Highly efficient and practical phosphoramidite-copper catalysts for amination of aryl iodides and heteroaryl bromides with alkylamines and N(H)-heterocycles

Article abstract of DOI:10.1016/j.tet.2006.02.062

A highly efficient copper-catalyzed system using phosphoramidite as ligands was applied to N-arylation of alkylamines and N(H)-heterocycles with aryl iodides and heteroaryl bromides. The reactions were carried out in relative mild conditions and good to excellent yields were obtained.

Full text of DOI:10.1016/j.tet.2006.02.062

Tetrahedron 62 (2006) 4435–4443
Highly efficient and practical phosphoramidite–copper catalysts
for amination of aryl iodides and heteroaryl bromides
with alkylamines and N(H)-heterocycles
*
Zhanjin Zhang, Jincheng Mao, Di Zhu, Fan Wu, Huilin Chen and Boshun Wan
Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
Received 14 December 2005; revised 20 February 2006; accepted 20 February 2006
Available online 13 March 2006
Abstract—A highly efficient copper-catalyzed system using phosphoramidite as ligands was applied to N-arylation of alkylamines and
N(H)-heterocycles with aryl iodides and heteroaryl bromides. The reactions were carried out in relative mild conditions and good to excellent
yields were obtained.
q 2006 Elsevier Ltd. All rights reserved.
1. Introduction
communication (Scheme 1).35 In this paper, we further
explored the scope of substrates and applied this catalytic
system to copper-catalyzed N-arylation of alkylamines and
N(H)-heterocycles with aryl iodides and heteroaryl bro-
mides and found the ligand was highly effective for the
coupling reactions for a broader range of substrates.
N-Arylamines, N-arylpyrazoles, N-arylimidazoles, N-aryl-
pyridine and N-arylpyrimidine have attracted a great deal of
interest recently due to their importance in fields such as
natural products, photograph and materials.1–3 Palladium-
catalyzed C–N bond formation reactions have been
extensively explored in the past several years.4–7 However,
the copper-promoted N-arylation in mild conditions has
become a focus of research for large and industrial-scale
production from the practical point of view.8–11 Recently,
many ligands, such as 1,10-phenanthroline,12–16 trans-1,2-
cyclohexanediamine,17–21 ethylene glycol,22,23 amino
acid,1b,24,25 and other nitrogen, oxygen-containing
ligands26–29 have been developed and applied in copper-
catalyzed aminations under mild conditions. However, only
several papers have been contributed to N-arylation of
alkylamines and just a few ligands were found to be
effective in this transformation.30–32 Furthermore, two
major factors that hamper the application are the cost and
the availability of the catalysts, in particular of the ligands
that are often prepared in a tedious multi-step synthesis.
Therefore, to find more cost-effective and highly efficient
ligands is still desirable. Our group has embarked on a
program aimed at the ligands that are low-cost and easily
prepared in short pathway from readily available starting
materials.33,34 Very recently, the application of phosphor-
amidite to amination of aryl iodide has been reported in our
(i) PCl3
(ii) phenol
Ar1
Ar2
O
P NR1R2
R1R2NH
(R1R2N)3P
ether, 0 o
C
benzene
O
2-6
NH4Cl, 80 o
C
1
a R1 = R2 = CH3
b R1 = R2 = C2H5
c R1 = R2 = Pri
d R1 = R2 = CH2Ph
e R1-R2 = (CH2)4
Ar1-Ar2:
2
5
3
4
Ar1 = Ar2:
f R1-R2 = (CH2)2O(CH2)2
6
Scheme 1. Phosphoramidite ligands.
2. Results and discussion
Initially, the CuBr/2d/DMF/Cs2CO3 was screened as the
best catalytic system for the coupling of aliphatic primary
and secondary amines with aryl iodides. The results were
summarized in Table 1. It was found that phosphramidite
2d was a powerful promoter for coupling reaction in DMF
at 90 8C. When primary alkylamines were employed as
substrates, excellent yields were obtained (Table 1, entries
Keywords: Amination; Phosphoramidite; Heteroaryl bromide; Copper;
Catalysis.
Corresponding author. Tel./fax: C86 411 84379260;
e-mail: bswan@dicp.ac.cn
*
0040–4020/$ - see front matter q 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2006.02.062

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Z. Zhang et al. / Tetrahedron 62 (2006) 4435–4443
Table 1. Coupling of aryl iodides with primary and secondary aminesa
2d (5 mol%)
CuBr (2.5 mol%)
+
ArI
NHR
NH2R
Cs2CO3, DMF
Entry
ArI
NH2R
Product
Yield (%)b
N
H
I
I
NH2
NH2
1
2
96
96
N
H
NH
NH
I
I
3
4
96
98
NH2
NH2
NH2
N
H
I
I
5
6
97
98
N
H
NH2
NH2
I
7
8
9
98
99
98
NH
NO2
CN
NH2
NH2
N
H
I
O2N
NC
N
H
I
N
N
I
I
I
I
NH
NH
10
11
12
13
90
87
86
92
N
NH
NH
N
N
N
N
N
O
N
N
I
I
14
15
16
83
90
87
N
NH
O
O
NH
N
N
O
O
I
O
NH
O2N
NO2
NH
17
99
I
N
MeO
MeO
I
I
NH
NH
MeO
MeO
N
18
19
78
80
O
N
O
a Reaction conditions: CuBr (0.025 mmol), 2d (0.5 mmol), ArI (1.0 mmol), amine (1.5 mmol), and Cs2CO3 (3 mmol) in DMF (1 mL), 90 8C, 24 h.
b Isolated yields (average of two runs).
1–9). We then extended the scope of the substrates to
secondary amines. Good yields were observed in coupling
reaction (entries 10–19), but they were lower than that of
primary alkylamines. A wide variety of functional groups
such as cyano, nitro, methoxy could be tolerated on the
aryl iodide component under the reaction conditions.
Significant electronic effects were observed for substituted
aryl iodides. Excellent yields for the aryl iodides contain-
ing electron-withdrawing groups were achieved (entries
14–18).
amounts of CuBr and the ligand were doubled. The
N-arylation of imidazole could be smoothly carried out
using various aryl iodides (Table 2, entries 1–6). Benzimi-
dazole could be successfully coupled with good yields
(entries 7–12). The arylation of pyrazole could also be
carried out smoothly under mild reaction conditions (entry
13). Noticeably, electronic and steric factors played
important roles in the coupling reactions, high yields were
obtained for substrates possessing electron-withdrawing
groups (entries 5, 6, 11 and 12). A sterically hindered aryl
iodide gave lower yields (entries 3 and 9). Aryl iodides
containing a nitro, methoxy group, free NH2 were efficiently
transformed to products.
As can be seen from Table 2, several N-heterocycles could
be converted to the desired products effectively when the

Z. Zhang et al. / Tetrahedron 62 (2006) 4435–4443
Table 2. Coupling of aryl iodides with various N-heterocyclesa
4437
5 mol % CuBr
10 mol %2d
N-Heterocycle
+
I
N(H)-Heterocycle
R1
R1
2 equiv Cs2CO3
DMF, 90 oC, 24h
Entry
1
ArI
N(H)-heterocycle
Product
Yield (%)b
N
MeO
H2N
I
I
MeO
H2N
N
N
N
N
78
69
65
75
87
85
N
H
N
2
3
4
5
6
N
H
N
N
N
I
I
N
N
H
N
N
N
H
O2N
F3C
N
O2N
N
I
N
H
N
N
F3C
N
H
N
I
N
N
I
7
82
80
67
76
90
N
H
N
N
N
MeO
I
8
N
H
MeO
N
N
N
I
I
9
N
H
N
N
N
N
N
10
11
N
H
O2N
F3C
N
O2N
F3C
N
H
I
N
N
N
12
13
86
76
N
H
I
N
N
MeO
I
N
MeO
N
N
H
N
a Reaction conditions: 1.0 mmol ArI, 1.5 mmol amine, 0.05 mmol CuBr, 0.1 mmol 2d, 2 mmol Cs2CO3, in DMF (1 mL), at 90 8C for 24 h.
b Isolated yields (average of two runs).
Although chloro- and bromopyridine have been used as
effective coupling partners in Pd-catalyzed amination
reaction,7f,36 to the best of our knowledge, except one
paper,1b it was rarely reported that bromopyridines were
employed as coupling substrates in Cu-catalyzed amination.
When reaction time was prolonged to 36 h under above
reaction conditions, 2-bromopyridine and 3-bromopyridine
could be efficiently coupled with aliphatic primary,
secondary cyclic amines and N(H)-heterocycles (Table 3).
As seen in Table 3, in general, aliphatic primary amines
were excellent substrates for the coupling with bromopyr-
idine (Table 3, entries 1–6). Good results were observed for
coupling of aliphatic secondary cyclic amines and N(H)-
heterocycles (entries 7–12).
Although 5-bromopyrimidine has been utilized as effective
coupling substrates in Pd-catalyzed amination reactions, it
was less used in Cu-catalyzed amination.7d,28 Fortunately,
when phosphoramidite was used as the ligand in Cu-
catalyzed N-arylpyrimidine, a number of amines could be
coupled with 5-bromopyrimidine in good to excellent yields
in 36 h at 90 8C (Table 4). 5-bromopyrimidine could be
successfully reacted with aliphatic primary, secondary
cyclic amines and N(H)-heterocycles. Aliphatic primary
amines were excellent substrates for the coupling with
5-bromopyrimidine (Table 4, entries 1–8). Furthermore,
good results were also obtained for coupling of aliphatic
secondary cyclic amines and N(H)-heterocycles (entries
9–14).

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Z. Zhang et al. / Tetrahedron 62 (2006) 4435–4443
Table 3. Coupling of bromopyridines with various aminesa
5 mol % CuBr
10 mol % 2d
N
+
N
R1R2NH
NR1R2
2 equiv Cs2CO3
DMF, 90 oC, 36 h
Br
Entry
1
Bromopyridine
R1R2NH
Product
Yield (%)b
95
Br
N
N
H
H2N
N
N
Br
N
2
97
NH
H2N
Br
N
N
H
H2N
3
4
92
94
N
Br
N
H
H2N
N
N
N
Br
5
96
NH
H2N
H2N
HN
N
Br
N
H
6
7
8
9
90
85
82
76
N
N
N
N
Br
N
N
N
N
N
O
Br
N
HN
O
N
N
Br
N
N
N
HN
N
N
N
Br
N
10
N
78
N
H
N
N
Br
N
HN
11
12
74
77
N
N
N
N
N
Br
N
N
H
N
a Reaction conditions: 1.0 mmol bromopyridine, 1.5 mmol amine, 0.05 mmol CuBr, 0.1 mmol 2d, 2 mmol Cs2CO3, in DMF (1 mL) at 90 8C for 36 h.
b Isolated yield.
3. Conclusion
CDCl3 was used as the solvent for all NMR spectra. High
resolution mass spectra (HRMS) were recorded on a
Mariner 5303 (Applied Biosystems, USA). All products
were characterized by H NMR and HRMS and compared
with the previously reported data.19,20,24,28,30,37,38
In conclusion, we developed a mild and practical copper-
catalyzed N-arylation of alkylamines and N(H)-heterocycles
with aryl iodides and heteroaryl bromides using phosphor-
amidite ligand. It demonstrated that all reactions could be
smoothly carried out at relatively low temperature in good to
excellent yields. The ligands were stable, cost-effective, and
easily synthesized from inexpensive, commercially available
starting materials using a simple, efficient method.
1
All reactions were carried out under an argon atmosphere.
Column chromatography purifications were performed
using silica gel. All solvents were dried and degassed by
standard methods and all starting materials were commer-
cially available. Petroleum ether refers to the boiling range
of 60–90 8C. When solvent gradient was used, the increase
of polarity was made gradually from petroleum ether to
mixtures of petroleum ether/ethyl acetate until the isolation
of the products.
4. Experimental
4.1. Materials and methods
Melting points were measured on a YAZAWA micro
melting point apparatus (uncorrected). 1H, 31P and 13C
NMR spectra were measured on a Bruker DRX-400 NMR
spectrometer (400 MHz) with TMS as an internal reference.
4.2. Typical experimental procedure of N-arylation
CuBr (3.6 mg, 0.025 mmol), Cs2CO3 (977.5 mg, 3 mmol)
and ligand 2d (25.6 mg, 0.05 mmol) were added to

Z. Zhang et al. / Tetrahedron 62 (2006) 4435–4443
Table 4. Coupling of 5-bromopyrimidine with various aminesa
4439
5 mol % CuBr
N
N
N
N
10 mol %2d
R1R2NH
NR1R2
Br
+
2 equiv Cs2CO3
DMF, 90 oC, 36 h
Entry
1
R1R2NH
Product
Yield (%)b
90
N
N
H2N
NH
N
N
H
H2N
2
3
97
94
N
N
NH
H2N
H2N
N
N
4
5
89
96
NH
N
N
N
NH
H2N
N
N
N
H
H2N
6
92
94
95
83
85
80
86
N
H
N
H2N
7
N
N
N
H
H2N
8
N
N
N
N
HN
9
N
N
HN
10
11
12
N
N
HN
N
N
N
N
N
N
N
O
O
HN
O
O
N
N
HN
N
13
14
78
73
N
N
N
N
N
N
H
a Reaction conditions: 1.0 mmol bromopyrimidine, 1.5 mmol amine, 0.05 mmol CuBr, 0.1 mmol 2d, 2 mmol Cs2CO3, in DMF (1 mL) at 90 8C for 36 h.
b Isolated yield.
a Schlenk tube. The Schlenk tube was then evacuated and
backfilled with argon (5 cycles). DMF (1 mL), amine
(1.5 mmol) (if liquid), and aryl iodide (1 mmol) were added
by syringe at room temperature. The Schlenk tube was then
charged with argon and sealed. The reaction mixture was
heated at 90 8C under stirring for 24 h. After cooling to
ambient temperature, the resulting mixture was added with
4 mL of ethyl acetate and 10 mL of water. The organic layer
was separated and the aqueous layer was further extracted
with ethyl acetate (4!10 mL). The combined organic phase
was washed with brine and dried over Na2SO4. Solvent was
removed in vacuo and the residue was further purified by
flash column chromatography on silica gel to afford the
desired product.
4.3. Cross-coupling data of aryl iodides with primary
and secondary amines
4.3.1. N-(iso-Propyl)aniline (Table 1, entry 1). Colorless
1
liquid (0.1298 g, 96%). H NMR: d 1.17 (d, JZ8.0 Hz,
6H), 3.35 (br, 1H), 3.56–3.62 (m, 1H), 6.54–6.56 (m, 2H),

4440
Z. Zhang et al. / Tetrahedron 62 (2006) 4435–4443
6.63–6.67 (m, 1H), 7.12–7.16 (m, 2H). HRMS (APCI) calcd
for C9H14N (MCHC): 136.1121, found: 136.1120.
3.23 (t, JZ8.0 Hz, 4H), 6.53 (d, JZ8.0 Hz, 2H), 6.62–6.65
(m, 1H), 7.18–7.22 (m, 2H). HRMS (APCI) calcd for
C10H14N (MCHC): 148.1121, found: 148.1131.
4.3.2. N-(Butyl)aniline (Table 1, entry 2). Colorless liquid
(0.1433 g, 96%). 1H NMR: d 0.94 (t, JZ8.0 Hz, 3H), 1.36–
1.45 (m, 2H), 1.53–1.61 (m, 2H), 3.07 (t, JZ8.0 Hz, 2H),
3.54 (br, 1H), 6.56–6.58 (m, 1H), 6.65–6.69 (m, 2H), 7.13–
7.33 (m, 2H). HRMS (APCI) calcd for C10H16N (MCHC):
150.1277, found: 150.1268.
4.3.11. N-(Phenyl)piperidine (Table 1, entry 11). Color-
less liquid (0.1403 g, 87%). 1H NMR: d 1.52–1.58 (m, 2H),
1.66–1.72 (m, 4H), 3.13 (t, JZ8.0 Hz, 4H), 6.79–6.82 (m,
1H), 6.93 (d, JZ8.0 Hz, 2H), 7.18–7.25 (m, 2H). HRMS
(APCI) calcd for C11H16N (MCHC): 162.1277, found:
162.1271.
4.3.3. N-(iso-Butyl)aniline (Table 1, entry 3). Colorless
liquid (0.1433 g, 96%). 1H NMR: d 0.95 (d, JZ4.0 Hz, 6H),
1.82–1.88 (m, 1H), 2.89 (d, JZ8.0 Hz, 2H), 3.61 (br, 1H),
6.56 (d, JZ8.0 Hz, 2H), 6.64–6.68 (m, 1H), 7.13–7.16 (m,
2H). HRMS (APCI) calcd for C10H16N (MCHC):
150.1277, found: 150.1288.
4.3.12. N-Phenyl-N-(methyl)piperazine (Table 1, entry
12). Colorless liquid (0.1516 g, 86%). H NMR: d 2.33 (s,
3H), 2.55 (t, JZ4.0 Hz, 4H), 3.19 (t, JZ4.0 Hz, 4H),
6.83–6.91 (m, 3H), 7.24–7.27 (m, 2H). HRMS (APCI) calcd
for C11H17N2 (MCHC): 177.1386, found: 177.1376.
1
4.3.4. N-(sec-Butyl)aniline (Table 1, entry 4). Colorless
liquid (0.1462 g, 98%). 1H NMR: d 0.91–0.97 (m, 3H), 1.14
(d, JZ4.0 Hz, 3H), 1.41–1.48 (m, 1H), 1.54–1.61 (m, 1H),
3.35–3.40 (m, 2H), 6.56 (d, JZ8.0 Hz, 2H), 6.63–6.66 (m,
1H), 7.12–7.16 (m, 2H). HRMS (APCI) calcd for C10H16N
(MCHC): 150.1277, found: 150.1265.
4.3.13. N-Phenyl-N-(ethyl)piperazine (Table 1, entry 13).
White solid (0.1750 g, 92%); mp 38–39 8C. H NMR: d
1.11–1.15 (m, 3H), 2.45–2.50 (m, 2H), 2.61 (t, JZ8.0 Hz,
4H), 3.22 (t, JZ8.0 Hz, 4H), 6.83–6.87 (m, 1H), 6.93
(d, JZ12.0 Hz, 2H), 7.24–7.34 (m, 2H). HRMS (APCI)
calcd for C12H19N2 (MCHC): 191.1543, found: 191.1528.
1
4.3.5. N-Cyclopentylaniline (Table 1, entry 5). Colorless
liquid (0.1564 g, 97%). 1H NMR: d 1.18–1.26 (m, 8H), 3.41
(br, 1H), 3.58–3.62 (m, 1H), 6.57 (d, JZ8.0 Hz, 2H), 6.64–
6.68 (m, 1H), 7.13–7.17 (m, 2H). HRMS (APCI) calcd for
C11H16N (MCHC): 162.1277, found: 162.1265.
4.3.14. N-(Phenyl)piperazincarboxylethylether (Table 1,
entry 14). White solid (0.1812 g, 83%); mp 57–58 8C. H
NMR: d 1.28 (t, JZ8.0 Hz, 3H), 3.13 (t, JZ4.0 Hz, 4H),
3.62 (t, JZ8.0 Hz, 4H), 4.14–4.19 (m, 2H), 6.87–6.94 (m,
3H), 7.25–7.35 (m, 2H). HRMS (APCI) calcd for
C13H19N2O (MCHC): 235.1441, found: 235.1436.
1
4.3.6. N-Cyclohexylaniline (Table 1, entry 6). Colorless
liquid (0.1717 g, 98%). 1H NMR: d 1.09–1.21 (m, 3H), 1.32
(t, JZ16.0 Hz, 2H), 1.62 (t, JZ8.0 Hz, 1H), 1.71–1.76 (m,
2H), 2.02 (d, JZ12.0 Hz, 2H), 3.18–3.24 (m, 1H), 3.44 (br,
1H), 6.55 (d, JZ8.0 Hz, 2H), 6.63 (t, JZ4.0 Hz, 1H), 7.13
(t, JZ8.0 Hz, 2H). HRMS (APCI) calcd for C12H18N (MC
HC): 176.1434, found: 176.1430.
4.3.15. N-(Phenyl)morpholine (Table 1, entry 15). White
solid (0.1469 g, 90%); mp 53–54 8C. 1H NMR: d 3.14 (t, JZ
8.0 Hz, 4H), 3.85 (t, JZ8.0 Hz, 4H), 6.86–6.92 (m, 3H),
7.23–7.30 (m, 2H). HRMS (APCI) calcd for C10H14NO
(MCHC): 164.1070, found: 164.1058.
4.3.16. N-Phenyl-3,5-dimethylmorpholine (Table 1,
entry 16). Colorless liquid (0.1664 g, 87%). H NMR: d
1.23–1.30 (m, 6H), 2.35–2.41 (m, 2H), 3.42 (d, JZ12.0 Hz,
2H), 3.76–4.12 (m, 2H), 6.83–6.90 (m, 3H), 7.23–7.27 (m,
2H). HRMS (APCI) calcd for C12H18NO (MCHC):
192.1383, found: 192.1387.
1
4.3.7. N-(Phenyl)benzylamine (Table 1, entry 7). White
solid (0.1796 g, 98%); mp 33–34 8C. H NMR: d 3.99 (br,
1H), 4.29 (s, 2H), 6.61 (d, JZ8.0 Hz, 2H), 6.68–6.72 (m,
1H), 7.14–7.18 (m, 2H), 7.24–7.27 (m, 1H), 7.30–7.36 (m,
4H). HRMS (APCI) calcd for C13H14N (MCHC):
184.1121, found: 184.1129.
1
4.3.17. N-(3-Nitrophenyl)pyrrolidine (Table 1, entry 17).
Yellow solid (0.1903 g, 99%); mp 33–34 8C. H NMR: d
2.04–2.09 (m, 4H), 3.33 (t, JZ8.0 Hz, 4H), 6.79 (t,
JZ4.0 Hz, 1H), 7.26–7.32 (m, 2H), 7.44–7.46 (m, 1H).
HRMS (APCI) calcd for C10H13N2O2 (MCHC): 193.0972,
found: 193.0967.
1
4.3.8. N-(Butyl)-3-nitroaniline (Table 1, entry 8). Yellow
liquid (0.1923 g, 99%). 1H NMR: d 0.96 (t, JZ8.0 Hz, 3H),
1.39–1.48 (m, 2H), 1.58–1.66 (m, 2H), 3.14 (t, JZ8.0 Hz,
2H), 4.05 (br, 1H), 6.84–6.86 (m, 1H), 7.24 (t, JZ8.0 Hz,
1H), 7.36 (s, 1H), 7.47 (d, JZ8.0 Hz, 1H). HRMS (APCI)
calcd for C10H15N2O2 (MCHC): 195.1128, found:
195.1113.
4.3.18. N-(4-Methoxyphenyl)piperazine (Table 1, entry
18). White solid (0.1492 g, 78%); mp 64–65 8C. 1H NMR: d
1.51–1.57 (m, 2H), 1.69–1.75 (m, 4H), 3.02 (t, JZ4.0 Hz,
4H), 3.75 (d, JZ8.0 Hz, 3H), 6.83 (t, JZ8.0 Hz, 2H), 6.92
(d, JZ8.0 Hz, 2H). HRMS (APCI) calcd for C12H18NO
(MCHC): 192.1383, found: 192.1371.
4.3.9. N-(Butyl)-3-nitrylaniline (Table 1, entry 9). Green-
1
ish liquid (0.1708 g, 98%). H NMR: d 0.96 (t, JZ8.0 Hz,
3H), 1.38–1.48 (m, 2H), 1.57–1.64 (m, 2H), 3.09 (t, JZ
8.0 Hz, 2H), 3.93 (br, 1H), 6.76 (t, JZ8.0 Hz, 2H), 6.92 (d,
JZ8.0 Hz, 1H), 7.18–7.27 (m, 1H), 7.47 (d, JZ8.0 Hz, 1H).
HRMS (APCI) calcd for C11H15N2 (MCHC): 175.1230,
found: 175.1218.
4.3.19. N-(4-Methoxyphenyl)morpholine (Table 1, entry
19). White solid (0.1546 g, 80%); mp 66–67 8C. 1H NMR: d
3.06 (d, JZ4.0 Hz, 4H), 3.77 (s, 3H), 3.86 (s, 4H),
6.84–6.91 (m, 4H). HRMS (APCI) calcd for C11H16NO2
(MCHC): 194.1176, found: 194.1184.
4.3.10. N-(Phenyl)pyrrolidine (Table 1, entry 10). Color-
less liquid (0.1325 g, 90%). 1H NMR: d 1.93–1.97 (m, 4H),

Z. Zhang et al. / Tetrahedron 62 (2006) 4435–4443
4441
4.4. Cross-coupling data of aryl iodides with various
N-heterocycles
4.4.11. N-(3-Nitrophenyl)benzimidazole (Table 2, entry
12). Yellowish solid (0.2153 g, 90%); mp 145–146 8C. H
1
NMR: d 7.38–7.40 (m, 2H), 7.51–7.58 (m, 1H), 7.78–7.83
(m, 1H), 7.90 (d, JZ8.0 Hz, 2H), 8.19 (s, 1H), 8.32 (d, JZ
12.0 Hz, 1H), 8.43 (s, 1H). HRMS (APCI) calcd for
C13H10N3O2 (MCHC): 240.0767, found: 240.0754.
4.4.1. N-(4-Methoxyphenyl)imidazole (Table 2, entry 1).
White solid (0.1359 g, 78%); mp 121–122 8C. H NMR: d
3.82 (s, 3H), 6.94–6.98 (m, 2H), 7.17–7.29 (m, 4H), 7.72–
7.81 (s, 1H). HRMS (APCI) calcd for C10H11N2O (MC
HC): 175.0866, found: 175.0853.
1
4.4.12. N-(3-Trifluoromethylphenyl)benzimidazole
(Table 2, entry 13). Colorless liquid (0.2255 g, 86%). H
1
NMR: d 7.32–7.36 (m, 2H), 7.48–7.51 (m, 1H), 7.69–7.72
(m, 3H), 7.79 (1H), 7.86–7.89 (m, 1H), 8.13 (s, 1H). HRMS
(APCI) calcd for C14H10F3N2 (MCHC): 263.0791, found:
263.0805.
4.4.2. N-(4-Aminophenyl)imidazole (Table 2, entry 2).
White solid (0.1098 g, 69%); mp 138–139 8C. H NMR: d
3.53 (br, 2H), 6.74 (d, JZ8.0 Hz, 2H), 7.15 (d, JZ4.0 Hz,
4H), 7.81 (s, 1H). HRMS (APCI) calcd for C9H10N3 (MC
HC): 160.0869, found: 160.0854.
1
4.4.13. N-(4-Methoxyphenyl)pyrazole (Table 2, entry 7).
White solid (0.1428 g, 82%); mp 32–33 8C. 1H NMR: d 3.84
(s, 3H), 6.43–6.44 (m, 1H), 6.95–6.98 (m, 2H), 7.58–7.61
(m, 2H), 7.69 (s, 1H), 7.81 (d, JZ4.0 Hz, 1H). HRMS
(APCI) calcd for C10H11N2O (MCHC): 175.0866, found:
175.0872.
4.4.3. N-(2-Methylphenyl)imidazole (Table 2, entry 3).
Colorless liquid (0.1028 g, 65%). H NMR: d 2.18 (s, 3H),
7.14–7.27 (m, 4H), 7.28–7.37 (m, 2H), 8.46 (s, 1H). HRMS
(APCI) calcd for C10H11N2 (MCHC): 159.0917, found:
159.0912.
1
4.5. Cross-coupling data of bromopyridine with various
amines
4.4.4. N-(3-Methylphenyl)imidazole (Table 2, entry 4).
Colorless liquid (0.1187 g, 75%). H NMR: d 2.41 (s, 3H),
1
7.16–7.49 (m, 6H), 7.86 (s, 1H). HRMS (APCI) calcd for
C10H11N2 (MCHC): 159.0917, found: 159.0902.
4.5.1. 2-(Butylamimo)pyridine (Table 3, entry 1). White
solid (0.1427 g, 95%); mp 32–33 8C. 1H NMR: d 0.93 (t, JZ
8.0 Hz, 3H), 1.36–1.45 (m, 2H), 1.54–1.61 (m, 2H), 3.19–
3.24 (m, 2H), 4.75 (br, 2H), 6.34 (d, JZ8.0 Hz, 2H), 6.50–
6.53 (m, 1H), 7.35–7.40 (m, 1H), 8.03 (d, JZ4.0 Hz, 1H).
HRMS (APCI) calcd for C9H15N2 (MCHC): 151.1230,
found: 151.1221.
4.4.5. N-(3-Nitrophenyl)imidazole (Table 2, entry 5).
Yellowish solid (0.1646 g, 87%); mp 93–94 8C. 1H NMR: d
7.27–7.38 (m, 2H), 7.69–7.78 (m, 2H), 7.95 (s, 1H), 8.23–
8.28 (m, 2H). HRMS (APCI) calcd for C9H8N3O2 (MC
HC): 190.0611, found: 190.0600.
4.5.2. 2-(Benzylamimo)pyridine (Table 3, entry 2). White
solid (0.1787 g, 97%); mp 79–80 8C. H NMR: d 4.47 (d,
JZ4.0 Hz, 2H), 5.06 (br, 1H), 6.34 (d, JZ4.0 Hz, 1H),
6.52–6.57 (m, 1H), 7.26–7.39 (m, 1H), 8.06 (d, JZ4.0 Hz,
1H). HRMS (APCI) calcd for C12H13N2 (MCHC):
192.1495, found: 192.1508.
1
4.4.6. N-(3-Trifluoromethylphenyl)imidazole (Table 2,
entry 6). Colorless liquid (0.1803 g, 85%). H NMR: d
7.25–7.73 (m, 6H), 8.01 (s, 1H). HRMS (APCI) calcd for
C10H8F3N2 (MCHC): 213.0634, found: 213.0623.
1
4.4.7. N-(Phenyl)benzimidazole (Table 2, entry 8). Color-
less liquid (0.1554 g, 80%). 1H NMR: d 7.24–7.30 (m, 2H),
7.34–7.38 (m, 3H), 7.44–7.48 (m, 3H), 7.86 (d, JZ8.0 Hz,
1H), 8.04 (s, 1H). HRMS (APCI) calcd for C13H11N2 (MC
HC): 195.0917, found: 195.0903.
4.5.3. 2-(Cyclohexylamimo)pyridine (Table 3, entry 3).
White solid (0.1622 g, 92%); mp 103–104 8C. H NMR: d
1
1.18–1.24 (m, 3H), 1.35–1.42 (m, 2H), 1.60–1.78 (m, 3H),
2.01–2.05 (m, 2H), 3.48–3.56 (m, 1H), 4.48 (br, 1H), 6.35
(d, JZ8.0 Hz, 1H), 6.49–6.54 (m, 1H), 7.91 (d, JZ8.0 Hz,
1H), 8.04 (d, JZ4.0 Hz, 1H). HRMS (APCI) calcd for
C11H17N2 (MCHC): 177.1386, found: 177.1381.
4.4.8. N-(4-Methoxyphenyl)benzimidazole (Table 2,
entry 9). White solid (0.1741 g, 80%); mp 94–95 8C. H
1
NMR: d 3.87 (s, 3H), 7.05–7.07 (m, 2H), 7.30–7.33 (m, 2H),
7.39–7.45 (m, 3H), 7.86–7.88 (m, 1H), 8.06 (s, 1H). HRMS
(APCI) calcd for C14H13N2O (MCHC): 225.1022, found:
225.1036.
4.5.4. 3-(Butylamimo)pyridine (Table 3, entry 4). White
solid (0.1412 g, 94%); mp 35–36 8C. H NMR: d 0.94 (t,
1
JZ4.0 Hz, 3H), 1.39–1.44 (m, 2H), 1.57–1.62 (m, 2H),
3.02–3.16 (m, 2H), 4.07 (br, 1H), 6.84–6.86 (m, 1H), 7.04–
7.07 (m, 1H), 7.90 (d, JZ4.0 Hz, 1H), 8.00 (d, JZ4.0 Hz,
1H). HRMS (APCI) calcd for C9H15N2 (MCHC):
151.1230, found: 151.1237.
4.4.9. N-(2-Methylphenyl)benzimidazole (Table 2, entry
10). Colorless liquid (0.1395 g, 67%). H NMR: d 2.09
1
(s, 3H), 7.16–7.45 (m, 6H), 7.90 (d, JZ4.0 Hz, 2H), 8.00
(s, 1H). HRMS (APCI) calcd for C14H13N2 (MCHC):
209.1073, found: 209.1087.
4.5.5. 3-(Benzylamimo)pyridine (Table 3, entry 5). White
solid (0.1768 g, 96%); mp 77–78 8C. H NMR: d 4.28–4.36
1
(m, 2H), 5.23 (br, 1H), 6.84–6.87 (m, 1H), 7.03–7.06 (m, 1H),
7.93 (d, JZ4.0 Hz, 1H), 8.04 (s, 1H). HRMS (APCI) calcd for
C12H13N2 (MCHC): 185.1073, found: 185.1056.
4.4.10. N-(3-Methylphenyl)benzimidazole (Table 2,
entry 11). Colorless liquid (0.1583 g, 76%). H NMR: d
1
2.42 (s, 3H), 7.21–7.51 (m, 6H), 7.85–7.87 (m, 2H), 8.07 (s,
1H). HRMS (APCI) calcd for C14H13N2 (MCHC):
209.1073, found: 209.1054.
4.5.6. 3-(Cyclohexylamimo)pyridine (Table 3, entry 6).
White solid (0.1587 g, 90%); mp 91–92 8C. 1H NMR:

4442
Z. Zhang et al. / Tetrahedron 62 (2006) 4435–4443
d 1.15–1.24 (m, 3H), 1.35 (t, JZ16.0 Hz, 1H), 1.62–1.74
(m, 1H), 1.74–1.79 (m, 2H), 2.02–2.06 (m, 2H), 3.17–3.27
(m, 1H), 3.64 (br, 1H), 6.83–6.86 (m, 1H), 7.03–7.06 (m,
1H), 7.89 (d, JZ4.0 Hz, 1H), 7.96 (d, JZ20.0 Hz, 1H).
HRMS (APCI) calcd for C11H17N2 (MCHC): 177.1386,
found: 177.1378.
4.6.3. 5-(iso-Butylamimo)pyrimidine (Table 4, entry 3).
Colorless liquid (0.1421 g, 94%). 1H NMR: d 0.99–1.01 (d,
JZ8.0 Hz, 6H), 1.77–1.84 (m, 1H), 3.03 (d, JZ8.0 Hz, 2H),
4.69 (br, 1H), 8.01 (s, 2H), 8.19 (s, 1H). HRMS (APCI)
calcd for C8H14N3 (MCHC): 152.1182, found: 152.1174.
4.6.4. 5-(sec-Butylamimo)pyrimidine (Table 4, entry 4).
Colorless liquid (0.1354 g, 89%). 1H NMR: d 0.95–0.99 (m,
3H), 1.21 (d, JZ8.0 Hz, 3H), 1.51–1.63 (m, 2H), 3.38–3.45
(m, 1H), 3.97 (br, 1H), 8.09 (s, 2H), 8.53 (s, 1H). HRMS
(APCI) calcd for C8H14N3 (MCHC): 152.1182, found:
152.1168.
4.5.7. N-(2-Pyridinyl)-N-(ethyl)piperazine (Table 3,
entry 7). Colorless liquid (0.1626 g, 85%). H NMR: d
1.13 (t, JZ8.0 Hz, 3H), 2.44–2.49 (m, 2H), 2.55 (t, JZ
4.0 Hz, 4H), 3.53–3.58 (m, 4H), 6.59–6.65 (m, 2H), 7.44–
7.53 (m, 1H), 8.18–8.19 (m, 1H). HRMS (APCI) calcd for
C11H18N3 (MCHC): 192.1495, found: 192.1508.
1
4.6.5. 5-(Benzylamimo)pyrimidine (Table 4, entry 5).
White solid (0.1778 g, 96%); mp 99–100 8C. H NMR: d
4.30–4.39 (m, 2H), 5.21 (br, 1H), 8.16 (s, 2H), 8.57 (s, 1H).
HRMS (APCI) calcd for C11H12N3 (MCHC): 186.1026,
found: 186.1031.
1
4.5.8. N-(2-Pyridinyl)morpholine (Table 3, entry 8).
Colorless liquid (0.1346 g, 82%). H NMR: d 3.47 (t, JZ
4.0 Hz, 4H), 3.79 (t, JZ6.0 Hz, 4H), 6.60–6.65 (m, 2H),
7.45–7.49 (m, 1H), 8.18–8.20 (m, 1H). HRMS (APCI) calcd
for C9H13N2O (MCHC): 165.1022, found: 165.1015.
1
4.6.6. 5-(Cylcopropylamino)pyrimidine (Table 4, entry 6).
White solid (0.1244 g, 92%); mp 86–87 8C. 1H NMR: d 0.54–
0.58 (m, 2H), 0.76–0.84 (m, 2H), 2.44–2.49 (m, 1H), 4.60 (br,
1H), 8.27 (s, 2H), 8.60 (s, 1H). HRMS (APCI) calcd for
C7H10N3 (MCHC): 136.0869, found: 136.0861.
4.5.9. N-(2-Pyridinyl)imidazole (Table 3, entry 9). Color-
less liquid (0.1104 g, 76%). 1H NMR: d 7.21–7.25 (m, 2H),
7.35 (t, JZ4.0 Hz, 1H), 7.68 (d, JZ16.0 Hz, 1H), 7.80–7.84
(m, 1H), 8.38 (s, 1H), 8.46–8.48 (m, 1H). HRMS (APCI)
calcd for C8H8N3 (MCHC): 146.0713, found: 146.0707.
4.6.7. 5-(Cylcopentylamino)pyrimidine (Table 4, entry 7).
Colorless liquid (0.1534 g, 94%). 1H NMR: d 1.48–1.52 (m,
2H), 1.63–1.76 (m, 4H), 2.02–2.08 (m, 2H), 3.75–3.81 (m,
1H), 4.31 (br, 1H), 8.12 (s, 2H), 8.54 (s, 1H). HRMS (APCI)
calcd for C9H14N3 (MCHC): 164.1182, found: 164.1171.
4.5.10. N-(2-Pyridinyl)benzoimidazole (Table 3, entry
10). Colorless liquid (0.1242 g, 78%). H NMR: d 7.23
(s, 1H), 7.33–7.36 (m, 2H), 7.48 (d, JZ8.0 Hz, 1H), 7.80
(d, JZ4.0 Hz, 1H), 7.85 (t, JZ6.0 Hz, 1H), 8.03 (t, JZ
4.0 Hz, 1H), 8.56 (s, 2H). HRMS (APCI) calcd for
C12H10N3 (MCHC): 196.0869, found: 196.0851.
1
4.6.8. 5-(Cyclohexylamimo)pyrimidine (Table 4, entry 8).
White solid (0.1683 g, 95%); mp 109–110 8C. H NMR: d
1
1.18–1.26 (m, 3H), 1.37 (t, JZ8.0 Hz, 2H), 1.62–1.73 (m,
1H), 1.76–1.81 (m, 2H), 2.03–2.07 (m, 2H), 3.25–3.30 (m,
1H), 3.71 (s, 1H), 8.09 (s, 2H), 8.54 (s, 1H). HRMS (APCI)
calcd for C10H16N3 (MCHC): 178.1139, found: 178.1328.
4.5.11. N-(3-Pyridinyl)imidazole (Table 3, entry 11).
Colorless liquid (0.1074 g, 74%). 1H NMR: d 7.30–7.36 (m,
2H), 7.44–7.47 (m, 1H), 7.74–7.76 (m, 1H), 7.94 (s, 1H),
8.62 (t, JZ4.0 Hz, 1H), 8.74 (s, 1H). HRMS (APCI) calcd
for C8H8N3 (MCHC): 146.0713, found: 146.0700.
4.6.9. 5-(Pyrimidinyl)pyrrolidine (Table 4, entry 9).
Colorless liquid (0.1238 g, 83%). H NMR: d 1.94–2.02
1
4.5.12. N-(3-Pyridinyl)benzoimidazole (Table 3, entry
12). White solid (0.1503 g, 77%); mp 89–91 8C. 1H NMR: d
7.36–7.38 (m, 2H), 7.50–7.56 (m, 2H), 7.86–7.90 (m, 2H),
8.16 (s, 1H), 8.73 (d, JZ4.0 Hz, 1H), 8.86 (s, 1H). HRMS
(APCI) calcd for C12H10N3 (MCHC): 196.0869, found:
196.0860.
(m, 4H), 3.20–3.24 (m, 4H), 8.00 (s, 2H), 8.53 (s, 1H).
HRMS (APCI) calcd for C8H12N3 (MCHC): 150.1026,
found: 150.1029.
4.6.10. 5-(Pyrimidinyl)piperidine (Table 4, entry 10).
Colorless liquid (0.1387 g, 85%). 1H NMR: d 1.55–1.62 (m,
2H), 1.63–1.72 (m, 4H), 3.20–3.27 (m, 4H), 8.35 (s, 1H),
8.61 (s, 1H). HRMS (APCI) calcd for C9H14N3 (MCHC):
164.1182, found: 164.1172.
4.6. Cross-coupling data of 5-bromopyrimidine
with various amines
4.6.1. 5-(iso-Propylamino)pyrimidine (Table 4, entry 1).
White solid (0.1235 g, 90%); mp 49–50 8C. 1H NMR: d 1.25
(d, JZ8.0 Hz, 6H), 3.64–3.65 (m, 1H), 3.85 (br, 1H), 8.10
(s, 2H), 8.55 (s, 1H). HRMS (APCI) calcd for C7H12N3
(MCHC): 138.1026, found: 138.1012.
4.6.11. N-(5-Pyrimidinyl)-N-(ethyl)piperazine (Table 4,
entry 11). Colorless liquid (0.1538 g, 80%). H NMR: d
1.13 (t, JZ8.0 Hz, 3H), 2.46–2.51 (m, 2H), 2.62 (t, JZ
4.0 Hz, 4H), 3.29 (t, JZ4.0 Hz, 4H), 8.37 (s, 2H), 8.68
(s, 1H). HRMS (APCI) calcd for C10H17N4 (MCHC):
193.1448, found: 193.1434.
1
4.6.2. 5-(Butylamimo)pyrimidine (Table 4, entry 2).
White solid (0.1467 g, 97%); mp 73–74 8C. H NMR: d
0.91–0.99 (m, 3H), 1.42–1.47 (m, 2H), 1.60–1.66 (m, 2H),
3.15 (t, JZ8.0 Hz, 2H), 4.05 (br, 1H), 8.06 (s, 2H), 8.55
(s, 1H). HRMS (APCI) calcd for C8H14N3 (MCHC):
152.1182, found: 152.1169.
1
4.6.12. N-(5-Pyrimidinyl)morpholine (Table 4, entry 12).
Colorless liquid (0.1421 g, 86%). H NMR: d 3.22 (t, JZ
4.0 Hz, 4H), 3.87 (t, JZ4.0 Hz, 4H), 8.36 (s, 2H), 8.64
(s, 1H). HRMS (APCI) calcd for C8H12N3O (MCHC):
166.0975, found: 166.0960.
1

Z. Zhang et al. / Tetrahedron 62 (2006) 4435–4443
4443
14. Wolter, M.; Klapars, A.; Buchwald, S. L. Org. Lett. 2001, 3,
3803–3805.
4.6.13.
N-(5-Pyrimidinyl)-2,6-dimethylmorpholine
1
(Table 4, entry 13). Colorless liquid (0.1508 g, 78%). H
NMR: d 1.29 (t, JZ8.0 Hz, 6H), 2.50 (t, JZ6.0 Hz, 4H),
3.79–3.83 (m, 2H), 8.36 (s, 2H), 8.69 (s, 1H). HRMS
(APCI) calcd for C10H16N3O (MCHC): 194.1288, found:
194.1279.
15. Gujadhur, R. K.; Bates, C. G.; Venkataraman, D. Org. Lett.
2001, 3, 4315–4317.
16. Evindar, G.; Batey, R. A. Org. Lett. 2003, 5, 133–136.
17. Klapars, A.; Antilla, J. C.; Huang, X.; Buchwald, S. L. J. Am.
Chem. Soc. 2001, 123, 7727–7729.
4.6.14. N-(5-Pyrimidinyl)benzoimidazole (Table 4, entry
14). White solid (0.1432 g, 73%); mp 143–144 8C. 1H
NMR: d 7.40–7.44 (m, 2H), 7.52 (d, JZ4.0 Hz, 4H), 7.93
(t, JZ8.0 Hz, 1H), 9.03 (s, 1H), 9.34 (s, 1H). HRMS (APCI)
calcd for C11H9N4 (MCHC): 197.0822, found: 197.0812.
18. Klapars, A.; Huang, X.; Buchwald, S. L. J. Am. Chem. Soc.
2002, 124, 7421–7428.
19. Antilla, J. C.; Klapars, A.; Buchwald, S. L. J. Am. Chem. Soc.
2002, 124, 11684–11688.
20. Antilla, J. C.; Baskin, J. M.; Barder, T. E.; Buchwald, S. L.
J. Org. Chem. 2004, 69, 5578–5587.
21. Mallesham, B.; Rajesh, B. M.; Reddy, P. R.; Srinivas, D. S.
Org. Lett. 2003, 5, 963–965.
Acknowledgements
22. Kwong, F. Y.; Klapars, A.; Buchwald, S. L. Org. Lett. 2002, 4,
581–584.
Financial support from the National Key Project for Basic
Research (2003CB114402) is gratefully acknowledged.
23. Enguehard, C.; Allouchi, H.; Gueiffier, A.; Buchwald, S. L.
J. Org. Chem. 2003, 68, 4367–4370.
24. Ma, D.; Cai, Q.; Zhang, H. Org. Lett. 2003, 5, 2453–2455.
25. Deng, W.; Wang, Y.-F.; Zou, Y.; Liu, L.; Guo, Q.-X.
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