Electroreductive acylation of aromatic imines with acylimidazoles

Article abstract of DOI:10.1016/j.tet.2007.11.106

The intermolecular reductive coupling of aromatic imines with acylimidazoles was effected by electroreduction in the presence of chlorotrimethylsilane and gave α-amino-α-aryl ketones. This method was also effective for the synthesis of α-amino-α-aryl esters using methoxycarbonylimidazole as an electrophile.

Full text of DOI:10.1016/j.tet.2007.11.106

Available online at www.sciencedirect.com
Tetrahedron 64 (2008) 1765e1771
www.elsevier.com/locate/tet
Electroreductive acylation of aromatic imines with acylimidazoles
*
Naoki Kise , Shinji Morimoto
Department of Biotechnology, Faculty of Engineering, Tottori University, Koyama, Tottori 680-8552, Japan
Received 15 November 2007; received in revised form 29 November 2007; accepted 29 November 2007
Available online 5 December 2007
Dedicated to the memory of Professor Yoshihiro Matsumura
Abstract
The intermolecular reductive coupling of aromatic imines with acylimidazoles was effected by electroreduction in the presence of chloro-
trimethylsilane and gave a-amino-a-aryl ketones. This method was also effective for the synthesis of a-amino-a-aryl esters using methoxycar-
bonylimidazole as an electrophile.
Ó 2007 Elsevier Ltd. All rights reserved.
1. Introduction
presence of CTMS effected intermolecular reductive C-acyla-
tion of aromatic imines (Scheme 2).2,3 This electroreduction
provides a useful method for the synthesis of a-amino-a-aryl
ketones4,5 and esters.
Recently, we have reported that the electroreduction in the
presence of chlorotrimethylsilane (CTMS) is a useful method
for the reductive intramolecular coupling of aromatic a-, b-,
and g-imino esters (Scheme 1).1 However, this reaction was
limited to intramolecular coupling to give four-, five-, and
six-membered cyclic amines. We therefore attempted intermo-
lecular coupling of aromatic imines with carboxylic acid de-
rivatives more reactive than esters, since this type of
reaction has so far been unknown except for our electroche-
mical method. We wish to report in this paper that the electro-
reduction of aromatic imines with acylimidazoles in the
R
N
Ar
Ar
+ e, CTMS
N
R
+
O
N
HN
An
An
O
An = p-CH3OC6H4 R = alkyl, OCH3
Scheme 2. Electroreductive intermolecular coupling of aromatic imines with
N-acylimidazoles.
2. Results and discussion
Initially, the electroreductive C-acylation of N-benzylidene-
4-methoxybenzenamine (1a) was surveyed with several N-
acylimidazoles and acid anhydrides in the presence of
CTMS and triethylamine (TEA). The results are summarized
in Table 1. The electroreduction was carried out according
to the reported conditions for the electroreductive intramolec-
ular coupling of aromatic iminoesters:1 using Pb cathode and
a divided cell in THF containing Bu4NPF6 as a supporting
electrolyte. C-Acetylated product 2a was obtained in 60%
yield by the reaction with acetylimidazole (run 1). In the ab-
sence of CTMS, 2a was not obtained and simply reduced
amine, N-benzyl-4-methoxybenzenamine, was formed pre-
dominantly in 90% yield (run 2). On the other hand, the ab-
sence of TEA brought about slightly decrease of the yield of
Ar
TMSO OCH3
1) + e, CTMS
2) BzCl/TEA
Ar
R
N
CO2CH3
N
Bz
R
OCH3
N
Ar
TMSO
Ar
1) + e, CTMS
N
2) ClCO2CH3/TEA
n
CO2CH3
n
CO2CH3
n = 1,2
Scheme 1. Electroreductive intramolecular coupling of a-, b-, and g-
iminoesters.
* Corresponding author.
E-mail address: kise@bio.tottori-u.ac.jp (N. Kise).
0040-4020/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2007.11.106

1766
N. Kise, S. Morimoto / Tetrahedron 64 (2008) 1765e1771
Table 1
Electroreduction of 1a with N-acylimidazoles and acid anhydrides
Table 2
Electroreduction of aromatic imines with acetylimidazoles
R
CH3
Ar
Ph
Ph
+ e, CTMS/TEA
Bu4NPF6/THF
Ar
+ e, CTMS/TEA
Bu4NPF6/THF
CH3COIm
+
+
RCOX
N
HN O
An
2f-k
HN O
An
2a-e
N
An
An
1b-f
1a
An:
MeO
Run
1
Ar
Yielda (%) of 2
Run
RCOXa
Yieldb (%) of 2
1
2
3
4
5
6
a
1b
1c
1d
1e
1f
p-MeOC6H4
o-MeOC6H4
3,4-(MeO)2C6H3
p-FC6H4
1-Naphthyl
p-NCC6H4
2f (50)
2g (37)
2h (60)
2i (64)
2j (72)
2k (44)
1
CH3COIm
CH3COIm
CH3COIm
CH3COIm
CH3COIm
(CH3CO)2O
C2H5COIm
(C2H5CO)2O
n-C3H7COIm
2a (60)
2c
3e
4f
5g
6
2a (0) (90)d
2a (53)
2a (58)
2a (55)
1g
2a (25) (60)d
2b (73)
2b (58)
2c (82)
Isolated yields.
7
8
a-aryl ketones 2ler possessing an ester group were obtained
chemoselectively.
9
10
11
12
13
14
a
(n-C3H7CO)2O
i-C3H7COIm
2c (60)
2d (76)
2d (55)
2e (66)
The electroreduction of 1aef,h with methoxycarbonyl-
imidazole gave the corresponding C-methoxycarbonylated
products 3. The results are exhibited in Table 4. By this
method, a-amino-a-aryl methyl esters 3aef,h were obtained
in moderate-to-good yields. Recently, Nishiguchi and co-
workers have reported that the electroreduction of aromatic
imines with methoxycarbonylimidazole using an undivided
cell equipped with Zn electrodes gave geminal C-dimethoxy-
carbonylated products, aryl aminomalonic dimethyl esters.6
On the contrary, the C-monomethoxycarbonylated products
3, N-(p-methoxyphenyl)-2-arylglycine methyl esters, were ob-
tained by our method.
(i-C3H7CO)2O
n-C7H15COIm
(n-C7H15CO)2O
2e (52)
Five equivalents.
Isolated yields.
In the absence of CTMS.
b
c
d
e
f
Yield of simply reduced amine.
In the absence of TEA.
Using Bu4NClO4 in place of Bu4NPF6.
Using Et4NOTs/DMF in place of Bu4NPF6/THF.
g
2a (run 3). These results show that in the intermolecular elec-
troreductive coupling of 1a also the presence of CTMS was
essential, while the presence of triethylamine was not neces-
sarily essential. The use of Bu4NClO4 as a supporting electro-
lyte in place of Bu4NPF6 provided the result comparable to run
1 (run 4). When the electroreduction was carried out in DMF
containing Et4NOTs according to the preliminary report,3 the
yield of 2a was somewhat less than that in run 1 (run 5). Al-
though the same product 2a was obtained by the reaction of 1a
with acetic anhydride (run 6), the yield of 2a (25%) was much
lower than in run 1 and simply reduced amine was obtained as
a major product (60% yield). As shown in Table 1, acylimida-
zoles are generally better acylating agents than acid anhy-
drides and gave the corresponding C-acylated products 2 in
moderate-to-good yields.
Next, several N-arylmethylidene-4-methoxybenzenamines
1bef were subjected to the reductive C-acetylation with acetyl-
imidazole (Table 2). para and ortho Substitutions of methoxy
group and para substitution of cyano group decreased the yields
of a-amino-a-aryl ketones 2f, 2g, and 2k (runs 1, 2, and 6),
whereas 3,4-dimethoxy and para-fluoro substitutions did not in-
hibit the reductive acylation (runs 3 and 4). 1-Naphthyl imine 1f
gave the corresponding a-amino ketone 2j in 72% yield (run 5).
Esters are completely inert under the present conditions. In
fact, the electroreduction of 1a with methyl acetate in the pres-
ence of CTMSeTEA afforded no C-acetylated product 2a. In
accord with the results, the electroreduction of 1aef with acyl-
imidazoles derived from succinic acid and glutaric acid mono-
methyl esters was attempted (Table 3). Expectedly, a-amino-
Removal of N-p-methoxyphenyl (An) group in the acylated
products 2 and 3 was readily achieved by oxidation with CAN
after formylation. Several examples are shown in Scheme 3.
Therefore, this method provides a new synthetic route to
a-amino-a-aryl ketones and 2-arylglycine methyl esters.
The reaction mechanism of the electroreductive intermole-
cular coupling can be speculated in Scheme 4, similar to the
previously reported intramolecular coupling of iminoesters.1
Table 3
Electroreduction of aromatic imines with acylimidazoles possesing a methoxy-
carbonyl group
+ e
Ar
CTMS/TEA
CH3OCO(CH2)nCOIm
n = 2, 3
+
N
Bu4NPF6/THF
An
1a-f
(CH2)nCOOCH3
Ar
HN O
An
2l-r
Run
1
Ar
n
Yielda (%) of 2
1
2
3
4
5
6
7
a
1a
Ph
2
2
2
2
2
2
3
2l (55)
2m (42)
2n (62)
2o (47)
2p (50)
2q (73)
2r (47)
1b
1c
1d
1e
1f
p-MeOC6H4
o-MeOC6H4
3,4-(MeO)2C6H3
p-FC6H4
1-Naphthyl
Ph
1a
Isolated yields.

N. Kise, S. Morimoto / Tetrahedron 64 (2008) 1765e1771
1767
Table 4
Electroreduction of aromatic imines with methoxycarbonylimidazole
4.2. Starting materials
OCH3
Ar
Aromatic imines were synthesized from the corresponding
aromatic aldehydes and p-anisidine by refluxing in benzene
and purified by recrystallization from ethanol. Acetylimida-
zole is commercially available. The other acylimidazoles
were prepared from the corresponding acid chlorides and
imidazole (2 equiv) by stirring in THF.
+ e, CTMS/TEA
Bu4NPF6/THF
Ar
CH3OCOIm
+
HN O
An
N
An
1a-f,h
3a-f,h
Run
1
Ar
Ph
Yielda (%) of 3
1
2
3
4
5
6
7
a
1a
1b
1c
1d
1e
1f
3a (62)
3b (55)
3c (56)
3d (60)
3e (65)
3f (50)
3h (40)
p-MeOC6H4
o-MeOC6H4
3,4-(MeO)2C6H3
p-FC6H4
1-Naphthyl
2-Furyl
4.3. Typical procedure for electroreduction (Table 1, run 1)
A 0.3 M solution of Bu4NPF6 in THF (15 mL) was placed
in the cathodic chamber of a divided cell (40-mL beaker, 3-cm
diameter, 6-cm height) equipped with a lead cathode (5ꢀ
5 cm2), a platinum anode (2ꢀ1 cm2), and a ceramic cylindrical
diaphragm (1.5-cm diameter). A 0.3 M solution of Bu4NPF6 in
DMF (4 mL) was placed in the anodic chamber (inside
the diaphragm). N-Benzylidene-4-methoxybenzenamine (1a)
(211 mg, 1 mmol), acetylimidazole (550 mg, 5 mmol), CTMS
(0.64 mL, 5 mmol), and triethylamine (0.70 mL, 5 mmol)
were added to the cathodic chamber. After 300 C of electricity
was passed at a constant current of 100 mA at room tempera-
ture, the catholyte was evaporated in vacuo. The residue was
diluted with Et2O (30 mL) and insoluble Bu4NPF6 was filtered
off. The filtrate was evaporated in vacuo. The crude mixture
was purified by column chromatography on silica gel (hex-
anes/ethyl acetate¼5/1) to give 2a in 60% yield. The acylated
products were identified by spectroscopic and elemental ana-
lyses as follows.
1h
Isolated yields.
R
Ar
R
Ar
HCONH
1) HCOOH, Ac2O
2) CAN
HN
An
O
O
2a Ar = Ph, R = CH3
4a 54
4d 60
5a 70
5e 68
2d Ar = Ph, R = i-C3H7
3a Ar = Ph, R = OCH3
3e Ar = p-FC6H4, R = OCH3
Scheme 3. Formylation and oxidation with CAN of acylated products 2 and 3.
Two-electron transfer to imine (1a)eCTMS complex generates
the anion A. Nucleophilic attack of the anion A to the carbonyl
group of acetylimidazole forms O-anion B, which immediately
turns to C by elimination of imidazole anion. The product 2a is
obtained by N-desilylation of C during workup.
CH3
Im
O
Ph
Ph
Cl
4.3.1. 1-(4-Methoxyphenylamino)-1-phenylpropan-2-one (2a)
White solid. Mp 126e127 ꢁC. Rf 0.35 (hexanes/ethyl
acetate¼2/1). IR (KBr) 3381, 1711, 1514, 816, 766,
Ph
+2e
CH3COIm
N
N
An
An
TMS
TMS
TMSNAn
A
B
1a-CTMS
1
706 cmꢂ1. H NMR (CDCl3) d 2.12 (s, 3H), 3.69 (s, 3H),
4.94 (s, 1H), 5.15 (br s, 1H), 6.48e6.52 (m, 2H), 6.67e6.71
(m, 2H), 7.29e7.34 (m, 1H), 7.35e7.40 (m, 2H), 7.43e7.47 (m,
2H). 13C NMR (CDCl3) d 26.7 (q), 55.6 (q), 69.0 (d), 114.4 (d),
114.8 (d), 127.8 (d), 128.3 (d), 129.2 (d), 138.3 (s), 140.3 (s),
152.1 (s), 204.3 (s). Anal. Calcd for C16H17NO2: C, 75.27%;
H, 6.71%; N, 5.49%. Found: C, 75.35%; H, 6.68%; N, 5.51%.
CH3
CH3
Ph
TMSNAn
Ph
-Im
workup
HNAn
O
O
2a
C
Scheme 4. Reaction mechanism.
3. Conclusion
4.3.2. 1-(4-Methoxyphenylamino)-1-phenylbutan-2-one (2b)
Pale yellow paste. Rf 0.4 (hexanes/ethyl acetate¼5/1). IR
1
The electroreduction of aromatic imines with acylimid-
azoles in the presence of CTMS and TEA produces reduc-
tively C-acylated products of imines. The presence of CTMS
in the catholyte is essential to promote the electroreductive
coupling. a-Amino-a-aryl ketones and 2-arylglycine methyl
esters were synthesized conveniently by this method.
(neat) 3377, 1717, 1618, 1514, 818, 770, 758, 706 cmꢂ1. H
NMR (CDCl3) d 0.98 (t, 3H, J¼7.3 Hz), 2.37e2.51 (m, 2H),
3.68 (s, 3H), 4.94 (s, 1H), 5.17 (br s, 1H), 6.48e6.52 (m,
2H), 6.66e6.70 (m, 2H), 7.27e7.31 (m, 1H), 7.34e7.38 (m,
2H), 7.42e7.45 (m, 2H). 13C NMR (CDCl3) d 7.6 (q), 32.2
(t), 55.3 (q), 68.0 (d), 114.3 (d), 114.5 (d), 127.6 (d), 128.0
(d), 128.9 (d), 138.4 (s), 140.2 (s), 151.9 (s), 207.0 (s). Anal.
Calcd for C17H19NO2: C, 75.81%; H, 7.11%; N, 5.20%.
Found: C, 75.95%; H, 7.04%; N, 5.30%.
4. Experimental section
4.1. General
4.3.3. 1-(4-Methoxyphenylamino)-1-phenylpentan-2-one (2c)
Pale yellow paste. Rf 0.5 (hexanes/ethyl acetate¼5/1). IR
Column chromatography was performed on silica gel 60.
THF was freshly distilled from sodium benzophenone ketyl.
CTMS and TEA were distilled from CaH2.
(neat) 3377, 1717, 1618, 1514, 818, 758, 704 cmꢂ1 1H
.
NMR (CDCl3) d 0.77 (t, 3H, J¼7.3 Hz), 1.42e1.62 (m, 2H),

1768
N. Kise, S. Morimoto / Tetrahedron 64 (2008) 1765e1771
2.32e2.46 (m, 2H), 3.68 (s, 3H), 4.93 (s, 1H), 5.29 (br s, 1H),
6.48e6.53 (m, 2H), 6.66e6.71 (m, 2H), 7.27e7.32 (m, 1H),
7.33e7.38 (m, 2H), 7.41e7.45 (m, 2H). 13C NMR (CDCl3)
d 13.2 (q), 17.0 (t), 40.8 (t), 55.3 (q), 68.3 (d), 114.4 (d),
114.6 (d), 127.7 (d), 128.0 (d), 128.8 (d), 138.1 (s), 140.1 (s),
151.9 (s), 206.5 (s). Anal. Calcd for C18H21NO2: C, 76.29%;
H, 7.47%; N, 4.94%. Found: C, 76.44%; H, 7.35%; N, 4.84%.
(s). Anal. Calcd for C17H19NO3: C, 71.56%; H, 6.71%; N,
4.91%. Found: C, 71.55%; H, 6.68%; N, 4.87%.
4.3.8. 1-(3,4-Dimethoxyphenyl)-1-(4-methoxyphenylamino)-
propan-2-one (2h)
Pale yellow paste. Rf 0.3 (hexanes/ethyl acetate¼2/1). IR
1
(neat) 3369, 1719, 1593, 1512, 822, 766, 735, 702 cmꢂ1. H
NMR (CDCl3) d 2.12 (s, 3H), 3.69 (s, 3H), 3.85 (s, 3H),
3.87 (s, 3H), 4.86 (s, 1H), 6.49e6.54 (m, 2H), 6.67e6.72 (m,
2H), 6.85e6.89 (m, 2H), 7.03e7.06 (m, 1H). 13C NMR
(CDCl3) d 26.2 (q), 55.2 (q), 55.5 (q), 68.2 (d), 109.7 (d),
111.1 (d), 114.2 (d), 114.4 (d), 120.2 (d), 130.3 (s), 140.1 (s),
148.7 (s), 149.3 (s), 151.8 (s), 204.4 (s). Anal. Calcd for
C18H21NO4: C, 68.55%; H, 6.71%; N, 4.44%. Found: C,
68.65%; H, 6.77%; N, 4.40%.
4.3.4. 1-(4-Methoxyphenylamino)-4-methyl-1-phenylpentan-
2-one (2d)
Pale yellow paste. Rf 0.35 (hexanes/ethyl acetate¼5/1). IR
(neat) 3395, 1715, 1514, 820, 766, 737, 718, 700 cmꢂ1. H
1
NMR (CDCl3) d 0.79 (d, 3H, J¼6.9 Hz), 1.14 (d, 3H, J¼
6.9 Hz), 2.77e2.86 (m, 1H), 3.68 (s, 3H), 5.07 (s, 1H), 5.19
(br s, 1H), 6.50e6.54 (m, 2H), 6.67e6.71 (m, 2H), 7.26e
7.31 (m, 1H), 7.33e7.37 (m, 2H), 7.41e7.44 (m, 2H). 13C
NMR (CDCl3) d 18.2 (q), 19.3 (q), 36.9 (q), 55.5 (q), 66.9
(d), 114.4 (d), 114.7 (d), 127.9 (d), 128.1 (d), 128.9 (d), 138.0
(s), 140.2 (s), 152.0 (s), 210.3 (s). Anal. Calcd for C18H21NO2:
C, 76.29%; H, 7.47%; N, 4.94%. Found: C, 76.40%; H,
7.51%; N, 4.86%.
4.3.9. 1-(4-Fluorophenyl)-1-(4-methoxyphenylamino)-
propan-2-one (2i)
1
Pale yellow paste. Rf 0.25 (hexanes/ethyl acetate¼5/1). H
NMR (CDCl3) d 2.12 (s, 3H), 3.69 (s, 3H), 4.92 (s, 1H), 6.46e
6.50 (m, 2H), 6.67e6.71 (m, 2H), 7.04e7.10 (m, 2H), 7.40e
7.45 (m, 2H). 13C NMR (CDCl3) d 26.4 (q), 55.4 (q), 67.9 (d),
4.3.5. 1-(4-Methoxyphenylamino)-1-phenylnonan-2-one (2e)
Pale yellow paste. Rf 0.3 (hexanes/ethyl acetate¼10/1). IR
114.3 (d), 114.6 (d), 115.9 (d, JCCF¼21.0 Hz), 129.2 (d, JCCCF
¼
1
(neat) 3385, 1701, 1516, 826, 700 cmꢂ1. H NMR (CDCl3)
7.6 Hz), 133.9 (s, JCCCCF¼2.9 Hz), 133.9 (s), 152.1 (s), 162.4
(s, JCF¼245.1 Hz), 203.9 (s). Anal. Calcd for C16H16NO2: C,
70.31%; H, 5.90%; N, 5.12%. Found: C, 70.36%; H, 5.85%;
N, 5.10%.
d 0.84 (t, 3H, J¼7.3 Hz), 1.06e1.27 (m, 8H), 1.39e1.56 (m,
2H), 2.34e2.47 (m, 2H), 3.66 (s, 3H), 4.93 (s, 1H), 5.19 (br
s, 1H), 6.48e6.52 (m, 2H), 6.66e6.70 (m, 2H), 7.27e7.31 (m,
1H), 7.33e7.38 (m, 2H), 7.41e7.44 (m, 2H). 13C NMR
(CDCl3) d 13.9 (q), 22.4 (t), 23.7 (t), 28.8 (t), 31.5 (t), 39.0 (t),
55.6 (q), 68.4 (d), 114.4 (d), 114.7 (d), 127.8 (d), 128.1 (d),
129.0 (d), 138.3 (s), 140.3 (s), 152.0 (s), 206.7 (s). Anal. Calcd
for C22H29NO2: C, 77.84%; H, 8.61%; N, 4.13%. Found: C,
78.03%; H, 8.70%; N, 4.01%.
4.3.10. 1-(4-Methoxyphenylamino)-1-(naphthalen-1-yl)-
propan-2-one (2j)
Pale yellow paste. Rf 0.35 (hexanes/ethyl acetate¼5/1). IR
(neat) 3265, 1711, 1663, 1607, 1510, 831, 800, 781,
1
737 cmꢂ1. H NMR (CDCl3) d 2.05 (s, 3H), 3.66 (s, 3H),
5.24 (br s, 1H), 5.62 (s, 1H), 6.50e6.55 (m, 2H), 6.64e6.68
(m, 2H), 7.47 (dd, 1H, J¼7.3, 8.3 Hz), 7.52e7.56 (m, 1H),
7.58e7.62 (m, 1H), 7.64 (d, 1H, J¼7.3 Hz), 7.84 (d, 1H,
J¼8.3 Hz), 7.92 (d, 1H, J¼8.3 Hz), 8.32 (d, 1H, J¼8.3 Hz).
13C NMR (CDCl3) d 26.8 (q), 55.5 (q), 66.1 (d), 114.5 (d),
114.7 (d), 122.9 (d), 125.6 (d), 125.9 (d), 126.6 (d), 126.8 (d),
129.0 (d), 129.2 (d), 131.2 (s), 133.9 (s), 134.2 (s), 140.7 (s),
152.1 (s), 204.8 (s). Anal. Calcd for C20H19NO2: C,
78.66%; H, 6.27%; N, 4.59%. Found: C, 78.53%; H, 6.19%;
N, 4.50%.
4.3.6. 1-(4-Methoxyphenyl)-1-(4-methoxyphenylamino)-
propan-2-one (2f)
Pale yellow paste. Rf 0.2 (hexanes/ethyl acetate¼5/1). IR
(neat) 3373, 1713, 1676, 1601, 1512, 824, 737 cmꢂ1. 1H NMR
(CDCl3) d 2.11 (s, 3H), 3.69 (s, 3H), 3.80 (s, 3H), 4.89 (s, 1H),
5.08 (br s, 1H), 6.47e6.52 (m, 2H), 6.67e6.71 (m, 2H), 6.88e
6.92 (m, 2H), 7.32e7.37 (m, 2H). 13C NMR (CDCl3) d 26.4
(q), 55.1 (q), 55.5 (q), 68.0 (d), 114.3 (d), 114.4 (d), 114.6 (d),
128.8 (d), 129.9 (s), 140.2 (s), 151.9 (s), 159.4 (s). Anal. Calcd
for C17H19NO3: C, 71.56%; H, 6.71%; N, 4.91%. Found: C,
71.68%; H, 6.62%; N, 4.97%.
4.3.11. 4-(1-(4-Methoxyphenylamino)-2-oxopropyl)-
benzonitrile (2k)
4.3.7. 1-(2-Methoxyphenyl)-1-(4-methoxyphenylamino)-
propan-2-one (2g)
Pale yellow paste. Rf 0.45 (hexanes/ethyl acetate¼2/1). IR
White solid. Mp 109e110 ꢁC. Rf 0.3 (hexanes/ethyl
acetate¼5/1). IR (KBr) 3402, 1711, 1597, 1516, 1489, 824,
806, 754 cmꢂ1. 1H NMR (CDCl3) d 2.10 (s, 3H), 3.68 (s, 3H),
3.99 (s, 3H), 5.10 (br s, 1H), 5.50 (s, 1H), 6.46e6.51 (m, 2H),
6.65e6.70 (m, 2H), 6.89e6.93 (m, 1H), 6.94e6.98 (m, 1H),
7.23e7.29 (m, 2H). 13C NMR (CDCl3) d 26.4 (q), 55.5 (q),
61.4 (d), 110.7 (d), 114.2 (d), 114.7 (d), 121.3 (d), 126.2 (s),
128.0 (d), 129.2 (d), 140.4 (s), 151.9 (s), 156.9 (s), 204.5
(neat) 3377, 2230, 1721, 1605, 1514, 824, 758 cmꢂ1 1H
.
NMR (CDCl3) d 2.14 (s, 3H), 3.69 (s, 3H), 5.00 (s, 1H),
5.19 (br s, 1H), 6.42e6.46 (m, 2H), 6.67e6.71 (m, 2H),
7.59e7.62 (m, 2H), 7.67e7.70 (m, 2H). 13C NMR (CDCl3)
d 26.6 (q), 55.4 (q), 68.4 (d), 112.0 (s), 114.3 (d), 114.7 (d),
118.2 (s), 128.4 (d), 132.7 (d), 139.3 (s), 143.8 (s), 152.3
(s), 202.4 (s). Anal. Calcd for C17H18N2O2: C, 72.84%; H,
5.75%; N, 9.99%. Found: C, 72.65%; H, 5.84%; N, 10.18%.

N. Kise, S. Morimoto / Tetrahedron 64 (2008) 1765e1771
1769
4.3.12. Methyl 5-(4-methoxyphenylamino)-4-oxo-5-phenyl-
pentanoate (2l)
4.3.16. Methyl 5-(4-fluorophenyl)-5-(4-methoxyphenyl-
amino)-4-oxopentanoate (2p)
Pale yellow paste. Rf 0.25 (hexanes/ethyl acetate¼5/1). IR
Pale yellow paste. Rf 0.37 (hexanes/ethyl acetate¼2/1). IR
1
(neat) 3383, 1732, 1605, 1514, 822, 764, 702 cmꢂ1
.
1H
(neat) 3385, 1736, 1603, 1514, 824 cmꢂ1. H NMR (CDCl3)
NMR (CDCl3) d 2.42e2.50 (m, 1H), 2.56e2.67 (m, 2H),
2.80e2.89 (m, 1H), 3.63 (s, 3H), 3.69 (s, 3H), 5.01 (s, 1H),
5.11 (br s, 1H), 6.49e6.54 (m, 2H), 6.68e6.72 (m, 2H), 7.30e
7.34 (m, 1H), 7.36e7.40 (m, 2H), 7.44e7.48 (m, 2H). 13C
NMR (CDCl3) d 27.6 (t), 33.7 (t), 51.5 (q), 55.4 (q), 68.3
(d), 114.3 (d), 114.5 (d), 127.6 (d), 128.1 (d), 129.0 (d),
138.0 (s), 140.1 (s), 152.0 (s), 172.5 (s), 205.0 (s). Anal. Calcd
for C19H21NO4: C, 69.71%; H, 6.47%; N, 4.28%. Found: C,
69.78%; H, 6.41%; N, 4.22%.
d 2.44e2.52 (m, 1H), 2.55e2.70 (m, 2H), 2.79e2.87 (m, 1H),
3.64 (s, 3H), 3.70 (s, 3H), 5.00 (s, 1H), 5.10 (br s, 1H), 6.47e
6.51 (m, 2H), 6.68e6.72 (m, 2H), 7.05e7.11 (m, 2H), 7.42e
7.47 (m, 2H). 13C NMR (CDCl3) d 27.7 (t), 33.8 (t), 51.7 (q),
55.5 (q), 67.6 (d), 114.5 (d), 114.7 (d), 116.1 (d, JCCF
¼
22.1 Hz), 129.4 (d, JCCCF¼7.7 Hz), 133.9 (s, JCCCCF¼2.9 Hz),
140.0 (s), 152.2 (s), 162.5 (s, JCF¼247.6 Hz), 172.6 (s), 204.9
(s). Anal. Calcd for C19H20FNO4: C, 66.08%; H, 5.84%; N,
4.06%. Found: C, 66.14%; H, 5.80%; N, 3.96%.
4.3.13. Methyl 5-(4-methoxyphenyl)-5-(4-methoxyphenyl-
amino)-4-oxopentanoate (2m)
4.3.17. Methyl 5-(4-methoxyphenylamino)-5-(naphthalen-
1-yl)-4-oxopentanoate (2q)
Pale yellow paste. Rf 0.33 (hexanes/ethyl acetate¼2/1). IR
Pale yellow paste. Rf 0.47 (hexanes/ethyl acetate¼2/1). IR
(neat) 3381, 1732, 1717, 1609, 1514, 824 cmꢂ1 1H NMR
.
(neat) 3387, 1717, 1618, 1597, 1514, 822, 800, 779,
1
(CDCl3) d 2.41e2.50 (m, 1H), 2.56e2.68 (m, 2H), 2.78e
2.87 (m, 1H), 3.64 (s, 3H), 3.70 (s, 3H), 3.80 (s, 3H), 4.95 (s,
1H), 5.06 (br s, 1H), 6.49e6.53 (m, 2H), 6.68e6.72 (m, 2H),
6.89e6.93 (m, 2H), 7.34e7.38 (m, 2H). 13C NMR (CDCl3)
d 27.6 (t), 33.7 (t), 51.6 (q), 55.0 (q), 55.4 (q), 67.6 (d),
114.36 (d), 114.41 (d), 114.6 (d), 128.8 (d), 129.8 (s), 140.2
(s), 152.0 (s), 159.4 (s), 172.6 (s), 205.4 (s). Anal. Calcd for
C20H23NO5: C, 67.21%; H, 6.49%; N, 3.92%. Found: C,
67.43%; H, 6.56%; N, 3.87%.
735 cmꢂ1. H NMR (CDCl3) d 2.35e2.44 (m, 2H), 2.60e
2.67 (m, 1H), 2.81e2.90 (m, 1H), 3.61 (s, 3H), 3.67 (s, 3H),
5.20 (br s, 1H), 5.70 (s, 1H), 6.52e6.55 (m, 2H), 6.65e6.69
(m, 2H), 7.46e7.51 (m, 1H), 7.53e7.57 (m, 1H), 7.58e7.63
(m, 1H), 7.64e7.68 (m, 1H), 7.85 (d, 1H, J¼8.3 Hz), 7.92 (d,
1H, J¼8.3 Hz), 8.32 (d, 1H, J¼8.7 Hz). 13C NMR (CDCl3)
d 27.5 (t), 33.8 (t), 51.4 (q), 55.3 (q), 65.5 (d), 114.4 (d),
114.5 (d), 122.8 (d), 125.5 (d), 125.8 (d), 126.7 (d), 128.9
(d), 129.0 (d), 131.1 (s), 133.7 (s), 134.1 (s), 140.6 (s), 152.0
(s), 172.5 (s), 205.7 (s). Anal. Calcd for C23H23NO4: C,
73.19%; H, 6.14%; N, 3.71%. Found: C, 73.04%; H, 6.09%;
N, 3.65%.
4.3.14. Methyl 5-(2-methoxyphenyl)-5-(4-methoxyphenyl-
amino)-4-oxopentanoate (2n)
Pale yellow paste. Rf 0.33 (hexanes/ethyl acetate¼2/1). IR
(neat) 3393, 1738, 1720, 1618, 1599, 1514, 1489, 822, 758,
4.3.18. Methyl 6-(4-methoxyphenylamino)-5-oxo-6-phenyl-
hexanoate (2r)
1
733 cmꢂ1. H NMR (CDCl3) d 2.43e2.51 (m, 1H), 2.57e
2.66 (m, 2H), 2.81e2.91 (m, 1H), 3.63 (s, 3H), 3.69 (s, 3H),
3.99 (s, 3H), 5.05 (br s, 1H), 5.54 (s, 1H), 6.49e6.53 (m,
2H), 6.67e6.71 (m, 2H), 6.29 (t, 1H, J¼7.3 Hz), 6.97 (d,
1H, J¼8.3 Hz), 7.25e7.30 (m, 2H). 13C NMR (CDCl3)
d 27.5 (t), 33.5 (t), 51.4 (q), 55.28 (q), 55.31 (q), 60.9 (d),
110.7 (d), 114.0 (d), 114.4 (d), 121.0 (d), 126.0 (s), 128.0 (d),
129.1 (q), 140.3 (s), 151.8 (s), 156.7 (s), 172.6 (s), 205.1 (s).
Anal. Calcd for C20H23NO5: C, 67.21%; H, 6.49%; N, 3.92%.
Found: C, 67.35%; H, 6.58%; N, 3.93%.
Pale yellow paste. Rf 0.43 (hexanes/ethyl acetate¼5/1). IR
(neat) 3354, 1734, 1599, 1514, 826, 756, 702 cmꢂ1 1H
.
NMR (CDCl3) d 1.73e1.90 (m, 2H), 2.10e2.26 (m, 2H),
2.42e2.60 (m, 2H), 3.60 (s, 3H), 3.68 (s, 3H), 4.94 (s, 1H),
5.13 (br s, 1H), 6.48e6.52 (m, 2H), 6.67e6.70 (m, 2H), 7.28e
7.32 (m, 1H), 7.34e7.38 (m, 2H), 7.40e7.44 (m, 2H). 13C
NMR (CDCl3) d 18.7 (t), 32.5 (t), 37.8 (t), 51.4 (q), 55.5
(q), 68.4 (d), 114.4 (d), 114.7 (d), 127.7 (d), 128.2 (d), 129.1
(d), 138.0 (s), 140.1 (s), 152.0 (s), 173.2 (s), 205.9 (s). Anal.
Calcd for C20H23NO4: C, 70.36%; H, 6.79%; N, 4.10%.
Found: C, 70.48%; H, 6.83%; N, 3.99%.
4.3.15. Methyl 5-(3,4-dimethoxyphenyl)-5-(4-methoxy-
phenylamino)-4-oxopentanoate (2o)
Pale yellow paste. Rf 0.20 (hexanes/ethyl acetate¼2/1). IR
4.3.19. Methyl 2-(4-methoxyphenylamino)-2-phenylacetate
(3a)
(neat) 3375, 1732, 1593, 1514, 824, 766, 733 cmꢂ1 1H
.
NMR (CDCl3) d 2.41e2.51 (m, 1H), 2.57e2.69 (m, 2H),
2.80e2.88 (m, 1H), 3.64 (s, 3H), 3.70 (s, 3H), 3.86 (s, 3H),
3.88 (s, 3H), 4.93 (s, 1H), 5.06 (br s, 1H), 6.51e6.55 (m,
2H), 6.69e6.72 (m, 2H), 6.87e6.89 (m, 2H), 7.05e7.08 (m,
1H). 13C NMR (CDCl3) d 27.7 (t), 33.6 (t), 51.6 (q), 55.4
(q), 55.7 (q), 68.1 (d), 109.9 (d), 111.3 (d), 114.4 (d), 114.6
(d), 120.4 (d), 130.4 (s), 140.3 (s), 148.9 (s), 149.5 (s),
152.0 (s), 172.6 (s), 205.4 (s). Anal. Calcd for C21H25NO6:
C, 65.10%; H, 6.50%; N, 3.62%. Found: C, 65.23%; H,
6.60%; N, 3.65%.
White solid. Mp 107e108 ꢁC. Rf 0.4 (hexanes/ethyl
acetate¼5/1). IR (KBr) 3418, 1732, 1620, 1597, 1585, 1514,
989, 939, 818, 764, 731, 698 cmꢂ1 1H NMR (CDCl3)
.
d 3.71 (s, 3H), 3.73 (s, 3H), 4.67 (br s, 1H), 5.02 (s, 1H), 6.51e
6.55 (m, 2H), 6.70e6.74 (m, 2H), 7.28e7.39 (m, 3H), 7.46e
7.50 (m, 2H). 13C NMR (CDCl3) d 52.6 (q), 55.5 (q), 61.5 (d),
114.6 (d), 114.7 (d), 127.1 (d), 128.1 (d), 128.7 (d), 137.6 (s),
140.0 (s), 152.3 (s), 172.4 (s). Anal. Calcd for C16H17NO3: C,
70.83%; H, 6.32%; N, 5.16%. Found: C, 70.85%; H, 6.32%;
N, 5.23%.

1770
N. Kise, S. Morimoto / Tetrahedron 64 (2008) 1765e1771
4.3.20. Methyl 2-(4-methoxyphenyl)-2-(4-methoxyphenyl-
amino)acetate (3b)
4.71 (br s, 1H), 5.78 (s, 1H), 6.52e6.56 (m, 2H), 6.69e6.73
(m, 2H), 7.44 (dd, 1H, J¼7.3, 8.3 Hz), 7.52e7.55 (m, 1H),
7.57e7.61 (m, 1H), 7.62e7.64 (m, 1H), 7.83 (d, 1H, J¼
8.3 Hz), 7.89e7.92 (m, 1H), 8.30 (d, 1H, J¼8.3 Hz). 13C
NMR (CDCl3) d 52.5 (q), 55.4 (q), 58.1 (d), 114.4 (d), 114.7
(d), 123.2 (d), 124.9 (d), 125.4 (d), 125.7 (d), 126.5 (d), 128.8
(d), 128.9 (d), 131.1 (s), 133.4 (s), 133.9 (s), 140.3 (s), 152.4
(s), 172.7 (s). Anal. Calcd for C20H19NO3: C, 74.75%; H,
5.96%; N, 4.36%. Found: C, 74.86%; H, 5.76%; N, 4.19%.
White solid. Mp 91e92 ꢁC. Rf 0.3 (hexanes/ethyl acetate¼
5/1). IR (KBr) 3366, 1728, 1612, 1512, 972, 824, 797, 752,
1
704 cmꢂ1. H NMR (CDCl3) d 3.71 (s, 3H), 3.72 (s, 3H),
3.79 (s, 3H), 4.60 (br s, 1H), 4.96 (s, 1H), 6.51e6.55 (m, 2H),
6.70e6.75 (m, 2H), 6.86e6.90 (2H), 7.38e7.41 (m, 2H). 13C
NMR (CDCl3) d 52.5 (q), 55.1 (q), 55.5 (q), 60.8 (d), 114.1
(d), 114.6 (d), 114.7 (d), 128.3 (d), 129.6 (s), 140.1 (s), 152.3
(s), 159.4 (s), 172.7 (s). Anal. Calcd for C17H19NO4: C,
67.76%; H, 6.36%; N, 4.65%. Found: C, 67.58%; H, 6.30%;
N, 4.67%.
4.3.25. Methyl 2-(furan-2-yl)-2-(4-methoxyphenylamino)-
acetate (3h)
White solid. Mp 80e81 ꢁC. Rf 0.4 (hexanes/ethyl acetate¼
5/1). 1H NMR (CDCl3) d 3.73 (s, 3H), 3.77 (s, 3H), 4.50 (br s,
1H), 5.15 (s, 1H), 6.33e6.37 (m, 1H), 6.60e6.65 (m, 2H),
6.74e6.79 (m, 2H), 6.90e6.95 (m, 1H), 7.38e7.41 (m, 1H).
13C NMR (CDCl3) d 52.7 (q), 55.4 (q), 56.0 (d), 108.0 (d),
110.5 (d), 114.7 (d), 115.2 (d), 139.7 (s), 142.6 (d), 150.1 (s),
152.9 (s), 170.6 (s). Anal. Calcd for C14H15NO4: C, 64.36%;
H, 5.79%; N, 5.36%. Found: C, 64.37%; H, 5.76%; N, 5.33%.
4.3.21. Methyl 2-(2-methoxyphenyl)-2-(4-methoxyphenyl-
amino)acetate (3c)
White solid. Mp 123e124 ꢁC. Rf 0.25 (hexanes/ethyl
acetate¼5/1). IR (KBr) 3387, 1736, 1601, 1518, 1497, 974,
827, 773, 756 cmꢂ1. 1H NMR (CDCl3) d 3.70 (s, 3H), 3.71 (s,
3H), 3.91 (s, 3H), 4.61 (br s, 1H), 5.44 (s, 3H), 6.58e6.63 (m,
2H), 6.70e6.74 (m, 2H), 6.91e6.95 (m, 2H), 7.25e7.30 (m,
1H), 7.33e7.35 (m, 1H). 13C NMR (CDCl3) d 52.2 (q), 55.3
(q), 55.5 (q and t), 110.9 (d), 114.5 (d), 114.8 (d), 120.8 (d),
126.3 (s), 127.9 (d), 129.2 (d), 140.4 (s), 152.3 (s), 156.9
(s), 172.8 (s). Anal. Calcd for C17H19NO4: C, 67.76%; H,
6.36%; N, 4.65%. Found: C, 67.79%; H, 6.36%; N, 4.61%.
4.4. Typical procedure of formylation and oxidation with
CAN of 2 and 3
A solution of 3a (100 mg, 0.37 mmol), acetic anhydride
(1 mL), and formic acid (3 mL) was refluxed for 2 h. The so-
lution was diluted with 2 M NaHCO3 (50 mL) and extracted
with ethyl acetate. After the solvent was removed, the crude
formate was dissolved in CH3CN (5 mL). To the solution
was added slowly an aqueous solution (3 mL) of CAN
(405 mg, 0.74 mmol) at 5 ꢁC for 1 h. The mixture was diluted
with H2O (30 mL) and extracted with ethyl acetate. After the
solvent was removed, the crude mixture was purified by col-
umn chromatography on basic alumina (hexanes/ethyl
acetate¼2/1) to give 5a in 70% yield.
4.3.22. Methyl 2-(3,4-dimethoxyphenyl)-2-(4-methoxy-
phenylamino)acetate (3d)
Pale yellow paste. Rf 0.4 (hexanes/ethyl acetate¼2/1). IR
(neat) 3369, 1740, 1593, 1514, 824, 764 cmꢂ1 1H NMR
.
(CDCl3) d 3.71 (s, 3H), 3.73 (s, 3H), 3.87 (s, 3H), 3.88 (s,
3H), 4.60 (br s, 1H), 4.94 (s, 1H), 6.52e6.57 (m, 2H), 6.70e
6.75 (m, 2H), 6.84 (d, 1H, J¼8.3 Hz), 6.99 (d, 1H, J¼1.8 Hz),
7.03 (dd, 1H, J¼1.8, 8.3 Hz). 13C NMR (CDCl3) d 52.3 (q),
55.2 (q), 55.5 (q), 61.0 (d), 109.8 (d), 110.9 (d), 114.5 (d),
119.4 (d), 129.9 (s), 140.0 (s), 148.6 (s), 148.9 (s), 152.2 (s),
172.4 (s). Anal. Calcd for C18H21NO5: C, 65.24%; H,
6.39%; N, 4.23%. Found: C, 65.40%; H, 6.31%; N, 4.10%.
4.4.1. N-(2-Oxo-1-phenylpropyl)formamide (4a)
1
4.3.23. Methyl 2-(4-fluorophenyl)-2-(4-methoxyphenyl-
amino)acetate (3e)
Colorless paste. Rf 0.25 (hexanes/ethyl acetate¼1/1). H
NMR (CDCl3) d 2.12 (s, 3H), 5.62 (d, 1H, J¼6.9 Hz), 7.05
(br s, 1H), 7.31e7.41 (m, 5H), 8.21 (br s, 1H). 13C NMR
(CDCl3) d 26.9 (q), 62.2 (d), 127.8 (d), 128.7 (d), 129.2 (d),
135.8 (s), 160.3 (d), 202.8 (s). Anal. Calcd for C10H11NO2:
C, 67.78%; H, 6.26%; N, 7.90%. Found: C, 67.84%; H,
6.31%; N, 7.69%.
White solid. Mp 99e100 ꢁC. Rf 0.35 (hexanes/ethyl
acetate¼5/1). IR (KBr) 3418, 1734, 1601, 1516, 837, 818,
806, 773 cmꢂ1. 1H NMR (CDCl3) d 3.71 (s, 3H), 3.73 (s, 3H),
4.67 (br s, 1H), 4.99 (s, 1H), 6.49e6.53 (m, 2H), 6.70e6.74
(m, 2H), 7.01e7.06 (m, 2H), 7.44e7.49 (m, 2H). 13C NMR
(CDCl3) d 52.7 (q), 55.5 (q), 60.8 (d), 114.7 (d), 115.6 (d,
JCCF¼21.9 Hz), 128.8 (d, JCCCF¼7.6 Hz), 133.4 (s, JCCCCF
¼
2.9 Hz), 139.8 (s), 152.5 (s), 162.4 (s, JCF¼245.1 Hz), 172.3
(s). Anal. Calcd for C16H16FNO3: C, 66.43%; H, 5.57%; N,
4.84%. Found: C, 66.42%; H, 5.53%; N, 4.80%.
4.4.2. N-(3-Methyl-2-oxo-1-phenylbutyl)formamide (4d)
1
Colorless paste. Rf 0.45 (hexanes/ethyl acetate¼1/1). H
NMR (CDCl3) d 0.89 (d, 3H, J¼6.9 Hz), 1.16 (d, 3H,
J¼6.9 Hz), 2.66e2.75 (m, 1H), 5.77 (d, 1H, J¼6.9 Hz), 7.09
(br s, 1H), 7.29e7.39 (m, 5H), 8.19 (br s, 1H). 13C NMR
(CDCl3) d 17.8 (q), 19.1 (q), 37.6 (d), 59.9 (d), 128.1 (d),
128.6 (d), 129.1 (d), 135.9 (s), 160.1 (d), 209.3 (s). Anal.
Calcd for C12H15NO2: C, 70.22%; H, 7.37%; N, 6.82%.
Found: C, 70.28%; H, 7.33%; N, 6.67%.
4.3.24. Methyl 2-(4-methoxyphenylamino)-2-(naphthalen-
1-yl)acetate (3f)
Pale yellow paste. Rf 0.35 (hexanes/ethyl acetate¼5/1). IR
(neat) 3398, 1732, 1618, 1597, 1514, 822, 799, 777,
1
735 cmꢂ1. H NMR (CDCl3) d 3.69 (s, 3H), 3.71 (s, 3H),

N. Kise, S. Morimoto / Tetrahedron 64 (2008) 1765e1771
1771
4.4.3. Methyl 2-formamido-2-phenylacetate (5a)
References and notes
1
Colorless paste. Rf 0.25 (hexanes/ethyl acetate¼1/1). H
1. (a) Kise, N.; Ozaki, H.; Moriyama, N.; Kitagishi, Y.; Ueda, N. J. Am. Chem.
Soc. 2003, 125, 11591e11596; (b) Kise, N.; Ohya, K.; Arimoto, K.;
Yamashita, Y.; Hirano, Y.; Ono, T.; Ueda, N. J. Org. Chem. 2004, 69,
7710e7719; (c) Kise, N.; Hirano, Y.; Tanaka, Y. Org. Lett. 2006, 8,
1323e1325.
NMR (CDCl3) d 3.73 (s, 3H), 5.66 (d, 1H, J¼7.5 Hz), 6.93 (br
s, 1H), 7.31e7.38 (m, 5H), 8.21 (br s, 1H). 13C NMR (CDCl3)
d 52.8 (q), 55.0 (d), 127.1 (d), 128.6 (d), 128.9 (d), 136.0 (s),
160.3 (d), 170.9 (s). Anal. Calcd for C10H11NO3: C, 62.17%;
H, 5.74%; N, 7.25%. Found: C, 62.25%; H, 5.73%; N, 7.19%.
2. Electroreductive acylation of aromatic ketones with acylimidazoles. See:
Kise, N.; Agui, S.; Morimoto, S.; Ueda, N. J. Org. Chem. 2005, 70,
9407e9410.
4.4.4. Methyl 2-(4-fluorophenyl)-2-formamidoacetate (5e)
Colorless paste. Rf 0.2 (hexanes/ethyl acetate¼1/1). 1H
NMR (CDCl3) d 3.76 (s, 3H), 5.64 (d, 1H, J¼7.2 Hz), 6.73 (br
s, 1H), 7.03e7.08 (m, 2H), 7.33e7.37 (m, 2H), 8.24 (br s,
3. Preliminary communication. See: Shono, T.; Kise, N.; Kunimi, N.;
Nomura, R. Chem. Lett. 1991, 2191e2194.
4. a-Amino ketones are useful precursors for the diastereoselective synthesis
of b-amino alcohols. See: Yin, J.; Huffman, M. A.; Conrad, K. M.;
Armstrong, J. D., III. J. Org. Chem. 2006, 71, 840e843.
1H). 13C NMR (CDCl3) d 53.0 (q), 54.3 (d), 115.9 (d, JCCF
¼
5. The synthesis of a-amino ketones by the addition of acylzirconocene chlo-
rides to imines has been reported. See: Kakuuchi, A.; Taguchi, T.;
Hanzawa, Y. Eur. J. Org. Chem. 2003, 116e122.
22.1 Hz), 128.9 (d, JCCCF¼8.6 Hz), 131.9 (s, JCCCCF¼3.8 Hz),
160.2 (s), 162.7 (s, JCF¼247.6 Hz), 170.8 (s). Anal. Calcd for
C10H10FNO3: C, 56.87%; H, 4.77%; N, 6.63%. Found: C,
56.75%; H, 4.83%; N, 6.50%.
6. Nishiguchi, I.; Sunderrao, K. P.; Yamamoto, U.; Yamamoto, Y.; Uchida, T.;
Maekawa, H. Electrochemistry 2006, 680e684.