Enantioselective Synthesis of Alcohol-Functionalized Diphosphanes
solution of DMPP (5; 0.79 g, 0.004 mol) in dichloromethane was
added dropwise to complex (RC)-4 (3.01 g, 0.004 mol) in dichloro-
methane, and the mixture was stirred at room temperature for 8 h.
The reaction mixture was subsequently concentrated and layered
found C 51.9, H 4.7, N 2.2. 31P{1H} NMR (CDCl3): δ = 19.81 (s,
1JPt,P = 4243.6 Hz, 1 P) ppm. 1H NMR (CDCl3): δ = 1.95 (d, 2JH,H
= 6.4 Hz, 3 H, CHMe), 2.85 (d, JP,H = 0.8 Hz, 3 H, NMe), 3.18
3
3
3
(d, JP,H = 1.3 Hz, NMe), 4.09 (m, 2 H, CH2OH), 4.61 (qn, JH,H
3
with n-hexanes to yield yellow crystals (2.98 g, 79.7 %). [α]D
=
=
4JP,H = 6.4 Hz, 1 H, CHMe), 5.19 (d, JP,H = 17.7 Hz, cis-
PC=CH2), 6.08 (d, JP,H = 36.1 Hz, trans-PC=CH2), 6.68–8.26 (m,
16 H, aromatics) ppm.
3
–147.05 (c = 0.7, CH2Cl2). M.p. 236–238 °C. C42H46ClNO5P2Pt
(937.31): calcd. C 53.8, H 4.9, N 1.5; found C 53.6, H 4.9, N 1.4.
1
3
31P{1H} NMR (CDCl3): δ = 39.62 (d, JPt,P = 3567.4 Hz, JP,P
=
{(R)-1-[1-(Dimethylamino)ethyl]-2-naphthyl-C,N}[(4R,7S)-5,6-dimeth-
yl-7-phenyl-2-(diphenylphosphanyl)-7-phosphabicyclo(2.2.1)hept-5-
en-2-ylmethanol]platinum(II) perchlorate [(RC,SP)-12]: To complex
(RC)-10 (1.50 g, 0.002 mol) in dichloromethane was added silver
perchlorate (0.62 g, 0.003 mol) in distilled water (2 mL), and the
reaction mixture was stirred vigorously at room temperature for
30 min. The crude product was passed through Celite to remove
the AgCl precipitate and subsequently washed with water
1
3
22.8 Hz, 1 P), 115.45 (d, JPt,P = 1580.4 Hz, JP,P = 22.8 Hz, 1 P)
1
ppm. H NMR (CD2Cl2): δ = 1.41 (s, 3 H, C=CMe), 1.86 (s, 3 H,
C=CMe), 1.87 (d, 2JH,H = 6.0 Hz, 3 H, CHMe), 2.51 (s, 3 H, NMe),
2.65 (m, 2 H, Ph2PCCH2), 2.95 (s, 3 H, NMe), 3.18 (m, 2
H,CH2CH2OH), 3.37 (m, 2 H, CH2CH2OH), 3.41 (m, 1 H,
3
4
PhPCH), 3.47 (m, 1 H, PCH), 4.73 (qn, JH,H = JP,H = 6.0 Hz, 1
H, CHMe), 6.64–8.48 (m, 21 H, aromatics) ppm.
Dichlorido[(4R,7S)-5,6-dimethyl-7-phenyl-2-(diphenylphosphanyl)-7- (3ϫ50 mL) and dried with magnesium sulfate. Removal of the sol-
phosphabicyclo(2.2.1)hept-5-en-2-ylethanol]platinum(II) [(SP)-7]: A
solution of (RC,SP)-6 (2.53 g, 0.003 mol) in dichloromethane was
stirred vigorously with concentrated hydrochloric acid (3 mL) for
8 h. The resultant mixture was then washed with water (3ϫ20 mL),
and the organic layer was dried with magnesium sulfate. Upon re-
moval of the solvents a pale-yellow solid was obtained. Recrystalli-
zation from dichloromethane/n-hexanes yielded pale-yellow micro-
crystals (1.88 g, 89.5 %). [α]D = –36.2 (c = 0.4, CH2Cl2). M.p.
vents gave perchlorato (RC)-11 as a yellow solid (1.38 g, 93.8%).
A solution of (RC)-11 (1.35 g, 0.002 mol) in dichloromethane was
treated with DMPP (5; 0.37 g, 0.002 mol). The mixture was allowed
to stir at room temperature for 8 h to yield a yellow solution.
Crystallization from acetonitrile/diethyl ether afforded pale-yellow
needle-like crystals (1.34 g, 81.2%). [α]D = +4.43 (c = 0.3, CH2Cl2).
M.p. 253–245 °C. C41H44ClNO5P2Pt (923.29): calcd. C 53.4, H 4.8,
N 1.5; found C 52.9, H 4.6, N 1.7. 31P{1H} NMR (CDCl3): δ =
42.04 (d, 1JPt,P = 3591.9 ppm, JP,P = 22.8 Hz, 1 P), 117.82 (d, 1JPt,P
288 °C (decomp.). C28H30Cl2OP2Pt (710.48): calcd. C 47.4, H 4.3;
1
found C 47.6, H 4.6. 31P{1H} NMR (CDCl3): δ = 35.59 (d, JPt,P = 1586.1 Hz, JP,P = 19.0 Hz, 1 P) ppm. 1H NMR (CDCl3): δ = 1.42
1
2
= 3435.2 Hz, JP,P = 19.0 Hz, 1 P), 94.96 (d, JPt,P = 3191.9 Hz, JP,P
(s, 3 H, C=CMe), 1.81 (s, 3 H, C=CMe), 1.94 (d, JH,H = 6.0 Hz,
= 19.0 Hz, 1 P) ppm. 1H NMR (CDCl3): δ = 1.27 (s, 3 H, C=CMe),
1.71 (s, 3 H, C=CMe), 2.89 (m, 2 H, Ph2PCCH2), 3.13 (m, 2 H,
3 H, CHMe), 2.55 (s, 3 H, NMe), 2.83 (m, 2 H, Ph2PCCH2), 3.03
(s, 3 H, NMe), 3.67 (m, 2 H, CH2OH), 3.78 (m, 1 H, PCH), 3.95
3
CH2CH2OH), 3.19 (m, 2 H, CH2OH) 3.44 (m, 1 H, PhPCH), 3.52 (m, 1 H, PCH), 4.73 (qn, JH,H
=
4JP,H = 6.4 Hz, 1 H, CHMe),
(m, 1 H, PhPCH), 7.47–8.26 (m, 15 H, aromatics) ppm.
6.66–8.78 (m, 21 H, aromatics) ppm.
Decomplexation of [(4R,7S)-5,6-Dimethyl-7-phenyl-2-(diphenylphos- Dichlorido[(4R,7S)-5,6-dimethyl-7-phenyl-2-(diphenylphosphanyl)-7-
phanyl)-7-phosphabicyclo(2.2.1)hept-5-en-2-ylethanol] [(RP)-8]: A
solution of potassium cyanide (0.45 g, 7.00 mmol) in water (2 mL)
was added to a solution of (SP)-7 (0.05 g, 0.07 mmol) in dichloro-
methane (20 mL), and the mixture was stirred vigorously to ensure
through mixing. The reaction was complete in 4 h. The organic
layer was washed with water (3ϫ5 mL) and then dried with magne-
sium sulfate. A pale-yellow oil (0.018 g, 57.6%) was obtained upon
complete removal of the solvents. [α]D = +38.5 (c = 0.1, CH2Cl2).
phosphabicyclo(2.2.1)hept-5-en-2-ylmethanol]platinum(II) perchlo-
rate [(SP)-13]: A solution of (RC,SP)-12 (1.02 g, 0.001 mol) in
dichloromethane was treated with concentrated hydrochloric acid
(5 mL), and the mixture was allowed to stir vigorously for 8 h at
room temperature. The resultant solution was washed with water
(3ϫ20 mL), and the organic layer was dried with magnesium sul-
fate. Upon filtration and subsequent removal of the solvents a pale-
yellow solid was obtained. Crystallization from dichloromethane/
3
31P{1H} NMR (CDCl3): δ = 35.34 (d, JP,P = 26.5 Hz), 98.46 (d,
n-hexanes yielded pale-yellow prisms (0.7888 g, 91.5 %). [α]D =
3JP,P = 26.5 Hz) ppm.
–24.7 (c = 0.3, CH2Cl2). M.p. 230 °C (decomp.). C27H28Cl2OP2Pt
(696.46): calcd. C 46.6, H 4.0; found C 46.8, H 4.0. 31P{1H} NMR
A solution of the freshly released ligand in dichloromethane
(0.007 g, 0.02 mmol) was added with stirring to a solution of com-
plex (RC)-1 (0.007 g, 0.008 mmol) in dichloromethane and silver
perchlorate (1.86 g, 0.009 mmol) in water (5 mL). The reaction
mixture was stirred at room temperature for 30 min and then
washed with water (3ϫ5 mL) and dried with magnesium sulfate.
The organic layer was dried to obtain a yellow solid. The 31P{1H}
NMR spectrum was identical to that of (RC,SP)-6.
1
(CDCl3): δ = 32.67 (d, JPt,P = 3447.6 Hz, JP,P = 19.0 Hz, 1 P),
1
1
94.52 (d, JPt,P = 3225.9 Hz, JP,P = 19.0 Hz, 1 P) ppm. H NMR
(CD2Cl2): δ = 1.51 (s, 3 H, C=CMe), 1.69 (s, 3 H, C=CMe), 2.91
(m, 2 H, Ph2PCCH2), 3.13 (d, 2 H, CH2OH), 3.43 (m, 1 H,
PhPCH), 3.89 (m, 1 H, PhPCH), 7.52–8.29 (m, 15 H, aromatics)
ppm.
Decomplexation of [(4R,7S)-5,6-Dimethyl-7-phenyl-2-(diphenylphos-
phanyl)-7-phosphabicyclo(2.2.1)hept-5-en-2-yl methanol] [(RP)-14]:
A solution of (SP)-13 in dichloromethane (0.05 g, 0.075 mmol) in
dichloromethane (10 mL) was thoroughly stirred for 3 h with an
excess amount of potassium cyanide (0.24 g, 7.460 mmol) in water
(1 mL). The organic layer was separated, washed with water
(3ϫ10 mL), and dried with magnesium sulfate. Removal of the
solvent left (RP)-14 as a colorless air-sensitive oil (0.018 g, 56.2%).
[α]D = –52.4 (c = 0.1, CH2Cl2). 31P{1H} NMR (CDCl3): δ = 19.21
Chlorido{(R)-1-[1-(dimethylamino)ethyl]-2-naphthyl-C,N}[2-(diphen-
ylphosphanyl)prop-2-en-1-ol]platinum(II) [(RC)-10]: A solution of 9
(1.99 g, 0.008 mol) in dichloromethane (20 mL) was added drop-
wise with stirring to a solution of (RC)-1 (3.5 g, 0.004 mol) in
dichloromethane. The reaction was allowed to stir for 6 h, after
which the solvent was removed under reduced pressure to give the
crude product as a yellow solid. The crude product was purified
by silica-gel column chromatography (dichloromethane/n-hexanes,
3:1; then acetone/dichloromethane, 1:1). Crystallization from
dichloromethane/diethyl ether afforded the pure product as yellow
3
3
(d, JP,P = 113.9 Hz, 1 P), 108.89 (d, JP,P = 113.9 Hz, 1 P) ppm.
A solution of freshly released ligand (RP)-14 (0.005 g, 0.011 mmol)
prisms (1.98 g, 73.9%). [α]D = +55.0 (c = 0.2, CH2Cl2). M.p. 240– in dichloromethane was added to a solution of complex (RC)-1
241 °C. C29H31ClNOPPt (671.08): calcd. C 51.9, H 4.6, N 2.1; (0.005 g, 0.006 mmol) in dichloromethane (10 mL) and silver per-
Eur. J. Inorg. Chem. 2009, 2375–2382
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
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