided, and
the results were listed in Table 2, results indicated that the
loading of solvent played an important role in 5a synthesis (Entry
5,6 Table 2). Varied ratios of base: aryl methyl ketone were
investigated for more suitable conditions to improve the yield of
aReactions were performed on at a 1mL scale, conditions: Aryl methyl
ketone
nBu4NI, 0.1mmol (10%mol); K2CO3, 1.1 mmol; TBHP, 5 mmol (70 wt% in
water), DMSO, 0.2mL, temperature, 50oC
Yields were determined by
HPLC analysis equipped with a C18 column.
1, 1.0mmol; primary/secondary amine hydrochloride 2, 1.2 mmol;
.
Encouraged by efficient synthesis of secondary α-ketoamides
from primary amine salts, the scope of the reaction was further
extended to more challenging tertiary α-ketoamides synthesis
using secondary amines salts (Table 3). As expected, most of the
products could be provided in good to excellent yields. However,
the reaction of acetophenone and p-methyl acetophenone with
5a, and the ratio 1:1.5 proved to be the best (Entry 9 Table 2
and will be chosen in future evaluations. Several ammonium
salts, such as ammonium carbonate (Entry 11 Table ),
)
2
ammonium sulfate (Entry 12 Table 2), and ammonium acetate
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 4 of 7
View Article Online
DOI: 10.1039/C7OB00270J
ARTICLE
Journal Name
was considered that aryl methyl ketones may be demethylated
under the oxidative conditions.
(Entry 13 Table 2) were also explored as suitable amine source.
Finally ammonium chloride we initially used gave better yield in
5a synthesis.
With the optimized reaction conditions in hand, an array of
primary α-ketoamides were obtained in moderate to good yields
(
(
Table 4). Generally, ketone with electron-neutral or -rich group
5a, 5b, 5c, 5g) provided better yields than ketone bearing
electron-deficient group (5d, 5e, 5f). Substituent at different
positions on phenyl ring could also affect the yields of products
to some extent. When a substituted group is at the para position
(
5b), substrate displayed more reactive than that with a
substituent at the meta position (5c), the reason for this may
possible be attributed to weak electron supplies. We did not
observe any negative effects on product yield when using more
steric hindered substrate (5g).
%
To further explore the substrate scope, heteroaromatic
substrates were also employed with the reported conditions,
however, heteroaromatic substrates do not provide adequate
yields.
Fig 2 Control experiments to test the proposed mechanism
To verify this, control reaction using acid
6 coupled with
ethylamine hydrochloride under the conditions in the foot note
of Table 1 was investigated. However, product 3ba was not
tBuO
tBuOOH
+
(a)
HO
detected, indicating that
catalyzed radical oxidative transformations (Fig. 2 d). And next,
radical and free amine coupled to form the intermediate , a
hydrogen atom (C-H) from intermediate is trapped by a tert-
butoxyl radical to from radical . which is further oxidized by
6 was not the intermediate for nBu4NI-
A
D
1/2 I2
I
D
E
TBHP to finally form the desired product. Based on the above
+
H2O
tBuOOH
tBuOO or tBuO
HO
tBuOO
+
observations and some researches on the ‘nBu4NI-TBHP’’
17a
a plausible mechanism for radical oxidative
system,12b,
O
(b)
(c)
(d)
O
R1
CH2
CH3
R1
coupling reaction is proposed and illustrated in Scheme 2.
A
tBuOOH or tBuOOH
Conclusions
R2
R3
R2
base
N
H.HCl
N
H
In summary, we have developed an efficient and
environmentally friendly approach to prepare a range of
aromatic α-ketoamides using a non-metal catalyst nBu4NI in
moderate to excellent yields, which are important structural
units in a plethora of biological compounds or drugs. Easily
commercial obtainable ketones and amine salts are used as
the starting materials, and reactions were proceeded smoothly
well under mild conditions. To the best of our knowledge, we
have, for the first time, successfully achieved the formation of
primary-, secondary-, and tertiary- α-ketoamidions by
oxidative amidation of ketones with inexpensive
amine/ammonium salts and a non-metal catalyst nBu4NI. This
α-ketoamides synthetic approach is believed to provide us an
alternative for the synthesis of α-ketoamides, and therefore it
is potential for practical and sustainably industrial applications.
Further optimisation of the conditions for heteroaromatic
substrates so that these substrates can be utilized is underway.
R3
B
O
R2
N
R2
R3
O
N
H
R3
+
R1
R1
CH2
O
F
B
A
TBHP
R2
O
R2
N
O
R2
N
O
O
R2
N
tBuO
R3
TBHP, tBuO
R3
TBHP
N
R3
R3
R1
R1
R1
R1
OH
D
E
Scheme 2. Possible mechanism for radical oxidative coupling reactions
A
plausible mechanism for radical oxidative coupling is
proposed in Scheme 2. The catalytic cycle was proposed as
shown in Scheme 2 (a): In the first step, the tert-butoxyl and
tert-butylperoxyl radical formed catalytically assisted with I-
released from catalyst nBu4NI.16 The resulted tert-butoxyl or
tert-butylperoxyl radical trap a hydrogen atom from the aryl
methyl ketone to generate radical
A (Scheme 4 (b
)).17 To verify
Experimental section
the formation of a free amine, several control experiments were
performed under the same conditions described in the foot note
of Table 1 (Fig. 2). Free amine released from amine salt with the
General Methods
All chemicals were commercially available and purchased from
Aladdin (Shanghai, China) and were used as received without
any further purification. All chemicals used were of analytical
assistance of base18 was introduced, and the free amine was
lively which can be combined with a lot of reactants.19 Firstly, it
4 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 5 of 7
View Article Online
DOI: 10.1039/C7OB00270J
Journal Name
ARTICLE
grade. 1H NMR and 13C NMR spectrum were recorded on a CDCl3): δ = 186.01, δ = 161.18, δ = 150.84, δ = 137.93, δ = 132.37,
Bruker Avance 400 instrument, 400 MHz for 1H NMR and 100 δ = 123.48, δ = 26.19.
MHz for 13C NMR. All chemical shifts (δ) were quoted in parts N-ethyl-2-oxo-2-phenylacetamide (3ab)21 Yellow oil 1H NMR
per million (ppm) and reported relative to an internal (400 MHz, CDCl3): δ = 8.22 (d, J = 4.0Hz, 2H), δ = 7.52 (d, J =
tetramethylsilane (TMS,
δ 0.00) standard. The following 4.0Hz, 1H), δ = 7.38 (t, J = 4.0Hz 2H), δ = 3.36-3.31 (m, 2H). δ =
abbreviations were used to explain the multiplicities: s = singlet, 1.15(t, J = 4.0Hz, 3H). 13C NMR (100 MHz, CDCl3): δ = 188.31, δ =
d = doublet, t =triplet, q =quartet, m = multiplet. Yields of 162.25, δ = 134.26, δ = 133.33, δ = 130.96, δ = 128.41, δ = 34.31,
products were measured by HPLC analysis using SHIMADZU δ = 14.36.
instrument equipped with a column Wonda Sil C18-WR 5μm. N-ethyl-2-oxo-2-(p-tolyl)acetamide (3bb) Yellow solid 1H NMR
HRMS spectrum were recorded on a Shimadzu LCMS-IT-TOF (400 MHz, CDCl3), δ = 8.24 (d, J = 8.0Hz, 2H), δ = 7.26 (d, J =
instrument.
8.0Hz, 2H). δ = 3.46-3.39 (m, 2H), δ = 2.41(s, 3H)δ = 1.23 (t, J =
4.0Hz, 3H). 13C NMR (100 MHz, CDCl3): δ = 187.57, δ = 162.14, δ
= 145.52, δ = 131.31, δ = 130.89, δ = 129.21, δ = 34.32, δ = 21.32,
δ = 14.47. HRMS m/z (APCI) Calcd for C11H13NO2 (M + H)+
192.1019, found 192.1001.
General procedures for the synthesis of secondary /tertiary α-
Ketoamides.
A mixture of Aryl methyl ketone 1.0mmol and ethylamine
hydrochloride 1.2 mmol; nBu4NI 0.1 mmol (10%mmol); TBHP
5mmol (70 wt% in water); K2CO3 1.1mmol; in DMSO 0.2 mL was
stirred at 50oC till almost completed conversion of the
substrates by TLC analysis, the action mixture was cooled to
room temperature, and then extracted with ethyl acetate (50 mL
× 3). The combined organic layers were washed with brine
solution and dried over anhydrous MgSO4. And the yields were
determined by HPLC analysis equipped with a C18 column. The
solvent was removed, and the residue was purified with
chromatography column on silica gel using hexane/ethyl acetate
(5:1) as eluent to give the corresponding product.
2-(4-chlorophenyl)-N-ethyl-2-oxoacetamide (3cb) Yellow solid
1H NMR (400 MHz, CDCl3): δ = 8.265 (d, J = 8.0Hz, 2H), δ =7.40 (d,
J = 8.0Hz, 2H), δ = 3.43-3.36 (m, 2H), δ = 1.21 (t, J = 8.0Hz, 3H).
13C NMR (100 MHz, CDCl3): δ = 186.59, δ = 161.48, δ = 141.00, δ
= 132.59, δ = 131.68, δ = 128.79, δ = 34.40, δ = 14.40. HRMS m/z
(APCI) Calcd for C10H10ClNO2 (M + H)+ 212.0473, found
212.0429.
N-ethyl-2-(4-nitrophenyl)-2-oxoacetamide (3db) Yellow solid 1H
NMR (400 MHz, CDCl3): δ = 8.55 (d, J = 8.0Hz, 2H), δ = 8.33 (d, J =
8.0Hz, 2H), δ = 3.49 (q, J = 8.0Hz 2H), δ = 3.09(t, J = 8.0Hz, 3H).
13C NMR (100 MHz, CDCl3): δ = 186.25, δ = 160.41, δ = 150.81, δ
= 138.00, δ = 132.41, δ = 123.45, δ = 34.60, δ = 14.44. HRMS m/z
(ESI) Calcd for C10H10N2O4 (M - H)- 221.0568, found 221.0548.
2-oxo-N,2-diphenylacetamide (3ac)22 Yellow oil 1H NMR (400
MHz, CDCl3): δ = 9.07 (s, 3H), δ = 8.44 (d, J = 8.0Hz, 2H), δ = 7.75
(d, J = 8.0Hz, 2H), δ = 7.69 (t, J = 4.0Hz, 1H), δ = 7.54 (t, J = 8.0Hz,
2H), δ = 7.43 (t, J = 8.0Hz, 2H), δ = 7.23 (t, J = 4.0Hz, 1H). 13C
NMR (100 MHz, CDCl3): δ = 187.52, δ = 159.05, δ = 136.71, δ =
134.65, δ = 131.48, δ = 129.24, δ = 128.59, δ = 125.32, δ =
120.02.
N-cyclohexyl-2-oxo-2-phenylacetamide (3ad)23 light Yellow solid
1H NMR (400 MHz, CDCl3):, δ = 8.35 (d, J = 8.0Hz, 2H), δ = 7.64 (t,
J = 8.0Hz, 1H), δ = 7.49 (t, J = 8.0Hz, 2H), δ = 3.88 (d, J = 8.0Hz,
1H), δ =2.01 (d, J = 12.0Hz, 2H), δ = 1.80-1.77 (m, 2H), δ = 169-
166 (m, 1H), δ = 3.03 (dd, J = 12.0Hz, 2H), δ = 1.35-1.23 (m, 3H).
13C NMR (100 MHz, CDCl3), δ = 188.19, δ = 160.93, δ = 134.30, δ
= 133.48, δ = 131.22, δ = 128.46, δ = 48.49, δ =32.72, δ = 25.44,
δ = 24.77.
N-cyclohexyl-2-oxo-2-(p-tolyl)acetamide (3bd)23 light Yellow
solid 1H NMR (400 MHz, CDCl3): δ = 8.23 (d, J = 8.0Hz, 2H), δ =
7.25 (d, J = 8.0Hz, 2H), δ =3.84 (dd, J = 8.0Hz, J = 4.0Hz 1H), δ =
2.40 (s, 3H), δ = 1.97 (d, J = 12.0Hz, 2H), δ = 1.76-1.73 (m, 2H), δ
= 1.63 (d, J = 12.0Hz, 1H), δ = 1.40 (dd, J = 8.0Hz, J = 4.0Hz 2H), δ
= 1.26-1.18 (m, 3H). 13C NMR (100 MHz, CDCl3): δ = 187.74, δ =
161.34, δ = 145.41, δ = 131.33, δ = 130.97, δ = 1229.17, δ =
48.43, δ =32.67, δ = 25.43, δ = 24.79 δ = 24.79, δ = 21.83.
N,N-dimethyl-2-oxo-2-phenylacetamide (4aa)21 Yellow oil 1H
NMR (400 MHz, CDCl3): δ =7.80 (d, J = 4.0Hz, 2H), δ = 7.28 (d, J =
8.0Hz, 2H), δ = 3.07 (s, 2H), δ = 2.92(s, 3H), δ = 2.87(s, 3H). 13C
NMR (100 MHz, CDCl3): δ = 191.60, δ = 167.28, δ = 146.03, δ =
130.58, δ = 129.75, δ = 129.71, δ = 37.02, δ = 33.90, δ = 21.87.
General procedures for the synthesis of primary α-Ketoamides.
A mixture of Aryl methyl ketone 1.0 mmol; Ammonium
chloride 2.0 mmol; nBu4NI 0.1 mmol (10%mmol); TBHP 5mmol
(70 wt% in water); NaHCO3 1.5mmol; in DMSO 0.4 mL was
stirred at 50oC till almost completed conversion of the
substrates by TLC analysis, the action mixture was cooled to
room temperature, and then extracted with ethyl acetate (50 mL
× 3). The combined organic layers were washed with brine
solution and dried over anhydrous MgSO4. And the yields were
determined by HPLC analysis equipped with a C18 column. The
solvent was removed, and the residue was purified with
chromatography column on silica gel using hexane/ethyl acetate
(5:1) as eluent to give the corresponding product.
N-methyl-2-oxo-2-phenylacetamide (3aa)20 Yellow oil, 1H
NMR (400 MHz, CDCl3): δ =8.27 (d, J = 4.0Hz, 2H), δ =7.57 (d, J =
4.0Hz, 1H), δ = 7.43 (t, J = 4.0Hz 2H), δ = 2.91(d, J = 8.0Hz,
3H).13C NMR (100 MHz, CDCl3): δ = 188.31, δ = 162.25, δ =
134.26, δ = 133.33, δ = 130.96, δ = 128.41, δ = 34.31, δ = 14.36.
N-methyl-2-oxo-2-(p-tolyl)acetamide (3ba)20 Yellow solid 1H
NMR (400 MHz, CDCl3): δ = 8.19 (d, J = 8.0Hz, 2H), δ =7.22 (d, J =
8.0Hz, 2H), δ = 2.915 (d, J = 4.0Hz, 3H), δ = 2.37 (s, 3H). 13C NMR
(100 MHz, CDCl3): δ = 187.49, δ = 163.12, δ = 145.52, δ = 131.22,
δ = 130.83, δ = 129.21, δ = 25.94, δ = 21.81.
N-(4-chloride)-2-oxo-2-(p-tolyl)acetamide (3ca)20 Yellow solid
1H NMR (400 MHz, CDCl3): δ =8.29 (d, J = 8.0Hz, 2H), δ = 7.425
(d, J = 12.0Hz, 2H), δ = 2.915 (d, J = 4.0Hz, 3H). 13C NMR (100
MHz, CDCl3): δ = 186.38, δ = 162.26, δ = 141.10, δ = 132.62, δ =
131.65, δ = 128.85, δ = 26.04.
N-methyl-2-(4-nitrophenyl)-2-oxoacetamide (3da)20 Yellow solid
1H NMR (400 MHz, CDCl3):, δ = 8.57 (d, J = 8.0Hz, 2H), δ = 8.34 (d,
J = 8.0Hz, 2H).δ = 3.03 (d, J = 4.0Hz, 3H). 13C NMR (100 MHz,
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 5
Please do not adjust margins

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 6 of 7
View Article Online
DOI: 10.1039/C7OB00270J
ARTICLE
Journal Name
1
N,N-dimethyl-2-oxo-2-(p-tolyl)acetamide (4ba)21 Yellow solid H = 135.60, δ = 133.30, δ = 130.30, δ = 129.33. δ = 127.45, δ = 21.
NMR (400 MHz, CDCl3): δ =7.92 (d, J = 4.0Hz, 2H), δ = 7.62 (t, J = 28.
4.0Hz, 1H), δ = 7.49 (t, J = 8.0Hz 2H), δ = 3.09(s, 3H), δ = 2.93(s, 2-(4-fluorophenyl)-2-oxoacetamide (5d)15 Yellow solid 1H NMR
3H). 13C NMR (100 MHz, CDCl3): δ = 191.86, δ = 167.07, δ = (400 MHz, DMSO-d6):, δ = 8.37 (s, 1H), δ = 8.11 (t, J = 8.0Hz, 2H),
134.77, δ = 133.02, δ = 129.61, δ = 129.04, δ = 37.02, δ = 33.95.
δ = 8.05 (s, 1H), δ = 7.43 (t, J = 8.0Hz, 2H). 13C NMR (100 MHz,
2-(4-chlorophenyl)-N,N-dimethyl-2-oxoacetamide (4ca)21 Yellow DMSO-d6): δ = 189.51, δ = 167.17, δ = 164.88, δ = 133.38, δ =
solid 1H NMR (400 MHz, CDCl3): δ = 7.85 (d, J = 8.0Hz, 2H), δ = 130.02, δ = 116.72.
7.44 (d, J = 8.0Hz, 2H), δ = 3.07 (s, 3H), δ = 2.92 (s, 3H). 13C NMR 2-(4-chlorophenyl)-2-oxoacetamide (5e)26 Yellow solid 1H NMR
(100 MHz, CDCl3): δ = 190.35, δ = 166.49, δ = 141.25, δ = 131.45, (400 MHz, DMSO-d6):, δ = 8.37 (s, 1H), δ = 8.07 (s, 1H), δ = 8.04-
δ = 130.99, δ = 129.38, δ = 37.00, δ = 34.02.
8.008 (m, 2H), δ = 7.69-7.66 (m, 2H). 13C NMR (100 MHz, DMSO-
N,N-dimethyl-2-(4-nitrophenyl)-2-oxoacetamide (4da)21 Yellow d6): δ = 189.82, δ = 166.93, δ = 139.90, δ = 132.04, δ = 132.01, δ
solid 1H NMR (400 MHz, CDCl3): δ = 8.35 (d, J = 8.0Hz, 2H), δ = = 129.60.
8.15 (d, J = 8.0Hz, 2H), δ = 3.10 (s, 3H), δ = 3.08 (s, 3H). 13C NMR 2-(4-bromophenyl)-2-oxoacetamide (5f)27 Yellow solid 1H NMR
(100 MHz, CDCl3), δ = 189.32, δ = 165.63, δ = 151.56, δ = 137.56, (400 MHz, DMSO-d6):, δ =8.37 (s, 1H), δ = 8.06 (s, 1H).δ = 7.94
δ = 130.81, δ = 124.10, δ = 37.09, δ = 34.30.
(m, 2H), δ = 7.82 (m, 2H). 13C NMR (100 MHz, DMSO-d6): δ =
N,N-diethyl-2-oxo-2-phenylacetamide (4ab)23 Yellow oil 1H NMR 190.08, δ = 166.95, δ = 132.59, δ = 132.31, δ = 132.09, δ =
(400 MHz, CDCl3):, δ = 7.92 (d, J = 8.0Hz, 1H), δ = 7.62 (t, J = 129.22.
8.0Hz, 2H), δ = 7.49 (t, J = 8.0Hz, 2H),δ = 3.55(q, J = 8.0Hz,2H ), δ 2-(naphthalen-2-yl)-2-oxoacetamide (5g)15 Yellow solid H NMR
1
= 3.23(q, J = 8.0Hz,2H ), δ = 1.27 (t, J = 4.0Hz, 3H), δ = 1.13 (t, J = (400 MHz, DMSO-d6): δ = 8.88 (d, J = 8.0Hz 1H), δ = 8.53 (s, 1H).δ
4.0Hz, 3H). 13C NMR (100 MHz, CDCl3): δ = 191.64, δ = 166.76, δ = 8.14 (d, J = 8.0Hz, 2H), δ = 8.09 (d, J = 8.0Hz, 1H), δ = 7.76-7.64
= 134.61, δ = 133.22, δ = 129.57, δ = 128.98, δ = 42.12, δ = 38.80, (m, 4H). 13C NMR (100 MHz, DMSO-d6), δ = 194.16, δ = 168.08, δ
δ = 14.08, δ = 12.83.
= 135.19, δ = 133.98, δ = 133.70, δ = 130.77, δ = 129.36, δ
N,N-diethyl-2-oxo-2-(p-tolyl)acetamide (4bb)23 Yellow solid 1H =129.17δ =127.24, δ = 125.41, δ = 125.29.
NMR (400 MHz, CDCl3): δ =7.68 (d, J = 8.0Hz, 2H), δ = 7.15 (d, J = 2-(3-methoxyphenyl)-2-oxoacetamide (5h)26 Yellow solid 1H
8.0Hz, 2H), δ = 3.40 (q, J = 8.0Hz, 2H), δ = 3.08 (q, J = 8.0Hz, 2H), NMR (400 MHz, DMSO-d6): δ = 8.03 (s, 1H), δ = 7.52-7.48 (m,
δ = 2.26(s, 3H), δ = 1.13(t, J = 8.0Hz, 3H), δ = 0.98(t, J = 8.0Hz, 1H).δ = 7.44 (s, 1H), δ = 7.33 (t, J = 8.0Hz, 2H), δ = 3.82 (s, 3H).
3H). 13C NMR (100 MHz, CDCl3), δ = 191.27, δ = 166.82, δ = 13C NMR (100 MHz, CDCl3), δ = 168.22, δ = 159.62, δ = 136.19, δ
145.69, δ = 130.69, δ = 129.59, δ = 129.49, δ = 42.99, δ = 38.63, = 129.79, δ = 120.18, δ = 117.52, δ = 113.15, δ = 55.66. 13C NMR
δ = 21.66, δ = 13.95, δ = 12.69.
(100 MHz, DMSO-d6): δ =187.74, δ = 161.34, δ = 145.41, δ =
1-phenyl-2-(piperidin-1-yl)ethane-1,2-dione (4ca)24 Yellow solid 131.33, δ = 130.97, δ = 129.17, δ = 48.43, δ =32.67, δ = 25.43, δ
1H NMR (400 MHz, CDCl3):, δ = 7.95 (d, J = 8.0Hz, 2H), δ = 7.66- = 24.79, δ = 21.83.
7,62 (m, 1H), δ = 7.52 (t, J = 4.0Hz, 2H), δ = 3.71(s, , 2H), δ = 3.31- 2-(4-ethylphenyl)-2-oxoacetamide (5i) Yellow solid 1H NMR (400
3.28 (m, 2H), δ = 1.71-1.68 (m, 4H), δ = 1.55 (d, J = 4.0, 2H). 13C MHz, DMSO-d6):, δ = 8.31 (s, 1H), δ = 7.96 (s, 1H).δ = 7.91 (m,
NMR (100 MHz, CDCl3), δ = 191.97, δ = 165.47, δ = 134.65, δ = 2H), δ = 7.43 (d, J = 8.0Hz, 2H), δ = 2.70 (q, J = 8.0Hz, 2H).δ = 1.21
133.29, δ = 129.54, δ = 129.01, δ = 47.03, δ =42.15, δ = 26.19, δ (t, J=8.0Hz, 3H). 13C NMR (100 MHz, DMSO-d6), δ =190.97, δ =
= 25.44, δ = 24.36.
167.89, δ = 151.74, δ = 130.96, δ = 130.37, δ = 128.86, δ = 28.81,
1-(piperidin-1-yl)-2-(p-tolyl)ethane-1,2-dione (4cb)25 Yellow δ = 15.57. HRMS m/z (ESI) Calcd for C10H11NO2 (M + Na)+
solid 1H NMR (400 MHz, CDCl3):, δ = 7.32 (d, J = 8.0Hz, 2H), δ = 200.0682, found 200.0648.
7.29 (t, J = 8.0Hz, 2H), δ = 3.63 (s, 2H), δ = 3.27-3.24 (m, , 2H), δ =
2.41 (s, 3H), δ = 1.67 (s, 4H), δ = 1.53 (d, J = 12.0, 3H) δ = 1.24-
1.20 (m, 1H). 13C NMR (100 MHz, CDCl3), δ = 191.73, δ = 165.66,
δ = 145.91, δ = 130.29, δ = 129.73, δ = 129.65, δ = 47.01, δ
=42.07, δ = 26.18, δ = 25.44, δ = 24.36, δ = 21.87.
Acknowledgements
Financial support from the National Natural Science
Foundation of China (21502036), Innovative research team
project of Hainan Natural Science Foundation (2016CXTD006),
Hainan Provincial Natural Science Foundation (20165191) and
Hainan University (kyqd1408) are greatfully acknowledged.
1
2-oxo-2-phenylacetamide (5a)26 Yellow solid H NMR (400 MHz,
DMSO-d6): δ = 8.37 (s,1H), δ = 8.01 (d, J = 4.0Hz, 3H), δ = 7.74 (t,
J = 4.0Hz, 1H), δ = 7.62 (s, J = 4.0Hz, 2H). 13C NMR (100 MHz,
DMSO-d6), δ = 191.31, δ = 167.67, δ = 134.94, δ = 133.24, δ =
130.23, δ = 129.42.
2-oxo-2-(p-tolyl)acetamide (5b)15 Yellow solid 1H NMR (400 MHz,
DMSO-d6):, δ = 8.32 (s, 1H), δ = 7.97 (s, 1H), δ = 7.91 (d, J = 8.0Hz,
2H), δ = 7.41 (d, J = 8.0Hz, 2H) δ = 2.42 (s, 3H) 13C NMR (100 MHz,
DMSO-d6), δ = 190.91, δ = 167.83, δ = 145.67, δ = 130.78, δ =
130.26, δ = 129.98, δ = 21.82.
Notes and references
1
a) M. Hagihara and S. L. Schreiber, J. Am. Chem. Soc., 1992,
114, 6570; b) H. Tanaka, A. Kuroda, H. Marusawa, H.
Hatanaka, T. Kino, T. Goto, M. Hashimoto and T. Taga, J. Am.
Chem. Soc., 1987, 109, 5031. c) D. H. Slee, K. L. Laslo, J. H.
Elder, I. R. Ollmann, A. Gustchina, J. Kervinen, A. Zdanov, A.
2-oxo-2-(m-tolyl)acetamide (5c)15 Yellow solid 1H NMR (400
MHz, DMSO-d6): δ =8.35 (s, 1H), δ =8.00 (s, 1H), δ =7.80 (s, 2H) δ
Wlodawer and C. H. Wong, J. Am. Chem. Soc., 1995, 117
11867. d) Z. Z. Li, A. C. OrtegaVilain, G. S. Patil, D. L. Chu, J. E.
Foreman, D. D. Eveleth and J. C. Powers, J. Med. Chem.,
,
= 7.56 (d, J=8.0Hz, 1H), δ =7.49 (t, J=8.0Hz, 1H) δ =2.96 (s, 3H) 13
C
NMR (100 MHz, DMSO-d6): δ =191.48, δ = 167.80, δ = 138.86, δ
6 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Please do not adjust margins
Organic & Biomolecular Chemistry
Page 7 of 7
View Article Online
DOI: 10.1039/C7OB00270J
Journal Name
ARTICLE
1996, 39, 4089. e) K. K. S. Sai, P. M. Esteves, E. T. da Penha
and D. A. Klumpp, J. Org. Chem., 2008, 73, 6506.
6946; c) S. Pan, J. Liu, H. Li, Z. Wang, X. Guo and Z. Li, Org.
Lett., 2010, 12, 1932; d) A. Clerici, C. Greco, W. Panzeri, N.
Pastori, C. Punta and O. Porta, Eur. J. Org. Chem., 2007, 24,
2
3
a) J. L. Jesuraj and J. Sivaguru, Chem. Commun., 2010, 46
,
4791; b) Z. Zhang, Q. Zhang, Z. Ni and Q. Liu, Chem.
Commun., 2010, 46, 1269; c) H. Sunden, M. Engqvist, J.
Casas, I. Ibrahem and A. Cordova, Angew. Chem., Int. Ed. 17 a) Z. Liu, J. Zhang, S. Chen and X. Wan., Angew. Chem. Int.
4050; e) E. C. McLaughlin, H. Choi, K. Wang, G. Chiou and M.
P. Doyle, J. Org. Chem., 2009, 74, 730.
2004, 43, 6532.
Ed., 2012, 51, 3231; b) G. A. DiLabio, K. U. Ingold, M. D.
Roydhouse and J. C. Walton, Org. Lett., 2004, , 4319; c) M.
a) B. E. Maryanoff, M. N. Greco, H. C. Zhang, P. Andrade-
Gordon, J. A. Kauffman, K. C. Nicolaou, A. Liu and P. H.
Brungs, J. Am. Chem. Soc., 1995, 117, 1225; b) B. Munoz, C.
6
Conte, H. Miyamura, S. Kobayashi and V. Chechik, Chem.
Commun., 2010, 46, 145.
Z. Giam and C. H. Wong, Bioorg. Med. Chem., 1994, 2, 1085– 18 a) S. C. Ghosh, J S. Y. Ngiam, C. L. L. Chai, A. M. Seayad, T. T.
1090; c)M. Bouma, G. Masson and J. Zhu, J. Org. Chem.,
2010, 75, 2748; d) J. Chen and R. F. Cunico, J. Org. Chem.
2004, 69, 5509; e) J. Bras, and L. Muzart, J. Chem. Rev., 2011,
Dang and A. Chena, Adv. Synth. Catal., 2012, 354, 1407; b)
W. J. Yoo and C. J. Li, J. Am. Chem. Soc., 2006, 128, 13064; c)
C. L. Sun, B. J. Li and Z. J. Shi, Chem. Rev., 2011, 111, 1293.
111, 1170; f) C. Liu, H. Zhang, W. Shi and A. W. Lei, Chem. 19 a)W. J. Yoo and C. J. Li, J. Am. Chem. Soc., 2006, 128, 13064;
Rev., 2011, 111, 1780; g) T. A. Ramirez, B. G. Zhao and Y. Shi,
Chem. Soc. Rev., 2012, 41, 931.
F. Ozawa and A. Yamamoto, Chem. Lett., 1982, 6, 865.
b) X. Zhang and L. Wang, Green Chem., 2012, 14, 2141.c) Q.
H. Gao, S. Liu, X. Wu, and A. X. Wu, Org. Lett., 2014, 16, 4582.
20 L. Liu, L Du, D. Z. Negrerie, Y. F. Du and K Zhao, Org. Lett.,
2014, 16, 5772.
4
5
a) F. Ozawa, H. Soyma, T. Yamamoto and A. Yamamoto,
Tetrahedron. Lett., 1982, 23, 3383; b) T. Kobayashi and M. 21 H. Y. Du, Q. Ruan, M. H. Qi and W Han, J. Org. Chem., 2015,
Tanaka, J. Organomet. Chem., 1982, 233, C64; c) B. Apanda, 80, 7816.
S. Zolezzi, G. Valdebenito, J. C.Va squez, S. A. Moya and P. 22 R. Deshidi, M. Kumar, S. Devari and B. A. Shah, Chem.
Aguirre, J. Chil. Chem. Soc., 2013, 58, 2136; d) T. Fukuyama, Commun., 2014, 50, 9533.
T. Inouye and I. Ryu, J. Organomet. Chem., 2007, 692, 685; e) 23 D. K. Li, M. Wang, J. Liu, Q. Zhao and L. Wang, Chem.
́
D. U. Nielsen, K. Neumann, R. H. Taaning, A. T. Lindhardt, A.
Modvig and T. Skrydstrup, J. Org. Chem., 2012, 77, 6155.
a) C. Zhang and N. Jiao, J. Am. Chem. Soc., 2010, 132, 28; b)
Commun., 2013, 49, 3640.
24 X. B. Zhang, M. Wang, Y. C. Zhang and L. Wang, RSC Adv.,
6
2013,
25 X. B. Zhang and L. Wang, Green Chem., 2012, 14, 2141.
10231; c) M. Kumar, S. Devari, A. Kumar, S. Sultan, Q. N. 26 Y. Kumar, M. Shaw, R. Thakur and A. Kumar, J. Org. Chem.,
3, 1311.
F. Liu, K. Liu, X. Yuan and C. Li, J. Org. Chem., 2007, 72
,
Ahmed, M. Rizvi and B. A. Shah, J. Org. Chem., 2015,
S. Dutta, S. S. Kotha and G. Sekar, Rsc Adv., 2015, , 47265.
a) D. Kumar, S. R. Vemula and G. R. Cook, ACS. Catal., 2016,
, 3531; b) M. Zhang, A. Q. Zhang and Y. Peng, J. Organomet.
Chem., 2013, 723, 224; c) G. Qiu and J. Wu, Org. Chem.
Front., 2015, , 169.
4
, 438.
2016, 81, 6617.
7
8
5
6
2
9
a) C. Zhang, X. Zong, L. Zhang and N. Jiao, Org. Lett., 2012,
14, 3280; b) S. Gowrisankar, H. Neumann and M. Beller,
Angew. Chem., Int. Ed. 2011, 50, 5139.
10 a) Y. Shao, Z. Wu, C. Miao and L. Liu, J. Organomet. Chem.,
2014, 767, 60; b) J. Xie, H Li,. J. Zhou, Y. Cheng and C. Zhu,
Angew. Chem. Int. Ed., 2012, 51, 1252; c) J. Xie, H. Li, Q. Xue,
Y. Cheng and C. Zhu, Adv. Synth. Catal., 2012, 354, 1646; d)
Y. Peng, L. Cui, G. Zhang and L. Zhang, J. Am. Chem. Soc.,
2009, 131, 5062; e) G. Zhang, Y. Peng, L. Cui and L. Zhang,
Angew. Chem. Int. Ed., 2009, 48, 3112.
11 N. Sharma, S. S. Kotha, N. Lahiri and G. Sekar, Synthesis.,
2015, 47, 726.
12 a) Q. Zhao, T. Miao, X. Zhang, W. Zhou and L. Wang, Org.
Biomol. Chem., 2013, 11, 1867; b) W. P. Mai, H. H. Wang, Z.
C .Li, J. W. Yuan, Y. M. Xiao, L. R. Yang, P. Mao and L. B Qu,
Chem. Commun., 2012, 48, 10117; c) N. Mupparapu, S. Khan,
S. Battula, M. Kushwaha, A. P. Gupta, Q. N. Ahmed, and R. A.
Vishwakarma, Org. Lett., 2014, 16, 1152; d) N. Mupparapu,
R. A. Vishwakarma and Q. N. Ahmed, Tetrahedron., 2015, 71
3417; e) S. Guo, Z. Fang, Z. Yang, C. Liu, Z. Dai, L. Zhao and K.
Guo, RSC. Adv., 2016, , 1503.
,
6
13 a) C. Zhang, X. Zong, L. Zhang and N. Jiao, Org. Lett., 2012,
14, 3280; b) Y. Shao, Z. Wu, C. Miao and L. Liu, J. Organomet.
Chem., 2014, 767, 60; c) N. Mupparapu, S. Khan, S. Battula,
M. Kushwaha, A. P. Gupta, Q. N. Ahmed and R. A.
Vishwakarma, Org. Lett., 2014, 16, 1152.
14 F.Y. Liu, K. Zhang, Y.F. Liu, S. Chen, Y.P. Chen, D.L. Zhang, C.F.
Lin and B. Wang, RSC Adv., 2017, 7, 7158.
15 Z. L. Zhang, J. H. Su, Z. G. Zha and Z. Y. Wang, Chem.
Commun., 2013, 49, 8982.
16 a) L. Gan, S. Huang, X. Zhang, A. Zhang, B. Cheng, H. Cheng,
X. Li and G. Shang, J. Am. Chem. Soc., 2002, 124, 13384; b) C.
M. Jones and M. J. Burkitt, J. Am. Chem. Soc., 2003, 125
,
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 7
Please do not adjust margins