Zinc-mediated radical reactions of per- (or poly)fluorophenyl aromatic aldimines in aqueous media

Article abstract of DOI:10.1055/s-2004-816004

The intermolecular additions of alkyl halides to per- (or poly)fluorophenyl aromatic aldimines using zinc as a single-electron-transfer radical initiator have been studied in aqueous media. The reaction proceeds well for imines with different substituents at room temperature under air atmosphere and the corresponding fluorine-containing amines and 1,2-diamines are obtained in poor to good yields. A tentative reaction mechanism is proposed.

Full text of DOI:10.1055/s-2004-816004

PAPER
683
Zinc-Mediated Radical Reactions of Per- (or Poly)fluorophenyl Aromatic
Aldimines in Aqueous Media
Zinc-Mediated
R
ad
i
ical Re
n
actions yuan Liu,a,b Shizheng Zhu,*b Shaowu Wang*a
a
Institute of Organic Chemistry, School of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui, 241000,
P. R. China
E-mail: swwang@mail.ahnu.edu.cn
b
Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu,
Shanghai 200032, P. R. China
Fax +86(21)64166128; E-mail: zhusz@pub.sioc.ac.cn
Received 2 November 2003; revised 7 January 2004
Zn
NHTs
R
NHTs
NTs
Abstract: The intermolecular additions of alkyl halides to per- (or
poly)fluorophenyl aromatic aldimines using zinc as a single-elec-
tron-transfer radical initiator have been studied in aqueous media.
The reaction proceeds well for imines with different substituents at
room temperature under air atmosphere and the corresponding
fluorine-containing amines and 1,2-diamines are obtained in poor to
good yields. A tentative reaction mechanism is proposed.
+
+
RI
Sat. NH4Cl, CH2Cl2
25 °C
Ar
Ar
Ar
Scheme 1
media can be overcome by using per- (or poly)fluorophen-
yl aromatic aldimines in place of simple imines. In com-
parison to simple aldimines, per- (or poly)fluorophenyl
aromatic aldimines are more electrophilic due to the
strong electron-withdrawing group. Moreover, per- (or
Key words: polyfluororinated amines, imines, zinc, alkyl halides,
radical reactions
Carbon–carbon bond formation is an important methodol- poly)fluorophenyl aromatic aldimines are more stable to
ogy for the synthesis of nitrogen-containing biologically hydrolysis than the simple aldimines. We therefore inves-
active compounds. The addition of a variety of carbon nu- tigated the metal-mediated alkylation of per- (or poly)fluor-
cleophiles to carbonyl compounds has been extensively ophenyl aromatic aldimines in aqueous media and
investigated and well established. However, considerably obtained a variety of fluorine-containing amines, which
less successful results were obtained in the reactions of are now widely recognized as important organic materials
nucleophiles with imines. The major problem is the rela- showing potential applications in medicinal and agricul-
tively low reactivity of unactivated imines towards nu- tural scientific fields for their biological activities.13–16
cleophilic addition and deprotonation of imines derived
To a mixture of aldimine 1, isopropyl iodide (2a), zinc
powder, and a small amount of dichloromethane as a co-
solvent was added dropwise a saturated solution of aque-
from enolizable carbonyl compounds to form ena-
mines.1–3
The use of water as a solvent has generated considerable ous NH4Cl over 30 minutes at 25 °C, and then stirred
interest from the economical and environmental points of overnight. After purification by column chromatography
view.4 Particularly, the carbon–carbon bond formation in using hexane as eluent, the isopropylated products 3 were
aqueous media is a challenging problem.5
obtained in poor to good yields along with the coupled di-
amines 4 as by-products (Scheme 2).
The carbon–nitrogen double bond has emerged as a radi-
cal acceptor, and thus numerous synthetically useful car- According to the results summarized in Table 1, the sub-
bon–carbon bond forming reactions are available.6 To the stituents of imine have an influence on these radical addi-
best of our knowledge, the intermolecular radical reaction tion reactions. The nitrogen substitutent R2 can be varied
of imine derivatives has not been widely investigated ex- from the monofluorophenyl group (e.g. 1f) to the strongly
cept for a few examples.7,8 Recently Naito reported an in- activating pentafluorophenyl group (e.g. 1b). It is ob-
termolecular radical reaction between electron deficient served that the more electron-withdrawing the groups on
N-sulfonylimines and alkyl iodide initiated by zinc pow- R2, the higher the yield of the adductive products (entries
der in aqueous media (Scheme 1).9
2–6). The reaction of N-pentafluorophenyl-pentafluor-
ophenyl aldimine (1a) with isopropyl iodide (2a) gave the
expected isopropyl amine 3a exclusively (entry 1), which
should be attributed to the strong electron-withdrawing
ability of two pentafluorophenyl group in 1a and its stabil-
ity in acidic reaction conditions. On the other hand the re-
action of N-(2-fluoro)phenyl-phenyl aldimine (1f) with 2a
gave the expected isopropylated amine 3f and the reduced
coupling product 4f in 26% and 46% yield, respectively
(entry 6).
The analogous aqueous alkylation of inactivated imines
has not been much studied mainly due to the instability of
imines towards hydrolysis.10–12 It is our expectation that
the difficulty associated with the C=N bond in aqueous
SYNTHESIS 2004, No. 5, pp 0683–0691
Advanced online publication: 09.03.2004
DOI: 10.1055/s-2004-816004; Art ID: F11403SS
© Georg Thieme Verlag Stuttgart · New York
x
x
.
x
x
.2
0
0
4

684
X. Liu et al.
PAPER
R2
H
R1
H
R2
N
R2
H
N
Zn, Sat. NH4Cl
CH2Cl2, 25 °C
N
+
R2
+
I
N
R1
R1
R1
4
1
2a
3
h: R1 = 4-CH3C6H4, R2 = 4-ClC6F4
i: R1 = 4-CH3OC6H4, R2 = 4-ClC6F4
j: R1 = 4-BrC6H4, R2 = 4-ClC6F4
k: R1 = 2-BrC6H4, R2 = 4-ClC6F4
l: R1 = 2-ClC6H4, R2 = 4-ClC6F4
m: R1 = 4-NO2C6H4, R2 = 4-ClC6F4
n: R1 = 2-HOC6H4, R2 = 4-ClC6F4
a: R1 = C6F5, R2 = C6F5
b: R1 = C6H5, R2 = C6F5
c: R1 = C6H5, R2 = 4-ClC6F4
d: R1 = C6H5, R2 = 2,4-F2C6H3
e: R1 = C6H5, R2 = 3-Cl,4-FC6H3
f: R1 = C6H5, R2 = 2-FC6H5
g: R1 = C6F5, R2 = C6H5
Scheme 2
Table 1 The Results of the Reaction of 1 with i-PrI and Zna
that the reaction of N-(4-chloro-2,3,5,6-tetrafluoro)phe-
nyl-2-hydroxyphenyl aldimine (1n) which has an elec-
tron-donating group OH on R1 did not give the expected
alkylated product, possibly due to the instability of the de-
sired product (entry 14). The above results indicated that
the substituents on R1 and R2 affect the reactions, and
electron-withdrawing substituents on the group R2 will fa-
vor the addition product.
Entry
Imine
Products and Yield (%)b
3
4
1
2
1a
1b
1c
1d
1e
1f
85
60
74
58
36
26
51
58
50
40
42
48
0
0
20
8
3
The 1,2-diamine functionality can be found in many natu-
ral products, especially peptides, with valuable biological
and therapeutic properties.17 In recent years, several syn-
thetic diamine derivatives have also been employed as
medicinal agents, in particular in chemotherapy.18 More-
over, enantiomerically pure vicinal diamines are also used
increasingly in stereoselective organic synthesis as chiral
auxiliaries or as metal ligands in catalytic asymmetric
synthesis.17,18 Given the significance of 1,2-diamines, a
large number of methods for synthesis of these derivatives
have been developed. The formation of diamines in an
aqueous solution is particularly interesting; since usually
dimerization of aldimines proceeds under anhydrous con-
ditions.19 According to the results summarized in Table 1,
it was found that the more electron-withdrawing the
groups on R2, the lower the yield of the corresponding 1,2-
diamines products. However, some reactions were very
complicated and 1,2-diamines were also formed, which
could not be separated from each other and characterized
with certainty. To probe the formation of the coupled di-
amines, the imine 1b or 1d was treated with zinc powder
in aqueous NH4Cl solution at room temperature without
addition of alkyl iodide. It was observed that the reaction
of 1d with zinc gave the 1,2-diamine 4d exclusively,
while 1b gave nearly equival amount of the reductive
product 5b and 1,2-diamine 4b (Scheme 3). The results
are summarized in Table 2.
4
40
30
46
5
6
c
7
1g
1h
1i
–
8
28
c
9
–
c
10
11
12
13
14
1j
–
c
1k
1l
–
c
–
1m
1n
0
c
0
–
a The reaction was carried out with a mixed solvent and sat. NH4Cl (2
mL) in CH2Cl2 (0.2 mL) at 25 °C. Mole ratio 1/Zn/i-PrI = 1:7:5.
b Isolated yield.
c An unidentified mixture of products was obtained.
The carbon substitutent R1 has, on the other hand, a strong
influence on the reactivity of the imine. Under similar re-
action conditions, the preparation of N-phenyl-pentafluor-
ophenyl aldimine (1g) worked well and the alkylated
product of N-(1-pentafluorophenyl-2-methylpropyl)phe-
nylamine (3g) was obtained in 51% yield (entry 7). In
contrast to 1a–1l, when N-(4-chloro-2,3,5,6-tetra-
fluoro)phenyl-4-nitrophenyl aldimine (1m) was used to
react with isopropyl iodide (2a), no reaction occurred to
give the corresponding product, but only 1m was decom-
posed in the presence of acidic reaction conditions to pro-
vide a mixture of compounds (entry 13). It was surprising
R1
R2
H
H
R2
N
Zn
R2
H
+
N
N
R2
N
R1
R1
Sat. NH4Cl, CH2Cl2
R1
1b or 1d
5
4
Scheme 3
Synthesis 2004, No. 5, 683–691 © Thieme Stuttgart · New York

PAPER
Zinc-Mediated Radical Reactions
685
Table 2 Reaction of 1 with Zinc in Aqueous Media
As allylic amines are key structural elements in a variety
of important naturally occurring molecules20 and
pharmaceuticals21 and are among the most versatile inter-
mediates in the synthesis of other important molecules,22
they have attracted much attention.23 The allylation of
imines, enamines and nitriles to afford homoallylic
amines under Barbier-type conditions is a reaction of
great interest in organic synthesis.24 We originally intend-
ed to probe the synthesis of homoallylic amines by nu-
cleophilic addition of an allyindium reagent formed in situ
from an allyl bromide and indium metal, to per- (or
poly)fluorophenyl aromatic aldimines in alcoholic sol-
vents.25 To our surprise, the allylic alcohol and the 4-chlo-
ro-2,3,5,6-tetrafluoroaniline, were isolated instead of the
imine adduct (Scheme 4). The formation of the homoal-
lylic alcohol is presumably the result of allylation of 4-
methylbenzaldehyde derived from indium salt-catalyzed
hydrolysis of the imine 1g.
Entry Imine 1 R1
R2
Products and Yield (%)a
1
2
1b
1d
Ph
Ph
C6F5
4b
45
5b
5d
40
0
2,4-F2C6H3 4d
100
a Isolated yield.
These new products were fully characterized spectroscop-
ically and the compound 4b was further elucidated by X-
ray crystallographic analysis. Figure 1 shows the X-ray
crystal structure of compound 4b. It is clear that there ex-
ist two chemically nonequivalent molecules in the united
cell (Figure 1). The plane angles of two pentafluorophe-
nyl planes and two phenyl planes are 89.2° and 29.8°, re-
spectively, in the molecule I (–X, Y, 0.5–Z). However, the
angles of two pentafluorophenyl planes and two phenyl
planes are 83.1° and 89.2°, respectively, in another mole-
cule II (–X+1, Y, 0.5–Z).
When zinc powder was used, it was found by TLC moni-
toring that the starting material 1b disappeared after 10
hours at 25 °C and new spots appeared. The products,
however, were not homoallylic alcohol but homoallylic
fluorine-containing amine 6b and 1,2-diamine 4b in 40%
and 20% yields, respectively (Scheme 5).26
Some of these results are shown in Table 3. It was found
that the homoallylic amines and the corresponding 1,2-di-
amines were obtained in poor to moderate yields. The
more electron-withdrawing the groups on R2, the higher
the yield of the addition products (entries1–5). Under sim-
ilar reaction conditions, 1c could also react with benzyl
bromide, the reaction was however very complicated. An
attempt at purifying the product by column chromatogra-
phy failed (entry 6).
We next turned out attention to the effect of media and
alkyl group in the radical addition to the imine. Some re-
sults are shown in Table 4. It was found that the methylat-
ed product was not obtained in the reaction using a less
reactive methyl radical because of the competitive hydrol-
ysis and reduction (entry 2).9 It was noteworthy that no re-
action occurred in the absence of aqueous NH4Cl (entry
3). In contrast, the exclusive adduct 3c was isolated and
the homocoupled product was not obtained in aqueous
NH4Cl without CH2Cl2 at room temperature (entry 4).
The known examples of metal-mediated carbon–carbon
bond forming reactions in aqueous media are mainly lim-
ited to alkylation of carbonyl compounds.27 It should be
pointed out that the alkylation of imine derivatives go
Figure 1 X-ray crystal structure of compound 4b
F
F
Cl
F
F
OH
In
Br
N
Cl
+
NH2
F
+
MeOH
F
F
F
2b
1g
Scheme 4
Synthesis 2004, No. 5, 683–691 © Thieme Stuttgart · New York

686
X. Liu et al.
PAPER
R2
R1
H
H
N
Zn
R2
N
+
R2
Br
N
+
R2
N
Sat. NH4Cl, CH2Cl2
25 °C
R1
R1
R1
H
6
1
4
2b
Scheme 5
should be formed first. The species could attack another
molecule 1 to give D or further reduce to form the anion
E, protonation of the intermediate D or E give the product
4 or 5.
Table 3 Zinc-Mediated Radical Addition to 1b–f with Allyl Bro-
mide in Aqueous Mediaa
Entry
Imine
1b
1c
Products and Yield (%)b
1
6b
6c
6d
6e
6f
40
30
32
34
21
0
4b
4c
4d
4e
4f
20
30
30
34
50
33
In conclusion, we have demonstrated per- (or poly)fluor-
ophenyl aromatic aldimines can act as radical acceptors in
aqueous media. These are the first examples of the reac-
tion of per- (or poly)fluorophenylaromatic imines with
carbon radicals. The alkylated or coupled product could
be isolated depending on the solvents and constituent
groups on R1 and R2 of the substrates. This reaction pro-
vides a convenient method for preparing a wide range of
fluorine-containing amine derivatives. Further utility of
this reaction is in progress.
2
3
1d
1e
4
5
1f
6c
1c
6c
4c
a Reaction was carried out with a mixed solvent and sat. NH4Cl (2
mL) in CH2Cl2 (0.2 mL) at 25 °C, the mole ratio of 1:Zn:allyl bromide
is 1:7:5.
b Isolated yield.
Melting points were measured in Temp-Melt apparatus and are un-
corrected. 1H, 13C and 19F NMR spectra were recorded in CDCl3 on
Bruker AM-300 instruments with Me4Si and CFCl3 (with upfield
negative) as the internal and external standards, respectively. IR
spectra were obtained with a Nicolet AV-360 spectrophotometer.
Low-resolution and high-resolution mass spectra (HRMS) were ob-
tained on a Finnigan GC-MS 4021 or a Finnigan MAT-8430 instru-
ment using the electron impact ionization technique (70 eV),
respectively. Elemental analyses data were obtained on a Perkin
Elmer 2400 series II Elemental Analyzer. All reactions as well as
column chromatography were monitored routinely with the aid of
TLC or 19F NMR spectroscopy. Compounds 1a–n were prepared
according to the procedures reported.29
c Reaction of 1c (50 mg) was carried out with Zn (7 equiv), benzyl
bromide (5 equiv), and aq sat. NH4Cl (1 mL) in CH2Cl2 (0.1 mL) at
25 °C.
though an organometallic species in aqueous media is im-
probable. Zinc powder-mediated radical reaction mecha-
nism of electron deficient N-sulfonylimine and aldehyde
had been proposed.9,28 On the basis of the above evidenc-
es, a tentative mechanism for the reaction is proposed in
Scheme 6. The alkylation should proceed via a single
electron transfer from the metal to the halide followed by
the addition of the formed alkyl radical to the carbon–ni-
trogen double bond of per- (or poly)fluorophenyl ald-
imines 1, producing a radical intermediate A, which was
further reduced by the metal to form the anion B, protona-
tion of the anion gave product 3 or 6. While, for the for-
mation of the 1,2-diamines, the radical intermediate C
Radical Reaction of Imines 1 with Isopropyl Iodide (2a); Gener-
al Procedure
To a mixture of 1a (0.1 g, 0.28 mmol) and i-PrI 2a (0.235 g, 1.40
mmol, 5 equiv) and zinc (0.127 g, 1.96 mmol, 7 equiv) in CH2Cl2
(0.2 mL) was added dropwise a sat. solution of aq NH4Cl (2 mL)
over 30 min at 25 °C and then stirred overnight at 25 °C. The reac-
tion mixture was poured into a sat. solution of aq NaHCO3, and ex-
tracted with CH2Cl2 (3 × 10 mL). The organic layer was washed
with brine, dried (Na2SO4), and the solvent was removed in vacuo.
Table 4 Reaction of 1c with RI under Different Reaction Conditions
Entry
R
Reaction Conditions
Products and Yield (%)a
Solvents
Time (h)
3c
4c
8
1b
i-PrI
MeI
i-PrI
i-PrI
sat. NH4Cl4/CH2Cl2 (10:1)
Sat. NH4Cl4/CH2Cl2 (10:1)
CH2Cl2
10
10
10
10
74
2
0
20
3
no reaction
80
4c
Sat. NH4Cl4
0
a Isolated yield.
b Data from Table 1, entry 3.
c On the basis of the recovered imine 1c.
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PAPER
Zinc-Mediated Radical Reactions
687
RX
Zn
R2
R2
R2
H+
Zn
N
N
R
N
3 or 6
R1
R
R1
R
R1
1
B
A
R1
H+
ZnX
R1
R2
N
N
4
R2
R2
-
N
R2
R1
XZn
R1
R2
ZnX
Zn
Zn
N
Zn
N
D
NH4Cl
R1
XZn
H+
R2
N
5
C
1
-
R1
E
Scheme 6
2
The product 3a was isolated by flash column chromatography on
silica gel using hexane as eluent.
13C NMR (CDCl3): d = 19.4, 19.8, 35.3, 65.9, 99.5 (t, JC,F = 19.4
2
Hz), 126.6 (t, JC,F = 19.4 Hz), 126.7, 127.4, 128.5, 139.6 (m,
1JC,F = 239.2 Hz), 142.77, 144.6 (m, 1JC,F = 244.1 Hz).
N-Pentafluorophenyl-N-(1-pentafluorophenyl-2-methylpro-
pyl)amine (3a)
Colorless oil.
IR (neat): 3412, 2972, 1655, 1523, 1502, 1112 cm–1.
1H NMR (CDCl3): d = 0.89 (3 H, d, J = 6.9 Hz, CH3), 1.26 (3 H, d,
J = 6.6 Hz, CH3), 2.23 (1 H, oct, J = 6.9 Hz, CH), 4.11 (1 H, d,
J = 11.1 Hz, NH), 4.70 (1 H, dd, J = 11.1 Hz, 6.9 Hz, CH).
MS (EI): m/z (%) = 333 (M+ + 2, 1), 331 (M+, 3), 291 (5), 290 (33),
289 (15), 288 (100), 212 (11), 210 (30), 91 (25), 77 (7).
Anal. Calcd for C16H14ClF5N: C, 57.93; H, 4.25; N, 4.25. Found: C,
58.19; H, 4.18; N, 4.01.
N-(2,4-Difluorophenyl)-N-(2-methyl-1-phenylpropyl)amine
(3d)
Colorless oil.
19F NMR (CDCl3): d = –144.1 (2 F, d, 3JF,F = 16.1 Hz), –154.8 (1 F,
t, 3JF,F = 14.7 Hz), –158.6 (2 F, d, 3JF,F = 16.9 Hz), –161.5 (2 F, m),
–163.7 (2 F, t, 3JF,F = 18.6 Hz), –169.3 (1 F, t, 3JF,F = 17.8 Hz).
MS (EI): m/z (%) = 405 (M+, 5), 363 (15), 362 (100), 194 (16), 181
(15).
IR (neat): 3444, 2962, 1601, 1520, 1268, 1213, 1093 cm–1.
1H NMR (CDCl3): d = 0.92 (3 H, d, J = 6.9 Hz, CH3), 1.01 (3 H, d,
J = 6.6 Hz, CH3), 2.05 (1 H, oct, J = 6.6 Hz, CH), 4.06 (1 H, t,
J = 6.6 Hz, CH), 4.20 (1 H, br s, NH), 6.25–6.33 (1 H, m, Ar), 6.50–
6.57 (1 H, m, Ar), 6.71–6.78 (1 H, m, Ar), 7.19–7.34 (5 H, m, Ar).
19F NMR (CDCl3): d = –126.7 (1 F, q, J = 6.8 Hz), –132.8 (1 F, t,
J = 9.0 Hz).
Anal. Calcd for C16H9F10N: C, 47.42; H, 2.24; N, 3.46. Found: C,
47.80; H, 2.14; N, 3.40.
N-Pentafluorophenyl-N-(2-methyl-1-phenylpropyl)amine (3b)
Slightly yellowish oil.
IR (neat): 3140, 2964, 1523, 1469, 1455, 1010 cm–1.
1H NMR (CDCl3): d = 0.82 (3 H, d, J = 6.9 Hz, CH3), 1.13 (3 H, d,
J = 6.6 Hz, CH3), 1.98 (1 H, oct, J = 6.6 Hz, CH), 3.96 (1 H, d,
J = 9.9 Hz, NH), 4.30 (1 H, dd, J = 9.9, 6.6 Hz, CH), 7.13–7.30 (5
H, m, Ar).
MS (EI): m/z (%) = 261 (M+, 12), 219 (18), 218 (100), 140 (25), 91
(14), 77 (7).
Anal. Calcd for C16H17F2N: C, 73.54; H, 6.57; N, 5.36. Found: C,
73.91; H, 6.74; N, 5.24.
N-(3-Chloro-4-fluorophenyl)-N-(2-methyl-1-phenylpro-
pyl)amine (3e)
Slightly yellowish oil.
IR (neat): 3434, 2962, 1610, 1504, 1221, 1050 cm–1.
19F NMR (CDCl3): d = –157.8 (2 F, d, 3JF,F = 23.1 Hz), –164.4 (2 F,
t, 3JF,F = 22.3 Hz), –170.9 (1 F, t, 3JF,F = 22.3 Hz).
MS (EI): m/z (%) = 315 (M+, 3), 273 (15), 272 (100), 194 (34), 91
(17), 77 (6).
1H NMR (CDCl3): d = 0.82 (3 H, d, J = 6.6 Hz, CH3), 0.90 (3 H, d,
J = 6.6 Hz, CH3), 1.93 (1 H, oct, J = 6.6 Hz, CH), 3.90–3.98 (2 H,
m, NH and CH), 6.19–6.24 (1 H, m, Ar), 6.40–6.44 (1 H, m, Ar),
6.70–6.76 (1 H, m, Ar), 7.11–7.25 (5 H, m, Ar).
Anal. Calcd for C16H14F5N: C, 60.95; H, 4.44; N, 4.48. Found: C,
61.33; H, 4.44; N, 4.87.
19F NMR (CDCl3): d = –131.8 (1 F, t, J = 9.5 Hz).
N-[(4-Chloro)tetrafluorophenyl]-N-(2-methyl-1-phenylpro-
pyl)amine (3c)
Slightly yellowish oil.
IR (neat): 3419, 2964, 1645, 1499, 1464, 1146 cm–1.
1H NMR (CDCl3): d = 0.83 (3 H, d, J = 6.6 Hz, CH3), 1.12 (3 H, d,
J = 6.6 Hz, CH3), 1.99 (1 H, oct, J = 6.6 Hz, CH), 4.19 (1 H, d,
J = 9.6 Hz, NH), 4.40 (1 H, dd, J = 9.6, 6.6 Hz, CH), 7.15–7.31 (5
H, m, Ar).
MS (EI): m/z (%) = 279 (M+ +2, 3), 277 (M+, 8), 236 (33), 235 (16),
234 (100), 158 (4), 156 (12), 91 (7), 77 (3).
Anal. Calcd for C16H17ClFN: C, 69.19; H, 6.17; N, 5.04. Found: C,
69.62; H, 6.48; N, 4.86.
N-(2-Fluorophenyl)-N-(2-methyl-1-phenylpropyl)amine (3f)
Colorless oil.
IR (neat): 3446, 2962, 1620, 1521, 1452, 1335, 1247 cm–1.
1H NMR (CDCl3): d = 0.95 (3 H, d, J = 6.9 Hz, CH3), 1.03 (3 H, d,
J = 6.6 Hz, CH3), 2.09 (1 H, oct, J = 6.6 Hz, CH), 4.14 (1 H, t,
19F NMR (CDCl3): d = –143.8 (2 F, d, 3JF,F = 19.2 Hz), –157.1 (2 F,
d, 3JF,F = 19.2 Hz).
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688
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J = 6.6 Hz, CH), 4.42 (1 H, br s, NH), 6.39–6.99 (4 H, m, Ar), 7.23–
7.34 (5 H, m, Ar).
19F NMR (CDCl3): d = –143.4 (2 F, d, 3JF,F = 16.9 Hz), –157.1 (2 F,
d, 3JF,F = 16.9 Hz).
19F NMR (CDCl3): d = –137.1 (1 F, m).
MS (EI): m/z (%) = 243 (M+, 7), 201 (15), 201 (100), 122 (23), 91
MS (EI): m/z (%) = 413 (M+ + 4, 1), 411 (M+ + 2, 3), 409 (M+, 2),
370 (27), 368 (100), 366 (76), 212 (11), 210 (28).
HRMS: m/z calcd for C16H13BrClF4N (M+): 408.98765; found:
(8), 77 (6).
408.98560.
Anal. Calcd for C16H18FN: C, 78.98; H, 7.46; N, 5.76. Found: C,
79.16; H, 7.18; N, 5.66.
N-[1-(2-Bromophenyl)-2-methylpropyl]-N-[(4-chloro)tetra-
fluorophenyl]amine (3k)
Slightly yellowish oil.
IR (neat): 3423, 2964, 1645, 1499, 1468, 1148 cm–1.
1H NMR (CDCl3): d = 0.85 (3 H, d, J = 6.9 Hz, CH3), 1.10 (3 H, d,
J = 6.6 Hz, CH3), 1.96 (1 H, oct, J = 6.6 Hz, CH), 4.16 (1 H, d,
J = 9.6 Hz, NH), 4.37 (1 H, dd, J = 9.6 Hz, 6.6 Hz), 7.09–7.20 (2
H, m, Ar), 7.33–7.38 (2 H, m, Ar).
N-(1-Pentafluorophenyl-2-methylpropyl)-N-phenylamine (3g)
Slightly yellowish oil.
IR (neat): 3416, 2967, 1604, 1500, 1299, 1109 cm–1.
1H NMR (CDCl3): d = 0.88 (3 H, d, J = 6.6 Hz, CH3), 1.19 (3 H, d,
J = 6.6 Hz, CH3), 2.18 (1 H, oct, J = 6.6 Hz, CH), 4.09 (1 H, d,
J = 10.8 Hz, NH), 4.49 (1 H, dd, J = 10.8, 6.6 Hz, CH), 6.57–6.72
(3 H, m, Ar), 7.11–7.16 (2 H, m, Ar).
19F NMR (CDCl3): d = –143.4 (2 F, d, 3JF,F = 18.6 Hz), –157.2 (2 F,
19F NMR (CDCl3): d = –144.3 (2 F, d, 3JF,F = 24.3 Hz), –156.0 (1 F,
d, 3JF,F = 15.0 Hz).
t, 3JF,F = 23.4 Hz), –162.2 (2 F, m).
MS (EI): m/z (%) = 413 (M+ + 4, 1), 411 (M+ + 2, 4), 409 (M+, 3),
370 (25), 369 (17), 368 (100), 367 (23), 366 (79), 212 (13), 210
(28).
MS (EI): m/z (%) = 315 (M+, 13), 272 (100), 273 (16), 181 (4), 77
(19).
HRMS: m/z calcd for C16H14F5N (M+): 315.10547; found:
315.10464.
Anal. Calcd for C16H13BrClF4N: C, 46.80; H, 3.19; N, 3.41. Found:
C, 47.09; H, 3.09; N, 3.21.
N-[(4-Chloro)tetrafluorophenyl]-N-[1-(4-methylphenyl)-2-me-
thylpropyl]amine (3h)
Colorless oil.
IR (neat): 3416, 2963, 1644, 1510, 1463, 1141 cm–1.
1H NMR (CDCl3): d = 0.83 (3 H, d, J = 6.3 Hz, CH3), 1.11 (3 H, d,
J = 6.6 Hz, CH3), 1.98 (1 H, oct, J = 6.6 Hz, CH), 2.30 (3 H, s,
CH3), 4.17 (1 H, d, J = 10.5 Hz, NH), 4.36 (1 H, dd, J = 10.5 Hz,
6.6 Hz), 7.06 (4 H, d, J = 8.1 Hz, Ar).
N-[1-(2-Cholophenyl)-2-methylpropyl]-N-[(4-chloro)tetra-
fluorophenyl]amine (3l)
Colorless oil.
IR (neat): 3354, 2967, 1644, 1500, 1362, 1221 cm–1.
1H NMR (CDCl3): d = 0.97 (3 H, d, J = 6.6 Hz, CH3), 1.11 (3 H, d,
J = 6.9 Hz, CH3), 2.20 (1 H, oct, J = 6.6 Hz, CH), 4.37 (1 H, d,
J = 9.9 Hz, NH), 4.94 (1 H, dd, J = 9.9, 6.9 Hz, CH), 7.15–7.37 (4
H, m, Ar).
19F NMR (CDCl3): d = –143.9 (2 F, d, 3JF,F = 18.6 Hz), –157.1 (2 F,
19F NMR (CDCl3): d = –143.9 (2 F, d, 3JF,F = 19.2 Hz), –157.8 (2 F,
d, 3JF,F = 18.6 Hz).
d, 3JF,F = 19.2 Hz).
MS (EI): m/z (%) = 347 (M+ + 2, 1), 345 (M+, 3), 305 (5), 304 (35),
303 (18), 302 (100), 212 (10), 210 (27), 105 (29).
MS (EI): m/z (%) = 367 (M+ + 2, 2), 365 (M+, 4), 326 (12), 325 (11),
324 (67), 323 (20), 322 (100), 212 (9), 210 (24), 127 (6), 125 (18).
Anal. Calcd for C17H16ClF4N: C, 59.05; H, 4.66; N, 4.05. Found: C,
59.22; H, 5.03; N, 3.93.
Anal. Calcd for C16H13Cl2F4N: C, 52.48; H, 3.58; N, 3.83. Found:
C, 52.68; H, 3.67; N, 3.49.
N-[(4-Chloro)tetrafluorophenyl]-N-[1-(4-methoxyphenyl)-2-
methylpropyl]amine (3i)
Slightly yellowish oil.
Reaction of Imines 1 with in situ Generated Allyl Radical from
Allyl Bromide (2a); General Procedure
To a mixture of 1b (0.1 g, 0.40 mmol) and allyl bromide (2b; 0.218
g, 1.80 mmol, 5 equiv) and zinc (0.183 g, 2.80 mmol, 7 equiv) in
CH2Cl2 (0.2 mL) was added dropwise an aq sat. solution of NH4Cl
(2 mL) over 30 min at 25 °C, and the mixture was stirred overnight
at 25 °C. The mixture was then poured into aq sat. solution of
NaHCO3, and extracted with CH2Cl2 (3 × 10 mL). The organic lay-
er was washed with brine, dried (Na2SO4), and the solvent was re-
moved in vacuo. The product was isolated by flash column
chromatography on silica gel with hexane as eluent.
IR (neat): 3427, 2963, 1504, 1462, 1261, 1093-1025 cm–1.
1H NMR (CDCl3): d = 0.74 (3 H, d, J = 6.9 Hz, CH3), 1.04 (3 H, d,
J = 6.6 Hz, CH3), 1.88 (1 H, oct, J = 6.6 Hz, CH), 3.70 (3 H, s,
OCH3), 4.07 (1 H, d, J = 10.5 Hz, NH), 4.27 (1 H, dd, J = 10.5 Hz,
6.6 Hz), 6.73 (2 H, d, J = 8.1 Hz, Ar), 7.00 (2 H, d, J = 8.1 Hz, Ar).
19F NMR (CDCl3): d = –143.9 (2 F, d, 3JF,F = 16.9 Hz), –157.0 (2 F,
d, 3JF,F = 16.9 Hz).
MS (EI): m/z (%) = 361 (M+, 2), 321 (6), 320 (34), 319 (22), 318
(100), 212 (6), 210 (15), 121 (24).
N-Pentafluorophenyl-N-(1-phenylbut-3-enyl)amine (6b)
Colorless oil.
HRMS: m/z calcd for C17H16ClF4N (M+): 361.08170; found:
IR (neat): 3401, 3084, 1520, 1457, 1002, 968 cm–1.
361.08566.
1H NMR (CDCl3): d = 2.61 (2 H, t, J = 6.9 Hz, CH2), 4.04 (1 H, d,
J = 9.3 Hz, NH), 4.73–4.80 (1 H, m, CH), 5.15–5.24 (2 H, m,
CH2=), 5.69–5.83 (1 H, m, CH=), 7.22–7.36 (5 H, m, Ar).
N-[1-(4-Bromophenyl)-2-methylpropyl]-N-[(4-chloro)tetra-
fluorophenyl]amine (3j)
Slightly yellowish oil.
IR (neat): 3368, 2972, 1644, 1511, 1488, 1463, 1118 cm–1.
1H NMR (CDCl3): d = 0.83 (3 H, d, J = 6.9 Hz, CH3), 1.11 (3 H, d,
J = 7.2 Hz, CH3), 1.96 (1 H, oct, J = 6.9 Hz, CH), 4.15 (1 H, d,
J = 9.6 Hz, NH), 4.36 (1 H, dd, J = 9.6, 6.9 Hz), 7.04 (2 H, d,
J = 8.1 Hz, Ar), 7.42 (2 H, d, J = 8.1 Hz, Ar).
19F NMR (CDCl3): d = –158.2 (2 F, d, 3JF,F = 21.2 Hz), –164.5 (2 F,
t, 3JF,F = 19.7 Hz), –170.8 (1 F, m).
MS (EI): m/z (%) = 313 (M+, 1), 273 (17), 272 (100), 194 (16), 91
(10), 77 (5).
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Zinc-Mediated Radical Reactions
689
Anal. Calcd for C16H12F5N: C, 61.35; H, 3.86; N, 4.47. Found: C,
61.35; H, 3.86; N, 4.72.
N,N¢-Bis[(4-chloro)tetrafluorophenyl]-1,2-bis(4-methylphen-
yl)-1,2-ethylenediamne (4h)
This compound was obtained as a by-product and isolated by flash
column chromatography on silica gel using EtOAc–hexane (1:80)
as eluent; white solid; mp 178–180 °C.
N-[(4-Chloro)tetrafluorophenyl]-N-(1-phenylbut-3-enyl)amine
(6c)
Colorless oil.
IR (KBr): 3359, 2940, 1644, 1513, 1489, 1143 cm–1.
IR (neat): 3404, 3083, 1644, 1499, 1460, 1149, 962 cm–1.
1H NMR (CDCl3): d = 2.30 (6 H, s, CH3), 4.51 (2 H, br s, NH), 5.04
(2 H, d, J = 8.1 Hz, CH), 6.82 (4 H, d, J = 8.1 Hz, Ar), 7.03 (4 H,
d, J = 8.1 Hz, Ar).
1H NMR (CDCl3): d = 2.63 (2 H, t, J = 6.9 Hz, CH2), 4.29 (1 H, d,
J = 9.0 Hz, NH), 4.82–4.90 (1 H, m, CH), 5.17–5.25 (2 H, m,
CH2=), 5.69–5.83 (1 H, m, CH=), 7.24–7.37 (5 H, m, Ar).
19F NMR (CDCl3): d = –143.9 (2 F, d, 3JF,F = 18.3 Hz), –157.6 (2 F,
d, J = 18.3 Hz).
19F NMR (CDCl3): d = –143.4 (4 F, d, 3JF,F = 15.8 Hz), –156.6 (4 F,
d, 3JF,F = 15.8 Hz).
13C NMR (CDCl3): d = 21.1, 63.8, 101.1, 125.3, 127.5, 129.3,
13C NMR (CDCl3): d = 42.8, 58.5, 99.8 (t, JC,F = 18.6 Hz), 118.9,
134.1, 138.1, 138.2 (m, JC,F = 233.5 Hz), 144.4 (m, JC,F = 233.5
2
1
1
2
125.9 (t, JC,F = 11.4 Hz), 126.0, 127.6, 128.7, 133.5, 140.1 (m,
Hz).
1JC,F = 240.1 Hz), 142.3, 145.1 (m, 1JC,F = 244.3 Hz).
Ms (EI): m/z (%) = 305 (5), 304 (33), 303 (17), 302 (100), 212 (8),
210 (24).
MS (EI): m/z (%) = 329 (M+, 1), 290 (33), 289 (22), 288 (100), 212
(11), 210 (33), 91 (10), 77 (8).
HRMS: m/z calcd for C28H18Cl2F8N2 (M+ – C14H9ClF4N):
Anal. Calcd for C16H12ClF4N: C, 58.28; H, 3.67; N, 4.25. Found: C,
58.38; H, 3.66; N, 4.55.
302.0353450; found: 302.0354162.
N,N¢-Bis(pentafluorophenyl)-1,2-diphenyl-1,2-ethylenedi-
amine (4b)
N-(2,4-Difluorophenyl)-N-(1-phenylbut-3-enyl)amine (6d)
Colorless oil.
White solid; mp 109–110 °C.
IR (neat): 3426, 3081, 1520, 1429, 1266, 1142, 1094 cm–1.
IR (KBr): 3362, 3065, 1519, 1166, 1016, 973 cm–1.
1H NMR (CDCl3): d = 2.49–2.70 (2 H, m, CH2), 4.30 (1 H, br s,
NH), 4.33–4.39 (1 H, m, CH), 5.17–5.27 (2 H, m, CH2=), 5.73–5.85
(1 H, m, CH=), 6.27–6.60 (2 H, m, Ar), 6.75––6.82 (1 H, m, Ar),
7.25–7.39 (5 H, m, Ar).
19F NMR (CDCl3): d = –126.4 (1 F, d, J = 9.6 Hz), –132.5 (1 F, t,
J = 9.0 Hz).
1H NMR (CDCl3): d = 4.42 (2 H, br s, NH), 4.96 (2 H, d, J = 7.5 Hz,
CH), 6.94–6.97 (4 H, m, Ar), 7.20–7.25 (6 H, m, Ar).
19F NMR (CDCl3): d = –157.1 (4 F, d, 3JF,F = 22.0 Hz), –164.0 (4 F,
t, 3JF,F = 21.2 Hz), –169.1 (2 F, m).
MS (EI): m/z (%) 273 (15), 272 (100), 194 (25), 77 (6).
Anal. Calcd for C26H14F10N2: C, 57.35; H, 2.59; N, 5.14. Found: C,
57.54; H, 2.51; N, 5.05.
MS (EI): m/z (%) = 259 (M+, 4), 219 (17), 218 (100), 140 (32), 91
(7), 77 (7).
Anal. Calcd for C16H15F2N: C, 74.11; H, 5.83; N, 5.40. Found: C,
74.33; H, 5.97; N, 5.18.
N,N¢-Bis[(4-chloro)tetrafluorophenyl]-1,2-diphenyl-1,2-ethyl-
enediamine (4c)
White solid; mp 120–121 °C.
N-(3-Chloro-4-fluorophenyl)-N-(1-phenylbut-3-enyl)amine(6e)
Colorless oil.
IR (neat): 3417, 3063, 1610, 1504, 1228 cm–1.
1H NMR (CDCl3): d = 2.44–2.68 (2 H, m, CH2), 4.14 (1 H, d,
J = 4.2 Hz, NH), 4.30–4.36 (1 H, m, CH), 5.18–5.26 (2 H, m,
CH2=), 5.70–5.82 (1 H, m, CH=), 6.29–6.34 (1 H, m, Ar), 6.51–6.54
(1 H, m, Ar), 6.83–6.89 (1 H, m, Ar), 7.25–7.40 (5 H, m, Ar).
19F NMR (CDCl3): d = –131.6 (1 F, s).
MS (EI): m/z (%) = 277 (M+ + 2, 1), 275 (M+, 3), 237 (5), 236 (33),
IR (KBr): 3364, 2940, 1645, 1517, 1491, 1150 cm–1.
1H NMR (CDCl3): d = 4.59 (2 H, br s, NH), 5.02 (2 H, d, J = 8.1 Hz,
CH), 6.70–7.27 (10 H, m, Ar).
19F NMR (CDCl3): d = –142.9 (4 F, d, 3JF,F = 17.5 Hz), –156.12 (4
F, d, 3JF,F = 17.5 Hz).
MS (EI): m/z (%) = 291 (5), 290 (33), 289 (16), 288 (100), 212 (10),
210 (30), 77 (6).
Anal. Calcd for C26H14Cl2F8N2: C, 54.09; H, 2.44; N, 4.85. Found:
C, 54.02; H, 2.34; N, 4.70.
235 (16), 234 (100), 158 (5), 156 (14), 91 (5), 77 (3).
Anal. Calcd for C16H15ClFN: C, 69.69; H, 5.48; N, 5.08. Found: C,
69.88; H, 5.38; N, 4.91.
N,N¢-Bis(2,4-difluorophenyl)-1,2-diphenyl-1,2-ethylenedi-
amine (4d)
White solid; mp 110–111 °C.
N-(2-Fluorophenyl)-N-(1-phenylbut-3-enyl)amine (6f)
Colorless oil.
IR (neat): 3427, 3066, 1621, 1513, 1452, 1335, 1188 cm–1.
1H NMR (CDCl3): d = 2.54–2.73 (2 H, m, CH2), 4.41–4.47 (1 H, m,
CH), 4.51 (1 H, br s, NH), 5.20–5.29 (2 H, m, CH2=), 5.76–5.89 (1
H, m, CH=), 6.40–7.43 (9 H, m, Ar).
19F NMR (CDCl3): d = –136.9 (1 F, s).
IR (KBr): 3410, 3028, 1517, 1265, 1087, 960 cm–1.
1H NMR (CDCl3): d = 4.55 (1 H, d, J = 5.7 Hz, CH), 4.68 (2 H, br
s, NH), 4.92 (1 H, d, J = 8.4 Hz, CH), 6.27–6.40 (2 H, m, Ar), 6.51–
6.58 (2 H, m, Ar), 6.72–6.82 (2 H, m, Ar), 7.12–7.24 (2 H, m, Ar),
7.25–7.27 (6 H, m, Ar).
19F NMR (CDCl3): d = –124.9 (1 F, d, J = 9.0 Hz), –125.2 (1 F, d,
J = 10.8 Hz), –131.2 (1 F, t, J = 9.0 Hz), –131.6 (1 F, t, J = 10.8 Hz).
MS (EI): m/z (%) = 241 (M+, 3), 201 (16), 200 (100), 122 (32), 91
MS (EI): m/z (%) = 219 (16), 218 (100), 140 (16), 77 (3).
(7), 77 (8).
Anal. Calcd for C26H14Cl2F8N2: C, 71.55; H, 4.62; N 6.42. Found:
C, 71.68; H, 4.45; N, 6.26.
Anal. Calcd for C16H16FN: C, 79.64; H, 6.68; N, 5.80. Found: C,
79.63; H, 6.76; N, 5.60.
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X. Liu et al.
PAPER
N,N¢-Bis(3-chloro-4-fluorophenyl)-1,2-diphenyl-1,2-ethylenedi-
amine (4e)
Young Scholars Foundation of Anhui Province for financial sup-
port.
White solid; mp 148–150 °C.
IR (KBr): 3419, 3025, 1500, 1453, 1224, 1048 cm–1.
References
1H NMR (CDCl3): d = 4.46 (1 H, d, J = 6.3 Hz, CH), 4.47 (2 H, br
s, NH), 4.85 (1 H, d, J = 7.5 Hz, CH), 6.31–6.37 (2 H, m, Ar), 6.50–
6.55 (2 H, m, Ar), 6.81–6.94 (4 H, m, Ar), 7.11–7.14 (2 H, m, Ar),
7.24–7.29 (6 H, m, Ar).
(1) Enders, D.; Reinhold, U. Tetrahedron: Asymmetry 1997, 8,
1895.
(2) Bloch, R. Chem. Rev. 1998, 98, 1407.
(3) Kobayashi, S.; Ishitani, H. Chem. Rev. 1999, 99, 1069.
(4) Garner, P. P.; Parker, D. T.; Gajewski, J. J.; Lubineau, A.;
Angé, J.; Queneau, Y.; Beletskaya, I. P.; Cheprakov, A. V.;
Fringuelli, F.; Piermatti, O.; Pizzo, F.; Kobayashi, S.
Organic Synthesis in Water; Grieco, P. A., Ed.; Blackie
Academic Professional: London, 1998.
(5) For reviews, see: (a) Li, C. J. Chem. Rev. 1993, 93, 2023.
(b) Lubineau, A.; Angé, J.; Queneau, Y. Synthesis 1994,
741. (c) Li, C. J. Tetrahedron 1996, 52, 5643.
(6) (a) Naito, T. Heterocycles 1999, 50, 505. (b) Fallis, A. G.;
Brinza, I. M. Tetrahedron 1997, 53, 17543.
(7) (a) Hart, D. J.; Seely, F. J. J. Am. Chem. Soc. 1988, 110,
1631. (b) Miyabe, H.; Ueda, M.; Naito, T. J. Org. Chem.
2000, 65, 5043. (c) Bertrand, M.; Feray, L.; Nouguier, R.;
Perfetti, P. J. Org. Chem. 1999, 64, 9189.
19F NMR (CDCl3): d = –130.1 (2 F, s), –130.4 (2 F, s).
MS (EI): m/z (%) = 237 (6), 236 (41), 235 (20), 234 (100), 158 (6),
156 (16).
Anal. Calcd for C26H20Cl2F2N2: C, 66.53; H, 4.29; N, 5.97. Found:
C, 66.25; H, 4.30; N, 5.61.
N,N¢-Bis(2-fluorophenyl)-1,2-diphenyl-1,2-ethylenediamine
(4f)
White solid; mp 200–201 °C.
IR (KBr): 3397, 3028, 1619, 1509, 1330, 1199 cm–1.
1H NMR (CDCl3): d = 4.63 (1 H, d, J = 5.4 Hz, CH), 4.84 (2 H, br
s, NH), 4.98 (1 H, d, J = 7.5 Hz, CH), 6.36–6.46 (2 H, m, Ar), 6.55–
6.62 (2 H, m, Ar), 6.76–6.83 (2 H, m, Ar), 6.91–6.99 (4 H, m, Ar),
7.13–7.26 (8 H, m, Ar).
(8) Ueda, M.; Miyabe, H.; Nishimura, A.; Sugino, H.; Naito, T.
Tetrahedron: Asymmetry 2003, 14, 2857.
(9) Miyabe, H.; Ueda, M.; Naito, T. Chem. Commun. 2000,
2059.
19F NMR (CDCl3): d = –135.4 (2 F, m), –135.8 (2 F, m).
MS (EI): m/z (%) = 201 (16), 200 (100), 122 (19), 95 (9), 77 (6).
(10) Chan, T. H.; Lu, W. Tetrahedron Lett. 1998, 39, 8605.
(11) Chan, T. H.; Lu, W. J. Org. Chem. 2000, 65, 8589.
(12) For a recent example of the successful aqueous allylation of
imines, see: Kobayashi, S.; Busujima, T.; Nagayama, S.
Chem. Commun. 1998, 19.
(13) Hudlicky, M. Chemistry of Organic Fluorine Compounds;
Ellis Horwood: Chichester, 1992.
(14) Welch, J. T. Tetrahedron 1987, 43, 3123.
(15) Organofluorine Chemistry, Principles and Commercial
Applications; Banks, R. E.; Smart, B. E.; Tatlow, J. C., Eds.;
Plenum: New York, 1994.
Anal. Calcd for C26H22F2N2: C, 77.98; H, 5.54; N, 6.70. Found: C,
77.82; H, 5.54; N, 6.86.
N-Benzylpentafluoroaniline (5b)
This compound was isolated by flash column chromatography on
silica gel using hexane as eluent; white solid; mp 148–150 °C.
IR (KBr): 3363, 3036 1518, 1067, 1028, 967 cm–1.
1H NMR (CDCl3): d = 3.95 (1 H, br s, NH), 4.52 (2 H, d, J = 6.6 Hz,
CH), 7.28–7.43 (5 H, m, Ar).
19F NMR (CDCl3): d = –159.0 (2 F, d, 3JF,F = 21.2 Hz), –164.5 (2 F,
(16) Loupy, A.; Petit, A.; Bonnet-Delpon, D. J. Fluorine Chem.
1995, 75, 215.
t, 3JF,F = 21.0 Hz), –171.3 (1 F, m).
(17) Lucet, D.; Le Gall, T.; Mioskowski, C. Angew. Chem. Int.
Ed. 1998, 37, 2581.
(18) Bennani, Y. L.; Hanessian, S. Chem. Rev. 1997, 97, 3161.
(19) Robertson, G. M. Comprehensive Organic Synthesis, Vol. 3;
Pergamon: Oxford, 1991, 579–582.
MS (EI): m/z (%) = 273 (15), 272 (100), 194 (41), 77 (8).
Anal. Calcd for C11H8F5N: C, 57.15; H, 2.95; N, 5.13. Found: C,
57.24; H, 2.78; N, 4.97.
X-ray Data of Compound 4b
(20) (a) Reinhart, K. L.; Harada, K.-i.; Namikoshi, M.; Chen, C.;
Harvis, C. A.; Munro, M. H. G.; Blunt, J. W.; Mulligan, P.
E.; Beasley, V. R.; Dahelm, A. M.; Carmichael, W. W. J.
Am. Chem. Soc. 1988, 110, 8557. (b) de Silva, E. D.;
Williams, D. E.; Anderson, R. J.; Klix, H.; Holmes, C. F. B.;
Allen, T. M. Tetrahedron Lett. 1992, 33, 1561. (c)Fusetani,
N.; Matsunaga, S.; Matsumoto, H.; Takebayshi, Y. J. Am.
Chem. Soc. 1990, 112, 7053. (d) Coleman, J. E.; de Silva, E.
D.; Kong, F.; Andersen, R. J.; Allen, T. M. Tetrahedron
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C26H14F10N2: MW = 544.39, monoclinic; space group: P2/C,
a = 17.879(4), b = 8.9460(18), c = 16.489(3) Å; a = 90.00°,
b = 116.36(3)°, g = 90.00°; V = 2363.1(8)Å3, Z = 4, Dc = 1.530
gcm–1, F(000) = 1096. Radiation: MoKa (l = 0.71073 Å). Crystal
dimension: 0.178 × 0.200 × 0.267 mm.
Intensity data were collected at 293(2) K with a Bruker P4 four-cir-
cle diffractometer with graphite monochromator, and MoKa radia-
tion (l = 0.71073Å). A total of 5442 independent reflections were
measured in range 1.27 < q < 27.50°. The structure was solved by
directed methods and expanded using Fourier techniques. The non-
hydrogen atoms were refined anisotropically, hydrogen atoms were
included but not refined. The final cycle of full matrix least-square
refinement was based on F2. The final R and Rw value were 0.0646
and 0.1106 respectively. All calculations were performed using the
program SHELX-97.
Acknowledgment
The authors thank the National Natural Science Foundation of Chi-
na (NNSFC) (No. 20032010, No. 20372077) and the Excellent
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