Asymmetric Methoxyselenenylation of Alkenes with Chiral Ferrocenylselenium Reagents

Article abstract of DOI:10.1021/jo970982z

Asymmetric methoxyselenenylation of alkenes was studied using some chiral ferrocenylselenium compounds which were prepared from chiral ferrocenyl-substituted amine, sulfoxide, oxazoline, and pyrrolidine. The highest diastereoselectivity was observed using the chiral amino-substituted ferrocenylserenium triflates in the reaction with trans-β-methylstyrene in an excellent yield. The reaction with silyl enol ethers gave chiral α-seleno ketone with moderate to excellent selectivities. The β,γ-unsaturated ester may be converted into the optically active γ-alkoxy α,β-unsaturated ester using ammonium persulfate in the presence of a catalytic amount of the chiral diferrocenyl diselenide in low optical yields.

Full text of DOI:10.1021/jo970982z

J . Org. Chem. 1997, 62, 7711-7716
7711
Asym m etr ic Meth oxyselen en yla tion of Alk en es w ith Ch ir a l
F er r ocen ylselen iu m Rea gen ts
Shin-ichi Fukuzawa,* Kaoru Takahashi, Hirohisa Kato, and Hiroshi Yamazaki
Department of Applied Chemistry, Chuo University, Kasuga, Bunkyo-ku, Tokyo 112, J apan
Received J une 2, 1997X
Asymmetric methoxyselenenylation of alkenes was studied using some chiral ferrocenylselenium
compounds which were prepared from chiral ferrocenyl-substituted amine, sulfoxide, oxazoline,
and pyrrolidine. The highest diastereoselectivity was observed using the chiral amino-substituted
ferrocenylserenium triflates in the reaction with trans-â-methylstyrene in an excellent yield. The
reaction with silyl enol ethers gave chiral R-seleno ketone with moderate to excellent selectivities.
The â,γ-unsaturated ester may be converted into the optically active γ-alkoxy R,â-unsaturated ester
using ammonium persulfate in the presence of a catalytic amount of the chiral diferrocenyl diselenide
in low optical yields.
In tr od u ction
electrophilic selenium triflate as an electrophile. Several
novel substituted ferrocenes with planar chirality have
been proposed for asymmetric synthesis since our previ-
ous work was reported in 1993.7 We present here the
usefulness of some chiral ferrocenylselenium compounds
derived from chiral ferrocenes, in addition to the previous
amino-substituted ferrocenylselenium compound, as a
chiral inducer in asymmetric methoxyselenenylation.
Organoselenium compounds have become standard
reagents for synthetic organic chemistry,1 and attention
has recently been drawn to their application to asym-
metric synthesis.2 Functionalizations of alkenes with
selenium compounds offer attractive possibilities. One
of the most important of these reaction is methoxysele-
nenylation, and the asymmetric variant of the reaction
has been demonstrated by us3 and other research
groups.4-6 Several chiral selenium compounds have been
designed for asymmetric methoxyselenenylation; how-
ever, most of them have been prepared by multistep
syntheses with low overall yields. We have reported the
highly selective asymmetric methoxyselenenylation with
a ferrocenyl-based chiral selenium compound which can
be easily prepared from a chiral amino-substituted
ferrocene.3a Although this approach to enantiomeric pure
compounds has undoubted value, its utility is hampered
by the low yields of the products. We have improved the
reaction with respect to yield and selectivity using a more
Resu lts a n d Discu ssion
Met h oxyselen en yla t ion w it h Sim p le Alk en es.
Treatment of the chiral ferrocenyl-substituted (R)-amine,8
(S)-sulfoxide,7c (S)-oxazoline,7d and (S)-methoxymeth-
ylpyrrolidine with s-BuLi followed by addition of elemen-
tal selenium, air oxidation, and recrystallization, respec-
tively, afforded the corresponding diastereomerically pure
(R,S;R,S)-diselenide-1,3a (R,S;R,S)-diselenide-2, (S,S;S,S)-
diselenide-3, and (S,S;S,S)-diselenide-4 in 70-80% yields
(Scheme 1). We abbreviate these diselenides as Fa*Se-
SeFa*, Fs*SeSeFs*, Fo*SeSeFo*, and Fp*SeSeFp*, re-
spectively. Fa*SeSeFa* was initially treated with bro-
mine in CH2Cl2 at -78 °C to yield the bromide Fa*SeBr,
which was subsequently allowed to react with silver
triflate or silver tetrafluoroborate to give the more
electrophilic triflate Fa*SeOTf or tetrafluoroborate
Fa*SeBF4. Fa*SeOTf reacted with trans-â-methylsty-
rene at 0 °C for 5 h in the presence of methanol to give
the â-methoxyselenium compound 6 as a single regioi-
somer (attack of methanol at the benzylic carbon) in high
diastereoselectivity (96% de) with an excellent yield
(99%). The diastereomeric excess (% de) in the crude
X Abstract published in Advance ACS Abstracts, October 1, 1997.
(1) For example: Paulmier, C. In Selenium Reagents and Intermedi-
ates in Organic Synthesis; Baldwin, J . E., Ed.; Pergamon Press: Oxford,
1986.
(2) For recent examples: (a) Davis, F. A.; Reddy, R. T. J . Org. Chem.
1992, 57, 2599. (b) Reich, H. J .; Yelm, K. E. J . Org. Chem. 1991, 56,
5672. (c) Komatsu, N.; Nishibayashi, Y.; Sugita, T.; Uemura, S. J .
Chem. Soc., Chem. Commun. 1992, 46. (d) Komatsu, N.; Murakami,
T.; Nishibayashi, Y.; Sugita, T.; Uemura, S. J . Org. Chem. 1993, 58,
3697. (e) Komatsu, N.; Matsunaga, S.; Sugita, T.; Uemura, S. J . Am.
Chem. Soc. 1993, 115, 5847. (f) Komatsu, N.; Nishibayashi, Y.; Uemura,
S. Tetrahedron Lett. 1993, 34, 2339. (g) Nishibayashi, Y.; Singh, J . D.;
Fukuzawa, S.; Uemura, S. J . Org. Chem. 1995, 60, 4114. (h) Fukuzawa,
S.; Tsudzuki, K. Tetrahedron: Asymmetry 1995, 6, 1039. (i) Nishiba-
yashi, Y.; Singh, J . D.; Fukuzawa, S.; Uemura, S. J . Chem. Soc., Perkin
Trans. 1 1995, 2871. (j) Kurose, N.; Takahashi, T.; Koizumi, T. J . Org.
Chem. 1996, 61, 2932. (k) Back, T. G. Dyck, B. P.; Parvez, M. J . Chem.
Soc., Chem. Commun. 1994, 515. (l) Back, T. G. Dyck, B. P.; Parvez,
M. J . Org. Chem. 1995, 60, 703.
(3) (a) Fukuzawa, S.; Kasugahara, Y.; Uemura, S. Tetrahedron Lett.
1994, 35, 9403. (b) Nishibayashi, Y.; Singh, J . D.; Fukuzawa, S.;
Uemura, S. J . Chem. Soc., Chem. Commun. 1994, 1375.
(4) (a) Deziel, R.; Goulet, S.; Grenier, L.; Bordeleau, J .; Bernier, J .
J . Org. Chem. 1993, 58, 3619. (b) Deziel, R.; Malenfant, E.; Belanger,
G. J . Org. Chem. 1996, 61, 1875. (c) Deziel, R.; Malenfant, E.; Belanger,
G. J . Org. Chem. 1995, 60, 4660.
1
adduct was determined by H NMR (400 MHz) integra-
(7) (a) Review: Kagan, H. B.; Diter, P.; Gref, A.; Guillaneux, D.;
Masson-Szymczak, A.; Rebiere, F.; Riant, O.; Samuel, O.; Taudien, S.
Pure Appl. Chem. 1996, 68, 29. (b) Chiral ferrocenyl acetals: Riant,
O.; Samuel, O.; Kagan, H. B. J . Am Chem. Soc. 1993, 115, 5835. (c)
Chiral ferrocenyl sulfoxides: Rebiere, F.; Riant, O.; Ricard, L.; Kagan,
H. B. Angew. Chem., Int. Ed. Engl. 1993, 32, 568. (d) Chiral ferrocenyl
oxazolines: Nishibayashi, Y.; Uemura, S. Synlett 1995, 79. Richards,
C. J .; Damalidis, T.; Hibbs, D. E.; Hursthouse, M. B. Synlett 1995, 75.
Richard, C. J .; Mulvaney, A. W. Tetrahedron: Asymmetry 1996, 7,
1419. Sammakia, T.; Lantham, H. A.; Schaad, R. J . Org. Chem. 1995,
60, 10. Sammakia, T.; Lantham, H. A. J . Org. Chem. 1996, 61, 1629.
Ahn, K. H.; Cho, C.-W.; Baek, H.-H.; Park, J .; Lee, S. J . Org. Chem.
1996, 61, 4937. (e) Chiral ferrocenyl pyrrolidines: Ganter, C.; Wagner,
T. Chem. Ber. 1995, 128, 1157.
(5) (a) Fukita, K.; Murata, K.; Iwaoka, M.; Tomoda, S. Tetrahedron
Lett, 1995, 36, 5219; J . Chem. Soc., Chem. Commun. 1995, 1641.
(b)Tomoda, S.; Iwaoka, M. Chem. Lett. 1988, 1895. (c) Tomoda, S.;
Fujita, K.; Iwaoka, M. J . Chem. Soc., Chem. Commun. 1990, 129. (d)
Iwaoka, M.; Tomoda, K. Heteroatom. Chem. 1995, 6, 247. (e) Fujita,
K.; Iwaoka, M.; Tomoda, S. Chem. Lett. 1994, 923. (f) Tomoda, S.;
Iwaoka, M. J . Chem. Soc., Chem. Comm. 1988, 1283.
(8) (a) Gokel, G.; Ugi, I. J . Chem. Educ. 1972, 49, 294. (b) Mar-
quarding, D.; Klusacek, H.; Gokel, G.; Hoffmann, P.; Ugi, I. J . Am.
Chem. Soc. 1970, 92, 5396.
(6) Wirth, T. Angew. Chem., Int. Ed. Engl. 1995, 34, 1726.
S0022-3263(97)00982-1 CCC: $14.00 © 1997 American Chemical Society

7712 J . Org. Chem., Vol. 62, No. 22, 1997
Fukuzawa et al.
Sch em e 1
Sch em e 3
Ta ble 2. Asym m etr ic Meth oxyselen en yla tion of Alk en es
w ith a Ch ir a l F er r ocen ylselen iu m Tr ifla te (F a *SeOTf)a
entry
alkene
% isolated yield
% deb
Sch em e 2
1
2
3
4
5
6
7
8
9
styrene
97
99
97
99
99
96
96
96
99
96
99
96
35
47
35
15
96
50
96
73
60
96
93
21
o-methylstyrene
m-methylstyrene
R-methylstyrene
trans-â-methylstyrene
cis-2-butenec
trans-2-butenec
cyclopentene
cyclohexene
10
11
12
1-methylcyclohexene
1-phenylcyclohexene
3,3-dimethyl-1-butene
a
Diselenide (0.50 mmol), Br2 (0.60 mmol), AgOTf (1.2 mmol),
b
alkene(2.0 mmol), MeOH (1.0 mL); 0 °C for 5 h. Determined by
1H NMR (400 MHz). c 20 mmol of alkene was used.
Ta ble 1. Asym m etr ic Meth oxyselen en yla tion of
tr a n s-â-Meth ylstyr en e w ith Ch ir a l Selen iu m Com p ou n d s
Der ived fr om Ch ir a l F er r ocen e Der iva tivesa
the reaction of Fa*SeOTf with alkenes are summarized
in Table 2. With styrene and substituted styrenes, the
adducts were obtained as a single regioisomer (Mark-
ovnikov adduct; methanol attacks at the more substituted
carbon) in high yields, but the facial selectivity was lower
than that with â-methylstyrene (entries 1-4). The
selectivity was not improved even if the reaction was
carried out at lower temperature (-78 °C). The reaction
with cis-2-butene gave only 50% de (entry 6), while with
trans-2-butene a high de value (96% de) was obtained
(entry 7). With cyclopentene and cyclohexene, we ob-
tained the trans adduct with moderate de values (60-
73% de) (entries 8-9). On the basis of these results, cis-
alkenes tend to give less diastereoselectivity than that
with trans-alkenes.5d On the other hand, with 1-substi-
tuted cyclohexenes, higher selectivities could be achieved
than with cyclohexene; 1-methylcyclohexene and 1-phe-
nylcyclohexene gave only Markovnikov adducts in 96%
and 93% de, respectively (entries 10-11). These results
suggest that a sterically large group in an alkene is
necessary to achieve a high facial selectivity. However,
the reaction with sterically crowded 3,3-dimethyl-1-
butene afforded the poor selectivity (21% de) (entry 12).
Rea ction Mech a n ism . We confirmed the absolute
configuration of the adduct from methoxyselenenylation
of trans-â-methylstyrene with Fa*SeOTf. Reductive
removal of the chiral organoselenium group of the dia-
stereomeric mixture of the adduct (6) (96% de) by
triphenyltin hydride in refluxing toluene gave methyl
1-phenyl-1-propyl ether (12) in 70% yield (Scheme 4).9
The enantiomeric excess was determined by HPLC
analysis using a chiral column (Daicel, Chiralcel OD
column) compared with authentic samples. The (S)-
configured methyl ether was formed in 96% ee from the
chiral ferrocenyl
or aryl group
% isolated
yield
entry
X
% deb
1
2
3
4
5
6
7
Fa*
Br
20
99
99
99
99
95
99
98
96
89
30
66
56
28
OTf
BF4
OTf
OTf
OTf
OTf
Fs*
Fo*
Fp*
Ph*
a
Diselenide (0.50 mmol), Br2 (0.60 mmol), AgOTf (1.2 mmol),
b
alkene (2.0 mmol), MeOH (1.0 mL); 0 °C for 5 h. Determined by
1H NMR (400 MHz).
tion of the proton of the dimethylamino group and/or the
methoxy group. When compared to those the corre-
sponding bromide, the yields were remarkably increased,
preserving a high diastereoselectivity. Diastereoselec-
tivity of the reaction was as high as that with other recent
chiral selenium compounds.4-6 Fa*SeBF4 gave a some-
what lower diastereoselectivity than the triflate (89% ee).
The diselenides 2, Fs*SeSeFs*, 3, Fo*SeSeFo*, and 4,
Fp*SeSeFp*, similarly converted into the corresponding
selenium triflates, respectively, i.e., Fs*SeOTf, Fo*SeOTf,
and Fp*SeOTf. They underwent methoxyselenenylation
with trans-â-methylstyrene to give the corresponding
adduct (7-9) in 30%, 66%, and 56% de, respectively
(Scheme 2). These results of the reactions with the chiral
electrophilic selenium reagents with trans-â-methylsty-
rene are shown in Table 1. It should be noted that all
diastereoselecivities with these ferrocenylselenium re-
agents were higher than that with chiral (R)-2-(1-
(dimethylamino)ethyl)phenylselenium triflate (5; Ph*Se-
OTf) (Table 1, entry 7).
Fa*SeOTf was revealed to be most effective for high
selectivity; therefore, we applied this compound to vari-
ous alkenes in this reaction (Scheme 3). The results of
(9) Clive D. L. J .; Chittatt, G.; Farina, V.; Kiel, W. A.; Menchen, S.
M.; Russell, C. G.; Singh, A.; Wong, C. K.; Curtis, N. J . J . Am Chem.
Soc. 1980, 102, 4438.

Asymmetric Methoxyselenenylation of Alkenes
J . Org. Chem., Vol. 62, No. 22, 1997 7713
Sch em e 4
Sch em e 6
Sch em e 5
reaction with the (R,S)-chiral ferrocenylselenium reagent.
The enantiomeric excess found was consistent with the
diastereomeric excess in the â-methoxyselenium com-
pound, while the (R)-configured methyl ether was re-
vealed to be formed with the (S,R)-chiral ferrocenylse-
lenium reagent.
The oxidative removal of the selenium moiety by
m-chloroperbenzoic acid (m-CPBA) readily converted 6
into the optically active allyl methyl ether (13) in a good
yield (Scheme 5). The absolute configuration of the major
isomer of 13 was determined as (S) which was consistent
with the above reductive removal result.
Scheme 6 illustrates the possible reaction mechanism
of the reaction. The first step of the reaction involves
the electrophilic attack of the selenium moiety to the
carbon-carbon double bond to form the seleniranium
cation intermediate.5d In this step the diastereoselectiv-
ity should be determined and the two diastereomers (14a
and 14b) would be formed. The second step, ring opening
of the seleniranium cation by MeO-, is not responsible
for the diastereoselectivity. When (R,S)-Fa*SeOTf is
used as an electrophile, 14b is more hindered than 14a ;
steric repulsion between the phenyl and the ferrocenyl
groups in 14b should exist. Thus, the formation of 14a
is more favorable than 14b and then leads to the major
diastereomer of â-methoxyselenium compound (6a ) which
gives methyl (S)-1-phenyl-1-propyl ether (12a ) after
reductive removal of the selenium moiety.
Sch em e 7
Rea ction w ith Silyl En ol Eth er s. Asymmetric
methoxyselenenylation with a silyl enol ether may lead
to a chiral R-seleno ketone.10 The reaction of Fa*SeOTf
with (Z)-1-phenyl-1-(trimethylsiloxy)-1-propene (15) and
methanol yielded the R-ferrocenylseleno ketone 16 in
excellent diastereoselectivity (>99% de) in high yield,
while 1-(trimethylsiloxy)-1-cyclohexene (17) gave the
R-ferrocenylselenocyclohexanone 19 in lower selectivity
(23% de). Replacement of the trimethyl group by a
dimethylphenyl group (18) resulted in almost the same
degree of selectivity (24% de) Scheme 7). These results
were consistent with the diastereselectivities observed
in the reaction with trans-â-methylstyrene and cyclohex-
ene.
Ca ta lytic Asym m etr ic Con ver sion of Alk en es in to
Allylic Eth er s. We finally applied the diselenide 1 to
the catalytic asymmetric oxidation of a â,γ-unsaturated
ester (20-21) and trans-â-methylstyrene into the opti-
cally active allylic ethers.11 The catalytic reaction was
carried out using ammonium persulfate in the presence
of a catalytic amount of Fa*SeSeFa* in alcohol at room
temperature for 7 days. The allyllic ethers (23, R1 ) R2
) Me, or 24, R1 ) R2 ) Et) were produced from 4-phenyl-
3-butenoic acid ester in 17-22% ee with 70-78% yield
(Scheme 8). The reaction with trans-â-methylstyrene
gave the product in only 4% ee with 35% yield although
methoxyselenenylation with the alkene provides excellent
selectivity. Surprisingly, when this catalytic oxidation
was carried out using sulfoxide-substituted diferrocenyl
diselenide (Fs*SeSeFs*) as a catalyst, the vinylic ether
was produced instead of the allylic ether (Scheme 9). The
mechanism for the reaction has not been clarified yet,
but sulfoxide or sulfone may participate in the reaction.
(10) Ryu, I.; Murai, S.; Niwa, I.; Sonoda, N. Synthesis 1977, 874.
(11) Tiecco, M.; Testaferri, L.; Tingoli, M.; Bagnoli, L.; Santi, C. J .
Chem. Soc., Chem. Commun. 1993, 637. Iwaoka, M.; Tomoda, S. J .
Chem. Soc., Chem. Commun. 1992, 1165.

7714 J . Org. Chem., Vol. 62, No. 22, 1997
Fukuzawa et al.
mmol, 70%; IR (KBr) 3055, 2973, 2938, 2861, 2824, 2780, 1738,
Sch em e 8
1585, 1456, 1370, 953, 776 cm-1; [R]25 ) +151.8 (c ) 1.03,
D
1
CHCl3); H NMR (CDCl3) δ 1.35 (d, 3H), 2.26 (s, 6H), 3.78 (q,
1H, J ) 6.7 Hz), 7.1-7.3 (m, 3H), 7.8-7.9 (m, 1H); 13C NMR
δ 14.1, 41.0, 63.6, 125.9, 126.2, 127.6, 131.5, 133.3, 144.1.
Anal. Calcd for C20H28N2Se2: C, 52.87; H, 6.21; N, 6.17.
Found: C, 52.91; H, 6.22; N, 6.14.
Asym m etr ic Meth oxyselen en yla tion of Alk en es w ith
a Ch ir a l Difer r ocen yl Diselen id e. Typical experimental
procedure for the asymmetric methoxyselenenylation of an
alkene is as follows. To a CH2Cl2 solution (2.0 mL) of (R,S)-1
(335 mg, 0.50 mmol) at -78 °C was added a CCl4 (1.0 mL)
solution of bromine (96 mg, 0.60 mmol) slowly over a period
of 20 min. After 30 min, a methanol solution of silver triflate
(308 mg, 1.2 mmol) was added. The resulting heterogeneous
mixture was stirred at -78 °C for 30 min. Then trans-â-
methylstyrene (2.0 mmol) was added to the resulting solution
at -78 °C, and the solution was warmed to 0 °C and stirred
for 5 h. The mixture was treated with an aqueous solution of
NaHCO3, extracted with CH2Cl2 (20 mL × 2), and dried
(K2CO3). Evaporation of the solvent left a dark brown residue
which was subjected to preparative TLC (Al2O3; hexane/ethyl
acetate ) 4/1). A diastereomeric mixture of (R,S)-2-(1-(dim-
ethylamino)ethyl)ferrocenyl 3-methoxy-3-phenyl-2-propyl se-
lenide (6) was obtained as a yellow oil. The diastereomeric
excess was determined by 1H NMR: major diastereomer δ 1.20
(d, 3H, J ) 7.0 Hz), 1.32 (d, 3H, J ) 6.8 Hz), 2.18 (s, 6H), 3.28
(s, 3H), 3.53 (dq, 1H, J ) 3.9, 7.0 Hz), 4.03 (q, 1H, J ) 6.8
Hz), 4.10 (s, 5H), 4.14-4.23 (m, 4H, including CHOCH3), 7.1-
7.3 (m, 5H); 13C NMR δ 9.4, 14.1, 39.8, 44.5, 56.8, 57.4, 67.5,
67.9, 69.8, 70.0, 71.3, 76.3, 84.7, 95.7, 127.0, 127.9, 128.1, 140.4.
Minor diastereomer (distinct signals): 1H NMR δ 2.20 (s,
N(CH3)2), 3.33 (s, OCH3). Anal. Calcd for C24H31NOFeSe: C,
59.50; H, 6.40; N, 2.89. Found: C, 59.22; H, 6.49; N, 2.76.
(R,S)-2-(ter t-Bu tylsu lfin yl)fer r ocen yl 3-Meth oxy-3-ph en -
yl-2-p r op yl Selen id e (7). The title compound was obtained
as a mixture of diastereomers by the reaction of Fs*SeOTf with
trans-â-methylstyrene and methanol. Major diastereomer: 1H
NMR δ 1.25 (s, 9H), 1.37 (d, 3H, J ) 7.1 Hz), 3.32 (s, 3H),
4.3-4.4 (m, 9H including CHOCH3), 7.20-7.50 (m, 5H). Minor
diastereomer (distinct signals): 1H NMR δ 1.30 (s, t-Bu), 1.40
(d, CH3CH, J ) 7.1 Hz), 3.32 (s, OCH3). Anal. Calcd for C24H3-
0FeO2SSe: C, 55.72; H, 5.84. Found: C, 55.88; H, 5.93.
(S,S)-2-(4-Isop r op yl-2-oxa zolin -2-yl)fer r ocen yl 3-Meth -
oxy-3-p h en yl-2-p r op yl Selen id e (8). The title compound
was obtained as a mixture of diastereomers by the reaction of
Fo*SeOTf with trans-â-methylstyrene and methanol. Major
diastereomer: 1H NMR δ 1.01 (d, 3H, J ) 6.9 Hz), 1.07 (d,
3H, J ) 6.8 Hz), 1.26 (d, 3H, J ) 7.1 Hz), 1.88 (oct, 1H J ) 6.6
Hz), 3.31 (s, 3H), 3.4-3.50 (m, 1H), 3.9-4.8 (m, 7H, including
CHOCH3), 4.20 (s, 5H), 7.20-7.40 (m, 5H); 13C NMR δ 15.9,
18.2, 18.8, 32.5, 45.4, 57.6, 69.4, 69.9, 71.0, 71.2, 72.5, 72.6,
74.3, 76.9, 86.5, 126.8, 127.3, 128.1, 140.0, 164.5. Minor
diastereomer (distinct signals): 1H NMR δ 0.94 (d, one of CH3
in CH(CH3)2, J ) 6.8 Hz), 1.02 (d, CH(CH3)2, J ) 6.8 Hz), 1.29
(d, J ) 6.9 Hz, CH3CH), 1.84 (oct, CH(CH3)2, J ) 6.6 Hz), 3.25
(s, OCH3); 13C NMR δ 15.6, 18.0, 18.7, 32.4, 45.1, 57.4, 69.5,
71.2, 72.3, 85.8. Anal. Calcd for C26H31NFeO2Se: C, 59.56;
H, 5.96; N, 2.67. Found: C, 59.88; H, 5.83; N, 2.59.
Sch em e 9
Exp er im en ta l Section
Gen er a l. 1H and 13C NMR spectra were recorded in CDCl3,
and the chemical shifts are reported in δ units downfield from
Me4Si as an internal standard. Gas chromatography analyses
were carried out using a chiral capillary column (G-TA, Asteck,
0.25 mm, 30 m) and helium as the carrier gas. HPLC analyses
were performed on a Dicel Chiralcel OD column (0.46 mm, 25
cm) eluting with 2-propanol/n-hexane (1/9). Elemental analy-
ses were carried out in the Microanalytical Laboratory at Chuo
University.
Ma ter ia ls. The chiral diferrocenyl diselenides (1-4) were
prepared by regioselective o-lithiation of the parent chiral
ferrocenes followed by reaction with elemental selenium
according to the reported method.7
P r ep a r a tion of Diselen id e (2, F s*SeSeF s*). After lithi-
ation of (R)-ferrocenyl tert-butyl sulfoxide (>99% ee) (1.47 g,
2.0 mmol) in tetrahydrofuran with n-butyllithium (2.5 mmol)
at 0 °C under nitrogen, selenium powder (0.24 g, 3.0 mmol)
was added portionwise, and the resulting mixture was stirred
at 0 °C for 15 min and then at room temperature for 3 h. The
mixture was poured into water, and then oxygen was bubbled
through the solution for 1 h at room temperature. [R,S;R,S]-
Bis[2-(tert-butylsulfinyl)ferrocenyl] diselenide (2) was isolated
by column chromatography on silica gel eluted with hexane/
ethyl acetate (1/1): red solid; yield, 1.09 g, 1.48 mmol, 74%;
mp 170-172 °C dec; IR (KBr) 3080, 2958, 1632, 1471, 1362,
1176, 1107, 1030, 822, 572, 508, 475 cm-1; [R]25 ) +1385 (c
D
) 1.0, CHCl3); 1H NMR (CDCl3) δ 1.22 (S, 18H), 4.37 (s, 10H),
4.2-4.8 (m, 6H); 13C NMR δ 23.5, 56.8, 70.0, 70.1, 70.2, 72.3,
75.1, 82.9. Anal. Calcd for C28H34O2S2Se2Fe2: C, 45.67; H,
4.65. Found: C, 45.52 ; H, 4.51.
[S,S;S,S]-Bis[(4-isop r op yl-2-oxa zolin -2-yl)fer r ocen yl]
d iselen id e (3, F o*SeSeF o*): red solid; yield, 1.08 g, 1.44
mmol, 72%; mp 192-194 °C dec; IR (KBr) 2962, 1650, 1457,
1355, 1222, 1209, 1135, 974, 824, 770, 756, 742, 728 cm-1
;
1
[R]25 ) -1186 (c ) 1.0, CHCl3); H NMR (CDCl3) δ 1.03 (d,
D
6H, J ) 6.9 Hz), 1.08 (d, 6H, J ) 6.8 Hz), 1.85 (oct, 2H, J )
6.8 Hz), 4.01-4.09 (m, 2H), 4.18 (s, 10H), 4.1-4.2 (m, 2H),
4.27 (t, 2H, J ) 2.5 Hz), 4.32 (dd, 2H, J ) 8.3, 9.5 Hz), 4.6-
4.7 (m, 4H); 13C NMR δ 18.4, 18.6, 32.6, 69.1, 69.9, 70.0, 71.4,
71.5, 72.4, 73.7, 78.8, 165.2. Anal. Calcd for C32H36N2O2-
Fe2Se2: C, 51.23; H, 4.84; N, 3.73. Found: C,50.98; H, 4.84;
N, 3.81.
(S,S)-2-((2-(Meth oxym eth yl)pyr r olidin -1-yl)m eth yl)fer -
r ocen yl 3-Meth oxy-3-p h en yl-2-p r op yl Selen id e (9). The
title compound was obtained as a mixture of diastereomers
by the reaction of Fp*SeOTf with trans-â-methylstyrene and
methanol. Major diastereomer: 1H NMR (CDCl3) δ 1.5-1.8
(m, 3H), 1.8-2.0 (m, 1H), 1.85 (ddd, 1H, J ) 9.3, 7.3, 2.0 Hz),
2.7-2.8 (m, 1H), 3.01 (ddd, 1H, 8.6, 7.0, 1.7 Hz), 3.28 (dd, 1H,
8.0, 6.9 Hz), 3.25 (s, 3H), 3.35 (s, 3H), 3.53 (dd, 1H, 7.0, 4.7
Hz), 4.06 (s, 10H), 4.2-4.5 (m, 2H); 13C NMR δ 13.4, 22.5, 29.0,
44.4, 54.1, 54.3, 57.6, 58.9, 63.3, 68.2, 69.6, 69.7, 71.4, 72.0,
76.6, 84.0, 88.9, 126.7, 127.0, 127.8, 140.0. Minor diastereomer
(distinct signals): 1H NMR δ 3.40 (s, OCH3); 13C NMR δ 13.6,
45.1. Anal. Calcd for C27H35NFeO2Se: C, 60.00; H, 6.53; N,
2.59. Found: C, 60.18; H, 6.53; N, 2.59.
[S,S;S,S]-Bis[((2-(m eth oxym eth yl)p yr r olid in -1-yl)m e-
th yl)fer r ocen yl]d iselen id e (4, F p *SeSeF p *): orange solid;
yield, 1.14 g, 1.46 mmol, 73%; mp 110-114 °C dec; IR (KBr)
3417, 3096, 3072, 2970, 2926, 2882, 2806, 1633, 1449, 1351,
1121, 999, 816 cm-1; [R]25D ) -312 (c ) 0.49, CHCl3); 1H NMR
(CDCl3) δ 1.5-1.8 (m, 3H), 1.8-2.0 (m, 1H), 1.85 (ddd, 1H, J
) 9.3, 7.3, 2.0 Hz), 2.7-2.8 (m, 1H), 3.01 (ddd, 1H, 8.6, 7.0,
1.7 Hz), 3.28 (dd, 1H, 8.0, 6.9 Hz), 3.41 (s, 3H), 3.53 (dd, 1H,
7.0, 4.7 Hz), 4.06 (s, 10H), 4.2-4.5 (m, 2H); 13C NMR δ 22.6,
28.5, 53.8, 54.1, 59.0, 61.6, 67.8, 67.9, 68.3, 70.0, 70.1, 76.3,
83.8. Anal. Calcd for C34H46N2O2Fe2Se2: C, 52.20; H, 5.67;
N, 3.56. Found: C, 51.97; H, 5.95; N, 3.56.
(R,S)-2-(1-(Dim eth yla m in o)eth yl)p h en yl 3-Meth oxy-3-
p h en yl-2-p r op yl Selen id e (10). The title compound was
obtained as a mixture of diastereomers by the reaction of
(R,R)-Bis[2-(1-(N,N-Dim eth yla m in o)eth yl)p h en yl] d is-
elen id e (5, P h *SeSeP h *): orange oil; yield, 0.64 g, 1.40

Asymmetric Methoxyselenenylation of Alkenes
J . Org. Chem., Vol. 62, No. 22, 1997 7715
Ph*SeOTf with trans-â-methylstyrene and methanol. Major
diastereomer: 1H NMR δ 1.27 (d, 3H, J ) 6.5 Hz), 1.38 (d,
3H, J ) 7.0 Hz), 2.19 (s, 6H), 3.29 (s, 3H), 3.4-3.5 (m, 1H),
3.85 (q, 1H, J ) 6.5 Hz), 4.38 (d, 1H, J ) 4.3 Hz), 7.0-7.5 (m,
9H); 13C NMR δ 16.1, 17.9, 42.5, 45.0, 57.6, 63.3, 86.3, 126.9-
147.0 (several armatic peaks). Minor diastereomer (distinct
signals): 1H NMR δ 1.29 (d, SeCHCH3, J ) 6.5 Hz), 1.33 (d,
CHCH3, J ) 7.0 Hz), 2.21 (s, N(CH3)2), 3.32 (s, OCH3), 3.88
(q, CHN(CH3)2, J ) 6.5 Hz), 4.49 (d, CHOCH3, J ) 4.3 Hz);
(R,S)-2-(1-(Dim eth ylam in o)eth yl)fer r ocen yl 2-Meth oxy-
3,3-d im eth yl-1-bu tyl Selen id e. The title compound was
obtained as a mixture of diastereomers by the reaction of
Fa*SeOTf with 3,3-dimethyl-1-butene and methanol. Major
diastereomer:
1H NMR δ 1.10 (s, 9H), 1.30 (d, 3H, J ) 6.8
Hz), 2.10 (s, 6H), 3.15 (s, 3H), 3.32 (dd, 1H, J ) 3.0, 6.8 Hz),
3.51 (dd, 1H, J ) 3.2, 11.2 Hz), 3.58 (dd, 1H, J ) 6.8, 11.2
Hz), 4.05 (q, 1H, J ) 6.8 Hz), 4.10 (s, 5H), 4.1-4.4 (m, 3H);
13C-NMR major diastereomer δ 9.5, 29.0, 29.3, 34.4, 39.8, 56.8,
57.9, 58.4, 67.6, 68.2, 69.9, 73.4, 75.7, 94.9. Minor diastere-
omer (distinct signals): 1H NMR δ 1.04 (s, C(CH3)3), 1.31 (d,
CHCH3, J ) 6.8 Hz), 2.12 (s, N(CH3)2), 3.06 (dd, CHOCH3),
3.26 (s, OCH3), 3.74 (dd, CHCH2, J ) 6.1, 10.5 Hz), 3.83 (dd,
13C NMR δ 16.0, 18.2, 42.6, 45.2, 63.4. Anal. Calcd for C20
-
H27NOSe: C, 55.57; H, 6.30; N, 3.24. Found: C, 55.75; H, 6.39;
N, 3.20.
(R,S)-2-(1-(Dim eth ylam in o)eth yl)fer r ocen yl 2-Meth oxy-
2-p h en yleth yl Selen id e. The title compound was obtained
as a mixture of diastereomers by the reaction of Fa*SeOTf with
styrene and methanol. Major diastereomer: 1H NMR δ 1.33
(d, 3H, J ) 6.8 Hz), 2.08 (s, 6H), 2.94 (dd, 1H, J ) 8.3, 11.7
Hz), 3.07 (dd, 1H, J ) 4.7, 12.2 Hz), 3.25 (s, 3H), 3.96 (q, 1H,
J ) 6.8 Hz), 4.10 (s, 5H), 4.1-4.4 (m, 4H, including CHOCH3),
7.20-7.40 (m, 5H); 13C NMR δ 11.1, 36.1, 40.0, 56.8, 56.9, 67.5,
69.83, 71.9, 73.0, 75.3, 82.7, 94.5, 126.5, 127.7, 128.3, 141.5.
Minor diastereomer (distinct signals): 1H NMR δ 1.34 (d,
CHCH3, J ) 6.8 Hz), 2.14 (s, N(CH3)2), 2.89 (dd, J ) 5.1, 11.5
Hz, CHSeFa*), 3.24 (s, OCH3), 4.00 (q, CHN(CH3)2, J ) 6.8
Hz); 13C NMR δ 10.9, 83.8, 94.0. Anal. Calcd for C23H29NOFe-
Se: C, 58.74; H, 6.22; N, 2.98. Found: C, 58.51; H, 6.26; N,
2.80.
CHCH2, J ) 3.2, 6.1 Hz), 3.99 (q, CHN(CH3)2, J ) 6.8 Hz); 13
NMR δ 9.6, 35.3, 39.9, 55.4, 59.6, 95.7. Anal. Calcd for C21H33
C
-
NOFeSe: C, 56.00; H, 7.33; N, 3.11. Found: C, 55.99; H, 7.43;
N, 3.02.
tr a n s-(R,S)-2-(1-(Dim et h yla m in o)et h yl)fer r ocen yl 2-
Meth oxycycloh exyl Selen id e. The title compound was
obtained as a mixture of diastereomers by the reaction of
Fa*SeOTf with cyclohexene and methanol. Major diastere-
omer: 1H NMR δ 1.2-2.0 (m, 8H), 1.32 (d, 3H, J ) 6.8 Hz),
2.12 (s, 6H), 3.2-3.3 (m, 2H), 3.29 (s, 3H), 3.96 (q, 1H, J ) 6.8
Hz), 4.09 (s, 5H), 4.2-4.4 (m, 3H); 13C NMR δ 10.3, 22.7, 24.9,
29.0, 29.9, 39.9, 46.4, 55.9, 56.6, 67.6, 67.7, 69.8, 71.9, 76.3,
82.0, 94.7. Minor diastereomer (distinct signals): 1H NMR δ
2.10 (s, N(CH3)2), 3.37 (s, OCH3), 3.98 (q, CHN(CH3)2, J ) 6.8
Hz); 13C NMR δ 10.8, 23.6, 25.5, 30.4, 31.5, 46.1, 56.0, 83.2,
95.2. Anal. Calcd for C21H31NOFeSe: C, 56.25; H, 6.92; N,
3.13. Found: C, 56.06; H, 6.94; N, 3.07.
tr a n s-(R,S)-2-(1-(Dim et h yla m in o)et h yl)fer r ocen yl 2-
Meth yl-2-m eth oxycycloh exyl Selen id e. The title com-
pound was obtained as a mixture of diastereomers by the
reaction of Fa*SeOTf with 1-methyl-1-cyclohexene and metha-
nol. Major diastereomer: 1H NMR δ 1.26 (s, 3H), 1.32 (d, 3H,
J ) 6.9 Hz), 1.3-1.8 (m, 8H), 2.13 (s, 6H), 3.03 (s, 3H), 3.53
(dd, 1H, J ) 2.9, 7.3 Hz), 3.99 (q, 1H, J ) 6.8 Hz), 4.10 (s,
5H), 4.1-4.4 (m, 3H); 13C NMR δ 9.7, 22.1, 22.7, 24.4, 30.6,
34.3, 39.9, 48.2, 51.9, 56.8, 67.3, 69.8, 69.9, 73.2, 76.1, 95.3.
Minor diastereomer (distinct signals): 1H NMR δ 2.11 (s,
N(CH3)2), 3.25 (s, OCH3). Anal. Calcd for C22H33NOFeSe: C,
57.14; H, 7.14; N, 3.03. Found: C, 56.87; H, 7.15; N, 3.04.
tr a n s-(R,S)-2-(1-(Dim et h yla m in o)et h yl)fer r ocen yl 2-
Meth oxy-2-p h en ylcycloh exyl Selen id e. The title com-
pound was obtained as a mixture of diastereomers by the
reaction of Fa*SeOTf with 1-phenyl-1-cyclohexene and metha-
nol. Major diastereomer: 1H NMR δ 1.25 (d, 3H, J ) 6.5 Hz),
1.3-2.6 (m, 8H), 2.13 (s, 6H), 2.81 (s, 3H), 3.74 (t, 1H, J ) 2.4
Hz), 3.90 (s, 5H), 3.9-4.2 (m, 4H, including CHN(CH3)2), 7.2-
7.5 (m, 5H); 13C NMR δ 10.0, 20.9, 22.2, 25.5, 30.2, 39.9, 49.9,
56.1, 56.8, 66.6, 67.2, 69.5, 72.8, 75.4, 80.1, 94.5, 126.8, 127.5,
127.6, 143.8. Minor diastereomer (distinct signals): 1H NMR
δ 1.18 (d, CHCH3, J ) 6.5 Hz), 2.06 (s, N(CH3)2), 2.88 (s,
OCH3); 13C NMR δ 9.9, 21.2, 24.8, 25.0, 39.8, 51.2, 56.5, 78.7.
Anal. Calcd for C27H35NOFeSe: C, 61.83; H, 6.68; N, 2.67.
Found: C, 61.78; H, 6,89; N, 2.53.
tr a n s-(R,S)-2-(1-(Dim et h yla m in o)et h yl)fer r ocen yl 2-
Meth oxycyclop en tyl Selen id e. The title compound was
obtained as a mixture of diastereomers by the reaction of
Fa*SeOTf with cyclopentene and methanol. Major diaster-
eomer: 1H NMR δ 1.32 (d, 3H, J ) 6.8 Hz), 1.5-2.1 (m, 6H),
2.14 (s, 6H), 2.99 (s, 3H), 3.6-3.7 (m, 1H), 3.8-3.9 (m, 1H),
4.02 (q, 1H, J ) 6.8 Hz), 4.08 (s, 5H), 4.2-4.4 (m, 3H); 13C-
NMR δ 9.9, 23.7, 31.1, 31.2, 39.9, 45.8, 56.0, 56.8, 67.7, 67.9,
69.8, 71.8, 75.9, 89.1, 95.3. Minor diastereomer (distinct
signals): 1H NMR δ 2.12 (s, N(CH3)2), 3.22 (s, OCH3), 3.94 (q,
CHN(CH3)2, J ) 6.8 Hz); 13C NMR δ 10.3, 22.9, 31.3, 31.6,
40.0, 46.7, 56.4, 56.7, 87.7, 94.2. Anal. Calcd for C20H29N-
OFeSe: C, 55.30; H, 6.68; N, 3.23. Found: C, 55.06; H, 6,70;
N, 3.13.
er yth r o-(R,S)-2-(1-(Dim et h yla m in o)et h yl)fer r ocen yl
3-Meth oxy-2-bu tyl Selen id e. The title compound was ob-
tained as a mixture of diastereomers by the reaction of
Fa*SeOTf with cis-2-butene and methanol. Major diastere-
omer: 1H NMR δ 1.21 (d, 3H, J ) 6.1 Hz), 1.23 (d, 3H, J ) 7.3
Hz), 1.32 (d, 3H, J ) 6.8 Hz), 2.13 (s, 6H), 3.17 (s, 3H), 3.3-
(R,S)-2-(1-(Dim eth ylam in o)eth yl)fer r ocen yl 2-Meth oxy-
2-o-tolyleth yl Selen id e. The title compound was obtained
as a mixture of diastereomers by the reaction of Fa*SeOTf with
o-methylstyrene and methanol. Major diastereomer: 1H NMR
δ 1.32 (d, 3H, J ) 6.8 Hz), 2.04 (s, 6H), 2.13 (s, 3H), 2.86 (dd,
1H, J ) 9.5, 12.4 Hz), 3.01 (dd, 1H, J ) 3.9, 12.5 Hz), 3.27 (s,
3H), 3.97 (q, 1H, J ) 6.8 Hz), 4.10 (s, 5H), 4.1-4.7 (m, 4H,
including CH OCH3), 7.00-7.40 (m, 4H); 13C NMR δ 11.0, 18.9,
35.2, 40.0, 56.7, 56.9, 67.6, 69.7, 71.9, 73.1, 74.7, 79.6, 94.4,
125.6, 126.0, 127.1, 130.3, 135.4, 139.3. Minor diastereomer
(distinct signals): 1H NMR δ 1.35 (d, CHCH3, J ) 6.8 Hz),
2.12 (s, N(CH3)2), 2.29 (s, o-CH3), 2.92 (dd, CHCH2, J ) 4.7,
11.7 Hz), 3.12 (dd, CHCH2, J ) 9.3, 12.0 Hz), 3.99 (q,
CHN(CH3)2, J ) 6.8 Hz); 13C NMR δ 11.3, 18.7, 35.7, 40.1,
80.1, 93.4. Anal. Calcd for C24H31NOFeSe: C, 59.50; H, 6.40;
N, 2.89. Found: C, 59.15; H, 6.52; N, 2.71.
(R,S)-2-(1-(Dim eth ylam in o)eth yl)fer r ocen yl 2-Meth oxy-
2-m -tolyleth yl Selen id e. The title compound was obtained
as a mixture of diastereomers by the reaction of Fa*SeOTf with
m-methylstyrene and methanol. Major diastereomer: 1H
NMR δ 1.33 (d, 3H, J ) 6.8 Hz), 2.08 (s, 6H), 2.32 (s, 3H),
2.92 (dd, 1H, J ) 9.0, 11.9 Hz), 3.08 (dd, 1H, J ) 4.6, 12.2
Hz), 3.25,(s, 3H), 3.96 (q, 1H, J ) 6.8 Hz), 4.10 (s, 5H), 4.1-
4.4 (m, 4H, including CHOCH3), 7.00-7.30 (m, 4H); 13C NMR
δ 11.1, 21.4, 36.0, 40.1, 56.8, 56.9, 67.4, 72.0, 73.0, 74.9, 82.7,
94.4, 123.6, 127.2, 128.1, 128.3, 137.9, 141.4. Minor diaste-
reomer (distinct signals): 1H NMR δ 1.34 (d, CHCH3, J ) 6.8
Hz), 2.14 (s, N(CH3)2), 2.35 (s, m-CH3), 2.88 (dd, CHCH2, J )
5.1, 11.7 Hz), 3.02 (dd, CHCH2, J ) 9.0, 11.7 Hz), 3.99 (q,
CHN(CH3)2, J ) 6.8 Hz); 13C NMR δ 11.0, 21.3, 36.8, 40.0,
83.8, 93.9. Anal. Calcd for C24H31NOFeSe: C, 59.50; H, 6.40;
N, 2.89. Found: C, 59.37; H, 6.60; N, 2.84.
(R,S)-2-(1-(Dim eth yla m in o)eth yl)fer r ocen yl 2-Meth yl-
2-m eth oxy-2-p h en yleth yl Selen id e. The title compound
was obtained as a mixture of diastereomers by the reaction of
Fa*SeOTf with R-methylstyrene and methanol. Major dias-
tereomer: 1H NMR (CDCl3) δ 1.32 (d, 3H, J ) 6.9 Hz), 1.67
(s, 3H), 2.07 (s, 6H), 3.12 (s, 3H), 3.14 (d, 1H, J ) 12.0 Hz),
3.31 (d, 1H, J ) 8.8 Hz), 3.92 (q, 1H, J ) 6.8 Hz), 4.06 (s, 5H),
4.1-4.2 (m, 3H), 7.2-7.4 (m, 5H); 13C NMR major diastereomer
δ 11.5, 23.9, 40.0, 42.6, 50.8, 56.8, 67.3, 67.5, 69.7, 73.2, 74.8,
78.9, 94.1, 126.2, 127.0, 128.1, 144.3. Minor diastereomer
(distinct signals): 1H NMR δ 1.33 (d, CHCH3, J ) 6.9 Hz),
1.69 (s, CCH3), 2.11 (s, N(CH3)2), 3.11 (s, OCH3), 3.22 (d,
CCH2Se, J ) 11.3 Hz), 3.34 (d, CCH2Se, J ) 9.5 Hz), 3.98 (q,
CHN(CH3)2, J ) 6.8 Hz); 13C NMR δ 11.3, 24.2, 40.1, 42.4,
56.7, 78.8, 94.0. Anal. Calcd for C24H31NOFeSe: C, 59.50;
H, 6.40; N, 2.89. Found: C, 59.26; H, 6,58; N, 2.71.

7716 J . Org. Chem., Vol. 62, No. 22, 1997
Fukuzawa et al.
3.4 (m, 1H), 3.58 (dq, 1H, J ) 3.7, 7.3 Hz), 4.02 (q, 1H, J ) 6.8
Hz), 4.08 (s, 5H), 4.2-4.4 (m, 3H); 13C NMR δ 9.8, 14.5, 16.2,
39.8, 41.3, 56.1, 56.8, 67.5, 67.8, 69.8, 71.5, 75.8, 79.5, 95.3.
Minor diastereomer (distinct signals): 1H NMR δ 1.19 (d,
SeCHCH3, J ) 5.9 Hz), 1.24 (d, CH3OCHCH3, J ) 6.9 Hz),
1.31 (d, CHCH3, J ) 6.8 Hz), 2.11 (s, N(CH3)2), 3.30 (s, OCH3),
3.49 (dq, J ) 1.2, 6.1 Hz), 3.99 (q, CHN(CH3)2, J ) 6.8 Hz);
13C NMR δ 10.2, 14.3, 16.9, 39.9, 43.8, 56.2, 56.7, 80.1, 94.8.
Anal. Calcd for C19H29NOFeSe: C, 54.05; H, 6.92; N, 3.32.
Found: C, 53.87; H, 6,94; N, 3.27.
th r eo-(R,S)-2-(1-(Dim et h yla m in o)et h yl)fer r ocen yl 3-
Meth oxy-2-bu tyl Selen id e. The title compound was ob-
tained as a mixture of diastereomers by the reaction of
Fa*SeOTf with trans-2-butene and methanol. Major dias-
tereomer: 1H NMR δ 1.12 (d, 3H, J ) 6.5 Hz), 1.28 (d, 3H, J
) 6.9 Hz), 1.31 (d, 3H, J ) 6.8 Hz), 2.11 (s, 6H), 3.26 (s, 3H),
3.3-3.4 (m, 2H), 3.99 (q, 1H, J ) 6.8 Hz), 4.10 (s, 5H), 4.2-
4.4 (m, 3H); 13C NMR major diastereomer δ 9.6, 15.8, 16.7,
39.7, 44.5, 56.6, 56.7, 67.4, 67.8, 69.7, 71.7, 76.4, 79.2, 95.2.
Minor diastereomer (distinct signals): 1H NMR δ 1.18 (d,
SeCHCH3, J ) 6.0 Hz), 1.24 (d, CH3OCHCH3, J ) 7.1 Hz),
2.10 (s, N(CH3)2), 3.39 (s, OCH3); 13C NMR δ 17.1, 39.8, 80.4.
Anal. Calcd for C19H29NOFeSe: C, 54.05; H, 6.92; N, 3.32.
Found: C, 54.13; H, 6.98; N, 3.27.
r-(R,S)-2-(((1-(Dim et h yla m in o)et h yl)fer r ocen yl)sel-
en o)p r op iop h en on e (16). The title compound was obtained
as a mixture of diastereomers by the reaction of Fa*SeOTf with
(Z)-1-phenyl-1-(trimethylsiloxy)-1-propene and methanol. Ma-
jor diastereomer: 1H NMR δ 1.25 (d, 3H, J ) 6.8 Hz), 1.54 (d,
3H, J ) 6.8 Hz), 2.21 (s, 6H), 3.51 (br s, 1H), 3.85 (t, 1H, J )
2.5 Hz), 3.93 (s, 5H), 4.05 (q, 1H, J ) 6.8 Hz), 4.15 (br s, 1H),
5.10 (q, 1H, J ) 6.8 Hz), 7.0-7.6 (m, 5H); 13C NMR δ 8.1, 16.2,
39.8, 57.2, 67.6, 68.2, 69.6, 69.8, 71.5, 76.7, 96.0, 127.7, 129.1,
132.1, 136.8, 199.4. Anal. Calcd for C23H27NOFeSe: C, 58.99;
H, 5.81; N, 2.99. Found: C, 58.72; H, 5.89; N, 3.07.
oxidation of alkenes with ammonium persulfate in the pres-
ence of Fa*SeSeFa*. In a 50-mL two-neck round bottom flask
containing a magnetic stirrer bar were placed Fa*SeSeFa* (67
mg, 0.10 mmol) and ammonium persulfate (0.46 g, 2.0 mmol).
A methanol (15 mL) solution of methyl 4-phenyl-3-propenoate
(0.18 g, 1.0 mmol) was added to the flask at room temperature,
and the resulting homogeneous mixture was stirred at this
temperature for 7 days. Water was added to the mixture, and
the aqueous layer was extracted with three portions of diethyl
ether (20 mL) and dried over MgSO4. Evaporation of the
solvent left a pale yellow oil which was subjected to column
chromatography on silica gel; hexane/diethyl ether (10/1)
eluted trans-methyl 4-methoxy-4-phenyl-2-butenoate (23). The
optical purity of the product was determined by GC using a
chiral capillary column (Asteck G-TA, 30 m): 1H NMR (CDCl3)
δ 3.32 (s, 3H), 3.72 (s, 3H), 4.78 (dd, 1H, J ) 1.7, 5.6 Hz), 6.09
(dd, 1H, J ) 1.7, 15.6 Hz), 6.96 (dd, 1H, J ) 5.6, 15.6 Hz),
7.2-7.4 (m, 5H). 13C NMR δ 51.4, 56.6, 82.3, 120.3, 126.9,
128.1, 128.6, 138.7, 147.4, 166.6. Anal. Calcd for C12H14O3:
C, 69.89; H, 6.84. Found: C, 69.54; H, 6.30.
tr a n s-Eth yl 4-eth oxy-4-p h en yl-2-bu ten oa te (24): 1H-
NMR (CDCl3) δ 1.22 (t, 3H, J ) 7.1 Hz), 1.27 (t, 3H, J ) 7.1
Hz), 3.47 (m, 2H), 4.17 (q, 2H, J ) 7.3 Hz), 4.89 (dd, 1H, J )
1.5, 5.3 Hz), 6.08 (dd, 1H, J ) 1.5, 15.6 Hz), 6.97 (dd, 1H, J )
5.3, 15.6 Hz), 7.2-7.4 (m, 5H); 13C NMR δ 14.0, 15.1, 60.3,
64.3, 80.5, 120.6, 126.9, 128.0, 128.5, 139.3, 147.6, 166.2. Anal.
Calcd for C14H18O3: C, 71.77; H, 7.74. Found: C, 71.54; H,
7.30.
Meth yl 4-m eth oxy-4-p h en yl-3-bu ten oa te (26): 1H NMR
(CDCl3) δ 3.34 (d, 2H, J ) 7.1 Hz), 3.52 (s, 3H), 3.72 (s, 3H),
5.41 (t, 1H, J ) 7.1 Hz), 7.2-7.5 (m, 5H); 13C NMR δ 31.1,
51.8, 58.4, 105.2, 126.3, 128.3, 128.4, 135.0, 156.9, 172.5. Anal.
Calcd for C12H14O3: C, 69.89; H, 6.84. Found: C, 69.54; H,
6.30.
(R,S)-2-(1-(Dim eth yla m in o)eth yl)fer r ocen yl 2-Oxa cy-
cloh exyl Selen id e (19). The title compound was obtained
as a mixture of diastereomers by the reaction of Fa*SeOTf with
1-(trimethylsiloxy)-1-cyclohexene and methanol. Major dias-
tereomer: 1H NMR δ 1.27 (d, 3H, J ) 6.8 Hz), 1.4-2.8 (m,
8H), 2.08 (s, 6H), 3.06 (dd, 1H, J ) 6.1, 12.4 Hz), 3,98 (q, 1H,
J ) 6.8 Hz), 4.10 (s, 5H), 4.2-4.4 (m, 3H); 13C NMR major
diastereomer δ 9.0, 24.2, 26.5, 33.2, 37.5, 39.5, 52.6, 56.8, 67.6,
68.2, 69.7, 70.8, 75.7, 94.2, 209.5. Minor diastereomer (distinct
signals): 1H NMR δ 1.31 (d, CHCH3, J ) 6.6 Hz), 2.10 (s,
N(CH3)2), 3.10 (dd, COCHSe, J ) 6.1, 12.5 Hz), 3.96 (q,
CHN(CH3)2, J ) 6.8 Hz); 13C NMR δ 10.1, 22.3, 27.0, 34.7,
38.0, 39.8, 52.7, 56.9, 95.3, 208.2; IR (CHCl3) 1693 cm-1 (CdO).
Anal. Calcd for C20H27NOFeSe: C, 55.57; H, 6.30; N, 3.24.
Found: C, 55.54; H, 6.30; N, 3.24.
Ack n ow led gm en t. This work was financially sup-
ported by The Institute of Science and Engineering,
Chuo University. We thank Professor Sakae Uemura,
Kyoto University, for his useful discussions and com-
ments on this work.
Su p p or tin g In for m a tion Ava ila ble: 1H and 13C NMR
spectra of diferrocenyl diselenides, 2-4, â-methoxyalkyl or
arylferrocenyl selenides, and R-seleno ketones (49 pages). This
material is contained in libraries on microfiche, immediately
follows this article in the microfilm version of the journal, and
can be ordered from the ACS; see any current masthead page
for ordering information.
Ca ta lytic Asym m etr ic Con ver sion of Alk en es in to
Allylic Eth er s. The following is the typical procedure for the
J O970982Z