Nickel(ii)-catalyzed tandem C(sp2)-H bond activation and annulation of arenes with gem-dibromoalkenes

Article abstract of DOI:10.1039/c8ra03278e

A nickel(ii)/silver(i)-catalyzed tandem C(sp²)-H activation and intramolecular annulation of arenes with dibromoalkenes has been successfully achieved, which offers an efficient approach to the 3-methyleneisoindolin-1-one scaffold. Attractive features of this system include its low cost, ease of operation, and its ability to access a wide range of isoindolinones.

Full text of DOI:10.1039/c8ra03278e

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Nickel(II)-catalyzed tandem C(sp2)–H bond
activation and annulation of arenes with gem-
dibromoalkenes†
Cite this: RSC Adv., 2018, 8, 28668
*
Yun Shi, Meng-Sheng Li, Fangdong Zhang and Baohua Chen
Received 17th April 2018
Accepted 25th July 2018
A nickel(II)/silver(I)-catalyzed tandem C(sp2)–H activation and intramolecular annulation of arenes with
dibromoalkenes has been successfully achieved, which offers an efficient approach to the 3-
methyleneisoindolin-1-one scaffold. Attractive features of this system include its low cost, ease of
operation, and its ability to access a wide range of isoindolinones.
DOI: 10.1039/c8ra03278e
rsc.li/rsc-advances
Over the past years, the transition-metal-catalyzed oxidative C– Ag2CO3 of previous all the reactions, thus generating stoichio-
H/C–H cross-coupling reaction has emerged as a useful, atom- metric amounts of undesired wastes.
and step-economic synthetic protocol to construct a series of
To our knowledge, the synthesis of alkynes is among the
important N-heterocycles.1 In this context, the synthesis of most fundamental and important synthetic transformations
isoindolinones has attracted considerable attention owing to due to the unique reactivity of alkynes including addition,
their interesting biological and pharmaceutical properties,2 as oxidation, reduction, and in particular cyclization.12 However,
well as their usefulness as precursors for the synthesis of the lack of reactivity of alkynes, more electron-decient than the
structurally diverse and complex molecules (Scheme 1).2c,3 corresponding alkenes, makes it harder to couple them with
Several methods have successfully been developed toward iso- heteroarenes. As a consequence, terminal alkyne precursors
indolinone synthesis based on Pd,4 Cu,5 Ru,6 and Rh7 salts. have been developed to facilitate acetylene exchange.13 Halo-
Among these reactions, the oxidative coupling reactions of genoalkynes,14
hypervalent
alkynyliodoniums,15acetylenic
benzamides with alkenes4b,6,7a,f,g or alkynes5a,5d exhibit high sulfones,16 copper acetylides17 and a,b-ynoic acids18 allowed the
atom economy and the application of this strategy to simple generation of more activated alkyne moieties thus broadening
arenes is still largely underdeveloped.8 For instance, in 2015, the applications of direct alkynylation reactions to heterocycles.
Zhang's group9 revealed cobalt-catalyzed oxidative alkynylation Among these alternatives, gem-dihaloalkenes emerged as more
and cyclization of simple arenes and terminal alkynes with efficient coupling partners than the corresponding mono-
silver-cocatalyst via 2-fold C–H bond and N–H bond cleavage halogenated alkynes along with being inexpensive and readily-
and C–C bond and C–N bond formation. In 2016, Song's group10 available.19 Indeed, the two geminal halogen atoms on the
developed a method of a cobalt(II)-catalyzed decarboxylative alkenyl carbon enhance the reactivity of metal complexes thus
C–H activation/annulation of benzamides and alkynyl carbox- facilitating cross coupling reactions.20 Stable and readily-
ylic acids and nickel(II)-catalyzed C(sp2)–H alkynylation/ available 1,1-dibromo-1-alkenes and our interests in the C–H
annulation cascade with terminal alkynes to synthesize 3- activation21 led us to consider using these reagents in the C–H
methyleneiso-indolin-1-ones. Zhang also reported a nickel- functionalization to construct the valuable isoindolinones. We
catalyzed oxidative alkynylation with amides and terminal ace- can envision that the abundance and structural diversity of the
tylenes.10c In addition, from an environmentally point of view, in
2015, wei's group11 described an operationally simple, Pd-
catalyzed C–H functionalization for the synthesis of important
and useful isoindolinones from readily available carboxamides
and carboxylic acids or anhydrides. The protocol avoided the
use of excess oxidants including benzoquinone, Cu(OAc)2, or
State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Key
Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu
Province, Lanzhou 730000, P. R. China. E-mail: chbh@lzu.edu.cn
Scheme
1 Representative isoindolinones with biological and
† Electronic supplementary information (ESI) available. See DOI:
pharmaceutical.
10.1039/c8ra03278e
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Table 1 Optimization of the reaction conditiona
aldehydes (used the preparation of gem-dibromoethylenes via
wittig reaction) as well as the merits of C–H functionalization
would make the synthetic methods desirable and attractive.
Herein, we wish to disclose the nickel(II)/silver(I)-mediated
tandem transformation involving sequential C(sp2)–H/C(sp2)–H
alkynylation and intramolecular annulation of unactivated
arenes with dibromoethylenes with the assistance of 8-amino-
quinoline (Scheme 2). These features of this approach opera-
tional simplicity, a wide-ranging substrate scope, and tolerance
of various synthetically useful functional groups.
Entry Catalyst
Solvent Oxidant Additive
Yield (%)b
1
2
3
4
5
6
7
8
NiCl$6H2O
Ni(acac)2
Ni(OTf)2
Ni(PPh3)2Cl2
Cu(OAc)2
Co(OAc)2$4H2O Xylene
Xylene
Xylene
Xylene
Xylene
Xylene
Ag2CO3
Ag2CO3
Ag2CO3
Ag2CO3
Ag2CO3
Ag2CO3
Ag2CO3
Ag2CO3
Ag2CO3
Ag2CO3
TBAI
TBAI
TBAI
TBAI
TBAI
TBAI
TBAI
TBAI
TBAI
TBAI
TBAI
TBAI
TBAI
TBAI
TBAI
54
62
52
73
42
31
0
Trace
41
68
56
11
20
0
Results and discussion
Initially, our investigation to explore the Ni(II)-catalyzed C sp2–H
activation began with the reaction of N-(quinolin-8-yl) benza-
mide (1a) and (2,2-dibromovinyl) benzene (2a) in the presence
of selected catalysts as shown in Table 1. Gratifyingly, (Z)-3-
benzylidene-2-(quinolin-8-yl) isoindolin-1-one 3a was obtained
in 54% yield when NiCl$6H2O (10 mol%) was employed in
xylene at 140 ꢀC for 12 h (Table 1, entry 1). In order to search out
an appropriate condition, we rstly screened a series of Ni(II)
salts and Ni(PPh3)2Cl2 (10 mol%) was chosen as the superior
catalyst to give the corresponding product with a yield of 69%
(entry 4). Moreover, the replacement of Ni(II) salts with Cu(OAc)2
and Co(OAc)2$4H2O gave a slightly less yield (entries 5 and 6).
These results reconrmed that Ni(PPh3)2Cl2 is the optimal
nickel catalyst source with a great advantage that other metal
catalysts cannot match. Subsequently, the solvent effect was
also evaluated and the promotional effect of the common
solvents, such as DMF, DMSO, dioxane, and MeCN decreased
drastically except chlorobenzene delivered 3a in up to 68% yield
(entries 8–11). We suppose that the enhanced reactivity with
aromatic solvent arises in part from its coordination with nickel
catalyst, which would facilitate the formation of nickel chelate,
intermediate. To further improve the conversion, we turned our
attention to the oxidant effect and here we screened a number
of silver(I) salts and another oxidant Cu(OAc)2, which showed
Ag2CO3 was the best choice which promoted the formation of
ring-closing reaction to give the desired product (entries 12–16).
Next, we investigated the remarkable effect of additives using
sodium iodide and different ammonium salts, however the
reaction even did not work except TBAB with 58% yield, which
implicated that the main role of TBAI in this transformation
may be the phase transfer catalyst (entries 17–20). And nally,
we examined the reaction under argon and oxygen atmosphere,
obtained 37% and 41% yield respectively, which indicated the
inuence of gas atmosphere for the reaction was very low
—
Xylene
DMF
DMSO
PhCl
Ni(PPh3)2Cl2
Ni(PPh3)2Cl2
Ni(PPh3)2Cl2
Ni(PPh3)2Cl2
Ni(PPh3)2Cl2
Ni(PPh3)2Cl2
Ni(PPh3)2Cl2
Ni(PPh3)2Cl2
Ni(PPh3)2Cl2
Ni(PPh3)2Cl2
Ni(PPh3)2Cl2
Ni(PPh3)2Cl2
Ni(PPh3)2Cl2
Ni(PPh3)2Cl2
Ni(PPh3)2Cl2
Ni(PPh3)2Cl2
9
10
11
12
13
14
15
16
17
18
19
20
21
22c
23d
Dioxane Ag2CO3
Xylene
Xylene
Xylene
Xylene
Xylene
Xylene
Xylene
Xylene
Xylene
Xylene
Xylene
Xylene
AgOAc
Ag2O
AgOTf
—
0
0
0
58
Cu(OAc)2 TBAI
Ag2CO3
Ag2CO3
Ag2CO3
Ag2CO3
Ag2CO3
Ag2CO3
Ag2CO3
NaI
TBAB
TBAF$4H2O
Me4NCl
—
TBAI
TBAI
0
Trace
0
64
61
a
Reaction condition: compound 1a (0.1 mmol), 2a (0.2 mmol), catalyst
(10 mol%), Na2CO3 (2 equiv.), oxidant (4 equiv.), additive (3 equiv.),
b
solvent (2.0 mL), under air, 110 ꢀC, 12 h. Estimated by 1H NMR
spectroscopy using CH2Br2 as an internal reference, Q ¼ quinolin-8-yl.
c
d
Under Ar. Under O2.
(entries 22 and 23). In addition, no reaction was observed in the
absence of the nickel catalyst or silver salt and additive, indi-
cating the necessity of both catalyst, Ag(I) salts and additives for
the reaction (entries 7, 15, 21).
Under the optimized conditions, we examined the applica-
bility of the catalytic system for different directing groups, as
shown in Scheme 3. Interestingly, N-(quinolin-8-yl) benzamide
(1a-1) could promote the alkynylation/annulation reaction
smoothly as well, delivering the corresponding isoindolinone in
73% yield, with high selectivity. Nevertheless, other common
directing groups including the monodentate group, N-methox-
ybenzamide (1a-2), N-(naphthalen-1-yl) benzamide (1a-3), the
bidentate coordinating groups, N-(pyridin-2-yl) benzamide (1a-
4) and N-(pyridin-1-oxide-2-yl) benzamide (1a-5) were incapable
of promoting the reaction. These control experiments showed
the indispensable role of the 8-aminoquinoline moiety for this
reaction.
Next, we set out to explore the scope of N-(quinolin-8-yl)
benzamide partners as summarized in Scheme 4. To our
delight, the reaction system could accelerate the tandem reac-
tion of a wide array of N-(quinolin-8-yl) benzamides with (2,2-
dibromovi-nyl)benzene, delivering a series of functionalized 3-
methyleneisoindolin-1-ones in moderate to excellent yields. The
Scheme 2 Nickel(II)/silver(I)-catalyzed alkynylation/annulation of are-
nes with dibromoalkenes.
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Scheme 3 The effect of directing groups for the alkynylation/annulation reaction under standard reaction conditions.
positions of substituent on arenes had a remarkable effect on reaction. Comparing with the gem-dibromoalkenes bearing
the transformation. While the substituent was installed on the substituents on the para-site (3ab, 58.5%; 3af, 70%), the ortho-
ortho-position of the aromatic ring, the reaction did not proceed substituted ones gave lower yields (3ac, 44%; 3ae, 54.5%).
smoothly with only 31% yield (3ba–ca, 3ga–ha), which impli- Additionally, we were pleased to notice that alkyl gem-dibro-
cated that steric hindrance has a huge effect on the trans- moalkenes were also tolerated under the catalytic system,
formation. N-(Quinolin-8-yl) benzamides bearing the delivering 3-methyleneisoindolin-1-ones in acceptable yields
synthetically valuable groups, such as F, Cl, NO2 and CF3, were (3ai, 62.5%; 3aj, 69%), respectively.
also tolerated as well in this transformation, delivering the
Very recently, the transition of metal-catalyzed tandem C–H
corresponding products (3ba–fa) in moderate yields. Notably, activation and annulation of arene with terminal alkyne has
the protocol was also compatible with heterocyclic substrates, been reported by many researchers, especially in which the
liberating 3ka in acceptable yields (63.5%).
Co(II)/Co(III) and Ni(I)/Ni(III) catalytic cycle was proved.9,22a On
Subsequently, we investigated a series of various dibro- the basis of the above results of experiments and relevant
moalkenes under the optimized conditions as displayed in literatures.22 We speculated that the reaction might also
Scheme 5. Electron-rich and electron-decient gem-dibromo proceed through a Ni(I)/Ni(III) catalytic process and the plausible
olens were all successfully engaged in this transformation reaction mechanism has been proposed in Scheme 6. The
(3ab–3ah). Dibromoalkenes bearing both electron-rich groups catalytic cycle initiates with the oxidation of Ni(II) by Ag2CO3 to
(Me, OMe and N-propyl substitutions) allowed better results give Ni(III) species, which activated the inert sp2 C–H bond of N-
furnishing alkynylation and cyclization products (3ae–3ah) (quinolin-8-yl)benzamide (1a) to generate the key intermediate
between 54 to 81% isolated yields. The steric hindrance of the II. Subsequently, the attack of the corresponding bromoalkyne
ortho-position on aromatic ring had an apparent effect on the via dehydrobromination of the dibromoalkene into interme-
diate II to oxidize addition gives the essential intermediate III,
which undergoes the reductive elimination to give the alkyny-
lated product IV and liberate the Ni(II) species. The oxidation of
Ni(II) to Ni(III) by silver salts continues the cycle. And the ortho-
alkynyl amide IV occurs rapidly intramolecular cyclization in
the presence of Ag2CO3 and TBAI to give the 3-
Scheme
condition: compound 1a (0.1 mmol), 2a (0.2 mmol), Ni(PPh3)2Cl2 Scheme 5 Scope of various dibromoalkenesa,b
4 .
Scope of N-(quinolin-8-yl) benzamidesa,b aReaction
.
aReaction condition:
(10 mol%), Na2CO3 (2 equiv.), Ag2CO3 (4 equiv.), TBAI (3 equiv.), solvent compound 1a (0.1 mmol), 2a (0.2 mmol), Ni(PPh3)2Cl2 (10 mol%),
(2.0 mL), under air, 140 ꢀC, 12 h. bIsolated yield of 3 by flash column Na2CO3 (2 equiv.), Ag2CO3 (4 equiv.), TBAI (3 equiv.), solvent (2.0 mL),
chromatography. Q ¼ quinolin-8-yl, TBAI ¼ tetrabutylammonium under air, 140 ꢀC, 12 h. bIsolated yield of 3 by flash column chroma-
iodide.
tography. Q ¼ quinolin-8-yl, TBAI ¼ tetrabutylammonium iodide.
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Scheme 6 Plausible mechanism.
methyleneisoindolin-1-one products 3aa. Additionally, the (singlet), d (doublet), t (triplet), q (quartet), m (multiplet).
possible pathway of a part of products is through the radical Coupling constants (J) are given in hertz. 13C NMR spectra were
exchange of intermediate II with alkynyl radical and subsequent recorded using a 100 MHz spectrometer. The chemical shis
reductive elimination to give the alkynylated product IV through are reported relative to residual CHCl3 (d C ¼ 77.00 ppm). High
a Ni(III)/Ni(I) mechanism.22
resolution mass spectra (HRMS) were measured with a Waters
Micromass GCT instrument, accurate masses were reported for
the molecular ion ([M]+ or [M + H]+).
Conclusions
In conclusion, we have developed an efficient, operationally
simple, and scalable nickel/silver-catalyzed unactivated C sp2–H
bond activation and cyclization for the synthesis of iso-
indolinones divergently with excellent selectivity from readily
available gem-dibromoalkenes. This protocol enables opera-
tional convenience with good tolerance of various aromatic
amides and dibromoalkenes. Furthermore, this practical
methodology may provide insight into the development of
transition metal catalyzed C–H functionalization and further
complement existing synthetic methods.
General procedure for the preparation of carboxamides
To the solution of carboxylic acid (10 mmol) and 10 drops of
DMF in 30 mL dry DCM at 0 ꢀC, oxalyl chloride (20 mmol) was
added dropwise under Ar. The mixture was then warm to r.t and
stirred for another 5 h. The solvent was removed under vacuum
to give crude acid cholid, which was used directly for next step
without further purication.
To the mixture of 8-aminoquinoline (10 mmol) and Et3N (12
mmol) in dry DCM (30 mL) at 0 ꢀC, the crude acid chloride
obtained from previous step in 20 mL dry DCM was added
dropwise. The mixture was then warm to r.t and stirred over-
night. The reaction was quenched with H2O. The mixture was
extracted, washed with saturated NaHCO3 solution. The
combined organic layers were dried (MgSO4) and concentrated
in vacuum and then puried by silica gel chromatography with
a mixture of hexanes and ethyl acetate as the eluent to afford the
corresponding amide products (reference: Chem. Commun.,
2015, 51, 7863–7866).
Experimental
General information
Unless otherwise noted, all of the reagents were purchased from
commercial suppliers and used without purication. All
product mixtures were analyzed by thin layer chromatography
glass-backed silica TLC plates with a uorescent indicator from
Branch of Qingdao Haiyang Chemical CO. LTD. UV-active
compounds were detected with a UV lamp (l ¼ 254 nm). For
ash column chromatography, silica gel (200–300 mesh) was
General procedure for the preparation of gem-dibromoalkenes
used as stationary phase. 1H NMR spectra ere recorded on To an ice cooled stirred solution of aldehyde (5.0 mmol) and
a Bruker Advance III 400 MHz spectrometer in deuterated carbon tetrabromide (2.5 g, 7.5 mmol) in anhydrous CH2Cl2 (40
chloroform. The chemical shis (d) are reported in parts per mL) was added slowly a solution of triphenylphosphine (4.0 g,
million relatives to tetramethylsilane. The multiplicities of 15.0 mmol) in dichloromethane (30 mL) by several portions.
signals are designated by the following abbreviations: s The reaction was monitored by TLC. Aer the reaction was
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complete, the mixture was diluted with hexane (100 mL) and (s, 1H), 6.69 (dt, J ¼ 8.8, 4.3 Hz, 1H), 6.54 (d, J ¼ 4.5 Hz, 4H). 13
C
puried directly by column chromatography on silica gel. If it is NMR (101 MHz, CDCl3) d 167.27, 150.53, 144.35, 140.32, 138.84,
not specied, hexane was used as an eluent for the column 135.95, 135.19, 134.00, 133.19, 130.12, 129.60, 128.98, 128.66,
chromatography (reference: RSC Adv., 2014, 4, 2322–2326).
128.21, 126.79, 126.48, 126.41, 125.78, 125.37, 121.43, 120.18,
108.69, 77.48, 77.16, 76.84. MS (ESI) m/z: 382.0 [M]+.
Typical procedure for copper(II)/silver(I)-catalyzed sequential
alkynylation and annulation of arenes with gem-
dibromoalkenes
(Z)-3-Benzylidene-5-methyl-2-(quinolin-8-yl)isoindolin-1-one
(3d)
1H NMR (400 MHz, CDCl3) d 8.84 (dd, J ¼ 4.2, 1.6 Hz, 1H), 7.96
(dd, J ¼ 8.3, 1.6 Hz, 1H), 7.87 (d, J ¼ 7.8 Hz, 1H), 7.68 (s, 1H),
7.57 (d, J ¼ 8.2 Hz, 1H), 7.47 (dd, J ¼ 7.3, 1.2 Hz, 1H), 7.37 (d, J ¼
7.2 Hz, 1H), 7.31–7.27 (m, 2H), 6.77 (s, 1H), 6.67 (t, J ¼ 6.4 Hz,
1H), 6.56–6.49 (m, 4H), 2.55 (s, 3H). 13C NMR (101 MHz, CDCl3)
d 168.33, 150.41, 144.47, 143.04, 139.14, 136.24, 135.90, 134.36,
133.73, 130.32, 130.13, 129.60, 128.92, 128.37, 128.21, 126.35,
126.01, 125.74, 123.87, 121.27, 120.07, 107.04, 77.46, 77.14,
76.83, 22.30. MS (ESI) m/z: 362.1 [M]+.
A mixture of N-(quinolin-8-yl) benzamides (1, 24.8 mg, 0.1
mmol), Ni(PPh3)2Cl2(10 mol%, 6.2 mg), Ag2CO3 (110.3 mg, 0.4
mmol), TBAI (110.8 mg, 0.3 mmol), gem-dibromoalkenes (2, 0.2
mmol) and xylene (2.0 mL) was added to a 25 mL open tube. The
ꢀ
tube was stirred at 140 C for 12 h under air. The reaction was
monitored by TLC. Aer the reaction was complete, then the
reaction mixture was cooled to room temperature, and the
reaction solution was treated with dilute p-toluenesulfonic acid
for half hour. A saturated solution of sodium bicarbonate (10.0
mL) was added to the reaction tube and the pH of the solution
in the reaction tube is neutralized to about 6–7. The mixture was
extracted with ethyl acetate (3 ꢁ 15 mL), and the organic phase
was combined and dried over Na2SO4 and was concentrated in
(Z)-3-Benzylidene-5-methoxy-2-(quinolin-8-yl) isoindolin-1-
one (3e)
vacuo. Then the mixture was subjected to column chromatog- 1H NMR (400 MHz, CDCl3) d 8.84 (dd, J ¼ 4.2, 1.7 Hz, 1H), 7.96
raphy on silica gel using petroleum ether/ethyl acetate ¼ 2 : 1 as (dd, J ¼ 8.3, 1.7 Hz, 1H), 7.89 (d, J ¼ 8.4 Hz, 1H), 7.56 (dd, J ¼ 8.2,
eluent to afford the desired products (3). And then calculated 1.3 Hz, 1H), 7.47 (dd, J ¼ 7.4, 1.4 Hz, 1H), 7.33 (d, J ¼ 2.1 Hz,
the yields.
1H), 7.30–7.26 (m, 2H), 7.09 (dd, J ¼ 8.4, 2.2 Hz, 1H), 6.74 (s,
1H), 6.67 (ddd, J ¼ 8.7, 4.7, 1.9 Hz, 1H), 6.57–6.50 (m, 4H), 3.96
(s, 3H). 13C NMR (101 MHz, CDCl3) d 168.05, 163.62, 150.40,
144.52, 141.05, 136.20, 135.91, 134.41, 133.63, 130.16, 128.95,
128.34, 128.23, 126.38, 126.09, 125.76, 125.56, 121.38, 121.27,
116.58, 107.12, 103.81, 77.48, 77.16, 76.84, 55.94. MS (ESI) m/z:
378.1 [M]+.
(Z)-3-Benzylidene-2-(quinolin-8-yl) isoindolin-1-one (3a)
1H NMR (400 MHz, CDCl3) d 8.86 (dd, J ¼ 4.2, 1.7 Hz, 1H), 7.98
(dd, J ¼ 11.2, 4.6 Hz, 2H), 7.89 (d, J ¼ 7.8 Hz, 1H), 7.69 (td, J ¼
7.6, 1.1 Hz, 1H), 7.60–7.54 (m, 2H), 7.48 (dd, J ¼ 7.3, 1.4 Hz, 1H),
7.33–7.27 (m, 2H), 6.81 (s, 1H), 6.67 (dd, J ¼ 11.1, 4.3 Hz, 1H),
6.58–6.51 (m, 4H). 13C NMR (101 MHz, CDCl3) d 168.25, 150.47,
144.47, 138.77, 136.16, 135.92, 134.26, 133.62, 132.36, 130.14,
129.19, 128.94, 128.49, 128.38, 128.22, 126.39, 126.12, 125.75,
124.03, 121.33, 119.76, 107.49, 77.50, 77.18, 76.86. MS (ESI) m/z:
348.1 [M]+.
(Z)-3-Benzylidene-6-methyl-2-(quinolin-8-yl) isoindolin-1-one
(3f)
1H NMR (400 MHz, CDCl3) d 8.84 (dd, J ¼ 4.2, 1.7 Hz, 1H), 7.96
(dd, J ¼ 8.3, 1.7 Hz, 1H), 7.79–7.78 (m, 1H), 7.76 (d, J ¼ 7.9 Hz,
1H), 7.57 (dd, J ¼ 8.2, 1.4 Hz, 1H), 7.50–7.47 (m, 1H), 7.46 (dd, J
¼ 7.4, 1.4 Hz, 1H), 7.29 (dd, J ¼ 4.4, 3.9 Hz, 1H), 7.26 (d, J ¼
8.2 Hz, 1H), 6.74 (s, 1H), 6.69–6.64 (m, 1H), 6.56–6.49 (m, 4H),
2.51 (s, 3H). 13C NMR (101 MHz, CDCl3) d 168.42, 150.45,
144.56, 139.52, 136.40, 136.30, 135.90, 134.44, 133.83, 133.44,
130.17, 128.96, 128.63, 128.41, 128.28, 126.39, 126.00, 125.76,
124.12, 121.31, 119.59, 106.74, 77.48, 77.16, 76.84, 21.72. MS
(ESI) m/z: 362.1 [M]+.
(Z)-3-Benzylidene-5-uoro-2-(quinolin-8-yl) isoindolin-1-one
(3b)
1H NMR (400 MHz, CDCl3) d 8.85 (dd, J ¼ 4.2, 1.7 Hz, 1H), 8.85
(dd, J ¼ 4.2, 1.7 Hz, 1H), 7.99–7.95 (m, 2H), 7.59 (dd, J ¼ 8.2,
1.3 Hz, 1H), 7.54 (dd, J ¼ 8.5, 2.1 Hz, 1H), 7.48 (dd, J ¼ 7.4,
1.4 Hz, 1H), 7.33–7.27 (m, 3H), 6.75 (s, 1H), 6.69 (dt, J ¼ 8.2,
4.1 Hz, 1H), 6.54 (d, J ¼ 4.9 Hz, 4H). 13C NMR (101 MHz, CDCl3)
d 167.21, 150.49, 144.32, 135.95, 135.34, 133.99, 133.14, 130.09,
128.94, 128.58, 128.16, 126.43, 126.34, 126.21, 125.75, 124.50,
121.37, 117.16, 116.92, 108.49, 106.98, 106.73, 77.44, 77.12,
76.81. MS (ESI) m/z: 366.1 [M]+.
(Z)-3-Benzylidene-5-phenyl-2-(quinolin-8-yl) isoindolin-1-one
(3g)
1H NMR (400 MHz, CDCl3) d 8.86 (dd, J ¼ 4.2, 1.7 Hz, 1H), 8.07–
8.04 (m, 2H), 7.97 (dd, J ¼ 8.3, 1.7 Hz, 1H), 7.78 (dd, J ¼ 7.9,
1.4 Hz, 1H), 7.72 (dd, J ¼ 8.1, 1.0 Hz, 2H), 7.59 (dd, J ¼ 8.2,
1.3 Hz, 1H), 7.54–7.50 (m, 3H), 7.45 (d, J ¼ 7.2 Hz, 1H), 7.33–7.29
(Z)-3-Benzylidene-5-chloro-2-(quinolin-8-yl) isoindolin-1-one
(3c)
1H NMR (400 MHz, CDCl3) d 8.84 (dd, J ¼ 4.2, 1.7 Hz, 1H), 7.97 (m, 2H), 6.88 (s, 1H), 6.71–6.65 (m, 1H), 6.58–6.51 (m, 4H). 13
C
(dd, J ¼ 8.3, 1.7 Hz, 1H), 7.92 (d, J ¼ 8.1 Hz, 1H), 7.87 (d, J ¼ NMR (101 MHz, CDCl3) d 168.10, 150.49, 145.82, 144.48, 140.81,
1.6 Hz, 1H), 7.59 (dd, J ¼ 8.2, 1.4 Hz, 1H), 7.53 (dd, J ¼ 8.1, 139.42, 136.25, 135.95, 135.12, 134.33, 133.64, 130.23, 129.14,
1.7 Hz, 1H), 7.48 (dd, J ¼ 7.4, 1.4 Hz, 1H), 7.32–7.28 (m, 2H), 6.78 129.00, 128.58, 128.51, 128.27, 127.69, 127.28, 126.43, 126.16,
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125.81, 124.47, 121.36, 118.54, 107.58, 77.48, 77.16, 76.84. MS 7.3, 1.4 Hz, 1H), 7.31–7.27 (m, 2H), 6.76 (s, 1H), 6.67 (ddd, J ¼
(ESI) m/z: 424.1 [M]+.
8.5, 7.6, 1.2 Hz, 1H), 6.30 (t, J ¼ 8.2 Hz, 2H), 5.92 (td, J ¼ 7.4,
0.7 Hz, 1H), 3.58 (s, 3H). 13C NMR (101 MHz, CDCl3) d 168.33,
156.18, 150.34, 144.60, 138.77, 136.38, 135.95, 134.10, 132.22,
130.05, 130.00, 129.00, 128.79, 128.46, 128.39, 127.93, 125.52,
123.91, 122.52, 121.11, 120.10, 118.57, 108.84, 103.92, 77.48,
77.16, 76.84, 55.03. MS (ESI) m/z: 378.1 [M]+.
(Z)-3-Benzylidene-5-nitro-2-(quinolin-8-yl) isoindolin-1-one
(3h)
1H NMR (400 MHz, CDCl3) d 8.83 (dd, J ¼ 4.2, 1.7 Hz, 1H), 8.76
(d, J ¼ 1.8 Hz, 1H), 8.42 (dd, J ¼ 8.3, 1.9 Hz, 1H), 8.15 (d, J ¼
8.3 Hz, 1H), 8.00 (dd, J ¼ 8.3, 1.7 Hz, 1H), 7.63 (dd, J ¼ 8.2,
1.3 Hz, 1H), 7.51 (dd, J ¼ 7.4, 1.4 Hz, 1H), 7.36–7.31 (m, 2H), 6.97
(s, 1H), 6.76–6.70 (m, 1H), 6.56 (d, J ¼ 4.7 Hz, 4H). 13C NMR (101
MHz, CDCl3) d 166.11, 150.86, 150.64, 144.02, 139.58, 136.09,
134.65, 133.49, 132.79, 132.59, 130.03, 129.03, 128.17, 126.81,
126.59, 125.82, 125.28, 124.09, 121.61, 115.70, 110.61, 77.48,
77.16, 76.84. MS (ESI) m/z: 393.1 [M]+.
(Z)-3-(4-Methylbenzylidene)-2-(quinolin-8-yl) isoindolin-1-one
(3n)
1H NMR (400 MHz, CDCl3) d 8.83 (dd, J ¼ 4.1, 1.5 Hz, 1H), 7.97
(t, J ¼ 7.8 Hz, 2H), 7.85 (d, J ¼ 7.8 Hz, 1H), 7.65 (t, J ¼ 7.6 Hz,
1H), 7.59–7.51 (m, 2H), 7.45 (d, J ¼ 7.4 Hz, 1H), 7.30–7.25 (m,
2H), 6.78 (s, 1H), 6.42 (d, J ¼ 7.8 Hz, 2H), 6.31 (d, J ¼ 7.8 Hz, 2H),
1.99 (s, 3H). 13C NMR (101 MHz, CDCl3) d 168.17, 150.38,
144.52, 138.81, 135.82, 135.72, 134.38, 132.25, 130.53, 130.07,
128.99, 128.91, 128.28, 128.14, 128.06, 127.00, 125.72, 123.93,
121.29, 119.67, 107.67, 77.48, 77.16, 76.84, 20.95. MS (ESI) m/z:
362.1 [M]+.
(Z)-3-(4-Chlorobenzylidene)-2-(quinolin-8-yl) isoindolin-1-one
(3i)
1H NMR (400 MHz, CDCl3) d 8.83 (dd, J ¼ 4.2, 1.7 Hz, 1H), 8.04–
7.97 (m, 2H), 7.87 (d, J ¼ 7.8 Hz, 1H), 7.69 (dd, J ¼ 13.6, 7.3 Hz,
2H), 7.58 (t, J ¼ 7.5 Hz, 1H), 7.51 (d, J ¼ 7.3 Hz, 1H), 7.38–7.30
(m, 2H), 6.71 (s, 1H), 6.50–6.43 (m, 4H). 13C NMR (101 MHz,
CDCl3) d 168.13, 150.54, 144.38, 138.52, 136.86, 136.01, 134.17,
132.49, 132.09, 131.91, 130.25, 129.43, 129.38, 129.00, 128.62,
128.39, 126.36, 125.89, 124.14, 121.54, 119.81, 105.91, 77.48,
77.16, 76.84. MS (ESI) m/z: 382.0 [M]+.
(Z)-3-(4-Propylbenzylidene)-2-(quinolin-8-yl)isoindolin-1-one
(3o)
1H NMR (400 MHz, CDCl3) d 8.83 (dd, J ¼ 4.2, 1.7 Hz, 1H), 8.00–
7.92 (m, 2H), 7.86 (d, J ¼ 7.8 Hz, 1H), 7.66 (td, J ¼ 7.6, 1.1 Hz,
1H), 7.54 (dd, J ¼ 7.8, 6.9 Hz, 2H), 7.47 (dd, J ¼ 7.4, 1.3 Hz, 1H),
7.30–7.26 (m, 2H), 6.79 (s, 1H), 6.45 (d, J ¼ 7.9 Hz, 2H), 6.32 (d, J
¼ 8.0 Hz, 2H), 2.22 (t, J ¼ 7.5 Hz, 2H), 1.42–1.32 (m, 2H), 0.80 (t, J
¼ 7.3 Hz, 3H). 13C NMR (101 MHz, CDCl3) d 168.18, 150.40,
144.54, 140.56, 138.80, 135.89, 135.81, 134.38, 132.26, 130.89,
130.11, 129.02, 128.88, 128.32, 128.08, 126.53, 125.72, 123.98,
121.25, 119.70, 107.73, 77.48, 77.16, 76.84, 37.53, 24.47, 13.80.
MS (ESI) m/z: 390.1 [M]+.
(Z)-3-(2-Chlorobenzylidene)-2-(quinolin-8-yl) isoindolin-1-one
(3j)
1H NMR (400 MHz, CDCl3) d 8.89 (dd, J ¼ 4.2, 1.6 Hz, 1H), 8.02–
7.92 (m, 3H), 7.71 (t, J ¼ 7.6 Hz, 1H), 7.62–7.54 (m, 3H), 7.34–
7.28 (m, 2H), 6.86 (d, J ¼ 8.0 Hz, 1H), 6.71 (s, 1H), 6.62 (t, J ¼
7.7 Hz, 1H), 6.35 (d, J ¼ 7.7 Hz, 1H), 6.14 (t, J ¼ 7.5 Hz, 1H). 13
C
NMR (101 MHz, CDCl3) d 168.24, 150.79, 144.49, 138.40, 137.24,
135.85, 133.82, 133.01, 132.50, 132.44, 130.49, 130.00, 129.52,
128.76, 128.62, 128.54, 127.89, 127.72, 125.77, 124.34, 124.09,
121.39, 120.13, 104.37, 77.48, 77.16, 76.84. MS (ESI) m/z: 382.0
[M]+.
(Z)-4-Benzylidene-5-(quinolin-8-yl)-4,5-dihydro-6H-thieno[2,3-
c] pyrrol-6-one (3p)
1H NMR (400 MHz, CDCl3) d 8.92 (dd, J ¼ 4.2, 1.7 Hz, 1H), 8.08
(dd, J ¼ 8.3, 1.7 Hz, 1H), 7.76 (d, J ¼ 5.2 Hz, 1H), 7.72 (dd, J ¼ 8.2,
1.3 Hz, 1H), 7.51 (dd, J ¼ 7.3, 1.4 Hz, 1H), 7.44–7.39 (m, 1H), 7.37
(dd, J ¼ 8.3, 4.2 Hz, 1H), 7.29 (d, J ¼ 5.2 Hz, 1H), 7.09 (d, J ¼
6.9 Hz, 2H), 7.04–6.99 (m, 1H), 6.94 (t, J ¼ 7.4 Hz, 2H), 6.79 (s,
1H). 13C NMR (101 MHz, CDCl3) d 159.32, 151.10, 146.16,
145.52, 144.79, 136.93, 136.37, 136.27, 134.06, 130.99, 129.48,
129.00, 128.96, 128.87, 128.12, 127.41, 125.89, 124.66, 121.68,
104.66, 77.48, 77.16, 76.84. MS (ESI) m/z: 354.0 [M]+.
(Z)-3-(2-Iodobenzylidene)-2-(quinolin-8-yl) isoindolin-1-one
(3k)
1H NMR (400 MHz, CDCl3) d 8.94 (dd, J ¼ 3.3, 0.8 Hz, 1H), 8.02–
7.97 (m, 2H), 7.95 (d, J ¼ 7.8 Hz, 1H), 7.71 (t, J ¼ 7.6 Hz, 1H), 7.60
(d, J ¼ 8.1 Hz, 1H), 7.58–7.55 (m, 1H), 7.54 (s, 1H), 7.35 (d, J ¼
6.8 Hz, 1H), 7.33–7.26 (m, 2H), 6.58 (s, 1H), 6.39–6.33 (m, 2H),
6.21 (t, J ¼ 7.5 Hz, 1H). 13C NMR (101 MHz, CDCl3) d 168.23,
150.99, 144.46, 138.38, 137.86, 137.25, 136.58, 135.93, 133.80,
132.51, 130.14, 129.87, 129.50, 128.76, 128.64, 128.48, 127.81,
125.79, 125.75, 124.12, 121.42, 120.03, 110.49, 99.83, 77.48,
77.16, 76.84. MS (ESI) m/z: 474.0 [M]+.
(Z)-3-(Cyclohexylmethylene)-2-(quinolin-8-yl) isoindolin-1-one
(3q)
1H NMR (400 MHz, CDCl3) d 8.89 (dd, J ¼ 4.2, 1.7 Hz, 1H), 8.24
(dd, J ¼ 8.3, 1.7 Hz, 1H), 8.00–7.92 (m, 2H), 7.80 (dd, J ¼ 7.3,
1.4 Hz, 1H), 7.72 (d, J ¼ 7.8 Hz, 1H), 7.69–7.64 (m, 1H), 7.60 (td, J
¼ 7.6, 1.1 Hz, 1H), 7.48 (td, J ¼ 7.5, 0.8 Hz, 1H), 7.42 (dd, J ¼ 8.3,
4.2 Hz, 1H), 5.45 (d, J ¼ 10.7 Hz, 1H), 1.72 (dt, J ¼ 14.6, 6.7 Hz,
(Z)-3-(2-Methoxybenzylidene)-2-(quinolin-8-yl) isoindolin-1-
one (3l)
1H NMR (400 MHz, CDCl3) d 8.86 (dd, J ¼ 4.2, 1.7 Hz, 1H), 7.99– 1H), 1.48–1.42 (m, 1H), 1.41–1.35 (m, 1H), 1.26 (d, J ¼ 7.0 Hz,
7.98 (m, 1H), 7.97–7.95 (m, 1H), 7.92 (d, J ¼ 7.8 Hz, 1H), 7.67 (td, 2H), 1.23–1.17 (m, 1H), 1.15–1.07 (m, 1H), 0.93–0.85 (m, 2H),
J ¼ 7.6, 1.1 Hz, 1H), 7.55 (td, J ¼ 7.9, 4.1 Hz, 2H), 7.48 (dd, J ¼ 0.74 (ddd, J ¼ 12.0, 10.8, 3.5 Hz, 2H). 13C NMR (101 MHz, CDCl3)
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d 168.48, 151.33, 145.68, 138.84, 136.21, 135.72, 134.04, 131.93,
130.67, 129.30, 129.27, 128.42, 128.39, 126.35, 123.76, 121.92,
119.40, 115.12, 77.48, 77.16, 76.84, 35.28, 33.32, 33.15, 25.69,
25.57, 25.45. MS (ESI) m/z: 353.1 [M]+.
(c) Y. Kato, M. Takemono and K. K. Achiwa, Chem. Pharm.
Bull., 1999, 47, 529–535; (d) T. R. Belliotti, W. A. Brink,
S. R. Kesten, J. R. Rubin, D. J. Wustrow, K. T. Zoski,
S. Z. Whetzel, A. E. Corbin, T. A. Pugsley, T. G. Heffner and
L. D. Wise, Bioorg. Med. Chem. Lett., 1998, 8, 1499–1502; (e)
¨
¨
T. Lubbers, P. Angehrn, H. Gmunderb and S. Herziga,
Bioorg. Med. Chem. Lett., 2007, 17, 4708–4714; (f) D. K. Luci,
E. C. Lawson, S. Ghosh, W. A. Kinney, C. E. Smith, J. Qi,
Y. Wang, L. K. Minor and B. E. Maryanoff, Tetrahedron
Lett., 2009, 50, 4958–4961; (g) M. Lamblin, A. Couture,
E. Deniau and P. Grandclaudon, Org. Biomol. Chem., 2007,
5, 1466–1471.
(Z)-3-(Cyclopropylmethylene)-2-(quinolin-8-yl) isoindolin-1-
one (3r)
1H NMR (400 MHz, CDCl3) d 8.92 (dd, J ¼ 4.2, 1.7 Hz, 1H), 8.19
(dd, J ¼ 8.3, 1.7 Hz, 1H), 7.93 (d, J ¼ 7.6 Hz, 1H), 7.90 (dd, J ¼ 8.2,
1.3 Hz, 1H), 7.85 (dd, J ¼ 7.3, 1.3 Hz, 1H), 7.66–7.62 (m, 2H), 7.57
(td, J ¼ 7.7, 0.9 Hz, 1H), 7.46 (t, J ¼ 7.7 Hz, 1H), 7.41 (dd, J ¼ 8.3,
4.2 Hz, 1H), 5.13–5.06 (m, 1H), 0.40–0.32 (m, 2H), 0.28 (dd, J ¼
9.2, 6.5 Hz, 1H), 0.11 (ddd, J ¼ 11.9, 8.6, 3.6 Hz, 1H), ꢂ0.04 (tdd,
J ¼ 8.5, 6.4, 4.5 Hz, 1H). 13C NMR (101 MHz, CDCl3) d 168.07,
151.23, 145.52, 138.15, 136.16, 135.46, 135.28, 131.89, 130.66,
129.20, 129.14, 128.16, 127.82, 126.26, 123.74, 121.82, 118.97,
113.93, 77.48, 77.16, 76.84, 8.76, 8.66. MS (ESI) m/z: 312.1 [M]+.
3 (a) V. Rys, A. Couture, E. Deniau and P. Grandclaudon,
Tetrahedron, 2003, 59, 6615–6619; (b) M. Jacolot, M. Jean,
N. Tumma, A. Bondon, S. Chandrasekhar and P. Weghe, J.
Org. Chem., 2013, 78, 7169–7175.
4 (a) K. Orito, A. Horibata, T. Nakamura, H. Ushito,
H. Nagasaki, M. Yuguchi, S. Yamashita and M. Tokuda, J.
Am. Chem. Soc., 2004, 126, 14342–14343; (b) D.-D. Li,
T.-T. Yuan and G.-W. Wang, Chem. Commun., 2011, 47,
12789–12791; (c) Q. Yu, N. Zhang, J. Huang, S. Lu, Y. Zhu,
X. Yu and K. Zhao, Chem.–Eur. J., 2013, 19, 11184–11188;
(d) N. Zhang, Q. Yu, R. Chen, J. Huang, Y. Xia and K. Zhao,
Chem. Commun., 2013, 49, 9464–9466; (e) Y. Xu, W. Hu,
X. Tang, J. Jinwu Zhao, W. Wu and H. Jiang, Chem.
Commun., 2015, 51, 6843–6846; (f) X. Kou, Y. Li, L. Wu,
X. Zhang, G. Yang and W. Zhang, Org. Lett., 2015, 17,
5566–5569.
Conflicts of interest
There are no conicts to declare.
Acknowledgements
We are grateful to the project sponsored by National Science
Foundation of P. R. China (No. 21102063) and Natural Science
Foundation of Gansu Province of China (1107RJYA080).
5 (a) J. Dong, F. Wang and J. You, Org. Lett., 2014, 16, 2884–
2887; (b) H.-L. Wang, M. Shang, S.-Z. Sun, Z.-L. Zhou,
B. N. Laforteza, H.-X. Dai and J.-Q. Yu, Org. Lett., 2015, 17,
1228–1231; (c) W. Miura, K. Hirano and M. Miura, Org.
Lett., 2015, 17, 4034–4037; (d) K. Takamatsu, K. Hirano and
M. Miura, Org. Lett., 2015, 17, 4066–4069; (e) C. Yamamoto,
K. Takamatsu, K. Hirano and M. Miura, J. Org. Chem.,
2016, 81, 7675–7684.
6 (a) R. Manoharan and M. Jeganmohan, Chem. Commun.,
2015, 51, 2929–2932; (b) X. G. Li, M. Sun, K. Liu and
P. N. Liu, Adv. Synth. Catal., 2015, 357, 395–399; (c)
M.-C. Reddy and M. Jeganmohan, Org. Lett., 2014, 16,
4866–4869.
7 (a) F. Wang, G. Song and X. Li, Org. Lett., 2010, 12, 5430–
5433; (b) C. Zhu and J. R. Falck, Chem. Commun., 2012, 48,
1674–1676; (c) T. K. Hyster, K. E. Ruhl and T. Rovis, J. Am.
Chem. Soc., 2013, 135, 5364–5367; (d) B. Zhou, W. Hou,
Y. Yang and Y. Li, Chem.–Eur. J., 2013, 19, 4701–4706; (e)
W. Hou, B. Zhou, Y. Yang, H. Feng and Y. Li, Org. Lett.,
Notes and references
1 (a) L. Ackermann, R. Vicente and A. R. Kapdi, Angew. Chem.,
Int. Ed., 2009, 48, 9792–9826; (b) P. Thansandote and
M. Lautens, Chem.–Eur. J., 2009, 15, 5874–5883; (c)
D. A. Colby, R. G. Bergman and J. A. Ellman, Chem. Rev.,
2010, 110, 624–655; (d) T. W. Lyons and M. S. Sanford,
Chem. Rev., 2010, 110, 1147–1169; (e) R. J. Jazzar, J. Hitce,
A. Renaudat, J. Sofack-Kreutzer and O. Baudoin, Chem.–
Eur. J., 2010, 16, 2654–2672; (f) T. Satoh and M. Miura,
Chem.–Eur. J., 2010, 16, 11212–11222; (g) L. McMurray,
F. O'Hara and M. J. Gaunt, Chem. Soc. Rev., 2011, 40, 1885–
1898; (h) C. S. Yeung and V. M. Dong, Chem. Rev., 2011,
111, 1215–1292; (i) C. Liu, H. Zhang, W. Shi and A. Lei,
Chem. Rev., 2011, 111, 1780–1824; (j) S. H. Cho, J. Y. Kim,
J. Kwak and S. Chang, Chem. Soc. Rev., 2011, 40, 5068–
5083; (k) J. Yamaguchi, A. D. Yamaguchi and K. Itami,
Angew. Chem., Int. Ed., 2012, 51, 8960–9009; (l) C. Zhang,
C. Tang and N. Jiao, Chem. Soc. Rev., 2012, 41, 3464–3484;
(m) G. Song, F. Wang and X. Li, Chem. Soc. Rev., 2012, 41,
3651–3678; (n) P. B. Arockiam, C. Bruneau and
P. H. Dixneuf, Chem. Rev., 2012, 112, 5879–5981; (o)
N. Kuhl, N. Schroder and F. Glorius, Adv. Synth. Catal.,
2014, 356, 1443–1460; (p) Q. Zhang, K. Chen and B.-F. Shi,
Synlett, 2014, 25, 1941–1945.
´
´
2013, 15, 1814–1817; (f) A. M. Martinez, N. Rodrıguez,
´
R. G. Arrayas and J. C. Carretero, Chem. Commun., 2014, 50,
6105–6107; (g) S. Cai, C. Chen, P. Shao and C. Xi, Org. Lett.,
2014, 16, 3142–3145; (h) M. Fujioka, T. Morimoto,
T. Tsumagari, H. Tanimoto, Y. Nishiyama and K. Kakiuchi,
J. Org. Chem., 2012, 77, 2911–2923.
8 (a) N. Matsuyama, M. Kitahara, K. Hirano, T. Satoh and
M. Miura, Org. Lett., 2010, 12, 2358; (b) T. d. Haro and
C. Nevado, J. Am. Chem. Soc., 2010, 132, 1512; (c) Y. Wei,
H. Zhao, J. Kan, W. Su and M. Hong, J. Am. Chem. Soc.,
2 (a) M. H. Norman, D. J. Minick and G. C. Rigdon, J. Med.
Chem., 1996, 39, 149–157; (b) Z.-P. Zhuang, M.-P. Kung,
M. Mu and H. F. Kung, J. Med. Chem., 1998, 41, 157–166;
28674 | RSC Adv., 2018, 8, 28668–28675
This journal is © The Royal Society of Chemistry 2018

View Article Online
Paper
RSC Advances
2010, 132, 2522; (d) S. H. Kim, S. H. Park and S. Chang, 17 C. Theunissen and G. Evano, Org. Lett., 2014, 16, 4488–4491.
Tetrahedron, 2012, 68, 5162.
9 J.-T. Zhang, H. Chen, C. Lin, Z.-X. Liu, C. Wang and
Y.-H. Zhang, J. Am. Chem. Soc., 2015, 137, 12990–12996.
18 (a) J. Kim, D. Kang, E. J. Yoo and P. H. Lee, Eur. J. Org. Chem.,
2013, 35, 7902–7906; (b) K. Park and S. Lee, RSC Adv., 2013, 3,
14165–14182.
10 (a) X.-Q. Hao, C. Du, X.-J. Zhu, P.-X. Li, J.-H. Zhang, J.-L. Niu 19 (a) P. B. Berciano, S. Lebrequier, F. Besselievre and S. Piguel,
and M.-S. Song, Org. Lett., 2016, 18, 3610–3613; (b)
X.-X. Zheng, C. Du, X.-M. Zhao, X. Zhu, J.-F. Suo,
X.-Q. Hao, J.-L. Niu and M.-P. Song, J. Org. Chem., 2016, 81,
4002–4011; (c) C. Lin, J. Zhang, Z. Chen, Y. Liu, Z. Liu and
Y. H. Zhang, Adv. Synth. Catal., 2016, 358, 1778–1793.
11 H.-W. Liang, W. Ding, K. Jiang, L. Shuai, Y. Yuan and Y. Wei,
Org. Lett., 2015, 17, 2764–2767; .
Org. Lett., 2010, 12, 4038–4041; (b) L. Ackermann,
C. Kornhaass and Y. Zhu, Org. Lett., 2012, 14, 1824–1826;
(c) G. C. Reddy, P. Balasubramanyam, N. Salvanna and
B. Das, Eur. J. Org. Chem., 2012, 471–474; (d) C. Shen,
Y. Yang, Z. Liu and Y. Zhang, Synth. Commun., 2014, 44,
1970–1977; (e) A. Srivastava, L. Aggarwal and N. Jain, ACS
Comb. Sci., 2015, 17, 39–48.
12 (a) L. Ackermann, Acc. Chem. Res., 2014, 47, 281–295; (b) 20 (a) G. Chelucci, Chem. Rev., 2012, 112, 1344–2146; (b) J. Aziz,
´
R. Chinchilla and C. Najera, Chem. Rev., 2014, 114, 1783–
1826.
T. Baladi and S. Piguel, J. Org. Chem., 2016, 81, 4122–4133; (c)
Y. Li, L. Cheng, Y. Shao, S. Jiang, J. Cai and N. Qing, Eur. J.
Org. Chem., 2015, 4325–4329; (d) W. Dai, H. Shi, X. Zhao
and S. Cao, Org. Lett., 2016, 18, 4284–4287; (e)
R. T. Thornbury and F. D. Toste, Angew. Chem., Int. Ed.,
2016, 55, 11629–11632.
13 J. P. Brand and J. Waser, Chem. Soc. Rev., 2012, 41, 4165–
4179.
14 (a) F. Besselievre and S. Piguel, Angew. Chem., Int. Ed., 2009,
48, 9553–9556; (b) N. Matsuyama, K. Hirano, T. Satoh and
M. Miura, Org. Lett., 2009, 11, 4156–4159; (c) Y. Ano, 21 (a) Z. Huang, R. Shang, Z.-R. Zhang, X.-D. Tan, X. Xiao and
M. Tobisu and N. Chatani, J. Am. Chem. Soc., 2011, 133,
12984–12986; (d) J. He, M. Wasa, K. S. L. Chan and
J.-Q. Yu, J. Am. Chem. Soc., 2013, 135, 3387–3390; (e)
E. Brachet and P. Belmont, J. Org. Chem., 2015, 80, 7519–
7529; (f) N. Sauermann, M. J. Gonzalez and L. Ackermann,
Y. Fu, J. Org. Chem., 2013, 78, 4551–4557; (b) L. Liu, Y. Lv,
Y. Wu, X. Gao, Z. Zeng, Y. Gao, G. Tang and Y. Zhao, RSC
Adv., 2014, 4, 2322–2326; (c) A.-K. Morri, Y. Thummala and
V.-R. Doddi, Org. Lett., 2015, 17, 4640–4643; (d) M. Zhao,
L. Ming, J. Tang and X. Zhao, Org. Lett., 2016, 18, 416–419.
Org. Lett., 2015, 17, 5316–5319; (g) J. Zheng, L. Huang, 22 (a) Q.-Q. Yan, Z.-K. Chen, W.-L. Yu, H. Yin, Z.-X. Liu and
Z. Li, W. Wu, J. Li and H. Jiang, Chem. Commun., 2015, 51,
5894–5897; (h) Y.-J. Liu, Y.-H. Liu, S.-Y. Yan and B.-F. Shi,
Chem. Commun., 2015, 51, 6388–6391.
Y.-H. Zhang, Org. Lett., 2015, 17, 2482–2485; (b) X.-S. Wu,
Y. Zhao and H.-B. Ge, J. Am. Chem. Soc., 2014, 136, 1789–
1792; (c) J. Yi, L. Yang, C.-G. Xia and F.-W. Li, J. Org.
Chem., 2015, 80, 6213–6221; (d) V. G. Landge, G. Jaiswal
and E. Balaraman, Org. Lett., 2016, 18, 812–815; (e)
W.-F. Song, S. Lackner and L. Ackermann, Angew. Chem.,
Int. Ed., 2014, 53, 2477–2480; (f) Y.-J. Liu, Z.-Z. Zhang,
S.-Y. Yan, Y.-H. Liu and B.-F. Shi, Chem. Commun., 2015,
51, 7899–7902; (g) B. Wang, C.-X. Lu, S.-Y. Zhang, G. He,
W. A. Nack and G. Chen., Org. Lett., 2014, 16, 6260–6263.
15 (a) J. P. Brand, J. Charpentier and J. Waser, Angew. Chem., Int.
Ed., 2009, 48, 9346–9349; (b) J. P. Brand and J. Waser, Angew.
Chem., Int. Ed., 2010, 49, 7304–7307; (c) Z.-Z. Zhang, B. Liu,
C.-Y. Wang and B.-F. Shi, Org. Lett., 2015, 17, 4094–4097;
(d) R. Boobalan, P. Gandeepan and C.-H. Cheng, Org. Lett.,
2016, 18, 3314–3317.
16 (a) J. Gong and P. L. Fuchs, J. Am. Chem. Soc., 1996, 118,
4486–4487; (b) J. S. Xiang and P. L. Fuchs, Tetrahedron
Lett., 1996, 37, 5269–5272.
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