Resolution of Benzylcyclohexylphenylphosphine by Palladium(II)-Amine Metallacycles. A New Ligand for Asymmetric Hydrovinylation

Article abstract of DOI:10.1021/om990302d

The synthesis of benzylcyclohexylphenylphosphine and its resolution by means of optically active palladium metallacycles are reported. The absolute configuration of (R_C,S_P)-[PdCl(C₆H₄-CHMeNMe ₂)(PBzCy

Full text of DOI:10.1021/om990302d

Organometallics 1999, 18, 3511-3518
3511
Resolu tion of Ben zylcycloh exylp h en ylp h osp h in e by
P a lla d iu m (II)-Am in e Meta lla cycles. A New Liga n d for
Asym m etr ic Hyd r ovin yla tion
J oan Albert,† J . Magali Cadena,† J aume Granell,*,†,§ Guillermo Muller,*,†
J uan I. Ordinas,† David Panyella,† Carmen Puerta,‡ Carolina San˜udo,† and
Pedro Valerga‡
Departament de Quı´mica Inorga`nica, Universitat de Barcelona, Diagonal 647,
08028 Barcelona, Spain, and Departamento de Ciencia de los Materiales,
Ingenierı´a Metalu´rgica y Quı´mica Inorga´nica, Facultad de Ciencias, Universidad de Ca´diz,
Apdo. 40, 11510 Puerto Real, Ca´diz, Spain
Received April 26, 1999
The synthesis of benzylcyclohexylphenylphosphine and its resolution by means of optically
active palladium metallacycles are reported. The absolute configuration of (RC,SP)-[PdCl(C6H4-
CHMeNMe2)(PBzCyPh)] has been determined by single-crystal X-ray analyses. The allyl
complex [Pd(η3-2-MeC3H4)(PBzCyPh)S]BF4, prepared in situ from [Pd(η3-2-MeC3H4)Cl-
(PBzCyPh)] and AgBF4 in CH2Cl2 solution, was used as a precatalyst for asymmetric
hydrovinylation of styrene and 2-vinylnaphthalene. This system permits the synthesis of
3-phenyl-1-butene and 3-(2-naphthyl)-1-butene with good ee values working in very mild
conditions of temperature (15 °C).
In tr od u ction
[MCl(allyl)L] compounds (M ) Ni, Pd; L ) monodentate
phosphine) are precursors of active species in the
catalytic hydrovinylation of olefins, and the activity of
the catalyst increases with increasing bulk of the
modifying ligand, up to a certain point, beyond which a
sharp decline is observed.3a These facts prompted us to
prepare the benzylcyclohexylphenylphosphine, which
due to its steric bulk and electronic features, seems to
be a promising precursor of active species in the
asymmetric hydrovinylation of olefins.
We report the synthesis of this monodentate phos-
phine, its resolution by palladium metallacycles, the
synthesis of the optically active allyl compound [Pd(η3-
2-MeC3H4)Cl(PBzCyPh)], and studies of the asymmetric
hydrovinylation of styrene and 2-vinylnaphthalene,
using this allyl complex as a precursor of catalytic
species.
Spectacular progress has been made in the field of
asymmetric catalysis by using homogeneous catalysts
based on transition metal complexes modified by chiral
ligands. In this way chiral phosphines have become very
important in asymmetric catalysis.1 Among the pleni-
tude of chiral phosphines developed for application in
asymmetric catalysis, examples of monodentate ligands
possessing a stereogenic phosphorus atom are rare, even
though metal complexes featuring marked asymmetry
near the catalytic center are considered to be excellent
optical inducers.2 In some catalytic processes such as
the hydrovinylation reaction the catalyst becomes inac-
tive in the presence of bidentate phosphines and par-
ticular attention has thus been given to systems con-
taining Horner phosphines. Unfortunately optically
pure Horner phosphines are not easy to prepare, and a
series of phosphines having optically active substituents
such as menthyl or myrtanyl have been synthesized and
used in asymmetric hydrovinylation as an alternative.1e,3
Asymmetric hydrovinylation of vinyl aromatic deriva-
tives can afford 3-phenyl-1-butene and related deriva-
tives, which are starting materials for the synthesis of
2-arylpropionic acids, which are widely used as antiin-
flammatory drugs, such as ibuprofen and naproxen.4
Discu ssion a n d Resu lts
The chiral phosphine was synthesized by reaction
between dibenzylphenylphosphine and lithium metal in
THF under a dry nitrogen atmosphere. After 20 h of
stirring at room temperature complete cleavage of one
of the CH2-P bonds of the dibenzylphenylphosphine
was accomplished, with the formation of the phenyl-
benzylphosphide anion. 31P NMR spectra, under nitro-
gen, clearly illustrated the formation of this anion (δ )
-37.1 ppm) and were used to monitor the progress of
the reaction. Subsequent addition of cyclohexyl bromide
afforded the racemic (()-benzylcyclohexylphenylphos-
† Universitat de Barcelona.
‡ Universidad de Ca´diz.
§ Fax: 34-934907725. E-mail: jgranell@kripto.qui.ub.es.
(1) (a) Noyori, R. Asymmetric Catalysis in Organic Synthesis; J ohn
Wiley and Sons: New York, 1994. (b) Hermann, W. A.; Cornils, B.
Angew. Chem., Int. Ed. Engl. 1997, 36, 1049. (c) Kagan, H. B.
Asymmetric Synthesis; Morrison, J . D., Ed.; Academic Press: Orlando,
FL, 1985; Vol. 5, Chapter 1. (d) Catalytic Asymmetric Synthesis; Ojima,
I., Ed.; VCH Publishers: Weinheim, 1993. (e) J olly, P. W.; Wilke, G.
Applied Homogeneous Catalysis with Organometallic Compounds;
Hermann, W. A., Cornils, B., Eds.; VCH: Weinheim, 1996; Vol. 2; p
1024.
(3) (a) Wilke, G. Angew. Chem., Int. Ed. Engl. 1988, 27, 186. (b)
Muller, G.; Ordinas, J . I. J . Mol. Catal. A 1997, 125, 97.
(4) (a) Rieu, J . P.; Boucherle, A.; Cousse, H.; Mouzin, G. Tetrahedron
1986, 42, 4095. (b) Sonawane, H. R.; Bellur, N. S.; Ahuja, J . R.;
Kulkarni, D. G. Tetrahedron: Asymmetry 1992, 3, 163
(2) (a) Pietrusiewicz, K. M.; Zablocka, M. Chem. Rev. 1994, 94, 1375.
10.1021/om990302d CCC: $18.00 © 1999 American Chemical Society
Publication on Web 07/30/1999

3512 Organometallics, Vol. 18, No. 17, 1999
Albert et al.
Sch em e 1a
a
(i) Li, THF, room temperature, 20 h; (ii) C6H11Br, THF, room temperature, 10 min; (iii), NiCl2, THF/EtOH, room temperature,
15 min.
Sch em e 2a
a
(i) [NiCl2(PBzCyPh)2], THF, room temperature, 45 min; (ii) dppe, [Pd(µ-Cl)(η3-2-MeC3H4)]2, ether, room temperature, 45 min.
phine 1, in THF solution. A saturated solution of NiCl2
the mononuclear complexes [PdCl(C-N)(PBzCyPh)], as
a 1:1 mixture of diastereoisomers (RC,RP)-4 and (RC,-
SP)-4 (see Scheme 2). All the new organometallic
compounds obtained were characterized by elemental
in absolute ethanol was added to the organic layer, and
then the resulting solution was stirred for 15 min and
concentrated in vacuo to afford dark red crystals of the
complex dichlorobis[(()-benzylcyclohexylphenylphos-
phine]nickel(II) (2) (see Scheme 1).
Benzylcyclohexylphenylphosphine is readily oxidable
and should be stored under nitrogen, but when coordi-
nated to nickel, this ligand becomes very stable and can
be stored for several months in air. Besides, this nickel
coordination compound permits the synthesis of met-
allacycles 4, by ligand transfer reactions (see Scheme
2).
1
analysis, IR spectra, and H and 31P NMR spectra. In
some cases, 2D-NMR experiments and positive FAB-
mass spectra were carried out to complete the charac-
terization. The high-field shift of the aromatic protons
of the palladated ring in 4, due to the aromatic rings of
the phosphine, indicates the cis disposition of the
phosphorus relative to the metalated carbon atom, and
the chemical shift of the phosphorus in 4 confirms this
arrangement.7
The versatility of ortho-palladated derivatives of
optically active N-donor ligands as resolving agents for
Lewis bases has been convincingly demonstrated. These
complexes have been widely used for the resolution of
bidentate and monodentate ligands.5 The optically pure
cyclopalladated dinuclear compounds 3 were obtained
from the optically active amines as reported.6 Reaction
of dimers 3 with the coordination compound dichlorobis-
[(()-benzylcyclohexylphenylphosphine]nickel(II) afforded
Resolu tion of th e P h osp h in e. Attempts to separate
the diastereoisomers (RC,RP)-4a and (RC,SP)-4a by re-
crystallization were unsuccessful, but the elution of the
mixture of (RC,RP)-4a and (RC,SP)-4a through a SiO2
column, using chloroform-acetone (100:2) as eluent,
allowed the separation of the diastereoisomer (RC,RP)-
4a in 84% yield (42% with respect to the total Pd), with
a 90% de (see below for the assignment of absolute
configuration). Nevertheless, better results were ob-
tained with 4b and 4c. The recrystallization of a
saturated solution of a mixture of (RC,RP)-4b and
(RC,SP)-4b in ether afforded the diastereoisomer (RC,SP)-
(5) Wild, S. B. Coord. Chem. Rev. 1997, 166, 291. (b) Robin, F.;
Mercier, F.; Ricard, L.; Mathey, F.; Spagnol, M. Chem. Eur. J . 1997,
8, 1365. (c) Dunina, V. V.; Golovan, F. B. Tetrahedron: Asymmetry
1995, 6, 2747. (d) Leung, P.; Quek, G. H.; Lang, H.; Liu, A. M.; Mok,
K. F.; White, A. J .; Williams, D. J .; Rees, N.; McFarlane, W. J . Chem.
Soc., Dalton Trans. 1998, 1639. (e) Barclay, C. E.; Deeble, G.; Doyle,
R. J .; Elix, S. A.; Salem, G.; J ones, T. L.; Wild, S. B.; Willis, A. C. J .
Chem. Soc., Dalton Trans. 1995, 57. (f) Pabel, M.; Willis, A. C.; Wild,
S. B. Inorg. Chem. 1996, 35, 1244. (g) Berens, U.; Brown, J . M.; Long,
J .; Selke, R. Tetrahedron: Asymmetry 1996, 7, 285. (h) Chelucci, G.;
Cabras, M. A.; Saba, A.; Sechi, A. Tetrahedron: Asymmetry 1996, 7,
1027. (i) Gladiali, S.; Dore, A.; Fabbri, D.; De Lucci, O.; Manassero,
M. Tetrahedron: Asymmetry 1994, 5, 511. (j) Chooi, S. Y. M.; Tan, M.
K.; Leung, P.; Mok, K. F. Inorg. Chem. 1994, 33, 3096. (k) Pabel, M.;
Willis, A. C.; Wild, S. B. Tetrahedron: Asymmetry 1995, 6, 2369.
(6) (a) Otsuka, S.; Nakamura, A.; Kano, T.; Tani, K. J . Am. Chem.
Soc. 1971, 54, 4301. (b) Vicente, J .; Saura-Llamas, I.; J ones, P. G. J .
Chem. Soc., Dalton Trans. 1993, 3619. (c) Albert, J .; Cadena, J . M.;
Granell, J . Tetrahedron: Asymmetry 1997, 8, 991.
(7) (a) Allen, D. G.; McLaughlin, G. M.; Robertson, G. B.; Steffen,
W. L.; Salem, G.; Wild, S. B. Inorg. Chem. 1982, 21, 1007. (b) Albert,
J .; Go´mez, M.; Granell, J .; Sales, J .; Solans, X. Organometallics 1990,
9, 1405. (c) Albert, J .; Granell, J .; Sales, J .; Font-Bardia, M.; Solans,
X. Organometallics 1995, 14, 1393. (d) Barclay, C. E.; Deeble, G.; Doyle,
R. J .; Elix, S. A.; Salem, G.; J ones, T. L.; Wild, S. B.; Willis, A. C. J .
Chem. Soc., Dalton Trans. 1995, 57.

Resolution of Benzylcyclohexylphenylphosphine
Organometallics, Vol. 18, No. 17, 1999 3513
cyclopalladated derivative 3. The free phosphine is
readily oxidable and should be stored under nitrogen,
but no racemization was observed when the phosphine
was stored for several days in THF solution. The
addition of dppe to solutions of each one of the different
diastereoisomers of 4a or 4c and subsequent reaction
of the free phosphine formed with the cyclopalladated
compound 3b permitted the determination of the abso-
lute configuration of the phosphine on each of the
diastereoisomers by 31P NMR.
Syn th esis of [P d (η3-2-MeC3H4)Cl(P BzCyP h )], 5.
This compound, containing the racemic phosphine as
ligand, was obtained by reaction between dichlorobis-
[(()-benzylcyclohexylphenylphosphine]nickel(II) and the
dinuclear allyl complex [Pd(µ-Cl)(η3-2-MeC3H4)]2, in
toluene. This complex was characterized by elemental
1
analysis, IR spectra, FAB-mass spectra, and H and 31P
NMR spectra. NMR data show that 5 occurs in two
diastereomeric forms, I and II, because of the lack
of a symmetry plane in this complex (see Scheme 2).
Proton NMR data of the allylic group were assigned
by comparison with literature values.8 Unusually high-
field shifts of Hc and Hd were observed, showing that
these protons are in close proximity to aromatic phos-
F igu r e 1. ORTEP plot of the structure of (RC,SP)-4b.
Ta ble 1. Selected Bon d Len gh ts (Å) a n d An gles
(d eg) for (RC,SP )-4b
1
phine rings. 2D H NMR ROESY experiments, carried
Pd(1)-Cl(1)
Pd(1)-P(1)
Pd(1)-N(1)
Pd(1)-C(1)
P(1)-C(11)
P(1)-C(17)
P(1)-C(23)
N(1)-C(7)
N(1)-C(9)
N(1)-C(10)
C(1)-C(2)
C(1)-C(6)
2.418(4)
2.244(3)
2.13(1)
2.00(1)
1.86(1)
1.81(1)
1.82(1)
1.54(2)
1.46(2)
1.47(2)
1.33(1)
1.41(1)
Cl(1)-Pd(1)-P(1)
Cl(1)-Pd(1)-N(1)
P(1)-Pd(1)-C(1)
N(1)-Pd(1)-C(1)
C(11)-P(1)-C(17)
C(11)-P(1)-C(23)
C(17)-P(1)-C(23)
92.2(1)
90.9(3)
96.2(3)
out in CDCl3 solutions, permitted the unambiguous
assignment of the NMR spectrum. In addition to the
negative NOE cross-peaks which arise from cross-
relaxation, the phase-sensitive 2D ROESY experiment
also shows a series of positive cross-peaks connecting
the diastereoisomers I and II of compound 5, thereby
indicating that these isomers are in equilibrium in
solution; see Table 2. These data also show that the
interconversion between both diastereoisomers mainly
occurs via the π-σ-π process, by opening the Pd-C
bond trans to the phosphorus atom. The syn-syn, anti-
anti exchange (apparent allyl rotation) is also ob-
served.8,9
The X-ray structure of 5, containing racemic phos-
phine as ligand, has been determined (Figure 2).
Compound 5 crystallizes in the P21/n group. The crystal
structure consists of discrete molecules separated by van
der Waals distances. The unit cell contains only the
stereoisomers SP-I and RP-II, these molecules being one
of the two pairs of enantiomers possible. The structure
confirms the typical geometry of an η3-allyl bound to a
transition metal, and the stereochemistry around pal-
ladium is approximately square-planar. Bond distances
and angles are similar to those reported for related allyl
compounds, and the different Pd-C lengths are in
agreement with the larger trans influence of phosphine
82.1(4)
102.8(5)
101.6(5)
108.9(6)
4b in 70% yield (35% with respect to the total Pd) with
a de higher than 95%, and the elution of the mixture of
(RC,RP)-4c and (RC,SP)-4c in a SiO2 column (30 × 400
mm, 50 g SiO2) with CHCl3-acetone (100:3) as eluent
permitted the separation of the diastereoisomers (RC,RP)-
4c and (RC,SP)-4c in 70 and 66% yield, respectively (35
and 33% with respect to the total Pd), with a de higher
than 95% in both cases.
The absolute configuration of the phosphine in (RC,SP)-
4b was determined by X-ray crystallography (Figure 1).
The crystal structure consists of discrete molecules
separated by van der Waals distances. Bond distances
and angles are similar to those reported for related
metallacycles; see Table 1.7b,c The palladium atom is in
a square-planar environment, coordinated to carbon,
chlorine, nitrogen, and phosphorus atoms. The coordi-
nation plane shows a tetrahedral distortion, the devia-
tion from the mean plane being +0.08, +0.43, -0.01,
and -0.18 Å for Cl, C1, P, and N, respectively. The
phosphorus and nitrogen atoms adopt a trans arrange-
ment, and the absolute configuration of the phosphine
ligand in this diastereoisomer is S.
(8) (a) Maitlis, P. M.; Espinet, P.; Russell, M. J . H. Comprehensive
Organometallic Chemistry; Wilkinson, G., Stone, F. G. A., Abel, E. W.,
Eds.; Pergamon: Oxford, 1982; Vol. 6, Chapter 38, p 411. (b) Elguero,
J .; Fruchier, A.; de la Hoz, A.; J alo´n, F.; Manzano, B.; Otero, A.; Go´mez
de la Torre, F. Chem. Ber. 1996, 129, 384. (c) Crociani, B.; Antonaroli,
S.; Paci, M. Organometallics 1997, 16, 384.
(9) (a) Pregosin, P. S.; Trabesinger, G. J . Chem. Soc., Dalton Trans.
1998, 727. (b) Gogoll, A.; O¨ rnebro, J .; Grennberg, H.; Ba¨ckvall, J . E.
J . Am. Chem. Soc. 1994, 116, 3631. (c) Ankersmit, H. A.; Løken, B.
H.; Kooijman, H.; Spek, A. L.; Vrieze, K.; van Koten, G. Inorg. Chim.
Acta 1996, 252, 141. (d) Albinati, A.; Kunz, R. W.; Amman, C. J .;
Pregosin, P. S. Organometallics 1991, 10, 1800. (e) Pregosin, P. S.;
Salzmann, R. Coord. Chem. Rev. 1996, 155, 35. (f) Breutel, C.; Pregosin,
P. S.; Salzmann, R.; Togni, A. J . Am. Chem. Soc. 1994, 116, 4067. (g)
Sprinz, J .; Kiefer, M.; Helmchen,. G.; Reggelin, M.; Huttner, G.; Walter,
O.; Zsolnai, L. Tetrahedron Lett. 1994, 35, 1523. (h) Vrieze, K.; Cosee,
P.; Praat, A. P.; Hilbers, C. W. J . Organomet. Chem. 1968, 11, 353.
The action of 1,2-bis(diphenylphosphino)ethane (dppe)
on the optically pure cyclopalladated derivatives 4 led
to the enantiopure free phosphine PBzCyPh (31P NMR:
δ ) -6.1). The displacement proceeds with retention of
the configuration at phosphorus, as verified by the
quantitative regeneration of the starting material 4
from the free ligand and the corresponding dinuclear

3514 Organometallics, Vol. 18, No. 17, 1999
Ta ble 2. Selected 2D 1H NMR ROESY Da ta for 5a
Albert et al.
negative NOEs
exchange cross-peaks (positive NOEs)
Ha(isomers I, II) [4.45]‚‚‚Hb(isomer II) [3.44] (s)
Ha(isomers I, II) [4.45]‚‚‚Hb(isomer I) [3.41] (s)
Hc(isomer I) [2.95]‚‚‚Hd(isomer I) [2.03] (s)
Hc(isomer II) [2.89]‚‚‚Hd(isomer II) [2.44] (s)
Ha(isomers I, II) [4.45]‚‚‚Me (isomer I) [1.86] (w)
Ha(isomers I, II) [4.45]‚‚‚Me (isomer II) [1.76] (w)
Hc(isomer I) [2.95]‚‚‚Me (isomer I) [1.86] (w)
Hc(isomer II) [2.89]‚‚‚Me (isomer II) [1.76] (w)
Ha(isomers I, II) [4.45]‚‚‚Hc(isomer I) [2.95] (m)
Ha(isomers I, II) [4.45]‚‚‚Hc(isomer II) [2.89] (m)
Hb(isomer II) [3.44]‚‚‚Hd(isomer I) [2.03] (m)
Hb(isomer I) [3.41]‚‚‚Hd(isomer II) [2.44] (m)
Hc(isomer I) [2.95]‚‚‚Hd(isomer II) [2.44] (s)
Hc(isomer II) [2.89]‚‚‚Hd(isomer I) [2.03] (s)
a
In CDCl3 at 20 °C; values in brackets are the proton chemical shifts in ppm; s ) strong, m ) medium, w ) weak.
metal-alkyl bond stabilized, in the case of vinylaro-
matic derivatives, in the form of an η3-benzylic complex.
This is the step where the asymmetric induction is
created.11 Insertion of the second olefin into the metal-
carbon bond, followed by a â-elimination reaction, gives
the organic product and regenerates the metal-hydride
catalyst.3,12,13
The main interest in hydrovinylation reaction lies in
the generation of a new asymmetric center, and con-
siderable effort has been invested in obtaining high
enantioselectivity by modifying the metal atom with
optically active ligands. Highly enantioselective hy-
drovinylation of styrene to produce 3-phenyl-1-butene
in 95% enantiomeric excess has been described using
the allyl-nickel complex [Ni(η3-C3H5)ClL*] in the pres-
ence of Et2AlCl, where L* is a dimeric aminophosphine
derived from (R)-myrtenal and (S)-1-phenylethylamine,
but reaction temperatures as low as -70 °C are
needed.1e,3a The same system has been used to obtain
(-)-(R)-3-(6-methoxy-2-naphthyl)-1-butene, a naproxen
intermediate, in 72% yield and 83.2% enantiomeric
excess.14 Recently, it has been shown that the hydrovi-
nylation of various vinylarenes proceeds with an excel-
lent chemical yield and selectivity, when a combination
of allylnickel bromide dimer, a weakly coordinating
counterion such as triflate, and a monophosphine is
employed as the precatalyst. In addition, an enantiose-
lectivity up to 80% was obtained when the reaction was
performed at -70 °C, using an optically active mono-
phosphine that carries a hemilabile group.15 Palladium
compounds [Pd(η3-C3H4R)L]X (L ) menthyldialkyl- or
alkylarylphosphinite, X ) SbF6, ClO4, BF4; CF3SO3)
catalyze the asymmetric hydrovinylation of styrene at
0 °C to give 3-phenyl-1-butene in 34% yield with 80%
enantiomeric excess.16
F igu r e 2. ORTEP plot of the structure of 5.
Ta ble 3. Selected Bon d Len gh ts (Å) a n d An gles
(d eg) for 5
Pd(1)-Cl(1)
Pd(1)-P(1)
Pd(1)-C(1)
Pd(1)-C(2)
Pd(1)-C(3)
P(1)-C(5)
P(1)-C(11)
P(1)-C(17)
C(1)-C(2)
C(2)-C(3)
C(2)-C(4)
2.356(2)
2.292(2)
2.178(9)
2.162(8)
2.104(9)
1.811(9)
1.838(9)
1.830(9)
1.38(1)
Cl(1)-Pd(1)-P(1)
Cl(1)-Pd(1)-C(1)
C(1)-C(2)-C(3)
C(1)-C(2)-C(4)
92.04(8)
98.7(3)
113.7(9)
123.3(9)
1.44(1)
1.48(1)
with respect to the chloro ligand; see Table 3.10 The
dihedral angle between the plane defined by carbon
atoms C1, C2, and C3 and that defined by the pal-
ladium, phosphorus, and chlorine atoms is 68.7°. The
methyl group is 0.2 Å out of the plane defined by C1,
C2, and C3, the other carbon atoms of the allyl ligand.
Compound 5, containing the phosphine in optically
pure form, can be obtained by the addition of dppe to a
solution of one of the optically pure diastereoisomers 4,
in a 1:1 ratio, and subsequent reaction of the free
phosphine formed with the dinuclear allyl complex [Pd-
(µ-Cl)(η3-2-MeC3H4)]2.
Ca ta lytic Hyd r ovin yla tion . Palladium and nickel
π-allyl compounds are good precursors for the catalytic
hydrovinylation of olefins. Although important details
remain unclear, it is generally accepted that the key
intermediate is a cationic M(II) hydride complex (see
Scheme 3), which reacts with the olefin to afford a
(10) (a) Mason R.; Russell, D. R. Chem. Commun. 1966, 26. (b)
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Chem. Soc. (A) 1968, 2549.
(11) Angermund, K.; Eckerle, A.; Lutz, A. Z. Naturforsch., B 1995,
50, 488.
(12) For nickel systems see: (a) Kawata, N.; Maruya, K.; Mizoroki,
T.; Okazi, A. Bull. Chem. Soc. J pn. 1971, 44, 3217. (b) Wilke, G.;
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Tatsuoka, K.; Shimizu, T. U.S. Patent, 30,803,254, 1974; Chem. Abstr.
1975, 82, 44004b. (b) Drent, E. U.S. Patent, 5,227,561, 1993; Chem.
Abstr. 1994, 120, 31520v. (c) Britovsek, G. P.; Keim, W.; Mecking, S.;
Sainz, D.; Wagner, T. J . Chem. Soc., Chem. Commun. 1993, 1632.
(14) Wilke, G.; Monkiewicz, J .; Kuhn, H. U.S. Patent, 4,912,274, Mar
27, 1990; Chem. Abstr. 1991, 114, 43172x.
(15) Nomura, N.; J in, J .; Park, H.; RajanBabu, T. V. J . Am. Chem.
Soc. 1998, 120, 459.

Resolution of Benzylcyclohexylphenylphosphine
Organometallics, Vol. 18, No. 17, 1999 3515
Sch em e 3
Ta ble 4. Hyd r ovin yla tion Rea ction of Styr en e a n d 2-Vin yln a p h th a len ea
olefin
solvent T (°C) t (min) conversion (%)c selectivity (%)d C16-fraction (%)e TOF/hf ee (%)
styrene
run catalystb
1
rac
R
rac
R
rac
R
S
rac
S
R
THF
THF
10
25
0
60
60
120
90
60
30
30
60
20
60
30
16.2
33.2
13.2
64.8
61.5
61.5
32.5
99.9
83.0
100
99
0.6
3.0
0.8
4.3
3.2
5.5
2.9
5.2
56
300
62
2
styrene
styrene
styrene
styrene
styrene
styrene
styrene
45-S
3
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
100
99
4
5
405
585
1290
590
947
250
100
400
61-S
5
10
15
15
15
15
15
15
97
6
98
60-S
59-R
7
99
8
83
9
2-vinylnaphthalene CH2Cl2
2-vinylnaphthalene CH2Cl2
98.5
84-R
85-S
10
11
100
21.3
58
100
6
styrene
CH2Cl2
1.2
a
b
Initial ethylene pressure 15 bar; ratio olefin/catalyst 1000:1 for styrene and 100:1 for 2-vinylnaphthalene. Catalyst: filtered solutions
of (RP)-5 or (SP)-5 + olefin + AgBF4, except for run 11, where compound 6 was used. c Conversion of starting olefin. Selectivity: % of
3-aryl-1-butene with respect to the hydrovinylation fraction (3-aryl-1-butene and 2-aryl-2-butenes). e C16-fraction: styrene dimers. f TOF/
h calculated as the total amount of arylbutenes formed.
d
The complex [Pd(η3-2-MeC3H4)(PBzCyPh)S]BF4, pre-
pared in situ from 5 and AgBF4 in CH2Cl2 solution, was
used as a catalyst for asymmetric hydrovinylation of
styrene and 2-vinylnaphthalene, and the results are
shown in Table 4. Optical rotation measurements show
that (-)-(R)-3-phenyl-1-butene and (-)-(R)-3-(2-naph-
thyl)-1-butene were obtained from (SP)-5. We should
emphasize the great activity of this catalyst (up to 1290
cycles per palladium atom and hour), the excellent
selectivity, the low amount of dimers formed (ranging
between 0.6 and 5.5%), and the ee values obtained, 60%
for 3-phenyl-1-butene and 85% for 2-(2-naphthyl)-1-
butene. It should also be noted that these results were
obtained in mild conditions of temperature (15 °C) and
ethylene pressure (15 bar).17,18
As can be seen in runs 1 and 2, the solvent has an
important role in the hydrovinylation reaction, influenc-
ing both activity and enantioselectivity. This suggests
that solvent molecules could be coordinated to the metal
atom in some steps of the catalytic cycle, stabilizing
species with low coordination numbers. One such step
(16) Keim, W.; Vogt, D.; Bayersdoerfer, R. DE 19,512,881, Aug 29,
1996; Chem. Abstr. 1996, 125, 248773t. Bayersdo¨rfer, R.; Ganter, B.;
Englert, U.; Keim, W.; Vogt, D. J . Organomet. Chem. 1998, 552, 187.

3516 Organometallics, Vol. 18, No. 17, 1999
Albert et al.
it contains. Cyclopalladated compounds 3, PBz2Ph, and [Pd-
(µ-Cl)(η3-2-MeC3H4)]2 were prepared according to procedures
described elsewhere.6,19,20
is the coordination of the styrene derivative to the metal
center, where the asymmetric induction is created. As
expected, the reactions in THF are slower than those
in dichloromethane, due to the higher donor properties
of tetrahydrofuran, which can compete strongly with the
olefins for the coordination to the palladium center.
We also tested a cationic complex as a catalyst
precursor. For this purpose we had synthesized the
complex 6, [Pd(η3-2-MeC3H4)(NCCH3)(PBzCyPh)]BF4.
This catalyst (run 11) presented lower activity than the
one generated in situ, probably due to the presence of
acetonitrile, which can compete with alkenes for the
coordination to the palladium atom.
Syn th esis of (()-Ben zylcycloh exylp h en ylp h osp h in e.
Small pieces of lithium (0.086 g, 12.4 mmol) were added to a
solution of dibenzylphenylphosphine (1.5 g, 5.17 mmol) in THF
(40 mL), and the reaction mixture was stirred for 20 h at 20
°C. The excess of lithium was removed by decantation,
cyclohexyl bromide (0.94 mL, 7.63 mmol) was added, and the
mixture was stirred for 10 min. The resulting solution was
washed twice in 10 mL of an aqueous solution of ammonium
chloride (15%) and concentrated in vacuo to afford (()-
benzylcyclohexylphenylphosphine as an oil, which can be
characterized by NMR spectroscopy. 31P (101.26 MHz): δ )
1
-6.13 s. H NMR (250 MHz, CDCl3): δ ) 7.52-7.48 (m, 2H,
The results obtained with this optically pure Horner
phosphine are of the same order as those obtained with
hemilabile P-chiral phosphines.3a,16 Active species con-
taining only one phosphine per metal atom and the
proximity of the stereogenic center to the metal can
explain this. The results of RajanBabu et al.15 using an
allyl-nickel system with functionalized phosphines with
the stereogenic center in the labile arm of the phosphine
may be related with the availability of the fifth coordi-
nation position in nickel complexes and its importance
in the control of the selectivity of the reaction. In
conclusion, phosphines such as benzylcyclohexylphe-
nylphosphine are good ligands for asymmetric homo-
geneous catalysis, and experiments testing this type of
phosphines in other catalytic reactions are currently in
progress.
aromatic), 7.20-7.05 (m, 8H, aromatic), 3.06 (dd, 1H, J ) 24.0,
J ) 13.5, CH2), 3.05 (dd, 1H, J ) 24.0, J ) 13.5, CH2), 1.95-
1.85 (m, 1H, aliphatic), 1.80-1.50 (m, 5H, aliphatic), 1.40-
1.10 (m, 5H, aliphatic). 13C NMR (75.4 MHz, CDCl3): δ )
138.35 (d, J ) 6.3 Hz, Bz), 136.22 (d, J ) 16.4 Hz, Ph), 133.60
(d, J ) 15.8 Hz, Ph), 129.11 (s, Ph), 128.9 (d, J ) 11.5 Hz,
Ph), 128.07 (s, Bz), 127.98 (d, J ) 5.7 Hz, Bz), 125.45 (s, Bz),
36.64 (d, J ) 11.6 Hz, Cy), 32.62 (d, J ) 16.5, CH2P), 29.69 (d,
J ) 15.2 Hz, Cy), 29.06 (d, J ) 11.0 Hz, Cy), 26.92 (d, J ) 11.0
Hz, Cy), 26.78 (d, J ) 9.2 Hz, Cy), 26.33(s, Cy).
Syn th esis of [NiCl2(P BzCyP h )2], 2. For the synthesis of
the coordination compound 2, a saturated solution of NiCl2 in
ethanol absolute (3 mL) was added to a THF solution of (()-
benzylcyclohexylphenylphosphine, and the resulting mixture
was stirred for 15 min and then concentrated in vacuo. Dark
red crystals of the complex were obtained, filtered, and dried.
The yield of the process was 60% (1.079 g). Anal. Calcd for
C
38H46Cl2NiP2: C, 65.73; H, 6.68. Found: C, 65.3; H, 6.6. MS-
positive FAB: 657 [(M - Cl)+].
Exp er im en ta l Section
Syn th esis of 4. A suspension formed by 0.24 mmol of 3,
0.24 mmol (165 mg) of dichlorobis[(()-benzylcyclohexylphe-
nylphosphine]nickel(II), and 30 mL of THF was stirred at room
temperature for 45 min, and the resulting solution was
concentrated in vacuo. The solid obtained was eluted by SiO2
column chromatography with CHCl3-acetone (100:4 for 4a ,
100:2 for 4b, and 100:4 for 4c) as eluent. Compounds (RC,RP)-4
and (RC,SP)-4 (1:1 mixture of diastereoisomers) were isolated
as yellow solids in a yield of 80-90%. Characterization data:
4a 31P (101.26 MHz, CDCl3): δ ) 39.03 s and 39.41 s. Anal.
Calcd for C27H33ClNPPd: C, 59.57; H, 6.11; N, 2.57. Found:
C, 59.5; H, 6.2; N, 2.5. 4b 31P (101.26 MHz, CDCl3): δ ) 47.3
and 43.3 s. Anal. Calcd for C29H37ClNPPd: C, 60.85; H, 6.51;
N, 2.45. Found: C, 61.0; H, 6.7; N, 2.5. 4c 31P (101.26 MHz,
Exp er im en ta l Section . 1H NMR at 200 MHz and 13C{1H}
at 50.3 MHz were recorded on a Varian Gemini 200 spectrom-
eter, and 1H NMR at 500 MHz, 13C NMR at 75.4 MHz, and
31P{1H} at 101.26 MHz were recorded, respectively, on a
Varian VXR 500, a Varian 300, and a Bruker DRX 250
spectrometer. Chemical shifts (in ppm) were measured relative
1
to SiMe4 for H and13C and to 85% H3PO4 for 31P. The solvents
used were CDCl3 in 1H and THF or CHCl3 in 31P. Microanaly-
ses were performed at the Institut de Qu´ımica Bio-Orga`nica
de Barcelona and the Serveis Cient´ıfico-Te`cnics de la Univer-
sitat de Barcelona. Infrared spectra were recorded as KBr
disks on a Nicolet 520 FT-IR spectrometer. GC analyses were
performed on a Hewlett-Packard 5890 series II chromatograph
equipped with a 50 m ultra-2 cross-linked 5% phenylmethyl
silicone capillary column and a FID detector connected to an
HP 3396A integrator. Mass spectra were obtained with a
Hewlett-Packard 5890 series II chromatograph with the same
column coupled to a Hewlett-Packard 5971A mass selective
detector. Enantiomeric excess was determined by GC analysis
with a Hewlett-Packard 5890 chromatograph fitted with a 25
m FS-CYCLODEX column. Helium was used as carrier gas
in all cases. The optical rotations of the complexes (c ) g/100
mL, in CHCl3) were determined at 20 °C using a Perkin-Elmer
241-MC polarimeter. Mass spectra were recorded on a Fisons
VG-Quattro spectrometer. The samples were introduced in a
matrix of 2-nitrobenzyl alcohol for FAB analysis and then
subjected to bombardment with cesium atoms.
CDCl3): δ ) 38.21 and 41.48 s. Anal. Calcd for C31H35
-
ClNPPd: C, 62.63; H, 5.93; N, 2.35. Found: C, 62.8; H, 5.8;
N, 2.3. MS-positive FAB: 595 [M+].
Sep a r a tion of 4a Dia ster eoisom er s. A 1:1 mixture of
diastereoisomers (RC,RP)-4a and (RC,SP)-4a (100 mg) was
carefully eluted at room temperature, in a SiO2 column (30 ×
400 mm, 30 g SiO2) with CHCl3-acetone (100:2) as eluent.
The second band eluted was collected in fractions of 15 mL,
1
concentrated in vacuo, and checked by H NMR spectroscopy.
1
The fractions of the optically pure compound (by 200 MHz H
NMR spectroscopy) were selected using the aromatic or the
methylic proton signals. The diastereoisomer (RC,RP)-4a was
obtained in 84% yield (42 mg), with a de higher than 90%.
Characterization data: (RC,RP)-4a 31P (101.26 MHz, CDCl3):
Ma ter ia ls a n d Syn th esis. All the reactions involving free
phosphines were carried out using Schlenk techniques under
nitrogen atmosphere. All solvents were dried and degassed by
standard methods. Tetrahydrofuran and toluene were distilled
over sodium benzophenone, under nitrogen, before use. CH2-
Cl2 was distilled over CaO-CaCl2. All chemical were of
commercial grade and used as received, except for 2-vinyl-
naphthalene, which was recrystallized from ethanol-water in
order to eliminate the small amount of 2-naphthaldehyde that
(17) It should be noted that reaction times longer than 30 min (at
15 °C) afford a yield near 100% (calculated as conversion of starting
olefin), but a significant decrease in the selectivity is also observed
(see entry 6).
(18) Small amounts of 2-vinylnaphthalene dimers were observed,
but not significantly bigger than those contained in the recrystallized
product used as starting material.
(19) Browning, M. C.; Mellor, J . R.; Morgan, D. J .; Pratt, S. A. J .;
Sutton, L. E.; Venanzi, L. M. J . Chem. Soc. 1962, 693.
(20) Tatsuno, Y.; Yoshida, T.; Otsuka, S. Inorg. Synth. 1990, 28, 342.

Resolution of Benzylcyclohexylphenylphosphine
Organometallics, Vol. 18, No. 17, 1999 3517
1
δ ) 39.03, s. H NMR (500 MHz, CDCl3): δ ) 7.45-7.35 (m,
s. 1H NMR (200 MHz, CDCl3): δ ) 7.40-7.31 (m, 10H, Ar),
7.08 (m, 6H, Ar), 7.00-6.95 (m, 4H, Ar), 4.45 (m, J HH ) 3.5
Hz, J PH ) 6.5 Hz, 2H, Ha), 3.65-3.48 (m, 4H, CH2), 3.44 (dd,
J PH ) 10 Hz, 2H, Hb), 2.95 (s, 1H, Hc) 2.89 (s, 1H, Hc), 2.44 (s,
1H, Hd) 2.03 (s, 1H, Hd), 2.26-1.07 (m, 22H, aliphatic), 1.86
(s, 3H, Me), 1.76 (s, 3H, Me). MS-positive FAB: 443 [(M -
Cl)+].
3H, aromatic), 7.30-7.20 (m, 2H, aromatic), 7.20-7.00 (br m,
5H, aromatic), 7.00-6.80 (m, 2H, H3, H4), 6.40 (t, J HH ) 7.5
3
Hz, 1H, H2), 6.19, (m, 1H, H1), 4.45 (m, 1H, HCMe), 3.96 (br
m, 1H, NH), 3.5-3.8 (m, 2H, CH2), 3.36 (br m, 1H, NH), 2.30-
3
1.25 (m, 11H, aliphatic.), 1.71 (d, J HH ) 6.6 Hz, 3H, Me).
(RC,SP)-4a : 31P (101.26 MHz, CDCl3,): δ ) 39.41, s. H NMR
1
Syn th esis of [P d (η3-2-MeC3H4)Cl(P BzCyP h )], 5 (Con -
ta in in g Op tica lly P u r e P h osp h in e). A 0.16 mmol (0.067 g)
sample of 1,2-bis(diphenylphosphino)ethane (dppe) was added
to a solution of (RC,SP)-4c or (RC,RP)-4c (0.16 mmol) in ether
(30 mL), and the mixture was stirred under nitrogen for 15
min at room temperature. A 33.5 mg (0.084 mmol) sample of
[Pd(µ-Cl)(η3-2-MeC3H4)]2 was added to the resulting suspen-
sion, and the mixture was stirred for 30 min at room temper-
ature and then concentrated in vacuo. The solid obtained was
eluted by SiO2 column chromatography with CHCl3-acetone
(100:3) as eluent. Compound 5, containing optically pure
phosphine, was isolated as a yellow solid in a yield of 85% (65
mg). Optical rotation, (SP)-[Pd(η3-2-MeC3H4)Cl(PBzCyPh)]:
[R]20D) -22.2° cm2 g-1 (c ) 0.55).
(500 MHz, CDCl3): 7.40-7.30 (m, 3H, aromatic), 7.30-7.20
(m, 2H, aromatic), 7.20-7.00 (br m, 5H, aromatic), 6.90-6.80
3
(m, 2H, H3, H4), 6.37 (t, J HH)7.5 Hz, 1H, H2), 6.08 (m, 1H,
H1), 4.45, (m, 1H, HCMe), 3.96 (br m, 1H, NH), 3.6-3.8 (m,
2H, CH2), 3.35 (br m, 1H, NH), 2.3-1.25 (m, 11H, aliphatic),
3
1.71 (d, J HH ) 6.6 Hz, 3H, Me).
Sep a r a tion of 4b Dia ster eoisom er s. A 1:1 mixture of
diastereoisomers (RC,RP)-4b and (RC,SP)-4b (100 mg) was
dissolved in ether at room temperature, and the solution was
cooled to 4 °C. A crystalline fraction of (RC,SP)-4b was obtained
in 70% yield (35 mg), with a de higher than 95%. Character-
ization data: (RC,RP)-4b 31P (101.26 MHz, CDCl3): δ ) 43.3,
s. 1H NMR (500 MHz, CDCl3): δ ) 7.60-7.00 (br m, 10H,
3
3
aromatic), 6.83 (d, J HH ) 7.5 Hz, 1H, H4), 6.66 (t, J HH ) 7.5
Hz, 1H, H3), 6.29 (t, 3J HH ) 7.5 Hz, 1H, H2), 5.93 (t, 3J HH ) 7.5
Hz, 1H, H1), 3.79-3.94 (m, 2H, CH2), 3.50 (br m, 1H, HCMe),
Syn t h esis of [P d (η3-2-MeC3H 4)(NCCH 3)(P BzCyP h )]-
[BF 4], 6. A few drops of acetonitrile and 0.104 g (0.53 mmol)
of AgBF4 were added to a solution of 5, 0.240 g (0.50 mmol) in
25 mL of THF. The mixture was stirred for 15 min in the
darkness, and the AgCl formed was filtered off through Celite.
The resulting solution was concentrated, and the addition of
ether caused the precipitation of a white solid (6), which was
separated by filtration. Yield: 0.185 g (0.32 mmol, 65%).
Characterization data for 6: Anal. Calcd for C25H33BF4NPPd:
C, 52.52; H, 5.82; N, 2.45. Found: C, 52.3; H, 5.9; N, 2.6. 31P
(101.26 MHz, CDCl3): δ ) 34.1 s and 33.0 s. 1H NMR (200
MHz, CDCl3): δ ) 7.52-7.40 (m, 10H, aromatic), 7.22-7.14
(m, 6H, aromatic), 7.05-6.95 (m, 4H, aromatic), 4.90 (dd, J HH
) 3.0 Hz, J PH ) 5.0 Hz, 1H, Ha), 4.85 (dd, J HH ) 3.0 Hz, J PH
) 5.0 Hz, 1H, Ha), 3.65-3.46 (m, 6H, CH2, Hb), 3.05 (s, 1H,
Hc) 2.98 (s, 1H, Hc), 2.32 (s, 1H, Hd), 2.29 (s, 6H, NCCH3), 2.17
(s, 1H, Hd), 2.35-0.90 (m, 22H, aliphatic), 1.90 (s, 3H, Me),
1.69 (s, 3H, Me).
3
3
2.67 (d, J HH ) 1.6 Hz, 3H, NMe), 2.61 (d, J HH ) 1.6 Hz, 3H,
3
NMe), 2.30-1.25 (m, 11H, aliphatic.), 1.63 (d, J HH ) 6.6 Hz,
3H, Me). (RC,SP)-4b 31P (101.26 MHz, CDCl3): δ ) 47.3, s. H
1
NMR (500 MHz, CDCl3): δ ) 7.60-7.00 (br m, 10H, aromatic),
6.90-6.70 (m, 2H, aromatic), 6.12 (t, J HH ) 7.5 Hz, 1H, H2),
3
5.50 (t, J HH ) 7.5 Hz, 1H, H1), 3.70-3.80 (m, 2H, CH2), 3.50
3
3
(br m, 1H, HCMe), 2.78 (d, J HH ) 1.6 Hz, 3H, NMe), 2.64 (d,
3J HH ) 1.6 Hz, 3H, NMe), 2.30-1.25 (m, 11H, aliphatic), 1.80
3
(d, J HH ) 6.6 Hz, 3H, Me).
Sep a r a tion of 4c Dia ster eoisom er s. A 1:1 mixture of
diastereoisomers (RC,RP)-4c and (RC,SP)-4c (100 mg) was
carefully eluted at room temperature, in a SiO2 column (30 ×
400 mm, 50 g SiO2) with CHCl3-acetone (100:3) as eluent.
The first band eluted was collected in fractions of 25 mL,
1
concentrated in vacuo, and checked by H NMR spectroscopy.
1
The fractions of the optically pure compound (by 200 MHz H
NMR spectroscopy) were selected using the aromatic or the
methylic proton signals. The diastereoisomers (RC,RP)-4c and
(RC,SP)-4c were obtained in 70% (35 mg) and 66% (33 mg)
yield, respectively, with a de higher than 95% in both cases.
Characterization data: (RC,RP)-4c 1H NMR (500 MHz,
CDCl3): δ ) 7.60 (d, J HH ) 8.5 Hz, 1H, aromatic), 7.50 (d, J HH
) 7.5 Hz, 1H, aromatic), 7.35-7.20 (m, 5H, aromatic), 7.10
(m, 2H, aromatic), 7.06 (m, 3H, aromatic), 6.91 (m, 3H,
aromatic), 6.48 (dd, J HH ) 9 Hz, J PH ) 5 Hz, 1H, H1), 5.2 (m,
J HH ) 5.5 Hz, 1H, HCMe), 4.05 (br, 1H, NH), 3.88 (m, 1H,
CH2), 3.56 (br, 1H, NH), 3.54 (m, 1H, CH2), 2.35-1.25 (m, 11H,
aliphatic), 1.95 (d, J HH ) 6.5 Hz, 3H, Me).31P (101.26 MHz,
CDCl3): δ ) 38.3, s. Optical rotation: [R]20D) +6.72° cm2 g-1
Hyd r ovin yla tion Rea ction s. Hydrovinylation reactions
were performed in a stainless steel autoclave fitted with an
external jacket connected to a thermostated isobutanol bath
controlled to (0.5 °C; internal temperature and pressure as a
function of time were registered with a Linseis L-200 recorder.
-2
A mixture of 5 (20.0 mg, 4.17 × 10
mmol), AgBF4 (8.9 mg,
4.57 × 10-2 mmol), and styrene (4.34 g, 0.0417 mol) in 10 mL
of dry CH2Cl2 was stirred for 5 min in the darkness. After
filtering off the AgCl formed the solution was placed in the
autoclave and thermostated at the desired temperature, and
ethylene was admitted until a pressure of 15 bar was reached.
After the time indicated in Table 4 for every reaction, the
autoclave was slowly depressurized and 10% HCl (10 mL) was
added, and the mixture was stirred for 10 min in order to
quench the catalyst. The CH2Cl2 layer was decanted off and
dried with Na2SO4. The quantitative distribution and ee of the
products were determined by GC analysis. Major components
1
(c ) 1). (RC,SP)-4c H NMR (500 MHz, CDCl3): δ ) 7.64-7.46
(m, 5H, aromatic), 7.30-7.12 (m, 9H, aromatic), 6.70 (d, J HH
3
) 8.4 Hz, 1H, H2), 6.05 (dd, J HH ) 8.6 Hz, J PH ) 5.2 Hz, 1H,
3
H1), 5.2 (m, J HH ) 5.6 Hz, 1H, HCMe), 3.98-3.85 (br, 2H,
1
NH, CH2), 3.72-3,49 (br, 2H, NH, CH2), 2.63-0.8 (m, 11H,
were characterized by H NMR.
3
aliphatic), 1.98 (d, J HH ) 6.2 Hz, 3H, Me).31P (101.26 MHz,
Ch ar acter ization of Hydr ovin ylation P r odu cts. 3-Phen-
yl-1-butene: 1H NMR (200 MHz, CDCl3): δ ) 1.36 (d, J ) 7.0
Hz, 1H), 3.47 (m, 1H), 5.03 (dd, J ) 10.5 Hz, J ) 1.4 Hz, 1H),
5.05 (dd, J ) 17.0 Hz, J ) 1.4 Hz, 1H), 6.01 (ddd, J ) 17.0 Hz,
J ) 10.5 Hz, J ) 6.8 Hz, 1H), 7.10-7.35 (m, 5H). 13C NMR
(50.3 MHz, CDCl3): δ ) 20.7, 43.2, 113.1, 126.1, 127.2, 128.4,
143.2, 145.5. cis-2-Phenyl-2-butene: 1H NMR (200 MHz,
CDCl3): δ ) 1.77 (d, J ) 6.9 Hz, 3H), 2.01 (s, 3H), 5.85 (q, J
) 6.9 Hz, 1H), 7.10-7.40 (m, 5H). 13C NMR (50.3 MHz,
CDCl3): δ ) 14.3, 15.4, 122.4, 125.5, 126.4, 128.1, 135.5, 144.0.
3-(2-Naphthyl)-1-butene: 1H NMR (200 MHz, CDCl3): δ ) 1.45
(d, J ) 7.0 Hz, 1H), 3.63 (m, 1H), 5.12 (m, 2H), 6.08 (ddd, J )
17.2, J ) 10.5 Hz, J ) 1.4 Hz, 1H), 7.20-7.95 (m, 7H). cis-2-
(2-Naphthyl)-2-butene: 1H NMR (200 MHz, CDCl3): δ ) 1.63
CDCl3): δ ) 41.4, s. Optical rotation: [R]20D) +41.23° cm2 g-1
(c ) 1).
Syn th esis of [P d (η3-2-MeC3H4)Cl(P BzCyP h )], 5 (Con -
ta in in g Ra cem ic P h osp h in e). A 100 mg (0.144 mmol)
sample of dichlorobis[(()-benzylcyclohexylphenylphosphine]-
nickel(II) and 57 mg (0.144 mmol) of [Pd(µ-Cl)(η3-2-MeC3H4)]2
were stirred for 30 min in toluene (30 mL). The mixture was
then concentrated to dryness, and the product was purified
by SiO2 column chromatography with CHCl3-acetone (100:3)
as eluent. A 111 mg (0.23 mmol) sample of compound 5 was
isolated as a yellow solid. Yield: 81%. Characterization data
for 5: Anal. Calcd for C23H30ClPPd: C, 57.63; H, 6.30. Found:
C, 57.7; H, 6.3. 31P (101.26 MHz, CDCl3): δ ) 33.5 s and 32.3

3518 Organometallics, Vol. 18, No. 17, 1999
Albert et al.
Ta ble 5. Su m m a r y for Cr ysta l Da ta a n d Str u ctu r e
An a lysis
1-butene (He flow: 2.10 mL/min, 100 °C), retention times:
R-isomer, 38.7 min; S-isomer, 39.7 min. The assignment of the
absolute configuration of the major enantiomers was per-
formed by measuring the optical rotation of a reaction mixture
and comparison of the sign of the obtained value with
literature values.21
(RC,SP)-4b
5
formula
fw
C
29H37ClNPPd
C23H30ClPPd
479.32
572.44
crystal Size (mm)
color, shape
cell measurements
(24 ref)
0.38 × 0.35 × 0.08 0.30 × 0.20 × 0.06
yellow, plate yellow-plate, prism
12.7° < 2θ < 15.3° 13.9° < 2θ < 18.4°
Cr ystallogr aph ic Stu dies. A yellow plate crystal of (RC,SP)-
4b (0.35 × 0.08 × 0.38 mm) or 5 (0.20 × 0.06 × 0.30 mm) was
selected, mounted on a glass fiber, and transferred to a Rigaku
AFC6S diffractometer. Graphite-monochromatized Mo KR
radiation was used. Cell constants were obtained from a least-
squares refinement using the setting angles of 25 carefully
centered reflections. The system was determined to be orthor-
hombic, space group P212121 (acentric) for (RC,SP)-4b and
monoclinic, space group P21/n (No. 14) for 5. The data were
collected using the ω-2θ scan method. The intensities of three
standard reflections were measured after 100 reflections to
apply the decay correction. Lorentz-polarization and absorp-
tion corrections (DIFABS method) were also applied. A sum-
mary of experimental details is given in Table 5. The struc-
tures were solved by the Patterson method. Hydrogen atoms
in the π-allyl ligand were found in a difference Fourier map,
and the others were included in calculated positions and not
refined. Final values of R ) 0.044 and Rw ) 0.053 were
obtained for (RC,SP)-4b and final values of R ) 0.049 and Rw
) 0.064 were obtained for 5. All calculations were carried out
using the TEXSAN software package on a VAX 3520 computer
at the “Servicio Central de Ciencia y Tecnologia de la Univer-
sidad de Ca´diz”.22
crystal system
space group
cell params
orthorhombic
monoclinic
P21/n (No. 14)
a ) 14.6206) Å
b ) 17.149(6) Å
c ) 9.669(6) Å
â ) 90.17°
2424(3) Å3
4
P212121 (No. 19)
a ) 16.497(6) Å
b ) 16.928(5) Å
c ) 9.795(6) Å
volume
Z
density (calcd)
λ(Mo KR)
µ(Mo KR)
F(000)
2735(2) Å3
4
1.390 g cm-3
0.71069 Å
8.42 cm-1
1184.00
1.313 g cm-3
0.71069 Å
9.35 cm-1
984
abs corr
DIFABS
DIFABS
transmission factors
standards number,
interval
0.837-1.148
3 ref, 100 ref
0.829-1.168
3 ref, 100 ref
decay (%)
-2.40
-6.70
temperature
scan method
scan speed (ω)
2θ interval
290(1) K
ω/2θ
290(1) K
ω/2θ
4° min-1
5° < 2θ < 50.1°
4° min-1
5° < 2θ < 50.1°
3945
no. of measured reflns 2439
no. of unique reflns
no. of obsd reflns
(I > 3σ)
2439
1634
3945
2526
Ack n ow led gm en t. This work was supported by the
DGICYT and CIRIT (project: PB 96-0164 and QFN95-
4708) and by the Comissionat per a Universitats i
Recerca (project: 1997SGR 00174). J .M.C. thanks the
Agencia Espan˜ola de Cooperacio´n Internacional for a
fellowship.
no. of params
refln/param ratio
refinements
Ra
203
8.05
235
10.75
full-matrix ls on F Full-matrix ls on F
0.0441
0.0526
1.506
0.0485
0.0636
1.987
+1.25, -0.62
-2
b
Rw (w ) σF
)
gof
residual peaks (e/Å3)
+0.36, -0.43
Su p p or tin g In for m a tion Ava ila ble: Crystallographic
data (excluding structure factors) for (RC, SP)-4b and 5. This
material is available free of charge via the Internet at
http://pubs.acs.org
R ) ∑(|Fo| - |Fc|)/∑(|Fo|. Rw ) [(∑w(|Fo| - |Fc|)2/∑wFo2)]1/2
.
a
b
(d, J ) 6.3 Hz, 3H), 1.92 (s, 3H), 5.82 (m, 1H), 7.00-7.80 (m,
7H). 13C NMR (50.3 MHz, CDCl3): δ ) 14.4, 15.3, 123.0, 123.7,
124.2, 125.2, 125.8, 127.4, 127.5, 127.9, 129.4, 132.6, 133.5,
141.0.
The ee of the products was determined by GC analysis.
3-Phenyl-1-butene (He flow: 2.10 mL/min, 60 °C), retention
times: R-isomer, 8.0 min; S-isomer, 8.2 min. 3-(2-Naphthyl)-
OM990302D
(21) (a) Lardicci, L.; Salvadori, P.; Caporusso, A. M.; Menicagli, R.;
Belgodere, E. Gazz. Chim. Ital. 1972, 102, 35. (b) Menicagli, R.; Piccolo,
O.; Lardicci, L.; Wis, M. L. Tetrahedron 1979, 35, 1301.
(22) TEXSAN, Single-Crystal Structure Analysis Software, Version
5.0; Molecular Structure Corp.: TX, 1989.