Diphosphine sulfides derived from 2,2'-biphosphole: Novel chiral S,S ligands for palladium-catalyzed asymmetric allylic substitution

Article abstract of DOI:10.1039/b719554k

Diphosphine sulfides derived from 2,2′-biphosphole have been efficiently synthesized in an enantiomerically pure form by a four step synthetic sequence. These S,S-ligands were used for the first time in Pd-catalyzed asymmetric allylic alkylation. Good yields and enantiomeric excess up to 73% were obtained. The Royal Society of Chemistry.

Full text of DOI:10.1039/b719554k

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PAPER
www.rsc.org/dalton | Dalton Transactions
Diphosphine sulfides derived from 2,2ꢀ-biphosphole: novel chiral S,S ligands
for palladium-catalyzed asymmetric allylic substitution†
Emmanuel Robe´,a Wieslawa Perlikowska,b Ce´line Lemoine,a Lisa Diab,a Sandrine Vincendeau,a
Marian Mikolajczyk,b Jean-Claude Darana and Maryse Gouygou*a
Received 21st December 2007, Accepted 17th March 2008
First published as an Advance Article on the web 24th April 2008
DOI: 10.1039/b719554k
Diphosphine sulfides derived from 2,2ꢀ-biphosphole have been efficiently synthesized in an
enantiomerically pure form by a four step synthetic sequence. These S,S-ligands were used for the first
time in Pd-catalyzed asymmetric allylic alkylation. Good yields and enantiomeric excess up to 73%
were obtained.
the last step, sulfuration of IV led to 2,2-biphosphole disulfides
Introduction
V as a mixture of isomers, with the exception of V·4. Three
The design and synthesis of new and efficient chiral ligands
diastereoisomers have been obtained and separated by column
chromatography in the case of V·1, V·3 and V·5.5 For compounds
play a central role in the development of highly enantiose-
lective transition-metal-catalyzed asymmetric synthesis.1 Chiral
V·2 and V·6, only two diastereoisomers have been isolated in the
phosphorus ligands, in particular C1- and C2-symmetric ligands
pure form by column chromatography.
possessing the axially chiral 1,1ꢀ-binapthyl framework, are among
Owing to X-ray diffraction studies, we could establish the
the most widely used chiral ligands2 In recent years, axially chiral
relative configuration of both central and axial element of
chirality of the 2,2ꢀ-biphosphole framework for the majority of
the compounds obtained.10
sulfur ligands based on binapthalene backbone have proved to
be as useful as other classical asymmetric ligands (e.g. P,S- het-
erodonor ligands),3 but no study has yet devoted to atropoisomeric
diphosphine sulfide ligands (S,S-ligands).
The molecular structure of V·411 is presented in Fig 1 and
selected bond distances and angles in Table 1. Compound V·4
crystallizes in a non centrosymmetric space group (C2). The
refinement of the Flack’s parameter12 (0.00(6)) clearly indicates
that V·4 is enantiomerically pure in the solid state and the abso-
lute configuration is R[Sp,Sp,Rc,Rc] (axial chirality [phosphorus
chirality, carbon chirality]).
C2-Symmetric diphosphine sulfides derived from 2,2ꢀ-
biphosphole, which combine axial chirality and phosphorus
chiralities, belong to the atropos.4 class of ligands since their
axial chiral configurations can be resolved.5 These disulfides are
attractive because different diastereoisomers can be easily ob-
tained by simple sulfuration of the corresponding stereodynamic
diphosphines.6
Here we present a series of diphosphine sulfides V derived
from 2,2ꢀ-biphosphole ligands that are accessible by a four-step
synthetic sequence. The new ligands proved to be active and
selective in palladium catalyzed allylic substitution.
Results and discussion
The synthetic route to obtain the title sulfides derived from 2,2ꢀ-
biphosphole is shown in Scheme 1. In the first step, pyrolysis
of phosphole I7 using the procedure previously described by
F. Mathey et al. gave the tetraphosphole II 8 In the next step,
treatment of compound II with sodium naphthalene led to the 2,2ꢀ-
biphospholyl anion III. Then, the asymmetric alkylation of III 9 in
high dilution conditions could be achieved using enantiomerically
pure diol ditosylates 1, 3 and 5 5 or dimesylates 2, 4 and 6 to afford
the expected 2,2ꢀ-biphospholes IV in good yields (35 to 78%). In
Fig. 1 Molecular view of R[Sp,Sp,Rc,Rc]-V·4 with atom labeling scheme.
Ellipsoids represent 30% probability level.
Palladium catalyzed nucleophilic substitution reactions of al-
lylic substrates constitute a highly useful and versatile method for
C–C bond formation and asymmetric versions of this reaction
have been extensively studied over the last decade.13 Many
homo- and heterodonor chiral bidentate ligands such as N,N-
(e.g. bisoxazolines.14), P,P- (e.g. Trost’s P,P- ligands15), N,P-
(phosphinooxazolines16) have been exploited in such a reaction.
aLaboratoire de Chimie de Coordination, CNRS, 205 Route de Nar-
bonne, F-31007, Toulouse, Cedex, France. E-mail: gouygou@lcc-toulouse.fr;
Fax: +33 (0)5 61 55 30 00; Tel: +33 (0)5 61 33 31 74
bCentre of Molecular and Macromolecular Studies, Polish Academy of
Sciences, 90-363 Ło´dz´, Sienkiewicza 112, Poland
† CCDC reference number 669755. For crystallographic data in CIF
format see DOI: 10.1039/b719554k
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Scheme 1 Synthesis of diphosphine sulfides V.
chloride dimer [Pd(g3-C3H5)Cl]2. The nucleophile was generated
from dimethyl malonate using N,O-bis(trimethylsilyl)acetamide
(BSA) and catalytic quantities of KOAc. The results are listed in
Table 2.
◦
˚
Table 1 Selected bond distances (A), bond angles ( ) and torsion angle
for the compound R[Sp,Sp,Rc,Rc]-V·4.
P(1)–S(1) 1.9430(9)
P(1)–C(1) 1.844(2)
P(2)–S(2) 1.9448(9)
P(2)–C(2) 1.840(2)
All of the ligands V gave palladium catalytic systems that
are active in allylic substitution producing the corresponding
allylic substitution product with an enantiomeric excess in the
range of 18 to 73%. The best result in terms of activities and
enantioselectivities were obtained with ligands R[Sp,Sp,Rc,Rc]-
V·1c (entry 3) and S[Rp,Rp,Rc]-V·6b (entry 11), in which cases the
substitution product was obtained with an enantiomeric excess of
P(1)–C(11) 1.798(2)
P(1)–C(14) 1.814(2)
P(2)–C(21) 1.798(2)
P(2)–C(24) 1.804(2)
C(11)–P(1)–C(14) 92.91(10)
C(11)–P(1)–C(1) 104.02(10)
C(14)–P(1)–C(1) 104.93(10)
C(11)–P(1)–S(1) 113.86(8)
C(14)–P(1)–S(1) 119.30(8)
C(1)–P(1)–S(1) 118.09(8)
P(1)–C(11)–C(12)–P(2) = 94.9◦
C(21)–P(2)–C(24) 92.64(11)
C(21)–P(2)–C(2) 103.44(10)
C(24)–P(2)–C(2) 105.78(11)
C(21)–P(2)–S(2) 114.95(9)
C(24)–P(2)–S(2) 118.42(9)
C(2)–P(2)–S(2) 117.91(8)
Table 2 Palladium-catalyzed asymmetric allylic alkylation with chiral
diphosphine sulfides V a
Chiral sulfur-containing ligands have also been explored such as
N,S-, O,S-, P,S- and S,S-17 Among the latter, only two classes have
been reported, dithioethers18 and thioether–phosphine sulfides,3b,19
but no attention has been paid to diphosphine sulfides to the best
of our knowledge.
To evaluate the activity and selectivity of the chiral ligands
V, we have investigated the Pd-catalyzed allylic substitution of
1,3-diphenylprop-2-enyle acetate by the dimethylmalonate anion
(Scheme 2).
Run Ligand
Conversion (%)b ee (%)c (configuration) d
1
2
3
4
5
6
7
8
9
S[Rp,Rp,Rc,Rc]-V·1a 65
63(S)
S[Rp,Sp,Rc,Rc]-V·1b
R[Sp,Sp,Rc,Rc]-V·1c
68
95
66(R)
73(R)
33(S)
28(S)
30(R)
Nd
S[Rp,Rp,Rc,Rc]-V·2a 90
V·2b
74
43
17
96
21
100
97
R[Sp,Sp,Rc,Rc]-V·4a
R[Sp,Sp,Sc,Sc]-V·5a
R[Sp,Rp,Sc,Sc]-V·5b
S[Rp,Rp,Sc,Sc]-V·5c
V·6a
25(R)
44(S)
43 (S)
52(R)
10
11
S[Rp,Rp,Rc]-V·6b
a Reactions conditions: 1 mmol of 1,3-diphenylprop-2-enylacetate, 3 mmol
of dimethylmalonate with 1% palladium as [PdCl(allyl]2, BSA–AcOK,
CH2Cl2 at 40 ◦C, 24 hours. b Determined by 1H NMR. c Determined by 1H
NMR using the chiral shift reagent Eu(hfc)3. d Determined on the basis of
the sign of the specific rotation of the product.
Scheme 2 Allylic substitution reaction.
The reaction was carried out in dichloromethane at 40 ◦C
in the presence of a catalyst generated in situ from 1 mol%
of the corresponding ligand V, 0.5 mol% of p-allylpalladium
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Table 3 Palladium-catalyzed asymmetric allylic alkylation with diphos-
phines IV a
73% (S) and 52% (R), respectively, and yields of 95 and 97%. These
catalytic results are comparable with those obtained with axially
chiral thioether–phosphine sulfide ligands with a binaphthalene
framework3b in the same reaction, but remain lower than those
reported with ferrocenyl thioether–phosphine sulfides with planar
chirality19 which are the best S,S ligands in term of activity and
enantioselectivity.
An inspection of the above results shows that the sense of enan-
tioselectivity is predominantly controlled by the configuration of
the phosphorus stereocenters. The (S) enantiomer is obtained with
the (Rp,Rp) configuration of the ligand (entries 1, 4 and 9) whereas
the (R) enantiomer is obtained with the (Sp,Sp) (entries 3 and 6)
or (Rp,Sp) (Sp,Rp) (entries 2 and 8) configuration of the ligand.
Surprisingly, we can note that the enantiomeric excesses are in-
dependent of the absolute configurations of the ligand. Indeed, the
same level of enantioselectivity was obtained using ligands V·1a,
V·1b, V·1c. which have different axial and central configurations.
The reaction occurred with 63% ee for V·1a, 60% for V·1b and 73%
for V·1c (comparison entries 1, 2 and 3). In addition, all of these
three ligands give active palladium catalyst since the conversion of
the substrate in 24 h was 65% for V·1a, 68% for V·1b and 95% for
V·1c.
Reaction
time/h
Conversion
(%)b
ee
Run
Ligand
(%)c(configuration)d
11
12
13
14
15
16
IV·1
IV·2
IV·3
IV·4
IV·5
IV·6
7
5
1.5
4
2.5
5
40
54
100
100
100
100
8 (R)
16 (S)
10 (R)
66 (R)
33 (S)
14 (S)
a Reactions conditions: 1 mmol of 1,3-diphenylprop-2-enylacetate, 3 mmol
of dimethylmalonate with 1% palladium as [PdCl(allyl]2, BSA–AcOK,
CH2Cl2 at RT. b Determined by 1H NMR. c Determined by 1H NMR
using the chiral shift reagent Eu(hfc)3. d Determined on the basis of the
sign of the specific rotation of the product.
diphosphines IV (Table 3). Using diphosphines IV, the palladium
catalytic systems are more active for this allylic substitution
than disulfides V since complete conversion of the substrate was
achieved at room temperature after reaction time varying from
1.5 to 5 h. However, the enantioselectivities are significantly lower
with all of the diphosphines IV (compare runs 1, 2 and 3 to run
11; runs 4, 5 to run 12, runs 7, 8 to run 15 and runs 10, 11 to run
16) except with ligand IV·3 (compare run 6 to run 14).
From such results, the question arises on the nature of the
catalytic species. Generally, the catalysts used in palladium-
mediated allylic reaction consist of a complex containing a chiral
chelate ligand. On careful examination of the structure of the
three diastereoisomers of the ligand V·1 (Fig. 2), only the ligand
S[Rp,Sp,Rc,Rc]-V·1b can behave like a chelate ligand. For the
ligands S[Rp,Rp,Rc,Rc]-V·1a and R[Sp,Sp,Rc,Rc]-V·1c, as no
rotation around the C–C bond linking the two phosphorus atoms
occurred even at 100 ◦C in toluene according to NMR studies,
these ligands behave either like monodentate ligands leading
to mononuclear complexes or like bidentate ligands leading to
polynuclear complexes. Coordination chemistry of these S,S-
ligands towards palladium are still to be understood and further
investigations ought to be conducted.
In summary, we have demonstrated that chiral diphosphine
sulfides derived from 2,2ꢀ-biphosphole can act as a chiral ligand for
Pd and provide enantioselectivity up to 73% in asymmetric allylic
alkylation. Use of these new S,S-ligands in other asymmetric
catalytic reactions is currently in progress.
Experimental
General methods
All reactions were carried out under dry argon by using Schlenk
glassware and vacuum line techniques. Solvents were freshly dis-
tilled from standard drying agents. 1D and 2D NMR experiments
Finally, it appeared interesting to us to compare the catalytic
performance of palladium catalytic systems containing diphos-
phine sulfides V with those obtained with the corresponding
1
were carried out using the Bruker AV 500 instrument. H-2D-
31
31
COSY45{ P} and 1H–13C{ P} (HMQC, HMBC) methods using
Fig. 2 Molecular view of S[Rp,Rp,Rc,Rc]-V·1a, S[Rp,Sp,Rc,Rc]-V·1b and R[Sp,Sp,Rc,Rc]-V·1c 5
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standard pulse sequences have been employed to establish atom
connectivity and spatial relationships. Mass spectra were obtained
on a TSQ 7000 Thermoquest instrument (DCI). Optical rotations
were measured with a Perkin Elmer 241 polarimeter.
1-Phenyl-3,4-dimethylphosphole 1,8 tetraphosphole 2,9 enan-
tiomerically pure diol dimesylates (S)-4,20 (S,S)-5,21 (S,S)-6 22
and diphosphine disulfides V·1, V·2 and V·3 5 were prepared as
described in the literature.
C–CPh), 22.85 (d, JC,P = 10.0 Hz, CH2), 24.31 (s, CH3), 27.86 (s,
CH2), 29.73 (s, CH3), 31.32 (s, CH(CH3)2), 48.87 (d, JC,P = 37.5 Hz,
CH), 127.55 (s, Ph) 128.17 (s, Ph) 129;31 (s, Ph), 134.96 (d, JC,P
=
45.0 Hz, C–P), 135.48 (d, JC,P = 12.5 Hz, Ph–C–P), 149.16 (m,
1
CH3–C–C), 149.96 (m, CH3–C–C–Ph). 31P{ H} NMR (202 MHz,
CDCl3): d 66.51 (s). MS (DCI, NH3): m/z (%) = 577 (100%)
[M + H]+.
R[Sp,Sp,Rc,Rc]-(+)-P,P-Disulfur-1,1ꢀ-(1,3-diphenylpropane-1,3-
diyl)-3,3ꢀ,4,4ꢀ-tetramethyl-5,5ꢀ-diphenyl-2,2ꢀ-biphosphole; V·4
General procedure for compounds V·2, V·4 and V·6
In a Schlenk tube, naphthalene (0.02 g, 1.88 mmol) was stirred with
an excess of sodium (∼0.5 g) in dry THF (6 ml) until the solution
became green. Solid tetramer 1 (400 mg, 0.54 mmol) was then
added slowly in portions. The reaction mixture turned red and was
stirred until it became green again (∼2 h). This solution of dianion
2 and a THF solution (6 ml) of dimesylate (1.08 mmol) were
transferred dropwise by cannula at the same time into an other
Schlenk containing 200 ml of dry THF and the reaction mixture
was stirred for 16 h at room temperature. After evaporation to
dryness, the resulting residue was extracted with small portions
of pentane. The combined pentane extracts were filtered through
celite and the solvents were evaporated to give crude diphosphine
IV. Sulfur (2 equivalents) was added to a solution of compound IV
in dichloromethane (30 ml) and the reaction mixture was stirred
overnight at room temperature. After evaporation to dryness, the
mixture was chromatographed on silica gel.
Eluent: pentane–dichloromethane: 60 : 40. Yellow solid. Yield:
35% (0.237 mg, 0.376 mmol). [a]D = + 130.6 (c 0.6, CH2Cl2). 1H
NMR (500 MHz, CDCl3): d 2.01 (d, JH,P = 5.0 Hz, 6H, CH3–C–C),
2.14 (s, 6H, CH3–C–CPh), 2.69 (m, 2H, CH2), 4.65 (m, 2H, CH–
1
P), 6.84 (m, 6H, Ph), 7.02 (m, 10H, Ph) 7.22 (m, 4H, Ph). 13C{ H}
NMR (125 MHz, CDCl3): d 15.09 (d, JC,P = 1.3 Hz, CH3–C–CPh),
15.69 (d, JC,P = 1.3 Hz, CH3–C–C), 41.47 (s, CH2), 44.32 (d, JC,P
=
50.0 Hz, CH), 126.83 (s, C–P), 127.48 (s, Cpara), 128.09 (s, C meta),
128.89 (s, Cortho), 133.58 (dd, JC,P = 75.0 Hz, JC,P = 12.4 Hz, Ph–
C–P), 133.46 (d, JC,P = 10.0 Hz, Cipso), 137.49 (d, JC,P = 75.0 Hz,
1
CH3–C–C), 148.21 (m, CH3–C–C–Ph). 31P{ H} NMR (202 MHz,
CDCl3): d 53,12 (s). MS (DCI, NH3): m/z (%) = 631 (100%) [M
+ H]+. Crystals suitable for X-ray analysis were obtained by slow
evaporation of a dichloromethane solution.
(−)-P,P-Disulfur-1,1ꢀ-(butane-1,3-diyl)-3,3ꢀ,4,4ꢀ-tetramethyl-5,5ꢀ-
diphenyl-2,2ꢀ-biphosphole; V·6a
S[Rp,Rp,Rc,Rc]-(−)-P,P-disulfur-1,1ꢀ-(2,7-dimethyloctane-3,6-
diyl)-3,3ꢀ,4,4ꢀ-tetramethyl-5,5ꢀ-diphenyl-2,2ꢀ-biphosphole; V·2a
Eluent: pentane–dichloromethane: 66 : 34. Yellow solid. Yield:
42% (0.222 mg, 0.451 mmol). [a]D = −8.3 (c 1.1, CH2Cl2). mp =
◦
1
Eluent: pentane–dichloromethane: 60 : 40. Yellow solid. Yield:
245–250 C. H NMR (500 MHz, CDCl3): d 0.80 (dd, JH,P2
=
1
28% (0.173 mg, 0.300 mmol). [a]D = −290.1 (c 1.0, CH2Cl2). H
15.0 Hz, JH,H = 5.0 Hz, 3H, CH3–CH), 1.28 (m, 2H, CH2–CH),
2.10 (m, 12H, CH3–C), 2.80 (m, 1H, CH2–P1), 3.17 (m, 1H, CH–
P2), 3.67 (m, 1H, CH2–P1), 7.39 (m, 6H, Ph), 7.53 (m, 2H, Ph),
NMR (500 MHz, CDCl3): d 0.79 (dd, JH,H = 20.0 Hz, JH,H
=
5.0 Hz, 12H, (CH3)2–CH), 1.96 (m, 4H, CH2), 2.08 (s, 6H, CH3–
C–C), 2.16 (d, JH,P = 3.2 Hz, 6H, CH3–C–CPh), 2.25 (m, 2H,
CH–(CH3)2), 2.52 (m, 2H, CH–P), 7.36 (m, 2H, Ph), 7.43 (m, 4H,
7.71 (m, 2H, Ph). 13C{ H} NMR (125 MHz, CDCl3): d 15.24 (d,
1
JC,P1 = 13.6 Hz, CH3–C–CPh), 15.33 (d, JC,P2 = 11.3 Hz, CH3–C–
CPh), 15.58 (dd, JC,P1 = 12.5 Hz, JC,P = 2.2 Hz, CH3–C–C), 15.78
1
Ph) 7.87 (m, 4H, Ph). 13C{ H} NMR (125 MHz, CDCl3): d 15.36
(dd, JC,P = 10.0 Hz, JC,C = 150.9 Hz, CH3–C–C), 16.98 (s, CH3–
C–CPh), 22.83 (d, JC,P = 15.0 Hz, CH2), 25.48 (s, CH3), 27.24
(dd, JC,P2 = 12.5 Hz, JC,P1 = 2.2 Hz, CH3–C–C), 17.13 (d, JC,P =
0.5 Hz, CH3–CH), 25.90 (dd, JC,P2 = 45.6 Hz, JC,P1 = 3.8 Hz, CH),
27.30 (t, JC,P = 2.94 Hz, CH2–CH), 32.98 (dd, JC,P1 = 2.94 Hz,
JC,P2 = 40.8 Hz, CH2–P2), 128.48 (s, Ph) 128.65 (s, Ph), 129.02
(s, CH2), 29.72 (s, CH3), 32.73 (s, CH(CH3)2), 58.35 (d, JC,P
=
41.2 Hz, CH), 128.05(s, Ph) 128.45 (s, Ph) 129.06 (s, Ph), 134.54
(d, JC,P = 70.0 Hz, C–P), 135.11 (d, JC,P = 12.5 Hz, Ph–C–P),
147.31 (d, JC,P = 18.8 Hz, CH3–C–C), 154.19 (d, JC,P = 30.0 Hz,
(s, Cortho), 130.66 (d, Ph–C–P), 130.90 (d, C–Ph), 132.77 (d, JC,P
=
6.3 Hz, Cipso), 147.58 (d, JC,P = 23.9 Hz, CH3–C–C), 148.53 (dd,
1
1
CH3–C–C–Ph). 31P{ H} NMR (202 MHz, CDCl3): d 68.95 (s).
JC,P = 28.6 Hz, JC,P = 3.4 Hz, CH3–C–C–Ph). 31P{ H} NMR
MS (DCI, NH3): m/z (%) = 577 (100%) [M + H]+.
(202 MHz, CDCl3): d 51.53 (d, P1, JP1,P2 = 2.0 Hz)), 59.64 (d, P2,
JP1,P2 = 2.0 Hz). MS (DCI, NH3): m/z (%) = 493 (100%) [M +
H]+.
(−)-P,P-Disulfur-1,1ꢀ-(2,7-dimethyloctane-3,6-diyl)-3,3ꢀ,4,4ꢀ-
tetramethyl-5,5ꢀ-diphenyl-2,2ꢀ-biphosphole; VI·2b
S[Rp,Rp,Rc]-(−)-P,P-Disulfur-1,1ꢀ-(butane-1,3-diyl)-3,3ꢀ,4,4ꢀ-
tetramethyl-5,5ꢀ-diphenyl-2,2ꢀ-biphosphole; IV·6b
Eluent: pentane–dichloromethane: 40 : 60. Yellow solid. Yield:
1
27% (0.167 mg, 0.299 mmol). [a]D = −115.1 (c 1.4, CH2Cl2). H
NMR (500 MHz, CDCl3): d 0.29 (d, JH,P = 5.0 Hz, 3H, (CH3)2–
Eluent: pentane–dichloromethane: 34 : 66. Yellow solid. Yield:
CH), 0.43 (d, JH,H = 5.0 Hz, 3H, (CH3)2–CH), 0.81 (d, JH,P
=
28% (0.148 mg, 0.301 mmol). [a]D = −173.6 (c 1.0, CH2Cl2).
10.0 Hz, 3H, (CH3)2–CH), 1.03 (d, JH,H = 10.0 Hz, 3H, (CH3)2–
CH), 1.81 (m, 4H, CH2), 1.99 (m, 6H, CH3–C–C), 2.05 (s, 3H,
CH3–C–CPh), 2.09 (d, JH,P = 3.2 Hz, 3H, CH3–C–CPh), 2.38 (m,
mp = 230–235◦C. 1H NMR (500 MHz, CDCl3): d 1.23 (dd, JH,P
=
15.0 Hz, JH,H = 5.0 Hz, 3H, CH3–CH), 1.27 (m, 2H, CH2–CH),
2.11 (d, JH,P1 = 2.5 Hz, 3H, CH3–C–C), 2.17 (d, JH,P = 2.5 Hz, 3H,
CH3–C–C), 2.19 (dd, JH,P1 = 5.0 Hz, JH,H = 2.5 Hz, 3H, CH3–C–
CPh), 2.24 (dd, JH,H = 2.6 Hz, JH,P2 = 5.0 Hz, 6H, CH3–C–CPh),
2.30 (m, 1H, CH–P2), 2.44 (m, 1H, CH2–P1), 2.64 (m, 1H, CH2–
2H, CH–(CH3)2), 4.76 (m, 2H, CH–P), 7.36 (m, 6H, Ph), 7.71 (m,
1
4H, Ph). 13C{ H} NMR (125 MHz, CDCl3): d 15.25 (dd, JC,P
=
12.5 Hz, JC,C = 25.0 Hz, CH3–C–C), 16.31 (d, JC,P = 10.0 Hz, CH3–
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P1), 7.36 (m, 2H, Ph), 7.43 (m, 4H, Ph), 7.57 (m, 2H, Ph), 7.68 (m,
References
1
2H, Ph). 13C{ H} NMR (125 MHz, CDCl3): d 15.22 (d, JC,P1
=
1 (a) I. Ojima, Catalytic Asymmetric Synthesis, 2nd edn, Wiley-VCH,
New York, 2000; (b) E. N. Jacobsen, A. Pfaltz, H. Yamamoto,
Comprehensive Asymmetric Catalysis, Springer-Verlag, Berlin, 1999;
(c) R. Noyori, Asymmetic Catalysis in Organic Synthesis, Wiley, New
York, 1994.
2 (a) For recent reviews: M. Mc Carthy and P. J. Guiry, Tetrahedron,
2001, 57, 3809; (b) H. Shimizu, I. Nagasaki and T. Saito, Tetrahedron,
2005, 61, 5405.
3 (a) S. Gladiali, S. Medici, G. Pirri, S. Pulacchini and D. Fabbri,
Can. J. Chem., 2001, 79, 670; (b) W. Zhang, Q. Xu and M. Shi,
Tetrahedron: Asymmetry, 2004, 15, 3161; (c) J. W. Faller, J. C. Wilt
and J. Parr, Org. Lett., 2004, 15, 3467.
13.6 Hz, CH3–C–CPh), 15.30 (d, JC,P2 = 11.3 Hz, CH3–C–CPh),
16.07 (d, JC,P1 = 12.5 Hz, CH3–C–C), 16.29 (d, JC,P2 = 12.5 Hz,
CH3–C–C), 23.32 (d, JC,P = 0.5 Hz, CH3–CH), 28.96 (d, JC,P2
45.6 Hz, CH), 29.30 (d, JC,P = 2.94 Hz, CH2–CH), 37.52 (d, JC,P2
=
=
40.8 Hz, CH2–P2), 128.14 (s, Ph) 128.19 (s, Ph), 128.66 (s, Cortho),
128.89 (s, Ph–C–P), 128.92 (s, C–Ph), 148.72 (d, JC,P = 6.3 Hz,
Cipso), 151.44 (d, JC,P = 23.9 Hz, CH3–C–C), 151.77 (dd, JC,P
=
1
28.6 Hz, JC,P = 3.4 Hz, CH3–C–C–Ph). 31P{ H} NMR (202 MHz,
CDCl3): d 54.82 (d, P1), 64.47 (d, P2, JP1,P2 = 2.0 Hz). MS (DCI,
NH3): m/z (%) = 493 (100%) [M + H]+.
4 The word atropos consists of “a” meaning “not” and “tropos” meaning
“turn” in Greek.
5 E. Robe´, C. Orte´ga, M. Mikina, M. Mikolajczyk, J-C. Daran and M.
Gouygou, Organometallics, 2005, 24, 5549.
General procedure for the allylic substitution reaction
6 (a) O. Tissot, M. Gouygou, F. Dallemer, J-C. Daran and G. G. A.
Balavoine, Angew. Chem., Int. Ed., 2001, 40, 1076; (b) C. Orte´ga, M.
Gouygou and J-C. Daran, Chem. Commun., 2003, 1154.
7 A. Breque, F. Mathey and P. Savignac, Synthesis, 1981, 983.
8 F. Mathey, F. Mercier, F. Nief, J. Fischer and A. Mitschler, J. Am.
Chem. Soc., 1982, 104, 2077.
A mixture of ligand V, 1,3-diphenylprop-2-enylacetate (0.413 g,
1.63 mmol) and [(Pd(C3H5)Cl)]2 (3 mg, 0.03 mmol) in dry
dichloromethane (20 mL) was stirred at room temperature for
2 h. To the resulting solution were added dimethyl malonate
(0.374 mL, 3.25 mmol), small amount of potassium acetate and
BSA (0.300 mL, 3.25 mmol). The reaction was carried out at 40 ◦C
during 24 hours. The resulting mixture was diluted with diethyl
ether (5 ml) and quenched with a saturated aqueous solution of
ammonium chloride (5 ml). The aqueous phase was extracted
with Et2O, the combined organic layers were dried over sodium
sulfate, filtered and evaporated. The conversion was calculated
from the crude reaction mixture by 1H NMR spectroscopy.
Subsequent purification by chromatography on silica eluting with
ethyl acetate–pentane (15 : 85) afforded the product as a white
solid. The enantiomeric excess was determined by 1H NMR using
the chiral shift reagent Eu(hfc)3.
9 Nucleophilic substitution on carbon resulted in inversion of configura-
tion in the case of compounds 2–6.
10 E. Robe´, PhD thesis, Universite´ Paul Sabatier, Toulouse, France.
11 Crystal data.† R[Rp,Sp,Sc,Sc]-V·4: C40H36Cl2P2S2, M = 713.65, mono-
◦
˚
clinic, a = 30.136(2), b = 6.5916(4), c = 22.9460(13) A, b = 127.764(8) ,
3
˚
U = 3603.4(4) A , T = 180 K, space group C2, Z = 4, Dx = 1.315, l(Mo
Ka) = 0.413 mm−1, 16 290 reflections measured, 6325 unique (Rint
=
0.022) which were used in all calculations. The final R and wR(F2)
were 0.0365 and 0.0962, respectively, (I>2r(I) (Flack’s parameter) =
0.00(6). CCDC reference number 669755.
12 H. D. Flack, Acta Crystallogr., Sect. A: Found. Crystallogr., 1983, 39,
876.
13 B. M. Trost and D. L. van Vranken, Chem. Rev., 1996, 96, 395.
14 A. Pfaltz, Acc. Chem. Res., 1993, 26, 339.
15 (a) B. Trost, Acc. Chem. Res., 1996, 29, 355; (b) R. Pre´voˆt and A. Pfaltz,
Angew. Chem., Int. Ed., 1998, 37, 323.
16 D. A. Evans and T. A. Brandt, Org. Lett., 1999, 1, 1563.
17 For a recent review on chiral sulfur-containing ligands for asymmetric
allylic substitution: H. Pelissier, Tetrahedron, 2007, 63, 1297 and
references therein.
X-Ray crystallographic study†
R[Sp,Sp,Rc,Rc]-(+)-P,P-Disulfur-1,1ꢀ-(1,3-diphenylpropane-1,3-
diyl)-3,3ꢀ,4,4ꢀ-tetramethyl-5,5ꢀ-diphenyl-2,2ꢀ-biphosphole, V·4.
A single crystal was mounted under inert perfluoropolyether at
the tip of a glass fiber and cooled in the cryostream of an Oxford-
Diffraction XCALIBUR CCD diffractometer for. Data were
collected using monochromatic Mo Ka radiation (k = 0.71073).
The structures was solved by direct methods (SIR9723) and refined
by least-squares procedures on F2 using SHELXL-97.24 All H
atoms were introduced in calculation in idealized positions and
treated as riding on their parent C atoms. The drawing of the
molecule was realized with the help of ORTEP-3.25
18 (a) S. Jansat, M. Go´mez, G. Muller, M. Die´guez, A. Aghmiz, C. Claver,
A. M. Masdeu-Bulto´, L. Flores-Santos, E. Martin, M. A. Maestro and
J. Mah´ıa, Tetrahedron: Asymmetry, 2001, 12, 1469; (b) N. Khian, C. S.
Arau´jo, E. Alvarez and I. Ferna´ndez, Tetrahedron Lett., 2003, 44, 3401;
(c) Y. Okuyama, H. Nakano, K. Takahashi, H. Hongo and C. Kabuto,
Chem. Commun., 2003, 524; (d) F. Ferna´ndez, M. Go´mez, S. Jansat,
G. Muller, E. Martin, L. Flores-Santos, P. X. Garc´ıa, A. Acosta, A.
Aghmiz, M. Gime´nez-Pedro´s, A. M. Masdeu-Bulto´, M. Die´guez, C.
Claver and M. A. Maestro, Organometallics, 2005, 24, 3946.
19 L. Routaboul, D. Vincendeau, J-C. Daran and E. Manoury, Tetrahe-
dron: Asymmetry, 2005, 16, 2685.
20 P. A. MacNeil, N. K. Roberts and B. Bosnich, J. Am. Chem. Soc., 1981,
103, 2273.
21 G. H. Roos and A. R. Donovan, Tetrahedron: Asymmetry, 1999, 10,
991.
22 Y. Y. Yan and T. V. RajanBabu, Org. Lett., 2000, 2, 4137.
23 A. Altomare, M. C. Burla, M. Camalli, G. L. Cascarano, C. Giacov-
azzo, A. Guagliardi, A. G. G. Moliterni, G. Polidori and R. Spagna,
J. Appl. Crystallogr., 1999, 32, 115.
24 G. M. Sheldrick, SHELXL-97, Program for refinement of crystal
structures, University of Go¨ttingen, Germany, 1997.
25 (a) M. N. Burnett and C. K. Johnson, ORTEP-III: Oak Ridge Thermal
Ellipsoid Plot Program for Crystal Structure Illustrations, Report
ORNL-6895, Oak Ridge National Laboratory, Oak Ridge, TN, USA,
1996; (b) L. J. Farrugia, J. Appl. Crystallogr., 1997, 30, 565.
Acknowledgements
Research supported by the Centre National de la Recherche Sci-
entifique, the Ministe`re de l’Education Nationale de la Recherche
et de la Technologie (E. R. grant), the Universite´ Paul Sabatier de
Toulouse (E. R.), the Ministry of Sciences and Higher Education
in Poland (Grant No 20/MOM/2006/03 to M. M.).
2898 | Dalton Trans., 2008, 2894–2898
This journal is
The Royal Society of Chemistry 2008
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