Palladium-Catalyzed C-C Bond Activation of Cyclopropenone: Modular Access to Trisubstituted α,β-Unsaturated Esters and Amides

Article abstract of DOI:10.1021/acs.joc.0c02700

Strain-driven palladium/N-heterocyclic carbene-catalyzed C-C bond activation of diphenylcyclopropenone (DPC) has been explored for one-step access to trisubstituted α,β-unsaturated esters and amides. The designed transformation works under mild conditions providing exclusively a single stereoisomer. Mechanistic studies support the oxidative addition of the C-C bond of cyclopropenone to in-situ-generated Pd(0) intermediate. We have proved that vinylic hydrogen in the product is coming from phenol/aniline through deuterium-labeling studies. Late-stage functionalization of bioactive molecules such as procaine, estrone, and hymecromone demonstrates the robustness of this protocol.

Full text of DOI:10.1021/acs.joc.0c02700

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Article
Palladium-Catalyzed C−C Bond Activation of Cyclopropenone:
Modular Access to Trisubstituted α,β-Unsaturated Esters and
Amides
Tanmayee Nanda, Pragati Biswal, Bedadyuti Vedvyas Pati, Shyam Kumar Banjare,
and Ponneri Chandrababu Ravikumar*
Cite This: J. Org. Chem. 2021, 86, 2682−2695
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ABSTRACT: Strain-driven palladium/N-heterocyclic carbene-catalyzed C−C bond activation of diphenylcyclopropenone (DPC)
has been explored for one-step access to trisubstituted α,β-unsaturated esters and amides. The designed transformation works under
mild conditions providing exclusively a single stereoisomer. Mechanistic studies support the oxidative addition of the C−C bond of
cyclopropenone to in-situ-generated Pd(0) intermediate. We have proved that vinylic hydrogen in the product is coming from
phenol/aniline through deuterium-labeling studies. Late-stage functionalization of bioactive molecules such as procaine, estrone, and
hymecromone demonstrates the robustness of this protocol.
Rh-, Pt-, and Ni-catalyzed ring opening of cyclopropenone was
reported before,9 limited scope and lack of mechanistic evidence
offers a multitude of scopes to explore the C−C bond activation
of cyclopropenone.
INTRODUCTION
■
Transition-metal-catalyzed carbon−carbon (C−C) bond acti-
vation has attracted both organometallic chemists and organic
chemists due to its fundamental scientific importance and
potential utility in organic synthesis.1 Owing to the C−C bond’s
statistical abundance and inertness, selective activation of the
C−C bond is quite challenging and remains underdeveloped.2
Over the past few years, significant breakthroughs have been
achieved by Murakami et al.,3 Dong et al.,4 and Bower et al.5
among others,6 and these reports mainly focused on C−C bond
activation of the strained ring system due to thermodynamic
advantage in breaking strained systems. Thus, the C−C bond
activation arena driven by the ring strain of three- and four-
membered carbocycles has undergone dramatic expansion over
the years, resulting in a straightforward route to construct
complex value-added scaffolds.7 There are two primary modes of
C−C bond activation pathways: (i) oxidative addition of C−C
bonds to transition metals and (ii) β-carbon elimination.
Recently, through the β-carbon elimination pathway, we have
demonstrated C−C bond activation of cyclopropanol to achieve
1,6-diketone derivatives.8 In this vein, the smallest Huckel
aromatic system cyclopropenone is less investigated.9 Although,
α,β-Unsaturated esters and amides are common structural
motifs present in drugs and natural products. For instance, these
molecule series show antifungal, 17β-HSDCl inhibitory,
analgesic, antioxidant, anti-inflammatory, antitumor, antiviral,
and MMP-2/9 inhibitory activity.10,11 Thus, ester and amide
bond formation reactions are considered as the most significant
transformations in the pharmaceutical industry. However, only
limited methods are known to synthesize these molecules like
aldol condensation,12 Wittig reaction,13 Horner−Wadsworth−
Emmons reactions,14 and nucleophilic substitution of activated
carboxylic acid derivatives.15 Nevertheless, some starting
Received: November 12, 2020
Published: January 11, 2021
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materials are not easy to access, and sensitive functional groups
are not tolerated. Moreover, to synthesize highly substituted
conjugated esters and amides, strategies like hydroxy-carbon-
ylation,16 and amino-carbonylation17 of alkynes have been
employed. Furthermore, Rahaim and co-worker synthesized
conjugated amides by coupling of alkynes with Weinreb
amides,18a and Tsuji et al. reported the synthesis of conjugated
esters by hydroesterification of carboxylic acid derivatives18b
(Figure 1). While these new approaches have enabled the
respective α,β-unsaturated ester was observed (Table 1, entry
1). Further, to explore the steric effect of the ligand, other NHC
a
Table 1. Optimization of Reaction Conditions
b
entry
ligand
solvent
base
yield
c
1
2
3
4
5
6
7
8
L1
L2
L3
L4
L5
L4
L4
L4
L4
L4
L4
L4
L4
L4
L4
L4
1,4-dioxane
1,4-dioxane
1,4-dioxane
1,4-dioxane
1,4-dioxane
THF
benzene
cyclohexane
toluene
toluene
toluene
toluene
toluene
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Li2CO3
Na2CO3
K2CO3
NaHCO3
LiOAc
11%
c
13%
c
25%
c
30%
c
16%
c
23%
c
25%
c
38%
9
78%
37%
c
10
11
12
13
14
15
16
17
18
77%
Figure 1. (a) Titanium-promoted conjugated amide synthesis. (b)
Hydroesterification of alkynes. (c) C−C bond activation of diphenyl
cyclopropenone leading to conjugated ester and amide.
83%
c
38%
c
toluene
toluene
toluene
toluene
13%
c
NaOAc
KOAc
K2CO3
<10%
synthesis of trisubstituted conjugated esters and amides,
stereoselectivity challenges and tedious operational conditions
necessitate the development of modified methods. Thus, it is an
important objective to construct α,β-unsaturated esters and
amides directly and selectively.
c
6%
nd
nd
L4
toluene
K2CO3, without catalyst
a
Conditions: 1a (1 equiv), 2a (1 equiv), Pd(OAc)2 (10 mol %), base
(10 mol %), ligand (5 mol %), solvent (0.1 M), temperature (60 °C).
We recently illustrated the catalytic C−C bond activation of
cyclopropenone in the presence of a palladium catalyst resulting
in highly functionalized maleimide wherein cyclopropenone was
shown to behave as carbon monoxide surrogate.19 Thus, the
above successful approach and our continuous interest
encouraged us to explore an expeditious strategy to prepare
conjugated esters and amides through Pd(0)-catalyzed C−C
bond activation of diphenylcyclopropenone in the presence of
commercially available phenol and aniline moieties. In this
protocol, the NHC ligand plays a vital role in generating Pd(0)
catalyst in the presence of a catalytic amount of base. Notable
features of our strategy include (i) palladium-catalyzed C−C
bond activation of cyclopropenone, (ii) high stereoselectivity,
(iii) a wide range of functional group tolerance, (iv) short
reaction times, and (v) late-stage functionalization of bioactive
molecules and drugs like umbelliferon, estrone, and procaine.
Herein, we disclosed palladium-catalyzed ligand-controlled C−
C bond activation of cyclopropenone to give unsaturated esters
and amides in a stereoselective manner.
b
c
Isolated yields GC yield (dodecane was taken as internal standard
for GC).
ligands were screened. By increasing the sterics in the ligand, the
yield enhanced to 30% (Table 1, entries 2−4), and decreasing
the sterics further led to inferior results (Table 1, entry 5), which
implies that IPr·HCl (L4) is providing the optimal stereo-
electronics for the entitled transformation. Intrigued by this
result, we screened different nonpolar solvents. Interestingly,
after extensive screening of various solvents, it was found that
performing the reaction in toluene led to an improved yield of
α,β-unsaturated ester (Table 1, entries 6−9). Aiming to further
improve the yield, we performed the reaction with different
bases. As Cs2CO3 has a positive impact on the reaction, various
carbonates such as Li2CO3, Na2CO3, and K2CO3 (Table 1,
entries 10−12) were screened. Among them, K2CO3 enhanced
the desired product’s yield to 83% (Table 1, entry 12).
Furthermore, changing the base to bicarbonate and acetates
did not show any fruitful results (Table 1, entries 13−16).
Besides, when the reaction was performed in the absence of
ligand and catalyst, no product was obtained (Table 1, entries
17−18). This implies that the ligand and catalyst were working
synergistically for the above transformation.
RESULTS AND DISCUSSION
■
We began our investigation by examining various parameters for
reaction of the diphenylcyclopropenone 1a with phenol 2a in
the presence of Pd(OAc)2 as a catalyst. First, we screened
different N-heterocyclic carbene ligands using Cs2CO3 as a base
in 1,4-dioxane solvent, as they are known to generate Pd(0)
catalyst in situ.20
After establishing the condition, we initiated our studies to
explore the scope of the reaction. As expected, a variety of
substituted phenols could participate in the current C−C
activation reaction regardless of the electronic nature of the
substituents incorporated in the phenyl ring. A series of electron-
The screening started with less sterically hindered imidazo-
linium salts ICy·HBF4 (L1) as ligand, and an 11% yield of the
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a
Table 2. Scope of Phenols for the Synthesis of Acrylate Derivatives
a
Conditions: 1a (1 equiv), 2a (1 equiv), Pd(OAc)2 (10 mol %), K2CO3 (10 mol %), IPr·HCl (5 mol %), toluene (0.1 M), 60 °C, 2 h.
donating, aryl, and electron-withdrawing para-substituted
phenols was subjected to the reaction, which gave 67−77%
(Table 2, 3ab−3ah) yield. Further, the meta-substituted phenol
delivered the unsaturated ester in good yields (Table 2, 3ai−
3am). In this case, m-nitro-substituted phenol showed superior
reactivity, giving a 78% yield of the respective product (Table 2,
3aj). Switching the substituent position from meta to ortho did
not change the reactivity much. The compatibility of ortho tBu
and ethyl phenol suggests that the reaction is relatively robust
toward steric hindrance (Table 2, 3an−3ao). When o-Cl and o-
Br phenol were subjected to the standard conditions, 78% and
74% yields (Table 2, 3ap and 3aq) of the corresponding esters
were obtained, respectively. The tolerance of halo-substituted
phenols under palladium-catalyzed reaction conditions provides
an excellent opportunity to do various late-stage functionaliza-
tions with the products. However, o-iodophenol failed to give
the desired unsaturated ester, leading to several uncharacteriz-
able products (Table 2, 3ar). Furthermore, o-CN phenol also
provided the desired product 3as in 40% yield. The variation
concerning phenol was not limited to only monosubstituted
derivatives. To check the viability of the developed method-
ology, we chose disubstituted phenol, giving rise to a highly
substituted benzene system in the product moiety (Table 2,
3at−3aa1). In addition, 2-bromo naphthol shows good
reactivity, giving a 70% yield of the desired product (Table 2,
3aa2). Construction of a biologically important skeleton around
another bioactive molecule assumes significance. With this
thought, estrone 2a3, 4-methylumbelliferone 2a4 was chosen
(commonly known as hymecromone, which is used as a drug in
bile therapy), and the respective derivatized unsaturated ester
were synthesized in good yields (Table 2, 3aa3−3aa4). Further,
the scope of the reaction was extended to different aryl- and
alkyl-substituted cyclopropenones (Table 2, 3ba−3ha). While
various electron-rich aryl substituents in the cyclopropenone
ring gave the desired product in very good yield (Table 2, 3ba−
3da), sterically hindered substrates showed retarded reactivity,
resulting in a lower yield or even no reaction (Table 2, 3ea−
3ga). Furthermore, dialkyl-substituted cyclopropenone was also
subjected to the standard condition, giving a 64% yield of the
desired unsaturated ester 3ha.
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As the current methodology is compatible with a series of
phenol moieties, aniline was chosen as the substrate to show the
developed protocol’s diversity. As α,β-unsaturated amide is
present in several biologically active molecules, developing a
one-step protocol is essential. With this motivation, when
condition A was directly applied to the reaction of aniline 4a
with diphenyl cyclopropenone 1a, we got only a 45% yield of the
desired product 5aa. After several solvent optimizations,
delightfully, DCM was found to be working well, giving a 66%
(Table 3, 5aa) yield of the unsaturated amide. A wide variety of
substituted anilines were next evaluated under the optimized
reaction conditions, as demonstrated in Table 3. Substitution of
aniline in the para position with electron-releasing groups such
as methoxy and methyl were found to be compatible, giving 45%
and 62% yields, respectively (Table 3, 5ab and 5ac). Further,
modifiable halo substituents in the para position of aniline
worked well, giving good yields of the desired unsaturated
amides (Table 3, 5ad and 5ae). An enhanced yield was observed
in the case of electron-withdrawing groups like −CN-, −NO2-,
and −CF3-substituted aniline delivering 80−85% yields of the
desired product (Table 3, 5af−5ah). Further, reaction of meta-
substituted aniline resulted in good yields of unsaturated amides
(Table 3, 5ai−5ak).
When o-2,6-dimethyl aniline (Table 3, 5al) was taken as the
substrate, a detrimental effect on the reaction yield was
observed; otherwise, o-Me, o-Cl, and o-acetyl anilines delivered
quantitative amounts of the desired products (Table 3, 5am−
5ao). Furthermore, when 2-aminobenzothiazole and 8-amino-
quinoline were taken as the substrates, the desired unsaturated
amide was obtained in 65% and 50% yields, respectively (Table
3, 5ap and 5aq). However, ortho-substituted diisopropyl,
bromo, and iodo aniline failed to give their respective products
(Table 3, 5ar−5at), which implies that steric bulk in the
substrate might be retarding the reaction. While screening
electronically divergent anilines, procaine 4u (local anesthetic)
was also subjected to the standard reaction conditions; it was
found to be compatible, delivering a 75% yield of the desired
unsaturated amide 5au. In essence, the developed methodology
provides a rapid and modular approach to access several
bioactive compounds.
Table 3. Scope of Anilines for the Synthesis of Acrylamide
Derivatives
a
Furthermore, the scope of α,β-unsaturated amide was
expanded to different diaryl-substituted cyclopropenones,
delivering the desired product in good to moderate yield
(Table 3, 5cf−5ef). Sterically hindered diaryl cyclopropenone
failed to give any product, leaving unreacted starting materials
(Table 3, 5ff−5gf). We also screened diethyl-substituted
cyclopropenone; it gave the respective unsaturated amide 5hf
in 55% yield. The X-ray data of 3aw and 5aq unambiguously
justify the structure of demonstrated products. Moreover, the
survival of a wide range of sensitive functional groups under the
reaction conditions without interference indicates notable
innate chemoselectivity.
The scale-up experiment and synthetic transformation
reactions were carried out to explore the efficiency and practical
utility of this method. When a 1 mmol scale reaction was
conducted, α,β-unsaturated ester 3aa and amide 5af were
isolated in 75% and 61% yields, respectively (Scheme 1a). Also,
product applicability was shown in Scheme 2b, where substrate
5aa was subjected to Lewis acid-catalyzed conditions.20 In the
presence of excess AlCl3, we isolated 3-phenyl carbostyril 5aa′ as
Scheme 1. Synthetic Application
a
Conditions: 1a (1 equiv), 4a (1 equiv), Pd(OAc)2 (10 mol %),
K2CO3 (10 mol %), IPr·HCl (5 mol %), DCM (0.1 M), 60 °C.
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the rate of the reaction was found to be accelerated by electron-
deficient substrate (Scheme 2a). When o-aminophenol 4v was
subjected to optimized reaction conditions A and B, we
observed that amide formation is highly selective though
another reactive phenolic site was available. This suggests that
the reaction is highly chemoselective (Scheme 2b). For a better
understanding of this reaction, several control experiments were
conducted. When the reaction was monitored by gas
chromatography, we observed a carbon monoxide (CO) peak
in the GC (Scheme 2c). Under the standard reaction conditions,
diphenylacetylene was formed as a side product (Scheme 2d)
(confirmed through HPLC, see Supporting Information). The
fact that in the presence of metal catalyst diphenyl acetylene is
forming along with extrusion of carbon monoxide signifies the
presence of a four-membered palladacycle intermediate
(Scheme 3) in the catalytic cycle as described in our previous
Scheme 2. Mechanistic Study
Scheme 3. Proposed Catalytic Cycle
report.19 Thus, to substantiate the formation of a four-
membered palladacycle from which diphenylacetylene 1a′ and
CO is forming, the reaction was carried out without ligand where
no product was observed, but tolane 1a′ (diphenylacetylene)
was detected as the byproduct along with diphenyl urea 6aa
(Scheme 2e) (confirmed through HPLC). Also, when the
standard reaction was performed without metal catalyst there
was no reaction (Scheme 2f) (confirmed through crude NMR).
Furthermore, to get additional information about the origin of
the vinylic hydrogen in the product, we performed a deuterium
exchange experiment. The deuterated phenol 2o′ (95% D) and
aniline 4c′ (92% D) were subjected to the optimized reaction
conditions, giving 3ao′ and 5ac′ in 50% and 70% deuterium-
exchanged products, respectively (Scheme 2g). To check the
nature of the intermediate, a radical process experiment was
performed. In the presence of 1 equiv of a radical scavenger like
TEMPO and BHT, we observed decent reactivity, giving 50%
and 80% of the desired product 3aa (Scheme 2h), indicating that
the reaction was proceeding through a nonradical pathway.
On the basis of the above experiments and literature
precedence,20 a plausible catalytic cycle has been proposed
(Scheme 3). Formation of Pd(0) in the presence of
imidazolinium salt and a catalytic amount of base was well
explored.20 Taking this into account, we presumed formation of
Pd(0) intermediate I which is undergoing oxidative addition
with the C−C bond of diphenyl cyclopropenone to give
intermediate II. Intermediate II undergoes σ-bond metathesis
the product in 86% yield (Scheme 1b). In this process one
phenyl ring got eliminated, which was supported by the result
disclosed by Ramakrishnan et al.20a Next, we examined the effect
of electronics on the reaction rate. When a competition reaction
was carried out between electron-rich and -deficient substrate,
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added and stirred vigorously (750 rpm) in a preheated aluminum block
at 60 °C for 2 h. After completion of the reaction (in 2 h) as monitored
by TLC analysis, the solvent was evaporated under reduced pressure
and the residue was purified by column chromatography on silica gel
(EtOAc/hexane) to give the pure product 3.
with phenol-D, across the C−Pd bond to form intermediate IV
(supported by experiments in Scheme 2a and 2g). Then
intermediate IV undergoes reductive elimination to deliver the
desired product 3aa′, regenerating the active Pd(0) catalyst for
the next catalytic cycle.
Caution: use a mask while using IPr·HCl.
General Procedure 3 for Synthesis of Highly Substituted Acrylate
3aa in 1 mmol Scale. To a 25 mL Schlenk tube under N2 atmosphere,
diphenyl cyclopropenone 1a (1 mmol, 1 equiv) in toluene (0.1 M, 10
mL), Pd(OAc)2 (10 mol %, 0.1 equiv), IPr·HCl (5 mol %, 0.05 equiv),
K2CO3 (10 mol %, 0.1 equiv), and phenol 2a (1 mmol, 1 equiv) were
added and stirred vigorously (750 rpm) in a preheated aluminum block
at 60 °C for 2 h. After completion of the reaction (in 2 h) as monitored
by TLC analysis, the solvent was evaporated under reduced pressure
and the residue was purified by column chromatography on silica gel
(EtOAc/hexane) to give the pure product 3aa. White solid (225 mg,
75% yield). Rf: 0.7 (in 10% EtOAc/hexane).
General Procedure 4 for Synthesis of Highly Substituted
Acrylamide 5 (Condition B). To a 25 mL Schlenk tube under N2
atmosphere, diphenyl cyclopropenone 1a (0.1 mmol, 1 equiv) in DCM
(0.1 M, 1 mL), Pd(OAc)2 (10 mol %, 0.1 equiv), IPr·HCl (5 mol %,
0.05 equiv), K2CO3 (10 mol %, 0.1 equiv), and aniline 4 (0.1 mmol, 1
equiv) were added and stirred vigorously (750 rpm) in a preheated
aluminum block at 60 °C for 2 h. After completion of the reaction (in 2
h) as monitored by TLC analysis, the solvent was evaporated under
reduced pressure and the residue was purified by column chromatog-
raphy on silica gel (EtOAc/hexane) to give the pure product 5.
General Procedure 5 for Synthesis of Highly Substituted
Acrylamide 5af in 1 mmol Scale. To a 25 mL Schlenk tube under
N2 atmosphere, diphenyl cyclopropenone 1a (1 mmol, 1 equiv) in
DCM (0.1 M, 10 mL), Pd(OAc)2 (10 mol %, 0.1 equiv), IPr·HCl (5
mol %, 0.05 equiv), K2CO3 (10 mol %, 0.1 equiv), and aniline 4f (1
mmol, 1 equiv) were added and stirred vigorously (750 rpm) in a
preheated aluminum block at 60 °C for 2 h. After completion of the
reaction (in 2 h) as monitored by TLC analysis, the solvent was
evaporated under reduced pressure and the residue was purified by
column chromatography on silica gel (EtOAc/hexane) to give the pure
product 5af. White solid (200 mg, 61% yield). Rf: 0.4 (in 10% EtOAc/
hexane).
CONCLUSION
■
In summary, we established a palladium-catalyzed C−C bond
activation strategy of the smallest Huckel aromatic system for
the synthesis of α,β-unsaturated esters and amides in a highly
stereo- and chemoselective manner. The current protocol is
quite general and covers a broad range of substrates. Further, we
demonstrated this strategy’s general application for late-stage
functionalization of bioactive molecules. In addition, conversion
of the α,β-unsaturated amide into a biologically important
quinolone motif provides a unique opportunity to extend the
developed protocol.
EXPERIMENTAL SECTION
■
General Information.21 Reactions were performed using a borosil
Schlenk tube vial under N2 atmosphere. Column chromatography was
done using 100−200 and 230−400 mesh size silica gel from Acme
Chemicals. Gradient elution was performed using distilled petroleum
ether and ethyl acetate. TLC plates were detected under UV light at 254
nm. 1H NMR and 13C NMR data were recorded on Bruker AV 400 and
700 MHz spectrometers using CDCl3 as the internal standard; the
residual CHCl3 for 1H NMR (δ = 7.26 ppm) and the deuterated solvent
signal for 13C NMR (δ = 77.36 ppm) were used as the reference.21b
Multiplicity (s = single, d = doublet, t = triplet, q = quartet, m =
multiplet, dd = double doublet), integration, and coupling constants (J)
in hertz (Hz) were determined. HRMS signal analysis was performed
using a micro TOF Q-II mass spectrometer. X-ray analysis was
conducted using a Rigaku Smartlab X-ray diffractometer at SCS,
NISER. Reagents and starting materials were purchased from Sigma-
Aldrich, Alfa Aesar, TCI, Avra, Spectrochem, and other commercially
available sources and used without further purification unless otherwise
noted.
General Procedure 6 for the Competition Reaction between
Phenols. To a 25 mL Schlenk tube under N2 atmosphere, diphenyl
cyclopropenone 1a (0.1 mmol, 1 equiv) in toluene (0.1 M, 1 mL),
Pd(OAc)2 (10 mol %, 0.1 equiv), IPr·HCl (5 mol %, 0.05 equiv),
K2CO3 (10 mol %, 0.1 equiv), 4-methoxyphenol 2b (0.1 mmol, 1
equiv), and 4-hydroxybenzaldehyde 2g (0.1 mmol, 1 equiv) were added
and stirred vigorously (750 rpm) in a preheated aluminum block at 60
°C for 2 h. After completion of the reaction (in 2 h) as monitored by
TLC analysis, the solvent was evaporated under reduced pressure and
the residue was purified by column chromatography on silica gel
(EtOAc/hexane) to give 3ab in 15% yield and 3ag in 50% yield.
General Procedure 7 for Competition Reaction between Anilines.
To a 25 mL Schlenk tube under N2 atmosphere, diphenyl cyclo-
propenone 1a (0.1 mmol, 1 equiv) in DCM (0.1 M, 1 mL), Pd(OAc)2
(10 mol %, 0.1 equiv), IPr·HCl (5 mol %, 0.05 equiv), K2CO3 (10 mol
%, 0.1 equiv), 4-methylaniline 4c (0.1 mmol, 1 equiv), and 4-
aminobenzonitrile 4f (0.1 mmol, 1 equiv) were added and stirred
vigorously (750 rpm) in a preheated aluminum block at 60 °C for 2 h.
After completion of the reaction (in 2 h) as monitored by TLC analysis,
the solvent was evaporated under reduced pressure and the residue was
purified by column chromatography on silica gel (EtOAc/hexane) to
give 5ac in 20% yield and 5af in 60% yield.
General Procedure 8 for the Radical Process Experiment. To a 25
mL Schlenk tube under N2 atmosphere, diphenyl cyclopropenone 1a
(0.1 mmol, 1 equiv) in toluene (0.1 M, 1 mL), Pd(OAc)2 (10 mol %,
0.1 equiv), IPr·HCl (5 mol %, 0.05 equiv), K2CO3 (10 mol %, 0.1
equiv), phenol 2a (0.1 mmol, 1 equiv), and radical scavenger (0.1
mmol, 1 equiv) were added and purged with nitrogen more than three
times. The reaction mixture was stirred vigorously (750 rpm) in a
preheated aluminum block at 60 °C for 2 h. After completion of the
reaction (in 2 h) as monitored by TLC analysis, the solvent was
General Procedure 1 for Synthesis of Cyclopropenones (Method
A).19,22 To a suspension of tetrachlorocyclopropene (0.64 mmol, 1
equiv) and anhydrous AlCl3 (1.35 mmol, 1.05 equiv) in CH2Cl2 (0.06
M, 10 mL) was added dropwise a solution of benzene (1.28 mmol, 2
equiv) in CH2Cl2 (1.2 M, 1 mL) at −78 °C. The mixture was stirred for
2 h, warmed to room temperature, and stirred for another 2 h. After
completion of the reaction as monitored by TLC analysis, the resulting
mixture was quenched with water, diluted with CH2Cl2, and washed
with water (2 × 50 mL) and brine (2 × 50 mL). The organic layers were
dried over anhydrous Na2SO4, filtered, and concentrated under reduced
pressure to yield the crude residue as an orange oil. The crude residue
was then purified by flash column chromatography on silica gel (20%
EtOAc in hexanes) to afford diarylcyclopropenone (175 mg, 85% yield)
as a white solid.
General Procedure 1 for Synthesis of Cyclopropenones (Method
B).22 n-Butyllithium (2.2 mmol, 2.2 equiv) was added dropwise over a
period of 60 min to a stirring solution of chloroform (0.20 mL, 2.5
mmol) and alkyne (1.0 mmol, 1 equiv) in THF (20 mL, 0.05 M) under
a N2 atmosphere at −78 °C. The resulting mixture was stirred for an
additional 4 h at −78 °C before concentrated hydrochloric acid (1 mL,
1 M) was added dropwise over 10 min. The cooling bath was removed,
and the mixture was stirred for 10 min without external cooling before
water (20 mL) was added. The mixture was extracted with
dichloromethane (5 × 20 mL), and the combined organic extracts
were dried (MgSO4) and evaporated in vacuo. The products were
isolated by flash chromatography.
General Procedure 2 for Synthesis of Highly Substituted Acrylates
3 (Condition A). To a 25 mL Schlenk tube under N2 atmosphere,
diphenyl cyclopropenone 1a (0.1 mmol, 1 equiv) in toluene (0.1 M, 1
mL), Pd(OAc)2 (10 mol %, 0.1 equiv), IPr·HCl (5 mol %, 0.05 equiv),
K2CO3 (10 mol %, 0.1 equiv), and phenol 2 (0.1 mmol, 1 equiv) were
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evaporated under reduced pressure and the residue was purified by
column chromatography on silica gel (EtOAc/hexane) to give the pure
product 3aa in 50% and 80% yield in the presence of TEMPO and
BHT, respectively.
size), giving a white solid compound 3af (26 mg) in 68% yield; mp
156−158 °C; Rf = 0.8 (10% EtOAc/hexane); 1H NMR (CDCl3, 400
MHz) δ 8.02 (s, 1H), 7.49 (d, J = 8.0 Hz, 2H), 7.40−7.38 (m, 3H),
7.32−7.30 (m, 2H), 7.26−7.17 (m, 3H), 7.09 (br, J = 4.0 Hz, 2H), 7.04
(d, J = 8.0 Hz, 2H); 13C{1H} NMR (CDCl3, 100 MHz) δ 166.3, 150.5,
142.8, 135.6, 134.6, 132.7, 131.9, 131.1, 130.1, 129.9, 129.1, 128.6,
128.4, 123.7, 119.1; IR (KBr, cm−1) 3140, 1721, 1400, 1148; HRMS
(ESI) m/z [M + H]+ calcd for C21H16BrO2 379.0328; found 379.0301.
(E)-4-Formylphenyl 2,3-Diphenyl Acrylate (3ag). 3ag was prepared
according to general procedure 2. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
size), giving a white solid compound 3ag (23 mg) in 72% yield; mp
General Procedure 9 for the Synthesis of 2-Quinolone.20g To a
solution of 5aa (0.1 mmol, 1 equiv) in anhydrous chlorobenzene (260
μL, 0.5 M) was added AlCl3 (0.5 mmol, 5 equiv) portionwise at room
temperature. The reaction mixture was stirred at 90 °C for 3 h and then
at 110 °C for 1 h. After 4 h, the reaction was quenched with NaHCO3,
and then the solvent was evaporated in vacuo. The crude mixture was
purified by column chromatography on silica gel (EtOAc/hexane),
giving the pure product 5aa′ in 86% (19 mg) yield.
(E)-Phenyl 2,3-Diphenyl Acrylate (3aa).18b 3aa was prepared
according to general procedure 2. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
size), giving a white solid compound 3aa (25 mg) in 83% yield; mp
133−135 °C; Rf = 0.8 (10% EtOAc/hexane); 1H NMR (CDCl3, 400
MHz) δ 8.04 (s, 1H), 7.41−7.32 (m, 7H), 7.25−7.09 (m, 8H);
13C{1H} NMR (CDCl3, 100 MHz) δ 166.4, 151.1, 142.0, 135.5, 134.4,
131.9, 130.8, 129.8, 129.4, 129.3, 128.7, 128.3, 128.0, 125.7, 121.6; IR
(KBr, cm−1) 3129, 1723, 1400, 1151; HRMS (ESI) m/z [M + Na]+
calcd for C21H16O2Na 323.1043; found 323.1042.
1
127−130 °C; Rf = 0.3 (10% EtOAc/hexane); H NMR (CDCl3, 400
MHz) δ 9.99 (s, 1H), 8.06 (s, 1H), 7.92 (d, J = 8.0 Hz, 2H), 7.44−7.39
(m, 3H), 7.35−7.32 (m, 4H), 7.26−7.18 (m, 3H), 7.11 (d, J = 8.0 Hz,
2H); 13C{1H} NMR (CDCl3, 100 MHz) δ 191.3, 166.0, 156.2, 143.2,
135.4, 134.5, 134.2, 131.6, 131.4, 131.2, 130.1, 130.0, 129.2, 128.7,
128.5, 122.7; IR (KBr, cm−1) 3136, 1720, 1704, 1401, 1146; HRMS
(ESI) m/z [M + K]+ calcd for C22H16O3K 367.0737; found 367.0730.
(E)-4-Nitrophenyl 2,3-Diphenyl Acrylate (3ah). 3ah was prepared
according to general procedure 2. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
size), giving a white crystalline solid 3ah (23 mg) in 67% yield; mp
167−170 °C; Rf = 0.5 (10% EtOAc/hexane); 1H NMR (CDCl3, 400
MHz) δ 8.27 (s, 1H), 8.06 (s, 1H), 7.45−7.40 (m, 3H), 7.35−7.31 (m,
4H), 7.27−7.18 (m, 3H), 7.11 (d, J = 8.0 Hz, 2H); 13C{1H} NMR
(CDCl3, 100 MHz) δ 165.7, 156.2, 145.6, 143.7, 135.3, 134.3, 131.3,
130.2, 130.0, 129.2, 128.7, 128.6, 125.4, 122.8, 122.0; IR (KBr, cm−1)
3114, 1723, 1517, 1155; HRMS (ESI) m/z [M + K]+ calcd for
C21H15NO4K 384.0638; found 384.0633.
(E)-4-Methoxyphenyl 2,3-Diphenyl Acrylate (3ab).18b 3ab was
prepared according to general procedure 2. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving white solid compund 3ab (25 mg) in 77% yield; mp
130−132 °C; Rf = 0.6 (10% EtOAc/hexane); 1H NMR (CDCl3, 400
MHz) δ 7.94 (s, 1H), 7.32−7.24 (m, 5H), 7.18−7.09 (m, 3H), 7.03−
6.98 (m, 4H), 6.81 (d, J = 8.0 Hz, 2H), 3.72 (s, 3H); 13C{1H} NMR
(CDCl3, 100 MHz) δ 167.0, 157.5, 144.9, 142.1, 135.8, 134.8, 132.3,
131.1, 130.2, 129.6, 129.0, 128.6, 128.3, 122.6, 114.7, 55.9. IR (KBr,
cm−1) 3135, 1719, 1400, 1149. HRMS (ESI) m/z [M + Na]+ calcd for
C22H18O3Na 353.1148; found 353.1154.
(E)-3-Methoxyphenyl 2,3-Diphenyl Acrylate (3ai). 3ai was
prepared according to general procedure 2. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a white solid compound 3ai (24 mg) in 73% yield;
(E)-[1,1′-Biphenyl]-4-yl 2,3-Diphenyl Acrylate (3ac).18b 3ac was
prepared according to general procedure 2. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a white solid compound 3ac (28 mg) in 75% yield;
1
mp 104−106 °C; Rf = 0.6 (10% EtOAc/hexane); H NMR (CDCl3,
400 MHz) δ 8.03 (s, 1H), 7.42−7.16 (m, 9H), 7.10 (d, J = 8.0 Hz, 2H),
6.79−6.69 (m, 3H), 3.79 (s, 3H); 13C{1H} NMR (CDCl3, 100 MHz) δ
166.6, 160.7, 152.4, 142.3, 135.7, 134.7, 132.2, 131.1, 130.1, 130.0,
129.7, 129.0, 128.6, 128.3, 114.1, 112.1, 107.8, 55.7; IR (KBr, cm−1)
3141, 1725, 1489, 1075; HRMS (ESI) m/z [M + Na]+ calcd for
C22H18O3Na 353.1148; found 353.1175.
1
mp 184−185 °C; Rf = 0.8 (10% EtOAc/hexane); H NMR (CDCl3,
400 MHz) δ 8.06 (s, 1H), 7.58 (t, J = 8.0 Hz, 4H), 7.45−7.34 (m, 8H),
7.25−7.18 (m, 5H), 7.12 (d, J = 8.0 Hz, 2H); 13C{1H} NMR (CDCl3,
100 MHz) δ 166.7, 150.9, 142.4, 140.7, 139.2, 135.8, 135.2, 134.7,
132.2, 131.1, 130.2, 129.7, 129.1 (2C), 128.6, 128.4, 127.6, 127.4,
122.2; IR (KBr, cm−1) 3141, 1720, 1401, 1151; HRMS (ESI) m/z [M +
H]+ calcd for C27H21O2 377.1536; found 377.1508.
(E)-3-Nitrophenyl 2,3-Diphenyl Acrylate (3aj). 3aj was prepared
according to general procedure 2. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
size), giving a pale white solid 3aj (27 mg) in 78% yield; mp 120−122
°C; Rf = 0.5 (10% EtOAc/hexane); 1H NMR (CDCl3, 400 MHz) δ 8.11
(d, J = 8.0 Hz, 1H), 8.07 (s, 1H), 8.05 (s, 1H), 7.58−7.50 (m, 2H),
7.43−7.40 (m, 3H), 7.34−7.25 (m, 3H), 7.20 (t, J = 8.0 Hz, 2H), 7.11
(d, J = 8.0 Hz, 2H); 13C{1H} NMR (CDCl3, 100 MHz) δ 166.0, 151.7,
149.1, 143.6, 135.3, 134.4, 131.3, 130.2, 130.1 (2C), 129.2, 128.7,
128.6, 128.5, 128.4, 121.0, 117.8; IR (KBr, cm−1) 3123, 1720, 1401,
1155; HRMS (ESI) m/z [M + Na]+ calcd for C21H15NO4Na 368.0893;
found 368.0879.
(E)-3-Cyanophenyl 2,3-Diphenyl Acrylate (3ak). 3ak was prepared
according to general procedure 2. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
size), giving a white solid compound 3ak (21 mg) in 65% yield; mp
146−148 °C; Rf = 0.4 (10% EtOAc/hexane); 1H NMR (CDCl3, 400
MHz) δ 8.05 (s, 1H), 7.54−7.47 (m, 3H), 7.45−7.40 (m, 4H), 7.33−
7.31 (m, 2H), 7.26−7.25 (m, 1H), 7.20 (t, J = 8.0 Hz, 2H), 7.11 (d, J =
8.0 Hz, 2H); 13C{1H} NMR (CDCl3, 100 MHz) δ 166.0, 151.5, 143.4,
135.3, 134.4, 131.3, 131.2, 130.6, 130.1, 130.0, 129.7, 129.2, 128.7,
128.6, 127.0, 125.8, 118.2, 113.7; IR (KBr, cm−1) 3132, 2230, 1725,
1401, 1148; HRMS (ESI) m/z [M + K]+ calcd for C22H15NO2K
364.0740; found 364.0739.
(E)-4-Fluorophenyl 2,3-Diphenyl Acrylate (3ad). 3ad was prepared
according to general procedure 2. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
size), giving a white solid compound 3ad (20 mg) in 63% yield; mp
124−126 °C; Rf = 0.7 (10% EtOAc/hexane); 1H NMR (CDCl3, 400
MHz) 8.03 (s, 1H), 7.43−7.37 (m, 3H), 7.33−7.31 (m, 2H), 7.26−
7.17 (m, 3H), 7.12−7.03 (m, 6H); 13C{1H} NMR (CDCl3, 100 MHz)
166.7, 160.5 (d, JC−F = 242.0 Hz), 147.2 (d, JC−F = 3.0 Hz), 142.6,
135.7, 134.6, 132.0, 131.1, 130.1, 129.8, 129.1, 128.6, 128.4, 123.3 (d,
J
C−F = 9.0 Hz), 116.3 (d, JC−F = 24.0 Hz); 19F NMR (CDCl3, 376 MHz)
δ −117.2; IR (KBr, cm−1) 3141, 1720, 1502, 1401, 1142; HRMS (ESI)
m/z [M + H]+ calcd for C21H16FO2 319.1129; found 319.1127.
(E)-4-Chlorophenyl 2,3-Diphenyl Acrylate (3ae).18b 3ae was
prepared according to general procedure 2. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a white solid compound 3ae (25 mg) in 76% yield;
1
mp 140−142 °C; Rf = 0.7 (10% EtOAc/hexane); H NMR (CDCl3,
400 MHz) 8.02 (s, 1H), 7.43−7.30 (m, 7H), 7.26−7.17 (m, 3H),
7.10−7.08 (m, 4H); 13C{1H} NMR (CDCl3, 100 MHz) δ 166.4, 149.9,
142.7, 135.6, 134.6, 131.9, 131.4, 131.1, 130.1, 129.9, 129.7, 129.1,
128.6, 128.4, 123.3; IR (KBr, cm−1) 3141, 1721, 1486, 1149; HRMS
(ESI) m/z [M + Na]+ calcd for C21H15ClO2Na 357.0658; found
357.0650.
(E)-4-Bromophenyl 2,3-Diphenyl Acrylate (3af). 3afwas prepared
according to general procedure 2. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
(E)-3-Chlorophenyl 2,3-Diphenyl Acrylate (3al). 3al was prepared
according to general procedure 2. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
size), giving a white solid compound 3al (20 mg) in 61% yield; mp
103−105 °C; Rf = 0.7 (10% EtOAc/hexane); 1H NMR (CDCl3, 400
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MHz) δ 8.03 (s, 1H), 7.41−7.38 (m, 3H), 7.32−7.17 (m, 8H), 7.11−
7.05 (m, 3H); 13C{1H} NMR (CDCl3, 100 MHz) δ 166.3, 151.9, 142.8,
135.6, 134.9, 134.6, 131.8, 131.2, 130.3, 130.1, 129.9, 129.1, 128.6,
128.4, 126.3, 122.6, 120.4; IR (KBr, cm−1) 3140, 1723, 1401, 1148;
HRMS (ESI) m/z [M + Na]+ calcd for C21H15ClO2Na 357.0653; found
357.0638.
cm−1) 3131, 2238, 1772, 1729, 1401, 1141; HRMS (ESI) m/z [M +
Na]+ calcd for C22H15NO2Na 348.0995; found 348.0991.
(E)-2,3-Dimethylphenyl 2,3-Diphenyl Acrylate (3at). 3at was
prepared according to general procedure 2. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a white solid 3at (21 mg) in 65% yield; mp 108−110
°C; Rf = 0.7 (10% EtOAc/hexane); 1H NMR (CDCl3, 400 MHz) δ 8.04
(s, 1H), 7.43−7.34 (m, 5H), 7.24−7.17 (m, 3H), 7.12−7.08 (m, 3H),
7.02 (d, J = 8.0 Hz, 1H), 6.93 (d, J = 8.0 Hz, 1H), 2.28 (s, 3H), 2.06 (s,
3H); 13C{1H} NMR (CDCl3, 100 MHz) δ 166.6, 149.9, 142.1, 138.7,
136.0, 134.8, 132.3, 131.1, 130.1, 129.7, 129.1, 129.0, 128.6, 128.3,
127.6, 126.3, 119.7, 20.4, 12.8; IR (KBr, cm−1) 3145, 1723, 1467, 1156;
HRMS (ESI) m/z [M + Na]+ calcd for C23H20O2Na 351.1356; found
351.1351.
(E)-3-Bromophenyl 2,3-Diphenyl Acrylate (3am). 3am was
prepared according to general procedure 2. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a pale-yellow solid compound 3am (25 mg) in 67%
1
yield; mp 102−104 °C; Rf = 0.8 (10% EtOAc/hexane); H NMR
(CDCl3, 400 MHz) δ 8.02 (s, 1H), 7.41−7.30 (m, 7H), 7.26−7.17 (m,
4H), 7.12−7.09 (m, 3H); 13C{1H} NMR (CDCl3, 100 MHz) δ 166.3,
151.9, 142.8, 135.5, 134.5, 131.8, 131.2, 130.7, 130.1, 129.9, 129.2,
129.1, 128.6, 128.4, 125.4, 122.6, 120.8; IR (KBr, cm−1) 3141, 1723,
1401, 1148; HRMS (ESI) m/z [M + Na]+ calcd for C21H15BrO2Na
401.0148; found 401.0118.
(E)-3,5-Dimethylphenyl 2,3-Diphenyl Acrylate (3au). 3au was
prepared according to general procedure 2. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a white solid compound 3au (27 mg) in 82% yield;
(E)-2-(tert-Butyl)phenyl 2,3-Diphenyl Acrylate (3an). 3an was
prepared according to general procedure 2. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a colorless liquid compound 3an (25 mg) in 71%
yield; Rf = 0.7 (10% EtOAc/hexane); 1H NMR (CDCl3, 400 MHz) δ
8.06 (s, 1H), 7.43−7.33 (m, 6H), 7.26−7.07 (m, 8H), 1.20 (s, 9H);
13C{1H} NMR (CDCl3, 100 MHz) δ 166.9, 149.9, 142.5, 141.4, 135.9,
134.7, 132.7, 131.2, 130.2, 129.8, 129.1, 128.6, 128.3, 127.4, 127.1,
125.9, 124.2, 34.6, 30.2; IR (KBr, cm−1) 3053, 1731, 1421; HRMS
(ESI) m/z [M + Na]+ calcd for C25H24O2Na 379.1669; found
379.1680.
1
mp 108−110 °C; Rf = 0.8 (10% EtOAc/hexane); H NMR (CDCl3,
400 MHz) δ 8.01 (s, 1H), 7.39−7.31 (m, 5H), 7.24−7.16 (m, 3H),
7.10−7.09 (br, J = 4.0 Hz, 2H), 6.85 (s, 1H), 6.76 (s, 2H), 2.30 (s, 6H);
13C{1H} NMR (CDCl3, 100 MHz) δ 166.9, 151.3, 142.1, 139.5, 135.9,
134.8, 132.4, 131.1, 130.1, 129.6, 129.0, 128.5, 128.2, 127.7, 119.4,
21.5; IR (KBr, cm−1) 3133, 1725, 1401, 1155; HRMS (ESI) m/z [M +
Na]+ calcd for C23H20O2Na 351.1356; found 351.1344.
(E)-2,3-Dihydro-1H-inden-5-yl 2,3-Diphenyl Acrylate (3av). 3av
was prepared according to general procedure 2. The crude reaction
mixture was purified by column chromatography using silica gel (230−
400 mesh size), giving a pale-yellow solid compound 3av (27 mg) in
80% yield; mp 102−105 °C; Rf = 0.8 (10% EtOAc/hexane); 1H NMR
(CDCl3, 400 MHz) δ 8.01 (s, 1H), 7.41−7.31 (m, 5H), 7.23−7.16 (m,
4H), 7.10 (d, J = 8.0 Hz, 2H), 6.99 (s, 1H), 6.87 (dd, J = 8.0, 4.0 Hz,
1H), 2.89 (q, J = 8.0 Hz, 4H), 2.09 (pent, J = 8.0 Hz, 2H); 13C{1H}
NMR (CDCl3, 100 MHz) δ 167.1, 149.9, 145.9, 142.0, 141.9, 135.9,
134.8, 132.5, 131.1, 130.2, 129.6, 129.0, 128.5, 128.2, 125.0, 119.4,
117.9, 33.2, 32.6, 26.1; IR (KBr, cm−1) 3141, 1726, 1401, 1159; HRMS
(ESI) m/z [M + Na]+ calcd for C24H20O2Na 363.1356; found
363.1353.
(E)-Benzo[d][1,3]dioxol-5-yl 2,3-Diphenyl Acrylate (3aw). 3aw was
prepared according to general procedure 2. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a white amorphous solid compound 3aw (28 mg) in
82% yield; mp 153−155 °C; Rf = 0.5 (10% EtOAc/hexane); 1H NMR
(CDCl3, 400 MHz) δ 8.00 (s, 1H), 7.42−7.36 (m, 3H), 7.32−7.30 (m,
2H), 7.23−7.16 (m, 3H), 7.09 (d, J = 8.0 Hz, 2H), 6.77 (d, J = 8.0 Hz,
1H), 6.67 (br, 1H), 6.57 (dd, J = 8.0, 4.0 Hz, 1H), 5.97 (s, 2H);
13C{1H} NMR (CDCl3, 100 MHz) δ 167.0, 148.2, 145.7, 145.6, 142.3,
135.7, 134.7, 132.1, 131.1, 130.1, 129.7, 129.0, 128.6, 128.3, 114.2,
108.2, 104.1, 101.9; IR (KBr, cm−1) 3140, 1721, 1400, 1171; HRMS
(ESI) m/z [M + Na]+ calcd for C22H16O4Na 367.0941; found
367.0941.
(E)-4-Chloro-2-nitrophenyl 2,3-Diphenyl Acrylate (3ax). 3ax was
prepared according to general procedure 2. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving pale-yellow liquid compound 3ax (23 mg) in 60%
yield; Rf = 0.6 (10% EtOAc/hexane); 1H NMR (CDCl3, 400 MHz) δ
8.10 (d, 1H), 8.06 (s, 1H), 7.60 (dd, J = 8.0, 4.0 Hz, 1H), 7.42−7.35 (m,
5H), 7.26−7.17 (m, 4H), 7.10 (br, J = 4.0 Hz, 2H); 13C{1H} NMR
(CDCl3, 100 MHz) δ 165.7, 144.4, 143.6, 135.2, 135.0, 134.8, 134.3,
132.2, 131.4, 130.8, 130.2, 129.2, 128.7, 128.6, 126.9, 126.8, 126.1; IR
(KBr, cm−1) 3140, 1777, 1721, 1400, 1107; HRMS (ESI) m/z [M +
Na]+ calcd for C21H14ClNO4Na 402.0504; found 402.0500.
(E)-2-Ethylphenyl 2,3-Diphenyl Acrylate (3ao). 3ao was prepared
according to general procedure 2. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
size), giving a pale-yellow compound 3ao (23 mg) in 70% yield; mp
1
88−90 °C; Rf = 0.7 (10% EtOAc/hexane); H NMR (CDCl3, 400
MHz) δ 8.04 (s, 1H), 7.43−7.33 (m, 5H), 7.24−7.15 (m, 6H), 7.11 (d,
J = 8.0 Hz, 3H), 2.50 (q, J = 8.0 Hz, 2H), 1.10 (t, J = 8.0 Hz, 3H);
13C{1H} NMR (CDCl3, 100 MHz) δ 166.6, 149.5, 142.2, 136.1 (2C),
136.0, 134.7, 132.3, 131.2, 130.0, 129.7, 129.1, 128.6, 128.3, 127.0,
126.3, 122.4, 23.8, 14.6; IR (KBr, cm−1) 3143, 1724, 1487; HRMS
(ESI) m/z [M + H]+ calcd for C23H21O2 329.1536; found 329.1534.
(E)-2-Chlorophenyl 2,3-Diphenyl Acrylate (3ap). 3ap was prepared
according to general procedure 2. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
size), giving a white crystalline solid compound 3ap (26 mg) in 78%
1
yield; mp 128−130 °C; Rf = 0.7 (10% EtOAc/hexane); H NMR
(CDCl3, 400 MHz) δ 8.09 (s, 1H), 7.45−7.37 (m, 6H), 7.29−7.15 (m,
6H), 7.12 (d, J = 8.0 Hz, 2H); 13C{1H} NMR (CDCl3, 100 MHz) δ
165.8, 147.8, 143.0, 135.6, 134.6, 131.6, 131.2, 130.6, 130.2, 129.8,
129.0, 128.6, 128.4, 127.9, 127.3, 127.2, 124.1; IR (KBr, cm−1) 3140,
1724, 1476, 1150; HRMS (ESI) m/z [M + Na]+ calcd for
C21H15ClO2Na 357.0653; found 357.0654.
(E)-2-Bromophenyl 2,3-Diphenyl Acrylate (3aq). 3aq was prepared
according to general procedure 2. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
size), giving a pale-yellow solid compound 3aq (28 mg) in 74% yield;
1
mp 100−102 °C; Rf = 0.7 (10% EtOAc/hexane); H NMR (CDCl3,
400 MHz) δ 8.10 (s, 1H), 7.60 (d, J = 8.0 Hz, 1H), 7.43−7.37 (m, 5H),
7.34−7.30 (m, 1H), 7.26−7.17 (m, 4H), 7.12 (d, J = 8.0 Hz, 3H);
13C{1H} NMR (CDCl3, 100 MHz) δ 165.8, 149.0, 143.1, 135.6, 134.6,
133.6, 131.6, 131.2, 130.3, 129.9, 129.0, 128.7, 128.6, 128.4, 127.5,
124.2, 116.5; IR (KBr, cm−1) 3141, 1724, 1491, 1150; HRMS (ESI) m/
z [M + Na]+ calcd for C21H15BrO2Na 401.0148; found 401.0149.
(E)-2-Cyanophenyl 2,3-Diphenyl Acrylate (3as). 3as was prepared
according to general procedure 2. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
size), giving a colorless liquid compound 3as (13 mg) in 40% yield; Rf =
0.5 (10% EtOAc/hexane); 1H NMR (CDCl3, 400 MHz) δ 8.13 (s, 1H),
7.68 (d, J = 8 Hz, 1H), 7.63 (t, J = 8 Hz, 2H), 7.42−7.30 (m, 7H), 7.20
(t, J = 8 Hz, 2H), 7.13 (d, J = 8 Hz, 2H); 13C{1H} NMR (CDCl3, 100
MHz) δ 165.6, 153.3, 144.0, 135.2, 134.3, 134.2, 133.5, 131.4, 130.2,
130.1, 129.2, 128.6 (2C), 126.6, 126.4, 123.6, 115.6, 107.4; IR (KBr,
(E)-2-Bromo-4-methylphenyl 2,3-Diphenyl Acrylate (3ay). 3ay
was prepared according to general procedure 2. The crude reaction
mixture was purified by column chromatography using silica gel (230−
400 mesh size), giving a pale-yellow solid compound 3ay (26 mg) in
1
65% yield; mp 80−83 °C; Rf= 0.7 (10% EtOAc/hexane); H NMR
(CDCl3, 400 MHz) δ 8.09 (s, 1H), 7.42−7.37 (m, 6H), 7.25−7.16 (m,
3H), 7.11 (d, J = 8.0 Hz, 3H), 7.06 (d, J = 8.0 Hz, 1H), 2.32 (s, 3H);
13C{1H} NMR (CDCl3, 100 MHz) δ 166.0, 146.7, 142.9, 137.6, 135.6,
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134.7, 133.9, 131.7, 131.2, 130.3, 129.8, 129.3, 129.0, 128.6, 128.4,
123.6, 116.0, 20.9; IR (KBr, cm−1) 3155, 1721, 1401, 1148; HRMS
(ESI) m/z [M + Na]+ calcd for C22H17BrO2Na 415.0304; found
415.0303
129.2, 128.6, 128.5, 125.5, 118.5, 118.1, 114.8, 110.8, 19.0; IR (KBr,
cm−1) 3143, 1726, 1624, 1401, 1142; HRMS (ESI) m/z [M + H]+ calcd
for C25H19O4 383.1278; found 383.1266.
(E)-Phenyl 2,3-Bis(4-methoxyphenyl) Acrylate (3ba). 3ba was
prepared according to general procedure 2. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a pale white solid compound 3ba (31 mg) in 86%
(E)-4-Acetyl-2-methylphenyl 2,3-Diphenyl Acrylate (3az). 3az was
prepared according to general procedure 2. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a pale white solid compound 3az (23 mg) in 66%
1
yield; mp 120−121 °C; Rf = 0.5 (10% EtOAc/hexane); H NMR
1
(CDCl3, 400 MHz) δ 7.95 (s, 1H), 7.37 (t, J = 7.6 Hz, 2H), 7.25 (t, J =
4.4 Hz, 2H), 7.20 (t, J = 7.2 Hz, 1H), 7.13 (d, J = 8.4 Hz, 2H), 7.09 (d, J
= 8.8 Hz, 2H), 6.94 (d, J = 8.8 Hz, 2H), 6.72 (d, J = 9.2 Hz, 2H), 3.84 (s,
3H), 3.77 (s, 3H); 13C{1H} NMR (CDCl3, 100 MHz) δ 167.2, 160.8,
159.5, 151.6, 141.8, 132.9, 131.4, 129.6, 129.3, 128.3, 127.6, 125.9,
122.0, 114.6, 114.1, 55.5; IR (KBr, cm−1) 3129, 1716, 1401; HRMS
(ESI) m/z [M + H]+ calcd for C23H21O4 361.1434; found 361.1428.
(E)-Phenyl 2,3-Di-p-tolyl Acrylate (3ca).18b 3ca was prepared
according to general procedure 2. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
size), giving a pale brown solid compound 3ca (26 mg) in 80% yield;
mp 133−134 °C; Rf = 0.5 (5% EtOAc/hexane); 1H NMR (CDCl3, 400
MHz) δ 7.98 (s, 1H), 7.37 (t, J = 7.6 Hz, 2H), 7.22−7.19 (m, 5H), 7.13
(d, J = 8.0 Hz, 2H), 7.03−6.99 (m, 4H), 2.39 (s, 3H), 2.29 (s, 3H);
13C{1H} NMR (CDCl3, 100 MHz) δ 167.0, 151.5, 142.1, 140.0, 138.0,
132.9, 132.0, 131.1, 130.0, 129.8, 129.6, 129.3, 125.9 (2C), 122.0, 21.7
(2C); IR (KBr, cm−1) 3134, 1717, 1603, 1399; HRMS (ESI) m/z [M +
Na]+ calcd for C23H20O2Na 351.1356; found 351.1331.
yield; mp 130−131 °C; Rf = 0.2 (10% EtOAc/hexane); H NMR
(CDCl3, 400 MHz) δ 8.05 (s, 1H), 7.84−7.81 (m, 2H), 7.43−7.39 (m,
3H), 7.35−7.33 (m, 2H), 7.24−7.18 (m, 4H), 7.11 (d, J = 8.0 Hz, 2H),
2.58 (s, 3H), 2.21 (s, 3H); 13C{1H} NMR (CDCl3, 100 MHz) δ 197.6,
165.9, 153.9, 142.9, 135.7, 135.1, 134.5, 131.7, 131.6, 131.2, 131.0,
130.0 (2C), 129.2, 128.7, 128.5, 127.7, 122.4, 26.9, 16.7.; IR (KBr,
cm−1) 3133, 1719, 1685, 1401, 1152; HRMS (ESI) m/z [M + Na]+
calcd for C24H20O3Na 379.1305; found 379.1297.
(E)-2-Bromo-5-fluorophenyl 2,3-Diphenyl Acrylate (3aa1). 3aa1
was prepared according to general procedure 2. The crude reaction
mixture was purified by column chromatography using silica gel (230−
400 mesh size), giving a pale-yellow solid compound 3aa1 (30 mg) in
76% yield; mp 115−118 °C; Rf = 0.8 (10% EtOAc/hexane); 1H NMR
(CDCl3, 400 MHz) δ 8.10 (s, 1H), 7.57−7.53 (m, 1H), 7.42−7.38 (m,
5H), 7.27−7.24 (m, 1H), 7.19 (t, J = 8.0 Hz, 2H), 7.12 (d, J = 8.0 Hz,
2H), 7.00 (dd, J = 8.0, 4.0 Hz, 1H), 6.87 (td, J = 8.0 Hz, 4.0 Hz, 1H);
13C{1H} NMR (CDCl3, 100 MHz) δ 165.3, 162.2 (d, JC−F = 247.0 Hz),
149.7 (d, JC−F = 11.0 Hz), 143.6, 135.3, 134.5, 133.9 (d, JC−F = 9.0 Hz),
131.3, 131.2, 130.2, 130.0, 129.1, 128.6, 128.5, 114.8 (d, JC−F = 22.0
Hz), 112.3 (d, JC−F = 25.0 Hz), 111.1 (d, JC−F = 4.0 Hz); 19F NMR
(CDCl3, 376 MHz) δ −112.1; IR (KBr, cm−1) 3141, 1736, 1401, 1147;
HRMS (ESI) m/z [M + Na]+ calcd for C21H14BrFO2Na 419.0053;
found 419.0029.
(E)-Phenyl 2,3-Bis(4-(tert-butyl)phenyl) Acrylate (3da). 3da was
prepared according to general procedure 2. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a yellow solid compound 3da (29 mg) in 70% yield;
mp 122−123 °C; Rf = 0.6 (5% EtOAc/hexane); 1H NMR (CDCl3, 400
MHz) δ 7.98 (s, 1H), 7.42 (d, J = 8.8 Hz, 2H), 7.36 (t, J = 7.6 Hz, 3H),
7.26 (d, J = 8.4 Hz, 2H), 7.22−7.18 (m, 3H), 7.14 (d, J = 8.4 Hz, 2H),
7.05 (d, J = 8.4 Hz, 2H), 1.36 (s, 9H), 1.26 (s, 9H); 13C{1H} NMR
(CDCl3, 100 MHz) δ 167.1, 153.2, 151.6, 151.2, 142.0, 133.0, 132.0,
131.1, 129.7, 129.6, 126.0, 125.9, 125.6 (2C), 122.0, 35.1, 35.0, 31.7,
31.4; IR (KBr, cm−1) 3134, 1720, 1605, 1398, 1195; HRMS (ESI) m/z
[M + H]+ calcd for C29H33O2 413.2475; found 413.2469.
(E)-Phenyl 2,3-Di-o-tolyl Acrylate (3ea). 3ea was prepared
according to general procedure 2. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
size), giving a white solid compound 3ea (22 mg) in 66% yield; mp
132−133 °C; Rf = 0.6 (10% EtOAc/hexane); 1H NMR (CDCl3, 400
MHz) δ 8.26 (s, 1H), 7.37−7.35 (m, 2H), 7.23−7.19 (m, 3H), 7.17−
7.09 (m, 6H), 6.83 (t, J = 7.6 Hz, 1H), 6.69 (d, J = 7.6 Hz, 1H), 2.46 (s,
3H), 2.24 (s, 3H); 13C{1H} NMR (CDCl3, 100 MHz) δ 166.8, 151.5,
140.9, 138.4, 137.0, 135.4, 133.9, 132.3, 130.5 (2C), 130.4, 129.6,
129.4, 129.3, 128.4, 126.3, 126.0, 125.8, 121.9, 20.4, 20.0; IR (KBr,
cm−1) 3131, 1722, 1615, 1401, 1189; HRMS (ESI) m/z [M + Na]+
calcd for C23H20O2Na 351.1356; found 351.1343.
(E)-Phenyl 2-Ethylpent-2-enoate (3ha). 3ha was prepared accord-
ing to general procedure 2. The crude reaction mixture was purified by
column chromatography using silica gel (230−400 mesh size), giving a
colorless liquid compound 3ha (13 mg) in 64% yield; Rf = 0.8 (5%
EtOAc/hexane); 1H NMR (CDCl3, 400 MHz) δ 7.40−7.36 (m, 2H),
7.23−7.19 (m, 1H), 7.12−7.09 (m, 2H), 6.96 (t, J = 7.2 Hz, 1H), 2.42
(q, J = 7.6 Hz, 2H), 2.28 (pent, J = 7.6 Hz, 2H), 1.10 (m, 6H); 13C{1H}
NMR (CDCl3, 100 MHz) δ 166.7, 151.5, 146.1, 133.3, 129.6, 125.8,
122.1, 22.2, 20.4, 14.3, 13.7; IR (KBr, cm−1) 3146, 1728, 1643, 1401,
1197; HRMS (ESI) m/z [M + H]+ calcd for C13H17O2 205.1223; found
205.1223.
(E)-1-Bromonaphthalen-2-yl 2,3-Diphenyl Acrylate (3aa2). 3aa2
was prepared according to general procedure 2. The crude reaction
mixture was purified by column chromatography using silica gel (230−
400 mesh size), giving a white solid compound 3aa2 (30 mg) in 70%
1
yield; mp 166−168 °C; Rf = 0.7 (10% EtOAc/hexane); H NMR
(CDCl3, 400 MHz) δ 8.26 (d, J = 8.0 Hz, 1H), 8.16 (s, 1H), 7.81 (dd, J
= 8.0, 4.0 Hz, 2H), 7.59 (t, J = 8.0 Hz, 1H), 7.50 (t, J = 8.0 Hz, 1H),
7.44−7.38 (m, 5H), 7.32 (d, J = 8.0 Hz, 1H), 7.24 (d, J = 8.0 Hz, 1H),
7.19 (t, J = 8.0 Hz, 2H), 7.14 (d, J = 8.0 Hz, 2H); 13C{1H} NMR
(CDCl3, 100 MHz) δ 165.9, 147.2, 143.1, 135.6, 134.7, 133.0, 132.7,
131.7, 131.2, 130.3, 129.9, 129.1, 129.0, 128.6, 128.5 (2C), 128.0,
127.3, 126.6, 122.3, 115.4; IR (KBr, cm−1) 3142, 1719, 1401, 1151;
HRMS (ESI) m/z [M + H]+ calcd for C25H18BrO2 429.0485; found
429.0442.
(E)-(8R,13S,14S)-13-Methyl-17-oxo-7,8,9,11,12,13,14,15,16,17-
decahydro-6H-cyclopenta[a]phenanthren-3-yl 2,3-Diphenyl Acryl-
ate (3aa3). 3aa3 was prepared according to general procedure 2. The
crude reaction mixture was purified by column chromatography using
silica gel (230−400 mesh size), giving a pale white solid compound 3aa3
(35 mg) in 75% yield; mp 148−150 °C; Rf = 0.2 (10% EtOAc/hexane);
1H NMR (CDCl3, 400 MHz) δ 8.01 (s, 1H), 7.39−7.36 (m, 3H), 7.33−
7.16 (m, 6H), 7.10 (d, J = 8.0 Hz, 2H), 6.91 (dd, J = 8.0, 4.0 Hz, 1H),
6.87 (br, J = 4.0 Hz, 1H), 2.90 (t, J = 4.0 Hz, 2H), 2.50 (dd, J = 8.0, 4.0
Hz, 1H), 2.39 (s, 1H), 2.17−1.94 (m, 5H), 1.66−1.62 (m, 1H), 1.59−
1.45 (m, 7 H), 0.91 (s, 3H); 13C{1H} NMR (CDCl3, 100 MHz) δ
170.1, 166.9, 149.3, 142.1, 138.2, 137.5, 135.8, 134.8, 132.3, 131.1,
130.2, 129.6, 129.0, 128.6, 128.3, 126.6, 121.8, 119.0, 50.7, 48.2, 44.4,
38.3, 36.1, 31.8, 29.7, 26.6, 26.1, 21.9, 14.1; IR (KBr, cm−1) 3139, 1724,
1633, 1401, 1160; HRMS (ESI) m/z [M + H]+ calcd for C33H33O3
477.2424; found 477.2419.
(E)-4-Methyl-2-oxo-2H-chromen-7-yl 2,3-Diphenyl Acrylate
(3aa4). 3aa4 was prepared according to general procedure 2. The
crude reaction mixture was purified by column chromatography using
silica gel (230−400 mesh size), giving a white solid compound 3aa4 (31
mg) in 82% yield; mp 200−203 °C; Rf = 0.3 (10% EtOAc/hexane); 1H
NMR (CDCl3, 400 MHz) δ 8.06 (s, 1H), 7.60 (d, J = 8.0 Hz, 1H),
7.44−7.39 (m, 3H), 7.35−7.32 (m, 2H), 7.28−7.10 (m, 7H), 6.26 (s,
1H), 2.43 (s, 3H); 13C{1H} NMR (CDCl3, 100 MHz) δ 166.0, 160.8,
154.5, 153.9, 152.2, 143.3, 135.4, 134.4, 131.5, 131.2, 130.1, 130.0,
(E)-N-2,3-Triphenylacrylamide (5aa).23a 5aa was prepared accord-
ing to general procedure 4. The crude reaction mixture was purified by
column chromatography using silica gel (230−400 mesh size), giving a
yellow solid compound 5aa (20 mg) in 66% yield; mp 143−145 °C; Rf
= 0.5 (10% EtOAc/hexane); 1H NMR (CDCl3, 400 MHz) δ 7.94 (s,
1H), 7.52−7.47 (m, 3H), 7.42 (d, J = 8.0 Hz, 2H), 7.36 (dd, J = 8.0, 1.6
Hz, 2H), 7.28−7.24 (m, 2H), 7.17−7.11 (m, 4H), 7.05 (t, J = 8.0 Hz,
1H), 7.01 (d, J = 8.0 Hz, 2H); 13C{1H} NMR (CDCl3, 100 MHz) δ
165.3, 138.6, 138.1, 136.1, 135.1, 134.9, 130.8, 130.4, 130.2, 129.2
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(2C), 129.1, 128.5, 124.7, 120.2; IR (KBr, cm−1) 3406, 1677, 1597,
1264.
(ESI) m/z [M + Na]+ calcd for C21H16N2O3Na 367.1053; found
367.1054.
(E)-N-(4-Methoxyphenyl)-2, 3-diphenylacrylamide (5ab).23c 5ab
was prepared according to general procedure 4. The crude reaction
mixture was purified by column chromatography using silica gel (230−
400 mesh size), giving a pale-yellow solid compound 5ab (14 mg) in
45% yield; mp 136−138 °C; Rf = 0.7 (20% EtOAc/hexane); 1H NMR
(CDCl3, 400 MHz) δ 7.96 (s, 1H), 7.51−7.49 (m, 3H), 7.37−7.34 (m,
4H), 7.19−7.13 (m, 3H), 7.11 (br, 1H), 7.02 (d, J = 8.0 Hz, 2H), 6.83
(d, J = 8.0 Hz, 2H), 3.78 (s, 3H); 13C{1H} NMR (CDCl3, 100 MHz) δ
165.2, 156.8, 138.2, 136.2, 135.2, 134.9, 131.3, 130.7, 130.3, 130.2,
129.2, 129.0, 128.5, 122.0, 114.4, 55.8; IR (KBr, cm−1) 3134, 1670,
1401; HRMS (ESI) m/z [M + Na]+ calcd for C22H19NO2Na 352.1308;
found 352.1322.
(E)-2,3-Diphenyl-N-(4-(trifluoromethyl)phenyl)acrylamide
(5ah).23c 5ah was prepared according to general procedure 4 with a
modified temperature of 80 °C. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
size), giving a colorless liquid compound 5ah (31 mg) in 85% yield; Rf =
0.6 (20% EtOAc/hexane); 1H NMR (CDCl3, 400 MHz) δ 7.99 (s, 1H),
7.59−7.51 (m, 7H), 7.37−7.35 (m, 2H), 7.33 (br, 1H), 7.22−7.15 (m,
3H), 7.03 (d, J = 8.0 Hz, 2H); 13C{1H} NMR (CDCl3, 100 MHz) δ
165.5, 141.2, 139.4, 135.8, 134.8, 134.3, 130.9, 130.4, 130.3, 129.5,
129.4, 128.6, 126.5 (q, JC−F = 4.0 Hz), 126.3, 124.4 (q, JC−F = 269.0
Hz), 119.7; 19F NMR (CDCl3, 376 MHz) δ −62.1; IR (KBr, cm−1)
3131, 1642, 1401; HRMS (ESI) m/z [M + Na]+ calcd for
C22H16F3NONa 390.1076; found 390.1080.
(E)-2,3-Diphenyl-N-(p-tolyl)acrylamide (5ac).23d 5ac was prepared
according to general procedure 4. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
size), giving a pale-yellow liquid compound 5ac (20 mg) in 62% yield;
Rf = 0.4 (10% EtOAc/hexane); 1H NMR (CDCl3, 400 MHz) δ 7.96 (s,
1H), 7.53−7.48 (m, 3H), 7.36−7.32 (m, 4H), 7.20−7.13 (m, 4H), 7.09
(d, J = 8.0 Hz, 2H), 7.02 (d, J = 8.0 Hz, 2H), 2.30 (s, 3H); 13C{1H}
NMR (CDCl3, 100 MHz) δ 165.2, 138.4, 136.2, 135.6, 135.2, 135.0,
134.4, 130.8, 130.3, 130.2, 129.7, 129.2, 129.1, 128.5, 120.2, 21.2; IR
(KBr, cm−1) 3131, 1667, 1401; HRMS (ESI) m/z [M + H]+ calcd for
C22H20NO 314.1539; found 314.1526.
(E)-2,3-Diphenyl-N-(3-(trifluoromethyl)phenyl)acrylamide (5ai).
5ai was prepared according to general procedure 4 with a modified
temperature of 80 °C. The crude reaction mixture was purified by
column chromatography using silica gel (230−400 mesh size), giving a
colorless liquid compound 5ai (22 mg) in 60% yield; Rf = 0.6 (10%
EtOAc/hexane); 1H NMR (CDCl3, 400 MHz) δ 7.99 (s, 1H), 7.74 (s,
1H), 7.65 (d, J = 8.0 Hz, 1H), 7.54−7.53 (m, 3H), 7.42−7.33 (m, 4H),
7.30 (br, 1H), 7.22−7.15 (m, 3H), 7.03 (d, J = 8.0 Hz, 2H); 13C{1H}
NMR (CDCl3, 100 MHz) δ 165.5, 139.3, 138.6, 135.8, 134.9, 134.3,
131.5, 130.9, 130.4, 130.3, 130.1 (q, JC−F = 231.0 Hz), 129.8, 129.5,
129.4, 128.6, 123.3, 121.2 (q, JC−F = 4.0 Hz), 116.9 (q, JC−F = 4.0 Hz);
19F NMR (CDCl3, 376 MHz) δ −62.7; IR (KBr, cm−1) 3140, 1666,
(E)-N-(4-Fluorophenyl)-2,3-diphenylacrylamide (5ad). 5ad was
prepared according to general procedure 4. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a white solid compound 5ad (19 mg) in 60% yield;
1400; HRMS (ESI) m/z [M + Na]+ calcd for C22H16F3NONa
390.1076; found 390.1067.
1
(E)-N-(3-Nitrophenyl)-2,3-diphenylacrylamide (5aj). 5aj was pre-
pared according to general procedure 4 with a modified temperature of
80 °C. The crude reaction mixture was purified by column
chromatography using silica gel (230−400 mesh size), giving a yellow
solid compound 5aj (26 mg) in 76% yield; mp 136−138 °C; Rf = 0.5
mp 182−183 °C; Rf = 0.5 (10% EtOAc/hexane); H NMR (CDCl3,
400 MHz) δ 7.97 (s, 1H), 7.52−7.49 (m, 3H), 7.43−7.39 (m, 2H),
7.36−7.34 (m, 2H), 7.20−7.13 (m, 4H), 7.03−6.96 (m, 4H); 13C{1H}
NMR (CDCl3, 100 MHz) δ 165.3, 159.7 (d, JC−F = 243.0 Hz), 138.7,
136.0, 135.0, 134.6, 134.2, 134.1, 130.8, 130.3 (2C), 129.2 (d, JC−F
=
F
1
11.0 Hz), 128.5, 122.0 (d, JC−F = 7.0 Hz), 115.9 (d, JC−F = 22.0 Hz); 19
(20% EtOAc/hexane); H NMR (CDCl3, 400 MHz) δ 8.24 (s, 1H),
NMR (CDCl3, 376 MHz) δ −117.7; IR (KBr, cm−1) 3140, 1643, 1403;
HRMS (ESI) m/z [M + Na]+ calcd for C21H16FNONa 340.1108;
found 340.1123.
8.01 (s, 1H), 7.93 (d, J = 8.0 Hz, 2H), 7.57−7.54 (m, 3H), 7.49−7.44
(m, 1H), 7.38−7.36 (m, 3H), 7.23−7.15 (m, 3H), 7.03 (d, J = 8.0 Hz,
2H); 13C{1H} NMR (CDCl3, 100 MHz) δ 165.6, 148.8, 139.8, 139.3,
135.5, 134.7, 134.0, 130.9, 130.5, 130.2, 130.1, 129.6, 129.5, 128.6,
125.9, 119.3, 114.9; IR (KBr, cm−1) 3139, 1670, 1401; HRMS (ESI) m/
z [M + H]+ calcd for C21H17N2O3 345.1234; found 345.1220.
(E)-N-(3-Chlorophenyl)-2,3-diphenylacrylamide (5ak). 5ak was
prepared according to general procedure 4 with a modified temperature
of 80 °C. The crude reaction mixture was purified by column
chromatography using silica gel (230−400 mesh size), giving a yellow
liquid compound 5ak (17 mg) in 51% yield; Rf = 0.8 (10% EtOAc/
hexane); 1H NMR (CDCl3, 400 MHz) δ 7.97 (s, 1H), 7.55−7.50 (m,
4H), 7.35−7.30 (m, 3H), 7.22−7.14 (m, 5H), 7.07−7.01 (m, 3H);
13C{1H} NMR (CDCl3, 100 MHz) δ 165.3, 139.3, 139.1, 135.8, 134.9
(2C), 134.4, 130.8, 130.3 (2C), 130.2, 129.4, 129.3, 128.6, 124.7, 120.2,
118.1; IR (KBr, cm−1) 3123, 1665, 1401; HRMS (ESI) m/z [M + Na]+
calcd for C21H16ClNONa 356.0813; found 356.0799.
(E)-N-(4-Chlorophenyl)-2,3-diphenylacrylamide (5ae). 5ae was
prepared according to general procedure 4. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a yellow solid compound 5ae (22 mg) in 67% yield;
1
mp 145−147 °C; Rf = 0.6 (10% EtOAc/hexane); H NMR (CDCl3,
400 MHz) δ 7.97 (s, 1H), 7.53−7.51 (m, 3H), 7.43−7.40 (m, 2H),
7.36−7.34 (m, 2H), 7.27−7.24 (m, 2H), 7.19−7.16 (m, 4H), 7.04−
7.01 (m, 2H); 13C{1H} NMR (CDCl3, 100 MHz) δ 165.3, 138.9, 136.7,
135.9, 135.0, 134.5, 130.8, 130.3 (2C), 129.7, 129.4, 129.3, 129.2,
128.6, 121.4; IR (KBr, cm−1) 3122, 1649, 1397; HRMS (ESI) m/z [M
+ H]+ calcd for C21H17ClNO 334.0993; found 334.0998.
(E)-N-(4-Cyanophenyl)-2,3-diphenylacrylamide (5af). 5af was
prepared according to general procedure 4. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a white solid compound 5af (26 mg) in 80% yield;
(E)-N-(2, 6-Dimethylphenyl)-2,3-diphenylacrylamide (5al). 5al
was prepared according to general procedure 4 with a modified
temperature 80 °C. The crude reaction mixture was purified by column
chromatography using silica gel (230−400 mesh size), giving a colorless
liquid compound 5al (15 mg) in 46% yield; Rf = 0.5 (10% EtOAc/
hexane); 1H NMR (CDCl3, 400 MHz) δ 7.96 (s, 1H), 7.53−7.46 (m,
3H), 7.43−7.41 (m, 2H), 7.20−7.13 (m, 3H), 7.09−7.05 (m, 5H), 6.70
(br, 1H), 2.18 (s, 6H); 13C{1H} NMR (CDCl3, 100 MHz) δ 165.6,
138.1, 136.9, 135.5, 135.1, 134.4 (2C), 130.8, 130.2, 130.1, 129.1 (2C),
128.5, 128.4, 127.6, 18.8; IR (KBr, cm−1) 3131, 1670, 1401; HRMS
(ESI) m/z [M + H]+ calcd for C23H22NO 328.1696; found 328.1681.
(E)-2,3-Diphenyl-N-(o-tolyl)acrylamide (5am).23e 5am was pre-
pared according to general procedure 4. The crude reaction mixture was
purified by column chromatography using silica gel (230−400 mesh
size), giving a yellow solid compound 5am (21 mg) in 67% yield; mp
1
mp 175−177 °C; Rf = 0.5 (20% EtOAc/hexane); H NMR (CDCl3,
400 MHz) δ 7.99 (s, 1H), 7.58−0.53 (m, 7H), 7.36−7.34 (m, 3H),
7.23−7.15 (m, 3H), 7.03 (d, J = 8.0 Hz, 2H); 13C{1H}NMR (CDCl3,
100 MHz) δ 165.5, 142.1, 139.9, 135.6, 134.7, 134.0, 133.5, 130.9,
130.5, 130.2, 129.6 (2C), 128.6, 119.9, 119.1, 107.5; IR (KBr, cm−1)
3106, 2224, 1643, 1534; HRMS (ESI) m/z [M + Na]+ calcd for
C22H16N2ONa 347.1155; found 347.1129.
(E)-N-(4-Nitrophenyl)-2,3-diphenylacrylamide (5ag). 5ag was
prepared according to general procedure 4. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a yellow solid compound 5ag (28 mg) in 81% yield;
1
mp 140−142 °C; Rf = 0.6 (20% EtOAc/hexane); H NMR (CDCl3,
400 MHz) δ 8.17 (d, J = 8.0 Hz, 2H), 8.01 (s, 1H), 7.62 (d, J = 8.0 Hz,
2H), 7.56−7.54 (m, 3H), 7.47 (br, 1H), 7.38−7.35 (m, 2H), 7.24−7.16
(m, 3H), 7.03 (d, J = 8.0 Hz, 2H); 13C{1H} NMR (CDCl3, 100 MHz) δ
165.5, 143.9, 140.2, 135.5, 134.6, 133.9, 131.0, 130.5, 130.3, 129.7
(2C), 128.7, 125.3, 119.5; IR (KBr, cm−1) 3121, 1682, 1405; HRMS
1
92−94 °C; Rf = 0.6 (10% EtOAc/hexane); H NMR (CDCl3, 400
MHz) δ 8.16 (d, J = 8.0 Hz, 1H), 7.99 (s, 1H), 7.55−7.48 (m, 3H),
7.40−7.38 (m, 2H), 7.24−7.15 (m, 5H), 7.08−7.06 (m, 3H), 7.01 (t, J
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= 8.0 Hz, 1H), 1.81 (s, 3H); 13C{1H} NMR (CDCl3, 100 MHz) δ
165.1, 138.2, 136.5, 136.4, 135.1, 135.0, 130.8, 130.5, 130.3, 130.2,
129.2, 129.1, 128.5, 127.7, 127.2, 124.9, 121.6, 17.3; IR (KBr, cm−1)
3125, 1666, 1401; HRMS (ESI) m/z [M + H]+ calcd for C22H20NO
314.1539; found 314.1525.
cm−1) 3132, 1717, 1675, 1402; HRMS (ESI) m/z [M + H]+ calcd for
C28H31N2O3 443.2329; found 443.2338.
(E)-N-(4-Cyanophenyl)-2,3-di-p-tolylacrylamide (5cf). 5cf was
prepared according to general procedure 4 with a modified temperature
of 80 °C. The crude reaction mixture was purified by column
chromatography using silica gel (230−400 mesh size), giving a yellow
solid compound 5cf (26 mg) in 72% yield; mp 194−195 °C; Rf = 0.2
(E)-N-(2-Chlorophenyl)-2,3-diphenylacrylamide (5an). 5an was
prepared according to general procedure 4. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a pale-yellow solid compound 5an (23 mg) in 70%
1
(10% EtOAc/hexane); H NMR (CDCl3, 400 MHz) δ 7.93 (s, 1H),
7.59−7.54 (m, 4H), 7.40 (br, 1H), 7.33 (d, J = 8.0 Hz, 2H), 7.22 (d, J =
8.0 Hz, 2H), 6.99 (d, J = 8.0 Hz, 2H), 6.93 (d, J = 8.0 Hz, 2H), 2.46 (s,
3H), 2.28 (s, 3H); 13C{1H} NMR (CDCl3, 100 MHz) δ 165.9, 142.2,
139.9, 139.7, 139.5, 133.4, 132.9, 132.6, 132.0, 131.2, 130.9, 130.1,
129.4, 119.9, 119.2, 107.3, 21.7, 21.6; IR (KBr, cm−1) 3288, 2222, 1643,
1406; HRMS (ESI) m/z [M + H]+ calcd for C24H21N2O 353.1648;
found 353.1660.
(E)-2,3-Bis(4-(tert-butyl)phenyl)-N-(4-cyanophenyl)acrylamide
(5df). 5df was prepared according to general procedure 4. The crude
reaction mixture was purified by column chromatography using silica
gel (230−400 mesh size), giving a yellowish liquid compound 5df (20
mg) in 54% yield; Rf = 0.4 (10% EtOAc/hexane); 1H NMR (CDCl3,
400 MHz) δ 7.94 (s, 1H), 7.57−7.55 (m, 6H), 7.39 (br, 1H), 7.28−
7.26 (m, 2H), 7.18 (d, J = 8.8 Hz, 2H), 6.96 (d, J = 8.4 Hz, 2H), 1.42 (s,
9H), 1.25 (s, 9H); 13C{1H} NMR (CDCl3, 100 MHz) δ 165.9, 153.1,
152.8, 142.3, 139.6, 133.4, 132.9, 132.6, 131.9, 130.9, 129.8, 127.4,
125.6, 120.0, 119.2, 107.4, 35.2, 35.0, 31.6, 31.4; IR (KBr, cm−1) 3384,
3130, 2962, 2218, 1692, 1404; HRMS (ESI) m/z [M + H]+ calcd for
C30H33N2O 437.2587; found 437.2578.
(E)-N-(4-Cyanophenyl)-2,3-di-o-tolylacrylamide (5ef). 5ef was
prepared according to general procedure 4 with a modified temperature
of 80 °C. The crude reaction mixture was purified by column
chromatography using silica gel (230−400 mesh size), giving a
yellowish liquid compound 5ef (16 mg) in 46% yield; Rf = 0.5 (10%
EtOAc/hexane); 1H NMR (CDCl3, 400 MHz) δ 8.24 (s, 1H), 7.57 (s,
4H), 7.38−7.34 (m, 1H), 7.32−7.26 (m, 3H), 7.20−7.15 (m, 2H),
7.12−7.08 (m, 1H), 6.81 (t, J = 7.6 Hz, 1H), 6.59 (d, J = 7.6 Hz, 1H),
2.47 (s, 3H), 2.16 (s, 3H); 13C{1H} NMR (CDCl3, 100 MHz) δ 165.6,
142.1, 138.6, 138.2, 137.9, 134.5, 134.0, 133.8, 133.5, 131.6, 130.8,
130.6, 129.7, 129.3, 128.7, 127.5, 125.8, 120.0, 119.1, 107.6, 20.5, 19.9;
IR (KBr, cm−1) 3130, 2224, 1678, 1404; HRMS (ESI) m/z [M + H]+
calcd for C24H21N2O 353.1648; found 353.1643.
(E)-N-(4-Cyanophenyl)-2-ethylpent-2-enamide (5hf). 5hf was
prepared according to general procedure 4 with a modified temperature
of 100 °C. The crude reaction mixture was purified by column
chromatography using silica gel (230−400 mesh size), giving a
yellowish liquid compound 5hf (12 mg) in 55% yield; Rf = 0.7 (30%
EtOAc/hexane); 1H NMR (CDCl3, 400 MHz) δ 7.71−7.69 (m, 3H),
7.61 (d, J = 8.8 Hz, 2H), 6.28 (t, J = 7.6 Hz, 1H), 2.41 (q, J = 7.6 Hz,
2H), 2.24 (pent, J = 7.6 Hz, 2H), 1.08 (m, 6H); 13C{1H} NMR
(CDCl3, 100 MHz) δ 168.1, 142.6, 138.6, 138.2, 133.5, 119.9, 119.2,
107.1, 21.8, 20.7, 14.0, 13.9; IR (KBr, cm−1) 3135, 2223, 1659, 1401;
HRMS (ESI) m/z [M + Na]+ calcd for C14H16N2ONa 251.1155; found
251.1153.
1
yield; mp 107−109 °C; Rf = 0.6 (10% EtOAc/hexane); H NMR
(CDCl3, 400 MHz) δ 8.56 (dd, J = 8.0, 1.6 Hz, 1H), 8.00 (s, 1H), 7.92
(br, 1H), 7.54−7.48 (m, 3H), 7.38 (dd, J = 8.0, 1.6 Hz, 2H), 7.30−7.25
(m, 2H), 7.21−7.14 (m, 3H), 7.08−7.06 (m, 2H), 6.99 (dt, J = 7.6, 1.2
Hz, 1H); 13C{1H} NMR (CDCl3, 100 MHz) δ 165.3, 138.8, 135.8,
135.2, 135.0 (2C), 134.9, 130.9, 130.3, 130.2, 129.3, 129.2, 128.6,
128.0, 124.8, 123.2, 121.4; IR (KBr, cm−1) 3141, 1687, 1401; HRMS
(ESI) m/z [M + Na]+ calcd for C21H16ClNONa 356.0813; found
356.0805.
(E)-N-(2-Acetylphenyl)-2,3-diphenylacrylamide (5ao). 5ao was
prepared according to general procedure 4. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a pale-yellow solid compound 5ao (22 mg) in 65%
1
yield; mp 141−143 °C; Rf = 0.4 (10% EtOAc/hexane); H NMR
(CDCl3, 400 MHz) δ 11.4 (s, 1H), 8.92 (d, J = 8.0 Hz, 1H), 7.91 (s,
1H), 7.80 (dd, J = 8.0, 1.2 Hz, 1H), 7.58−7.51 (m, 4H), 7.36−7.33 (m,
2H), 7.19−7.13 (m, 3H), 7.11−7.03 (m, 3H), 2.48 (s, 3H); 13C{1H}
NMR (CDCl3, 100 MHz) δ 202.0, 167.4, 141.0, 138.5, 136.4, 135.5,
135.3, 135.0, 131.7, 130.8, 130.5, 129.8, 129.0, 128.5 (2C), 123.0,
122.8, 121.5, 28.7; IR (KBr, cm−1) 3152, 1673, 1653, 1401; HRMS
(ESI) m/z [M + Na]+ calcd for C23H19NO2Na 364.1308; found
364.1325.
(E)-N-(Benzo[d]thiazol-2-yl)-2,3-diphenylacrylamide (5ap).23b
5ap was prepared according to general procedure 4. The crude
reaction mixture was purified by column chromatography using silica
gel (230−400 mesh size), giving a pale-yellow solid compound 5ap (23
mg) in 65% yield; mp 198−200 °C; Rf = 0.5 (10% EtOAc/hexane); 1H
NMR (CDCl3, 400 MHz) δ 8.74 (br, 1H), 8.10 (s, 1H), 7.84 (d, J = 8.0
Hz, 1H), 7.69 (d, J = 8.0 Hz, 1H), 7.54−7.53 (m, 3H), 7.42 (t, J = 7.6
Hz, 1H), 7.37−7.34 (m, 2H), 7.31 (t, J = 8.0 Hz, 1H), 7.25−7.23 (m,
1H), 7.18 (t, J = 8.0 Hz, 2H), 7.04 (d, J = 7.6 Hz, 2H); 13C{1H} NMR
(CDCl3, 100 MHz) δ 165.2, 158.3, 148.8, 141.5, 134.5, 134.4, 132.7,
132.3, 131.2, 130.7, 130.3, 130.0, 129.9, 128.7, 126.6, 124.3, 121.7,
121.2; IR (KBr, cm−1) 3140, 1666, 1401; HRMS (ESI) m/z [M + H]+
calcd for C22H17N2OS 357.1056; found 357.1041.
(E)-2,3-Diphenyl-N-(quinolin-8-yl)acrylamide (5aq). 5aq was
prepared according to general procedure 4 with a modified temperature
of 100 °C and reaction time of 7 h (as monitored by TLC). The crude
reaction mixture was purified by column chromatography using silica
gel (230−400 mesh size), giving a brownish solid compound 5aq (18
mg) in 50% yield; mp 168−170 °C; Rf = 0.5 (10% EtOAc/hexane); 1H
NMR (CDCl3, 400 MHz) δ 10.12 (br, 1H), 8.90 (d, J = 8.0 Hz, 1H),
8.47 (br, J = 4.0 Hz, 1H), 8.06 (d, J = 8.0 Hz, 1H), 8.02 (s, 1H), 7.56−
7.53 (m, 4H), 7.47−7.43 (m, 3H), 7.31 (dd, J = 8.0, 4.0 Hz, 1H), 7.21−
7.18 (m, 3H), 7.12 (d, J = 8.0 Hz, 2H); 13C{1H} NMR (CDCl3, 100
MHz) δ 165.8, 148.3, 139.1, 137.9, 136.3, 136.2, 136.1, 135.3, 135.0,
130.9, 130.4, 130.0, 129.0, 128.8, 128.5, 128.1, 127.7, 121.9, 121.7,
116.6; IR (KBr, cm−1) 3140, 1671, 1401; HRMS (ESI) m/z [M + H]+
calcd for C24H19N2O 351.1492; found 351.1480.
(E)-2-(Diethylamino)ethyl 4-(2,3-Diphenylacrylamido)benzoate
(5au). 5au was prepared according to general procedure 4. The
crude reaction mixture was purified by column chromatography using
silica gel (230−400 mesh size), giving a pale-yellow liquid compound
5au (33 mg) in 75% yield; Rf = 0.3 (100% EtOAc); 1H NMR (CDCl3,
400 MHz) δ 7.93 (d, J = 8.4 Hz, 3H), 7.52−7.49 (m, 5H), 7.36−7.34
(m, 2H), 7.30 (br, 1H), 7.18−7.12 (m, 3H), 7.99 (d, J = 7.6 Hz, 2H),
4.34 (t, J = 6.4 Hz, 2H), 2.82 (t, J = 6.4 Hz, 2H), 2.62 (q, J = 7.2 Hz,
4H), 1.05 (t, J = 7.2 Hz, 6H); 13C{1H} NMR (CDCl3, 100 MHz) δ
166.0, 165.0, 142.4, 139.4, 136.1, 135.0, 134.5, 131.1, 130.9, 130.4,
129.4 (2C), 128.6, 126.2, 119.1, 96.5, 63.4, 51.4, 48.1, 12.4; IR (KBr,
(E)-N-(2-hydroxyphenyl)-2,3-diphenylacrylamide (5av). 5av was
prepared according to general procedure 4. The crude reaction mixture
was purified by column chromatography using silica gel (230−400
mesh size), giving a brown solid compound 5av (20 mg, 63% yield) in
both condition A and condition B; mp 175−177 °C; Rf = 0.5 (20%
EtOAc/hexane); 1H NMR (CDCl3, 400 MHz) δ 9.26 (br, 1H), 8.03 (s,
1H), 7.54−7.51 (m, 3H), 7.43 (br, 1H), 7.38−7.36 (m, 2H), 7.23−7.21
(m, 1H), 7.17 (t, J = 8.0 Hz, 2H), 7.11 (dt, J = 8.4, 1.6 Hz, 1H), 7.03
(dd, J = 7.2, 1.6 Hz, 3H), 6.80−6.76 (m, 1H), 6.67 (d, J = 8.0 Hz, 1H);
13C{1H} NMR (CDCl3, 100 MHz) δ 167.2, 149.5, 140.3, 135.5, 134.6,
132.9 (2C), 131.0, 130.5, 130.3, 129.6, 128.6, 127.8, 125.7, 122.6, 120.5
(2C); IR (KBr, cm−1) 3139, 1653, 1401; HRMS (ESI) m/z [M + H]+
calcd for C21H18NO2 316.1332; found 316.1311.
3-Phenylquinolin-2(1H)-one (5aa′).20g 5aa′ was prepared accord-
ing to general procedure 9. The crude reaction mixture was purified by
column chromatography using silica gel (230−400 mesh size), giving a
pink solid compound 5aa′ (19 mg) in 86% yield; Rf = 0.2 (20% EtOAc/
hexane); mp 275−276 °C; 1H NMR (DMSO-d6, 400 MHz) δ 11.98 (s,
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1H), 8.13 (s, 1H), 7.80−7.75 (m, 3H), 7.55−7.51 (m, 1H), 7.48−7.45
(m, 2H), 7.42−7.36 (m, 2 H), 7.23 (t, J = 7.2 Hz, 1H); 13C{1H} NMR
(DMSO-d6, 100 MHz) δ 161.9, 139.3, 138.5, 137.2, 132.4, 131.1, 129.6,
129.0, 128.8, 128.7, 122.8, 120.5, 115.6; IR (KBr, cm−1) 3305, 1652,
1567 1400.
REFERENCES
■
(1) (a) Crabtree, R. H. The Organometallic Chemistry of Alkanes.
Chem. Rev. 1985, 85, 245−269. (b) Jones, W. D. The Fall of the C-C
Bond. Nature 1993, 364, 676−677. (c) Jun, C.-H.; Moon, C. W.; Lee,
H.; Lee, D. Y. Chelation-Assisted Carbon−Carbon Bond Activation by
Rh (I) Catalysts. J. Mol. Catal. A: Chem. 2002, 189, 145−156. (d) Jun,
C.-H. Transition Metal-Catalyzed Carbon-Carbon Bond Activation.
Chem. Soc. Rev. 2004, 33, 610−618. (e) Seiser, T.; Saget, T.; Tran, D.
N.; Cramer, N. Cyclobutanes in Catalysis. Angew. Chem., Int. Ed. 2011,
50, 7740−7752. (f) Murakami, M.; Matsuda, T. Metal-Catalysed
Cleavage of Carbon-Carbon Bonds. Chem. Commun. 2011, 47, 1100−
1105. (g) Ruhland, K. Transition Metal-Mediated Cleavage and
Activation of C−C Single Bonds. Eur. J. Org. Chem. 2012, 2012, 2683−
2706. (h) Chen, F.; Wang, T.; Jiao, N. Recent Advances in Transition
Metal-Catalyzed Functionalization of Unstrained Carbon−Carbon
Bonds. Chem. Rev. 2014, 114, 8613−8661. (i) Souillart, L.; Cramer, N.
Catalytic C−C Bond Activations via Oxidative Addition to Transition
Metals. Chem. Rev. 2015, 115, 9410−9464.
ASSOCIATED CONTENT
* Supporting Information
The Supporting Information is available free of charge at
https://pubs.acs.org/doi/10.1021/acs.joc.0c02700.
■
sı
Mechanistic studies and control experiments, NMR
spectra (1 H, 13C, and 19F) of 3aa −3ha, 5aa −5hf, and
5aa′, and X-ray crystallography data of 3aw and 5aq
(PDF)
FAIR data, including the primary NMR FID files, for
compounds 3aa −3ha, 5aa −5hf, and 5aa′ (ZIP)
Accession Codes
(2) Rybtchinski, B.; Milstein, D. Metal Insertion into C-C Bonds in
Solution. Angew. Chem., Int. Ed. 1999, 38, 870−883.
CCDC 2036075 and 2036076 contain the supplementary
crystallographic data for this paper. These data can be obtained
free of charge via www.ccdc.cam.ac.uk/data_request/cif, or by
emailing data_request@ccdc.cam.ac.uk, or by contacting The
Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: + 44 1223 336033.
(3) (a) Murakami, M.; Matsuda, T. Metal-Catalysed Cleavage of
Carbon-Carbon Bonds. Chem. Commun. 2011, 47, 1100−1105.
(b) Ishida, N.; Sawano, S.; Murakami, M. Stereospecific Ring
Expansion from Orthocyclophanes with Central Chirality to Meta-
cyclophanes with Planar Chirality. Nat. Commun. 2014, 5, 3111.
(c) Okumura, S.; Sun, F.; Ishida, N.; Murakami, M. Palladium
Catalyzed Intermolecular Exchange between C-C and C-Si Sigma
Bonds. J. Am. Chem. Soc. 2017, 139, 12414−12417.
AUTHOR INFORMATION
Corresponding Author
■
(4) (b) Chen, P.; Billett, B. A.; Tsukamoto, T.; Dong, G. Cut and Sew”
Transformations via Transition Metal-Catalyzed Carbon-Carbon Bond
Activation. ACS Catal. 2017, 7, 1340−1360. (c) Deng, L.; Chen, M.;
Dong, G. Concise Synthesis of (−)-Cycloclavine and (−)-5-epi-
Cycloclavine via Asymmetric C−C Activation. J. Am. Chem. Soc. 2018,
140, 9652−9658. (a) Dong, G. C-C Bond Activation. Top. Curr. Chem.
2014, 346, 346.
Ponneri Chandrababu Ravikumar − School of Chemical
Sciences, National Institute of Science Education and Research
(NISER), HBNI, Bhubaneswar 752050, India; orcid.org/
0000-0002-5264-820X; Email: pcr@niser.ac.in
Authors
(5) (a) Wang, G.-W.; Bower, J. F. Modular Access to Azepines by
Directed Carbonylative C−C Bond Activation of Aminocyclopropanes.
J. Am. Chem. Soc. 2018, 140, 2743−2747. (b) Dalling, A. G.; Yamauchi,
T.; McCreanor, N. G.; Cox, L.; Bower, J. F. Carbonylative C−C Bond
Activation of Electron-Poor Cyclopropanes: Rhodium-Catalyzed
(3+1+2) Cycloadditions of Cyclopropylamides. Angew. Chem., Int.
Ed. 2019, 58, 221−225. (c) Ma, X. F.; Hazelden, I. R.; Langer, T.;
Munday, R. H.; Bower, J. F. Enantioselective aza-Heck cyclizations of
N-(tosyloxy)carbamates: Synthesis of pyrrolidines and piperidines. J.
Am. Chem. Soc. 2019, 141, 3356−3360. (d) Wang, G.-W.; Boyd, O.;
Young, T. A.; Bertrand, S. M.; Bower, J. F. Rhodacyclopentanones as
Linchpins for the Atom Economical Assembly of Diverse Polyhetero-
cycles. J. Am. Chem. Soc. 2020, 142, 1740−1745. (e) Sokolova, O. O.;
Bower, J. F.; Selective Carbon−Carbon Bond Cleavage of Cyclo-
propylamine Derivatives. Chem. Rev. 2020 DOI: 10.1021/acs.chem-
rev.0c00166.
Tanmayee Nanda − National Institute of Science Education and
Research (NISER), HBNI, Bhubaneswar 752050, India;
orcid.org/0000-0001-6875-689X
Pragati Biswal − National Institute of Science Education and
Research (NISER), HBNI, Bhubaneswar 752050, India
Bedadyuti Vedvyas Pati − National Institute of Science
Education and Research (NISER), HBNI, Bhubaneswar
752050, India
Shyam Kumar Banjare − National Institute of Science
Education and Research (NISER), HBNI, Bhubaneswar
752050, India
Complete contact information is available at:
https://pubs.acs.org/10.1021/acs.joc.0c02700
(6) (a) Li, H.; Li, Y.; Zhang, X.-S.; Chen, K.; Wang, X.; Shi, Z.-J.
Pyridinyl directed alkenylation with olefins via Rh(III)-catalyzed CC
bond cleavage of secondary arylmethanols. J. Am. Chem. Soc. 2011, 133,
15244−15247. (b) Chen, K.; Li, H.; Lei, Z.-Q.; Li, Y.; Ye, W.-H.;
Zhang, L.-S.; Sun, J.; Shi, Z.-J. Reductive cleavage of the Csp2-Csp3
bond of secondary benzyl alcohols: rhodium catalysis directed by N-
containing groups. Angew. Chem., Int. Ed. 2012, 51, 9851−9855.
(c) Souillart, L.; Parker, E.; Cramer, N. Highly Enantioselective
Rhodium(I)-Catalyzed Activation of Enantiotopic Cyclobutanone C-C
Bonds. Angew. Chem., Int. Ed. 2014, 53, 3001−3005. (d) Kumar, N. Y.;
Bechtoldt, A.; Raghuvanshi, K.; Ackermann, L. Ruthenium (II)-
Catalyzed Decarboxylative C−H Activation: Versatile Routes to meta-
Alkenylated Arenes. Angew. Chem., Int. Ed. 2016, 55, 6929−6932.
(e) Onodera, S.; Ishikawa, S.; Kochi, T.; Kakiuchi, F. Direct
Alkenylation of Allylbenzenes via Chelation Assisted C−C Bond
Cleavage. J. Am. Chem. Soc. 2018, 140, 9788−9792. (f) Qiu, Y.;
Scheremetjew, A.; Ackermann, L. Electro-Oxidative C−C Alkenylation
by Rhodium (III) Catalysis. J. Am. Chem. Soc. 2019, 141, 2731−2738.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
We are thankful to NISER, the Department of Atomic Energy
(DAE), the Council for Scientific and Industrial Research
(CSIR), New Delhi (Grant 02(0256)/16/EMR II), and the
Science and Engineering Research Board (SERB), New Delhi
(Grant EMRII/2017/001475) for the financial support. Ms.
Tanmayee Nanda, Mr. Pragati Biswal, and Mr. Shyam Kumar
Banjare thank DAE and Mr. Bedadyuti Vedavyas Pati thanks
DST INSPIRE for research fellowships. We are thankful to Dr.
Asit Ghosh NISER Bhubaneswar for helpful discussions. We are
also thankful to Mr. Ranjit Mishra, NISER Bhubaneswar, for GC
analysis and Mr. Shreenibas Sa and Ms. Syamasrit Dash for
solving the XRD structure.
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pubs.acs.org/joc
Article
(7) (a) Chen, P.-H.; Dong, G. Cyclobutenones and Benzocyclobu-
tenones: Versatile Synthons in Organic Synthesis. Chem. - Eur. J. 2016,
22, 18290−18315. (c) Wang, J.; Blaszczyk, S. A.; Li, X.; Tang, W.
Transition Metal-Catalyzed Selective Carbon−Carbon Bond Cleavage
of Vinylcyclopropanes in Cycloaddition Reactions. Chem. Rev. 2020,
DOI: 10.1021/acs.chemrev.0c00160. (d) Ishida, N.; Murakami, M.
Cleavage of Carbon−Carbon σ-Bonds of Four-Membered Rings.
Chem. Rev. 2020, DOI: 10.1021/acs.chemrev.0c00569. (b) Deng, L.;
Dong, G. Carbon−Carbon Bond Activation of Ketones. Trends in
Chemistry 2020, 2, 183.
13, 1791−1797. (e) Buchanan, M. S.; Carroll, A. R.; Addepalli, R.;
Avery, V. M.; Hooper, J. N. A.; Quinn, R. J. J. Psammaplysenes C and D,
Cytotoxic Alkaloids from Psammoclemma sp. J. Nat. Prod. 2007, 70,
1827−1829. (f) Roughley, S. D.; Jordan, A. M. The Medicinal
Chemist’s Toolbox: An Analysis of Reactions Used in the Pursuit of
Drug Candidates. J. Med. Chem. 2011, 54, 3451−3479.
(12) For selected books and reviews, see: (a) In Advanced Organic
Chemistry, 5th ed.; Smith, M. B., March, J., Eds.; Wiley-VCH: New
York, 2001. (b) In Modern Aldol Reactions; Mahrwald, R., Ed.; Wiley-
VCH: Weinheim, Germany, 2004. (c) Nielsen, A. T.; Houlihan, W. J.
The Aldol Condensation. Org. React. 2011, 16, 1−438.
(8) Pati, B. V.; Ghosh, A.; Ravikumar, P. C. Rhodium-Catalyzed Room
Temperature C−C Activation of Cyclopropanol for One-Step Access
to Diverse 1,6-Diketones. Org. Lett. 2020, 22 (7), 2854−2860.
(9) (a) Baba, A.; Ohshiro, Y.; Agawa, T. Reactions of diphenylcyclo-
propenone with ketenes in the presence of nickel tetracarbony. J.
Organomet. Chem. 1976, 110, 121−127. (b) Wender, P. A.; Paxton, T.
J.; Williams, T. J. Cyclopentadienone Synthesis by Rhodium(I)-
Catalyzed [3 + 2] Cycloaddition Reactions of Cyclopropenones and
Alkynes. J. Am. Chem. Soc. 2006, 128, 14814−14815. (c) Matsuda, T.;
Sakurai, Y. Palladium-Catalyzed Ring-Opening Alkynylation of Cyclo-
propenones. Eur. J. Org. Chem. 2013, 2013, 4219−4222. (d) Xu, J.; Cao,
J.; Fang, C.; Lu, T.; Du, D. Organocatalytic C-C Bond Activation of
Cyclopropenones for the Ring-Opening Formal [3 + 2] Cycloaddition
with Isatins. Org. Chem. Front. 2017, 4, 560−564. (e) Kong, L. H.;
Zhou, X.-K.; Xu, Y.-W.; Li, X.-W. Rhodium (III) Catalyzed Acylation of
C (sp3)-H Bonds with Cyclopropenones. Org. Lett. 2017, 19, 3644−
3647. (f) Ren, J.-T.; Wang, J.-X.; Tian, H.; Xu, J.-L.; Hu, H.; Aslam, M.;
Sun, M. Ag(I)-Catalyzed [3 + 2]-Annulation of Cyclopropenones and
Formamides via C−C Bond Cleavage. Org. Lett. 2018, 20, 6636−6639.
(g) Zhao, W.-T.; Gao, F.; Zhao, D. Intermolecular σ-Bond Cross
Exchange Reaction between Cyclopropenones and (Benzo)-
silacyclobutanes: Straightforward Access towards Sila-(benzo)-
cycloheptenones. Angew. Chem. 2018, 130, 6437−6440. (h) Haito,
A.; Chatani, N. Rh (I)-Catalyzed [3 + 2] annulation reactions of
cyclopropenones with amides. Chem. Commun. 2019, 55, 5740−5742.
(10) (a) Tawata, S.; Taira, S.; Kobamoto, N.; Zhu, J.; Ishihara, M.;
Toyama, S. Synthesis and antifungal activity of cinnamic acid esters.
Biosci., Biotechnol., Biochem. 1996, 60, 909−910. (b) Natella, F.;
Nardini, M.; Di Felice, M.; Scaccini, C. Benzoic and cinnamic acid
derivatives as antioxidants: structure-activity. J. Agric. Food Chem. 1999,
47, 1453−1459. (c) Zhu, J.; Majikina, M.; Tawata, S. Syntheses and
Biological Activities of Pyranyl substituted Cinnamates. Biosci.,
Biotechnol., Biochem. 2001, 65, 161−163. (d) Gobec, S.; Sova, M.;
Kristan, K.; Lanisnik Rizner, T. Cinnamic acid esters as potent
inhibitors of fungal 17-hydroxysteroid dehydrogenase - a model enzyme
of the short-chain dehydrogenase/reductase superfamily. Bioorg. Med.
Chem. Lett. 2004, 14, 3933−3936. (e) Narasimhan, B.; Belsare, D.;
Pharande, D.; Mourya, V.; Dhake, A. Esters, amides and substituted
derivatives of cinnamic acid: synthesis, antimicrobial activity and QSAR
investigations. Eur. J. Med. Chem. 2004, 39, 827−834. (f) Sova, M.;
Perdih, A.; Kotnik, M.; Kristan, K.; Rizner, T. L.; Solmajer, T.; Gobec, S.
Flavonoids and cinnamic acid esters as inhibitors of fungal 17b-
hydroxysteroid dehydrogenase: A synthesis, QSAR and modelling
study. Bioorg. Med. Chem. 2006, 14, 7404−7418. (g) Ruiz, D. M.;
Romanelli, G. P.; Bennardi, D. O.; Baronetti, G. T.; Thomas, H. J.;
Autino, J. C. Direct esterification of cinnamic acids with phenols and
imidoalcohols: a simple, heteropolyacid-catalyzed procedure. ARKI-
VOC 2008, 2008, 269−276.
(13) (a) Maercker, A. The Wittig reaction. Org. React. 1965, 14, 270−
490. (b) In Some Modern Methods of Organic Synthesis; Carruthers, W.,
Ed.; Cambridge University Press: Cambridge, U.K., 1971. (c) Maryan-
off, B. E.; Reitz, A. B. The Wittig olefination reaction and modifications
involving phosphoryl-stabilised carbanions. Stereochemistry, mecha-
nism and selected synthetic aspects. Chem. Rev. 1989, 89, 863−927.
(14) (a) Boutagy, J.; Thomas, R. Olefin Synthesis with Organic
Phosphonate Carbanions. Chem. Rev. 1974, 74, 87−99. (b) Wadsworth,
W. S., Jr. Synthetic applications of phosphorylstabilized anions. Org.
React. 1977, 25, 73−253. (c) Kelly, S. E. In ComprehensiVe Organic
Synthesis; Trost, B. M., Fleming, I., Eds.; Pergamon: Oxford, UK, 1991;
Vol. 1, p 729.
(15) (a) In Handbook of Reagents for Organic Synthesis: Activating
Agents and Protecting Groups; Pearson, A. J., Roush, W. R., Eds.; Wiley-
VCH: New York, 1999. (b) Montalbetti, C. A. G. N.; Falque, V. Amide
bond formation and peptide coupling. Tetrahedron 2005, 61, 10827−
10852. (c) Valeur, E.; Bradley, M. Amide Bond Formation: Beyond the
Myth of Coupling Reagents. Chem. Soc. Rev. 2009, 38, 606−631.
(d) Pattabiraman, V. J.; Bode, J. W. Rethinking amide bond synthesis.
Nature 2011, 480, 471−479. (e) de Figueiredo, R. M.; Suppo, J.-S.;
Campagne, J.-M. Nonclassical Routes for Amide Bond Formation.
Chem. Rev. 2016, 116, 12029−12122.
(16) Kuniyasu, H.; Yoshizawa, T.; Kambe, N. Palladium-catalyzed
hydro phenoxy carbonylation of internal alkynes by phenol and CO: the
use of Zn for the formation of active catalyst. Tetrahedron Lett. 2010, 51,
6818−6821.
(17) (a) Park, J. H.; Kim, S. Y.; Kim, S. M.; Chung, Y. K. Cobalt−
Rhodium Heterobimetallic Nanoparticle-Catalyzed Synthesis of α,β-
Unsaturated Amides from Internal Alkynes, Amines, and Carbon
Monoxide. Org. Lett. 2007, 9, 2465−2468. (b) Fujihara, T.; Katafuchi,
Y.; Iwai, T.; Terao, J.; Tsuji, Y. Palladium-Catalyzed Intermolecular
Addition of Formamides to Alkynes. J. Am. Chem. Soc. 2010, 132,
2094−2098.
(18) (a) Chenniappan, V. K.; Rahaim, R. J. Titanium-Promoted Cross
Coupling for the Selective Synthesis of Polysubstituted, Conjugated
Amides. Org. Lett. 2016, 18, 5090−5093. (b) Katafuchi, Y.; Fujihara, T.;
Iwai, T.; Terao, J.; Tsuji, Y. Palladium-Catalyzed Hydroesterification of
Alkynes Employing Aryl Formates without the Use of External Carbon
Monoxide. Adv. Synth. Catal. 2011, 353, 475−482.
(19) Nanda, T.; Ravikumar, P. C. A Palladium-Catalyzed Cascade C−
C Activation of Cyclopropenone and Carbonylative Amination: Easy
Access to Highly Functionalized Maleimide Derivatives. Org. Lett.
2020, 22, 1368−1374.
(20) (a) Manimaran, T.; Natarajan, M.; Ramakrishnan, V. T.
Synthesis of 3-methyl-coumarins, -thiacoumarins and-carbostyrils.
Proc. - Indian Acad. Sci. 1979, 88, 125−130. (b) Grasa, G. A.; Viciu,
M. S.; Huang, J.; Nolan, S. P. Amination Reactions of Aryl Halides with
Nitrogen-Containing Reagents Mediated by Palladium/Imidazolium
Salt Systems. J. Org. Chem. 2001, 66, 7729−7737. (c) Ito, N.; Watahiki,
T.; Maesawa, T.; Maegawa, T.; Sajiki, H. Synergistic Effect of a
Palladium-on-Carbon/Platinum-on-Carbon Mixed Catalyst in Hydro-
gen/Deuterium Exchange Reactions of Alkyl-Substituted Aromatic
Compounds. Adv. Synth. Catal. 2006, 348, 1025−1028. (d) Molina de
la Torre, J. A.; Espinet, P.; Albeniz, A. C. Solvent-Induced Reduction of
Palladium-Aryls, a Potential Interference in Pd Catalysis. Organo-
metallics 2013, 32, 5428−5434. (e) Shan, L.; Wu, G.; Liu, M.; Gao, W.;
Ding, J.; Huang, X.; Wu, H. α. β-Diaryl Unsaturated Ketones via
Palladium-Catalyzed Ring-Opening of Cyclopropenones with Organo-
(11) (a) In The Amide Linkage: Selected Structural Aspects in Chemistry,
Biochemistry and Materials Science; Greenberg, A., Breneman, C. M.,
Liebman, J. F., Eds.; Wiley-VCH: New York, 2000. (b) Caulfield, M. J.;
Qiao, G. G.; Solomon, D. H. Some Aspects of the Properties and
Degradation of Polyacrylamides. Chem. Rev. 2002, 102, 3067−3084.
(c) Dugger, R. W.; Ragan, J. A.; Ripin, D. H. B. Development of a Pilot-
Plant-Scale Synthesis of an Alkylated Dihydrobenzothiadiazole S,S-
Dioxide: Incorporation of a Late-Stage Mitsunobu Reaction. Org.
Process Res. Dev. 2005, 9, 253−258. (d) Hung, C.-C.; Tsai, W.-J.; Kuo,
L.-M. Y.; Kuo, Y.-H. Evaluation of caffeic acid amide analogues as anti-
platelet aggregation and anti-oxidative agents. Bioorg. Med. Chem. 2005,
2694
https://dx.doi.org/10.1021/acs.joc.0c02700
J. Org. Chem. 2021, 86, 2682−2695

The Journal of Organic Chemistry
pubs.acs.org/joc
Article
boronic Acids. Org. Chem. Front. 2018, 5, 1651−1654. (f) Zhao, Q.;
Meng, G.; Nolan, S. P.; Szostak, M. N-Heterocyclic Carbene
Complexes in C-H Activation Reactions. Chem. Rev. 2020, 120,
́
1981−2048. (g) Reyes-Batlle, M.; Freijo, M. B.; Lopez-Arencibia, A.;
Lorenzo-Morales, J.; McNaughton-Smith, G.; Pinero, J. E.; Abad-
̃
Grillo, T. Identification of N-acyl quinolin-2(1H)-ones as new selective
agents against clinical isolates of Acanthamoeba keratitis. Bioorg. Chem.
2020, 99, 103791.
(21) (a) Similar information was reported, see: Banjare, S. K.; Nanda,
T.; Ravikumar, P. C. Cobalt-Catalyzed Regioselective Direct C-4
Alkenylation of 3-Acetylindole with Michael Acceptors Using a Weakly
Coordinating Functional Group. Org. Lett. 2019, 21, 8138−8143.
(b) Gottlieb, H. E.; Kotlyar, V.; Nudelman, A. NMR chemical shifts of
common laboratory solvents as trace impurities. J. Org. Chem. 1997, 62,
7512.
(22) (a) Netland, K. A.; Gundersen, L.-L.; Rise, F. An improved
synthesis of dialkylcyclopropenones. Synth. Commun. 2000, 30, 1767−
1777. (b) Kuzmanich, G.; Gard, M.-N.; Garcia-Garibay, M. A. Photonic
amplification by a singlet-state quantum chain reaction in the
photodecarbonylation of crystalline diarylcyclopropenones. J. Am.
Chem. Soc. 2009, 131, 11606−11614. (c) Poloukhtine, A.; Popik, V. V.
Highly efficient photochemical generation of a triple bond: Synthesis,
properties, and photodecarbonylation of cyclopropenones. J. Org.
Chem. 2003, 68, 7833−7840. (d) Vanos, C. M.; Lambert, T. H.
Development of a Catalytic Platform for Nucleophilic Substitution:
Cyclopropenone-Catalyzed Chlorodehydration of Alcohols. Angew.
Chem., Int. Ed. 2011, 50, 12222−12226. (e) Shih, H.-W.; Prescher, J. A.
A bioorthogonal ligation of cyclopropenones mediated by triarylphos-
phines. J. Am. Chem. Soc. 2015, 137, 10036−10039.
(23) (a) Eicher, T.; Boehm, S.; Ehrhardt, H.; Harth, R.; Lerch, D. On
the Reaction of Diphenylcyclopropenone, its Functional Derivatives
and Imonium Salts with Amines. Liebigs Ann. Chem. 1981, 1981, 765−
788. (b) Kascheres, A.; Reyes R, J. L.; Fonseca, S. M. Fonseca Reaction
of Diphenylcyclopropenone with 2-Aminothiazoles and Related
Compounds. Kascheres, A..; Reyes, J. -L.; Fonesca, S.-M. Heterocycles
1984, 22, 2529−2540. (c) Nakaya, R.; Yasuda, S.; Yorimitsu, H.;
Oshima, K. Rhodium-Catalyzed Intermolecular [2 + 2] Cycloaddition
of Terminal Alkynes with Electron-Deficient Alkenes. Chem. - Eur. J.
2011, 17, 8559−8561. (d) Fan, T.; Wang, A.; Li, J.-Q.; Ye, J.-L.; Zheng,
X.; Huang, P.-Q. Versatile One-Pot Synthesis of Polysubstituted
Cyclopent-2-eniminesfrom α,β-Unsaturated Amides:Imino-Nazarov-
Reaction. Angew. Chem., Int. Ed. 2018, 57, 10352−10356. (e) Peng, J.-
B.; Geng, H.-Q.; Wu, F.-P.; Li, D.; Wu, X.-F. Selectivity Controllable
Divergent Synthesis of α,β-Unsaturated Amides and Maleimides from
Alkynes and Nitroarenes via Palladium-Catalyzed Carbonylation. J.
Catal. 2019, 375, 519−523.
2695
https://dx.doi.org/10.1021/acs.joc.0c02700
J. Org. Chem. 2021, 86, 2682−2695