Transition-Metal-Free Superbase-Catalyzed C-H Vinylation of Aldimines with Acetylenes to 1-Azadienes

Article abstract of DOI:10.1021/acs.joc.9b03192

Aldimines react with aryl- and hetarylacetylenes in the presence of KOBu^t/dimethyl sulfoxide (DMSO) or NaOBu^t/DMSO systems under exceptionally mild conditions (14 °C, 1 h) to afford C-H-vinylated products, 1-azadienes of E configuration relative to the C-C bond, in up to 72% yield. Vinylation involves the unprecedentedly fast multiposition proton transfer in the intermediate adducts of acetylene to the C≠N bond. This new Csp²-Csp² bond-forming reaction opens a straightforward pot-, atom-, step-, and energy-economic access to synthetically valuable 1-azadienes.

Full text of DOI:10.1021/acs.joc.9b03192

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Article
Transition Metal-Free Superbase-Catalyzed C-H
Vinylation of Aldimines with Acetylenes to 1-Azadienes
Elena Yu Schmidt, Ivan A. Bidusenko, Nadezhda I. Protsuk, Yan Demyanov,
Igor A. Ushakov, Alexander Valentine Vashchenko, and Boris A. Trofimov
J. Org. Chem., Just Accepted Manuscript • DOI: 10.1021/acs.joc.9b03192 • Publication Date (Web): 04 Feb 2020
Downloaded from pubs.acs.org on February 6, 2020
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Transition Metal-Free Superbase-Catalyzed C-H Vinylation of Aldimines
with Acetylenes to 1-Azadienes
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Elena Yu. Schmidt, Ivan A. Bidusenko, Nadezhda I. Protsuk, Yan V. Demyanov, Igor A.
Ushakov, Alexander V. Vashchenko and Boris A. Trofimov*
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A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of
Sciences, 1 Favorsky St., Irkutsk 664033, Russian Federation
E-mail: boris_trofimov@irioch.irk.ru
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Graphical abstract
new Csp2-Csp2 bond forming reaction
R3
R1
R3
R1
KOBut/DMSO/THF
14 oC, 1h
one pot
+
one synthetic step
100% atom-economy
up to 72% yield
N
N
R2
R2
simple and readily available
starting materials
inexpensive catalytic system
mild conditions
ABSTRACT: Aldimines react with aryl- and hetarylacetylenes in the presence of KOBut/DMSO
o
or NaOBut/DMSO systems under exceptionally mild conditions (14 C, 1 h) to afford the C-H-
vinylated products, 1-azadienes of E configuration relative to the C-C bond, in up to 72% yield.
The vinylation involves the unprecedentedly fast multi-position proton transfer in the intermediate
adducts of acetylene to the C=N bond. This new Csp2-Csp2 bond forming reaction opens a
straightforward pot-, atom-, step-, and energy-economic access to synthetically valuable 1-
azadienes.
INTRODUCTION
In modern organic synthesis, the criteria of efficiency, versatility, pot-atom-step-economy
are of paramount importance. Therefore, nowadays there is an increasing demand for the
development of strategies that allow the transformation of readily available precursors into the
target products in a rapid, economical and efficient manner.1 In this context, the application of
acetylenes is one of the mainstreams2 due to exceptionally high reactivity of the triple bond and
the possibility of rendering atom-economic and energy-saving processes via diverse addition and
cycloaddition reactions. Acetylenes as reactants especially fit the construction of unsaturated
heteroatomic compounds, among which α,β-unsaturated imines, also called 1-azadienes, attract
great attention as versatile building blocks in organic chemistry3 and privileged intermediates in
total syntheses of natural molecules.4 They serve as useful platform to create molecular complexity
and diversity because of their multi-faceted reactivity acting as nucleophiles (due to the presence
of the electron-rich nitrogen atom), electrophiles (addition reactions), dienes (cycloaddition
reactions) and dienophiles (both the alkene and the imine functionality).3
The most popular synthesis of 1-azadienes is the condensation of α,β-unsaturated carbonyl
compounds with primary amines.3a,b However, this reaction is often complicated by the competing
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Michael addition.5 To overcome this problem, various combinations of the Wittig reaction are
used, e.g. interaction of α-imino phosphonium ylides with aldehydes6 or α,β-unsaturated carbonyl
compounds with phosphazenes.7 Also, the olefination of β-phosphorated imines or enamines with
aldehydes is an alternative.8 A shortcoming of these approaches is the formation of equimolar
amount of phosphorus-containing by-product. Other syntheses are based on transition metal-
catalyzed enyne hydroamination,9 hydroamination/hydroalkylation of terminal alkynes,10
carboamination of diarylalkynes with aldimines,11 cross-coupling of arylhalides with
propargylamines12 and imidoyl halides with alkenes.13 In a one special case, a similar 1-azadiene
was obtained by acid-catalyzed reaction of N-(2,6-dimethylphenyl)-1-phenylmethanimine and
phenylacetylene.14
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Owing to immense synthetic potential of 1-azadienes, efficient pot-atom-step-economic
approaches to their synthesis from the available starting materials under transition metal-free
conditions are highly sought.
In 2012, the transition metal-free α-C-H vinylation of ketones with acetylenes, i.e. a new
Csp3-Csp2 bond constructing reaction, catalyzed by the superbase systems, such as alkali metal
hydroxide (alkoxide)/DMSO was discovered (Scheme 1, A)15 and since then it has been actively
exploited. Recently, we have disclosed the superbase-catalyzed (KOBut/DMSO) ethynylation of
the C=N bond of ketimines (Scheme 1, B), i.e. another new Csp3-Csp bond constructing reaction.16
In a degree, this reaction represents an analogue of Favorsky ethynylation of ketones and was
referred by us as the “aza-Favorsky” reaction.
Scheme 1. Previous and Present Works
15
A
. C-H Vinylation of ketones with acetylenes
R2
R2
R1
MOR/DMSO
R1
R3
R3
+
100 oC, 30-60 min
O
O
R1,R2=H, alkyl, (het)aryl; R3=(het)aryl; M=Na, K, Cs; R=H, But
16
B
. Ethynylation of ketimines with acetylenes
R2
R1 R2
KOBut/DMSO
R1
R4
R4
+
20-40 °C, 10-60 мин
N
HN
R3
R3
R1,R2=alkyl, (het)aryl; R3=(het)aryl; R4=H, (het)aryl
C
R1
. This work
R3
R3
R1
KOBut/DMSO
+
N
R2
N
R2
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Since the latter reaction (Scheme 1, B)16 was implemented using ketimines as a source of
widespread C=N bond, it was logical to evaluate generality of the process, i.e. to determine its
substrate scope relative to another family of ubiquitous C=N electrophiles like aldimines
(aldehyde/amine Schiff adducts). Surprisingly, our preliminary experiments have shown that
aldimines react with acetylenes under mild conditions to form, instead of the expected
propargylamines, 1-azadienes (Scheme 1, C). Virtually, we have encountered with a new Csp2-
Csp2 bond building process, a kind of benzoin condensation.
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RESULTS AND DISCUSSION
For optimization of the synthesis, we have chosen, as a reference, the reaction of aldimine
1a (benzaldehyde/aniline adduct) and phenylacetylene 2a. In order to determine the provisionally
optimum conditions, we have first evaluated the effect of the base nature and its content in DMSO
on the yield of 1-azadiene 3a (Table 1).
Table 1. Effect of base nature and its content on the yield of 3aa
Ph
Ph
Ph
Ph
+
Base/DMSO
20 oC, 10 min
N
N
3a
Ph
Ph
2a
1a
conversion of 1a
yield of 3a
entry
1
2
3
4
5
6
7
8
base
KOBut
KOBut
KOBut
KOBut
KOBut
NaOBut
LiOBut
KOH
1a:baseb
1:1
(%)c
100
100
100
90
(%)d
7
1:0.5
1:0.2
1:0.1
1:0.05
1:0.2
1:0.2
1:0.2
1:0.2
1:0.2
1:0.2
15
52
49
17
46
31
23
10
0
20
91
57
43
15
0
0
9
10
11
NaOH
K2CO3
Et3N
0
aConditions: 1a (1 mmol), 2a (1 mmol), base (0.05-1 mmol), DMSO (3 mL),
20 oC, 10 min. bMolar ratio. cAccording to 1H NMR data of the crude product
(n-dodecane was used as an internal standard). dIsolated yield after column
chromatography (SiO2, n-hexane/diethyl ether, 50:1).
The selected results (Table 1) show that the reaction proceeds with both hydroxides and
alkoxides of alkali metals, however, the best yields of 3a were reached in the KOBut/DMSO (52%)
and NaOBut/DMSO (46%) systems (1a:MOBut molar ratio = 1:0.2, entries 3,6).
Next, using the KOBut as a major component of the superbase system, we have examined
the effects of the second component of the superbase (polar nonhydroxylic solvent acting as a
ligand relative to K+), reaction temperature and time on the process efficiency.
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As can be seen from the representative results (Table 2), the KOBut/DMSO superbase pair
turned out to be the best catalytic system (entry 5). The KOBut/DMF pair showed low activity
(entry 2), and other KOBut/ligand combinations were inactive at all. Then, we tried to increase the
yield of 3a by temperature and time variation. Indeed, carrying out the reaction at 17 oC (further
cooling led to the crystallization of the reaction mixture) increased the yield of 3a to 60% for 1 h
(entry 7). As follows from Table 2 data, the final product 3a is able to undergo secondary
transformations under the reaction conditions. In fact, when the reaction time increased to 2 h
(entry 8), the yield of 3a dropped to 39%. Certain instability of azadiene 3a under the reaction
conditions is evidenced by the formation of noticeable amounts of polymeric products, which
maybe resulted from its further condensation. Additionally, chemical evolution of the final product
during the synthesis was confirmed by the special experiment, when pure 3a was kept in the
KOBut/DMSO system (17 oC, 1 h), its content decreased by ~30%. All this urged us to implement
the synthesis at a lower temperature. To further decrease the reaction temperature, 10 vol.% THF
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o
was added to DMSO that permitted the process to be conducted at 14 C without freezing the
catalytic solution. This enabled to increase the yield of 3a up to 72% (entry 14).
Table 2. Effect of ligand, temperature, and time on the yield of azadiene 3aa
Ph
Ph
Ph
Ph
KOBut/Solvent
T (°C), t (min)
+
N
N
3a
Ph
Ph
1a
2a
entry
1
2
3
4
5
6
7
8
ligand
THF
DMF
T (oC) t (min) conversion of 1a (%)b
yield of 3a (%)c
20
20
20
20
20
17
17
17
16
16
16
14
14
14
14
10
10
10
10
10
10
60
120
10
10
60
15
30
60
60
0
47
0
0
100
86
96
100
77
100
100
96
0
27
0
NMP
dioxane
DMSO
DMSO
DMSO
DMSO
0
52
46
60
39
34
53
0
60
62
72
70
9
DMSO/H2O (100:1)d
DMSO/HOBut (20:1)d
DMSO/NMP (10:1)d
DMSO/THF (10:1)d
DMSO/THF (10:1)d
DMSO/THF (10:1)d
DMSO/THF (10:1)d
10
11
12
13
14
15e
98
100
100
aConditions: 1a (1 mmol), 2a (1 mmol), KOBut (0.2 mmol), solvent (3 mL). bAccording to 1H NMR
data of the crude product. Isolated yield (SiO2, n-hexane/diethyl ether, 50:1). Volume ratio. 2a (2
c
d
e
mmol).
The structure and stereochemistry of compound 3a (1E,2E-isomer) was determined by X-
1
ray analysis (See the Supporting Information). NMR spectra analysis (COSY, NOESY, H-13C,
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and 1H-15N HMBC experiments) shows that azadiene 3a in CDCl3 presents as a mixture of 1E,2E-
and 1Z,2E-isomers in 3:1 ratio, respectively (Fig. 1).
5
H
H
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9
H
H
H
(1E,2E)
(1Z,2E)
H
H
3J = 16.2 Hz
H
H
H
3J = 16.4 Hz
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N
N
-49.7 ppm
-45.9 ppm
Figure 1. Main NOESY correlations for azadiene 3a
With the provisionally optimum conditions established, we have investigated the substrate
scope of the reaction. First, we have changed aldimine 1 structure, while retaining phenylacetylene
2a as a reference (Table 3).
Table 3. Scope of aldiminesa
Ph
R1
Ph
R1
+
KOBut/DMSO/THF
14 oC, 1h
N
N
R2
1a-o
R2
3a-n
2a
Ph
Ph
Ph
Me
MeO
N
N
N
Ph
Ph
Ph
3a, 72%
3b, 61% (93%)
3c, 70%
OMe
Ph
F
Ph
Cl
MeO
Ph
MeO
Br
N
N
N
Ph
Ph
Ph
3d, 39%
3e, 61%
3f, 50% (85%)
Ph
Ph
Ph
O
S
N
N
N
Ph
Ph
Ph
3g, 42% (74%)
3h, 56%
3i, 58% (75%)
Ph
Ph
Ph
Ph
N
Ph
N
Ph
N
OMe
F
Me
3j, 59% (96%)
3k, 58%
3l, 64%
Ph
Ph
Ph
Ph
Ph
N
N
Ph
N
Bun
Br
3m, 33% (68%)
3n, 43%
3o, 0% (0%)
aConditions: 1 (1 mmol) in DMSO (0.5 mL) was added dropwise to a mixture of 2a (1 mmol), KOBut
(0.2 mmol), THF (0.3 mL) in DMSO (3 mL) at 14 oC for 1 min. The resulting mixture was stirred at 14
oC for 1 h. Isolated yields after column chromatography (SiO2, n-hexane/diethyl ether) are given. In
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parentheses, conversion of aldimine 1 (determined by 1H NMR data of the crude reaction mixtures) is
given; in all other cases the conversion is complete.
As follows from Table 3, the synthesis was successfully extended over aldimines derived
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from aryl and hetaryl substituted aldehydes and arylamines, the yields of azadienes 3a–n being
33-72%. In the aldehyde counterpart, along with unsubstituted phenyl, the benzene ring is
substituted by alkyl, alkoxy, fluorine, bromine, chlorine groups, and the hetaryls are furyl and
thienyl. The aldimines derived from aliphatic aldehydes and aromatic amines are much less
accessible compounds. To our knowledge, no synthetically acceptable protocols exist in literature.
The amine counterpart contains phenyl, 2-methyl-, 4-methoxy-, 2-fluoro-, 2-bromophenyl, and
condensed aromatic substituent (2-naphthyl).
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In some cases, the reaction proceeded with incomplete conversion of the starting aldimine.
As to the influence of aldimine 1 structure on azadiene 3 yield, the results obtained show no clear
regularity in the substituents effect on the process efficiency. As exemplified by imine 1o (R2 =
Bun), donor effect of the alkyl substituent completely suppresses the reaction probably due to
depolarization of the C=N bond, i.e. decreasing its electrophilicity.
The scope of acetylene substrates has been examined for the reference aldimine 1a (Table
4).
Table 4. Scope of acetylenesa
R3
Ph
R3
2b-l
Ph
KOBut/DMSO/THF
14 °C, 1 h
+
N
N
Ph
Ph
3p-y
1a
Me
Me
Ph
Me
Me
Ph
Ph
Ph
Ph
N
N
N
N
Ph
Ph
Ph
Ph
3p, 64%
3q, 53%
3r, 31%
3s, 43%
F
OMe
OMe
F
Ph
Ph
Ph
Ph
N
N
N
N
Ph
Ph
Ph
Ph
3t, 43%
3u, 63%
3v, 60%
3w, 56%
Me
Me
Me
S
N
Ph
Ph
N
Ph
N
N
Ph
Ph
Ph
3x, 31%
3y, 52%
3z, 0%
aReactions were carried out under conditions as in Table 3. Isolated yields after column
chromatography are given.
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The experiments have shown that the reaction tolerates a series of aryl- and
hetarylacetylenes with donor and acceptor substituents in the benzene ring, the yields of the
corresponding azadienes 3p–y being 31-64% (Table 4). As seen, arylacetylenes are decorated with
a variety of different in chemical nature substituents such as methyl, phenyl, methoxy, and fluoro.
Hetarylacetylenes are 3-ethynylpyridine and 3-ethynylthiophene. It is important that most of the
above substrates (Tables 3, 4) contains substituents capable of feasible further transformations
(halogens, heterocycles) that allows to easily multiply the real substrate scope.
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In this case, the more pronounced is steric effect, which is likely the major cause of a lower
yield of acetylene 2d (R3 = 2,5-diMeC6H4). The reaction of aldimine 1a with tert-butylacetylene
2l does not give the expected product 3z both under the same conditions and at higher temperature
o
(30 C): only the starting compounds were almost completely recovered. Since acidity of tert-
butylacetylene is much lower than that of phenylacetylene (pKa=25.5 and 23.2, respectively),17 the
negative result here can be attributed to a small concentration of tert-butylethenyl anions in the
reaction mixture. Acetylenes with normal or secondary aliphatic substituents under the reaction
conditions are rapidly prototropically isomerized to allenes and internal acetylenes.
The irregularly variable yields of azadienes 3 (Tables 3, 4) appear to be indicative of the
fact that the overall process is a complex function of a number of parameters: electronic and steric
effects of the substituents in aldimine (both aldehyde and amine moieties) and acetylene, stability
of the starting aldimines 1 and the target azadienes 3 under the reaction conditions, particularly
propensity to condensation and addition reactions. Certainly, to reach a higher yield for each
aldimine/acetylene pair, an additional tuning of the reaction conditions is required.
According to the NMR data, in CDCl3 azadienes 3 are present as a mixture of 1E,2E- and
1Z,2E-isomers in ~ 3:1 ratio, except for 3i, which was obtained exclusively as 1E,2E-isomer (Table
3).
To verify scalability of the developed strategy, a gram-scale synthesis of azadiene 3l has
been implemented. Under the optimized conditions, aldimine 1l (5 mmol, 1 g) and acetylene 2a (5
mmol, 0.51 g) reacted smoothly to give 3l in 69% (1.04 g) isolated yield. This demonstrates a high
potential of this synthesis for large-scale application.
Apparently, the reaction represents an ordinary nucleophilic addition of the aldimine C-H
moiety to the triple bond, somewhat like the aldehyde C-H bond addition to the C=O bond, i.e.
benzoin condensation.
Alternatively, the reaction might be assumed to start (Scheme 2) with the deprotonation of
acetylene 2 under the action of superbase, and addition of acetylenic anion A to the C=N bond of
aldimine 1. Propargylamine B thus formed might undergo further prototropic isomerization to 1-
azadiene 3 via allenic intermediate C.
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Scheme 2. Tentative Scheme for 1-Azadienes 3 Formation
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R3
R3
-OBut
HOBut
-
2
A
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R3
R3
R3
R1
R1
HN
R3
R1
HN
R1
HOBut
-OBut
+
N
R2
N
R2
-
R2
R2
B
C
A
3
1
However, it is highly astonishing that none of the both intermediates (B and C) is detected
(1H NMR) in the reaction mixture though in trace amounts, even after a few minutes the reaction
started. Such extremely fast double prototropic isomerization of propargylamine B to allene C and,
further, to azadiene 3 under so low temperature (14 oC) looks very extraordinary.
To discriminate the two options, we have subjected separately synthesized intermediate B
(from benzaldehyde, aniline and phenylacetylene in the presence of CuCl2)18 to the reaction
conditions. What we have observed was lighting-like (just after the reactants mixing) quantitative
transformation of this propargylamine 4 to azadiene 3a (Scheme 3).
Scheme 3. Fast Isomerization of Propargylamine 4 to 1-Azadiene 3a
Ph
Ph
Ph
Ph
HN
KOBut/DMSO/THF
14 oC, 1-2 sec
N
Ph
Ph
4
3a
The result obtained is unambiguous evidence for the fast prototropic isomerization of
secondary propargylamines to 1-azadienes. Consequently, the synthesis here developed proceeds
via ethynylation of the C=N bond followed by the above rapid isomerization of the intermediates
B and C (Scheme 3). This unprecedented chemical transformation represents a self-standing value
both for synthetic and theoretical chemistry.
CONCLUSION
In summary, we have found and developed base-catalyzed transition metal-free C-H
vinylation of aldimines with aryl- and hetarylacetylenes opening a simple straightforward access
to synthetically valuable 1-azadienes of E configuration relative to the C-C bond in good yields.
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The reaction mechanism of this new Csp2-Csp2 bond forming reaction includes a nucleophilic
addition of acetylenes to the C=N bond with further unprecedentedly fast quantitative acetylene-
allene-azadiene isomerization. The reaction meets PASE19 requirements as being one-pot and
atom-economic in a one operation step. This together with availability of the starting materials and
catalytic system (without transition metals), mild reaction conditions, good scalability renders the
process technologically feasible. Despite a number of synthetic approaches to 1-azadienes, the
reaction allows synthesizing a novel family of these important intermediates.
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EXPERIMENTAL SECTION
1. General Remarks. 1Н (400.1 MHz), 13С (100.6 MHz), and 15N (40.5 MHz) NMR spectra were
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recorded on a Bruker AV400 instrument in СDCl3. The assignment of signals in the Н NMR
spectra was made using COSY and NOESY experiments. Resonance signals of carbon atoms were
assigned based on 1H-13C HSQC and 1H-13C HMBC experiments. The 1H and 13C chemical shifts
(δ) were referenced to hexamethyldisiloxane (0.05 ppm and 2.0 respectively). The chemical shifts
were recorded in ppm. Coupling constants (J) in hertz (Hz) were measured from one-dimensional
spectra and multiplicities were abbreviated as following: s (singlet), d (doublet), dd (doublet of
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doublets), m (multiplet). The values of the δ N were measured through the 2D H-15N HMBC
experiment. The 15N chemical shifts were referenced to CH3NO2. IR spectra were taken with FT-
IR. Melting points (uncorrected) were measured on a Kofler micro hot-stage apparatus. The
microanalyses were performed on a Flash EA 1112 Series elemental analyzer. Thin layer
chromatography was carried out on Merck silica gel 60 F254 pre-coated aluminium foil sheets
(eluent: hexane/diethyl ether = 1:3) and were visualized using UV light (254 nm). Column
chromatography was carried out using slurry packed Sigma Aldrich silica gel, 70-230 mesh, pore
size 60 Å (eluent: hexane/diethyl ether). Aldehydes, amines and all other chemicals and solvents
are commercially available and were used without further purification.
2. Starting Materials. Aldimines 1 were synthesized by published procedure from aldehydes and
amines.20 Propargylamine 4 was synthesized by A3 condensation from benzaldehyde,
phenylacetylene and aniline in the presence of CuCl2.18
3. Synthesis of 1-Azadienes 3 (general procedure). A mixture of aldimine 1 (1 mmol) in DMSO
(0.5 mL) was added dropwise to a mixture of acetylene 2 (1 mmol), KOBut (0.2 mmol, 22 mg),
THF (0.3 mL) in DMSO (3 mL) at 14 oC for 1 min. The resulting mixture was stirred at 14 oC for
1 h. Then, the reaction mixture was diluted with H2O (5 mL) and extracted with Et2O (1 mL × 7).
The organic extract was washed with H2O (1 mL × 3) and dried over MgSO4. Et2O was evaporated
under reduced pressure, and the residue was purified by column chromatography [SiO2, eluent:
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hexane/Et2O = 50 : 1 or 10 : 1 (for 3d,v), 1 : 1 (for 3x)]. Physical-chemical characteristics of 1-
azadiene 3a were identical to the literature data.6
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4. Rearrangement of Propargylamine 4 to 1-Azadiene 3a. A mixture of propargylamine 4 (1
mmol, 0.283 g) in DMSO (0.5 mL) was added in a mixture of KOBut (0.2 mmol, 22 mg), THF
(0.3 mL) in DMSO (3 mL) at 14 oC. Almost immediately (after 1-2 sec), the resulting mixture was
diluted with H2O (5 mL) and extracted with Et2O (1 mL × 7). The organic extract was washed
with H2O (1 mL × 3) and dried over MgSO4. Et2O was evaporated under reduced pressure. The
crude product is 1-azadiene 3a (0.271 mg, yield 96%).
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(2E)-N,1,3-Triphenylprop-2-en-1-imine (3a). Following the general procedure, 3a was prepared
from 1a (1 mmol, 0.181 g) and 2a (1 mmol, 0.102 g). 3a was isolated as a mixture of 1E,2E/1Z,2E-
isomers in a 3:1 molar ratio (0.204 g, 72% yield). Yellow solid; m.p.: 103-106 oC. Anal. Calcd for
C21H17N: C, 89.01; H, 6.05; N, 4.94. Found: C, 88.97; H, 6.11; N, 4.79. IR (film): νmax 3057, 3029,
2924, 2856, 1619, 1583, 1485, 1446, 1313, 1205, 1173, 1073, 1024, 975, 907, 862, 825, 754, 695.
1E,2E-3a. 1H NMR: δ 7.79-7.68 (m, 2H, Ho2), 7.52-7.47 (m, 3H, Hm2,p2), 7.41-7.38 (m, 2H, Hm1),
7.36-7.32 (m, 2H, Ho3), 7.32-7.30 (m, 3H, Hm3,p3), 7.18-7.13 (m, 1H, Hp1), 7.00-6.96 (m, 2H,
Ho1), 6.95 (d, 3J = 16.2 Hz, 1H, H3), 6.90 (d, 3J = 16.2 Hz, 1H, H2). 13C {1H} NMR: δ 167.2 (C1),
151.1 (Ci1), 141.7 (C3), 139.5 (Ci2), 135.8 (Ci3), 130.0 (Cp2), 129.5 (Cp3), 129.4 (Co2), 129.0
(Cm1), 128.9 (Cm3), 128.4 (Cm2), 127.6 (Co3), 124.0 (Cp1), 122.0 (C2), 120.9 (Co1). 15N NMR: δ
-49.7. 1Z,2E-3a. 1H NMR: δ 7.45-7.36 (m, 2H, Ho3), 7.32-7.29 (m, 6H, Hm2,p2,m3,p3), 7.30 (d, 3J
= 16.4 Hz, 1H, H2), 7.18-7.14 (m, 2H, Ho2), 7.14-7.09 (m, 2H, Hm1), 6.94-6.88 (m, 2H, Hp1), 6.85
(d, 3J = 16.4 Hz, 1H, H3), 6.71-6.67 (m, 2H, Ho1). 13C {1H} NMR: δ 169.0 (C1), 150.8 (Ci1), 141.4
(C3), 135.9 (Ci3), 135.6 (Ci2), 131.8 (C2), 129.3 (Cp3), 129.1 (Co2), 128.9 (Cm3), 128.5 (Cp2),
128.4 (Cm1), 128.1 (Cm2), 127.6 (Co3), 123.4 (Cp1), 121.1 (Co1). 15N NMR: δ -45.9.
(2E)-N,3-Diphenyl-1-(p-tolyl)prop-2-en-1-imine (3b). Following the general procedure, 3b was
prepared from 1b (1 mmol, 0.195 g) and 2a (1 mmol, 0.102 g). 3b was isolated as a mixture of
1E,2E/1Z,2E-isomers in a 3:1 molar ratio (0.181 g, 61% yield). Yellow solid; m.p.: 92-93 oC. Anal.
Calcd for C22H19N: C, 88.85; H, 6.44; N, 4.71. Found: C, 88.93; H, 6.35; N, 4.68. IR (film): νmax
3055, 3029, 2947, 2921, 2862, 1741, 1616, 1584, 1499, 1484, 1402, 1313, 1205, 1178, 1104, 1075,
1024, 976, 907, 856, 814, 759, 694. 1E,2E-3b. 1H NMR: δ 7.66-7.58 (m, 2H, Ho2), 7.37-7.29 (m,
2H, Hm1), 7.30-7.22 (m), 7.13-6.98 (m), 6.96-6.81 (m) [12H, H2,3,Ar], 2.42 (s, 3H, Me). 13C {1H}
NMR: δ 167.0 (C1), 151.3 (Ci1), 141.4 (C3), 140.2 (Cp2), 136.8, 136.0 (Ci2,i3), 129.5 (Cm2), 129.4
(Cp3), 129.2, 129.0, 128.9, (Co2,m1,m3), 127.6 (Co3), 123.9 (Cp1), 122.4 (C2), 121.0 (Co1), 21.5
(Me). 15N NMR: δ -53.2. 1Z,2E-3b. 1H NMR: δ 7.49-7.43 (m, 2H, Ho3), 7.37-7.21 (m), 7.13-6.98
(m), 6.96-6.81 (m) [12H, H2,3, Ar], 6.68-6.64 (m, 2H, Ho1), 2.29 (s, 3H, Me). 13C {1H} NMR: δ
169.0 (C1), 151.1 (Ci1), 141.2 (C3), 138.4 (Cp2), 136.1 (Ci3), 132.7 (Ci2), 132.1 (C2), 129.3 (Cp3),
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129.1, 128.9, 128.5 (Cm1,m2,m3,o2), 127.7 (Co3), 123.3 (Cp1), 121.2 (Co1), 21.5 (Me). 15N NMR:
δ -47.4.
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(2E)-1-(4-Methoxyphenyl)-N,3-diphenylprop-2-en-1-imine (3с). Following the general procedure,
3с was prepared from 1с (1 mmol, 0.211 g) and 2a (1 mmol, 0.102 g). 3c was isolated as a mixture
of 1E,2E/1Z,2E-isomers in a 7:2 molar ratio (0.219 g, 70% yield). Yellow solid; m.p.: 112-114 oC.
Anal. Calcd for C22H19NO: C, 84.31; H, 6.11; N, 4.47. Found: C, 84.42; H, 6.07; N, 4.24. IR (film):
νmax 3056, 3033, 2924, 2857, 1662, 1585, 1508, 1486, 1449, 1416, 1311, 1251, 1206, 1174, 1107,
1077, 1029, 977, 833, 761, 695. 1E,2E-3c. 1H NMR: δ 7.79-7.75 (m, 2H, Ho2), 7.41-7.36 (m, 2H,
Hm1), 7.38-7.36 (m, 2H, Hm1), 7.35-7.32 (m, 5H, Ho3,m3,p3), 7.15-7.13 (m, 1H, Hp1), 7.05-7.01
(m, 2H, Hm2), 7.01-6.97 (m, 2H, Ho1), 6.98 (d, 3J = 16.4 Hz, 1H, H3), 6.90 (d, 3J = 16.4 Hz, 1H,
H2), 3.91 (s, 3H, Me). 13C {1H} NMR: δ 166.4 (C1), 161.3 (Cp2), 151.3 (Ci1), 141.2 (C3), 135.9
(Ci3), 132.0 (Ci2), 131.1 (Co2), 129.4 (Cp3), 128.9 (Cm1,m3), 127.5 (Co3), 123.9 (Cp1), 122.5 (C2),
121.1 (Co1), 113.8 (Cm2), 55.5 (Me). 15N NMR: δ -55.8. 1Z,2E-3c. 1H NMR: δ 7.54-7.51 (m, 2H,
Ho3), 7.38-7.36 (m, 2H, Hm3), 7.35-7.32 (m, 1H, Hp3), 7.31 (d, 3J = 16.7 Hz, 1H, H2), 7.20-7.15
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(m, 2H, Hm1), 7.12-7.08 (m, 2H, Ho2), 6.94 (d, J = 16.7 Hz, 1H, H3), 6.95-6.93 (m, 1H, Hp1),
6.85-6.81 (m, 2H, Hm2), 6.74-6.70 (m, 2H, Ho1), 3.81 (s, 3H, Me). 13C {1H} NMR: δ 168.5 (C1),
159.64 (Cp2), 151.1 (Ci1), 141.1 (C3), 136.0 (Ci3), 132.0 (C2), 130.7 (Co2), 129.3 (Cp3), 128.9,
128.5 (Cm3,m1), 127.8 (Ci2), 127.6 (Co3), 123.3 (Cp1), 121.2 (Co1), 113.6 (Cm2), 55.3 (Me). 15N
NMR: δ -49.0.
(2E)-N,3-Diphenyl-1-(3,4,5-trimethoxyphenyl)prop-2-en-1-imine (3d). Following the general
procedure, 3d was prepared from 1d (1 mmol, 0.271 g) and 2a (1 mmol, 0.102 g). 3d was isolated
as a mixture of 1E,2E/1Z,2E-isomers in a 5:1 molar ratio (0.146 g, 39 % yield). Yellow oil. Anal.
Calcd for C24H23NO3: C, 77.19; H, 6.21; N, 3.75. Found: C, 77.36; H, 6.05; N, 3.28. IR (film):
νmax 3076, 3058, 2999, 2958, 2937, 2904, 2836, 1661, 1623, 1588, 1577, 1504, 1482, 1463, 1450,
1411, 1345, 1233, 1204, 1128, 1107, 1006, 786, 760, 699. 1E,2E-3d. 1H NMR: δ 7.39-7.27 (m),
7.16-7.09 (m), 7.01-6.92 (m) [13H, H3,Ar], 6.85 (d, 3J = 16.4 Hz, 1H, H2), 3.91 (s, 3H, p2-OMe),
3.89 (s, 6H, m2-OMe). 13C {1H} NMR: δ 166.8 (C1), 153.2 (Cm2), 151.0 (Ci1), 141.7 (C1), 141.2,
135.8, 134.9, 129.6 (4C, Ci2,p2,i3,p3), 129.0, 129.0, 127.6 (6C, Cm1,o3,m3), 124.1 (Cp1), 122.1
(C2), 121.0 (Co1), 106.9 (Co2), 61.1 (p2-OMe), 56.4 (m2-OMe). 1Z,2E-3d. 1H NMR: δ 7.53-7.48
(m), 7.39-7.19 (m), 7.15-7.10 (m), 7.04-6.90 (m), 6.70-6.65 (m) [12H, H2,3,Ar], 6.32 (s, 2H, Ho2),
3.83 (s, 3H, p2-OMe), 3.65 (s, 6H, m2-OMe).
(2E)-1-(4-Fluorophenyl)-N,3-diphenylprop-2-en-1-imine (3e). Following the general procedure,
3e was prepared from 1e (1 mmol, 0.199 g) and 2a (1 mmol, 0.102 g). 3e was isolated as a mixture
of 1E,2E/1Z,2E-isomers in a 2:1 molar ratio (0.184 g, 61% yield). Yellow solid; m.p.: 87-89 oC.
Anal. Calcd for C21H16FN: C, 83.70; H, 5.35; F, 6.30; N, 4.65. Found: C, 83.86; H, 5.21; F, 6.15;
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N, 4.32. IR (film): νmax 3060, 3033, 2955, 2923, 2855, 1741, 1581, 1505, 1485, 1450, 1401, 1311,
1225, 1157, 1087, 1074, 1020, 976, 837, 759, 694. 1E,2E-3e. 1H NMR: δ 7.78-7.73 (m, 2H, Ho2),
7.40-7.34 (m, 2H, Hm1), 7.33-7.30 (m, 5H, Ho3,m3,p3), 7.19-7.14 (m, 1H, Hp1), 7.01-6.89 (m, 5H,
H3,o1,m2), 6.83 (d, 3J = 16.4 Hz, 1H, H2). 13C {1H} NMR: δ 166.1 (C1), 164.1 (d, 1JCF = 249.6
Hz, Cp2), 151.0 (Hi1), 141.7 (H3), 135.7 (Hi3), 135.6 (d, 4JCF = 3.3 Hz, Ci2), 131.5 (d, 3JCF = 8.6
Hz, Co2), 129.7 (Cp3), 129.1 (Cm1), 129.0 (Cm3), 127.7 (Co3), 124.2 (Cp1), 122.1 (C2), 120.9
(Co1), 115.5 (d, 2JCF = 21.6 Hz, Cm2). 15N NMR: δ -51.0. 1Z,2E-3e. 1H NMR: δ 7.51-7.47 (m, 2H,
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Ho3), 7.40-7.29 (m), 7.20-7.10 (m), 7.06-6.85 (m) [12H, H2,3,Ar], 6.68-6.64 (m, 2H, Ho1). C
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{1H} NMR: δ 168.0 (C1), 162.6 (d, JCF = 248.6 Hz, Cp2), 150.8 (Ci1), 141.5 (C3), 135.8 (Ci3),
135.6 (d, 4JCF = 3.3 Hz, Ci2), 131.7 (C2), 131.1 (d, 3JCF = 8.1 Hz, Co2), 129.5 (Cp3), 129.0, 128.6,
127.7 (Cm3,m1,o3), 123.6 (Cp1), 121.1 (Co1), 115.4 (d, 2JCF = 21.6 Hz, Cm2). 15N NMR: δ -45.2.
(2E)-1-(4-Chlorophenyl)-N,3-diphenylprop-2-en-1-imine (3f). Following the general procedure,
3f was prepared from 1f (1 mmol, 0.216 g) and 2a (1 mmol, 0.102 g). 3f was isolated as a mixture
of 1E,2E/1Z,2E-isomers in a 3:1 molar ratio (0.159 g, 50% yield). Brown oil. Anal. Calcd for
C21H16ClN: C, 79.36; H, 5.07; Cl, 11.15; N, 4.41. Found: C, 79.43; H, 4.95; Cl, 11.02; N, 4.36. IR
(film): νmax 3086, 3056, 3035, 2980, 2925, 2856, 1618, 1588, 1494, 1437, 1370, 1313, 1208, 1161,
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1076, 1025, 977, 909, 825, 781, 750, 693. 1E,2E-3f. H NMR: δ 7.70-7.64 (m, 2H, Ho2), 7.48-
6.82 (m, 13H, H3,Ar), 6.78 (d, 3J = 16.6 Hz, 1H, H2). 13C {1H} NMR: δ 166.1 (C1), 150.8 (Ci1),
141.8 (C3), 137.9 (Ci2), 136.2 (Cp2), 135.6 (Ci3), 130.9 (Co2), 129.7 (Cp3), 129.0, 128.7
(Cm1,m2,m3), 127.6 (Co3), 124.3 (Cp1), 121.8 (C2), 120.8 (Co1). 15N NMR: δ -50.3. 1Z,2E-3f. 1H
NMR: δ 7.48-6.75 (m, 14H, H2,3,Ar), 6.65-6.60 (m, 2H, Ho1). 13C {1H} NMR: δ 167.8 (C1), 150.6
(Ci1), 141.6 (C3), 135.7 (Ci3), 134.6 (Ci2), 134.0 (Cp2), 131.5 (C2), 130.5 (Co2), 129.6 (Cp3),
129.0, 128.7, 128.6, 127.7 (Cm1,m2,m3,o3), 123.7 (Cp1), 121.0 (Co1). 15N NMR: δ -45.2.
(2E)-1-(4-Bromophenyl)-N,3-diphenylprop-2-en-1-imine (3g). Following the general procedure,
3g was prepared from 1g (1 mmol, 0.260 g) and 2a (1 mmol, 0.102 g). 3g was isolated as a mixture
of 1E,2E/1Z,2E-isomers in a 5:1 molar ratio (0.152 g, 42% yield). Brown oil. Anal. Calcd for
C21H16BrN: C, 69.63; H, 4.45; Br, 22.06; N, 3.87. Found: C, 69.76; H, 4.25; Br, 21.88; N, 3.54.
IR (film): νmax 3053, 3033, 3024, 2925, 2860, 1676, 1584, 1506, 1495, 1456, 1437, 1370, 1314,
1259, 1208, 1176, 1094, 1076, 976, 751, 697. 1E,2E-3g. 1H NMR: δ 7.61-7.58 (m, 2H, Ho2), 7.47-
6.87 (m, 13H, H3,Ar), 6.78 (d, 3J = 16.4 Hz, 1H, H2). 13C {1H} NMR: δ 166.1 (C1), 150.8 (Ci1),
141.8 (C3), 138.4 (Ci2), 135.6 (Ci3), 131.7, 131.1 (Co2,m2), 129.7 (Cp3), 129.0 (Cm1,m3), 127.6
(Co3), 124.5, 124.3 (Cp1,p2), 121.7 (C2), 120.8 (Co1). 1Z,2E-3g. 1H NMR: δ 7.47-6.81 (m, 14H,
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H2,3Ar), 6.65-6.61 (m, 2H, Ho1). C {1H} NMR: δ 167.7 (C1), 150.5 (Ci1), 141.6 (C3), 135.7,
134.5 (Ci2,i3), 132.0 (C2), 131.5, 130.7 (Co2,m2), 129.6 (Cp3), 129.0, 128.7, 127.7 (Cm1,m3,o3),
123.7, 122.9 (Cp1,p2), 121.0 (Co1).
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(2E)-1-(Furan-2-yl)-N,3-diphenylprop-2-en-1-imine (3h). Following the general procedure, 3h
was prepared from 1h (1 mmol, 0.171 g) and 2a (1 mmol, 0.102 g). 3h was isolated as a mixture
of 1E,2E/1Z,2E-isomers in a 4:1 molar ratio (0.153 g, 56% yield). Yellow oil. Anal. Calcd for
C19H15NO: C, 83.49; H, 5.53; N, 5.12. Found: C, 83.61; H, 5.38; N, 4.95. IR (film): νmax 3134,
3109, 3059, 3027, 2958, 2926, 2857, 1629, 1581, 1478, 1453, 1389, 1313, 1233, 1204, 1162, 1094,
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1069, 1019, 975, 913, 882, 821, 754, 695. 1E,2E-3h. H NMR: δ 7.61-7.58 (m, 1H, H5'), 7.48-
6.77 (m, 12H, H3,Ph,3'), 6.74 (d, 3J = 16.4 Hz, 1H, H2), 6.57-6.53 (m, 1H, H4'). 13C {1H} NMR:
δ 155.5 (C1), 152.5 (C2'), 150.2 (Ci1), 145.0 (C5'), 140.0 (C3), 135.7 (Ci3), 129.4 (Cp3), 128.9,
128.8, 127.4 (Cm1,m3,o3), 124.2 (Cp1), 121.3 (Co1), 118.7 (C2), 114.9 (C4'), 111.7 (C3'). 15N
NMR: δ -63.5. 1Z,2E-3h. H NMR: δ 7.61-7.58 (m, 1H, H5'), 7.2-7.58 (m, 2H, Ho3), 7.47-6.54
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(m, 12H, H3,Ph,3',4'). 13C {1H} NMR: δ 153.5 (C1), 152.6 (C2'), 148.2 (Ci1), 143.0 (C5'), 138.2
(C3), 136.2 (Ci3), 130.6 (C2), 129.3 (Cp3), 128.8, 128.6, 127.7 (Cm1,m3,o3), 123.4 (Cp1), 121.2
(Co1), 115.8 (C4'), 112.6 (C3'). 15N NMR: δ -61.3.
(1E,2E)-N,3-Diphenyl-1-(thiophen-2-yl)prop-2-en-1-imine (3i). Following the general procedure,
3i was prepared from 1i (1 mmol, 0.187 g) and 2a (1 mmol, 0.102 g). 3i was isolated as a yellow
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solid (0.168 g, 58% yield). M.p.: 102-103 C. Anal. Calcd for C19H15NS: C, 78.86; H, 5.22; N,
4.84; S, 11.08. Found: C, 78.92; H, 5.17; N, 4.72; S, 11.13. IR (film): νmax 3064, 3027, 2955, 2922,
2851, 1625, 1568, 1483, 1425, 1357, 1326, 1297, 1200, 1166, 1063, 1014, 975, 907, 849, 818,
781, 757, 696. 1H NMR: δ 7.60 (dd, 3J = 3.7 Hz, 4J = 1.2 Hz, 1H, H3'), 7.56 (dd, 3J = 5.1 Hz, 4J =
1.2 Hz, 1H, H5'), 7.41-7.37 (m, 2H, Ho2), 7.39-7.35 (m, 2H, Hm1), 7.35-7.33 (m, 3H, Hm2,p2),
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7.29 (d, J = 16.5 Hz, 1H, H3), 7.56 (dd, J = 5.1 Hz, J = 3.7 Hz, 1H, H4'), 7.17-7.10 (m, 1H,
Hp1), 7.01-6.95 (m, 2H, Ho1), 6.86 (d, 3J = 16.5 Hz, 1H, H2). 13C {1H} NMR: δ 159.9 (C1), 150.3
(Ci1), 144.5 (C2'), 140.2 (C3), 135.7 (C3'), 130.0 (Ci3), 129.7 (C3'), 129.4 (C5'), 128.9, 127.4
(Cp3,m1,m3,4'), 124.2 (Cp1), 122.1 (C2), 121.3 (Co1). 15N NMR: δ -59.8.
(2E)-1,3-Diphenyl-N-(o-tolyl)prop-2-en-1-imine (3j). Following the general procedure, 3j was
prepared from 1j (1 mmol, 0.195 g) and 2a (1 mmol, 0.102 g). 3j was isolated as a mixture of
1E,2E/1Z,2E-isomers in a 4:1 molar ratio (0.175 g, 59% yield). Yellow oil. Anal. Calcd for
C22H19N: C, 88.85; H, 6.44; N, 4.71. Found: C, 88.76; H, 6.39; N, 4.78. IR (film): νmax 3059, 3028,
2973, 2923, 2856, 1617, 1588, 1485, 1449, 1379, 1313, 1213, 1185, 1108, 1077, 1032, 977, 911,
863, 839, 797, 750, 696. 1E,2E-3j. 1H NMR: δ 7.81-7.72 (m, 2H, Ho2), 7.57-7.45 (m), 7.42-7.18
(m), 7.16-7.04 (m) [11H, H2,Ar], 6.97 (d, 3J = 16.5 Hz, 1H, H3), 6.99-6.75 (m, 2H, Ar), 2.19 (s,
3H, Me). 13C {1H} NMR: δ 166.8 (C1), 149.9 (C1'), 141.6 (C3), 139.3 (Ci2), 135.8 (Ci3), 130.5,
129.9, 129.5, 129.3, 128.9, 128.4, 127.6, 126.4, 123.8 [14C, Ar], 121.7 (C2), 119.3 (C6'), 18.1
(Me). 15N NMR: δ -48.1. 1Z,2E-3j. 1H NMR: δ 7.57-7.45 (m), 7.42-7.18 (m), 7.16-7.04 (m), 6.99-
6.75 (m) [16H, H2,3,Ar], 2.23 (s, 3H, Me). 13C {1H} NMR: δ 168.3 (C1), 149.9 (C1'), 141.1 (C3),
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136.0, 135.9 (Ci2,i3), 131.6 (C2), 130.0, 129.3, 128.9, 128.5, 128.1, 125.8, 123.3, 119.7 [15C,
CAr], 18.3 (Me). 15N NMR: δ -44.4.
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(2E)-N-(3-Methoxyphenyl)-1,3-diphenylprop-2-en-1-imine (3k). Following the general procedure,
3k was prepared from 1k (1 mmol, 0.211 g) and 2a (1 mmol, 0.102 g). 3k was isolated as a mixture
of 1E,2E/1Z,2E-isomers in a 3:1 molar ratio (0.182 g, 58 % yield). Yellow oil. Anal. Calcd for
C22H19NO: C, 84.31; H, 6.11; N, 4.47. Found: C, 84.19; H, 6.23; N, 4.26. IR (film): νmax 3099,
3079, 3058, 3025, 3001, 2955, 2937, 2913, 2833, 1613, 1589, 1482, 1447, 1316, 1281, 1259, 1146,
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1074, 1043, 974, 939, 870, 853, 762, 754, 697. 1E,2E-3k. H NMR: δ 7.75-7.67 (m, 2H, Ho2),
7.51-7.41 (m), 7.35-7.22 (m), 6.93-6.88 (m), 6.55-6.49 (m) [14H, H2,3,Ar], 3.79 (s, 3H, OMe).
13C {1H} NMR: δ 167.3 (C1), 160.4 (C3'), 152.4 (Ci1), 141.8 (C3), 139.4 (Ci2), 135.8 (Ci3), 130.0,
129.8, 129.5, 128.9, 128.5, 127.7 (11C, CAr), 122.1 (C3), 113.1, 110.1, 106.3 (3C, C2',4',6'), 55.4
(OMe). 1Z,2E-3k. 1H NMR: δ 7.49-7.44 (m), 7.33-7.21 (m), 7.18-7.09 (m) [12H, H2,Ar], 6.98 (d,
3J = 16.4 Hz, H3), 6.47-6.43 (m), 6.26-6.20 (m) [3H, HAr], 3.63 (s, 3H, OMe). 13C {1H} NMR: δ
169.1 (C1), 159.8 (C3'), 153.3 (Ci1), 141.6 (C3), 131.7, 129.2, 129.0, 128.9, 128.6, 128.2, 127.7,
113.8, 109.6, 106.7 (17C, C2,Ar), 55.2 (OMe).
(2E)-N-(2-Fluorophenyl)-1,3-diphenylprop-2-en-1-imine (3l). Following the general procedure, 3l
was prepared from 1l (1 mmol, 0.199 g) and 2a (1 mmol, 0.102 g). 3l was isolated as a mixture of
1E,2E/1Z,2E-isomers in a 2:1 molar ratio (0.193 g, 64% yield). Yellow oil. Anal. Calcd for
C21H16FN: C, 83.70; H, 5.35; F, 6.30; N, 4.65. Found: C, 83.96; H, 5.21; F, 6.19; N, 4.59. IR
(film): νmax 3146, 3059, 3032, 2958, 2924, 2855, 1662, 1595, 1487, 1448, 1317, 1233, 1186, 1100,
1080, 1027, 976, 911, 865, 842, 752, 697. 1E,2E-3l. 1H NMR: 7.79-7.72 (m, 2H, Ho2), 7.51-7.42
(m, 3H, Hm2,p2), 7.36-7.22 (m), 7.17-7.05 (m), 7.01-6.92 (m), 6.88-6.980 (m), 6.67-6.58 (m) [11H,
H2,3,Ar]. 13C {1H} NMR: δ 169.4 (C1), 152.7 (d, 1JCF = 245.7 Hz, C2'), 142.4 (C3), 138.9 (Ci2),
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138.7 (d, JCF = 12.5 Hz, C1'), 135.6 (Ci3), 130.2, 129.7 (Cp2,p3), 129.5, 128.6, 128.4, 127.6
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(Co2,o3,m2,m3), 125.0 (d, JCF = 7.2 Hz, C4'), 124.3 (d, JCF = 3.8 Hz, C6'), 122.8 (d, JCF = 2.3
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Hz, C5'), 121.6 (C2), 116.1 (d, JCF = 19.8 Hz, C3'). 1Z,2E-3l. H NMR: 7.851-7.24 (m), 7.16-
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7.04 (m), 7.00-6.78 (m) [11H, H2,3,Ar], 6.67-6.00 (m, 1H, C3'). C {1H} NMR: δ 171.8 (C1),
152.5 (d, 1JCF = 244.3 Hz, C2'), 142.3 (C3), 139.1 (d, 2JCF = 12.4 Hz, C1'), 135.7 (Ci2,i3), 131.12
(C2), 129.5 (Cp3), 128.9 (Cm3), 128.8 (Cp2), 128.3, 128.1, 127.7 (Co2,m2,o3), 124.4 (d, 3JCF = 7.3
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Hz, C4'), 123.8 (d, JCF = 3.6 Hz, C6'), 122.6 (d, JCF = 2.3 Hz, C5'), 115.6 (d, JCF = 20.2 Hz,
C3').
(2E)-N-(2-Bromophenyl)-1,3-diphenylprop-2-en-1-imine (3m). Following the general procedure,
3m was prepared from 1m (1 mmol, 0.260 g) and 2a (1 mmol, 0.102 g). 3m was isolated as a
mixture of 1E,2E/1Z,2E-isomers in a 2:1 molar ratio (0.120 g, 33% yield). Yellow oil. Anal. Calcd
for C21H16BrN: C, 69.63; H, 4.45; Br, 22.06; N, 3.87. Found: C, 69.89; H, 4.31; Br, 22.12; N, 3.64.
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IR (film): νmax 3058, 3033, 2954, 2923, 2854, 1676, 1586, 14519, 1797, 1455, 1443, 1314, 1258,
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1210, 1180, 10941075, 1026, 976, 912, 859, 752, 696. 1E,2E-3m. H NMR: 7.82-7.74 (m, 2H,
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Ho2), 7.65-7.07 (m), 7.01-6.81 (m), 6.78-6.65 (m) [14H, H2,3,Ar]. 13C {1H} NMR: δ 168.5 (C1),
149.6 (C2'), 142.7 (C3), 138.7, 135.7 (Ci2,Ci3), 133.1 (CAr), 130.2 (Cp2), 129.8 (Cp3), 129.5,
128.9, 128.5 (Co2,m2,m3), 128.1 (CAr), 127.8 (Co3), 124.9 (CAr), 121.5 (C2), 121.1, 114.6 (2C,
CAr). 1Z,2E-3m. 1H NMR: 8.03-7.96 (m), 7.94-7.87 (m), 7.65-7.07 (m), 7.01-6.81 (m), 6.78-6.65
(m), 6.45-6.40 (m) [16H, H2,3,Ar]. 13C {1H} NMR: δ 170.2 (C1), 150.0 (C2'), 142.6 (C3), 135.8,
135.4 (Ci2,i3), 132.4 (CAr), 131.0 (C2), 129.6 (Cp3), 128.9 (Cm3), 128.9 (Cp2), 128.4, 128.1, 127.8
(Co2,m2,o3), 127.5, 124.4, 121.4, 115.5 (4C, CAr).
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(2E)-N-(Naphthalen-1-yl)-1,3-diphenylprop-2-en-1-imine (3n). Following the general procedure,
3n was prepared from 1n (1 mmol, 0.231 g) and 2a (1 mmol, 0.102 g). 3n was isolated as a mixture
of 1E,2E/1Z,2E-isomers in a 3:1 molar ratio (0.143 g, 43% yield). Yellow oil. Anal. Calcd for
C25H19N: C, 90.06; H, 5.74; N, 4.20. Found: C, 90.32; H, 5.51; N, 4.15. IR (film): νmax 3053, 2922,
2854, 2257, 1615, 1571, 1498, 1446, 1389, 1311, 1266, 1218, 1175, 1155, 1097, 1073, 1019, 974,
908, 871, 778, 732, 695. 1E,2E-3n. 1H NMR: δ 7.94-7.88 (m, 1H, HNaphth), 7.87-7.80 (m, 2H,
Ho2), 7.64-7.58 (m, 1H, HNaphth), 7.54-7.27 (m), 7.24-7.02 (m), 6.99-6.75 (m) [15H, H2,3,Ar].
13C {1H} NMR: δ 167.9 (C1), 147.7 (C1'), 142.0 (C3), 139.4, 135.7 (Ci2,i3), 134.3, 130.1, 129.6,
129.5, 128.8, 128.5, 128.0, 127.6, 126.4, 125.9, 125.6, 124.2, 124.0 (18C, CAr), 122.1 (C2), 114.6
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(CNaphth). 1Z,2E-3n. H NMR: δ 8.07-8.03 (m), 7.76-7.71 (m) [2H, HNaphth], 7.54-7.27 (m),
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7.24-7.02 (m), 6.99-6.75 (m) [16H, H2,3,Ar], 6.40-6.36 (m, 1H, HNaphth). C {1H} NMR: δ
169.7 (C1), 141.6 (C3), 136.0, 135.7 (Ci2,i3), 133.9, 131.7, 130.1, 129.5, 129.0, 128.6, 128.5,
128.4, 128.0, 127.9, 127.7, 126.9, 126.1, 125.6, 123.4, 114.7 (21C, C2, CAr).
(2E)-N,1-Diphenyl-3-(m-tolyl)prop-2-en-1-imine (3p). Following the general procedure, 3p was
prepared from 1a (1 mmol, 0.181 g) and 2b (1 mmol, 0.116 g). 3p was isolated as a mixture of
1E,2E/1Z,2E-isomers in a 5:2 molar ratio (0.191 g, 64 % yield). Yellow oil. Anal. Calcd for
C22H19N: C, 88.85; H, 6.44; N, 4.71. Found: C, 88.72; H, 6.88; N, 4.56. IR (film): νmax 3057, 3027,
2950, 2920, 2860, 1622, 1602, 1587, 1573, 1482, 1445, 1318, 1305, 1278, 1233, 1207, 1168, 1085,
1073, 1026, 978, 907, 835, 781, 770, 739, 697, 660. 1E,2E-3p. 1H NMR: δ 7.76-7.68 (m, 2H, Ho2),
7.49-7.41 (m), 7.37-7.32 (m), 7.29-7.05 (m), 6.96-6.92 (m), 6.90-6.86 (m) [14H, H2,3,Ar], 2.28
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(s, 3H, Me). C {1H} NMR: δ 167.3 (C1), 151.1 (Ci1), 142.0 (C3), 139.6, 138.6, 135.8, 130.4,
130.0, 129.5, 129.0, 128.8, 128.4, 124.6, 124.0 (15C, CAr), 121.9 (C2), 120.9 (Co1), 21.4 (Me).
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1Z,2E-3p. H NMR: δ 7.49-7.41 (m), 7.30-7.05 (m), 6.90-6.84 (m) [13H, H2, Ar], 6.79 (d, J =
16.3 Hz, 1H, H3), 6.67-6.62 (m, 2H, Ho1), 2.32 (s, 3H, Me). 13C {1H} NMR: δ 169.1 (C1), 150.9
(Ci1), 141.6 (C3), 138.45, 135.9, 135.7, 131.7, 130.2, 129.1, 128.5, 128.4, 128.1, 124.7, 123.4
(16C, C2,Ar) 121.2 (Co1), 21.5 (Me).
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(2E)-N,1-Diphenyl-3-(p-tolyl)prop-2-en-1-imine (3q). Following the general procedure, 3q was
prepared from 1a (1 mmol, 0.181 g) and 2c (1 mmol, 0.116 g). 3q was isolated as a mixture of
1E,2E/1Z,2E-isomers in a 3:1 molar ratio (0.158 g, 53% yield). Light yellow solid; m.p.: 87-89
oC. Anal. Calcd for C22H19N: C, 88.85; H, 6.44; N, 4.71. Found: C, 88.77; H, 6.48; N, 4.63. IR
(film): νmax 3052, 3028, 2921, 2866, 1583, 1508, 1484, 1446, 1315, 1206, 1180, 1076, 1025, 977,
909, 812, 767, 736, 699. 1E,2E-3q. 1H NMR: δ 7.81-7.75 (m, 2H, Ho2), 7.55-7.47 (m, 3H, Hm2,p2),
7.44-7.37 (m), 7.25-7.22 (m) [4H, Ho3,m1), 7.18-7.14 (m, 1H, Hp1), 7.16-7.11 (m), 7.03-7.99 (m)
[4H, Hm3,o1), 6.94 (d, 3J = 18.3 Hz, 1H, H3), 6.89 (d, 3J = 18.3 Hz, 1H, H2), 2.36 (s, 3H, Me). 13C
{1H} NMR: δ 167.4 (C1), 151.2 (Ci1), 141.8 (C3), 139.8 (Ci2), 139.6 (Cp3), 133.1 (Ci3), 129.9
(Cp2), 129.6, 129.5, 128.9, 128.4, 127.6 (Cm1,m2,m3,o2,o3), 123.9 (Cp1), 121.1 (C2), 120.9 (Co1),
21.5 (Me). 15N NMR: δ -52.8. 1Z,2E-3q. 1H NMR: δ 7.44-7.37 (m, 2H, Ho3), 7.33-7.28 (m, 3H,
Hm2,p2), 7.29 (d, 3J = 16.2 Hz, 1H, H2), 7.21-7.12 (m, 6H, Hm1,m3,o2), 6.94-6.92 (m, 1H, Hp1),
6.85 (d, 3J = 16.2 Hz, 1H, H3), 6.74-6.69 (m, 2H, Ho1), 2.39 (s, 3H, Me). 13C {1H} NMR: δ 169.12
(C1), 150.9 (Ci1), 141.5 (C3), 139.6 (Cp3), 135.7, 133.2 (Ci2,Ci3), 130.8 (C2), 129.6, 129.1
(Cm3,o2), 128.5 (Cp2), 128.4, 128.1, 127.6 (Cm1,m2,o3), 123.3 (Cp1), 121.2 (Co1), 21.5 (Me). 15N
NMR: δ -49.0.
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(2E)-3-(2,5-Dimethylphenyl)-N,1-diphenylprop-2-en-1-imine (3r). Following the general
procedure, 3r was prepared from 1a (1 mmol, 0.181 g) and 2d (1 mmol, 0.130 g). 3r was isolated
as a mixture of 1E,2E/1Z,2E-isomers in a 3:1 molar ratio (0.097 g, 31% yield). Yellow oil. Anal.
Calcd for C23H21N: C, 88.71; H, 6.80; N, 4.50. Found: C, 88.84; H, 6.71; N, 4.44. IR (film): νmax
3056, 3025, 2957, 2922, 2864, 1658, 1587, 1489, 1447, 1381, 1312, 1255, 1208, 1165, 1129, 1064,
977, 844, 812, 763, 697. 1E,2E-3r. 1H NMR: δ 7.79-7.73 (m, 2H, Ho2), 7.49-7.43 (m, 3H, Hm2,p2),
7.38-7.31 (m, 2H, Hm1), 7.28-7.22 (m), 7.19-7.05 (m), 7.04-6.85 (m), 6.79-6.71 (m) [8H, H2,3,Ar],
2.24 (s, 3H, Me), 2.15 (s, 3H, Me). 13C {1H} NMR: δ 167.4 (C1), 151.2 (Ci1), 140.0 (Ci2), 139.7
(C3), 135.8, 134.7, 133.9, 130.6, 130.1, 130.0 [6C, Cp2,Ar], 129.5, 129.0, 128.4 (Co2,m1,m2), 124.0
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(Cp1), 126.7 (CAr), 123.1 (C2), 120.9 (Co1), 21.1 (Me), 19.3 (Me). 1Z,2E-3r. H NMR: δ 7.38-
7.31 (m), 7.28-7.22 (m), 7.19-7.05 (m), 7.04-6.85 (m), 6.79-6.71 (m) [13H, H2,3,Ar], 6.68-6.64
(m, 2H, Ho1), 2.32 (s, 3H, Me), 2.15 (s, 3H, Me). 13C {1H} NMR: δ 169.2 (C1), 150.9 (Ci1), 139.5
(C3), 135.8, 134.7, 133.9 (4C, Ci2,Ar), 132.6 (C2), 130.6, 130.0 (2C, CAr), 129.1 (Co2), 128.5,
128.1 (Cp2,m1,m2), 126.8 (CAr), 123.4 (Cp1), 121.2 (Co1), 21.1 (Me), 19.2 (Me).
(2E)-3-([1,1'-Biphenyl]-4-yl)-N,1-diphenylprop-2-en-1-imine (3s). Following the general
procedure, 3s was prepared from 1a (1 mmol, 0.181 g) and 2e (1 mmol, 0.178 g). 3s was isolated
as a mixture of 1E,2E/1Z,2E-isomers in a 5:2 molar ratio (0.155 g, 43% yield). Brown oil. Anal.
Calcd for C27H21N: C, 90.21; H, 5.89; N, 3.90. Found: C, 90.58; H, 5.75; N, 3.62. IR (film): νmax
3056, 3029, 2958, 2924, 2857, 1658, 1618, 1584, 1483, 1447, 1405, 1316, 1208, 1177, 1102, 1075,
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1016, 977, 908, 831, 762, 696. 1E,2E-3s. 1H NMR: δ 7.77-7.72 (m, 2H, Ho2), 7.66-7.31 (m), 7.29-
7.21 (m), 7.15-7.06 (m), 6.99-6.82 (m) [19H, H2,3,Ar]. 13C {1H} NMR: δ 167.1 (C1), 151.2 (Ci1),
142.2 (CAr), 141.2 (C3), 140.3, 139.5 [2C, CAr], 135.7 (Ci2), 134.8 (CAr), 130.0 (Cp2), 129.5,
129.0, 128.9, 128.4, 128.0, 127.5, 127.0 [14C, CAr], 124.0 (Cp1), 122.0 (C2), 120.9 (Co1). 1Z,2E-
3s. 1H NMR: δ 7.66-7.31 (m), 7.29-7.21 (m), 7.15-7.06 (m), 6.99-6.82 (m) [19H, H2,3,Ar], 6.68-
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6.63 (m, 2H, Ho1). C {1H} NMR: δ 168.9 (C1), 150.9 (Ci1), 142.0 (CAr), 140.8 (C3), 140.4,
135.0 [2C, CAr], 131.8 (C2), 129.0, 128.7, 128.6, 128.5, 128.1, 127.8, 127.7, 127.7, 127.1 [17C,
CAr], 123.4 (Cp1), 121.2 (Co1).
(2E)-3-(3-Methoxyphenyl)-N,1-diphenylprop-2-en-1-imine (3t). Following the general procedure,
3t was prepared from 1a (1 mmol, 0.181 g) and 2f (1 mmol, 0.132 g). 3t was isolated as a mixture
of 1E,2E/1Z,2E-isomers in a 5:2 molar ratio (0.135 g, 43% yield). Yellow oil. Anal. Calcd for
C22H19NO: C, 84.31; H, 6.11; N, 4.47. Found: C, 84.42; H, 6.25; N, 4.23. IR (film): νmax 3057,
3027, 2950, 2933, 2837, 1662, 1587, 1485, 1452, 1313, 1282, 1247, 1210, 1162, 1076, 1044, 976,
908, 842, 773, 696. 1E,2E-3t. H NMR: δ 7.74-7.69 (m, 2H, Ho2), 7.49-7.42 (m, 3H, Hm2,p2),
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7.37-7.30 (m, 2H, Hm1), 7.28-6.98 (m), 6.97-6.74 (m) [9H, H2,3,Ar], 3.73 (s, 3H, OMe). 13C {1H}
NMR: δ 167.0 (C1), 160.0 (Ci1), 151.1 (C3'), 141.5 (C3), 139.5, 137.2 (Ci2,1'), 130.0 (Cp2), 129.9
(C5'), 129.4, 128.9, 128.4 (Co2,m1,m2), 124.0 (Cp1), 122.4 (C2), 120.8 (Co1), 120.1 (C6'), 115.6,
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113.0 (2C, C2',4'), 55.3 (OMe). 1Z,2E-3t. H NMR: δ 7.28-6.98 (m), 6.97-6.74 (m) [14H,
H2,3,Ar], 7.67-7.62 (m, 2H, Ho1), 3.78 (s, 3H, Me). C {1H} NMR: δ 168.9 (C1), 160.0 (Ci1),
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150.8 (C3'), 141.3 (C3), 137.3, 135.6 (C1',i2), 132.1 (C2), 129.8 (C5'), 129.0 (Co2), 128.5 (Cp2),
128.4, 128.1 (Cm1,m2), 123.4 (Cp1), 121.1 (Co1), 120.5 (C6'), 115.0, 112.1 (2C, C2',4'), 55.3
(OMe).
(2E)-3-(4-Methoxyphenyl)-N,1-diphenylprop-2-en-1-imine (3u). Following the general procedure,
3u was prepared from 1a (1 mmol, 0.181 g) and 2g (1 mmol, 0.132 g). 3u was isolated as a mixture
of 1E,2E/1Z,2E-isomers in a 3:1 molar ratio (0.197 g, 63 % yield). Yellow solid; m.p.: 88-90 oC.
Anal. Calcd for C22H19NO: C, 84.31; H, 6.11; N, 4.47. Found: C, 84.41; H, 6.18; N, 4.32. IR (film):
νmax 3058, 3030, 3013, 2957, 2934, 2909, 2836, 1603, 1586, 1573, 1511, 1482, 1443, 1421, 1319,
1307, 1253, 1207, 1174, 1085, 1073, 1028, 976, 908, 827, 793, 762, 732, 698. 1E,2E-3u. 1H NMR:
δ 7.74-7.67 (m, 2H, Ho2), 7.50-7.30 (m), 7.27-7.20 (m), 7.14-7.05 (m), 6.97-6.92 (m), 6.89-6.71
(m) [14H, H2,3,Ar], 3.78 (s, 3H, OMe). 13C {1H} NMR: δ 167.5 (C1), 160.8 (Ci1), 151.3 (Cp3),
141.5 (C3), 139.7, 129.8, 129.4, 129.1, 128.9, 128.4, 123.8, 120.9 (15C, C2,Ar), 114.3 (Cm3), 55.4
(OMe). 1Z,2E-3u. 1H NMR: δ 7.50-7.38 (m), 7.27-7.20 (m), 7.14-7.05 (m), 6.89-6.71 (m) [14H,
H2,3,Ar], 6.67-6.61 (m, 2H, Ho1), 3.81 (s, 3H, Me). C {1H} NMR: δ 169.2 (C1), 160.7 (Ci1),
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151.0 (Cp3), 141.1 (C3), 135.8, 129.7, 129.1, 128.7, 128.5, 128.4, 128.1, 123.2, 121.2, 119.9 (17C,
C2,Ar), 55.4 (OMe).
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(2E)-3-(3-Fluorophenyl)-N,1-diphenylprop-2-en-1-imine (3v). Following the general procedure,
3v was prepared from 1a (1 mmol, 0.181 g) and 2h (1 mmol, 0.120 g). 3v was isolated as a mixture
of 1E,2E/1Z,2E-isomers in a 2:1 molar ratio (0.181 g, 60% yield). Yellow solid; m.p.: 81-83 oC.
Anal. Calcd for C21H16FN: C, 83.70; H, 5.35; F, 6.36; N, 4.65. Found: C, 83.77; H, 5.42; F, 6.23;
N, 4.57. IR (film): νmax 3061, 3033, 2924, 2875, 1665, 1585, 1486, 1444, 1312, 1274, 1234, 1214,
1146, 1076, 1023, 973, 908, 856, 778, 735, 697. 1E,2E-3v. 1H NMR: δ 7.74-7.68 (m, 2H, Ho2),
7.50-7.43 (m, 3H, Hm2,p2), 7.39-7.21 (m), 7.18-6.85 (m) [11H, H2,3,Ar]. 13C {1H} NMR: δ 166.7
(C1), 163.1 (d, 1JCF = 246.6 Hz, C3'), 150.9 (Ci1), 140.2 (d, 4JCF = 2.1 Hz, C3), 139.3 (Ci2), 138.1
(d, 3JCF = 7.7 Hz, C1'), 130.4 (d, 3JCF = 8.1 Hz, C5'), 130.1 (Cp2), 129.4, 129.0, 128.5 (Co2,m1,m2),
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124.2 (Cp1), 123.4 (d, JCF = 2.8 Hz, C6'), 123.2 (C2), 120.8 (Co1), 116.3 (d, JCF = 21.3 Hz),
113.9 (d, 2JCF = 21.8 Hz) [2C, C2',4']. 1Z,2E-3v. 1H NMR: δ 7.52-7.42 (m), 7.39-7.21 (m), 7.18-
6.85 (m) [14H, H2,3,Ar], 6.78 (d, 1H, 3J = 16.3 Hz, H3), 6.61-6.62 (m, 2H, Ho1). 13C {1H} NMR:
δ 168.5 (C1), 164.4 (d, 1JCF = 246.6 Hz, C3'), 150.7 (Ci1), 139.8 (d, 4JCF = 1.0 Hz, C3), 138.3 (d,
3JCF = 7.7 Hz, C1'), 135.5 (Ci2), 133.1 (C2), 130.3 (d, 3JCF = 7.9 Hz, C5'), 129.0 (Co2), 128.6 (Cp2),
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128.5, 128.2 (Cm1,m2), 123.6 (Cp1), 123.3 (d, JCF = 1.2 Hz, C6'), 121.1 (Co1), 116.1 (d, JCF
=
21.2 Hz), 114.0 (d, 2JCF = 21.8 Hz) [C2',4'].
(2E)-3-(4-Fluorophenyl)-N,1-diphenylprop-2-en-1-imine (3w). Following the general procedure,
3w was prepared from 1a (1 mmol, 0.181 g) and 2i (1 mmol, 0.120 g). 3w was isolated as a mixture
of 1E,2E/1Z,2E-isomers in a 5:2 molar ratio (0.169 g, 56% yield). Yellow solid; m.p.: 76-79 oC.
Anal. Calcd for C21H16FN: C, 83.70; H, 5.35; F, 6.36; N, 4.65. Found: C, 83.86; H, 5.48; F, 6.12;
N, 4.49. IR (film): νmax 3058, 2925, 2871, 1662, 1591, 1506, 1483, 1446, 1413, 1314, 1230, 1160,
1093, 1076, 1020, 977, 908, 830, 765, 697. 1E,2E-3w. 1H NMR: δ 7.72-7.68 (m, 2H, Ho2), 7.52-
7.39 (m, 3H, Hm2,p2), 7.39-7.32 (m, 2H, Hm1), 7.29-7.21 (m), 7.15-6.80 (m) [9H, H2,3,Ar]. 13C
{1H} NMR: δ 167.0 (C1), 163.5 (d, 1JCF = 250.3 Hz, Cp3), 151.1 (Ci1), 140.4 (d, 5JCF = 1.0 Hz,
C3), 139.4 (Ci2), 132.0 (d, 4JCF = 3.4 Hz, Ci3), 130.0 (Cp2), 129.4 (Co2), 129.3 (d, 3JCF = 8.3 Hz,
Co3), 129.0, 128.5 (Cm1,m2), 124.1 (Cp1), 120.8 (C2,o1), 116.0 (d, 2JCF = 21.9 Hz, Cm3). 15N NMR:
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δ -50.3. 1Z,2E-3w. H NMR: δ 7.65-7.39 (m), 7.21-6.74 (m) [14H, H2,3,Ar], 6.61-6.62 (m, 2H,
Ho1). 13C {1H} NMR: δ 168.8 (C1), 163.4 (d, 1JCF = 249.9 Hz, Cp3), 150.8 (Ci1), 140.0 (d, 5JCF
=
1.0 Hz, C3), 135.6 (Ci2), 132.9 (C2), 132.2 (d, 4JCF = 3.4 Hz, Ci3), 129.3 (d, 3JCF = 8.3 Hz, Co3),
129.0 (Co2), 128.6 (Cp2), 128.5, 128.2 (Cm1,m2), 123.5 (Cp1), 121.1 (Co1), 116.2 (d, 2JCF = 21.9
Hz, Cm3). 15N NMR: δ -46.6.
(2E)-N,1-Diphenyl-3-(pyridin-3-yl)prop-2-en-1-imine (3x). Following the general procedure, 3x
was prepared from 1a (1 mmol, 0.181 g) and 2j (1 mmol, 0.103 g). 3x was isolated as a mixture
of 1E,2E/1Z,2E-isomers in a 2:1 molar ratio (0.088 g, 31% yield). Light yellow solid; m.p.: 116-
119 oC. Anal. Calcd for C20H16N2: C, 84.48; H, 5.67; N, 9.85. Found: C, 84.61; H, 5.57; N, 9.78.
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IR (film): νmax 3055, 3029, 2967, 2924, 2856, 1617, 1583, 1568, 1516, 1482, 1446, 1415, 1313,
1280, 1209, 1175, 1124, 1098, 1074, 1023, 977, 910, 827, 770, 735, 700. 1E,2E-3x. 1H NMR: δ
8.49-8.42 (m, 2H, H2',6'), 7.72-7.65 (m, 2H, Ho2), 7.59-7.52 (m, 1H, H4'), 7.49-7.39 (m, 3H,
Hm2,p2), 7.36-7.27 (m, 2H, Hm1), 7.29-7.02 (m, 1H, H5'), 7.22-7.02 (m, 1H, Hp1), 6.95-6.80 (m,
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4H, H2,3,o1). C {1H} NMR: δ 166.4 (C1), 150.8 (Ci1), 150.2 (C6'), 149.4 (C2'), 139.0 (Ci2),
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137.7 (C3), 133.5 (C4'), 133.5 (C3'), 130.1 (Cp2), 129.3, 129.0, 128.5 (Co2,m1,m2), 124.2, 123.9,
123.6 (C2,5',p1), 120.6 (Co1). 1Z,2E-3x. 1H NMR: δ 8.62-8.42 (m, 2H, H2',6'), 7.82-7.74 (m, 1H,
H4'), 7.28-7.02 (m, 9H, H2,5',Ar), 6.90-6.85 (m, 1H, Hp1), 6.77 (d, 3J = 16.4 Hz, 1H, H3), 6.63-
6.58 (m, 2H, Ho1). 13C {1H} NMR: δ 168.3 (C1), 150.5 (Ci1), 150.1 (C6'), 149.3 (C2'), 137.3 (C3),
135.1 (Ci2), 133.7 (C4'), 131.6 (C3'), 131.4 (C2), 128.9 (Co2), 128.7 (Cp2), 128.4, 128.2 (Cm1,m2),
123.7, 123.6 (C5',p1), 121.0 (Co1).
(2E)-N,1-Diphenyl-3-(thiophen-3-yl)prop-2-en-1-imine (3y). Following the general procedure, 3y
was prepared from 1a (1 mmol, 0.181 g) and 2k (1 mmol, 0.108 g). 3y was isolated as a mixture
of 1E,2E/1Z,2E-isomers in a 2:1 molar ratio (0.150 g, 52% yield). Light yellow oil. Anal. Calcd
for C19H15NS: C, 78.86; H, 5.22; N, 4.84; S, 11.08. Found: C, 78.99; H, 5.34; N, 4.75; S, 10.91.
IR (film): νmax 3092, 3059, 3028, 2958, 2924, 2859, 1615, 1584, 1515, 1483, 1445, 1312, 1256,
1206, 1163, 1077, 1023, 972, 908, 866, 833, 772, 697. 1E,2E-3y. 1H NMR: δ 7.73-7.64 (m, 2H,
Ho2), 7.51-7.42 (m, 3H, Hm2,p2), 7.38-7.29 (m), 7.29-7.20 (m), 7.14-7.04 (m) [6H, H2',4',5',Ar],
6.96-6.93 (m, 2H, Ho1), 6.90 (d, 3J = 16.3 Hz, 1H, H3), 6.71 (d, 3J = 16.3 Hz, 1H, H2). 13C {1H}
NMR: δ 167.4 (C1), 151.1 (Ci1), 139.5 (Ci2), 138.9 (C3), 135.6 (C3'), 129.9 (Cp2), 129.4, 129.0,
128.5 (Co2,m1,m2), 126.8, 126.2, 125.2 (C2',4',5'), 124.0 (Cp1), 121.9 (C2), 120.8 (Co1). 15N NMR:
δ -51.8. 1Z,2E-3y. 1H NMR: δ 7.38-7.29 (m), 7.29-7.20 (m), 7.14-7.04 (m) [11H, H2,2',4',5',Ar],
6.90-6.84 (m, 1H, Hp1), 6.80 (d, 3J = 16.2 Hz, 1H, H3), 6.66-6.59 (m, 2H, Ho1). 13C {1H} NMR:
δ 169.2 (C1), 150.9 (Ci1), 139.0 (C3), 135.6 (Ci2), 135.2 (C3'), 131.8 (C2), 129.1 (Co2), 128.5
(Cp2), 128.4, 128.2 (Cm1,m2), 126.8, 126.0, 125.3 (C2',4',5'), 123.34 (Cp1), 121.2 (Co1). 15N NMR:
δ -48.1.
ASSOCIATED CONTENT
AUTHOR INFORMATION
Corresponding Author
*E-mail: boris_trofimov@irioch.irk.ru
ORCID
Boris A. Trofimov: 0000-0002-0430-3215
Elena Yu. Schmidt: 0000-0002-0188-3015
Notes
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The authors declare no competing financial interest.
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Supporting Information
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The Supporting Information is available free of charge on the ACS Publications website at DOI:
10.1021/acs.joc. Copies of 1H and 13C NMR spectra of all compounds, and crystallographic data
(PDF).
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ACKNOWLEDGMENT
This work was financially supported by a grant from the Russian Scientific Foundation (Project
No. 19-13-00052). Authors thank the Baikal Analytical Centre of collective use for the equipment.
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