Chiral amidophosphane-rhodium(I)-catalyzed asymmetric conjugate arylation of acyclic enones with arylboronic acids

Article abstract of DOI:10.1248/cpb.57.1024

A catalytic asymmetric conjugate arylation of acyclic α, β-unsaturated ketones with arylboronic acids was catalyzed by 3 mol% of chiral amidomonophosphane 1-rhodium(I) in the presence of potassium hydroxide in a mixture of 1,4-dioxane and water at 70 °C t

Full text of DOI:10.1248/cpb.57.1024

1024
Notes
Chem. Pharm. Bull. 57(9) 1024—1027 (2009)
Vol. 57, No. 9
Chiral Amidophosphane–Rhodium(I)-Catalyzed Asymmetric Conjugate
Arylation of Acyclic Enones with Arylboronic Acids
Qian CHEN,a Masami KURIYAMA,b Xinyu HAO,b Takahiro SOETA,b Yasutomo YAMAMOTO,b
Ken-ichi YAMADA,b and Kiyoshi TOMIOKA*,b
a The Academy of Fundamental and Interdisciplinary Science, Harbin Institute of Technology; Harbin, Heilongjiang
150080, P. R. China: and b Graduate School of Pharmaceutical Sciences, Kyoto University; Yoshida, Sakyo-ku, Kyoto
606–8501, Japan. Received June 5, 2009; accepted June 27, 2009; published online June 30, 2009
A catalytic asymmetric conjugate arylation of acyclic a,b-unsaturated ketones with arylboronic acids was
catalyzed by 3 mol% of chiral amidomonophosphane 1–rhodium(I) in the presence of potassium hydroxide in a
mixture of 1,4-dioxane and water at 70 °C to afford 1,4-conjugate arylated acyclic ketones with high enantio-
meric excess in high chemical yield. Thirteen examples of the reaction demonstrate the general applicability of
the catalytic system.
Key words catalytic asymmetric reaction; arylation; arylboronic acid; conjugate addition; a,b-unsaturated ketone
The carbon–carbon bond forming catalytic asymmetric
Non-3-ene-2-one (7a) was then selected as the second ac-
conjugate addition reaction of a,b-unsaturated carbonyl ceptor because of the simple methyl ketone structure (Table
compounds with organometallic reagents has been the sig- 1). The phenylation of 7a with 5 eq of phenylboronic acid
nificant milestone of catalytic asymmetric reactions.1—5) (5a) was catalyzed by 3 mol% of 1–rhodium(I) in a 10 : 1
Tremendous efforts on the discovery of efficient chiral mixture of 1,4-dioxane and water.27) Although the chemical
sources for the reaction with carbon- and hetero-nucleophiles yield was not high under the catalysis of 1–acetylacetonato-
provided a fruit of chiral sources like phosphorous com- bis(diethylene)rhodium(I), the desired ketone 8aa12,33) with
pounds.6) A touchstone for the evaluation of chiral sources 56% ee was obtained in 35% isolated yield (Table 1, entry 1).
has been the asymmetric reaction of cyclohexenone 2 with Enantioselectivity (ee%) was determined by HPLC with chi-
diorganozinc–copper(I),7,8) Grignard reagent–copper(I)9,10) or ral stationary phase (Daicel Chiralcel OB-H, hexane/2-
arylboronic acid–rhodium(I)11—18) reagent–catalyst combina- propanolꢀ100/1, 0.5 ml/min, 254 nm) as described in Exper-
tions. We have also engaged in this fascinating challenge and imental. Other two N-Boc-valine-connected amidophos-
fortunately succeeded in the development of chiral ami- phanes 9 and 1034) (Fig. 1) exhibited the same level of per-
dophosphane 1-based catalytic asymmetric conjugate addi- formance to give 8aa with 65% and 61% ees, respectively
tion reaction of 2 with organometallic reagents, especially, (entries 2, 3). The sense of asymmetric induction was con-
Grignard reagents19—21) and diorganozincs.22—26) Especially, trolled by the pyrrolidine part of the ligands and not by the
1–rhodium(I) catalyzed asymmetric conjugate arylation of 2 stereochemistry of the valine moiety; 8aa of the same ab-
with arylboronic acids gave 3 with excellently high ee of up
to 99% (Chart 1).27—30) However, there has been known the
presence of a large gap in reaction efficiency between the
arylation of cyclic and acyclic enones probably due to s-trans
and s-cis conformation differences of enones. Now we de-
scribe a catalytic asymmetric arylation of acyclic enones 7
with arylboronic acids 5 yielding arylation products 8 with
Chart 2. Attempted Arylation of 4-Methylbenzylidenemalonate 4
relatively high ee.
Acyclic Enones as Good Acceptors for Conjugate
Table 1. Catalytic Asymmetric Conjugate Phenylation of 7a
Phenylation At the beginning of this arylation study 4-
methylbenzylidenemalonate 431,32) was examined with its ac-
ceptor ability by treating with phenylboronic acid (5a) in a
10 : 1 mixture of 1,4-dioxane and water under the catalysis of
1–rhodium(I). Unfortunately, the starting 4 was recovered al-
most quantitatively without detectable production of adduct 6
(Chart 2). This disaster was overcome by the selection of
enone 7 as an acceptor for the conjugate arylation.
Temp.
(°C)
Time
(h)
Yield
(%)
ee
(%)
Entry Ligand
X
Base
1
2
3
4
5
6
7
8
9
1
9
10
1
1
1
9
1
1
acac
acac
acac
Cl
Cl
Cl
Cl
Cl
Cl
none
none
none
KOH
K3PO4
Et3N
KOH
KOH
KOH
100
100
100
100
100
100
100
70
3
1
1
35
58
61
96
90
70
82
90
37
56
65
61
76
72
75
63
81
67
7
15
15
31
20
23
50
Chart 1. Catalytic Asymmetric Conjugate Arylation of Cyclohexenone
© 2009 Pharmaceutical Society of Japan
∗ To whom correspondence should be addressed. e-mail: tomioka@pharm.kyoto-u.ac.jp

September 2009
1025
solute configuration was obtained in the similar level of ported. The absolute stereochemistry of other products 8 was
enantioselectivity.
presented by analogy.
The reaction was much more improved by using 1–chloro-
bis(ethylene)rhodium(I) complex in the presence of potas- Conclusion
sium hydroxide at 100 °C for 7 h to give 8aa with 76% ee in
The combination of a chiral amidophosphane, chloro-
96% yield (entry 4). Other bases, potassium phosphate and bis(ethylene)rhodium dimer, and potassium hydroxide was
triethylamine, also gave the similar level of efficiency (en- proven to be a good chiral catalyst for the asymmetric conju-
tries 5, 6). N-Boc-L-valine-connected amidophosphane 9 was gate arylation of acyclic enones with arylboronic acid in a
not a better ligand than 1 to give 8aa with 63% ee (entry 7). 10 : 1 mixture of 1,4-dioxane and water. It is important to
Best efficiency was obtained at 70 °C reaction temperature note that not only cyclic enones of s-trans conformation but
for 20 h to give 8aa with 81% ee in 90% yield (entries 8, 9).
also acyclic enones of possible s-cis conformation are the
Generality in Catalytic Asymmetric Conjugate Aryla- substrate for the present catalytic asymmetric conjugate ary-
tion The established conditions above were applied to the lation with arylboronic acids, although the enantioselectivity
catalytic asymmetric conjugate arylation of six acyclic is not so high. Further studies towards higher enantioselectiv-
enones 7a—f with five arylboronic acids 5a—e under the ity are the current focus of our efforts.
catalysis of 1–rhodium(I) in the presence of one equiv of
Experimental
potassium hydroxide in a 10 : 1 mixture of 1,4-dioxane and
water at 70 °C as has been summarized in Table 2.
General Procedure. (R)-4-Phenylnonan-2-one (8aa)12) (Table 1, Entry
8) 1,4-Dioxane (2.5 ml), 4 M aqueous KOH (0.25 ml), and 7a (140 mg,
The similar level of relatively high enantioselectivity, 76%
and 78% ees, were obtained with the use of substituted
phenylboronic acids bearing electron-donating methoxy and
withdrawing phenyl groups (Table 2, entries 1, 2). Relatively
bulky isopropyl substituent at the reaction site of enone 7b
did not disturb the reaction to give the arylation products
with 76—86% ee (entries 3—6). A phenyl group bearing an
electron-withdrawing trifluoromethyl substituent was intro-
duced in the best enantioselectivity of 86% (entry 5). The
phenyl group at the reaction site of 7c was deleterious to the
enantioselectivity to give arylation products with 65% and
60% ees (entries 7, 8). Although ethylketone 7d was usable
as an acceptor with 72% and 74% enantioselectivity,
phenylketones 7e and 7f were the worst acceptors giving
51% selectivity (entries 9, 10). The sense of asymmetric in-
1.0 mmol) were added to a mixture of [RhCl(C2H4)2]2 (5.8 mg, 0.015 mmol),
1 (11.6 mg, 0.033 mmol), and 5a (610 mg, 5.0 mmol) under argon. The mix-
ture was stirred at 70 °C for 20 h. After dilution with EtOAc (40 ml), the
mixture was washed with 10% NaOH (10 ml) and brine (20 ml), and then
dried over Na2SO4. Concentration and silica gel column chromatography
(hexane/AcOEtꢀ30/1) gave 8aa (90%) as colorless oil: [a]D20 ꢁ15.1 (cꢀ1.1,
CHCl3). 81% ee (HPLC: Daicel Chiralcel OB-H, hexane/i-PrOHꢀ100/1,
1
0.5 ml/min, 254 nm; major 16.7 min, minor 13.4 min). H-NMR (500 MHz,
CDCl3) d: 0.82 (t, Jꢀ7.0 Hz, 3H), 1.10—1.23 (m, 6H), 1.55—1.63 (m, 2H),
2.01 (s, 3H), 2.69 (dd, Jꢀ7.3, 16.2 Hz, 1H), 2.73 (dd, Jꢀ7.6, 16.2 Hz, 1H),
3.10 (m, 1H), 7.16—7.31 (m, 5H). 13C-NMR (125 MHz, CDCl3) d: 14.0,
22.4, 27.0, 30.6, 31.7, 36.4, 41.3, 50.9, 126.2, 127.4, 128.4, 144.6, 208.1. IR
(neat) cmꢁ1: 1710. MS m/z: 218 (Mꢂ).
(R)-4-(3-Methoxyphenyl)nonan-2-one (8ab)14) (Table 2, Entry 1) Elu-
ent, hexane/AcOEtꢀ40/1. Colorless oil. [a]D20 ꢁ13.9 (cꢀ1.05, CHCl3). 76%
ee (OB-H, hexane/i-PrOHꢀ100/1, 0.5 ml/min, 254 nm; major 38.1 min,
minor 23.4 min). 1H-NMR d: 0.82 (t, Jꢀ7.0, 3H), 1.17—1.24 (m, 6H),
1.52—1.62 (m, 2H), 2.03 (s, 3H), 2.67 (dd, Jꢀ7.0, 16.0, 1H), 2.72 (dd,
duction was determined as indicated by the comparison of Jꢀ7.4, 16.0, 1H), 3.07 (m, 1H), 3.79 (s, 3H), 6.72—6.78 (m, 3H), 7.20 (dd,
Jꢀ8.0, 8.0, 1H). 13C-NMR d: 13.9, 22.4, 27.0, 30.6, 31.7, 36.3, 41.3, 50.8,
the sign of the specific rotation of 8da and 8fa with those re-
55.1, 111.2, 113.5, 119.9, 129.4, 146.4, 159.7, 208.1. IR (neat): 1716. MS
m/z: 248 (Mꢂ).
(R)-4-(4-Phenylphenyl)nonan-2-one (8ae) (Entry 2) Eluent, hexane/
AcOEtꢀ50/1. White solid. mp 46—48 °C. [a]D20 ꢁ11.7 (cꢀ0.99, CHCl3).
78% ee (AD-H, hexane/i-PrOHꢀ100/1, 0.5 ml/min, 254 nm; major
1
18.7 min, minor 20.6 min). H-NMR d: 0.84 (t, Jꢀ7.6, 3H), 1.16—1.25 (m,
6H), 1.55—1.65 (m, 2H), 2.04 (s, 3H), 2.72 (dd, Jꢀ7.0, 16.2, 1H), 2.76 (dd,
Fig. 1. N-Boc-L- and D-Valine Connected Amidophosphanes 9 and 10
Table 2. Catalytic Asymmetric Conjugate Arylation of Acyclic Enones 7
Jꢀ7.4, 16.2, 1H), 3.16 (m, 1H), 7.24 (d, Jꢀ8.0, 2H), 7.32 (t, Jꢀ7.5, 1H),
Entry
7
R1
R2
5
Ar
Time (h)
8
Yield (%)
ee (%)
1
2
3
4
5
6
7
8
9
7a
7a
7b
7b
7b
7b
7c
7c
7d
7d
7e
7f
n-Pen
n-Pen
i-Pr
i-Pr
i-Pr
i-Pr
Ph
Ph
Me
Me
n-Pen
Me
Me
Me
Me
Me
Me
Me
Me
Me
Et
5b
5e
5a
5b
5c
5e
5d
5e
5a
5e
5a
5a
3-MeOC6H4
4-PhC6H4
Ph
3-MeOC6H4
4-CF3C6H4
4-PhC6H4
4-MeOC6H4
4-PhC6H4
Ph
11
17
21
21
22
26
26
5
10
24
22
7
8ab
8ae
8ba
8bb
8bc
8be
8cd
8ce
8da
8de
8ea
8fa
87
82
83
80
81
95
88
94
92
99
71
75
76
78
76
77
86
79
65
60
72R
74
51
10
11
12
Et
Ph
Ph
4-PhC6H4
Ph
Ph
51R

1026
Vol. 57, No. 9
(R)-1,3-Diphenyloctan-1-one (8ea)37) (Entry 11) Eluent, hexane/
AcOEtꢀ20/1. White solid. mp 63—64 °C. [a]D20 ꢂ1.3 (cꢀ1.1, CHCl3). 51%
ee (AD, hexane/i-PrOHꢀ100/1, 0.5 ml/min, 254 nm; major 19.1 min, minor
15.0 min). 1H-NMR: 0.82 (t, Jꢀ6.4, 3H), 1.19—1.26 (m, 6H), 1.60—1.72
(m, 2H), 3.20—3.35 (m, 3H), 7.17 (t, Jꢀ7.5, 1H), 7.22 (d, Jꢀ7.5, 2H), 7.28
(dd, Jꢀ7.5, 7.5, 2H), 7.43 (dd, Jꢀ7.5, 7.5, 2H), 7.53 (t, Jꢀ7.5, 1H), 7.89 (d,
Jꢀ7.5, 2H). 13C-NMR: 13.9, 22.4, 27.1, 31.7, 36.2, 41.1, 45.9, 126.2, 127.6,
128.0, 128.4, 128.5, 132.9, 137.3, 145.0, 199.3. IR (neat): 1680. MS m/z:
280 (Mꢂ).
7.42 (dd, Jꢀ7.5, 8.0, 2H), 7.52 (d, Jꢀ8.0, 2H), 7.57 (d, Jꢀ8.0, 2H). 13C-
NMR d: 13.9, 22.4, 27.0, 30.6, 31.7, 36.4, 40.8, 50.8, 126.96, 127.07,
127.14, 127.9, 128.7, 139.2, 140.9, 143.8, 208.1. IR (KBr): 1713. MS m/z:
294 (Mꢂ). Anal. Calcd for C21H26O: C, 85.67; H, 8.90. Found: C, 85.43; H,
8.99.
(S)-5-Methyl-4-phenylhexan-2-one (8ba)12) (Entry 3) Eluent, hexane/
AcOEtꢀ50/1. Colorless oil. [a]D20 ꢁ25.7 (cꢀ1.2, CHCl3). 76% ee (OD-H,
hexane/i-PrOHꢀ50/1, 0.5 ml/min, 254 nm; major 26.4 min, minor 23.1 min).
1H-NMR d: 0.74 (d, Jꢀ6.7, 3H), 0.93 (d, Jꢀ6.7, 3H), 1.83 (m, 1H), 1.98 (s,
3H), 2.75—2.83 (m, 2H), 2.91 (m, 1H), 7.13—7.20 (m, 3H), 7.25—7.29 (m,
2H). 13C-NMR d: 20.2, 20.6, 30.5, 33.2, 47.6, 48.0, 126.3, 128.2, 128.3,
143.3, 208.5. IR (neat): 1716. MS m/z: 190 (Mꢂ).
(R)-1,3-Diphenylbutan-1-one (8fa)38) (Entry 12) Eluent, hexane/
AcOEtꢀ50/1. White solid. mp 50—51 °C. [a]D25 ꢁ7.8 (cꢀ2.65, CCl4); lit.
[a]D25 ꢁ14.6 (cꢀ1.8, CCl4) for R. 51% ee (AD, hexane/i-PrOHꢀ100/1,
0.5 ml/min, 254 nm; major 10.7 min, minor 8.6 min). 1H-NMR: 1.33 (d,
Jꢀ7.0, 3H), 3.19 (dd, Jꢀ8.3, 16.5, 1H), 3.30 (dd, Jꢀ5.5, 16.5, 1H), 3.50 (m,
1H), 7.20 (m, 1H), 7.26—7.32 (m, 4H), 7.44 (dd, Jꢀ7.5, 7.5, 2H), 7.55 (t,
Jꢀ7.5, 1H), 7.92 (d, Jꢀ7.5, 2H). 13C-NMR: 21.8, 35.5, 47.0, 126.3, 126.9,
128.1, 128.56, 128.59, 133.0, 137.2, 146.6, 199.2. IR (neat): 1682. MS m/z:
224 (Mꢂ).
(S)-4-(3-Methoxyphenyl)-5-methylhexan-2-one (8bb)14) (Entry 4)
Eluent, hexane/AcOEtꢀ30/1. Colorless oil. [a]D20 ꢁ21.8 (cꢀ1.16, CHCl3).
77% ee (OD-H, hexane/i-PrOHꢀ100/1, 0.5 ml/min, 254 nm; major
33.1 min, minor 25.0 min). 1H-NMR d: 0.74 (d, Jꢀ6.7, 3H), 0.93 (d, Jꢀ6.7,
3H), 1.82 (m, 1H), 1.99 (s, 3H), 2.75—2.80 (m, 2H), 2.89 (m, 1H), 3.79 (s,
3H), 6.69—6.75 (m, 3H), 7.19 (dd, Jꢀ8.0, 8.0, 1H). 13C-NMR d: 20.3, 20.6,
30.5, 33.2, 47.6, 48.1, 55.1, 111.2, 114.4, 120.7, 129.1, 145.1, 159.5, 208.4.
IR (neat): 1717, 1601. MS m/z: 220 (Mꢂ).
(S)-4-(4-(Trifluoromethyl)phenyl)-5-methylhexan-2-one (8bc) (Entry
5) Eluent, hexane/AcOEtꢀ50/1. Colorless oil. [a]D20 ꢁ9.5 (cꢀ1.12,
CHCl3). 86% ee (AD-H, hexane/i-PrOHꢀ100/1, 0.5 ml/min, 254 nm; major
24.6 min, minor 22.3 min). 1H-NMR d: 0.74 (d, Jꢀ6.8, 3H), 0.93 (d, Jꢀ6.4,
3H), 1.84 (m, 1H), 2.01 (s, 3H), 2.80 (dd, Jꢀ9.5, 16.6, 1H), 2.86 (dd, Jꢀ5.0,
16.6, 1H), 3.02 (m, 1H), 7.26 (d, Jꢀ8.0, 2H), 7.53 (d, Jꢀ8.0, 2H). 13C-NMR
d: 20.2, 20.5, 30.4, 33.0, 47.1, 47.5, 124.3 (q, 1JCFꢀ270), 125.1 (q,
3JCFꢀ3.1), 128.53 (q, 2JCFꢀ31.9), 128.57, 147.8, 207.4. IR (neat): 1717. MS
m/z: 258 (Mꢂ). Anal. Calcd for C14H16F3O: C, 65.10; H, 6.63. Found: C,
64.95; H, 6.63.
(S)-4-(4-Phenylphenyl)-5-methylhexan-2-one (8be) (Entry 6) Eluent,
C6H6/AcOEtꢀ200/1. White solid. mp 66—68 °C. [a]D20 ꢁ19.9 (cꢀ1.07,
CHCl3). 79% ee (OD-H, hexane/i-PrOHꢀ100/1, 0.5 ml/min, 254 nm; major
21.6 min, minor 20.2 min). 1H-NMR d: 0.78 (d, Jꢀ6.7, 3H), 0.95 (d, Jꢀ6.7,
3H), 1.86 (m, 1H), 2.01 (s, 3H), 2.82—2.84 (m, 2H), 2.97 (m, 1H), 7.21 (d,
Jꢀ8.0, 2H), 7.32 (t, Jꢀ7.5, 1H) , 7.42 (dd, Jꢀ7.5, 8.0, 2H) , 7.50 (d, Jꢀ8.0,
2H), 7.57 (d, Jꢀ8.0, 2H). 13C-NMR d: 20.3, 20.6, 30.5, 33.2, 47.5, 47.6,
126.8, 126.9, 127.1, 128.66, 128.7, 139.1, 140.9, 142.4, 208.3. IR (neat):
1717. MS m/z: 266 (Mꢂ). Anal. Calcd for C19H22O: C, 85.67; H, 8.32.
Found: C, 85.57; H, 8.33.
Acknowledgments This research was partially supported by a Grant-in-
Aid for Scientific Research, a Grant-in-Aid for Young Scientists (B), a
Grant-in-Aid for Scientific Research on Priority Areas “Advanced Molecular
Transformations,” and Targeted Proteins Research Program from the Min-
istry of Education, Culture, Sports, Science and Technology of Japan.
References and Notes
1) Tomioka K., Synthesis, 1990, 541—549 (1990).
2) Kanai M., Shibasaki M., “Catalytic Asymmetric Synthesis,” ed. by
Ojima I., VCH, Weinheim, 2000, p. 569.
3) Krause N., Hoffmann-Röder A., Synthesis, 2001, 171—196 (2001).
4) Feringa B. L., Naasz R., Imbos R., Arnold L. A., “Modern Organocop-
per Chemistry,” Chapter 7, ed. by Krause N., Wiley-VCH, Weinheim,
2002.
5) Christoffers J., Koripelly G., Rosiak A., Rössle M., Synthesis, 2007,
1279—1300 (2007).
6) Tomioka K., “Comprehensive Asymmetric Catalysis Supplement to
Chapter 31.1,” ed. by Jacobsen E. N., Pfaltz A., Yamamoto H.,
Springer, New York, 2004, pp. 109—124.
7) Alexakis A., Benhaim C., Eur. J. Org. Chem., 2002, 3221—3236
(2002).
(S)-4-(4-Methoxyphenyl)-4-phenylbutan-2-one (8cd)35) (Entry 7)
Eluent, hexane/AcOEt=20/1. Colorless oil. [a]D20 ꢁ0.72 (cꢀ0.97, CHCl3).
65% ee (OD-H, hexane/i-PrOHꢀ50/1, 1.0 ml/min, 254 nm; major 37.4 min,
minor 44.7 min). 1H-NMR d: 2.07 (s, 3H), 3.14 (d, Jꢀ7.7, 2H), 3.76 (s, 3H),
4.54 (t, Jꢀ7.7, 1H), 6.81 (d, Jꢀ8.9, 2H), 7.12—7.28 (m, 7H). 13C-NMR d:
30.6, 45.2, 49.8, 55.1, 114.0, 126.4, 127.6, 128.6, 128.7, 136.0, 144.2,
158.1, 207.1. IR (nujol): 1709, 1605. MS m/z: 254 (Mꢂ).
8) Alexakis A., Bckvall J. E., Krause N., Pmies O., Diguez M., Chem.
Rev., 108, 2796—2823 (2008).
9) Harutyunyan S. R., den Hartog T., Geurts K., Minnaard A. J., Feringa
B. L., Chem. Rev., 108, 2824—2852 (2008).
10) Our Recent Example: Matsumoto Y., Yamada K., Tomioka K., J. Org.
Chem., 73, 4578—4581 (2008).
11) Review: Hayashi T., Yamasaki K., Chem. Rev., 103, 2829—2844
(2003).
12) Takaya Y., Ogasawara M., Hayashi T., Sakai M., Miyaura N., J. Am.
Chem. Soc., 120, 5579—5580 (1998).
13) Boiteau J.-G., Imbos R., Minnaard A. J., Feringa B. L., Org. Lett., 5,
681—684 (2003).
14) Itooka R., Iguchi Y., Miyaura N., J. Org. Chem., 68, 6000—6004
(2003).
15) Shintani R., Tokunaga N., Doi H., Hayashi T., J. Am. Chem. Soc., 126,
6240—6241 (2004).
16) Shintani R., Duan W.-L., Nagano T., Okada A., Hayashi T., Angew.
Chem., Int. Ed., 44, 4611—4614 (2005).
17) Imamoto T., Sugita K., Yoshida K., J. Am. Chem. Soc., 127, 11934—
11935 (2005).
18) Okamoto K., Hayashi T., Rawal V. H., Org. Lett., 10, 4387—4389
(2008).
19) Kanai M., Koga K., Tomioka K., Tetrahedron Lett., 33, 7193—7196
(1992).
(S)-4-(4-Phenylphenyl)-4-phenylbutan-2-one (8ce) (Entry 8) Eluent,
C6H6/AcOEtꢀ100/1. White solid. mp 117—119 °C. [a]D20 ꢂ6.6 (cꢀ0.96,
CHCl3). 60% ee (OD-H, hexane/i-PrOHꢀ50/1, 1.0 ml/min, 254 nm; major
19.6 min, minor 23.3 min). 1H-NMR d: 2.11 (s, 3H), 3.22 (d, Jꢀ7.3, 2H),
4.64 (t, Jꢀ7.3, 1H), 7.19 (m, 1H), 7.26—7.33 (m, 7H), 7.41 (dd, Jꢀ7.8, 7.8,
2H), 7.50 (d, Jꢀ8.0, 2H), 7.54 (d, Jꢀ7.6, 2H). 13C-NMR d: 30.6, 45.6, 49.6,
126.5, 127.0, 127.1, 127.3, 127.7, 128.1, 128.6, 128.7, 139.3, 140.8, 143.0,
143.8, 206.8. IR (KBr): 1713. MS m/z: 300 (Mꢂ). EI-MS m/z: 300.1504
(Calcd for C22H20O: 300.1514).
(R)-5-Phenylhexan-3-one (8da)36) (Entry 9) Eluent, hexane/AcOEtꢀ
30/1. Colorless oil. [a]D22 ꢁ64.2 (cꢀ1.3, C6H6); lit. [a]D22 ꢁ56.4 (cꢀ1.0,
C6H6) for R. 72% ee (AD-H, hexane/i-PrOHꢀ100/1, 0.5 ml/min, 254 nm;
1
major 11.8 min, minor 10.6 min). H-NMR d: 0.98 (t, Jꢀ7.4, 3H), 1.26 (d,
Jꢀ7.0, 3H), 2.26—2.38 (m, 2H), 2.63 (dd, Jꢀ8.0, 16.2, 1H), 2.72 (dd,
Jꢀ6.7, 16.2, 1H), 3.32 (m, 1H), 7.17—7.30 (m, 5H). 13C-NMR d: 7.5, 21.8,
35.4, 36.6, 50.7, 126.3, 126.8, 128.5, 146.3, 210.5. IR (neat): 1713. MS m/z:
176 (Mꢂ).
20) Kanai M., Tomioka K., Tetrahedron Lett., 36, 4273—4274 (1995).
21) Kanai M., Nakagawa Y., Tomioka K., Tetrahedron, 55, 3843—3854
(1999).
22) Mori T., Kosaka K., Nakagawa Y., Nagaoka Y., Tomioka K., Tetrahe-
dron: Asymmetry, 9, 3175—3178 (1998).
23) Soeta T., Kuriyama M., Tomioka K., J. Org. Chem., 70, 297—300
(2005).
24) Soeta T., Selim K., Kuriyama M., Tomioka K., Tetrahedron, 63,
6573—6576 (2007).
(R)-5-(4-Phenylphenyl)hexan-3-one (8de) (Entry 10) Eluent, hexane/
AcOEtꢀ20/1. White solid. mp 54—56 °C. [a]D20 ꢁ36.6 (cꢀ1.0, CHCl3).
74% ee (AD-H, hexane/i-PrOHꢀ100/1, 0.5 ml/min, 254 nm; major
1
24.0 min, minor 18.7 min). H-NMR d: 1.00 (t, Jꢀ7.3, 3H), 1.30 (d, Jꢀ6.7,
3H), 2.29—2.40 (m, 2H), 2.67 (dd, Jꢀ8.0, 16.2, 1H), 2.76 (dd, Jꢀ6.7, 16.2,
1H), 3.37 (m, 1H), 7.28 (d, Jꢀ8.0, 2H), 7.33 (t, Jꢀ7.5, 1H), 7.42 (dd,
Jꢀ7.5, 8.0, 2H), 7.52 (d, Jꢀ8.0, 2H), 7.57 (d, Jꢀ8.0, 2H). 13C-NMR d: 7.5,
21.9, 35.0, 36.6, 50.7, 127.0, 127.1, 127.19, 127.21, 128.7, 139.2, 140.9,
145.5, 210.4. IR (neat): 1713. MS m/z: 252 (Mꢂ). Anal. Calcd for C18H20O:
C, 85.67; H, 7.99. Found: C, 85.48; H, 8.00.
25) Soeta T., Selim K., Kuriyama M., Tomioka K., Adv. Synth. Catal., 349,

September 2009
629—635 (2007).
26) Selim K., Soeta T., Yamada K., Tomioka K., Chem. Asian J., 3, 342—
350 (2008).
27) Kuriyama M., Tomioka K., Tetrahedron Lett., 42, 921—923 (2001).
28) Kuriyama M., Nagai K., Yamada K., Miwa Y., Taga T., Tomioka K., J.
Am. Chem. Soc., 124, 8932—8939 (2002).
1027
32) Sakuma S., Sakai M., Itooka R., Miyaura N., J. Org. Chem., 65,
5951—5955 (2000).
33) The first “a” and second “a” of 8aa are derived from the suffixes of 7a
and 5a, respectively.
34) Kuriyama M., Soeta T., Hao X., Chen Q., Tomioka K., J. Am. Chem.
Soc., 126, 8128—8129 (2004).
29) Chen Q., Kuriyama M., Soeta T., Hao X., Yamada K., Tomioka K., 35) Defieber C., Paquin J. F., Serna S., Carreira E. M., Org. Lett., 6,
Org. Lett., 7, 4439—4441 (2005). 3873—3876 (2004).
30) Chen Q., Soeta T., Kuriyama K., Yamada K., Tomioka K., Adv. Synth. 36) Hubertus A., Horst S., Chem. Ber., 123, 829—836 (1990).
Catal., 348, 2604—2608 (2006).
31) Srgel S., Tokunaga N., Sasaki K., Okamoto K., Hayashi T., Org. Lett.,
10, 589—592 (2008).
37) Nudelman N. S., Garcia G. V., J. Org. Chem., 66, 1387—1394 (2001).
38) Leitereg T. J., Cram D. J., J. Am. Chem. Soc., 90, 4011—4018 (1968).