Pd(OAc)2/dppf as an efficient and highly active catalyst for the allylation of amines, alcohols and carboxylic acids with 1-phenyl-1-propyne

Article abstract of DOI:10.1016/j.tet.2011.02.008

Pd(OAc)₂/1,1′-bis(diphenylphosphino)ferrocene as an efficient, highly active catalyst for the allylation of amines, alcohols and carboxylic acids with 1-phenyl-1-propyne has been developed. The effect of various reaction parameters, such as ligand, time, solvent, temperature, metal: ligand ratio and catalyst concentration on yields of the product were investigated. The optimized procedure works well under mild operating conditions and permits rapid generation of a library for various allylated products.

Full text of DOI:10.1016/j.tet.2011.02.008

Tetrahedron 67 (2011) 2414e2421
Contents lists available at ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Pd(OAc)2/dppf as an efficient and highly active catalyst for the allylation
of amines, alcohols and carboxylic acids with 1-phenyl-1-propyne
*
Yogesh S. Wagh, Dinesh N. Sawant, Pawan J. Tambade, Kishor P. Dhake, Bhalchandra M. Bhanage
Department of Chemistry, Institute of Chemical Technology (Autonomous), N. Parekh Marg, Matunga, Mumbai 400019, Maharashtra, India
a r t i c l e i n f o
a b s t r a c t
Pd(OAc)2/1,10-bis(diphenylphosphino)ferrocene as an efficient, highly active catalyst for the allylation of
amines, alcohols and carboxylic acids with 1-phenyl-1-propyne has been developed. The effect of various
reaction parameters, such as ligand, time, solvent, temperature, metal: ligand ratio and catalyst con-
centration on yields of the product were investigated. The optimized procedure works well under mild
operating conditions and permits rapid generation of a library for various allylated products.
Ó 2011 Elsevier Ltd. All rights reserved.
Article history:
Received 23 September 2010
Received in revised form 3 January 2011
Accepted 1 February 2011
Available online 23 February 2011
Keywords:
Palladium
Allylation
Pronucleophiles
Amination
Alkynes
1. Introduction
limits their applications. Also, generality of the protocol has not
been explored with respect to the structural and electronic varia-
Allylation of N- and O-pronucleophiles is one of the most im-
portant protocol for synthesis of allyl amines, allyl ethers and allyl
esters rendering their applications in organic synthesis,1,2 biological
systems,3 natural products4 and perfumery industry.5 These ally-
lated products can be synthesized by palladium catalyzed allylation
of N- and O-pronucleophiles with allenes,6 allylic alcohols7 and
their derivatives such as ether,8 acetate9 and carbonate10 by sub-
stitution reaction. Among the various reported methodologies,
allylation using internal alkynes is considerably important from
synthetic point of view. Yamamoto and co-workers reported in-
termolecular allylic amination of internal alkynes with amines us-
ing palladium/carboxylic acid catalyst using monophosphine
ligands.11 However, very few reports can be found on allylic
alkoxylation and allylic carboxylation reactions.12 The major
drawback of allylation reactions with O-pronucleophiles is that it
requires longer reaction time (1e3 days) and high catalyst con-
centration. A partial solution to decrease reaction time, Yamamoto
and co-workers reported allylation of some pronucleophiles with
alkynes under microwave irradiation condition in the absence of
solvent.13 Many of these reports on the allylation using alkynes
have drawbacks like requirement of high catalyst concentration,
longer reaction time and lower substrate compatibility, which
tion in pronucleophiles. To the best of our knowledge till date, the
various bisphosphine ligands are not yet explored for the present
methodology and no report exist on a single catalytic system, which
can effectively catalyze variety of allylation reactions of amines or
alcohols or carboxylic acids. Therefore, there is need to develop
a truly catalytic, active and viable protocol for the allylation of
amines, alcohols and carboxylic acids, which can operate under
milder reaction conditions.
As part of our interest in amination reactions,14 we herein report
a facile protocol for the allylation of amines or alcohols or carboxylic
acids with 1-phenyl-1-propyne using Pd(OAc)2/1,10-bis(diphenyl-
phosphino)ferrocene [Pd(OAc)2/dppf] as a highly active catalytic
system, which functions under mild reaction conditions (Scheme 1).
Excellent yield of desired allylated products was obtained by using
only 2.5 mol % of the catalyst under optimized reaction conditions.
2. Result and discussion
2.1. Allylation of aromatic and aliphatic amines
The reaction of N-methyl aniline (1) with 1-phenyl-1-propyne
(2) in the presence of Pd(OAc)2/dppf as a catalyst was selected as
a model reaction (Scheme 2) and influence of various reaction pa-
rameters, such as type of ligand, time, solvent, temperature and
catalyst concentration were examined (Tables 1 and 2).
* Corresponding author. Tel.: þ91 22 2414 5616; fax: þ91 22 2414 5614; e-mail
address: bhalchandra_bhanage@yahoo.com (B.M. Bhanage).
0040-4020/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2011.02.008

Y.S. Wagh et al. / Tetrahedron 67 (2011) 2414e2421
2415
R
The nature of ligand plays a key role on activity and selectivity of
reaction and hence, various phosphine ligands were screened (see
Table 1). In order to investigate the influence of ligand on allylation
of amine, the reaction of 1 with 2 in the presence of Pd(OAc)2
(5 mol %) as a catalyst precursor and toluene as a solvent under
reflux conditions was carried out with different phosphine ligands.
NH
R'
R
Ph
Ph
N
R'
Pd(OAc) /dppf,
2
PhCOOH
R
O
OH
OH
R
O
Ph
CH
O
3
Toluene, 110 °C
PPh
Ph P
2
PPh
3
2
Ph P
2
PPh
2
PPh PPh
2
2
R
tpp (L )
1
dppe (L )
3
dppp (L )
4
dppm (L )
2
Ph
O
R
R = Alkyl, aryl; R' = H, alkyl, aryl
Scheme 1. Pd(OAc)2/dppf catalyzed allylation of amines/alcohols/carboxylic acids with
internal alkynes.
PPh
2
PPh
Fe
2
O
Ph P
2
PPh
2
PPh
PPh
2
NH
N
Ph
2
Pd(OAc) /ligand
2
xantphos (L )
7
dppb (L )
5
dppf (L )
6
+ H C
Ph
3
PhCO H
2
1
2
3
The activity of each ligand was investigated with respect to time
by continuous monitoring of reaction progress on GC up to 12 h.
The results were also compared with preformed Pd(PPh3)4 complex
Scheme 2. Pd(OAc)2/dppf catalyzed allylic amination of 1-phenyl-1-propyne with N-
methyl aniline.
(Table 1, L1). The catalyst was prepared by interaction of palladium
*
Table 1
precursor Pd(OAc)2 and the ligand (PPh3) in the ratio of 1:4 (Table 1,
L1) and can be compared to preformed catalyst. In comparison to
preformed Pd(PPh3)4 complex, the catalyst prepared in situ was
found to be much more active providing good yield of desired
product. The study was further continued with catalyst prepared in
situ using various bisphosphine ligands. Initially, the ligand 1,1-bis
(diphenylphosphino) methane (dppm) was studied with very low
rate of reaction at earlier stage. However, after 12 h it yielded 65% of
desired product. The results obtained using dppm as a ligand en-
couraged us to examine the effect of other bisphosphine ligands on
the product yield. Then we tried various bisphosphine ligands, such
as dppe, dppp, dppb, dppf and xantphos for allylation of amine. The
results revealed that rate of reaction are much faster when dppe,
dppb and dppf were used as ligands, whereas other ligands showed
poor activity (Table 1). It was observed that dppf (L6) showed ex-
cellent activity with 99% yield of 3 in just 1 h. Thus, Pd(OAc)2/dppf
was chosen as a optimized catalyst for further study.
Effect of phosphine ligands on allylic amination of 1-phenyl-1-propyne with N-
methyl anilinea
Entry
Time (h)
Yieldb (%)
c
L1
L1*d
L2
L3
L4
L5
L6
L7
1
2
3
4
5
1.0
2.0
4.0
8.0
12.0
80
88
95
96
96
53
68
84
92
92
02
21
46
52
65
37
77
88
90
90
14
18
30
42
73
75
81
85
85
88
99
99
99
99
99
39
48
53
59
65
a
Reaction conditions:
1
(1 mmol), 2 (1 mmol), Pd(OAc)2 (5 mol %), ligand
(10 mol %), PhCOOH (10 mol %), toluene (10 mL), temperature (110 ꢀC).
b
GC yield.
Pd(OAc)2/L1 (1:4).
L1*¼ Preformed Pd(PPh3)4.
c
d
Table 2
The effect of various polar and non-polar solvents on allylic
amination was studied to find out the optimum solvent for present
reaction (Table 2, entries 1e8). The non-polar solvents like toluene,
hexane, cyclohexane and xylene were screened. It was observed
that reaction does not proceed in the case of low boiling solvents
like hexane and cyclohexane while high boiling non-polar solvents
like toluene and xylene provides good yield of the product. The
polar solvents like dioxane, THF, DMF and acetonitrile were also
studied, however, they provide comparatively lower yield of the
product (Table 2, entries 5e8). Among all the solvents screened,
toluene was found to furnish excellent yield of product (99%) (Table
2, entry 1). Subsequently, we examined the effect of temperature
ranging from 80 ꢀC to 120 ꢀC on formation of the product (Table 2,
entries 1 and 9e11). It was observed increase in temperature upto
110 ꢀC, increases the yield of product (3) up to 99%. However, fur-
ther increase in temperature to 120 ꢀC has no significant effect on
catalytic activity (Table 2, entry 11).
The effect of catalyst concentration from 1 mol % to 5 mol % of
substrate on allylic amination reaction was examined (Table 2 en-
tries 1, 12 and 13). Initially, the reaction was carried out using
5 mol % of catalyst which offers 99% yield of the desired product 3
(Table 2, entry 1). Hence, we tried to decrease the catalyst con-
centration to make the protocol more economical and performed
the reaction at 2.5 mol % of catalyst and observed 99% yield of
Effect of reaction parameters on the allylic amination of 1-phenyl-1-propyne with N-
methyl anilinea
No.
Solvent
Pd(OAc)2
dppf
Temp (ꢀC)
Yieldb (%)
Effect of solvent
1
2
3
4
5
6
7
8
Toluene
Hexane
Cyclohexane
Xylene
1,4-Dioxane
THF
DMF
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
10
10
10
10
10
10
10
10
110
70
80
140
100
70
140
80
99
00
00
64
40
80
24
62
Acetonitrile
Effect of temperature
9
Toluene
Toluene
Toluene
5.0
5.0
5.0
10
10
10
80
90
120
84
90
99
10
11c
Effect of catalyst concentration
12
13
14
15
Toluene
Toluene
Toluene
Toluene
2.5
1.0
2.5
2.5
5
110
110
110
110
99
40
66
99
2.0
2.5
7.5
a
Reaction conditions: 1 (1 mmol), 2 (1 mmol), PhCOOH (10 mol %), toluene
(4 mL), 1 h.
b
c
GC yield.
Reaction was performed in sealed vial.

2416
Y.S. Wagh et al. / Tetrahedron 67 (2011) 2414e2421
product 3 (Table 2, entry 12). It was observed that further decrease
in catalyst concentration (1 mol %), decreases the yield of desired
product (Table 2, entry 13). The reaction was also performed at
different metal: ligand ratio, i.e., 1:1, 1:2 and 1:3 with 2.5 mol % of
the Pd(OAc)2 (Table 2, entries 12, 14 and 15) where metal: ligand
ratio of 1:2 was found to be best for catalyzing the present allylation
reaction offering 99% yield of desired product 3 (Table 2, entry 12).
Thus, using Pd(OAc)2/dppf as a preferred catalyst, PhCOOH as
a co-catalyst and toluene as a solvent at 110 ꢀC, the allylic amination
of various functionalized aromatic and aliphatic amines with 1-
phenyl-1-propyne (2) was studied (Table 3). The reaction of 2 with
sterically hindered N-substituted, N-phenyl aniline requires com-
paratively more time, providing good yield of the desired product in
6 h (Table 3, entry 2). Aniline on reaction with 2 gives two products,
i.e., mono and diallylated anilines with the selectivity ratio of 90:10
in just 1 h (Table 3, entry 3). The reaction of 2 with aniline having
electron donating and withdrawing group, such as eCH3, eOCH3,
eF, eCl, eNO2, eCF3 and eCN at ortho position provides selectivity
towards monoallylated product with excellent yield (88e98%)
within short period of time (Table 3, entry 4e10). Treatment of 2,4-
difluroaniline with 2 under optimized conditions gives corre-
sponding monoallylated product in 98% yield (Table 3, entry 11).
Anilines having ring activating as well as ring deactivating groups
at meta and para position endows mixture of mono and diallylated
products with excellent selectivity towards monoallylated product.
In case of ortho substituted anilines only monoallylated products
were obtained owing to the steric hindrance of ortho substituent for
diallylation reaction, which is not the case in meta and para
substituted aniline. Reaction of 2 with meta-trifluoromethyl aniline
provides mixture of mono and diallylated products with the ratio of
90:10 (Table 3, entry 12). Treatment of 2 with para-toluedine fur-
nishes excellent yield of corresponding products with 98% yield of
mixture of products in the ratio of 88:12 (Table 3, entry 13). para-
Anisidine also reacts effectively with 2 providing mixture of mono
and diallylated product with the ratio of 85:15 (Table 3, entry 14).
The reaction of para-nitro aniline with 2 preceded 90% yield with
80:20 ratio for mono: diallylated products (Table 3, entry 15). Re-
action of 2 with bulky a-naphthylamine under optimized reaction
conditions gave 96% yield of desired product with excellent selec-
tivity (Table 3, entry 16). Encouraged with the results obtained, we
Table 3
Allylation of aromatic and aliphatic amines with 1-phenyl-1-propynea
Ph
R
R
Pd(OAc) /dppf
2
H C
3
Ph
N
+
NH
1
PhCO H, Toluene,
2
R
R'
R = aryl, alkyl; R' = H, alkyl, aryl
Products (3)
110 °C.
No.
1
Amine (1)
Time (h)
Yieldb (%)
NH
N
Ph
1
99c
Ph
Ph
N
NH
Ph
2
6
80
NH
2
HN
Ph
Ph
N
Ph
3
4
+
1
1
98 (90:10)c
NH
2
HN
HN
HN
Ph
Ph
Ph
96
NH
2
O
98c
O
F
5
6
1
1
NH2
97c
F
NH
2
HN
Ph
Cl
Cl
7
1
96

Y.S. Wagh et al. / Tetrahedron 67 (2011) 2414e2421
Products (3)
2417
Table 3 (continued )
No.
Amine (1)
Time (h)
Yieldb (%)
NH
2
HN
HN
HN
Ph
Ph
Ph
NO
8
4
88c
98c
97
2
NO
2
NH
2
CF
3
CF
9
1
4
3
NH
2
CN
F
CN
F
10
NH2
F
HN
F
Ph
11
12
1
1
98c
NH
2
Ph
+
Ph
Ph
Ph
HN
Ph
N
98 (90:10)c
CF
CF
CF
3
3
3
NH
2
HN
HN
Ph Ph
+
N
N
13
14
1
1
98 (88:12)c
95 (85:15)c
NH
2
Ph
Ph
+
O
O
O
N
NH
2
HN
Ph Ph
+
Ph
15
16
6
1
90 (80:20)c
NO
NO
2
NO
2
2
NH
2
HN
Ph
96c
17
18
1
4
98
N
N
H
Ph
Ph
Ts
Ts
NH
N
(E)
95c
NH
N
Ph
19
1
96
O
O
(continued on next page)

2418
Y.S. Wagh et al. / Tetrahedron 67 (2011) 2414e2421
Products (3)
Table 3 (continued )
No.
Amine (1)
Time (h)
Yieldb (%)
N
20
1
98
NH
Ph
21
2
80
N
Ph
NH
a
Reaction conditions: 1-Phenyl-1-propyne (1 mmol), amine (1 mmol), Pd(OAc)2 (2.5 mol %), dppf (5 mol %), PhCOOH (10 mol %), toluene (4 mL), temperature (110 ꢀC).
Yield on the basis of GC and GCeMS analysis.
Isolated yields.
b
c
tried the reaction of indoline with 2, which endowed remarkable
furnishes 95% yield of cinnamyl acetate within 4 h (Table 4, entry 7).
The allylation of acetic acid and ortho-tolueic acid are studied in the
absence of benzoic acid, to avoid the formation of cinnamyl ben-
zoate as a side product. The reaction of benzoic acid and ortho-
tolueic acid with 2 provided desired products with excellent yield
in 5 h (Table 4, entries 8 and 9). The a,b-unsaturated carboxylic acid
such as cinnamic acid on treatment with 2 gave cinnamyl cinna-
mate as a sole product (Table 4, entry 10).
yield of 98% for monoallylated product in just 1 h (Table 3, entry 17).
The sulfonyl protected aniline, such as N-tosyl-aniline effectively
reacts with 2 providing 95% yield (Table 3, entry 18).
Furthermore, the efficiency of present catalytic system for allylic
amination of aliphatic amines, such as morpholine, di-butyl amine
and di-isopropyl amine with 2 was studied (Table 3, entries 19e21).
Morpholine and di-butyl amine react productively with 2 providing
selectively monoallylated products in 1 h, however, sterically hin-
dered aliphatic amine, such as di-isopropyl amine reacts moder-
ately with 2 providing 80% yield of desired product in 2 h.
Table 4
Allylation of alcohols and carboxylic acids with 1-phenyl-1-propynea
Pd(OAc) /dppf
2
R
+
OH
H C
3
Ph
R
O
Ph
2.2. Allylation of alcohols and carboxylic acids
PhCO H, Toluene,
2
110 °C
Present protocol was extended to the allylation of less nucleo-
philic substrates, such as alcohols and carboxylic acids with 1-
phenyl-1-propyne (2) (Table 4, entries 1e10). Although there are
some reports on such transformations, no single catalytic system
exists, which can effectively catalyze all these mentioned reactions.
In order to illustrate the efficiency of present catalytic system for
allylation of less nucleophilic substrate, initially reaction of benzyl
alcohol (1.2 mmol) and 2 (1 mmol) in the presence of Pd(OAc)2
(2.5 mol %), dppf (5.0 mol %) and benzoic acid (10 mol %) in toluene
was carried out at 110 ꢀC. It was observed that reaction requires
longer time as compared to allylation of amines and provides 96% of
desired product in 12 h (Table 4, entry 1). Substituted benzyl al-
cohol, such as 4-methoxy benzyl alcohol was treated with 2 (Table
4, entry 2), which reacts smoothly and gave 85% yield of expected
product. The reaction of secondary alcohols, such as 1-phenyl
ethanol, benzhydrol and menthol was carried out with 2. It was
observed that 1-phenyl ethanol reacts efficiently and provided 84%
yield of desired product (Table 4, entry 3). However, sterically
hindered and less nucleophilic alcohols, such as benzhydrol and
menthol offered good yields of allylated product with extended
reaction time (Table 4, entries 4e5). The dramatic result was ob-
served when cinnamyl alcohol was allowed to react with 2, the
reaction ensued 98% yield of dicinnamyl ether (Table 4, entry 6),
however, GC and GCeMS analysis of reaction shows complete
consumption of cinnamyl alcohol and only 80% conversion of 2
(which is a limiting reagent), this might be because of homocou-
pling reaction of cinnamyl alcohol. In order to untie this ambiguity,
we attempted the reaction of cinnamyl alcohol in the absence of 2,
which furnishes excellent yield of 96% of homocoupled product of
cinnamyl alcohol within 4 h.
R = alkyl, aryl,
alkyl/ aryl carbonyl
No.
Alcohol/acid
Products
Time Yieldb
(h)
(%)
OH
O
Ph
1
2
3
12
96c
OH
O
Ph
12
4
85
84
O
O
OH
O
Ph
OH
O
O
Ph
Ph
4
5
12
12
84c
88
OH
OH
O
Ph
6
7
4
4
98c
Furthermore, we investigated the effect of aliphatic and aro-
matic carboxylic acids to the present methodology, as normally
they require longer reaction time.12a However, in our case all the
carboxylic acids screened react smoothly with comparatively lower
reaction time. The reaction of acetic acid with 1-phenyl-1-propyne
O
O
95c,d
OH
O
Ph

Y.S. Wagh et al. / Tetrahedron 67 (2011) 2414e2421
2419
Table 4 (continued )
4.3. General procedure for allylation of alcohol/acid
No.
Alcohol/acid
Products
Time Yieldb
In a typical experimental procedure, 2.5 mol % of Pd (OAc)2
(5.6 mg), 5 mol % of 1,1-bis(diphenylphosphino) ferrocene (dppf)
(27.8 mg) and 4 mL toluene were taken in a 25 mL round bottom
flask and stirred under nitrogen for 5 min at room temperature.
Then, 1 mmol 1-phenyl-1-propyne (116 mg), 1.2 mmol alcohol/
carboxylic acid and 10 mol % of benzoic acid (12 mg) were added.
The resulting mixture was then stirred at 110 ꢀC till the consump-
tion of starting material. The progress of reaction was monitored on
GC. The reaction mixture was then cooled to room temperature and
filtered through Celite bed. Filtrate obtained was removed under
reduced pressure and product was purified by column chroma-
tography (silica gel, 60e120 mesh; ethyl acetate/petroleum ether,
05/95) to afford the desired products. All the prepared compounds
were confirmed by GCeMS, 1H and 13C NMR analysis.
(h)
(%)
O
O
O
O
8
5
95c,d
OH
O
Ph
Ph
9
5
5
94d
85
OH
O
O
O
10
OH
O
Ph
a
Reaction conditions: 1-Phenyl-1-propyne (1 mmol), alcohol/acid (1.2 mmol), Pd
(OAc)2 (2.5 mol %), dppf (5 mol %), PhCOOH (10 mol %), toluene (4 mL). temperature
(110 ꢀC).
4.4. Spectral data for selected products
b
Yield on the basis of GC and GCeMS analysis.
Isolated yields.
4.4.1. N-Cinnamyl-N-methyl aniline (Table 3, entry 1). Yield: 99%
(220 mg). Rf (5% EtOAc/pet. ether) 0.54, IR (liquid film) 3063, 3011,
c
d
Reaction without PhCOOH.
1
2928, 1599, 1356, 1216, 965. H NMR (300 MHz, CDCl3, 25 ꢀC):
d
¼7.16e7.34 (m, 7H, Ar), 6.76 (d, J¼7.69 Hz, 2H, Ar), 6.71 (t,
3. Conclusion
J¼7.33 Hz, 1H, Ar), 6.49 (d, J¼16.13 Hz, 1H, CH]CHePh), 6.21 (td,
J¼16.13, 5.49 Hz, 1H, CH2eCH]CH), 4.03 (dd, J¼5.49, 1.46 Hz, 2H,
NeCH2eCH), 2.94 (s, 3H, NeCH3) ppm. 13C NMR (75 MHz, CDCl3,
In conclusion, we have developed a facile and efficient protocol
for the allylation of various amines, alcohols and carboxylic acids
with internal alkyne using Pd(OAc)2/dppf as a highly active catalytic
system. The reaction was optimized with respect to various re-
action parameters and enabled allylation of various electron rich,
electron deficient and sterically hindered amines, alcohols and
carboxylic acids affording excellent yield of desired products at low
catalyst concentration.
25 ꢀC):
d
¼149.75 (NeCq, Ar), 137.08 (Cq, Ar), 131.44 (CH2eCH]CH),
129.37 (2CH, Ar), 128.70 (2CH, Ar), 127.57 (CH, Ar), 126.50 (2CH, Ar),
125.93 (CH]CHeAr), 116.78 (CH, Ar), 112.81 (2CH, Ar), 55.05
(NeCH2eCH), 38.17 (NeCH3) ppm. GCeMS (EI, 70 eV): m/z (%)¼223
(40) [Mþ], 118 (12), 117 (100), 115 (45), 91 (25), 51 (8.9), 44 (15.2).
HRMS (ESIþ) calcd for C16H17N (MHþ): 224.1441, found 224.1444.
4.4.2. N-Cinnamyl-2-methoxyaniline (Table 3, entry 5). Yield: 98%
(234 mg). Rf (5% EtOAc/pet. ether) 0.42. IR (liquid film) 3425, 2927,
2854, 1602, 1356, 1216, 967, 750. 1H NMR (400 MHz, CDCl3, 25 ꢀC):
4. Experimental section
4.1. Materials and methods
d
¼7.22e7.39 (m, 5H, Ar), 6.6e6.89 (m, 5H, (4H, Ar and 1H, CH]
CHePh)), 6.35 (td, J¼15.76, 5.86 Hz, 1H, CH2eCH]CH), 4.42 (br s,
1H, NH), 3.95 (dd, J¼5.5, 1.46 Hz, 2H, HNeCH2eCH), 3.85¼(s, 3H,
Palladium acetate, 1,1-bis(diphenylphosphino) ferrocene, 1-
phenyl-1-propyne, amines and benzoic acid were purchased from
SigmaeAldrich Ltd. with their highest purity available and were
used without further purification. Optimized yields were based on
GC (PerkineElmer, Clarus 400) and GCeMS (Shimadzu QP 2010)
analysis. All the products were known and representative products
were characterized by FTIR (PerkineElmer), 1H NMR (Varian
300 MHz) or (Varian 400 MHz), 13C NMR (Varian 75 MHz), GCeMS
(Shimadzu QP 2010) analysis and HRMS (Bruker daltonics, ESI
micrOTOF-Q). Purity of compounds was determined with the help
GCeMS analysis.
eOCH3). 13C NMR (75 MHz, CDCl3, 25 ꢀC):
d
¼146.92 (Cq, Ar), 138.02
(NeCq, Ar), 136.99 (Cq, Ar), 131.35 (CH2eCH]CH), 128.56 (2CH, Ar),
127.46 (CH, Ar), 127.27 (CH]CHePh), 126.36 (2CH, Ar), 121.34 (CH,
Ar), 116.71 (CH, Ar), 110.24 (CH, Ar), 109.45 (CH, Ar), 55.41 (eOCH3),
45.94 (HNeCH2eCH) ppm. GCeMS (EI, 70 eV): m/z (%)¼239 (43)
[Mþ], 117 (100), 115 (41), 91 (31), 77 (10), 45 (46), 44 (38). HRMS
(ESIþ) calcd for C16C17NO(MHþ): 240.1388, found 240.1387.
4.4.3. N-Cinnamyl-2-fluoroaniline (Table 3, entry 6). Yield: 97%
(220 mg). Rf (5% EtOAc/pet. ether) 0.62. IR (liquid film) 3432, 3027,
2850, 1620, 1516, 1447, 1335, 1114, 966, 743, 693. 1H NMR (400 MHz,
4.2. General procedure for allylation of amines
CDCl3, 25 ꢀC):
d
¼7.18e7.36 (m, 5H, Ar), 6.94e7.0 (m, 2H, Ar), 6.73 (t,
J¼8.8 Hz, 1H, Ar), 6.63 (m, 1H, Ar), 6.6 (d, J¼15.76, 1H, CH]CHePh),
6.28 (td, J¼15.76, 5.5 Hz, 1H, CH2eCH]CH), 4.1 (br s, 1H, NH), 3.93
In a typical experimental procedure, 2.5 mol % of Pd (OAc)2
(5.6 mg), 5 mol % of 1,1-bis(diphenylphosphino) ferrocene (dppf)
(27.8 mg) and 4 mL toluene were taken in 25 mL round bottom
flask and stirred under nitrogen for 5 min at room temperature.
Then, 1 mmol 1-phenyl-1-propyne (116 mg), 1 mmol amine and
10 mol % of benzoic acid (12 mg) were added. The resulting mixture
was then stirred at 110 ꢀC till the consumption of starting material.
The reaction was monitored using GC. After completion of reaction,
the reaction mixture was cooled to room temperature and filtered
through Celite bed. Filtrate obtained was removed under reduced
pressure and product was purified by column chromatography
(silica gel, 60e120 mesh; ethyl acetate/petroleum ether, 05/95) to
afford the desired products. The products are well characterized
with GCeMS, 1H and 13C NMR analysis.
13
(d, J¼5.5, 2H, HNeCH2eCH), C NMR (75 MHz, CDCl3, 25 ꢀC):
d
¼151.93 (FeCq, Ar), 136.77 (Cq, Ar), 136.6 (NeCq, Ar), 131.70
(CH2eCH]CH), 128.61 (2CH, Ar), 127.64 (CH, Ar), 126.56 (CH]
CHePh), 126.40 (2CH, Ar), 124.64 (CH, Ar), 116.84 (CH, Ar), 114.45
(CH, Ar), 112.44 (CH, Ar), 45.74 (HNeCH2eCH) ppm. GCeMS (EI,
70 eV): m/z (%)¼227(33.7) [Mþ], 117 (100), 115 (44), 91 (20), 77 (10).
HRMS (ESIþ) calcd for C15H14NF (MHþ)¼228.1189, found: 228.1183.
4.4.4. N-Cinnamyl-2-(trifluoromethyl)aniline (Table 3, entry 9).
Yield: 98% (218 mg). Rf (5% EtOAc/pet. ether) 0.64. IR (liquid film)
3482, 2926, 2855, 1615, 1521, 1332, 1125, 967, 755. 1H NMR
(400 MHz, CDCl3, 25 ꢀC):
2H, Ar), 6.63 (d, J¼16, 1H, CH]CHePh), 6.31 (td, J¼16, 5.6 Hz, 1H,
d
¼7.23e7.45 (m, 7 H, Ar), 6.61e6.79 (m,

2420
Y.S. Wagh et al. / Tetrahedron 67 (2011) 2414e2421
CH2eCH]CH), 4.59 (br s, 1H, NH), 4.02 (d, J¼4.8 Hz, 2H,
1616, 1595, 1493, 1347, 1166, 967, 867, 750. 1H NMR (300 MHz,
CDCl3, 25 ꢀC):
¼7.42 (d, J¼7.7 Hz, 2H, Ar), 6.98e7.15 (m, 12H, Ar),
13
HNeCH2eCH) ppm. C NMR (75 MHz, CDCl3, 25 ꢀC):
d
¼145.74
d
(NeCq, Ar), 136.67 (Cq, Ar), 133.17 (CH, Ar), 131.94 (CH2eCH]CH),
128.65 (2CH, Ar), 127.75 (CH, Ar), 127.15 (CH, Ar), 126.67 (CF3),
126.46 (2CH, Ar), 125.94 (CH]CHePh), 116.21 (CH, Ar), 113.56 (Cq,
Ar), 112.24 (CH, Ar), 45.63 (NeCH2eCH) ppm. GCeMS (EI, 70 eV):
m/z (%)¼277 (29) [Mþ], 117 (100), 115 (38), 91 (19), 77 (5.5).
6.27 (d, J¼15.76 Hz, 1H, CH]CHePh), 6.0 (m, 1H, CH2eCH]CH),
4.48 (d, J¼6.14 Hz, 2H, HNeCH2eCH), 2.3 (s, 3H, CH3eAr), ppm. 13
C
NMR (75 MHz, CDCl3, 25 ꢀC):
d
¼143.45 (CqeNH, Ar), 139.28
(CqeCH3, Ar), 136.36 (Cq-SO2, Ar), 135.7 (CqeCH]CH, Ar), 133.76
(CH]CHePh), 129.44 (2CH, Ar), 128.93 (4CH, Ar), 128.48 (2CH, Ar),
127.74 (CH, Ar), 127.74 (CH2eCH]CH), 126.42 (2CH, Ar), 124.12 (CH,
Ar), 53.31 (HNeCH2eCH), 21.52 (CH3) ppm. MSeMS (ESI): m/z calcd
for (MþNa): 386.13, found (MþNa): 386.2.
4.4.5. N-Cinnamyl-2,4-difluoroaniline (Table 3, entry 11). Yield: 98%
(244 mg). Rf (5% EtOAc/pet. ether) 0.46. IR (liquid film) 3418, 3027,
2850, 1602, 1517, 1266, 1202, 1102, 960, 746. 1H NMR (400 MHz,
CDCl3, 25 ꢀC):
d
¼7.22e7.38 (m, 7 H, Ar), 6.66e6.83(m, 2H, Ar), 6.63
4.4.10. Cinnamyl-(1,1-diphenyl)-methylether
(Table
4,
entry
(d, J¼16 Hz, 1H, CH]CHePh), 6.26 (d, J¼16 Hz, 1H, CH2eCH]CH),
4). Yield: 84% (252 mg). Rf (5% EtOAc/pet. ether) 0.57. IR (liquid
3.95 (d, J¼3.7 Hz, 2H, HNeCH2eCH). 13C NMR (75 MHz, CDCl3,
film) 3010, 2927, 1600, 1216, 1071, 967, 755. 1H NMR (300 MHz,
25 ꢀC):
d
¼154.51 (FeCq, Ar), 150.58 (FeCq, Ar), 136.77 (Cq, Ar),
CDCl3, 25 ꢀC):
d
¼7.2e7.4 (m, 15H, Ar), 6.6 (d, J¼16.13 Hz, 1H, CH]
133.07 (NeCq, Ar), 131.92 (CH2eCH]CH), 128.73 (2CH, Ar), 127.80
(CH, Ar), 126.49 (3CH, CH]CHePh, Ar), 112.42 (CH, Ar), 110.74 (CH,
Ar), 103.53 (CH, Ar), 46.27 (NeCH2eCH) ppm. GCeMS (EI, 70 eV):
m/z (%)¼245(24) [Mþ], 117 (100), 115 (43), 91 (19). HRMS (ESIþ)
calcd for C15H13NF2 (MHþ): 246.1094, found 246.1089.
CHePh), 6.34 (td, J¼15.76, 5.86 Hz, 1H, CH2eCH]CH), 5.48 (s, 1H,
CHPh2), 4.17 (dd, J¼5.86, 1.1 Hz, 2H, OeCH2eCH) ppm. 13C NMR
(75 MHz, CDCl3, 25 ꢀC):
d
¼142.28 (2Cq, Ar), 136.88 (CqeCH, Ar),
132.39 (CH]CHePh, Ar), 128.63 (2CH, Ar), 128.52 (4CH, Ar), 127.72
(CH, Ar), 127.57 (2CH, Ar), 127.16 (4CH, Ar), 126.59 (2CH, Ar), 126.29
(CH2eCH]CH), 82.75 (Ph2CHeO), 69.46 (OeCH2eCH) ppm.
GCeMS (EI, 70 eV): m/z (%)¼168 (17), 167 (100), 152 (14), 118 (44),
117 (16), 77(11).
4.4.6. N-Cinnamyl-3-(trifluoromethyl)aniline (Table 3, entry 12).
Yield: 88% (244 mg). Rf (5% EtOAc/pet. ether) 0.38. IR (liquid film)
3445, 3020, 2926, 1617, 1495, 1340, 1216, 967, 755. 1H NMR
(300 MHz, CDCl3, 25 ꢀC):
d
¼7.2e7.38 (m, 6H, Ar), 6.94 (d, J¼7.3 Hz,
4.4.11. Dicinnamylether (Table 4, entry 6). Yield: 98% (245 mg). Rf
(5% EtOAc/pet. ether) 0.47. IR (liquid film) 3020, 1602, 1495, 1452,
1H, Ar), 6.84 (s, 1H, Ar), 6.76 (d, J¼8 Hz, 1H, Ar), 6.62 (d, J¼15.76 Hz,
1H, CH]CHePh), 6.27 (td, J¼15.76, 5.5 Hz, 1H, CH2eCH]CH), 4.01
(br s, 1H, NH), 3.39 (d, J¼4.8, 2H, HNeCH2eCH) ppm. 13C NMR
1
1216, 968, 759. H NMR (300 MHz, CDCl3, 25 ꢀC):
d
¼7.2e7.4 (m,
10H, Ar), 6.63 (d, J¼16.13 Hz, 2H, CH]CHePh), 6.32 (td, J¼15.76,
(75 MHz, CDCl3, 25 ꢀC):
d
¼148.21 (NeCq, Ar), 136.7 (Cq, Ar), 132.1
6.23 Hz, 2H, CH2eCH]CH), 4.2 (dd, J¼6.23, 1.1 Hz, 2H, OeCH2eCH)
13
(2C, CH2eCH]CH, CqeCF3),129.72 (CH, Ar),128.69 (2CH, Ar),127.77
(CH, Ar),126.43 (2CH, Ar),126.11 (CH]CHePh),115.96 (CH, Ar),114.0
(CH, Ar), 109.25 (CH, Ar), 45.97 (NeCH2eCH) ppm. GCeMS (EI,
70 eV): m/z (%)¼277 (29) [Mþ], 117 (100), 115 (38), 91 (19), 77 (6).
HRMS (ESIþ) calcd for C16H14NF3 (MNaþ): 300.0976, found 300.0971.
ppm. C NMR (75 MHz, CDCl3, 25 ꢀC):
d¼136.75 (2CqeCH, Ar),
132.62 (2CH]CHePh), 128.59 (4CH, Ar), 127.73 (2CH, Ar), 126.55
(4CH, Ar), 126.07 (2CH2eCH]CH), 70.77 (2 OeCH2eCH) ppm.
GCeMS (EI, 70 eV): m/z (%)¼250 (1) [Mþ], 118 (32), 117 (100), 115
(34), 77 (9).
4.4.7. N,N-Dicinnamyl-3-(trifluoromethyl)aniline (Table 3, entry 12).
Yield: 10% (39 mg). Rf (5% EtOAc/pet. ether) 0.58. IR (liquid film)
3020, 2927, 2855, 1614, 1495, 1456, 1323, 1167, 1128, 1072, 967. 1H
4.4.12. Cinnamyl acetate: (Table 4, entry 7). Yield: 95% (167 mg). Rf
(5% EtOAc/pet. ether) 0.38. IR (liquid film) 3026, 2933, 1736, 1597,
1236, 966, 752. 1H NMR (300 MHz, CDCl3, 25 ꢀC):
d
¼7.2e7.4 (m, 5H,
NMR (300 MHz, CDCl3, 25 ꢀC):
d
¼7.21e7.55 (m, 11H, Ar), 7.00 (s, 1H,
Ph), 6.65 (d, J¼15.76 Hz, 1H, CH]CHePh), 6.28 (td, J¼15.76,
6.23 Hz, 1H, CH2eCH]CH), 4.72 (dd, J¼6.23, 1.1 Hz, 2H,
OeCH2eCH), 2.1 (s, CH3eCO2, 3H) ppm. 13C NMR (75 MHz, CDCl3,
Ar), 6.92e6.98 (m, 2H, Ar), 6.54 (d, J¼16.12 Hz, 2H, CH]CHePh),
6.24 (td, J¼16.12, 5.5 Hz, 2H, CH2eCH]CH), 4.17 (d, J¼4.40, 4H,
13
HNeCH2eCH) ppm. C NMR (75 MHz, CDCl3, 25 ꢀC):
d
¼148.02
25 ꢀC):
d
¼170 (CH3eCO2eCH2), 136.26 (Cq, Ar), 134.25 (CH]
(NeCq, Ar), 136.73 (2Cq, Ar), 131.81 (2CH2eCH]CH), 129.74
(CqeCF3), 128.67 (4CH, Ar), 127.70 (2CH, Ar), 126.45 (4CH, Ar),
124.93 (CH, Ar), 115.53 (CH, Ar), 113.07 (CH, Ar), 108.80 (CH, Ar),
52.31 (HNeCH2eCH) ppm. MSeMS (ESIþ): m/z calcd for (Mþ1):
394.17; found (Mþ1): 394.33. HRMS (ESIþ) calcd for C25H22NF3
(MþHþ): 394.1783, found 394.1777.
CHePh), 128.65 (2CH, Ar), 128.11 (CH, Ar), 126.66 (2CH, Ar), 123.23
(CH2eCH]CH), 65.11 (OeCH2), 21 (CH3) ppm. GCeMS (EI, 70 eV):
m/z (%)¼176 (28) [Mþ], 134 (40), 133 (39), 117 (29), 115 (86), 92 (35),
77 (20), 43 (100).
4.4.13. Cinnamyl benzoate (Table 4, entry 8). Yield: 95% (226 mg). Rf
(5% EtOAc/pet. ether) 0.5. IR (liquid film) 3020, 2930, 1717, 1602,
1
4.4.8. N-Cinnamyl-naphthylamine (Table 3, entry 16). Yield: 96%
(248 mg). Rf (5% EtOAc/pet. ether) 0.45. IR (liquid film) 3425, 3028,
2860, 1612, 1581, 1524, 966, 756. 1H NMR (300 MHz, CDCl3, 25 ꢀC):
1271, 1216, 967, 759. H NMR (300 MHz, CDCl3, 25 ꢀC):
d
¼8.1 (d,
J¼8.43 Hz, 2H, Ar), 7.2e5.9 (m, 8H, Ar), 6.75 (d, J¼15.76, 1H, CH]
CHePh), 6.4 (td, J¼15.76, 6.23 Hz, 1H, CH2eCH]CH), 5.0 (dd,
J¼6.23, 1.1 Hz, 2H, OeCH2eCH) ppm. 13C NMR (75 MHz, CDCl3,
d
¼7.77e7.84 (m, 2H, Ar), 7.2e7.4 (m, 9H, Ar), 6.7 (m, 1H, Ar), 6.66
(m, 1H, CH]CHePh), 6.43 (td, J¼15.76, 5.87 Hz, 1H, CH2eCH]CH),
25 ꢀC):
d
¼166.37 (CO2), 136.25 (CqeCH, Ar), 134.27 (CqeCO2, Ar),
4.5 (br s, 1H), 4.08 (d, J¼5.5 Hz, 2H, HNeCH2eCH) ppm. 13C NMR
133 (CH, Ar), 129.67 (2CH, Ar), 128.63 (2CH, Ar), 128.39 (2CH, Ar),
128.1 (CH]CHePh, Ar), 126.67 (2CH, Ar), 123.29 (CH2eCH]CH),
65.23 (OeCH2eCH) ppm. GCeMS (EI, 70 eV): m/z (%)¼238 (4) [Mþ],
133 (11), 117 (12), 115 (28), 105 (100), 77 (28), 45 (27).
(75 MHz, CDCl3, 25 ꢀC):
d¼143.25 (NeCq, Ar), 136.93 (Cq, Ar),
134.44 (Cq, Ar), 132.06 (CH]CHePh), 128.81(CH, Ar), 128.72 (2CH,
Ar), 127.72 (CH, Ar), 126.75 (2CH, Ar), 126.49 (2CH, Ar), 125.85 (CH,
Ar), 124.87 (CH, Ar), 123.63 (Cq, Ar), 120.02 (CH, Ar), 117.79 (CH, Ar),
104.98 (CH, Ar), 46.51 (HNeCH2eCH) ppm. GCeMS (EI, 70 eV): m/z
(%)¼339 (21) [Mþ], 234 (12), 227 (74), 223 (2), 117 (46), 115 (19), 91
(28), 44 (100). HRMS (ESIþ) calcd for C19H17N (MHþ) 260.1439,
found 260.1434.
Acknowledgements
The authors are greatly thankful to Council of Scientific and
Industrial Research (CSIR), India for providing fellowship. Also, the
authors express their gratitude to Dr. Koteppa Pari and Dr. Narendra
Raut at Piramal Life Sciences Limited, Mumbai, India for providing
HRMS analysis of products.
4.4.9. N-Cinnamyl-N-tosyl-aniline (Table 3, entry 18). Yield: 95%
(334 mg). Rf (10% EtOAc/pet. ether) 0.43. IR (liquid film) 3055, 2923,

Y.S. Wagh et al. / Tetrahedron 67 (2011) 2414e2421
2421
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