Preparation of enantiomerically pure 2′-substituted 2-diphenylphosphino-1,1′-binaphthyls by reductive cleavage of the carbon-phosphorus bond in a borane complex of 2-diphenylphosphino-2′-diphenylphosphinyl-1,1′-binaphthyl

Article abstract of DOI:10.1021/jo010691x

Reaction of (S)-2′-boranatodiphenylphosphino-2-diphenylphosphinyl-1,1′- binaphthyl (3, borane complex of BINAP monoxide) with an excess of n-butyllithium in THF at -78°C brought about a selective cleavage of the carbon-phosphorus bond between the binaphthyl and diphenylphosphinyl groups to generate the binaphthyllithium 14, the treatment of which with electrophiles MeOD, I₂, and ClSnMe₃ gave, after removal of the borane, the corresponding 2′-substituted 2-diphenylphosphino-1,1′-binaphthyls (E-MOP 9: E = D, I, SnMe₃), without loss of the enantiomeric purity.

Full text of DOI:10.1021/jo010691x

8854
J . Org. Chem. 2001, 66, 8854-8858
P r ep a r a tion of En a n tiom er ica lly P u r e 2′-Su bstitu ted
2-Dip h en ylp h osp h in o-1,1′-bin a p h th yls by Red u ctive Clea va ge of
th e Ca r bon -P h osp h or u s Bon d in a Bor a n e Com p lex of
2-Dip h en ylp h osp h in o-2′-d ip h en ylp h osp h in yl-1,1′-bin a p h th yl
Toyoshi Shimada, Hiroaki Kurushima, Yong-Hwan Cho, and Tamio Hayashi*
Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, J apan
thayashi@kuchem.kyoto-u.ac.jp.
Received J uly 9, 2001
Reaction of (S)-2′-boranatodiphenylphosphino-2-diphenylphosphinyl-1,1′-binaphthyl (3, borane
complex of BINAP monoxide) with an excess of n-butyllithium in THF at -78 °C brought about a
selective cleavage of the carbon-phosphorus bond between the binaphthyl and diphenylphosphinyl
groups to generate the binaphthyllithium 14, the treatment of which with electrophiles MeOD, I2,
and ClSnMe3 gave, after removal of the borane, the corresponding 2′-substituted 2-diphenylphos-
phino-1,1′-binaphthyls (E-MOP 9: E ) D, I, SnMe3), without loss of the enantiomeric purity.
Sch em e 1
In tr od u ction
It has been well documented that enantiomerically
pure phosphines whose chirality is due to an axially
chiral 1,1′-binaphthyl backbone are useful as chiral
ligands for transition metal-catalyzed asymmetric reac-
tions.1,2 One of the most useful chiral phosphine ligands
is 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP),3
which exhibits high enantioselectivity in several types
of asymmetric reactions, including ruthenium-catalyzed
hydrogenation4 and rhodium-catalyzed 1,4-addition of
organoboronic acids.5 We have developed axially chiral
monodentate phosphine ligands, represented by 2-diphe-
nylphosphino-2′-methoxy-1,1′-binaphthyl (MeO-MOP),6,7
for the catalytic asymmetric reactions where bisphos-
phine-metal catalysts cannot be used because of their
low catalytic activity and/or low selectivity toward a
desired reaction pathway. The high efficiency of the MOP
ligands has been demonstrated in palladium-catalyzed
asymmetric hydrosilylation of olefins,8 rhodium-catalyzed
arylation of imines,9 and so on.6,10 The MOP ligands have
an advantage over others in that fine-tuning can be
performed by introducing a desired group at the 2′
position of the 1,1′-binaphthyl skeleton according to the
reaction type. The substituents at the 2′ position have
been introduced in most cases by alkylation of the 2′-
hydroxyl group or by nickel-catalyzed cross-coupling-type
reactions of the 2′-trifluoromethanesulfonyloxy group.7,11
For an extension of the utility of the MOP ligands, we
have made a search for new methods of introducing 2′-
substituents on the 1,1′-binaphthyl. The report by Sey-
ferth12 that the carbon-phosphorus bond in triphen-
ylphosphine oxide is cleaved by treatment with an
alkyllithium to generate phenyllithium and alkyldiphen-
ylphosphine oxide attracted our attention. We studied the
selectivity of this lithiation in phosphine oxide derivatives
of BINAP 1-3 and found that the carbon-phosphorus
bond cleavage takes place selectively between the bi-
naphthyl and diphenylphosphinyl groups generating
2-lithio-1,1′-binaphthyl derivatives, and addition of elec-
trophiles to the lithiated binaphthyls leads to the prepa-
ration of 2′-substituted 2-diphenylphosphino-1,1′-binaph-
thyls (MOP) (Scheme 1). The retention or loss of the
enantiomeric purity during the lithiation was dependent
on the substituents at 2 position. Thus, the racemization
* To whom correspondence should be addressed. Fax: 81-75-753-
3988.
(1) For a pertinent review, see: McCarthy, M.; Guiry, P. J . Tetra-
hedron 2001, 57, 3809.
(2) For reviews on catalytic asymmetric reactions, see: (a) J acobsen,
E.; Pfaltz, A.; Yamamoto, H. Comprehensive Asymmetric Catalysis;
Springer: Berlin, 1999; Vols. 1-3. (b) Takaya, H.; Ohta, T.; Noyori,
R. In Catalytic Asymmetric Synthesis; Ojima, I., Ed.; VCH Publishers:
New York, 1993; Chapter 1. (c) Noyori, R.; Ohkuma, T. Angew. Chem.,
Int. Ed. 2001, 40, 40.
(3) Miyashita, A.; Yasuda, A.; Takaya, H.; Toriumi, K.; Ito, T.;
Souchi, T.; Noyori, R. J . Am. Chem. Soc. 1980, 102, 7932.
(4) Okuma, T.; Noyori, R. In Comprehensive Asymmetric Catalysis;
J acobsen, E., Pfaltz, A., Yamamoto, H., Eds.; Springer: Berlin, 1999;
Vol. 1, Chapter 6.1.
(5) (a) Takaya, Y.; Ogasawara, M.; Hayashi, T.; Sakai, M.; Miyaura,
N. J . Am. Chem. Soc. 1998, 120, 5579. (b) Hayashi, T.; Senda, T.;
Takaya, Y.; Ogasawara, M. J . Am. Chem. Soc. 1999, 121, 11591. (c)
Hayashi, T.; Senda, T.; Ogasawara, M. J . Am. Chem. Soc. 2000, 122,
10716 and references therein.
(6) For a review, see: Hayashi, T. Acc. Chem. Res. 2000, 33, 354.
(7) (a) Uozumi, Y.; Hayashi, T. J . Am. Chem. Soc. 1991, 113, 9887.
(b) Uozumi, Y.; Tanahashi, A.; Lee, S.-Y.; Hayashi, T. J . Org. Chem.
1993, 58, 1945. (c) Uozumi, Y.; Suzuki, N.; Ogiwara, A.; Hayashi, T.
Tetrahedron 1994, 50, 4293.
(9) Hayashi, T.; Ishigedani, M. J . Am. Chem. Soc. 2000, 122, 976.
(10) (a) Hayashi, T.; Iwamura, H.; Uozumi, Y.; Matsumoto, Y.;
Ozawa, F. Synthesis 1994, 526. (b) Hayashi, T.; Iwamura, H.; Naito,
M.; Matsumoto, Y.; Uozumi, Y.; Miki, M.; Yanagi, K. J . Am. Chem.
Soc. 1994, 116, 775. (c) RajanBabu, T. V.; Nomura, N.; J in, J .; Radetich,
B.; Park, H.; Nandi, M. Chem. Eur. J . 1999, 1963. (d) Lloyd-J ones, G.
C.; Stephen, S. C.; Murray, M.; Butts, C. P.; Vyskocil, S.; Kocovsky, P.
Chem. Eur. J . 2000, 4348.
(8) Hayashi, T.; Hirate, S.; Kitayama, K.; Tsuji, H.; Torii, A.;
Uozumi, Y. J . Org. Chem. 2001, 66, 1441 and references therein.
(11) Hayashi, T.; Han, J .-W.; Takeda, A.; Tang, J .; Nohmi, K.;
Mukaide, K.; Tsuji, H.; Uozumi, Y. Adv. Synth. Catal. 2001, 343, 279.
10.1021/jo010691x CCC: $20.00 © 2001 American Chemical Society
Published on Web 12/04/2001

2′-Substituted 2-Diphenylphosphino-1,1′-binaphthyl
J . Org. Chem., Vol. 66, No. 26, 2001 8855
Sch em e 2
Sch em e 3
was fast with the diphenylphosphino group while the
enantiomeric purity was retained with its borane com-
plex. Here we report the preparation of new MOP ligands
through the selective lithiation of the phosphine oxide
derivatives of BINAP.
achiral dinaphthophosphole-type intermediate 8. A quite
similar racemization mechanism has been reported by
Cereghetti in the reaction that proceeds through 6,6′-
dimethyl-2′-lithio-2-diphenylphosphinyl-1,1′-biphenyl.14
Second, the carbon-phosphorus bond cleavage with
n-butyllithium was examined for BINAP monoxide 215
(Scheme 3). Under the same conditions used for BINAP
dioxide 1 (in THF at -78 °C for 3 h), the lithiation
proceeded with higher selectivity to give, after quenching
with methanol-d, 2′-deuterio-2-diphenylphosphino-1,1′-
binaphthyl (D-MOP, 9a ) in 87% yield together with the
corresponding amount of butylphosphine oxide 5. How-
ever, complete loss of the enantiomeric purity was
observed in 9a . Similar to the racemization during the
lithiation of dioxide 1, the formation of phosphole-type
intermediate is considered to be responsible for this
racemization. Thus, the racemization is caused by re-
versible transformation of lithiated binaphthyl 11 to
lithium phosphoranide 12.16,17 An attempt to quench the
reaction of the lithiated mixture with chlorotrimethylsi-
lane resulted in the formation of dinaphthophosphole 1018
(75%) and phenyltrimethylsilane. Interestingly, hydroly-
sis of the lithiated reaction mixture after it was allowed
to stand at room temperature for 1 h did not give any
detectable amount of phosphole 10, leaving a complex
mixture of unidentified compounds. It follows that lithi-
ated binaphthyl 11 is in an equilibrium with phosphole
10 and phenyllithium by way of phosphoranide 12 and
that the addition of chlorotrimethylsilane shifts the
equilibrium by removing the phenyllithium.
Resu lts a n d Discu ssion
First, the dioxide of BINAP (1)13 was allowed to react
with n-butyllithium under several reaction conditions
and the reaction was quenched with methanol-d to see
the lithiated position in the products by the deuterium
incorporation (Scheme 2). It was found that the carbon-
phosphorus bond cleavage with n-butyllithium takes
place at -78 °C and the selectivity of the cleavage
between the binaphthyl moiety and the diphenylphos-
phinyl group is very high. Thus, the reaction of enantio-
merically pure (S)-1 with 4 equiv of n-butyllithium in
THF at -78 °C for 3 h followed by addition of excess
methanol-d at the same temperature gave 46% yield of
2′-deuterio-2-diphenylphosphinyl-1,1′-binaphthyl (4a), 56%
yield of 1-deuteriobutyldiphenylphosphine oxide (5), and
4% yield of 2,2′-dideuterio-1,1′-binaphthyl (6). These
results indicate the selective cleavage of the carbon-
phosphorus bond between the binaphthyl moiety and the
diphenylphosphinyl group generating 2′-lithio-2-diphe-
nylphosphinyl-1,1′-binaphthyl (7) together with butyl-
diphenylphosphine oxide. Other carbon-phosphorus bonds
did not undergo cleavage by n-butyllithium, which is
demonstrated by the absence of 2-diphenylphosphinyl-
2′-butyl(phenyl)phosphinyl-1,1′-binaphthyl in the reac-
tion products. The deuteration on the carbon bonded to
the phosphinyl group in the phosphine oxide 5 has been
reported by Seyferth.12 Unfortunately, the enantiomeric
purity of 4a obtained under the conditions described
above was 75% enantiomeric excess (ee), indicating that
the reaction was accompanied by racemization of the
axially chiral binaphthyl skeleton. The racemization is
ascribed probably to the equilibrium between 7 and an
Finally, we succeeded in the selective cleavage of the
phosphorus-carbon bond without loss of the enantio-
(14) Cereghetti, M.; Arnold, W.; Broger, E. A.; Rageot, A. Tetrahe-
dron Lett. 1996, 37, 5347.
(15) (a) Ozawa, F.; Kubo, A.; Hayashi, T. Chem. Lett. 1992, 2177.
(b) Gladiali, S.; Pulacchini, S.; Fabbri, D.; Manassero, M.; Sansoni, M.
Tetrahedron: Asymmetry 1998, 9, 391. (c) Grushin, V. V. J . Am. Chem.
Soc. 1999, 121, 5831.
(16) Hellwinkel, D. Chem. Ber. 1965, 98, 576.
(17) Desponds, O.; Schlosser, M. J . Organomet. Chem. 1996, 507,
257.
(18) (a) Dore, A.; Fabbri, D.; Gladiali, S.; Lucchi, O. D. J . Chem.
Soc., Chem. Commun. 1993, 1124. (b) Gladiali, S.; Dore, A.; Fabbri,
D. J . Org. Chem. 1994, 59, 6363.
(12) Seyferth, D.; Welch, D. E.; Heeren, J . K. J . Am. Chem. Soc.
1964, 86, 1100.
(13) Takaya, H.; Akutagawa, S.; Noyori, R. Org. Synth. 1989, 67,
20.

8856 J . Org. Chem., Vol. 66, No. 26, 2001
Shimada et al.
Ta ble 1. P r ep a r a tion of New MOP Der iva tives fr om a
Bor a n e Com p lex of BINAP Mon oxid ea
Sch em e 4
20
yieldb (%)
of 13
[R]D of 9
entry
electrophile
% eec
(c in CHCl3)
1d
2
3
MeOD
I2
ClSnMe3
ClSiMe2H
ClSiMe3
ClSiMe3
89 (13a )
57 (13b)
69 (13c)
59 (13d )
14 (13e)
43 (13e)
>99
>99
>99
>99
96
-100.0 (0.76)
-52.5 (0.96)
-21.0 (1.01)
-39.8 (1.00)
-25.2 (0.66)
4
5
6e
77
a
Lithiation was carried out on a 0.10 mmol reaction scale with
4 equiv of n-butyllithium in THF at -78 °C for 3 h. An electrophile
(11 equiv) was added at -78 °C, and the mixture was kept stirring
at -78 °C for 1 h. After the reaction was quenched with methanol
at -78 °C, the mixture was warmed to room temperature.
b
Isolated yield. c Determined by HPLC analysis of phosphine
oxide, obtained by removal of borane in 13 followed by oxidation
(see Experimental Section), with chiral stationary phase columns:
Daicel Chiralcel OD-H (hexane/2-propanol ) 90/10 (entries 1-3)
and hexane/2-propanol ) 98/2 (entry 4)), and AD (hexane/2-
d
propanol ) 90/10 (entries 5 and 6)). As an electrophile, metha-
nol-d (25 equiv) was added at -78 °C, and the mixture was
warmed to room temperature after it was stirred at -78 °C for 1
h. e After the addition of chlorotrimethylsilane as an electrophile
at -78 °C, the mixture was immediately warmed to room tem-
perature.
meric purity by using the borane complex of BINAP
monoxide 3, which is readily accessible by treatment of
BINAP monoxide 2 with borane in THF.19 Thus, the
reaction of (S)-3 (>99% ee) with butyllithium at -78 °C
followed by treatment of the resulting lithiated binaph-
thyl with methanol-d gave 89% yield of the borane
complex of D-MOP 13a whose enantiomeric purity is
>99% ee (Scheme 4). The retention of the axial chirality
of the binaphthyl skeleton is ascribed to the coordination
of the diphenylphosphino group to borane, which retards
the intramolecular attack of the naphthyllithium on the
neighboring phosphorus atom in 14 forming a phos-
phacyclopentadiene derivative. The borane in 13a was
readily removed19 by treatment with diethylamine to give
enantiomerically pure D-MOP (9a ).
The present reaction of borane complex 3 opens a new
route to the preparation of 2′-substituted MOP ligands
starting from BINAP. The reaction of the lithiated
binaphthyl 14, generated by the lithiation of 3, with
iodine and chlorotrimethylstannane gave, after removal
of borane, enantiomerically pure (>99% ee) 2-diphen-
ylphosphino-1,1′-binaphthyls 9b and 9c, which contain
an iodo and a trimethylstannyl group, respectively, at
the 2′-position (entries 2 and 3 in Table 1). Unfortunately,
less reactive electrophiles cannot be used in the present
reaction. For example, the reaction with chlorotrimeth-
ylsilane is very slow at -78 °C giving only a low yield of
2′-trimethylsilyl binaphthyl 9e (entry 5), though the
reaction with chlorodimethylhydrosilane gave a higher
yield of the corresponding silylation product 9d (entry
4). The reaction with chlorotrimethylsilane at higher
temperatures was accompanied by racemization to some
extent (entry 6), indicating that the retention of the
enantiomeric purity is realized only at the low temper-
ature even with the borane complex 3.
lithiated binaphthyl with electrophiles provides a new
method for the introduction of new substituents at the
2′-position of MOP ligands. The MOP derivatives sub-
stituted with an iodo and a stannyl group obtained here
are useful intermediates for further transformation into
new MOP ligands, for example, by palladium- or nickel-
catalyzed cross-coupling-type reactions.20
Exp er im en ta l Section
Gen er a l. All moisture sensitive manipulations were carried
out under a nitrogen atmosphere. Nitrogen gas was dried by
passage through P2O5. Optical rotations were recorded with a
J ASCO DIP-370 polarimeter. NMR spectra were recorded on
1
a J EOL J NM LA500 spectrometer (500 MHz for H, 76.5 MHz
for 2H, 125 MHz for 13C, and 202 MHz for 31P in CDCl3).
Chemical shifts are reported in δ parts per million referenced
to an internal SiMe4 standard for 1H NMR, chloroform-d (δ
7.26) for 2H NMR, chloroform-d (δ 77.0) for 13C NMR, and an
external 85% H3PO4 for 31P NMR. High-resolution mass
spectroscopy (HRMS) was recorded with a J EOL J MS-HX110
spectrometer.
Ma ter ia ls. Tetrahydrofuran was distilled from benzophe-
none-ketyl under nitrogen prior to use. BINAP21 and BINAP
monoxide15c were prepared according to the reported proce-
dures.
P r ep a r a tion of (S)-2,2′-Bis(d ip h en ylp h osp h in yl)-1,1′-
bin a p h th yl (BINAP Dioxid e, 1). To a solution of BINAP
(3.11 g, 5.00 mmol) in 150 mL of acetone was added 35%
H2O2aq (10 mL, 103 mmol) at room temperature. The mixture
was stirred at room temperature for 11 h, and a small amount
of manganese(IV) oxide was added. The suspension was stirred
at room temperature for 15 min, before it was filtered and
evaporated. The residue was dissolved in chloroform and
washed with saturated NaHCO3 solution. The organic phase
was dried over anhydrous MgSO4 and evaporated. The crude
product was purified by silica gel column chromatography
In summary, we have found that the carbon-phos-
phorus bond cleavage takes place selectively between the
binaphthyl and diphenylphosphinyl group in the reaction
of phosphine monoxide and dioxide of BINAP with
n-butyllithium and the enantiomeric purity of the bi-
naphthyl axial chirality is retained in the reaction of the
borane complex of BINAP monoxide. The reaction of the
(20) (a) Klunder, J . M.; Posner, G. In Catalytic Organic Synthesis;
Trost, B. M., Fleming, I., Eds.; Pergamon: Oxford, 1991; Vol. 3, Part
1.5, p 227. (b) Farina, V. In Comprehensive Organometallic Chemistry
II; Hegedus, L. S., Ed.; Pergamon: Oxford, 1995; Vol. 12, p 161. (c)
Miyaura, N.; Suzuki, A. Chem. Rev. 1995, 95, 2457. (d) Suzuki, A. J .
Organomet. Chem. 1999, 576, 147. (e) Ogasawara, M.; Hayashi, T. In
Asymmetric Synthesis, 2nd ed.; Ojima, I., Ed.; VCH Publishers: New
York, 2000; Chapter 8F.
(19) (a) Imamoto, T.; Kusumoto, T.; Suzuki, N.; Sato, K. J . Am.
Chem. Soc. 1985, 107, 5301. (b) Oba, G.; Phok, S.; Manuel, G.; Koenig,
M. Tetrahedron. 2000, 56, 121.
(21) Cai, D.; Payack, J . F.; Bender, D. R.; Hughes, D. L.; Verhoeven,
T. R.; Reider, P. J . J . Org. Chem. 1994, 59, 7180.

2′-Substituted 2-Diphenylphosphino-1,1′-binaphthyl
J . Org. Chem., Vol. 66, No. 26, 2001 8857
(acetone) to give BINAP dioxide13 (3.02 g, 92%): [R]25 -388
(b) Ch lor otr im eth ylsila n e a s a n Electr op h ile: The same
procedure described above for treatment of 2 with n-butyl-
lithium was carried out to generate 2′-lithiated MOP 11. To
the reaction mixture containing 11 was added chlorotrimeth-
ylsilane (81 mg, 0.75 mmol) at -78 °C, and the mixture was
allowed to reach room temperature. The mixture was stirred
for 1 h before it was diluted with ether and washed with brine.
The organic phase was dried over anhydrous MgSO4 and
evaporated. The residue was chromatographed on silica gel
(benzene/hexane ) 1/1) to give 21 mg (57% yield) of 7-phenyl-
dinaphtho[2,1-b:1′,2′-d]phosphole18 (10): 1H NMR (CDCl3) δ
7.21 (t, J ) 7.2 Hz, 2H), 7.26-7.34 (m, 3H), 7.50 (t, J ) 8.2
Hz, 2H), 7.55 (t, J ) 7.8 Hz, 2H), 7.78-7.83 (m, 2H), 7.87 (dd,
J ) 8.1, 2.6 Hz, 2H), 7.96 (d, J ) 7.9 Hz, 2H), 8.47 (d, J ) 8.4
Hz, 2H); 31P{1H} NMR δ -4.17 (s).
D
(c 0.53, benzene).
P r ep a r a tion of (S)-2′-Bor a n a tod ip h en ylp h osp h in o-2-
d ip h en ylp h osp h in yl-1,1′-bin a p h th yl (3). To a solution of
BINAP monoxide (919 mg, 1.44 mmol) in 20 mL of THF was
added borane-THF (2.16 mmol) at room temperature. After
the mixture was stirred at room temperature for 2 h, it was
diluted with ethyl acetate and washed with brine. The organic
phase was dried over anhydrous MgSO4 and evaporated to give
BINAP monoxide borane (917 mg, 98%): [R]20D -141.9 (c 1.00,
chloroform); 1H NMR (CDCl3) δ 6.38 (d, J ) 8.5 Hz, 1H), 6.45
(t, J ) 7.6 Hz, 1H), 6.81-6.85 (m, 2H), 7.12 (dt, J ) 7.6, 2.9
Hz, 2H), 7.16-7.30 (m, 9H), 7.36-7.47 (m, 6H), 7.55-7.63 (m,
5H), 7.73-7.77 (m, 3H), 7.82 (d, J ) 8.3 Hz, 1H), 7.85 (dd, J
) 8.7, 2.4, 1H), 7.88 (d, J ) 9.4, 1H); 31P{1H} NMR δ 22.8 (br
s), 27.8 (s); HRMS (FAB) calcd for C44H34OP2B (M - H)+
651.2186, found 651.2180.
R ea ct ion of (S)-2-Bor a n a t od ip h en ylp h osp h in o-2′-d i-
p h en ylp h osp h in yl-1,1′-bin a p h th yl (3) w ith n -Bu tyllith -
iu m . The results are summarized in Table 1. Procedures are
given for the preparation of (R)-2-bor a n a tod ip h en ylp h os-
p h in o-2′-d eu ter io-1,1′-bin a p h th yl (13a ) and (S)-2′-bor a n a -
tod ip h en ylp h osp h in o-2-tr im eth ylsta n n yl-1,1′-bin a p h th -
yl (13c) (entries 1 and 3 in Table 1). To a solution of BINAP
monoxide-borane (3) (65 mg, 0.10 mmol) in 2.5 mL of THF
was added dropwise a solution of n-butyllithium in hexane
(0.25 mL, 0.40 mmol) at -78 °C. The mixture was stirred at
-78 °C for 3 h, and MeOD (0.10 mL, 2.5 mmol) was added.
The mixture was kept stirring at -78 °C for 1 h and allowed
to reach room temperature, diluted with ether, and washed
with brine. The organic phase was dried over anhydrous
MgSO4 and evaporated. The residue was chromatographed on
silica gel (benzene/hexane ) 1/1) to give 40 mg (89% yield) of
(R)-2-boranatodiphenylphosphino-2′-deuterio-1,1′-binaphthyl
(13a ). (R)-2-Bor a n a tod ip h en ylp h osp h in o-2′-d eu ter io-1,1′-
Rea ction of (S)-2,2′-Bis(d ip h en ylp h osp h in yl)-1,1′-bi-
n a p h th yl (1) w ith n -Bu tyllith iu m . To a solution of BINAP
dioxide (1) (66 mg, 0.10 mmol) in 1.0 mL of THF was added
dropwise a solution of n-butyllithium in hexane (0.25 mL, 0.40
mmol) at -78 °C. The mixture was stirred at -78 °C for 3 h,
and MeOD (0.10 mL, 2.5 mmol) was added. The mixture was
kept stirring at -78 °C for 1 h, allowed to reach room
temperature, diluted with ether, and washed with brine. The
organic phase was dried over anhydrous MgSO4 and evapo-
rated. The residue was chromatographed on silica gel (benzene/
ethyl acetate ) 1/1) to give 21 mg (46%) of (R)-2′-deuterio-2-
diphenylphosphinyl-1,1′-binaphthyl (4a ), 14 mg (56%) of
1-deuteriobutyldiphenylphoshine oxide (5), and 1 mg (4%) of
2,2′-dideuterio-1,1′-binaphthyl22 (6). (R)-2′-Deu t er io-2-d i-
1
p h en ylp h osp h in yl-1,1′-bin a p h th yl (4a ): H NMR (CDCl3)
δ 6.89 (d, J ) 8.4 Hz, 1H), 6.93 (dt, J ) 7.6, 2.9 Hz, 2H), 7.04-
7.07 (m, 2H), 7.12 (d, J ) 8.5 Hz, 1H), 7.17-7.35 (m, 8H),
7.50-7.54 (m, 3H), 7.59 (d, J ) 8.0 Hz, 1H), 7.63 (d, J ) 8.3
Hz, 1H), 7.84 (dd, J ) 11.7, 8.6 Hz, 1H), 7.93 (d, J ) 8.2, 1H),
bin a p h th yl (13a ): [R]20 -41.9 (c 1.00, chloroform); 1H NMR
D
(CDCl3) δ 6.97 (d, J ) 8.1 Hz, 1H), 7.02-7.26 (m, 10H), 7.28-
7.33 (m, 3H), 7.39 (d, J ) 10.7 Hz, 1H), 7.41 (d, J ) 10.9 Hz,
1H), 7.52 (t, J ) 7.0 Hz, 1H), 7.67 (d, J ) 8.3 Hz, 1H), 7.66 (t,
J ) 8.2 Hz, 1H), 7.74 (dd, J ) 10.7, 8.7 Hz, 1H), 7.92 (d, J )
8.3 Hz, 1H), 7.96 (d, J ) 7.6 Hz, 1H); 2H NMR (CHCl3) δ 7.20;
31P{1H} NMR δ 23.0 (br s). Anal. Calcd for C32DH25PB: C,
84.78; H + D, 6.00. Found: C, 84.54; H + D, 6.00. (S)-2′-
Bor a n a tod ip h en ylp h osp h in o-2-tr im eth ylsta n n yl-1,1′-bi-
n a p h th yl (13c). A procedure identical to that described above
for treatment of 3 with n-butyllithium was carried out to
generate 2′-lithiated borane complex 14. To the reaction
mixture containing 14 was added chlorotrimethylstannane
(221 mg, 1.1 mmol) as an electrophile at -78 °C, and the
mixture was kept stirring at -78 °C for 1 h. After the reaction
was quenched with methanol (0.10 mL, 2.5 mmol) at -78 °C,
the mixture was warmed to room temperature, diluted with
ether, and washed with brine. The organic phase was dried
over anhydrous MgSO4 and evaporated. The residue was
chromatographed on silica gel (benzene/hexane ) 1/1) to give
42 mg (69% yield) of (S)-2′-boranatodiphenylphosphino-2-
trimethylstannyl-1,1′-binaphthyl (13c). In a similar manner,
borane complexes 13b, d , and e were prepared from 3. (S)-
2′-Bor a n a tod ip h en ylp h osp h in o-2-tr im eth ylsta n n yl-1,1′-
2
7.98 (dd, J ) 8.6, 1.9 Hz, 1H); H NMR (CHCl3) δ 7.50; 31P-
{1H} NMR δ 28.5 (s); HRMS (FAB) calcd for C32DH23OP (M +
H)+ 456.1628, found 456.1628. The enantiomeric purity of 4a
was determined to be 75% by HPLC analysis with Chiralcel
OD-H (hexane/2-propanol ) 90/10). 1-Deu ter iobu tyl(d ip h en -
yl)p h osp h in e Oxid e (5): 1H NMR (CDCl3) δ 0.89 (t, J ) 7.3
Hz, 3H), 1.42 (sextet, J ) 7.4 Hz, 2H), 1.60 (dq, J ) 9.5, 7.4
Hz, 1H), 2.25 (dd, J ) 10.9, 8.6 Hz, 1H), 7.45-7.52 (m, 6H),
7.74 (dd, J ) 11.8, 11.4 Hz, 4H); 2H NMR (CHCl3) δ 2.25; 31P-
{1H} NMR δ 33.2 (s). 2,2′-Did eu ter io-1,1′-bin a p h th yl (6):
1H NMR (CDCl3) δ 7.29 (d, J ) 7.5 Hz, 2H), 7.39 (d, J ) 8.5
Hz, 2H), 7.48 (m, 4H), 7.60 (t, J ) 8.0 Hz, 2H), 7.95 (d, J )
8.0 Hz, 2H), 7.96 (d, J ) 8.1 Hz, 2H); 2H NMR (CHCl3) δ 7.54.
Reaction of (S)-2′-Diph en ylph osph in o-2-diph en ylph os-
ph in yl-1,1′-bin a ph th yl (2) with n -Bu tyllith iu m : (a ) Meth -
a n ol-d a s a n Electr op h ile. To a solution of BINAP monoxide
(2) (64 mg, 0.10 mmol) in 1.0 mL of THF was added dropwise
a solution of n-butyllithium in hexane (0.27 mL, 0.41 mmol)
at -78 °C. The mixture was stirred at -78 °C for 3 h, and
MeOD (50 µL, 1.2 mmol) was added. The mixture was brought
to room temperature, diluted with ether, and washed with
brine. The organic phase was dried over anhydrous MgSO4
and evaporated. The residue was chromatographed on silica
gel (benzene/ethyl acetate ) 1/1) to give 39 mg (87%) of 2′-
deuterio-2-diphenylphosphino-1,1′-binaphthyl (9a). This sample
was determined to be racemic by HPLC analysis of oxide 4a
with Chiralcel OD-H (hexane/2-propanol ) 90/10). 2′-Deu te-
r io-2-d ip h en ylp h osp h in o-1,1′-bin a p h th yl (9a ): 1H NMR
(CDCl3) δ 7.10-7.25 (m, 11H), 7.26-7.31 (m, 3H), 7.34 (dd, J
) 8.5, 2.8 Hz, 1H), 7.39-7.48 (m, 3H), 7.85 (d, J ) 8.6 Hz,
1H), 7.88 (t, J ) 8.3 Hz, 1H), 7.92 (d, J ) 7.9 Hz, 1H), 7.93 (d,
J ) 8.2 Hz, 1H); 2H NMR (CHCl3) δ 7.24; 31P{1H} NMR δ -13.4
(s); HRMS (FAB) calcd for C32DH22P (M)+ 439.1600, found
439.1595. Anal. Calcd for C32DH22P: C, 87.45; H + D, 5.50.
Found: C, 87.25; H + D, 5.78.
bin a p h th yl (13c): [R]D +15.0 (c 0.84, chloroform); 1H NMR
20
(CDCl3) δ -0.24 (s, 9H, J (Sn-CH3 ) 54.8 Hz)), 6.60 (d, J )
8.3 Hz, 1H), 6.67 (dd, J ) 8.3, 7.8 Hz, 1H), 6.92 (dt, J ) 7.8,
2.2 Hz, 2H), 7.07-7.16 (m, 4H), 7.19 (d, J ) 8.5 Hz, 1H), 7.27
(t, J ) 7.6 Hz, 1H), 7.35 (dt, J ) 7.4 Hz, 2H), 7.42 (t, J ) 7.4
Hz, 1H), 7.49-7.59 (m, 5H), 7.63 (d, J ) 8.0 Hz, 1H), 7.72 (d,
J ) 8.0 Hz, 1H), 7.91 (d, J ) 7.9 Hz, 1H), 7.92 (d, J ) 8.6 Hz,
1H); 31P{1H} NMR δ 21.7 (br s); 13C NMR (CDCl3) δ -8.39 (J
(
119Sn-CH3) ) 348.8 Hz, J (117Sn-CH3) ) 333.3 Hz); HRMS
(FAB) calcd for C32H23PB (M - SnMe3 - 2H)+ 449.1636, found
449.1634. (S)-2′-Bor a n a tod ip h en ylp h osp h in o-2-iod o-1,1′-
bin a p h th yl (13b): [R]20D -175.3 (c 1.00, chloroform); 1H NMR
(CDCl3) δ 6.93 (d, J ) 8.5 Hz, 1H), 7.02-7.07 (m, 2H), 7.09
(dt, J ) 7.8, 2.4 Hz, 2H), 7.22-7.25 (m, 3H), 7.28-7.32 (m,
3H), 7.35-7.41 (m, 3H), 7.51-7.56 (m, 3H), 7.67 (dd, J ) 10.1,
9.0 Hz, 1H), 7.70-7.73 (m, 2H), 7.93 (d, J ) 8.3 Hz, 1H), 7.97
(d, J ) 8.8 Hz, 1H); 31P{1H} NMR δ 23.7 (br s); HRMS (FAB)
calcd for C32H23PI (M - BH3 + H)+ 565.0582, found 565.0586.
(22) (a) Forrest, J . J . Chem. Soc. 1960, 566. (b) Hennings, D. D.;
Iwama, T.; Rawal, V. H. Org. Lett. 1999, 1, 1205.

8858 J . Org. Chem., Vol. 66, No. 26, 2001
Shimada et al.
(S)-2′-Bor a n a tod ip h en ylp h osp h in o-2-d im eth ylsilyl-1,1′-
511.2011, found 511.2012. Anal. Calcd for C35H31PSi: C, 83.32;
H, 6.12. Found: C, 81.83; H, 6.43.
bin a p h th yl (13d ): [R]20 -47.4 (c 0.70, chloroform); 1H NMR
D
(CDCl3) δ -0.34 (d, J ) 3.7, 3H), 0.20 (d, J ) 3.7 Hz, 3H),
3.80 (septet, J ) 3.7 Hz, 1H), 6.77 (d, J ) 8.3 Hz, 1H), 6.84
(dd, J ) 8.0, 7.2 Hz, 1H), 7.05-7.09 (m, 3H), 7.21-7.29 (m,
7H), 7.33-7.39 (m, 3H), 7.51 (dd, J ) 7.7, 7.2 Hz, 1H), 7.55
(d, J ) 8.3 Hz, 1H), 7.61 (t, J ) 9.2 Hz, 1H), 7.71 (d, J ) 8.1
Hz, 1H), 7.77 (d, J ) 8.3 Hz, 1H), 7.90 (d, J ) 8.0 Hz, 1H),
7.93 (d, J ) 8.6 Hz, 1H); 31P{1H} NMR δ 22.8 (br s); 13C NMR
(CDCl3) δ -3.73 (Si-CH3), -2.67 (Si-CH3); HRMS (FAB) calcd
for C32H23PB (M - SiMe2H - 2H)+ 449.1636, found 449.1634.
(S)-2-Bor a n a tod ip h en ylp h osp h in o-2′-tr im eth ylsilyl-1,1′-
bin a p h th yl (13e): [R]20D -8.2 (c 1.00, chloroform) for (S)-13e
Oxid a tion of 2′-Su bstitu ted 2-Dip h en ylp h osp h in o-1,1′-
bin a p h th yls (9) w ith m CP BA for th e Deter m in a tion of
En a n tiom er ic P u r ity. A typical procedure is given for the
preparation of (S)-2′-Dip h en ylp h osp h in yl-2-iod o-1,1′-bi-
n a p h th yl (4b). To a solution of 9b (36 mg, 0.063 mmol) in
2.0 mL of CH2Cl2 were added NaHCO3 (9.6 mg, 0.11 mmol)
and mCPBA (17 mg, 0.096 mmol). The suspension was stirred
at room temperature for 2 h and concentrated in vacuo. The
residue was dissolved in ethyl acetate and washed with
saturated NaHCO3 solution. The organic phase was dried over
anhydrous MgSO4 and evaporated. The crude product was
purified by silica gel preparative thin-layer chromatography
(hexane/ethyl acetate ) 1/1) to give 31 mg (85% yield) of 4b:
1H NMR (CDCl3) δ 6.97 (d, J ) 8.4 Hz, 1H), 7.05 (d, J ) 8.4
Hz, 1H), 7.09 (d, J ) 8.5 Hz, 1H), 7.15 (dt, J ) 7.7, 2.9 Hz,
2H), 7.20 (dt, J ) 7.7, 2.9 Hz, 2H), 7.27-7.36 (m, 4H), 7.39-
7.49 (m, 5H), 7.55 (t, J ) 8.0 Hz, 1H), 7.70 (d, J ) 8.2 Hz,
1H), 7.75 (d, J ) 8.7 Hz, 1H), 7.77 (dd, J ) 11.5, 8.6 Hz, 1H),
7.94 (d, J ) 8.0 Hz, 1H), 8.01 (d, J ) 8.7 Hz, 1H); 31P{1H}
NMR δ 28.3 (s); HRMS (FAB) calcd for C32H23OPI (M + H)+
1
of 96% ee; H NMR (CDCl3) δ -0.18 (s, 9H), 6.58 (d, J ) 8.4
Hz, 1H), 6.64 (t, J ) 7.6 Hz, 1H), 6.95 (dt, J ) 7.5, 2.2 Hz,
2H), 7.09 (dd, J ) 10.8, 8.3 Hz, 2H), 7.14-7.19 (m, 3H), 7.26
(m, 1H), 7.36 (m, 2H), 7.43 (t, J ) 7.3 Hz, 1H), 7.47-7.54 (m,
3H), 7.58 (t, J ) 9.4 Hz, 1H), 7.64 (d, J ) 8.1 Hz, 1H), 7.66 (d,
J ) 8.1 Hz, 1H), 7.76 (d, J ) 8.3 Hz, 1H), 7.92 (t, J ) 8.7 Hz,
2H); 31P{1H} NMR δ 22.6 (br s); 13C NMR (CDCl3) δ +0.01
(Si-CH3); HRMS (FAB) calcd for C32H23PB (M - SiMe3 - 2H)+
449.1636, found 449.1634.
581.0531, found 581.0533; [R]20 -110.1 (c 1.04, chloroform).
Rem ova l of Bor a n e fr om 2′-Su bstitu ted Bor a n a to-
d ip h en ylp h osp h in o-1,1′-bin a p h th yls (13). A typical pro-
cedure is given for the preparation of (R)-2′-d eu ter io-2-
d ip h en ylp h osp h in o-1,1′-bin a p h th yl (9a ). To a solution of
borane complex 13a (74 mg, 0.16 mmol) in 5.0 mL of THF was
added diethylamine (0.17 mL, 1.7 mmol) at room temperature,
and the mixture was kept stirring at 40 °C for 1 h. Evaporation
followed by silica gel preparative thin-layer chromatography
(benzene/hexane ) 1/1) of the residue gave 65.1 mg (91% yield)
D
The enantiomeric purity of 4b was determined to be >99% by
HPLC analysis with Chiralcel OD-H (hexane/2-propanol ) 90/
10).
In a similar manner, phosphines 9a , c, and e were oxidized
into the corresponding phosphine oxides 4a , c, and e. In the
reaction of 9d , the hydrosilyl group was oxidized into hydroxy-
silyl during the oxidation of phosphine. The method for the
determination of enantiomeric purity is shown in footnote c
of Table 1. (R)-4a : (>99% ee), [R]20D -16.8 (c 1.00, chloroform).
(S)-2′-Diph en ylph osph in yl-2-tr im eth ylstan n yl-1,1′-bin aph -
th yl (4c): (>99% ee), [R]20D +82.7 (c 1.00, chloroform); 1H NMR
(CDCl3) δ -0.22 (s, 9H, J (Sn-CH3) ) 54.4 Hz)), 6.73-6.76
(m, 3H), 6.92 (t, J ) 8.1 Hz, 2H), 7.06 (dd, J ) 12.0, 8.1 Hz,
2H), 7.16-7.20 (m, 2H), 7.25 (t, J ) 7.6 Hz, 1H), 7.37-7.40
(dt, J ) 7.5, 2.1 Hz, 2H), 7.44 (t, J ) 7.3 Hz, 1H), 7.52-7.58
(m, 4H), 7.64 (dd, 11.7, 8.7 Hz, 1H), 7.72-7.74 (m, 2H), 7.91-
7.93 (m, 2H); 31P{1H} NMR δ 26.8 (s); 13C NMR (CDCl3) δ
-7.96 (J (119Sn-CH3) ) 351.8 Hz, J (117Sn-CH3) ) 336.4 Hz).
Anal. Calcd for C35H31OPSn: C, 68.10; H, 5.06. Found: C,
68.40; H, 5.36. (S)-2-Dip h en ylp h osp h in yl-2′-d im eth ylh y-
of 9a : [R]20 -100.0 (c 0.76, chloroform).
D
In a similar manner, treatment of the borane complex
13b-e with 10 equiv of diethylamine in THF gave a high yield
of the corresponding phosphines 9b-e. (S)-2′-Dip h en ylp h os-
p h in o-2-iod o-1,1′-bin a p h th yl (9b): [R]20 -52.5 (c 0.96,
D
chloroform); 1H NMR (CDCl3) δ 6.70 (d, J ) 8.4 Hz, 1H), 6.83
(t, J ) 7.3 Hz, 1H), 7.01 (t, J ) 7.4 Hz, 2H), 7.07-7.13 (m,
3H), 7.19 (t, J ) 7.3 Hz, 1H), 7.27-7.33 (m, 7H), 7.47-7.51
(m, 2H), 7.68 (d, J ) 8.7 Hz, 1H), 7.82 (d, J ) 8.2 Hz, 1H),
7.91 (t, J ) 8.6 Hz, 2H), 8.06 (d, J ) 8.6 Hz, 1H); 31P{1H} NMR
δ -13.0 (s); HRMS (FAB) calcd for C32H23PI (M + H)+
565.0582, found 565.0583. Anal. Calcd for C32H22PI: C, 68.10;
H, 3.93. Found: C, 68.21; H, 3.75. (S)-2′-Dip h en ylp h os-
ph in o-2-tr im eth ylstan n yl-1,1′-bin aph th yl (9c): [R]20D -21.0
(c 1.01, chloroform); 1H NMR (CDCl3) δ -0.40 (s, 9H, J (119Sn-
CH3) ) 55.6 Hz, J (117Sn-CH3) ) 54.7 Hz)), 6.77 (d, J ) 8.2
Hz, 1H), 6.84 (dd, J ) 8.3, 6.7 Hz, 1H), 6.98 (t, J ) 7.3 Hz,
2H), 7.06 (t, J ) 7.5 Hz, 2H), 7.14 (t, J ) 7.3 Hz, 1H), 7.23-
7.28 (m, 8H), 7.46 (ddd, J ) 8.0, 5.1, 2.5 Hz, 1H), 7.54 (dd, J
) 8.5, 2.7 Hz, 1H), 7.74 (d, J ) 6.7 Hz, 1H), 7.80 (d, J ) 8.2
Hz, 1H), 7.87-7.93 (m, 3H); 31P{1H} NMR δ -14.8 (s); 13C
NMR (CDCl3) δ -8.79 (J (119Sn-CH3) ) 347.1 Hz, J (117Sn-
CH3) ) 330.6 Hz). Anal. Calcd for C35H31PSn: C, 69.91; H,
5.20. Found: C, 70.19; H, 5.39. (S)-2-Dip h en ylp h osp h in o-
20
d r oxysilyl-1,1′-bin a p h th yl (4d ): (>99% ee), [R]D +33.5 (c
1
0.67, chloroform); H NMR (CDCl3) δ -0.85 (s, 3H), 0.46 (s,
3H), 6.63 (d, J ) 8.6 Hz, 1H), 6.68 (dt, J ) 7.7, 3.1 Hz, 2H),
6.85 (t, J ) 8.1 Hz, 1H), 6.89 (t, J ) 7.5 Hz, 1H), 7.03 (dd, J
) 12.3, 7.1 Hz, 2H), 7.09 (d, J ) 8.6 Hz, 1H), 7.19 (t, J ) 7.8
Hz, 1H), 7.23 (t, J ) 8.3 Hz, 1H), 7.47-7.54 (m, 6H), 7.66 (d,
J ) 8.3 Hz, 1H), 7.80 (d, J ) 8.3 Hz, 1H), 7.85 (dd, J ) 11.4,
7.0 Hz, 2H), 7.91 (d, J ) 8.3 Hz, 1H), 7.94 (dd, J ) 8.8, 2.2 Hz,
1H); 31P{1H} NMR δ 30.2 (s); 13C NMR (CDCl3) δ 0.26 (Si-
CH3), 0.92 (Si-CH3); HRMS (FAB) calcd for C34H30O2PSi (M
+ H)+ 529.1753, found 529.1747. (S)-2-Dip h en ylp h osp h in yl-
2′-tr im eth ylsilyl-1,1′-bin a p h th yl (4e): 96% ee; [R]20D +45.6
1
2′-d im eth ylsilyl-1,1′-bin a p h th yl (9d ): [R]20 -39.8 (c 1.00,
(c 1.00, chloroform); H NMR (CDCl3) δ -0.17 (s, 9H), 6.74-
D
chloroform); 1H NMR (CDCl3) δ -0.28 (d, J ) 3.7, 3H), -0.03
(d, J ) 3.7, 3H), 3.73 (septet, J ) 3.7 Hz, 1H), 6.77 (d, J ) 8.6
Hz, 1H), 6.87 (t, J ) 8.6 Hz, 1H), 6.97 (t, J ) 7.6 Hz, 2H), 7.07
(t, J ) 7.3 Hz, 2H), 7.14-7.19 (m, 2H), 7.21-7.32 (m, 7H),
7.44-7.50 (m, 2H), 7.73 (d, J ) 8.3 Hz, 1H), 7.83 (d, J ) 8.1
Hz, 1H), 7.88 (d, J ) 8.5 Hz, 1H), 7.89 (d, J ) 8.4 Hz, 1H),
7.96 (d, J ) 8.2 Hz, 1H); 31P{1H} NMR δ -14.8 (s); 13C NMR
(CDCl3) δ -3.86 (Si-CH3), -3.00 (Si-CH3); HRMS (FAB) calcd
for C34H30PSi (M + H)+ 497.1854, found 497.1853. Anal. Calcd
for C34H29PSi: C, 82.22; H, 5.89. Found: C, 82.03; H, 6.01.
(S)-2-Dip h en ylp h osp h in o-2′-t r im et h ylsilyl-1,1′-b in a p h -
6.78 (m, 3H), 6.90 (t, J ) 7.7 Hz, 1H), 6.95 (t, J ) 7.7 Hz, 1H),
7.02 (dd, J ) 12.1, 7.9 Hz, 2H), 7.14 (d, J ) 8.7 Hz, 1H), 7.20
(t, J ) 8.0 Hz, 1H), 7.25 (t, J ) 7.6 Hz, 1H), 7.40 (ddd, J )
7.9, 7.4, 2.7 Hz, 2H), 7.47 (t, J ) 8.0 Hz, 1H), 7.53 (dd, J )
7.7, 7.1 Hz, 1H), 7.55 (d, J ) 8.2 Hz, 1H), 7.61 (s, 2H), 7.67
(dd, J ) 11.7, 8.8 Hz, 1H), 7.72 (dd, J ) 11.3, 7.7 Hz, 2H),
7.91 (d, J ) 8.4 Hz, 1H), 7.94 (dd, J ) 8.7, 2.1 Hz, 1H); 31P-
{1H} NMR δ 27.1 (s); 13C NMR (CDCl3) δ -0.05 (Si-CH3);
HRMS (FAB) calcd for C35H32OPSi (M + H)+ 527.1960, found
527.1964.
th yl (9e): [R]20 -25.2 (c 0.66, chloroform) for (S)-9e of 96%
Ack n ow led gm en t. This work was supported by the
“Research for the Future” Program, the J apan Society
for the Promotion of Science, and a Grant-in-Aid for
Scientific Research, the Ministry of Education, J apan.
We thank Professor Atsuhiro Osuka and Mr. Hiromitsu
Maeda for obtaining the HRMS data.
D
ee; 1H NMR (CDCl3) δ -0.30 (s, 9H), 6.65 (d, J ) 8.4 Hz, 1H),
6.74 (t, J ) 8.4 Hz, 1H), 6.94 (d, J ) 7.7 Hz, 2H), 7.05 (t, J )
7.0 Hz, 2H), 7.03-7.06 (m, 2H), 7.14 (t, J ) 7.3 Hz, 1H), 7.21-
7.29 (m, 8H), 7.45-7.48 (m, 1H), 7.53 (dd, J ) 8.6, 2.6 Hz,
1H), 7.78-7.80 (m, 2H), 7.88 (t, J ) 8.3 Hz, 2H), 7.94 (d, J )
8.3 Hz, 1H); 31P{1H} NMR δ (s) -15.3 (s); 13C NMR (CDCl3) δ
-0.02 (Si-CH3); HRMS (FAB) calcd for C35H32SiP (M + H)+
J O010691X