Iridium-Catalyzed coupling reaction of primary alcohols with 2-alkynes leading to hydroacylation products

Article abstract of DOI:10.1002/chem.200902646

A novel iridium-catalyzed intermolecular coupling reaction of primary alcohols or aldehydes with 2-alkynes was successfully achieved with high regioselectivity to give hydroacylation products such as α,β- unsaturated ketones in good yields. The mechanistic investigation of the reaction strongly indicated that the coupling proceeds through the initial formation of homoallylic alcohols followed by dehydrogenation to β,γ-unsatutated ketones and then isomerisation, which leads to the hydroacylation products.

Full text of DOI:10.1002/chem.200902646

FULL PAPER
DOI: 10.1002/chem.200902646
Iridium-Catalyzed Coupling Reaction of Primary Alcohols with 2-Alkynes
Leading to Hydroacylation Products
Shintaro Hatanaka, Yasushi Obora,* and Yasutaka Ishii*[a]
Abstract: A novel iridium-catalyzed intermolecular coupling reaction of primary
alcohols or aldehydes with 2-alkynes was successfully achieved with high regiose-
lectivity to give hydroacylation products such as a,b-unsaturated ketones in good
Keywords: alcohols · aldehydes ·
yields. The mechanistic investigation of the reaction strongly indicated that the
alkynes · hydroacylation · iridium
coupling proceeds through the initial formation of homoallylic alcohols followed
by dehydrogenation to b,g-unsatutated ketones and then isomerisation, which
leads to the hydroacylation products.
Introduction
mation of 2-alkynes with primary alcohols to afford hydro-
AHCTUNGTREGaNNUN cylation products such as a,b-unsaturated ketones. In addi-
Transition-metal-catalyzed hydroacylation of alkynes with
aldehydes is a useful methodology for introducing carbonyl
functionalities into unsaturated compounds.[1] To date, the
hydroacylation of alkynes has been mainly limited to intra-
molecular reactions[2] in contrast with intermolecular alkyne
hydroacylation, which is mostly found in the reactions with
substrates that have directing groups that accelerate the hy-
droacylation process.[3] However, the intermolecular hydroa-
cylation of alkynes with simple aldehydes without directing
groups has been far less explored.[4]
tion, we found that the hydroacylation products were also
obtained from aldehydes and 2-butyne.[8] Quite recently,
Krische and co-workers reported the relevant Ru-catalyzed
hydroacylation reaction of alcohols or aldehydes with al-
kynes.[9] This work prompted us to report our independent
findings on an Ir-catalyzed reaction of primary alcohols or
aldehydes with 2-alkynes (Scheme 1).
It is well known that Ir complexes serve as efficient hy-
drogen-transfer catalysts from alcohols to aldehydes, which
can be utilized in the a-alkylation of ketones and activated
methylene compounds with alcohols, as well as the b-alkyla-
tion of alcohols (the Guerbet reaction).[5,6]
Scheme 1. Ir-catalyzed hydroacylation of 2-alkynes with primary alcohols
or aldehydes.
Recently, we reported an Ir-catalyzed coupling reaction of
1-aryl-1-propynes with primary alcohols leading to secon-
dary homoallylic alcohols through the formation of hydrido-
Results and Discussion
ACHTUNGTRENNUNG
(p-allyl)iridium as a possible key intermediate.[7] During the
course of this study, we found a novel Ir-catalyzed transfor-
The reaction of benzyl alcohol (1a) with 2-butyne (2a) was
chosen as a model reaction and was carried out under vari-
ous conditions (Table 1). For instance, 1a (0.5 mmol) was al-
lowed to react with 2a (1 mmol) in the presence of [{IrCl-
[a] S. Hatanaka, Dr. Y. Obora, Prof. Dr. Y. Ishii
Department of Chemistry and Material Engineering
Faculty of Chemistry, Materials and Bioengineering
High Technology Research Center, and ORDIST
Kansai University, Suita, Osaka 564-8680 (Japan)
Fax : (+81)6-6339-4026
AHCTUNGTRENNUNG
A
ACHTUNGTRENNUNG
20 mol%) in toluene (1 mL) at 1208C for 15 h to give 2-
methyl-1-phenyl-2-buten-1-one (3a) in 92% isolated yield
(Table 1, entry 1). The highest yield of 3a was obtained
when 2 equivalents of 2a was reacted with 1a, whereas the
equimolar reaction of 1a and 2a resulted in a considerable
E-mail: obora@kansai-u.ac.jp
ishii@ipcku.kansai-u.ac.jp
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/chem.200902646.
Chem. Eur. J. 2010, 16, 1883 – 1888
ꢀ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1883

Table 1. Ir-catalyzed coupling of 1a with 2a under various reaction con-
Table 2. Ir-catalyzed coupling of primary alcohols 1 with 2-alkynes 2
ditions.[a]
leading to hydroacylation products.[a]
Entry Alcohol 1
Alkyne 2
Yield [%][b]
Entry Ir-catalyst
(mol%)
Ligand
(mol%)
Yield [%][b]
G
G
3a (E:Z)
(n-oct)3 (20) 94 [92] (66:34)
(n-oct)3 (20) 32 (91:9)
(n-oct)3 (20) 7 (63:37)
(nBu)3 (20) 49 (57:43)
4a
5a
1
N
G
P
P
P
P
N
–
trace
–
11
9
trace
–
9
–
2[c]
3[d]
4
trace
40
21
15
trace
–
1[c]
2[c]
3
R=Me (1b)
R=MeO (1c)
R=Cl (1d)
2a
2a
2a
2a
83 (50:50) (3b)
76 (54:46) (3c)
85 (60:40) (3d)
67 (56:44) (3e)
G
5
N
U
PPh3 (20)
PCy3 (20)
dppp (10)
none
6 (51:49)
trace
26 (51:49)
–
6
N
U
4
R=CF3 (1e)
7
N
U
8
N
U
–
9
10
11
N
E
P
P
P
G
–
10
–
7
30
–
G
5[d]
6[d]
X=O (1 f)
X=S (1g)
2a
2a
71 (81:19) (3 f)
73 (78:22) (3g)
[a] Conditions: Alcohol 1a (0.5 mmol) was allowed to react with 2a
(1 mmol) in the presence of the Ir-catalyst (5 mol%) combined with the
phosphine ligand (20 mol%) in toluene (1 mL) at 1208C for 15 h. [b] GC
yields based on 1a were used. The numbers in parentheses show the E/Z
ratio estimated by GC. The number in square brackets shows the isolated
yield. [c] Alkyne 2a (0.5 mmol) was used. [d] The reaction was performed
at 1008C.
7[c]
2a
2a
8[d,e]
decrease of the yield of 3a (Table 1, entry 1 vs. entry 2). As
for the reaction temperature, the best result was obtained at
1208C, but the reaction at 1008C led to homoallylic alcohol
4a as a major product (40%) along with a small amount of
3a (7%) and b,g-unsaturated ketone 5a (11%; Table 1,
entry 3). Among the phosphine ligands examined, the best
9[d,e] R=Ph (1a)
2b
2b
2b
2b
70 (16:84) (3j)
34 (98:2) (3k)
43 (86:14) (3l) 22 (4l)
45 (82:18) (3m) 10 (4m)
–
10[f,g] R=Me (1j)
12 (4k)
11[f,g] R=n-C3H7 (1k)
12[f,g] R=n-C7H15 (1l)
performance of [{IrCl
nation of tri(n-octyl)phosphine as a ligand. Other selected
phosphine ligands such as P(nBu)3, PPh3, PCy3, and dppp
ACHTUNGTNER(NUNG cod)}2] was accomplished by a combi-
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
[a] Conditions: Alcohol 1a (0.5 mmol) was allowed to react with 2a
(1 mmol) in the presence of [{IrCl(cod)}2] (0.025 mmol) combined with P-
(n-oct)3 (0.1 mmol) in toluene (1 mL) at 1208C for 15 h. [b] Isolated
yields. The numbers in parentheses show the E/Z ratio estimated by
1H NMR spectroscopy. [c] Alkyne (2 mmol) was used. [d] [{IrCl
(cod)}2]
(0.05 mmol) and P(n-oct)3 (0.2 mmol) were used. [e] Alkyne (5 mmol)
was used. [f] Alkyne (2.5 mmol) was used. [g] [{Ir(cod)(OH)}2]
(0.05 mmol) and P(n-oct)3 (0.3 mmol) were used.
AHCTUNGTRENNUNG
(1,3-bis(diphenylphosphino)propane) were found to be less
efficient (Table 1, entries 4–7). No reaction was induced in
the absence of a phosphine ligand (Table 1, entry 8). As for
AHCTUNGTRENNUNG
ACHTUNGTRENNUNG
the selection of an iridium complex, [{IrClACHTUNRGTNEUNG(coe)2}2] (coe=cy-
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
clooctene) also realized high catalytic activity and produced
3a in 90% yield along with a small amount of 4a (7%;
Table 1, entry 9). However, other iridium complexes such as
AHCTUNGTRENNUNG
[{IrACHTUNGTRENNUNG(cod)(OH)}2] and [{IrCl2Cp*}2] (Cp*=1,2,3,4,5-penta-
A
ethanol (1j), n-butanol (1k) and n-octanol (1l) were tolerat-
ed as substrates in this reaction to produce the correspond-
ing hydroacylation products 3k–3m in moderate to good
yields together with the corresponding homoallylic alcohols
(4k, 4l, and 4m, respectively), which were formed as by-
products in 10–22% yield (Table 2, entries 10–12). This is
believed to be due to the difficulty of dehydrogenation of
initially formed aliphatic homoallylic alcohols compared
with that of benzylic homoallylic alcohols.
In contrast to the hydroacylation of 2a and 2b in which
the reaction smoothly proceeded with various alcohols,
when 4-methyl-2-pentyne (2c) was employed as the alkyne
substrate, the desired hydroacylation product (3n) was not
formed at all, but b,g-unsaturated ketones 5n was exclusive-
ly obtained in 81% isolated yield (Scheme 2). On the other
hydrogen-transfer process,[5,6] showed low or no catalytic ac-
tivity in the present reaction (Table 1, entries 10–11).
Under the optimized conditions shown in Table 1, entry 1,
the reaction of various primary alcohols 1 with 2-alkynes 2
was examined (Table 2). The reaction of 2a with benzylic al-
cohols that had electron-donating or -withdrawing groups on
the benzene ring (1b–1e) afforded the corresponding hydro-
acylation products 3b–e in 67–85% isolated yields (Table 2,
entries 1–4). Other primary alcohols such as furfuryl alcohol
(1 f), 2-thiophen methanol (1g), 2-naphthyl methanol (1h),
and cinnamyl alcohol (1i) also reacted with 2a to produce
3 f–3i in good yield (Table 2, entries 5–8).
The reaction of 1-phenyl-1-propyne (2b) with 1a gave 3j
in 70% yield (Table 2, entry 9). Aliphatic alcohols such as
1884
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Chem. Eur. J. 2010, 16, 1883 – 1888

Iridium-Catalyzed Coupling Reactions
FULL PAPER
Table 3. Ir-catalyzed coupling of aromatic aldehydes 6 with 2a leading to
hydroacylation products.[a]
Yield [%][b]
Scheme 2. Reaction of 1a with 2c.
Entry
Aldehyde 6
hand, the reaction of 2-hexyne (2d), which has a less bulky
substituent, with 1a gave rise to a mixture of 3o and 5o in a
ratio of 49:51 (Scheme 3). The above-mentioned results
1
R=H (6a)
84 (9:91)[c] (3a)
81 (64:36) (3b)
80 (57:43) (3c)
82 (14:86) (3d)
66 (21:79) (3e)
2[d]
3[d]
4
R=Me (6b)
R=MeO (6c)
R=Cl (6d)
R=CF3 (6e)
5
6[e]
7[e]
X=O (6 f)
X=S (6g)
70 (70:30) (3 f)
82 (55:45) (3g)
Scheme 3. Reaction of 1a with 2d.
8
strongly suggest that the resulting hydroacylation products 3
could be formed through the b,g-unsaturated ketones 5
from homoallylic alcohols 4 as intermediates, which lead to
hydroacylation products 3 (see below for further experimen-
tal elucidations). For the reaction of 2c with 1a, however,
the isomerization of b,g-unsaturated ketone 5n, which has
an anchoring bulky isopropyl group, to the a,b-unsaturated
ketone 3n may be difficult (Scheme 2).
To reveal the reaction pathway that involves the initial
formation of homoallylic alcohols as intermediates, the reac-
tion of aromatic aldehydes 6 with 2a under these reaction
conditions was examined (Table 3).
9[d,f]
[a] Conditions: Aldehyde 6 (0.5 mmol) was allowed to react with 2a
(2 mmol) in the presence of [{IrCl(cod)}2] (0.025 mmol) combined with P-
(n-oct)3 (0.1 mmol) in toluene (1 mL) at 1208C for 15 h. [b] Isolated
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
yields. The numbers in parentheses show the E/Z ratio estimated by
1H NMR spectroscopy. [c] 5a was formed in 6% yield as a by-product.
[d] [{IrClACHTNUTRGENN(UG cod)}2] (0.05 mmol) and PACHTNUGTREN(UNGN n-oct)3 (0.2 mmol) were used.
[e] Alkyne (4 mmol) was used. [f] Alkyne (5 mmol) was used.
As expected, various aromatic aldehydes 6a–6i reacted
with 2a to produce the corresponding hydroacylation prod-
ucts 3 in good yields (Table 3, entries 1–9). Note that this re-
action did not require the addition of 2-propanol, in contrast
with the Ru-catalyzed reaction of aldehydes with 2-butyne
reported by Krische and co-workers in which the reaction
requires the presence of 2-propanol.[9]
To obtain further insight about the reaction mechanism,
time-course monitoring of the reaction of 1a with 2a under
the conditions in Table 1, entry 1 was investigated. It was
found that 4a and 5a are observed as principal products at
the early stage of the reaction (<10 h). As the reaction pro-
ceeded, 4a and 5a disappeared and were converted to 3a
almost completely as the final product (Figure 1).
Figure 1. Time-course monitoring of the formation of 3a in the reaction
of 1a with 2a under the conditions in Table 1, entry 1.
Thus, we suppose that this reaction proceeds through de-
hydrogenation of 4a to give 5a, which is followed by isomer-
ization to 3a as the final product. In fact, the reaction of 4a
with 2a under the same conditions as showed in Table 1,
entry 1 resulted in the formation of 3a in 74% yield
(Scheme 4).
Although a detailed reaction mechanism of the present
coupling reaction has not been fully confirmed at this stage,
Scheme 4. Reaction of 4a with 2a.
Chem. Eur. J. 2010, 16, 1883 – 1888
ꢀ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
1885

Y. Obora, Y. Ishii and S. Hatanaka
Typical reaction conditions for the Ir-
catalyzed coupling of 1a with 2a
(Table 1, entry 1): A mixture of [{IrCl-
A
ACHTUNGTRENNUNG
0.5 mmol), and 2a (54 mg, 1 mmol) in
toluene (1 mL) was stirred at 1208C
for 15 h under Ar in a pressure tube.
The conversions and yields of the
products were estimated from peak
areas based on an internal standard by
using GC, and the product 3a was ob-
tained (yield=94%) along with
a
trace amount of 5a. A mixture of the
product 3a (E,Z mixture) and 5a was
separated by column chromatography
(230–400 mesh silica gel, n-hexane/
ethyl acetate=20/1) and was distilled
by Kugelrohr distillation to give 3a
(yield=74 mg, 92%).
Scheme 5. A plausible reaction pathway for the formation of 3 via 4 and 5 as possible intermediates.
Typical reaction conditions for the Ir-
catalyzed coupling of
6
with 2a
(n-
it is possible to explain the reaction rationally by the path-
way shown in Scheme 5. First, the reaction initiates the hy-
drogen transfer from alcohols 1 to an iridium complex to
produce aldehydes 6 and an iridium–hydride complex,
(Table 3, entry 1): A mixture of [{IrCl(cod)}2] (16 mg, 0.025 mmol), PACHTUNGTRENNUNG
T
oct)3 (37 mg, 0.1 mmol), 6a (53 mg, 0.5 mmol), and 2a (108 mg, 2 mmol)
in toluene (1 mL) was stirred at 1208C for 15 h under Ar in a pressure
tube. The conversions and yields of the products were estimated from
peak areas based on an internal standard by using GC, and the product
3a was obtained (yield=91%). The product 3a (E,Z mixture) was isolat-
ed by column chromatography (230–400 mesh silica gel, n-hexane/ethyl
acetate=20/1) and was distilled by Kugelrohr distillation to give 3a
(yield=67 mg, 84%).
which then reacts with alkynes 2 to form the hydrido
ACHTUNGTRENNUNG
ACHTUNGTRNE(NUNG p-all-
yl)iridium (A) as previously reported.[7] Thereafter, the
formed A reacts with aldehydes through a six-membered in-
termediate B to form homoallylic alcohols 4.[7] Subsequently,
dehydrogenation of the resulting 4 followed by isomeriza-
tion would lead to the desired hydroacylation products 3.[10]
Reaction of 4a with 2a (Scheme 4): A mixture of [{IrCl
ACHTUNGTERN(NUNG cod)}2] (16 mg,
0.025 mmol), P(n-oct)3 (37 mg, 0.1 mmol), 4a (81 mg, 0.5 mmol), and 2a
AHCTUNGTRENNUNG
(54 mg, 1 mmol) in toluene (1 mL) was stirred at 1208C for 15 h under
Ar in pressure tube. The conversions and yields of the products were esti-
mated from peak areas based on an internal standard by using GC, and
the product 3a was obtained (74% yield).
Conclusion
Characterization data
3b (Z isomer): 1H NMR (400 MHz, CDCl3): d=7.88–7.19 (m, 4H), 5.75
In conclusion, we have reported a novel Ir-catalyzed cou-
pling reaction of primary alcohols with 2-alkynes leading to
hydroacylation products such as a,b-unsaturated ketones in
good to excellent yields. The experimental mechanistic in-
vestigations revealed that the reaction would proceed
through the initial formation of homoallylic alcohols, fol-
lowed by dehydrogenation and isomerization to lead to hy-
droacylation products. Further investigation with regard to
the detailed reaction mechanism is currently in progress.
(qq, 3J
ACHTUNGTRENNUNG
(dq, 3J
AHCTUNGTRENNUNG
O), 144.1 (C), 136.6 (C), 134.0 (C), 129.4 (CH), 128.7 (CH), 126.1 (C=
CH), 21.5 (PhCH3), 21.2 (CH3), 15.4 ppm (CH3); IR (neat): u˜ =3028,
2976, 2916, 1646, 1602, 1450, 1274, 1167, 975, 823, 739 cmÀ1; MS (EI,
70 eV): m/z (%): 174 [M+] (14), 160 (10), 159 (86), 131 (16), 119 (100),
91 (64), 65 (27), 55 (12); HRMS: (EI, 70 eV): m/z calcd for C12H14O
[M+]: 174.1045; found: 174.1050.
3c (E,Z mixture): 1H NMR (400 MHz, CDCl3) for the E isomer: d=
7.94–6.82 (m, 4H), 6.32 (q, 3J
ACHTUNGTRENNUNG
(m, 3H), 1.87 ppm (d, 3J
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
13C NMR (100 MHz, CDCl3) for the E,Z mixture: d=199.4, 197.8 (2C=
O, E- and Z-isomer), 163.7, 162.4 (2C, E- and Z-isomers), 138.9 (C=CH,
E-isomer), 137.5, 136.6 131.0, 129.4 (4C, E- and Z-isomers) 131.6, 113.9,
113.3 (4CH, E- and Z-isomer), 125.5 (C=CH, Z-isomer), 55.4, 55.4
(2CH3O, E- and Z-isomers), 21.2, 12.6 (2CH3, E- and Z-isomers), 15.3
(CH3, Z-isomer), 14.5 ppm (CH3, E-isomer); IR (neat): u˜ =2992, 2941,
1653, 1596, 1507, 1247, 1150, 978, 841, 749, 600 cmÀ1; MS (EI, 70 eV) for
the E isomer: m/z (%): 190 [M+] (22), 175 (11), 159 (13), 135 (100), 107
(13), 92 (12), 77 (20); HRMS (EI, 70 eV): m/z calcd for C12H14O2 [M]+:
190.0994; found: 190.0986; MS (EI) for the Z isomer: m/z (%): 190 [M+]
(17), 175 (25), 173 (11), 159 (24), 135 (100), 107 (16), 92 (16), 77 (26);
HRMS (EI, 70 eV): m/z calcd for C12H14O2 [M+]: 190.0994; found:
190.0996.
Experimental Section
GC analysis was performed with a flame ionization detector using a
0.22 mmꢁ25 m capillary column (BP-5). 1H and 13C NMR spectra were
measured at 400 and 100 MHz, respectively, in CDCl3 with Me4Si as the
internal standard. The products were characterized by 1H NMR,
13C NMR, NOESY, DEPT, HMQC spectroscopy and by GC–MS. The
yields of the products were estimated from the peak areas based on the
internal standard technique by using GC. All starting materials were
commercially available and were used without any purification. Com-
pounds 3a (E isomer,[11] Z isomer),[12] 3b (E isomer),[11] 3d (E isomer,[13]
Z isomer),[14] 3 f (E isomer, Z isomer),[15] 3g (E isomer),[11] 3i (E,E
isomer),[16] 3j (E isomer,[17] Z isomer),[18] 3k (E isomer,[19] Z isomer),[20] 3l
(E isomer),[19] 3o (E isomer, Z isomer),[21] 4a,[22] 4k,[7] 4l,[7] 4m,[7] and
5a[23] have been previously reported.
3e (E,Z mixture): 1H NMR (400 MHz, CDCl3) for the E isomer: d=
8.02–7.65 (m, 4H), 6.41 (q, 3J
N
3
1.91 ppm (d, J
N
1886
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Chem. Eur. J. 2010, 16, 1883 – 1888

Iridium-Catalyzed Coupling Reactions
FULL PAPER
3
isomer: d=8.02–7.65 (m, 4H), 5.89 (qq, J
(H,H)=7, 2 Hz, 1H), 1.99–1.97
ACTHNGUTERNNUG
1.30–1.20 (m, 8H), 0.86 ppm (t, 3J(H,H)=7 Hz, 3H); 13C NMR
(m, 3H), 1.52 ppm (dq, 3J
(H,H)=7, 2 Hz, 3H); 13C NMR (100 MHz,
(100 MHz, CDCl3) for the E isomer: d=201.1 (C=O), 143.9 (C), 136.1
(C), 137.5 (C=CH), 129.6 (CH), 128.2 (CH), 127.3 (CH), 39.5 (CH2), 31.6
(CH2), 29.5 (CH2), 29.2 (CH2), 29.1 (CH2), 22.6 (CH2), 15.5 (CH3),
14.0 ppm (CH3); 13C NMR (100 MHz, CDCl3) for the Z isomer: d=207.1
(C=O), 144.3 (C), 138.1 (C), 129.5 (C=CH), 128.6 (CH), 127.5 (CH),
126.9 (CH), 43.0 (CH2), 31.6 (CH2), 29.3 (CH2), 29.0 (CH2), 23.8 (CH2),
23.7 (CH2), 15.4 (CH3), 14.0 ppm (CH3); IR (neat): u˜ =2920, 2855, 1692,
1625, 1494, 1132, 1069, 760, 702 cmÀ1; MS (EI, 70 eV) for the E isomer:
m/z (%): 244 [M+] (14), 229 (16), 160 (59), 145 (33), 117 (100), 115 (42),
91 (19), 57 (17); HRMS: (EI, 70 eV): m/z calcd for C17H24O [M+]:
244.1827; found: 244.1836; MS (EI, 70 eV) for the Z isomer: m/z (%):
244 [M+] (14), 160 (24), 145 (22), 117 (100), 115 (28), 91 (14), 57 (12);
HRMS: (EI, 70 eV): m/z calcd for C17H24O [M+]: 244.1827; found
244.1833.
CDCl3) for the E isomer: d=197.4 (C=O), 143.3 (C=CH), 142.2 (C),
137.7 (C), 132.8 (C), 132.4 (CH), 129.2 (CH), (125.07, 125.04, 125.00,
124.96) (CF3), 14.9 (CH3), 11.8 ppm (CH3); 13C NMR (100 MHz, CDCl3)
for the Z isomer: d=199.4 (C=O), 139.5 (C), 135.7 (C), 134.4 (q, J-
ACHTUNGTRENNUNG(C,F)=33 Hz, C), 129.4 (CH), 128.5 (C=CH), 126.8 (q, JACHUTNGTREN(NNGU C,F)=4 Hz,
CH), 20.9 (CH3), 15.6 ppm (CH3); 19F NMR (376 MHz, CDCl3) for the E
isomer: d=62.9 ppm; 19F NMR (376 MHz, CDCl3) for the Z isomer: d
=63.1 ppm; IR (neat) for the E,Z mixture: u˜ =3044, 2975, 2929, 2801,
1642, 1402, 1321, 1270, 841, 755 cmÀ1; MS (EI, 70 eV) for the E isomer:
m/z (%): 228 [M+] (32), 213 (29), 200 (13), 173 (100), 159 (83), 145 (88),
95 (16), 83 (38), 75 (9), 55 (58); HRMS: (EI, 70 eV): m/z calcd for
C12H11OF3 [M]+: 228.0762; found: 228.0770; MS (EI, 70 eV) for the Z
isomer: m/z (%): 228 [M+] (21), 227(13), 213 (25), 173 (78), 159 (100),
145 (87), 131 (15), 95 (15), 83 (18), 75 (9), 55 (49); HRMS (EI, 70 eV):
m/z calcd for C12H11OF3 [M+]: 228.0762; found: 228.0758.
5n: 1H NMR (400 MHz, CDCl3): d=7.98–7.40 (m, 5H), 5.89 (dt, 3J-
ACHUTNGRENNUG ACHTUNTGREN(NUGN H,H)=9 Hz, 1H),
(H,H)=19, 9 Hz, 1H), 5.18–5.14 (m, 2H), 3.78 (t, 3J
2.30–2.16 (m, 1H), 0.93 ppm (m, 6H); 13C NMR (100 MHz, CDCl3): d=
201.6 (C=O), 137.3 (CH), 136.2 (C), 132.9 (CH), 128.5 (CH), 128.3 (CH),
118.3 (CH2), 59.3 (CH), 30.6 (CH), 21.3 (CH3), 19.7 ppm (CH3); IR
(neat): u˜ =3066, 2956, 1682, 1594, 1442, 1202, 999, 919, 839, 759,
707 cmÀ1; MS (EI, 70 eV): m/z (%): 188 [M+] (1), 170 (2), 145 (2), 115
(2), 105 (100), 77 (34), 55 (3), 51 (7); HRMS: (EI, 70 eV): m/z calcd for
C13H16O [M+]: 188.1201; found: 188.1205.
3g (Z isomer): 1H NMR (400 MHz, CDCl3) : d=7.64 (dd, 3J
1 Hz, 1H), 7.55 (dd, 3J(H,H)=4, 1 Hz, 1H), 7.09 (dd, 3J
(H,H)=5, 4 Hz,
1H), 5.73 (qq, 3J
(H,H)=7, 2 Hz, 1H), 2.00–1.98 (m, 3H), 1.60 ppm (dq,
3J(H,H)=7, 2 Hz, 3H); 13C NMR (100 MHz, CDCl3): d=190.1 (C=O),
147.2 (C), 134.6 (CH), 134.1 (CH), 128.2 (CH), 136.6 (C), 126.2 (C=CH),
21.1 (CH3), 15.6 ppm (CH3); IR (neat): u˜ =3100, 2968, 2849, 1658, 1506,
1350, 1270, 1150, 1047, 959, 831, 727 cmÀ1; MS (EI, 70 eV): m/z (%): 166
[M+] (18), 151 (34), 133 (53), 111 (100), 105 (16), 83 (14), 55 (16);
HRMS: (EI, 70 eV): m/z calcd for C9H10OS [M+]: 166.0452; found:
166.0451.
ACHTUNGTRENN(UNG H,H)=5,
G
ACHTUNGTRENNUNG
ACHTUNGTRENNUNG
ACHTUNGTRENNUNG
5o: 1H NMR (400 MHz, CDCl3): d=8.00–7.37 (m, 5H), 5.91 (ddd, 3J-
ACHUTNGRENNUG CAHTUNGTRENNUNG
(H,H)=18, 10, 7 Hz, 1H), 5.19–5.13 (m, 2H), 4.06 (dd, 3J
ACHTUNGTRENNUNG
7 Hz, 3H); 13C NMR (100 MHz, CDCl3): d=201.2 (C=O), 137.2 (CH),
136.8 (C), 132.9 (CH), 128.6 (CH), 128.4 (CH), 117.3 (CH2), 51.5 (CH),
34.3 (CH2), 20.4 (CH2), 14.0 ppm (CH3); IR (neat): u˜ =3050, 2960, 1682,
1446, 1230, 991, 915, 703 cmÀ1; MS (EI, 70 eV): m/z (%): 188 [M+] (3),
145 (1), 120 (1), 106 (11), 105 (100), 77 (40), 51 (8); HRMS: (EI, 70 eV):
m/z calcd for C13H16O [M+]: 188.1201; found: 188.1208.
3h (E,Z mixture): 1H NMR (400 MHz, CDCl3) for the E isomer: d=
8.42–7.48 (m, 7H), 6.46 (q, 3J
A
3
1.90 ppm (d, J
N
isomer: d=8.42–7.48 (m, 7H), 5.86 (q, 3J
(m, 3H), 1.55 ppm (d, J
(H,H)=7 Hz, 3H); 13C NMR (100 MHz, CDCl3)
for the E,Z mixture: d=200.7, 198.9 (2C=O, E and Z isomers), 141.3 (C=
CH, E-isomer), 137.8, 136.5, 136.0, 135.7, 134.7, 133.8, 132.7, 132.2 (8C,
E- and Z-isomers), 131.6, 130.1, 129.6, 129.0, 128.6, 128.5, 127.9, 127.8,
127.7, 127.6, 126.7, 126.5, 125.7, 124.3 (14CH, E- and Z-isomers) 126.8
(C=CH, Z-isomer), 21.28, 21.29 (2CH3, E- and Z-isomers), 15.5 (CH3, Z-
isomer), 14.8 ppm (CH3, E-isomer); IR (neat): u˜ =3055, 2974, 2917, 1640,
1466, 1356, 1281, 1160, 1120, 821, 757, 717 cmÀ1; MS (EI, 70 eV) for the
E isomer: m/z (%): 210 [M+] (29), 195 (50), 167 (29), 155 (93), 127 (100),
77 (13), 55 (13); HRMS: (EI, 70 eV): m/z calcd for C15H14O [M+]:
210.1045; found: 210.1046; MS (EI, 70 eV) for the Z isomer: m/z (%):
210 [M+] (47), 195 (66), 167 (23), 155 (71), 127 (100), 77 (13), 55 (13);
HRMS: (EI, 70 eV): m/z calcd for C15H14O [M+]: 210.1045; found:
210.1038.
Acknowledgements
This work was supported by a Grant-in-Aid for Scientific Research from
the Ministry of Education, Culture, Sports, Science and Technology,
Japan, “High-Tech Research Center” Project for Private Universities:
matching fund subsidy from the Ministry of Education, Culture, Sports,
Science and Technology, 2005–2009.
3i (E,Z isomer): 1H NMR (400 MHz, CDCl3): d=7.62–7.26 (m, 7H), 5.81
(qq, JACHTUNGTRENNUNG(H,H)=7,2 Hz, 1H), 1.97–1.95 (m, 3H), 1.75 ppm (dq, JHCATUNGTRENN(UGN H,H)=7,
[1] a) G. C. Fu, Modern Rhodium-Catalyzed Organic Reactions (Ed.:
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a) K. Kokubo, K. Matsumasa, M. Miura, M. Nomura, J. Org. Chem.
1997, 62, 4564; b) C.-H. Jun, H. Lee, J.-B. Hong, B.-I. Kwon, Angew.
Chem. 2002, 114, 2250; Angew. Chem. Int. Ed. 2002, 41, 2146;
c) M. C. Willis, H. E. Randell-Sly, S. Brayshaw, G. S. Currie, Org.
Lett. 2005, 7, 2249; d) G. L. Moxham, H. E. Randell-Sly, S. K. Bray-
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2006, 118, 7780; Angew. Chem. Int. Ed. 2006, 45, 7618; e) M. C.
Willis, H. E. Randell-Sly, R. L. Woodward, S. McNally, G. S. Currie,
J. Org. Chem. 2006, 71, 5291; f) X. Y. Rueda, S. Castillon, J. Organo-
met. Chem. 2007, 692, 1628; g) G. L. Moxham, H. E. Randell-Sly,
3
3
2 Hz, 3H); 13C NMR (100 MHz, CDCl3): d=198.6 (C=O), 144.8 (CH),
130.5 (CH), 128.7 (CH), 128.3 (CH), 126.1 (CH), 136.8, 134.7 (C), 128.9
(C=CH), 20.8 (CH3), 15.6 ppm (CH3); IR (neat): u˜ =3066, 3014, 2921,
1652, 1600, 1449, 1073, 980, 750, 690 cmÀ1; MS (EI, 70 eV): m/z (%): 186
[M+] (10), 159 (10), 131 (100), 103 (53), 77 (27), 43 (22); HRMS: (EI,
70 eV): m/z calcd for C13H14O [M+]: 186.1045; found: 186.1043.
3l (Z isomer): 1H NMR (400 MHz, CDCl3): d=7.39–7.08 (m, 5H), 5.99
(q, 3J(H,H)=7 Hz, 1H), 2.43 (t, 3J(H,H)=7 Hz, 2H), 1.90 (d, 3J
ACHTUNGTRENNUNG ACHTUNGTENRNUG ACTUHNGTRENNUGN
7 Hz, 3H), 1.64–1.58 (m, 2H), 0.88 ppm (t, 3J
ACHTUNGTRENNUNG
13C NMR (100 MHz, CDCl3): d=206.9 (C=O), 144.3 (C), 138.0 (C), 129.5
(C=CH), 128.6 (CH), 127.5 (CH), 126.9 (CH), 44.9 (CH2), 17.2 (CH2),
15.4 (CH3), 13.7 ppm (CH3); IR (neat): u˜ =3053, 2963, 2934, 1673, 1591,
1494, 1379, 1141, 760, 702 cmÀ1; MS (EI, 70 eV): m/z (%): 188 [M+] (25),
173 (5), 145 (17), 118 (11), 117 (100), 91 (15), 43 (12); HRMS: (EI): m/z
calcd for C13H16O [M+]: 188.1201; found: 188.1195.
3m (E,Z mixture): 1H NMR (400 MHz, CDCl3) for the E isomer: d=
7.39–7.08 (m, 5H), 6.96 (q, 3J
(H,H)=7 Hz, 1H), 2.52 (t, 3J
N
3
2H), 1.71 (d, J
U
0.86 ppm (t, 3J
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
A
ACHTUNGTRENNUNG
Chem. Eur. J. 2010, 16, 1883 – 1888
ꢀ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
1887

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Received: September 25, 2009
Published online: December 22, 2009
1888
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ꢀ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2010, 16, 1883 – 1888