Oxidative alkynylation of imines with alkynylcopper reagents: A straightforward and practical entry to ynimines

Article abstract of DOI:10.1055/s-0031-1289760

We have developed an efficient and general synthesis of ynimines based on an oxidative cross-coupling between imines and alkynylcopper reagents. Upon simple addition of 1,2-dimethylimidazole in the presence of oxygen, these bench-stable, crystalline, and readily available polymeric compounds were found to be especially suitable reagents for the introduction of an alkynyl group into a wide range of ketimines at room temperature and under especially mild conditions.

Full text of DOI:10.1055/s-0031-1289760

SPECIAL TOPIC
▌1491
special topic
Oxidative Alkynylation of Imines with Alkynylcopper Reagents: A Straight-
forward and Practical Entry to Ynimines
Efficient and General Synthesis of Ynimines
Anouar Laouiti,a,b Kévin Jouvin,a Flavien Bourdreux,a Mohamed M. Rammah,b Mohamed B. Rammah,b
Gwilherm Evano*a,c
a
Institut Lavoisier de Versailles, UMR CNRS 8180, Université de Versailles Saint-Quentin en Yvelines, 45, Avenue des Etats-Unis, 78035
Versailles Cedex, France
b
Laboratoire de Chimie Organique Hétérocyclique, Département de Chimie, Faculté des Sciences de Monastir, Université de Monastir, Avenue
de l’environnement, 5019 Monastir, Tunisia
c
Laboratoire de Chimie Organique, Service de Chimie et PhysicoChimie Organiques, Université Libre de Bruxelles, Avenue F. D. Roosevelt
50, CP160/06, 1050 Brussels, Belgium
Fax +32(2)6502798; E-mail: gevano@ulb.ac.be
Received: 29.02.2012; Accepted after revision: 07.03.2012
and Knochel,9 who demonstrated the full potential of the
Abstract: We have developed an efficient and general synthesis of
oxidative coupling of amidocuprates, we recently report-
ynimines based on an oxidative cross-coupling between imines and
ed the aerobic cross-coupling of alkynylcopper reagents 1
and N- or P-nucleophiles 2 and 3, a strategy that was es-
alkynylcopper reagents. Upon simple addition of 1,2-dimethylimid-
azole in the presence of oxygen, these bench-stable, crystalline, and
readily available polymeric compounds were found to be especially pecially efficient and practical for the preparation of yn-
amides 4 and alkynylphosphonates 5 (Scheme 2).10 In
suitable reagents for the introduction of an alkynyl group into a
wide range of ketimines at room temperature and under especially
mild conditions.
continuation of this work and in connection with our inter-
est in the chemistry of ynamides and related molecules,11
Key words: copper, cross coupling, alkynes, imines, organometal-
lic reagents, oxidation
we now report the extension of this procedure to the syn-
thesis of ynimines by oxidative alkynylation of imines
with copper acetylides.
One of the first mentions of a copper acetylide dates from
1870 in a remarkable publication by Carl Glaser where he
reported, among other reactions, the ‘copper complexes of
phenylacetylene’.1 A peculiar property of these highly
crystalline, polymeric reagents 1,2 readily prepared by
Scheme 1 Typical syntheses of copper acetylides
simply stirring a solution of the corresponding alkyne and
copper(I) iodide in a mixture of aqueous ammonia and
ethanol or in N,N-dimethylformamide in the presence of
potassium carbonate (Scheme 1),2 is their stability, in-
comparable to the corresponding alkyl, vinyl, or aryl de-
rivatives. This was nicely highlighted in Jean-François
Normant’s review on organocopper compounds where he
commented that these reagents ‘are hydrolyzed only by
hydrochloric acid at elevated temperature or by an aque-
ous solution of alkali metal cyanide’.3 While their use had,
for a long time, been limited to the analytical detection of
alk-1-ynes, they have also found numerous applications in
C–C bond forming reactions, the most famous examples
certainly being the Cadiot–Chodkiewicz4 or the Castro–
Stephens2d reactions.
EWG
R2
2
or
EWG
R2
H
H
N
R1
N
4
or
ligand
O2, r.t.
R1
+
Cu
1
O
O
P
OR2
OR2
R1
OR2
OR2
P
3
5
Scheme 2 Alkynylation of N- and P-nucleophiles by oxidative
cross-coupling with alkynylcopper reagents
Ynimines 8 are an attractive stable variant of ynamines
that benefit, compared to the more classical ynamides,12
from the presence of an easily removable protecting
group. While the chemistry of ynamides has dramatically
expanded over the past decade, mostly because of the de-
velopment of efficient methods for their synthesis,
ynimines have received considerably less attention.13 The
development of their chemistry has, in fact, been ham-
pered by the lack of general and practical methods for
their preparation. Besides their classical and low-yielding
synthesis based on the reaction between oxime tosylates 7
In sharp contrast, little attention has been paid to the oxi-
dation chemistry of copper acetylides, despite the huge
potential of the formal umpolung of the starting alkynyl-
copper reagents under oxidative conditions.5 Inspired by
the pioneering work of Yamamoto,6 Snieckus,7 Ricci,8
SYNTHESIS 2012, 44, 1491–1500
Advanced online publication: 12.04.2012
0
0
3
9
-
7
8
8
1
1
4
3
7
-
2
1
0
X
DOI: 10.1055/s-0031-1289760; Art ID: SS-2012-C0204-ST
© Georg Thieme Verlag Stuttgart · New York

1492
A. Laouiti et al.
SPECIAL TOPIC
with higher-order alkynylcuprates 6,13,14 we reported in imines, most reactions being faster and cleaner in polar
early 2012 an alternative route based on the copper-cata- solvents such as acetonitrile or N,N-dimethylformamide.
lyzed oxidative alkynylation of imines 10 with terminal The combination of 1,2-dimethylimidazole and acetoni-
alkynes 9 (Scheme 3).11f While this procedure provided a trile gave the best results, ynimine 13a being formed in
more practical and general entry to ynimines 8, it does, 57% yield with this system, a yield that is comparable
however, still suffer from two major limitations: (1) the with the one obtained with our less practical first genera-
use of diarylimines only, mostly due to the base sensitivity tion synthesis.
of other ketimines which were not compatible with the re-
action conditions; and (2) the need for a slow addition of
the alkyne in order to minimize its dimerization, which di-
minishes its practicality on a large scale. Basing on our
studies on the oxidative alkynylation of amides and oxa-
zolidinones with copper acetylides 1,10 we thought that
the extension of this procedure to the use of imines 10
might provide a more practical second-generation synthe-
sis of ynimines.
Figure 1 Optimization of the oxidative alkynylation of imines with
copper acetylides (NMR yields using Ph2CH2 as internal standard)
The optimized conditions for the oxidative cross-coupling
of imines and copper acetylides in hand, we next moved
to the study of the scope and limitations of this reaction.
With this goal in mind, the coupling of two copper
acetylides, pentynyl- (1a) and octynylcopper (1b), with
various representative imines 10 was first studied. A vari-
ety of ynimines were prepared in moderate to good yields,
which nicely compare with those obtained via other pro-
cedures, by simply stirring a combination of the starting
imine, the alkynylcopper reagent and 1,2-dimethylimid-
azole in acetonitrile under oxygen at room temperature
and without the need for an additional base (Scheme 4).
Scheme 3 Evolution of ynimine synthesis: towards a second-gener-
ation procedure
To test this hypothesis, we decided to investigate the cross
coupling between copper(I) hexylacetylide (11) and com-
mercially available benzophenone imine (12), the latter
being used in excess to minimize the homocoupling of the
former. As in our original procedure, oxygen was chosen
as the oxidant for practical reasons (abundance, low cost,
lack of toxic byproducts), and all combinations of repre-
sentative ligands [pyridine, N,N,N′,N′-tetramethylethyl-
enediamine (TMEDA), N-methylimidazole (NMI), and
1,2-dimethylimidazole (DMI)] and solvents susceptible to
promote the alkynylation were evaluated. Results from
these studies are shown in Figure 1. While pyridine was
found to have little efficiency, N,N,N′,N′-tetramethyl-
ethylenediamine was more efficient but mostly accelerated
the dimerization of 1. The use of imidazoles as ligands re-
sulted in an enhanced reactivity, the more electron-rich
1,2-dimethylimidazole being slightly superior in terms of
reaction rate and yields. To our surprise, and in sharp con-
trast with the oxidative alkynylation of amides and dialkyl
phosphites, a strong solvent effect was observed with
The reaction was found to be compatible with a variety of
substituents on the starting imine and the presence of elec-
tron-donating or -withdrawing groups had little effect on
the outcome of the reaction. Diarylketimines, which were
the best and only substrates for our first-generation cop-
per-catalyzed synthesis, were less efficient in this case
than arylketimines which were smoothly transformed to
the corresponding ynimines 16–25. Various alkyl substit-
uents were tolerated on the starting imine and even aceto-
phenone-derived ketimines, which are highly sensitive to
both basic and acidic conditions, could be transformed to
ketimines 23a and 23b in acceptable yields. The presence
of a bulky tert-butyl group however had a detrimental ef-
fect and considerably slowed down, or even completely
blocked, the reaction, which is most certainly due to the
poor ability of the starting imines to coordinate to the cop-
Synthesis 2012, 44, 1491–1500
© Georg Thieme Verlag Stuttgart · New York

SPECIAL TOPIC
Efficient and General Synthesis of Ynimines
1493
per center. Compared to our first generation procedure bon atom substituted with the alkyl group, which was
where the volatility of some alkynes was a strong limita- significantly deshielded in the Z isomers due to the cis re-
tion and considerably reduced the yields, the use of copper lationship between the alkyne and the aromatic group
acetylides was more practical and, therefore, brings a use- (typically δ = 94–97 ppm for the Z-isomers and δ = 88–91
ful solution to this problem.
ppm for the E-isomers). A similar effect was observed for
the propargylic methylene protons, which were also sig-
nificantly deshielded in the Z isomers (Figure 2). Reasons
for the observed changes in selectivity are still unclear and
we could not find a reasonable explanation that would ac-
count for the dramatic effect of these subtle changes on
the substitution pattern of the starting imine.
R1
N
H
N
DMI, O2
R3
R1
Cu
R3
+
R2
MeCN, r.t., 12 h
R2
13, 15–27
10
1
a: R1 = Pr
b: R1 = Hex
R1
N
δC: 94–97 ppm
δC: 89–91 ppm
R1
N
R1
N
Bu
R1
R1
R3
N
N
H
H
R2
H
H
R2
13a: 28%
13b: 57%
15a: 31%, Z/E = 50:50
15b: 44%, Z/E = 50:50
16a: 44%, Z/E > 95:5
16b: 48%, Z/E > 95:5
R3
R1
N
R1
N
δH: 2.5–2.6 ppm
δH: 2.0–2.2 ppm
R1
N
Bu
Bu
Bu
Figure 2 Representative and typical chemical shifts for E- and Z-
ynimine isomers
The reaction scope was also investigated with respect to
the copper acetylide 1 using 1-(2,3-dimethylphenyl)pen-
tan-1-imine (28) as a test substrate (Scheme 5). The oxi-
dative alkynylation proceeded smoothly in all cases,
affording mixtures of E- and Z-isomers of the desired
ynimines in moderate to good yields.
17a: 85%, Z/E = 50:50 18a: 91%, Z/E = 40:60
19a: 62%, Z/E = 57:43
19b: 73%, Z/E = 55:45
17b: 72%, Z/E = 50:50
(75% on a 1.5 g scale)
18b: 74%, Z/E = 40:60
R1
N
R1
N
R1
N
Bu
Bu
Bu
Cl
OMe
The reaction is compatible with a variety of alkyl- and
aryl-substituted alkynylcopper reagents and even the
presence of an additional ferrocene on the starting copper
acetylide did not interfere with the oxidative cross-
coupling.
20a: 47%, Z/E > 95:5
20b: 55%, Z/E > 95:5
21a: 38%, Z/E = 74:26
21b: 57%, Z/E = 77:23
22a: 69%, Z/E = 50:50
22b: 66%, Z/E = 53:47
R1
N
R1
N
R1
N
From a practical point of view, it should be mentioned that
the endpoint of the reaction is remarkably easy to detect
since the reaction mixture turns from a heterogeneous yel-
low suspension to a deep green homogeneous solution
upon completion, which can then be concentrated and di-
rectly loaded onto silica gel.
Cl
OMe
23a: 60%, Z/E = 78:22
23b: 50%, Z/E = 74:26
24a: 43%, Z/E = 46:54
24b: 58%, Z/E = 45:55
25a: 44%, Z/E = 64:36
25b: 52%, Z/E = 62:38
R1
N
R1
N
In conclusion, we have developed a general, efficient, and
practical synthesis of ynimines by oxidative alkynylation
of imines with copper acetylides. These perfectly stable,
highly crystalline reagents were shown to be especially ef-
ficient reagents for the introduction of an alkyne group
under remarkably mild conditions, without the need for a
base, thermal activation, or slow addition of one of the re-
agent. The oxidative alkynylation of imines can conve-
niently be performed without precautions or inert
atmosphere and do not require the use of expensive chem-
icals. This should expand the oxidative chemistry of org-
anocopper compounds and should contribute to the
development of the chemistry of ynimines, building
blocks with enormous potential that have clearly been un-
derstudied. Extension of our oxidative alkynylation to
other substrates and detailed mechanistic studies are under
way and will be reported in due course.
26a: 9%, Z/E < 5:95
26b: 11%, Z/E < 5:95
27a: –
27b: –
Scheme 4 Oxidative cross-coupling of pentynyl- and octynylcopper
with representative imines
Interestingly, the reaction is easily performed on a gram
scale, as demonstrated with the synthesis of ynimine 18a
on a 1.5-gram scale in 75% yield.
As shown by analysis of the E/Z ratio of ynimines from
Scheme 4, the stereochemical outcome of the alkynylation
was found to be strongly dependent on the substitution
pattern of the starting imines and subtle and remote
changes had a strong effect on the proportion of the E- and
Z-isomers; the latter was the major stereoisomer in most
cases. The stereochemistry of all ynimines could be as-
signed by comparison of the chemical shifts of the sp car-
© Georg Thieme Verlag Stuttgart · New York
Synthesis 2012, 44, 1491–1500

1494
A. Laouiti et al.
SPECIAL TOPIC
with DMI (384 mg, 4.0 mmol) and the mixture was vigorously
stirred at r.t. and under an atmosphere of O2 (balloon). After com-
plete disappearance of the alkynylcopper reagent (complete disso-
lution to a deep green homogeneous mixture: typically 12 h), the
crude mixture was concentrated under vacuum and the residue was
finally purified by flash chromatography (Et3N-deactivated silica
gel) to afford the desired ynimine.
H
N
R
N
Bu
Bu
DMI, O2
R
Cu
+
MeCN, r.t., 12 h
1
18, 29–35
28
Pr
N
Hex
N
N-(Diphenylmethylene)pent-1-yn-1-amine (13a)
Orange oil; yield: 70 mg (28%).
Bu
Bu
IR (ATR): 3680, 2968, 2932, 2248, 1953, 1651, 1446, 1269, 1073,
761, 691, 638 cm–1.
1H NMR (300 MHz, CDCl3): δ = 7.63 (d, J = 7.1 Hz, 2 H), 7.40–
7.36 (m, 6 H), 7.31–7.18 (m, 2 H), 2.32 (t, J = 6.9 Hz, 2 H), 1.37
(app. sext, J = 7.2 Hz, 2 H), 0.77 (t, J = 7.2 Hz, 3 H).
18a: 91%, Z/E = 40:60
Ph
18b: 74%, Z/E = 40:60
N
N
Bu
Bu
13C NMR (75 MHz, CDCl3): δ = 177.2, 138.1, 136.5, 131.2, 129.7,
129.2, 128.5, 128.2, 128.0, 96.3, 83.7, 22.5, 22.3, 13.4.
MS (ESI+): m/z = 249.1, 248.1.
HRMS (ESI): m/z [M + H]+ calcd for C18H18N: 248.1439; found:
29: 47%, Z/E = 41:59
30: 57%, Z/E = 42:58
248.1434.
MeO
N
F
N
Bu
Bu
N-(Diphenylmethylene)oct-1-yn-1-amine (13b)
Orange oil; yield: 165 mg (57%).
IR (ATR): 2919, 2848, 2246, 1661, 1444, 1313, 1274, 761, 692, 638
cm–1.
31: 58%, Z/E = 42:58
32: 52%, Z/E = 40:60
1H NMR (300 MHz, CDCl3): δ = 7.73 (d, J = 7.5 Hz, 2 H), 7.48–
7.44 (m, 6 H), 7.40–7.35 (m, 2 H), 2.43 (t, J = 6.8 Hz, 2 H), 1.45–
140 (m, 2 H), 1.31–1.23 (m, 6 H), 0.88 (t, J = 9.6 Hz, 3 H).
13C NMR (75 MHz, CDCl3): δ = 177.2, 138.2, 136.5, 131.2, 129.6,
129.2, 128.6, 128.3, 128.0, 96.5, 83.7, 31.5, 29.1, 28.4, 22.6, 20.3,
14.2.
OMe
N
N
Bu
Bu
33: 49%, Z/E = 62:38
34: 48%, Z/E = 55:45
MS (ESI+): m/z = 486.2, 485.2, 413.3, 369.3, 301.1, 290.1, 282.2,
184.9, 414.9, 139.9.
N
HRMS (ESI): m/z [M + H]+ calcd for C21H24N: 290.1909; found:
Bu
Fe
290.1902.
N-[Phenyl(3-tolyl)methylene]pent-1-yn-1-amine (15a)
Orange oil; yield: 80 mg (31%); ratio Z/E 50:50.
35: 62%, Z/E = 38:62
IR (ATR): 2959, 2919, 2844, 1546, 1440, 1326, 785, 693 cm–1.
Scheme 5 Oxidative cross-coupling of 1-(2,3-dimethylphenyl)pen-
tan-1-imine with representative alkynylcopper reagents
1H NMR (300 MHz, CDCl3): δ = 7.74 (d, J = 7.3 Hz, 1 H), 7.62 and
7.46 (2 × s, 1 H)*, 7.50 (s, 3 H), 7.41–7.24 (m, 4 H), 2.44 and 2.42
(t, J = 6.9 Hz, t, J = 6.8 Hz, 2 H)*, 2.42 and 2.38 (2 × s, 3 H)*, 1.54–
1.41 (m, 2 H), 0.88 and 0.87 (t, J = 7.3 Hz, t, J = 7.3 Hz, 3 H)*.
* Stereoisomers.
13C NMR (75 MHz, CDCl3): δ = 177.4, (138.3 and 138.1)*, (137.9
and 137.7)*, (136.6 and 136.4)*, (132.0 and 131.1)*, (130.4 and
129.6)*, (129.5 and 129.0)*, (129.2 and 128.5)*, (128.2 and
128.0)*, (128.1 and 127.9)*, (126.8 and 125.7)*, (96.1 and 96.0)*,
(83.8 and 83.7)*, 22.5, (22.3 and 22.2)*, (21.4 and 21.3)*, (13.4 and
13.3)*. * Stereoisomers.
All solvents were reagent grade. DMF, MeCN, CH2Cl2, pyridine,
and TMEDA were freshly distilled from CaH2. THF, dioxane, and
toluene were freshly distilled from Na/benzophenone under argon.
Copper acetylides were prepared from the corresponding alkynes
using our previously reported procedures.10 All other reagents were
used as supplied. Reactions were magnetically stirred. Flash chro-
matography was performed with silica gel 60 (particle size 35–70
μm) supplied by SDS. Yields refer to chromatographically and
spectroscopically pure compounds. 1H NMR spectra were recorded
using an internal deuterium lock at r.t. on Bruker 300 or 400 MHz
spectrometers. Internal references of δH = 7.26 ppm was used for
CDCl3. Resonances that are either partially or fully obscured are de-
noted obscured (obs.). 13C NMR spectra were recorded at 75 and
100 MHz. Internal references of δC = 77.16 ppm was used for
CDCl3. Melting points were recorded on a Buchi B-545. Infrared
spectra were recorded on a Nicolet iS 10 (SMART iTR diamond
ATR) spectrophotometer. HRMS were obtained on a Waters Xevo
Qtof spectrometer.
MS (ESI+): m/z = 263.1, 262.2.
HRMS (ESI): m/z [M + H]+ calcd for C19H20N: 262.1596; found:
262.1599.
N-[Phenyl(3-tolyl)methylene]oct-1-yn-1-amine (15b)
Orange oil; yield: 133 mg (44%); ratio Z/E 50:50.
IR (ATR): 2927, 2856, 1657, 1448, 1321, 793, 682 cm–1.
1H NMR (300 MHz, CDCl3): δ = 7.63 (d, J = 7.2 Hz, 1 H), 7.52 and
7.35 (2 × s, 1 H)*, 7.38 (s, 3 H), 7.30–7.16 (m, 4 H), 2.35 and 2.33
(t, J = 6.8 Hz, t, J = 6.8 Hz, 2 H)*, 2.31 and 2.27 (2 × s, 3 H)*, 1.42–
1.28 (m, 2 H), 1.22–1.11 (m, 6 H), 0.79 (t, J = 6.4 Hz, 3 H). * Ste-
reoisomers.
Ynimines 13, 15–35; General Procedure
A 10-mL round-bottom flask was successively charged with the
imine (8.0 mmol), the alkynylcopper reagent (2.0 mmol), and
MeCN (8 mL). The resulting bright yellow slurry was then treated
Synthesis 2012, 44, 1491–1500
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SPECIAL TOPIC
Efficient and General Synthesis of Ynimines
1495
13C NMR (75 MHz, CDCl3): δ = (175.8 and 175.7)*, (136.6 and
136.5)*, (136.3 and 136.0)*, (135.0 and 134.8)*, (130.4 and
129.5)*, (128.7 and 127.9)*, (127.8 and 127.4)*, (127.6 and
126.9)*, (126.6 and 126.3)*, (126.5 and 126.2)*, (125.1 and
124.0)*, (94.6 and 94.5)*, (82.1 and 82.0)*, 29.8, (27.5 and 27.4)*,
26.8, 20.9, (19.8 and 19.7)*, (18.7 and 18.6)*, 12.5. * Stereoiso-
mers.
1H NMR (300 MHz, CDCl3): δ = 7.32 and 7.04 (obs. d, J = 7.6 Hz,
d, J = 7.6 Hz, 1 H)*, 7.29–7.21 (m, 3 H), 2.97 and 2.66 (t, J = 7.5
Hz, t, J = 7.4 Hz, 2 H)*, 2.59 and 2.25 (t, J = 6.9 Hz, obs. t, J = 6.7
Hz, 2 H)*, 2.43 and 2.28 (2 × s, 3 H), 1.64–1.47 (m, 4 H), 1.41–1.31
(m, 5 H), 1.28–1.11 (m, 3 H), 0.95–0.83 (m, 6 H). * Stereoisomers.
13C NMR (75 MHz, CDCl3): δ = (185.7 and 185.4)*, (139.9 and
138.9)*, (136.3 and 134.1)*, (131.2 and 130.1)*, 129.0, (128.4 and
127.9)*, (125.5 and 125.4)*, (95.2 and 89.1)*, (82.3 and 81.6)*,
(40.7 and 37.2)*, (31.5 and 31.4)*, 29.3, 29.0, 28.7, 28.4, (28.1 and
28.0)*, 22.8, (22.6 and 22.5)*, 20.8, 20.1, (19.5 and 19.3)*, 14.1,
(13.9 and 13.8)*. * Stereoisomers.
MS (ESI+): m/z = 306.2, 305.2, 304.2.
HRMS (ESI): m/z [M + H]+ calcd for C22H26N: 304.2065; found:
304.2066.
(Z)-N-(1-Phenylpentylidene)pent-1-yn-1-amine (16a)
MS (ESI+): m/z = 298.2, 285.2, 284.2, 124.0.
HRMS (ESI): m/z [M + H]+ calcd for C20H30N: 284.2378; found:
384.2380.
Yellow oil; yield: 100 mg (44%).
IR (ATR): 2958, 2929, 2870, 2360, 2341, 2192, 1559, 1446, 1327,
1188, 1011, 808, 760, 689 cm–1.
1H NMR (300 MHz, CDCl3): δ = 7.90 (d, J = 7.8 Hz, 2 H), 7.48–
7.37 (m, 3 H), 3.03 (t, J = 7.7 Hz, 2 H), 2.58 (t, J = 6.9 Hz, 2 H),
1.70–1.60 (m, 4 H), 1.44 (app. sext, J = 7.2 Hz, 2 H), 1.06 (t, J = 7.3
Hz, 3 H), 0.96 (t, J = 7.3 Hz, 3 H).
N-[1-(2,3-Dimethylphenyl)pentylidene]pentyn-1-yn-1-amine
(18a)
Yellow oil; yield: 232 mg (91%); 1.5-g scale reaction; yield: 75%;
ratio Z/E 40:60.
IR (ATR): 2958, 2929, 2871, 2361, 2341, 1597, 1456, 1378, 1337,
1274, 1177, 1087, 1017, 989, 784, 749, 722 cm–1.
13C NMR (75 MHz, CDCl3): δ = 181.6, 137.2, 131.1, 128.6, 127.2,
96.3, 82.9, 33.4, 29.5, 23.0, 22.9, 22.4, 13.9, 13.7.
1H NMR (300 MHz, CDCl3): δ (major isomer) = 7.17–7.06 (m, 2
H), 6.90–6.86 (m, 1 H), 2.65 (t, J = 7.5 Hz, 2 H), 2.29 (s, 3 H), 2.22
(t, J = 6.8 Hz, 2 H), 2.13 (s, 3 H), 1.66–1.58 (m, 2 H), 1.56–1.26 (m,
4 H), 0.91 (t, J = 7.3 Hz, 3 H), 0.69 (t, J = 7.3 Hz, 3 H); δ (minor
isomer) = 7.17–7.06 (m, 3 H), 2.92 (t, J = 7.6 Hz, 2 H), 2.55 (t, J =
6.9 Hz, 2 H), 2.13 (s, 3 H), 2.25 (s, 3 H), 1.66–1.58 (m, 2 H), 1.56–
1.26 (m, 4 H), 1.05 (t, J = 7.3 Hz, 3 H), 0.89 (t, J = 7.0 Hz, 3 H).
MS (ESI+): m/z = 229.2, 228.2.
HRMS (ESI): m/z [M + H]+ calcd for C16H22N: 228.1752; found:
228.1749.
(Z)-N-(1-Phenylpentylidene)oct-1-yn-1-amine (16b)
Yellow oil; yield: 130 mg (48%).
IR (ATR): 2949, 2925, 2851, 1585, 1560, 1442, 1327, 1184, 1012,
755, 686 cm–1.
1H NMR (300 MHz, CDCl3): δ = 7.90 (d, J = 6.7 Hz, 2 H), 7.46–
7.40 (m, 3 H), 3.03 (t, J = 7.7 Hz, 2 H), 2.60 (t, J = 6.9 Hz, 2 H),
1.63–1.57 (m, 4 H), 1.49–1.43 (m, 4 H), 1.35–1.31 (m, 4 H), 0.98–
0.89 (m, 6 H).
13C NMR (75 MHz, CDCl3): δ (major isomer) = 186.2, 140.2,
137.3, 132.7, 130.0, 125.5, 123.2, 88.8, 82.7, 41.1, 28.1, 22.7, 22.6,
21.7, 20.4, 16.6, 14.0, 13.1; δ (minor isomer) = 187.1, 140.0, 137.8,
134.2, 130.5, 125.4, 125.3, 94.1, 81.8, 38.1, 28.3, 23.0, 22.9, 22.2,
20.6, 16.9, 13.9, 13.7.
MS (ESI+): m/z = 257.2, 256.2, 173.1.
HRMS (ESI): m/z [M + H]+ calcd for C18H26N: 256.2065; found:
256.2065.
13C NMR (75 MHz, CDCl3): δ = 181.5, 137.1, 131.0, 128.5, 127.1,
96.5, 82.7, 33.4, 31.5, 29.4, 29.3, 28.7, 23.0, 22.6, 20.3, 14.1, 13.8.
MS (ESI+): m/z = 272.2, 271.2, 270.2, 124.0.
HRMS (ESI): m/z [M + H]+ calcd for C19H28N: 270.2222; found:
270.2221.
N-[1-(2,3-Dimethylphenyl)pentylidene]octyn-1-yn-1-amine
(18b)
Yellow oil; yield: 220 mg (74%); ratio Z/E 40:60.
IR (ATR): 2955, 2927, 2856, 2360, 2341, 2202, 1597, 1456, 1378,
1328, 1177, 1081, 1018, 989, 778, 750, 721, 668 cm–1.
N-[1-(o-Tolyl)pentylidene]pent-1-yn-1-amine (17a)
Yellow oil; yield: 205 mg (85%); ratio Z/E 50:50.
1H NMR (300 MHz, CDCl3): δ (major isomer) = 7.19–7.10 (m, 2
H), 6.91–6.88 (m, 1 H), 2.66 (t, J = 7.4 Hz, 2 H), 2.31 (s, 3 H), 2.26
(obs. t, J = 6.9 Hz, 2 H), 2.15 (s, 3 H), 1.66–1.57 (m, 2 H), 1.53–1.09
(m, 10 H), 0.97 (t, J = 7.2 Hz, 3 H), 0.91 (t, J = 6.9 Hz, 3 H); δ (mi-
nor isomer) = 7.19–7.10 (m, 3 H), 2.94 (t, J = 7.6 Hz, 2 H), 2.58 (t,
J = 6.9 Hz, 2 H), 2.31 (s, 3 H), 2.27 (s, 3 H), 1.66–1.57 (m, 2 H),
1.53–1.09 (m, 10 H), 0.97 (t, J = 7.2 Hz, 3 H), 0.86 (t, J = 7.2 Hz, 3
H).
13C NMR (75 MHz, CDCl3): δ (major isomer) = 186.2, 140.2,
137.2, 132.7, 130.0, 125.5, 123.2, 89.0, 82.6, 41.1, 31.5, 29.1, 28.2,
28.1, 22.7, 22.6, 20.4, 19.6, 16.6, 14.3, 14.0; δ (minor isomer) =
187.1, 140.0, 137.8, 134.2, 130.5, 125.4, 125.3, 94.3, 81.7, 38.1,
31.6, 29.5, 28.8, 28.3, 23.0, 22.8, 20.6, 20.2, 16.9, 14.3, 13.9.
IR (ATR): 2958, 2929, 2863, 2204, 1685, 1587, 1457, 1375, 1334,
1128, 1036, 751, 726 cm–1.
1H NMR (300 MHz, CDCl3): δ = 7.33 and 7.04 (obs. d, J = 7.6 Hz,
d, J = 7.1 Hz, 1 H)*, 7.30–7.19 (m, 3 H), 2.97 and 2.66 (t, J = 7.6
Hz, t, J = 7.4 Hz, 2 H)*, 2.57 and 2.23 (t, J = 6.9 Hz, t, J = 6.8 Hz,
2 H)*, 2.43 and 2.28 (2 × s, 3 H), 1.66–1.52 (m, 3 H), 1.44–1.30 (m,
3 H), 1.06 and 0.72 (t, J = 7.3 Hz, t, J = 7.3 Hz, 3 H)*, 0.96–0.88
(m, 3 H). * Stereoisomers.
13C NMR (75 MHz, CDCl3): δ = (185.8 and 185.5)*, (139.8 and
138.9)*, (136.3 and 134.1)*, (131.2 and 130.1)*, (129.9 and
128.5)*, 127.9, (125.5 and 125.4)*, (95.0 and 88.9)*, (82.5 and
81.8)*, (40.7 and 37.2)*, (28.4 and 27.9)*, 22.8, 22.7, (22.5 and
22.4)*, 22.1, 21.5, (20.8 and 19.3)*, 13.9, 13.8, (13.6 and 13.1)*. *
Stereoisomers.
MS (ESI+): m/z = 299.3, 298.3, 124.1.
HRMS (ESI): m/z [M + H]+ calcd for C21H32N: 298.2535; found:
298.2532.
MS (ESI+): m/z = 301.1, 244.4, 243.1, 242.1, 159.1, 111.0.
HRMS (ESI): m/z [M + H]+ calcd for C17H24N: 342.1909; found:
342.1907.
N-[1-(Naphthalen-1-yl)pentylidene]pent-1-yn-1-amine (19a)
Yellow oil; yield: 171 mg (62%); ratio Z/E 57:43.
N-[1-(o-Tolyl)pentylidene]oct-1-yn-1-amine (17b)
Yellow oil; yield: 204 mg (72%); ratio Z/E 50:50.
IR (ATR): 2958, 2932, 2869, 2188, 1568, 1505, 1460, 1340, 1251,
1182, 906, 798, 776, 729 cm–1.
IR (ATR): 2951, 2923, 2853, 2195, 1587, 1451, 1381, 1324, 1178,
1036, 757, 726 cm–1.
© Georg Thieme Verlag Stuttgart · New York
Synthesis 2012, 44, 1491–1500

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A. Laouiti et al.
SPECIAL TOPIC
1H NMR (300 MHz, CDCl3): δ (major isomer) = 8.37 (d, J = 7.7 Hz,
1 H), 7.92–7.87 (m, 2 H), 7.60–7.47 (m, 4 H), 3.20 (t, J = 7.8 Hz, 2
H), 2.66 (t, J = 6.9 Hz, 2 H), 1.75–1.68 (m, 2 H), 1.64–1.59 (m, 2
H), 1.50–1.37 (m, 2 H), 1.13 (t, J = 7.4 Hz, 3 H), 0.91 (t, J = 7.2 Hz,
3 H); δ (minor isomer) = 7.92–7.87 (m, 2 H), 7.74–7.71 (m, 1 H),
7.60–7.47 (m, 3 H), 7.33 (d, J = 7.0 Hz, 1 H), 2.89 (t, J = 7.5 Hz, 2
H), 2.06 (t, J = 6.7 Hz, 2 H), 1.75–1.68 (m, 2 H), 1.50–1.37 (m, 2
H), 1.07–1.00 (m, 2 H), 0.95 (t, J = 7.2 Hz, 3 H), 0.45 (t, J = 7.3 Hz,
3 H).
(m, 4 H), 1.37–1.32 (m, 4 H), 0.99 (t, J = 7.3 Hz, 3 H), 0.93 (t, J =
7.0 Hz, 3 H).
13C NMR (75 MHz, CDCl3): δ = 179.3, 132.7, 132.5, 130.9, 127.0,
126.2, 126.0, 125.6, 125.4, 124.4, 121.8, 95.3, 80.9, 31.3, 29.5,
27.6, 27.4, 26.7, 20.9, 20.6, 18.3, 12.1, 11.9.
MS (ESI+): m/z = 322.2, 321.2, 320.2, 141.0, 124.0.
HRMS (ESI): m/z [M + H]+ calcd for C23H30N: 320.2378; found:
320.2375.
13C NMR (75 MHz, CDCl3): δ (major isomer) = 185.4, 137.2,
134.3, 131.0, 130.4, 129.2, 127.2, 126.3, 126.2, 126.1, 125.0, 96.1,
82.3, 38.2, 29.0, 23.1, 22.5, 14.1, 14.0; δ (minor isomer) = 184.7,
138.3, 133.7, 131.0, 128.7, 128.6, 126.7, 126.4, 125.7, 125.3, 123.7,
90.7, 83.1, 41.6, 28.7, 22.8, 22.4, 21.7, 14.2, 13.0.
N-[1-(2-Methoxyphenyl)pentylidene]pent-1-yn-1-amine (21a)
Yellow oil; yield: 98 mg (38%); ratio Z/E 74:26.
IR (ATR): 2955, 2923, 2869, 2831, 2204, 1593, 1486, 1470, 1432,
1239, 1182, 1020, 751 cm–1.
1H NMR (300 MHz, CDCl3): δ (major isomer) = 7.49 (dd, J = 7.6,
1.7 Hz, 1 H), 7.41–7.32 (m, 1 H), 7.00–6.91 (m, 2 H), 3.85 (s, 3 H),
3.08 (t, J = 7.6 Hz, 2 H), 2.55 (t, J = 6.9 Hz, 2 H), 1.66–1.33 (m, 6
H), 1.05 (t, J = 6.4 Hz, 3 H), 0.90 (t, J = 7.2 Hz, 3 H); δ (minor iso-
mer) = 7.41–7.32 (m, 1 H), 7.19 (dd, J = 7.6, 1.7 Hz, 1 H), 7.00–6.91
(m, 2 H), 3.82 (s, 3 H), 2.71 (t, J = 7.4 Hz, 2 H), 2.26 (t, J = 6.9 Hz,
2 H), 1.66–1.33 (m, 6 H), 1.05 (t, J = 6.4 Hz, 3 H), 0.78 (t, J = 7.4
Hz, 3 H).
13C NMR (75 MHz, CDCl3): δ (major isomer) = 185.0, 157.5,
131.2, 129.9, 128.0, 120.7, 111.1, 94.1, 82.2, 55.5, 36.7, 28.4, 22.8,
22.7, 22.1, 13.8, 13.6; δ (minor isomer) = 182.8, 155.6, 130.2,
128.7, 128.4, 120.2, 111.1, 88.6, 82.5, 55.4, 39.9, 28.4, 22.5, 22.4,
21.7, 13.9, 13.2.
MS (ESI+): m/z = 280.1, 279.1, 278.1, 124.0.
HRMS (ESI): m/z [M + H]+ calcd for C20H24N: 278.1909; found:
278.1907.
N-[1-(Naphthalen-1-yl)pentylidene]oct-1-yn-1-amine (19b)
Yellow oil; yield: 233 mg (73%); ratio Z/E 55:45.
IR (ATR): 2951, 2926, 2847, 2198, 1574, 1508, 1463, 1248, 1178,
798, 776, 729 cm–1.
1H NMR (300 MHz, CDCl3): δ (major isomer) = 8.35 (d, J = 7.5 Hz,
1 H), 7.91–7.87 (m, 2 H), 7.60–7.49 (m, 4 H), 3.18 (t, J = 7.6 Hz, 2
H), 2.67 (t, J = 6.9 Hz, 2 H), 1.75–1.62 (m, 2 H), 1.60–1.49 (m, 2
H), 1.46–1.31 (m, 4 H), 1.00–0.88 (m, 7 H), 0.83 (t, J = 7.0 Hz, 3
H); δ (minor isomer) = 7.91–7.87 (m, 2 H), 7.73–7.70 (m, 1 H),
7.60–7.49 (m, 3 H), 7.32 (d, J = 7.0 Hz, 1 H), 2.87 (t, J = 7.4 Hz, 2
H), 2.08 (t, J = 6.7 Hz, 2 H), 1.75–1.62 (m, 2 H), 1.60–1.49 (m, 2
H), 1.46–1.31 (m, 4 H), 1.15–1.08 (m, 4 H), 1.00–0.81 (m, 6 H).
MS (ESI+): m/z = 260.1, 259.1, 258.1.
HRMS (ESI): m/z [M + H]+ calcd for C17H24NO: 258.1858; found:
258.1860.
13C NMR (75 MHz, CDCl3): δ (major isomer) = 185.1, 136.9,
134.0, 130.8, 130.0, 128.4, 126.9, 126.0, 125.9, 125.8, 124.7, 96.0,
81.9, 37.9, 31.5, 29.4, 28.7, 22.8, 22.7, 20.2, 14.2, 13.8; δ (minor
isomer) = 184.7, 138.1, 133.4, 130.8, 128.9, 128.4, 126.4, 126.1,
125.4, 125.0, 123.4, 90.6, 82.7, 41.3, 31.3, 28.6, 28.4, 27.8, 22.5,
22.4, 19.4, 14.1, 13.9.
N-[1-(2-Methoxyphenyl)pentylidene]oct-1-yn-1-amine (21b)
Yellow oil; yield: 170 mg (57%); ratio Z/E 77:23.
IR (ATR): 2951, 2923, 2853, 2201, 1600, 1489, 1463, 1435, 1239,
1182, 1026, 906, 754, 729 cm–1.
1H NMR (300 MHz, CDCl3): δ (major isomer) = 7.50 (dd, J = 7.5,
1.7 Hz, 1 H), 7.40–7.34 (m, 1 H), 6.99–6.96 (m, 2 H), 3.86 (s, 3 H),
3.05 (t, J = 7.6 Hz, 2 H), 2.57 (t, J = 6.9 Hz, 2 H), 1.61–1.47 (m, 5
H), 1.38–1.30 (m, 5 H), 1.18–1.15 (m, 2 H), 0.94–0.86 (m, 6 H); δ
(minor isomer) = 7.40–7.34 (m, 1 H), 7.20 (dd, J = 7.4, 1.6 Hz, 1 H),
6.99–6.90 (m, 2 H), 3.83 (s, 3 H), 2.71 (t, J = 7.3 Hz, 2 H), 2.28 (t,
J = 6.8 Hz, 2 H), 1.61–1.47 (m, 5 H), 1.38–1.30 (m, 5 H), 1.18–1.15
(m, 2 H), 0.94–0.86 (m, 6 H).
MS (ESI+): m/z = 322.2, 321.2, 320.2, 301.1, 124.0.
HRMS (ESI): m/z [M + H]+ calcd for C23H30N: 320.2378; found:
320.2375.
(Z)-N-[1-(Naphthalen-2-yl)pentylidene[pent-1-yn-1-amine
(20a)
Yellow oil; yield: 130 mg (47%).
13C NMR (75 MHz, CDCl3): δ (major isomer) = 185.0, 157.5,
131.2, 129.9, 128.7, 120.7, 111.0, 94.3, 82.1, 55.4, 36.8, 31.5, 29.3,
28.6, 28.4, 22.8, 22.6, 20.1, 14.1, 13.8; δ (minor isomer) = 182.8,
155.6, 130.2, 128.4, 128.0, 120.1, 111.0, 88.8, 82.1, 55.5, 39.9,
31.4, 29.1, 28.4, 28.2, 22.6, 22.4, 19.6, 14.2, 13.9.
IR (ATR): 2955, 2926, 2869, 2182, 1558, 1451, 1327, 1185, 1131,
887, 947, 855, 821, 748 cm–1.
1H NMR (300 MHz, CDCl3): δ = 8.31 (s, 1 H), 8.11 (d, J = 7.1 Hz,
1 H), 7.92–7.84 (m, 3 H), 7.57–7.52 (m, 2 H), 3.17 (t, J = 7.7 Hz, 2
H), 2.62 (t, J = 6.9 Hz, 2 H), 1.76–1.64 (m, 4 H), 1.58–1.47 (m, 2
H), 1.08 (t, J = 7.3 Hz, 3 H), 0.99 (t, J = 7.2 Hz, 3 H).
MS (ESI+): m/z = 302.2, 301.2, 300.2, 282.2, 149.0, 124.0.
HRMS (ESI): m/z [M + H]+ calcd for C20H30NO: 300.2327; found:
300.2330.
13C NMR (75 MHz, CDCl3): δ = 181.4, 134.7, 134.5, 132.9, 129.0,
128.1, 128.0, 127.7, 127.4, 126.4, 123.8, 97.1, 83.8, 33.3, 29.6,
22.9, 22.9, 22.4, 13.9, 13.7.
N-[1-(2-Chlorophenyl)pentylidene]pent-1-yn-1-amine (22a)
Yellow oil; yield: 180 mg (69%); ratio Z/E 50:50.
MS (ESI+): m/z = 280.2, 279.1, 278.1, 195.1, 124.0.
HRMS (ESI): m/z [M + H]+ calcd for C20H24N: 278.1909; found:
278.1910.
IR (ATR): 2958, 2929, 2866, 2207, 1590, 1467, 1429, 1340, 1182,
1033, 745 cm–1.
1H NMR (300 MHz, CDCl3): δ = 7.43–7.39 and 7.17–7.13 (m, 1
H)*, 7.36–7.27 (m, 3 H), 3.06 and 2.72 (t, J = 7.5 Hz, t, J = 7.4 Hz,
2 H)*, 2.57 and 2.24 (t, J = 6.9 Hz, t, J = 6.8 Hz, 2 H)*, 1.68–1.61
(m, 2 H), 1.52–1.28 (m, 4 H), 1.06 and 0.73 (t, J = 7.3 Hz, t, J = 7.3
Hz, 3 H)*, 0.92 and 0.89 (t, J = 7.3 Hz, t, J = 7.2 Hz, 3 H)*. * Ste-
reoisomers.
13C NMR (75 MHz, CDCl3): δ = (184.3 and 181.8)*, (138.8 and
138.7)*, 131.7, 130.3, 130.0, 129.8, 129.7, (129.6 and 127.7)*,
(126.7 and 126.6)*, (96.3 and 90.1)*, (82.1 and 81.4)*, (39.8 and
(Z)-N-[1-(Naphthalen-2-yl)pentylidene]oct-1-yn-1-amine (20b)
Yellow solid; yield: 175 mg (55%); mp 65 °C.
IR (ATR): 2955, 2923, 2850, 2027, 1552, 1463, 1330, 1188, 1128,
862, 833, 748, 472 cm–1.
1H NMR (300 MHz, CDCl3): δ = 8.30 (s, 1 H), 8.11 (dd, J = 7.4, 1.7
Hz, 1 H), 7.94–7.84 (m, 3 H), 7.57–7.52 (m, 2 H), 3.16 (t, J = 7.7
Hz, 2 H), 2.64 (t, J = 6.9 Hz, 2 H), 1.73–1.64 (m, 4 H), 1.62–1.47
Synthesis 2012, 44, 1491–1500
© Georg Thieme Verlag Stuttgart · New York

SPECIAL TOPIC
Efficient and General Synthesis of Ynimines
1497
36.4)*, (28.1 and 27.9)*, 22.7, 22.6, 22.4, 22.3, (22.1 and 21.5)*
13.9, 13.7, (13.6 and 13.1)*. * Stereoisomers.
N-[1-(2-Chlorophenyl)propylidene]pent-1-yn-1-amine (24a)
Yellow oil; yield: 100 mg (43%); ratio Z/E 46:54.
IR (ATR): 2964, 2932, 2869, 2201, 1587, 1463, 1429, 1340, 1229,
1052, 1026, 935, 748 cm–1.
MS (ESI+): m/z = 265.1, 264.1, 179.0.
HRMS (ESI): m/z [M + H]+ calcd for C16H21NCl: 262.1363; found:
262.1365.
1H NMR (400 MHz, CDCl3): δ (major isomer) = 7.42–7.40 (m, 1
H), 7.37–7.28 (m, 3 H), 2.75 (q, J = 7.3 Hz, 2 H), 2.24 (t, J = 6.8 Hz,
2 H), 1.68–1.62 (m, 2 H), 1.21 (t, J = 7.3 Hz, 3 H), 1.12–1.04 (m, 3
H); δ (minor isomer) = 7.37–7.28 (m, 3 H), 7.16–7.14 (m, 1 H), 3.05
(q, J = 7.6 Hz, 2 H), 2.57 (t, J = 6.9 Hz, 2 H), 1.34–1.27 (m, 2 H),
1.12–1.04 (m, 3 H), 0.73 (t, J = 7.3 Hz, 3 H).
N-[1-(2-Chlorophenyl)pentylidene]oct-1-yn-1-amine (22b)
Yellow oil; yield: 200 mg (66%); ratio Z/E 53:47.
IR (ATR): 2951, 2923, 2853, 2201, 1587, 1467, 1467, 1425, 1327,
1033, 741 cm–1.
13C NMR (100 MHz, CDCl3): δ (major isomer) = 182.5, 138.8,
131.8, 129.8, 129.6, 127.6, 126.6, 90.0, 82.0, 33.2, 22.4, 21.5, 13.1,
10.1; δ (minor isomer) = 185.2, 138.6, 130.3, 130.0, 129.8, 126.6,
125.0, 96.5, 81.3, 30.3, 22.6, 22.1, 13.6, 10.3.
1H NMR (300 MHz, CDCl3): δ (major isomer) = 7.44–7.39 (m, 1
H), 7.35–7.28 (m, 3 H), 3.05 (t, J = 7.5 Hz, 2 H), 2.59 (t, J = 6.9 Hz,
2 H), 1.65–1.59 (m, 2 H), 1.49–1.39 (m, 2 H), 1.36–1.31 (m, 4 H),
1.25–1.12 (m, 4 H), 0.95–0.84 (m, 6 H); δ (minor isomer) = 7.35–
7.28 (m, 3 H), 7.18–7.15 (m, 1 H), 2.72 (t, J = 7.4 Hz, 2 H), 2.26 (t,
J = 6.8 Hz, 2 H), 1.65–1.59 (m, 2 H), 1.49–1.39 (m, 2 H), 1.36–1.31
(m, 4 H), 1.25–1.12 (m, 4 H), 0.95–0.84 (m, 6 H).
13C NMR (75 MHz, CDCl3): δ (major isomer) = 184.3, 138.8,
131.7, 130.2, 130.0, 129.8, 126.7, 96.5, 81.3, 36.8, 31.4, 28.1, 28.0,
27.9, 22.7, 22.5, 20.1, 14.1, 13.7; δ (minor isomer) = 181.7, 138.8,
131.7, 123.7, 129.6, 127.7, 126.6, 90.3, 81.9, 39.8, 31.4, 29.2, 28.9,
28.6, 22.6, 22.4, 19.5, 14.1, 13.9.
MS (ESI+): m/z = 237.1, 236.1, 234.1, 149.0, 111.0.
HRMS (ESI): m/z [M + H]+ calcd for C14H17NCl: 234.1050; found:
234.1051.
N-[1-(2-Chlorophenyl)propylidene]oct-1-yn-1-amine (24b)
Yellow oil; yield: 160 mg (58%); ratio Z/E 45:55.
IR (ATR): 2926, 2853, 2204, 1590, 1457, 1432, 1232, 1055, 1033,
941, 748, 675 cm–1.
1H NMR (400 MHz, CDCl3): δ (major isomer) = 7.44–7.40 (m, 1
H), 7.37–7.28 (m, 3 H), 2.74 (q, J = 7.3 Hz, 2 H), 2.26 (t, J = 6.7 Hz,
2 H), 1.64–1.47 (m, 2 H), 1.33–1.28 (m, 2 H), 1.26–1.19 (m, 4 H),
1.12–1.08 (m, 3 H), 0.86 (t, J = 7.2 Hz, 3 H); δ (minor isomer) =
7.37–7.28 (m, 3 H), 1.16–1.14 (m, 1 H), 3.04 (q, J = 7.6 Hz, 2 H),
2.59 (t, J = 6.9 Hz, 2 H), 1.64–1.47 (m, 2 H), 1.33–1.28 (m, 2 H),
1.26–1.19 (m, 4 H), 1.12–1.08 (m, 3 H), 0.92 (t, J = 6.8 Hz, 3 H).
13C NMR (100 MHz, CDCl3): δ (major isomer) = 182.4, 138.8,
131.8, 129.7, 129.6, 127.6, 126.6, 90.3, 81.9, 33.2, 31.4, 28.9, 28.1,
22.5, 19.5, 14.1, 10.1; δ (minor isomer) = 185.2, 138.6, 130.2,
129.9, 129.8, 126.7, 125.0, 96.7, 81.2, 31.4, 30.3, 29.2, 28.6, 22.6,
20.1, 14.1, 10.3.
MS (ESI+): m/z = 307.1, 306.1, 304.1, 124.0.
HRMS (ESI): m/z [M + H]+ calcd for C19H27NCl: 304.1832; found:
304.1831.
N-[1-(o-Tolyl)ethylidene]pent-1-yn-1-amine (23a)
Yellow oil; yield: 120 mg (60%); ratio Z/E 78:22.
IR (ATR): 2961, 2926, 2866, 2198, 1590, 1454, 1359, 1299, 1185,
1071, 1036, 757, 722 cm–1.
1H NMR (400 MHz, CDCl3): δ (major isomer) = 7.42 (d, J = 7.4 Hz,
1 H), 7.34–7.24 (m, 3 H), 2.59 (obs. t, J = 6.9 Hz, 2 H), 2.56 (s, 3
H), 2.48 (s, 3 H), 1.66 (app. sext, J = 7.1 Hz, 2 H), 1.08 (t, J = 7.3
Hz, 3 H); δ (minor isomer) = 7.34–7.24 (m, 3 H), 7.09 (d, J = 7.5
Hz, 1 H), 2.42 (s, 3 H), 2.31 (s, 3 H), 2.24 (t, J = 6.8 Hz, 2 H), 1.35–
1.29 (m, 2 H), 0.73 (t, J = 7.3 Hz, 3 H).
13C NMR (100 MHz, CDCl3): δ (major isomer) = 181.2, 139.6,
136.4, 131.3, 129.3, 128.1, 125.7, 95.8, 82.3, 24.0, 22.8, 22.1, 21.3,
13.6; δ (minor isomer) = 182.3, 140.1, 133.7, 132.5, 130.2, 128.6,
125.1, 88.4, 82.4, 27.8, 22.4, 21.5, 19.2, 13.1.
MS (ESI+): m/z = 301.4, 282.2, 278.1, 276.1, 141.9, 139.9, 111.0.
HRMS (ESI): m/z [M + H]+ calcd for C17H23NCl: 276.1519; found:
276.1520.
N-[1-(2-Methoxyphenyl)propylidene]pent-1-yn-1-amine (25a)
Yellow oil; yield: 100 mg (44%); ratio Z/E 64:36.
IR (ATR): 2958, 2929, 2875, 2204, 1600, 1486, 1460, 1435, 1242,
1182, 1017, 751 cm–1.
MS (ESI+): m/z = 202.1, 201.1, 200.1, 111.0.
HRMS (ESI): m/z [M + H]+ calcd for C14H18N: 200.1439; found:
200.1437.
1H NMR (400 MHz, CDCl3): δ (major isomer) = 7.50 (d, J = 7.5 Hz,
1 H), 7.40–7.33 (m, 1 H), 6.99–6.91 (m, 2 H), 3.87 (s, 3 H), 3.03,
(q, J = 7.5 Hz, 2 H), 2.56 (t, J = 6.9 Hz, 2 H), 1.64 (app. sext, J = 7.2
Hz, 2 H), 1.18–1.11 (m, 3 H), 1.06 (t, J = 7.3 Hz, 3 H); δ (minor iso-
mer) = 7.40–7.33 (m, 1 H), 7.20 (d, J = 7.3 Hz, 1 H), 6.99–6.91 (m,
2 H), 3.83 (s, 3 H), 2.74 (q, J = 7.3 Hz, 2 H), 2.27 (t, J = 6.8 Hz, 2
H), 1.39–1.34 (m, 2 H), 1.18–1.11 (m, 3 H), 0.78 (t, J = 7.3 Hz, 3 H).
13C NMR (100 MHz, CDCl3): δ (major isomer) = 186.0, 157.6,
131.3, 129.9, 128.6, 125.0, 120.7, 94.4, 82.0, 55.4, 30.2, 22.8, 22.1,
13.6, 10.6; δ (minor isomer) = 183.4, 155.5, 130.2, 128.4, 127.9,
125.0, 120.2, 88.6, 82.5, 55.5, 33.2, 22.5, 21.6, 13.2, 10.4.
N-[1-(o-Tolyl)ethylidene]oct-1-yn-1-amine (23b)
Yellow oil; yield: 120 mg (50%); ratio Z/E 74:26.
IR (ATR): 2951, 2926, 2195, 1587, 1451, 1365, 1299, 1185, 1074,
1042, 906, 760, 716 cm–1.
1H NMR (400 MHz, CDCl3): δ (major isomer) = 7.42 (d, J = 7.4 Hz,
1 H), 7.31–7.25 (m, 3 H), 2.62 (t, J = 6.9 Hz, 2 H), 2.65 (s, 3 H),
2.48 (s, 3 H), 1.68–1.48 (m, 3 H), 1.36–1.28 (m, 3 H), 1.26–1.14 (m,
2 H), 0.94 (t, J = 6.2 Hz, 3 H); δ (minor isomer) = 7.31–7.25 (m, 3
H), 7.09 (d, J = 7.2 Hz, 1 H), 2.42 (s, 3 H), 2.31 (s, 3 H), 2.27 (t, J
= 6.7 Hz, 2 H), 1.74–1.48 (m, 3 H), 1.36–1.28 (m, 3 H), 1.26–1.14
(m, 2 H), 0.88 (t, J = 7.2 Hz, 3 H).
13C NMR (100 MHz, CDCl3): δ (major isomer) = 181.1, 140.1,
136.1, 131.3, 129.3, 128.1, 125.6, 96.1, 82.2, 31.4, 29.4, 28.7, 24.0,
22.6, 21.1, 20.1, 14.1; δ (minor isomer) = 182.2, 140.1, 133.7,
130.2, 128.6, 125.6, 125.1, 88.7, 82.3, 31.4, 29.0, 28.1, 27.8, 22.5,
19.4, 19.2, 14.1.
MS (ESI+): m/z = 232.1, 231.1, 230.1, 149.0, 111.0.
HRMS (ESI): m/z [M + H]+ calcd for C15H20NO: 230.1545; found:
230.1543.
N-[1-(2-Methoxyphenyl)propylidene]oct-1-yn-1-amine (25b)
Yellow oil; yield: 142 mg (52%); ratio Z/E 62:38.
IR (ATR): 2951, 2929, 2853, 2201, 1603, 1482, 1457, 1429, 1239,
1178, 1128, 1020, 944, 751 cm–1.
MS (ESI+): m/z = 244.2, 243.1, 242.1, 112.0, 111.0.
1H NMR (400 MHz, CDCl3): δ (major isomer) = 7.50 (d, J = 7.5 Hz,
1 H), 7.40–7.33 (m, 1 H), 6.99–6.91 (m, 2 H), 3.85 (s, 3 H), 3.03 (q,
HRMS (ESI): m/z [M + H]+ calcd for C17H24N: 242.1909; found:
242.1907.
© Georg Thieme Verlag Stuttgart · New York
Synthesis 2012, 44, 1491–1500

1498
A. Laouiti et al.
SPECIAL TOPIC
J = 7.5 Hz, 2 H), 2.58 (t, J = 6.9 Hz, 2 H), 1.64–1.45 (m, 3 H), 1.34–
1.25 (m, 3 H), 1.23–1.11 (m, 5 H), 0.92 (t, J = 6.8 Hz, 3 H); δ (minor
isomer) = 7.40–7.33 (m, 1 H), 7.20 (d, J = 7.4 Hz, 1 H), 6.99–6.91
(m, 2 H), 3.83 (s, 3 H), 2.74 (q, J = 7.3 Hz, 2 H), 2.28 (t, J = 6.8 Hz,
2 H), 1.64–1.45 (m, 3 H), 1.34–1.25 (m, 3 H), 1.23–1.11 (m, 5 H),
0.87 (t, J = 7.2 Hz, 3 H).
13C NMR (100 MHz, CDCl3): δ (major isomer) = 185.9, 157.6,
131.3, 129.2, 128.6, 120.6, 111.0, 94.6, 81.9, 55.4, 31.4, 30.2, 29.3,
28.6, 22.6, 20.1, 14.1, 10.6; δ (minor isomer) = 183.4, 155.5, 130.2,
128.4, 128.0, 120.2, 111.1, 88.8, 82.4, 55.5, 33.2, 31.4, 29.1, 28.3,
22.6, 19.6, 14.1, 10.5.
2-(4-tert-Butylphenyl)-N-[1-(2,3-dimethylphenyl)pentyli-
dene]ethyn-1-amine (30)
Yellow solid; yield: 197 mg (57%); ratio Z/E 42:58; mp 69 °C.
IR (ATR): 2954, 2922, 2858, 2189, 1570, 1450, 1266, 1109, 1039,
1019, 832, 792, 756, 729, 557 cm–1.
1H NMR (400 MHz, CDCl3): δ (major isomer) = 7.45–7.40 (m, 2
H), 7.28–7.25 (m, 1 H), 7.23–7.16 (m, 2 H), 7.07 (d, J = 8.1 Hz, 2
H), 2.78 (t, J = 7.6 Hz, 2 H), 2.35 (s, 6 H), 1.70 (app. quint, J = 7.6
Hz, 2 H), 1.49–1.40 (m, 2 H), 1.30 (s, 9 H), 0.97 (t, J = 7.3 Hz, 3 H);
δ (minor isomer) = 7.45–7.40 (m, 2 H), 7.28–7.25 (m, 1 H), 7.23–
7.16 (m, 2 H), 6.99 (d, J = 7.2 Hz, 2 H), 3.07 (t, J = 7.8 Hz, 2 H),
2.22 (s, 6 H), 1.64–1.57 (m, 2 H), 1.49–1.40 (m, 2 H), 1.37 (s, 9 H),
0.96 (t, J = 7.3 Hz, 3 H).
13C NMR (100 MHz, CDCl3): δ (major isomer) = 187.1, 150.8,
140.1, 137.3, 132.9, 131.3, 130.3, 125.6, 125.2, 123.3, 121.6, 90.5,
88.2, 41.2, 34.8, 31.3, 28.2, 22.7, 20.4, 16.8, 14.0; δ (minor isomer) =
187.5, 151.1, 139.8, 138.0, 134.4, 131.1, 130.9, 125.5, 125.4, 125.3,
121.7, 93.7, 89.1, 38.6, 34.9, 31.3, 28.6, 23.0, 20.6, 17.0, 13.9.
MS (ESI+): m/z = 274.2, 273.2, 272.2, 141.9, 111.0.
HRMS (ESI): m/z [M + H]+ calcd for C18H26NO: 272.2014; found:
272.2016.
(E)-N-(2,2-Dimethyl-1-phenylpropylidene)pent-1-yn-1-amine
(26a)
Yellow oil; yield: 20 mg (9%).
IR (ATR): 2964, 2926, 2866, 2204, 1587, 1476, 1454, 1359, 1229,
1204, 988, 770, 710, 691 cm–1.
1H NMR (300 MHz, CDCl3): δ = 7.31–7.28 (m, 3 H), 7.02 (d, J =
8.3 Hz, 2 H), 2.11 (t, J = 6.8 Hz, 2 H), 1.20–1.14 (obs. m, 2 H), 1.13
(obs. s, 9 H), 0.59 (t, J = 7.3 Hz, 3 H).
13C NMR (75 MHz, CDCl3): δ = 191.6, 138.7, 128.0, 127.9, 126.4,
90.4, 82.4, 40.5, 28.4, 22.4, 21.5, 13.1.
MS (ESI+): m/z = 347.3, 346.3.
HRMS (ESI): m/z [M + H]+ calcd for C25H32N: 346.2535; found:
346.2536.
N-[1-(2,3-Dimethylphenyl)pentylidene]-2-(4-methoxyphe-
nyl)ethyn-1-amine (31)
Yellow oil; yield: 186 mg (58%); ratio Z/E 42:58.
IR (ATR): 2955, 2929, 2870, 2360, 2189, 1606, 1506, 1456, 1284,
1244, 1170, 1104, 1027, 829, 783, 731, 532 cm–1.
MS (ESI+): m/z = 229.1, 228.1, 145.1.
HRMS (ESI): m/z [M + H]+ calcd for C16H22N: 228.1752; found:
228.1751.
1H NMR (300 MHz, CDCl3): δ (major isomer) = 7.23–7.15 (m, 3
H), 7.05 (d, J = 8.7 Hz, 2 H), 6.76 (d, J = 8.7 Hz, 2 H), 3.76 (s, 3 H),
2.76 (t, J = 7.9 Hz, 2 H), 2.35 (s, 3 H), 2.34 (s, 3 H), 1.74–1.58 (m,
2 H), 1.51–1.40 (m, 2 H), 0.97 (t, J = 7.3 Hz, 3 H); δ (minor isomer) =
7.44 (d, J = 8.6 Hz, 2 H), 7.23–7.15 (m, 2 H), 6.99 (d, J = 7.0 Hz, 1
H), 6.90 (d, J = 8.6 Hz, 2 H), 3.83 (s, 3 H), 3.07 (t, J = 7.6 Hz, 2 H),
2.21 (s, 6 H), 1.74–1.58 (m, 2 H), 1.51–1.40 (m, 2 H), 0.95 (t, J =
7.2 Hz, 3 H).
13C NMR (75 MHz, CDCl3): δ (major isomer) = 186.2, 159.2,
140.0, 137.2, 134.4, 133.0, 130.2, 125.5, 123.3, 116.6, 113.8, 90.0,
88.0, 55.2, 41.1, 28.2, 22.6, 20.4, 16.8, 13.9; δ (minor isomer) =
186.7, 159.4, 139.7, 137.9, 134.1, 132.9, 130.8, 125.5, 125.3, 116.8,
114.1, 93.5, 88.6, 55.3, 38.4, 28.5, 22.9, 20.6, 17.0, 13.9.
(E)-N-(2,2-Dimethyl-1-phenylpropylidene)oct-1-yn-1-amine
(26b)
Yellow oil; yield: 30 mg (11%).
IR (ATR): 2950, 2923, 2852, 2201, 1582, 1475, 1455, 1357, 1234,
1203, 986, 769 cm–1.
1H NMR (400 MHz, CDCl3): δ = 7.41–7.35 (m, 3 H), 7.11 (d, J =
6.8 Hz, 2 H), 2.22 (t, J = 6.8 Hz, 2 H), 1.27–1.15 (obs. m, 4 H), 1.20
(obs. s, 9 H), 1.15–1.05 (m, 4 H), 0.86 (t, J = 7.2 Hz, 3 H).
13C NMR (100 MHz, CDCl3): δ = 191.5, 138.8, 128.0, 127.9, 126.4,
90.7, 82.3, 40.5, 31.4, 29.3, 29.0, 28.1, 22.5, 19.5, 14.1.
MS (ESI+): m/z = 301.1, 271.2, 270.2, 139.9, 124.0, 111.0.
MS (ESI+): m/z = 321.2, 320.2.
HRMS (ESI): m/z [M + H]+ calcd for C19H28N: 270.2222; found:
270.2221.
HRMS (ESI): m/z [M + H]+ calcd for C22H26NO: 320.2014; found:
320.2014.
N-[1-(2,3-Dimethylphenyl)pentylidene]-2-phenylethyn-1-amine
N-[1-(2,3-Dimethylphenyl)pentylidene]-2-(4-fluorophe-
nyl)ethyn-1-amine (32)
Pale yellow solid; yield: 160 mg (52%); ratio Z/E 40:60; mp 65 °C.
(29)
Yellow oil; yield: 136 mg (47%); ratio Z/E 41:59.
IR (ATR): 2955, 2927, 2870, 2360, 2341, 2184, 1576, 1488, 1455,
1383, 1266, 1024, 989, 786, 753, 686, 521 cm–1.
IR (ATR): 2949, 2929, 2869, 2195, 1604, 1580, 1503, 1464, 1408,
1379, 1346, 1229, 1217, 1168, 1155, 1093, 1012, 986, 836, 782,
736, 604, 528, 474 cm–1.
1H NMR (300 MHz, CDCl3): δ (major isomer) = 7.22–7.14 (m, 3
H), 7.08–7.02 (m, 2 H), 6.93–6.87 (m, 2 H), 2.76 (t, J = 7.9 Hz, 2
H), 2.33 (s, 6 H), 1.71 (app. quint, J = 7.1 Hz, 2 H), 1.44 (app. sext,
J = 7.2 Hz, 2 H), 0.95 (t, J = 7.3 Hz, 3 H); δ (minor isomer) = 7.47–
7.42 (m, 2 H), 7.22–7.14 (m, 2 H), 7.08–7.02 (m, 1 H), 6.97 (d, J =
7.0 Hz, 2 H), 3.05 (t, J = 7.6 Hz, 2 H), 2.20 (s, 6 H), 1.62–1.53 (m,
2 H), 1.44 (app. sext, J = 7.2 Hz, 2 H), 0.93 (t, J = 7.1 Hz, 3 H).
13C NMR (75 MHz, CDCl3): δ (major isomer) = 187.8, 162.2 (J =
247.0 Hz), 140.0, 137.4, 133.3 (J = 8.2 Hz), 132.8, 130.4, 125.6,
123.3, 120.6 (J = 3.6 Hz), 115.4 (J = 21.8 Hz), 90.6, 86.9, 41.2, 28.2,
22.6, 20.4, 16.8, 14.0; δ (minor isomer) = 188.0, 162.3 (J = 247.4
Hz), 139.6, 138.0, 134.4, 133.2 (J = 8.2 Hz), 131.0, 125.5, 125.4,
120.8 (J = 3.6 Hz), 115.7 (J = 21.8 Hz), 92.4, 89.1, 38.6, 28.6, 23.0,
20.6, 17.0, 13.9.
1H NMR (400 MHz, CDCl3): δ (major isomer) = 7.41–7.32 (m, 2
H), 7.24–7.18 (m, 4 H), 7.15–7.13 (m, 2 H), 2.80 (t, J = 7.6 Hz, 2
H), 2.36 (s, 6 H), 1.72 (app. quint, J = 7.5 Hz, 2 H), 1.51–1.42 (m,
2 H), 0.99 (t, J = 7.4 Hz, 3 H); δ (minor isomer) = 7.51 (d, J = 7.3
Hz, 2 H), 7.24–7.18 (m, 4 H), 7.01 (d, J = 7.2 Hz, 2 H), 3.09 (t, J =
7.8 Hz, 2 H), 2.24 (s, 6 H), 1.66–1.58 (m, 2 H), 1.51–1.42 (m, 2 H),
0.97 (t, J = 7.4 Hz, 3 H).
13C NMR (100 MHz, CDCl3): δ (major isomer) = 187.6, 140.0,
137.4, 132.8, 131.5, 131.3, 128.4, 128.2, 125.6, 125.5, 123.3, 90.9,
88.1, 41.2, 28.2, 22.6, 20.4, 16.8, 14.0; δ (minor isomer) = 188.0,
139.7, 138.0, 134.4, 130.9, 130.3, 127.8, 127.6, 125.3, 124.7, 124.6,
93.5, 89.5, 38.6, 28.6, 23.0, 20.6, 17.0, 13.9.
MS (ESI+): m/z = 291.2, 290.2.
HRMS (ESI): m/z [M + H]+ calcd for C21H24N: 290.1909; found:
290.1908.
Synthesis 2012, 44, 1491–1500
© Georg Thieme Verlag Stuttgart · New York

SPECIAL TOPIC
Efficient and General Synthesis of Ynimines
1499
19F NMR (282 MHz, CDCl3): δ (major isomer) = –112.2 (m); δ (mi-
nor isomer) = –112.1 (m).
13C NMR (100 MHz, CDCl3): δ (major isomer) = 185.8, 140.5,
137.2, 132.7, 130.2, 125.6, 123.1, 87.6, 87.1, 71.1, 69.8, 68.6, 66.6,
41.0, 28.1, 22.6, 20.4, 16.7, 14.0; δ (minor isomer) = 185.7, 139.9,
137.9, 134.3, 130.7, 125.4, 125.3, 93.2, 86.4, 71.4, 69.9, 69.0, 66.8,
38.4, 28.4, 23.0, 20.6, 17.0, 13.9.
MS (ESI+): m/z = 307.2, 271.3, 221.0, 149.0 142.0, 140.0.
HRMS (ESI): m/z [M + H]+ calcd for C21H23NF: 308.1815; found:
308.1812.
MS (ESI+): m/z = 400.2, 399.2, 398.2, 397.2, 395.2, 124.1.
HRMS (ESI): m/z [M]+ calcd for C25H27NFe: 397.1493; found:
397.1509.
N-[1-(2,3-Dimethylphenyl)pentylidene]-2-(o-tolyl)ethyn-1-
amine (33)
Yellow solid; yield: 149 mg (49%); ratio Z/E 62:38; mp 48 °C.
IR (ATR): 2949, 2925, 2870, 2357, 2338, 2179, 1579, 1456, 1377,
1169, 1129, 986, 781, 758, 737, 716, 635, 444 cm–1.
Acknowledgment
1H NMR (400 MHz, CDCl3): δ (major isomer) = 7.27–7.16 (m, 4
H), 7.14–7.07 (m, 2 H), 6.98 (d, J = 7.9 Hz, 1 H), 2.79 (t, J = 7.7 Hz,
2 H), 2.34 (s, 3 H), 2.23 (s, 3 H), 1.93 (s, 3 H), 1.74 (app. quint, J =
7.5 Hz, 2 H), 1.54–1.40 (m, 2 H), 0.99 (t, J = 7.3 Hz, 3 H); δ (minor
isomer) = 7.49 (d, J = 7.2 Hz, 1 H), 7.27–7.16 (m, 4 H), 7.14–7.07
(m, 2 H), 3.10 (t, J = 7.9 Hz, 2 H), 2.54 (s, 3 H), 2.37 (s, 6 H), 1.66–
1.59 (m, 2 H), 1.54–1.40 (m, 2 H), 0.96 (t, J = 7.3 Hz, 3 H).
The authors thank the CNRS, the Universities of Versailles and
Monastir, the ANR (project DYNAMITE ANR-2010-BLAN-704)
and the CMCU/PHC Utique (grant 10G1025) for financial support.
A.L. thanks the University of Monastir and the CMCU for a gradu-
ate fellowship. K.J. acknowledges the Ministère de la Recherche for
a graduate fellowship. We are indebted to Mrs Estelle Galmiche
(Lavoisier Institute) for her help with mass spectrometry analyses.
13C NMR (100 MHz, CDCl3): δ (major isomer) = 187.3, 140.4,
139.9, 137.5, 132.5, 132.2, 130.2, 129.2, 127.8, 125.8, 125.5, 124.2,
123.1, 94.5, 86.5, 41.3, 28.1, 22.7, 20.3, 20.1, 16.5, 14.0; δ (minor
isomer) = 187.3, 139.8, 139.5, 138.0, 134.4, 131.9, 130.9, 129.5,
128.0, 125.7, 125.4, 124.5, 123.1, 93.3, 92.4, 38.7, 28.5, 23.1, 21.1,
20.6, 17.0, 13.9.
Supporting Information for this article is available online at
http://www.thieme-connect.com/ejournals/toc/synthesis.omnorinaIftngonimSornipfrotunIagitSourp.
References
MS (ESI+): m/z = 305.2, 304.2.
(1) Glaser, C. Justus Liebigs Ann. Chem. 1870, 154, 137.
(2) (a) Nast, R.; Pfab, W. Chem. Ber. 1956, 89, 415. (b) Blake,
D.; Calvin, G.; Coates, G. E. Proc. Chem. Soc., London
1959, 396. (c) Sazonova, V. A.; Ya, N. K. Zh. Obshch.
Khim. 1956, 26, 1876; Chem. Abstr. 1957, 51, 4981c.
(d) Stephens, R. D.; Castro, C. E. J. Org. Chem. 1963, 28,
3313. (e) Atkinson, R. E.; Curtis, R. F.; Taylor, J. A.
J. Chem. Soc. C 1967, 578. (f) Owsley, D. C.; Castro, C. E.
Org. Synth. Coll. Vol. VI; John Wiley & Sons: London,
1988, 916. (g) Ito, H.; Arimoto, K.; Sensui, H.-o.; Hosomi,
A. Tetrahedron Lett. 1997, 38, 3977. (h) Chui, S. S. Y.; Ng,
M. F. Y.; Che, C.-M. Chem.–Eur. J. 2005, 11, 1739.
(i) Buckley, B. R.; Dann, S. E.; Harris, D. P.; Heanay, H.;
Stubbs, E. C. Chem. Commun. 2010, 46, 2274.
(3) Normant, J. F. Synthesis 1972, 63.
(4) Chodkiewicz, W.; Cadiot, P. C. R. Acad. Sci. 1955, 241,
1055.
(5) For general references on the oxidation of organocopper
reagents, see: (a) Surry, D. S.; Spring, D. A. Chem. Soc. Rev.
2006, 35, 218. (b) Aves, S. J.; Spring, D. R. The Chemistry
of Functional Groups, In The Chemistry of Organocopper
Compounds, Vol. 24; Rappoport, Z.; Marek, I., Eds.; John
Wiley & Sons Ltd: Chichester, 2009, 585.
HRMS (ESI): m/z [M + H]+ calcd for C22H26N: 304.2065; found:
304.2058.
N-[1-(2,3-Dimethylphenyl)pentylidene]-2-(2-methoxyphe-
nyl)ethyn-1-amine (34)
Yellow oil; yield: 153 mg (48%); ratio Z/E 55:45.
IR (ATR): 2956, 2929, 2872, 2364, 2332, 2186, 1600, 1573, 1490,
1456, 1433, 1269, 1241, 1180, 1121, 1050, 1024, 908, 785, 750,
730 cm–1.
1H NMR (300 MHz, CDCl3): δ (major isomer) = 7.22–7.00 (m, 4
H), 6.95–6.75 (m, 2 H), 6.66 (d, J = 8.0 Hz, 1 H), 3.80 (s, 3 H), 2.65
(t, J = 7.4 Hz, 2 H), 2.22 (s, 6 H), 1.63–1.48 (m, 2 H), 1.40–1.29 (m,
2 H), 0.84 (t, J = 7.6 Hz, 3 H); δ (minor isomer) = 7.35 (d, J = 7.4
Hz, 1 H), 7.22–7.00 (m, 3 H), 6.95–6.75 (m, 2 H), 6.71 (d, J = 7.6
Hz, 1 H), 3.80 (s, 3 H), 3.00 (t, J = 7.7 Hz, 2 H), 2.12 (s, 6 H), 1.63–
1.48 (m, 2 H), 1.40–1.29 (m, 2 H), 0.83 (t, J = 7.2 Hz, 3 H).
13C NMR (75 MHz, CDCl3): δ (major isomer) = 186.5, 159.5,
140.1, 137.2, 133.4, 133.1, 130.1, 129.1, 125.5, 123.3, 120.3, 113.9,
110.7, 94.7, 84.5, 55.6, 41.2, 28.2, 22.6, 20.4, 16.8, 13.9; δ (minor
isomer) = 187.4, 159.3, 139.8, 137.9, 134.5, 133.2, 130.8, 129.4,
125.5, 125.3, 120.6, 113.8, 110.6, 93.7, 89.3, 55.8, 38.6, 28.5, 23.0,
20.6, 17.0, 13.9.
(6) Yamamoto, H.; Maruoka, K. J. Org. Chem. 1980, 45, 2739.
(7) Iwao, M.; Reed, J. N.; Snieckus, V. J. Am. Chem. Soc. 1982,
104, 5531.
(8) (a) Alberti, A.; Canè, F.; Dembech, P.; Lazzari, D.; Ricci,
A.; Seconi, G. J. Org. Chem. 1996, 61, 1677. (b) Canè, F.;
Brancaleoni, D.; Dembech, P.; Ricci, A.; Seconi, G.
Synthesis 1997, 545.
MS (ESI+): m/z = 321.2, 320.2.
HRMS (ESI): m/z [M + H]+ calcd for C22H26NO: 320.2014; found:
320.2016.
N-[1-(2,3-Dimethylphenyl)pentylidene]-2-(ferrocenyl)ethynyl-
1-amine (35)
Orange oil; yield: 246 mg (62%); ratio Z/E 38:62.
(9) (a) del Amo, V.; Dubbaka, S. R.; Krasovskiy, A.; Knochel,
P. Angew. Chem. Int. Ed. 2006, 45, 7838. (b) Boudet, N.;
Dubbaka, S. R.; Knochel, P. Org. Lett. 2008, 10, 1715.
(c) Kienle, M.; Dubbaka, S. R.; del Amo, V.; Knochel, P.
Synthesis 2007, 1272. (d) Kienle, M.; Dunst, C.; Knochel, P.
Org. Lett. 2009, 11, 5158.
(10) Jouvin, K.; Heimburger, J.; Evano, G. Chem. Sci. 2012, 3,
756.
(11) (a) Coste, A.; Karthikeyan, G.; Couty, F.; Evano, G. Angew.
Chem. Int. Ed. 2009, 48, 4381. (b) Coste, A.; Couty, F.;
Evano, G. Org. Lett. 2009, 11, 4454. (c) Jouvin, K.; Couty,
IR (ATR): 2955, 2927, 2870, 2361, 2341, 2189, 1576, 1456, 1411,
1383, 1264, 1105, 1069, 1023, 1000, 887, 816, 782, 752, 724, 492
cm–1.
1H NMR (400 MHz, CDCl3): δ (major isomer) = 7.24–7.12 (m, 2
H), 6.99 (d, J = 7.1 Hz, 1 H), 4.16 (s, 2 H), 4.14 (s, 2 H), 4.02 (s, 5
H), 2.74 (t, J = 7.6 Hz, 2 H), 2.41 (s, 3 H), 2.27 (s, 3 H), 1.70 (app.
quint, J = 7.5 Hz, 2 H), 1.46 (app. sext, J = 7.4 Hz, 2 H), 0.98 (t, J =
7.3 Hz, 3 H); δ (minor isomer) = 7.24–7.12 (m, 3 H), 4.49 (s, 2 H),
4.30 (s, 2 H), 4.27 (s, 5 H), 3.03 (t, J = 7.7 Hz, 2 H), 2.35 (s, 6 H),
1.63 (app. quint, J = 7.5 Hz, 2 H), 1.46 (app. sext, J = 7.4 Hz, 2 H),
1.00 (t, J = 7.2 Hz, 3 H).
© Georg Thieme Verlag Stuttgart · New York
Synthesis 2012, 44, 1491–1500

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A. Laouiti et al.
SPECIAL TOPIC
F.; Evano, G. Org. Lett. 2010, 12, 3272. (d) Jouvin, K.;
Evano, G. Chim. Oggi 2011, 29, 31. (e) Fadel, A.; Legrand,
F.; Evano, G.; Rabasso, N. Adv. Synth. Catal. 2011, 353,
263. (f) Laouiti, A.; Rammah, M. M.; Rammah, M. B.;
Marrot, J.; Couty, F.; Evano, G. Org. Lett. 2012, 14, 6.
(13) For reactions involving ynimines, see: (a) David, W. M.;
Kerwin, S. M. J. Am. Chem. Soc. 1997, 119, 1464.
(b) Hoffner, J.; Schottelius, M. J.; Feichtinger, D.; Chen, P.
J. Am. Chem. Soc. 1998, 120, 376. (c) Feng, L.; Kumar, D.;
Kerwin, S. M. J. Org. Chem. 2003, 68, 2234. (d) Feng, L.;
Kerwin, S. M. Tetrahedron Lett. 2003, 44, 3463. (e) Feng,
L.; Zhang, A.; Kerwin, S. M. Org. Lett. 2006, 8, 1983.
(14) Würthwein, E.-U.; Weigmann, R. Angew. Chem., Int. Ed.
Engl. 1987, 26, 923.
(12) For reviews, see: (a) Evano, G.; Coste, A.; Jouvin, K.
Angew. Chem. Int. Ed. 2010, 49, 2840. (b) DeKorver, K. A.;
Li, H.; Lohse, A. G.; Hayashi, R.; Lu, Z.; Zhang, Y.; Hsung,
R. P. Chem. Rev. 2010, 110, 5064.
Synthesis 2012, 44, 1491–1500
© Georg Thieme Verlag Stuttgart · New York