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Can. J. Chem. Vol. 79, 2001
Ar, 1H), 6.62–7.47 (series of m, Ar, 18H), 7.71–7.85 (series
CH2Cl2 (10 mL) was added. Stirring was continued for
30 min, then the solvent was concentrated and the solid pre-
cipitated was filtered and recrystallized from CH2Cl2–Et2O
of m, Ar, 5H). 31P NMR δ: 42.87.
1
(Sa,S)-20: H NMR δ: 1.43 (d, J = 6.6 Hz, C-CH3, 3H), 2.73
to give 640 mg (91%) of (R)-24, mp 208 to 209°C. [α]D25
=
(s, N-CH3, 3H), 3.04 (d, J = 2.7 Hz, N-CH3, 3H), 4.49 (m,
CH, 1H), 6.08–7.86 (series of m, Ar, 26H). 31P NMR δ:
44.41.
1
+118.9 (c = 0.5, CHCl3). H NMR δ: 1.90 (bs, COD, 2H),
2.35 (bs, COD, 4H), 2.51 (series of m, COD, 2H), 2.54 (s,
CH3, 3H), 4.50 (bs, COD, 2H), 6.10 (d, J = 9.9 Hz, Ar, 1H),
6.65 (bs, COD, 2H), 6.85 (m, Ar, 3H), 7.24 (series of m, Ar,
5H), 7.55 (m, Ar, 6H), 7.69 (m, Ar, 2H), 7.95–8.10 (series
of m, Ar, 5H). 13C NMR δ (aliphatic carbons only): 16.20 (d,
2JC-Rh = 10.2 Hz), 29.4 (s), 32.8 (s). 31P NMR δ: 23.03 (d,
1JP-Rh = 145.8 Hz). Anal. calcd. for C42H37F3O3PS2Rh: C
59.76, H 4.41; found: C 58.97, H 4.54.
Chlorobis-[(S)-N,N-dimethyl(α-methylbenzyl)aminate-2-
C,N][µ-(R,S)-2-(diphenylphosphanyl)-1,1′-binaphthyl-2 ′-
thiolate-P,S,S]dipalladium(II) (21)
To a solution of 2-(diphenylphosphanyl)-1,1′-binaphthyl-
2′-thiol (11) (1.06 g, 2.3 mmol) in CH2Cl2 (10 mL), (–)-di-µ-
chloro-bis[(S)-N,N-dimethyl(α-methylbenzyl)aminate-2-
C,N]dipalladium(II) (1.3 g, 2.3 mmol) and Et3N (8 mL)
were added. The mixture was stirred at room temperature for
10 min. Then 2% HCl was added to neutralize and the or-
ganic phase was separated and washed with water. The or-
ganic layers were dried (Na2SO4) and the solvent
evaporated. The two diastereomeric complexes 21 were iso-
lated in quantitative yield and were separated by flash chro-
matography (n-hexane–tetrahydrofuran, 4:1).
(+)-[(S)-N,N-Dimethyl(α-methylbenzyl)aminate-2-
C,N][(R)-2-(diphenylphosphanyl)-)-2′-methylthio-1,1′-
binaphthalene]palladium(II) ((Ra,S)-22)
To a solution of (–)-di-µ-chloro-bis[(S)-N,N-dimethyl(α-
methylbenzyl)aminate-2-C,N]dipalladium(II)
(226
mg,
0.4 mmol) in CHCl3 (5 mL), a solution of (R)-(+)-2-
(diphenylphosphanyl)-2′-methylthio-1,1′-binaphthalene (R)-
14a (360 mg, 0.8 mmol) in CHCl3 (15 mL) was added. The
mixture was stirred for 30 min, then the solvent was evapo-
rated and the residue was washed with ether. The solid ob-
tained was filtered and crystalized from CH2Cl2–EtO2 to
Less polar isomer (Ra,S,S)-21
1H NMR δ: 0.85 (d, J = 6.6 Hz, C-CH3, 3H), 1.93 (d, J =
6.6 Hz, C-CH3, 3H), 1.94 (m, CH, 1H), 2.16 (s, N-CH3, 3H),
2.28 (s, N-CH3, 3H), 2.96 (s, N-CH3, 3H), 3.14 (d, J =
3.6 Hz, N-CH3, 3H), 3.50 (dq, J = 6.3 Hz, 12 Hz, CH, 1H),
6.01–7.99 (series of m, Ar, 29H), 9.01 (m, Ar, 1H). 13C
NMR δ: aliphatic carbon only 18.21 (s), 33.75 (s), 51.39 (s),
56.17 (d), 56.90 (s), 58.89 (d), 86.42 (d), 86.50 (d). 31P
NMR δ: 40.82.
give 520 mg (89%) of (Ra,S)-22, mp 155–158°C. [α]D25
=
1
+171.4 (c = 0.5, CHCl3). H NMR δ: 1.61 (d, J = 5.4 Hz,
CH3, 3H), 2.15 (s, S-CH3, 3H), 2.68 (bs, N-CH3, 3H), 2.95
(bs, N-CH3, 3H), 3.96 (m, CH, 1H), 5.95 (m, Ar, 1H), 6.15
(m, Ar, 1H), 6.70–7.98 (series of m, Ar, 24H). 13C NMR δ
(aliphatic carbons only): 15.69, 17.28, 44.60, 49.55, 73.87.
31P NMR δ: 48.91. Anal. calcd. for C43H39NPSPdCl: C
66.67, H 5.07, N 1.81; found: C 66.84, H 5.06, N 1.77.
More polar isomer (Sa,S,S)-21
1H NMR δ: 0.57 (d, J = 6.6 Hz, C-CH3, 3H), 1.39 (d, J =
6.6, C-CH3, 3H), 2.64 (d, J = 3.6 Hz, N-CH3, 9H), 3.37 (d,
J = 3.6 Hz, N-CH3, 3H), 3.51 (m, CH, 1H), 4.85 (m, CH,
1H), 6.01–7.99 (series of m, Ar, 29H), 9.01 (m, Ar, 1H). 31P
NMR δ: 41.78.
Hydroformylation of styrene
In a typical experiment, 0.005 mmol of Rh(acac)(CO)2
and 0.02 mmol of 14 (R = i-Pr or Me) were dissolved in
benzene (6 mL) in a Schlenk tube under argon and styrene
(2 mL) was added. The solution was transferred into a
100 mL autoclave and pressurized by CO–H2 = 1:1 mixture
at 60–120 bar. The reaction mixture was agitated by a mag-
netic stirrer in a thermostatted oil bath at the required tem-
perature. At the end of the reaction, the mixture was cooled
to room temperature, vented, and immediately analyzed.
Conversions, chemo-, regio-, and enantioselectivities were
determined by GC analysis: initial temperature: 60°C, heat-
ing rate: 2°C/min; final temperature: 150°C: mesitylene
(20% w/w to the substrate) as an internal standard. Retention
times (min): branched aldehyde: 21 ((S)-isomer), 21.5 ((R)-
isomer); linear aldehyde (min): 26.7.
A solution of (Ra,S,S)-21 (670 mg, 0.66 mmol) in CH2Cl2
(5 mL) was vigorously stirred for 15 min at room tempera-
ture with a solution of ethylenediamine (110 mg, 1.8 mmol)
in water (2.5 mL). The organic phase was separated, washed
with water, and dried (Na2SO4). The solvent was evaporated
and the residue was purified by flash chromatography, using
CH2Cl2 as the eluent, to give 420 mg (88%) of (Ra,S)-20. A
solution of this product (0.93 g, 1.3 mmol) in methanol
(20 mL) containing LiCl (0.51 g, 12 mmol) and two drops of
methansulfonic acid was stirred 10 min at room temperature.
Then, bis(diphenylphosphino)ethane (0.51 g, 1.3 mmol) was
added and stirring was continued for 2 h, while a precipitate
was formed. The solid was filtered and dried to give 610 mg
(99%) of (R)-(+)-11. [α]2D5 = +31.4 (c = 1, CHCl3).
H-transfer reduction of acetophenone
A solution of [Rh(COD)(µ-OMe)]2 (3.3 mg, 0.007 mmol)
and the ligand 14b (7 mg, 0.014 mmol) in i-Pr-OH (11 mL)
containing KOH (0.1 mL, 0.5M in i-Pr-OH) was heated to
reflux under nitrogen for 1 h. A solution of acetophenone
(0.41 mL, 3.5 mmol) in i-Pr-OH (11 mL) was then added to
the resulting yellow solution and heating was continued
while the reaction mixture was monitored by GC. Yield,
conversion, and ee were determined by GC analysis at
(+)-(1,5-Cyclooctadiene)[(R)-2-(diphenylphosphanyl)-2′-
methylthio-1,1′-binaphthalene]rhodium(I)
trifluoromethanesulfonate ((R)-24)
To a solution of [Rh(µ-OMe)(COD)]2 (400 mg, 0.82 mmol)
in CH2Cl2 (5 mL), CF3SO3SiMe3 (184 mg, 0.82 mmol) was
added. The mixture was stirred for 10 min at room tempera-
ture, then a solution of (R)-(+)-2-(diphenylphosphanyl)-2′-
methylthio-1,1′-binaphthalene (422 mg, 0.82 mmol) in
© 2001 NRC Canada