Asymmetric hydroformylation catalyzed by rhodium(I) complexes of novel chiral spiro ligands

Article abstract of DOI:10.1016/S0022-328X(99)00257-0

Chiral diphosphites and phosphinite-phosphites derived from spiro[4.4]nonane-1,6-diol were synthesized. Using Rh[I]-7 complex in asymmetric hydroformylation of styrene, high regioselectivity (97%) and moderate enantioselectivity (65% ee) have been obtained. This catalyst system was also effective for aryl-substituted olefins. The diphosphites 8 and 9 bearing 1,1′-binaphthyl backbones were tested and the opposite configuration of the product indicates that the sense of enantioface selection is mainly dictated by the configuration of the terminal groups. Phosphinite-phosphite ligands gave low enantiomeric excesses (up to 48% ee) and low b/n ratios. These results suggest that the regio- and enantioselectivity is mainly affected by the bulky substituents on terminal groups. The crystal structure of Rh(7)(acac) are presented. The distortion in the structure is indicative of a crowded rhodium center.

Full text of DOI:10.1016/S0022-328X(99)00257-0

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 586 (1999) 159–165
Asymmetric hydroformylation catalyzed by rhodium(I) complexes
of novel chiral spiro ligands
Yaozhong Jiang a, Song Xue a,*, Kaibai Yu a, Zhi Li a, Jingen Deng a, Aiqiao Mi a,
Albert S.C. Chan b
a Chengdu Institute of Organic Chemistry, Academia Sinica, Chengdu 610041, PR China
b Hong Kong Polytechnic Uni6ersity, Hong Kong, PR China
Received 2 February 1999; received in revised form 27 April 1999
Abstract
Chiral diphosphites and phosphinite-phosphites derived from spiro[4.4]nonane-1,6-diol were synthesized. Using Rh[I]–7
complex in asymmetric hydroformylation of styrene, high regioselectivity (97%) and moderate enantioselectivity (65% ee) have
been obtained. This catalyst system was also effective for aryl-substituted olefins. The diphosphites 8 and 9 bearing 1,1%-binaphthyl
backbones were tested and the opposite configuration of the product indicates that the sense of enantioface selection is mainly
dictated by the configuration of the terminal groups. Phosphinite–phosphite ligands gave low enantiomeric excesses (up to 48%
ee) and low b/n ratios. These results suggest that the regio- and enantioselectivity is mainly affected by the bulky substituents on
terminal groups. The crystal structure of Rh(7)(acac) are presented. The distortion in the structure is indicative of a crowded
rhodium center. © 1999 Elsevier Science S.A. All rights reserved.
Keywords: Hydroformylation; Chirality; Spiro ligands; X-ray structure
Recently, we have synthesized novel chiral diphos-
phite ligands derived from cis,trans-spiro[4.4]nonane-
1,6-diol (abbreviated spirol) and used them for the
Rh(I)-catalyzed asymmetric hydroformylation of
styrene [14]. These diphosphite–Rh(I) catalyst systems
show moderate enantioselectivities and high regiose-
lectivities in styrene and its derivatives. We sought to
extend our studies to other ligands containing spiro
backbone. Diphosphites containing a chiral centre in
the spiro backbone and a chiral axis in the terminal
groups were prepared for their cooperativity, since
chiral cooperative effects have been observed in
rhodium and platinum catalyzed asymmetric hydro-
formylation [13,15,16]. Bisphosphinite derived from
cis,cis-spirol was found to be an efficient chiral ligand
for the catalytic asymmetric hydrogenation of enam-
ides [17]. Here, we also wish to report the synthesis
of phosphinite–phosphite ligands derived from cis,cis-
spirol and their catalytic properties in the asymmetric
hydroformylation of styrene.
1. Introduction
Catalytic asymmetric hydroformylation of olefins is
a process of great interest for the preparation of opti-
cally pure aldehydes, useful for the synthesis of many
biologically active compounds [1]. Platinum–tin and
rhodium catalysts modified by chiral phosphines and
diphosphines have been mostly used as the catalysts
[2–4]. Since van Leeuwen [5] reported high catalytic
activity of bulky phosphite ligands in rhodium-cata-
lyzed hydroformylation, there has been growing inter-
est in the use of these ligands [6–10]. Up to now, the
highest enantioselectivity in an asymmetric hydro-
formylation of olefins was obtained with the phos-
phine–phosphite ligands reported by Nozaki and
coworkers [11–13].
* Corresponding author.
E-mail address: ulas@netease.com (S. Xue)
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(99)00257-0

160
Y. Jiang et al. / Journal of Organometallic Chemistry 586 (1999) 159–165
Scheme 1.
Scheme 3.
Scheme 2.
Scheme 4.
2. Results and discussion
ties of compounds 6–11 containing rhodium have been
evaluated in the asymmetric hydroformylation of
styrene (12a) and its derivatives (12b–d) (Scheme 4).
The catalyst species were prepared in situ by simply
mixing Rh(acac)(CO)2 and 1.5 equivalents of the lig-
ands. A little excess of ligands is useful for preventing
the reaction catalyzed by unmodified rhodium species
[13,20]. An incubation period is necessary for the for-
mation of Rh(L)(CO)2 from Rh(acac)(CO)2 and
diphosphites [7,21]. In order to increase the reaction
rate, the catalyst was prepared under typical conditions
[40°C, 10 atm of syn gas, 10 h] before substrate was
added. The results are summarized in Table 1.
A high yield of aldehyde (89%) and moderate enan-
tioselectivity (62% ee) were achieved in toluene under
CO/H2=5/5 atm, at 40°C for 10 h (run 1). As a
solvent, CH2Cl2, cyclohexene and THF gave compara-
ble ee values of the product, but they resulted in a low
yield of aldehyde (runs 2–4). Compounds 6–11 were
also evaluated under the typical hydroformylation reac-
tion conditions [40°C, 20 atm, 10 h]. Compound 6, in
which the bis(phenol) moiety is substituted with tert-
butyl group at para position, showed relatively high
catalytic activity and gave 92% yield of aldehyde (run
6). The enantioselectivity is slightly lower than that
found in compound 7 (run 5 versus 6), which might be
2.1. Synthesis
Spirol has three diastereomers (Fig. 1). We have
successfully synthesized cis,cis-spirol and cis,trans-
spirol by stereoselectively reduction of spiro[4.4]-
nonane-1,6-dione with lithium n-butyldiisobutylalu-
minium hydride and BH3·THF [18], respectively. The
optically pure cis,cis-spirol and cis,trans-spirol were
used as starting materials for the synthesis of our chiral
ligands.
Compounds 6 and 7 have been synthesized by the
reaction of (1R,5R,6S)-cis,trans-spirol 2 with the corre-
sponding chlorophosphites 4 in benzene in the presence
of pyridine [14] (Scheme 1). Compounds 8 and 9 have
also been prepared by mixing the (1R,5R,6S)-cis,trans-
spirol 2 with the chlorophosphites (S)-5a or (R)-5b,
respectively (Scheme 2) and they contain axial as well
as central chirality. This pair of diastereomers, as less
electron-rich diphosphites, may cause dramatic changes
in the reactivity and selectivity. However, when
(1R,5R,6R)-cis,cis-spirol 1 was treated with chloro-
phosphites 4 at the same procedure, diphosphites can-
not be obtained, and that may be attributed to the
steric constraints between the bulky substituents on
bi(phenol) moieties. Thus, phosphinite–phosphite lig-
ands were synthesized in benzene in the presence of
NEt3 (Scheme 3).
2.2. Catalysis
The aldehyde derived from aryl-substituted olefins
can be converted to various pharmaceuticals such as
antiinflammatory agents [19,20]. The catalytic proper-
Fig. 1. Three diastereomers of spiro[4.4]nonane-1,6-diol.

Y. Jiang et al. / Journal of Organometallic Chemistry 586 (1999) 159–165
161
due to electronic effects on the phosphorus atom. Com-
pounds 8 and 9, a pair of diastereomers, showed consid-
erably lower catalytic activity and b/n ratios.
Enantiomeric excess decreased markedly and the oppo-
site configuration of product was obtained (runs 8 and
9). The cooperative effect between central and axial
chiralty was not observed in these two diphosphites.
Diastereomers differing in the configuration of the termi-
nal groups afforded the opposite prevailing enantiomer
in the product and this implies that enantioselection is
dictated by the terminal groups. These results show that
the catalytic efficacy of diphosphite–Rh[I] complex is
mainly controlled by the large bulky substituents of the
terminal group and/or the increase of the electron density
on the phosphorus atom. Compounds 10 and 11 derived
from (1R,5R,6R)-cis,cis-spirol gave low catalytic activity
and selectivity compared to compounds 6 and 7. High
yield of aldehyde was obtained when the pressure of syn
gas was decreased, but this resulted in the loss of the ee
value (run 10 versus 11). Hydroformylations of para-sub-
stituted styrene derivatives 12b–d with the Rh(acac)-
(CO)2–7 catalyst system also gave aldehydes in high
regioselectivities and moderate enantioselectivities (runs
15–17).
2 shows the molecular structure and the adopted number-
ing scheme. Table 2 lists atomic coordinates and Table
3 gives selected bond lengths and bond angles. The figure
shows a square plannar surrounded rhodium. The P(1)–
Rh–P(2) angle of 96.69(5)° is large compared to the
analogous triphenyl phosphite complex [22] (94.8(2)°)
and demonstrates the steric hindrance of the diphosphite.
The enlarged P–Rh–P angle of 97.5(1)° [23] and
99.87(3)° [24] have been observed for Rh(acac)P2. The
decreased P(1)–Rh–P(2) bond angle in Rh(7)(acac) is
ascribed to the rigidity of spiro cycle and the eight-mem-
bered metallacycle. The metal–phosphorus bonds (P(1)–
,
,
Rh=2.1586(14) A; P(2)–Rh=2.168(2) A) are similar to
those found in the previously reported complexes con-
taining phosphites [23,24]. The O(1)–Rh–O(2) angle of
89.7(2)° is somewhat larger than that in the reported
literature (87.2(3)°) [23]. The distortion is also noticeable
from the various P–O–C angles. A study of P–O–C
angles of Cr(CO)5L complexes (L=phosphite) [25] re-
vealed that the average angles in this complex increased
with increasing bulkiness of the phosphite with a maxi-
mum of 127.5° for P(O-t-Bu)3 as ligand. In Rh(7)(acac)
the P(1)–O(6)–C(26) angle of 132.7(4)° is determined,
meaning that steric hindance has led to distortions within
the diphosphite. The P(1)–O(4)–C(4) angle of 128.2(4)°
is larger than the angle of P(2)–O(3)–C(9) (119.0(3)°),
thus indicating that the two terminal groups induce
different hindance, and O(4) atom is at cis position of
spiro cycle and O(3) at trans position. A analysis of
transition metal complexes of bis(diphenylphosphenyl)-
ethane type ligands shows the phenyl rings prefer
2.3. Crystal structure of Rh(7)(acac)
Slow crystallization from toluene of Rh(7)(acac) com-
plex afforded pale yellow crystals which proved to be
suitable for X-ray investigation. Data were collected on
a crystal of Rh(7)(acac), as summarized in Table 4. Fig.
Table 1
Asymmetric hydroformylation of styrene and its derivatives 12 catalyzed by Rh[I] complexes a
b
Run
Substrate
Ligand
Solvent
P (atm)
Yield (%) b
b/n
ee% c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
12a
7
7
7
7
7
6
8
9
Toluene
CH2Cl2
Cyclohexane
THF
10
10
10
10
20
20
20
20
10
20
10
20
20
20
20
20
20
89
66
62
63
85
92
74
34
61
45
81
67
40
61
71
63
85
97/3
96/4
97/3
96/4
97/3
98/2
80/20
81/19
82/18
84/16
83/17
82/18
84/16
85/15
96/4
62(S)
64(S)
60(S)
61(S)
65(S)
59(S)
29(S)
24(R)
24(R)
42(S)
31(S)
48(S)
38(S)
26(S)
63(+)
65(+)
70(+)
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Cyclohexane
CH2Cl2
Toluene
Toluene
Toluene
Toluene
9
10
10
10
10
11
7
12b
12c
12d
7
7
96/4
97/3
a Reactions were carried out in a 40 ml autoclave under the reaction conditions [syn gas (CO/H2=1/1), S/C=500, 40°C; L/Rh=1.5]. The
complex was incubated under 10 atm of syn gas at 40°C for 10 h before substrate was added.
b Yields and b/n ratios were determined by GC (b-236 M, 0.25 mm×25 m) using cis-decahydronaphthalene as an internal standard.
c Enantiomeric excesses were determined by GC analysis (b-236M, 0.25 mm×25 m) of the corresponding acid. Optical rotations or absolute
configurations are drawn in parentheses.

162
Y. Jiang et al. / Journal of Organometallic Chemistry 586 (1999) 159–165
Fig. 2. The structure of Rh(7)(acac). Hydrogen atoms and the minor disorder contribution were left out for clarity.
tert-butyl-4,4%-dimethoxy-2,2%-bis(phenol) were pre-
pared according to literature procedures [27,28].
Compounds 6 and 7 were synthesized as in the reported
literature [14]. Melting points were determined on
Southend SS25PH apparatus and are uncorrected. Ele-
mental analyses were recorded on a Carlo Erba-1106
instrument. Gas chromatographic analyses were per-
formed by SC-7 gas chromagraphy. 31P-NMR spectra
were obtained on a Varian FT-80A using H3PO4 (85%)
as an internal standard and 1H-NMR spectra on a
Bruker 300 spectrometer. Optical rotations were mea-
sured on a Perkin–Elmer 241 polarimeter. Enan-
tiomeric excesses were measured after Jones oxidation
of the aldehyde to the corresponding acids on a SC-7
gas chromatograph with a Chrompack b-236M, 0.25×
25 m chiral capillary column. Hydroformylation reac-
certain oritentation depending on their axial or equato-
rial position and the ligand chirality [26]. When the
Rh(7)(acac) complex is viewed from the observer (Fig.
3), two tert-butyl groups are above the plane defined by
P(1)–Rh–P(2) and two others under the plane. Differ-
ent dihedral angles of the two bis(phenol) moieties were
observed, 41.4° for C(15)–C(20)–C(21)–C(26) and
47.1° for C(37)–C(42)–C(43)–C(48). The bis(phenol)
moiety at cis position shows higher twisting resistance.
The chiral spiro cycle controls the orientations of the
four phenyl rings and tert-butyl groups, which form a
chiral array responsible for the regio- and enantioselec-
tivity in hydroformylation. Compound 8 containing
(S)-binaphthyl backbone showed higher catalytic activ-
ity in hydroformylation of styrene than compound 9
containing (R)-binaphthyl backbone and also gave the
production of the same configuration of compound 7.
These results might imply that the configuration of
(S)-binaphthyl backbone accords with the orientation
of bis(phenol) moiety in Rh[I]–7 complex.
tions were carried out in
stainless-steel autoclave (40 ml).
a
laboratory-made
3.2. Synthesis of 8 and 9
(S)-1,1%-Dinaphthol (305 mg, 1.2 mmol) dried under
reduced pressure at 80°C for 30 min was dissolved in
benzene (10 ml) and pyridine (0.4 ml). This solution
was added dropwise to a cooled solution (0°C) of PCl3
(0.2 ml) and pyridine (0.1 ml). The reaction mixture
was stirred for 6 h at 60°C. The solvent and excess of
PCl3 were removed under vacuum. The last trace of
PCl3 in the residue was removed by benzene (3 ml)
under reduced pressure and this procedure was repeated
three times. Compound 5a formed in situ was dissolved
in benzene (10 ml) and pyridine (0.5 ml). (1R,5R,6S)-
(cis,trans)-spiro[4.4]nonane-1,6-diol (78 mg, 0.5 mmol)
3. Experimental
3.1. General
All reactions were carried out in oven-dried glass-
ware using Schlenk techniques under pure nitrogen.
Benzene and toluene were distilled from sodium-ben-
zophenone, pyridine from CaH2. PCl3 and styrene were
distilled before use and stored under pure nitrogen.
4,4%,6,6%-Tetra-tert-butyl-2,2%-bis(phenol) and 6,6%-di-

Y. Jiang et al. / Journal of Organometallic Chemistry 586 (1999) 159–165
163
dissolved in benzene was added dropwise to the solu-
3.3. Synthesis of 10 and 11
tion of compound 5a at 0°C. The reaction mixture was
stirred overnight at room temperature. The resulting
pyridine salts were filtered off. Evaporation of the
solvent gave a white plaster that was purified by flash
column chromatography using toluene as eluent. White
solid (243 mg, 62%) was obtained. [h]2D0= −720.4°
(1R,5R,6R)-(cis,cis)-spiro[4.4]nonane-1,6-diol
(110
mg, 0.7 mmol) was dissolved in benzene (10 ml) and
NEt3 (1 ml). A stock solution of 4a in benzene (2.6 ml,
0.3 mol dm−1) was added and stirred for 6 h. Then
ClPPh2 (0.15 ml) was added dropwise to this solution at
0°C. The reaction mixture was stirred overnight at
room temperature and the salts formed were filtered
off. Evaporation of the solvent gave a white paste that
was purified by flash column chromatography using
toluene as eluent. White solid (216 mg, 40%) was
obtained. [h]2D0= −34.0° (0.37, toluene); m.p.=58−
59°C; 31P-NMR (CD3COCD3, l) 145.67, 101.81 ppm;
1H-NMR (CD3COCD3, l) 7.56–7.13 (m, 14H), 4.69
(m, 1H), 4.37 (m, 1H), 1.92–1.15 (m, 48H). Anal. Calc.
for C49H64O4P2: C, 75.55; H, 8.28. Found: C, 75.08; H,
8.17. Compound 11 was similarly prepared and white
(0.25,
toluene);
m.p.=142–144°C;
31P-NMR
(CD3COCD3, l) 144.49, 135.92 ppm; 1H-NMR
(CD3COCD3, l) 8.22–7.16 (m, 24H), 4.93 (m, 1H),
4.22 (m, 1H), 2.01–1.28 (m, 12H). Anal. Calc. for
C49H38O6P2: C, 74.99; H, 4.88. Found: C, 75.21; H,
4.97. Compound 9 was similarly prepared and a white
solid (57% yield) was obtained. [h]2D0= +435.1° (0.30,
toluene); m.p.=146–149°C; 31P-NMR (CD3COCD3,
l) 148.44, 137.64 ppm; 1H-NMR (CD3COCD3, l)
8.19–7.03 (m, 24H), 4.86 (m, 1H), 4.34 (m, 1H), 2.08–
1.28 (m, 12H). Anal. Calc. for C49H38O4P2: C, 74.99; H,
4.88. Found: C, 75.42; H, 5.05.
Table 2
4
2
3
,
Atomic coordinates (×10 ) and equivalent isotropic displacement parameters [A ×10 ] for Rh(7)(acac)
Atom
x
y
z
Ueq
Atom
x
y
z
Ueq
52(2)
Rh
P(1)
P(2)
6420(1)
17994(1)
17343(1)
19201(1)
16921(3)
18617(3)
19393(2)
17918(2)
16892(2)
16489(2)
15961(3)
12862(3)
19475(2)
20052(2)
20755(3)
23684(3)
19299(5)
18911(7)
17944(6)
17775(4)
18517(4)
18194(6)
18739(9)
19275(5)
18809(4)
15998(5)
16843(4)
17454(4)
18292(4)
1887(5)
6595(1)
7639(1)
6778(1)
6324(2)
5600(2)
7487(2)
8300(2)
8041(2)
7583(2)
32(1)
C(23)
C(24)
C(25)
C(26)
C(27)
C(28)
C(29)
C(30)
C(31)
C(32)
C(33)
C(34)
C(35)
C(36)
C(37)
C(38)
C(39)
C(40)
C(41)
C(42)
C(43)
C(44)
C(45)
C(46)
C(47)
C(48)
C(49)
C(50)
C(51)
C(52)
C(53)
C(54)
C(55)
C(56)
C(57)
C(58)
7742(5)
13743(4)
14032(4)
14945(4)
15578(4)
17813(4)
17376(6)
18642(4)
18131(6)
15221(5)
12148(4)
15231(4)
14413(5)
15626(5)
15899(6)
19813(4)
19357(4)
19726(4)
20501(4)
20984(4)
20653(4)
21263(4)
22182(4)
22796(4)
22503(4)
21584(4)
20977(3)
18483(4)
18585(7)
17680(5)
18295(6)
21315(6)
24345(4)
21296(4)
22114(5)
20720(5)
20751(5)
8112(3)
7462(3)
7275(3)
7763(3)
9125(3)
8575(5)
8743(4)
9803(4)
6621(1)
7049(1)
5747(3)
6193(3)
7528(3)
6831(3)
5631(3)
7552(3)
5321(4)
7720(4)
7996(3)
6149(3)
7470(4)
6445(4)
7896(6)
7193(9)
7316(8)
7715(5)
83370(5)
9517(6)
10094(7))
9405(5)
8445(5)
5000(6)
5452(5)
5485(5)
5833(5)
5784(6)
5553(4)
4727(5)
4698(5)
5434(5)
6207(5)
6253(4)
6990(4)
7092(5)
33(1)
33(1)
44(1)
45(1)
39(1)
39(1)
37(1)
43(1)
51(1)
74(2)
38(1)
36(1)
67(1)
59(1)
60(2)
115(4)
81(3)
50(2)
47(2)
75(2)
117(4)
62(2)
44(1)
71(2)
46(1)
51(2)
45(1)
68(2)
35(1)
40(1)
44(1)
40(1)
42(1)
36(1)
37(1)
46(2)
8334(5)
8271(5)
7577(4)
3853(5)
3324(6)
4266(6)
3030(6)
5980(6)
8260(6)
8921(5)
9621(7)
8203(6)
9605(6)
7903(4)
8487(5)
8325(5)
7612(5)
7108(5)
7268(4)
6795(4)
6853(5)
6318(5)
5708(5)
5633(4)
6231(4)
9281(5)
9990(8)
8726(7)
10034(7)
6547(7)
5866(6)
4878(5)
4183(7)
4137(5)
5457(6)
54(2)
45(1)
38(1)
48(2)
79(2)
67(2)
86(3)
72(2)
71(2)
52(2)
91(3)
68(2)
80(2)
37(1)
40(1)
50(2)
48(2)
43(1)
36(1))
36(1)
41(1)
44(1)
43(1)
37(1)
33(1)
51(2)
110(4)
103(4)
91(3)
73(2)
59(2)
44(1)
76(2)
60(2)
67(2)
O(1)
O(2)
O(3)
O(4)
O(5)
O(6)
O(7)
O(8)
O(9)
O(10)
O(11)
O(12)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
C(9)
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(17)
C(18)
C(19)
C(20)
C(21)
C(22)
11249(4)
7816(4)
6545(3)
6137(4)
6010(3)
6698(5)
5434(3)
4803(3)
4121(3)
4063(3)
4702(3)
5396(3)
6057(3)
5983(3)
6524(3)
7136(3)
7253(3)
6719(3)
4818(3)
5381(5)
4984(6)
4064(4)
3287(4)
6926(4)
7938(3)
8354(4)
7674(4)
8473(3)
11019(2)
8327(3)
6153(2)
6796(2)
3356(2)
6395(2)
8999(3)
9613(5)
9513(4)
8666(3)
8441(3)
8457(5)
7887(6)
7468(4)
7620(3)
5630(5)
5706(4)
5118(3)
5093(3)
4417(4)
8793(3)
9333(3)
10070(3)
10267(3)
9732(3)
8980(3)
8425(3)
8585(3)
16637(4)
17100(4)
16825(5)
16139(4)
15695(4)
15927(4)
15315(4)
14385(4)

164
Y. Jiang et al. / Journal of Organometallic Chemistry 586 (1999) 159–165
Table 3
3.4. Synthesis of Rh(7)(acac)
,
Selected bond distances (A) and bond angles (°) of Rh(7)(acac)
In a 20 ml Schlenk tube were dissolved compound 7
(36 mg, 0.0388 mmol) and Rh(CO)2(acac) (10 mg,
0.0387 mmol) in toluene (2.5 ml). The solution was
stirred at 40°C for 10 h and then stored at room
temperature. Pale yellow crystals were obtained from
the solution. 31P-NMR (CDCl3) l 135.8 (JRh–P=316
Bond distances
Rh–P(1)
Rh–P(2)
P(1)–O(4)
P(1)–O(5)
P(1)–O(6)
O(3)–C(9)
2.1586(14)
2.168(2)
1.589(4)
1.627(4)
1.617(4)
1.438(7)
Rh–O(1)
Rh–O(2)
P(2)–O(3)
P(2)–O(9)
P(2)–O(10)
O(4)–C(4)
2.074(4)
2.069(4)
1.598(4)
1.636(4)
1.593(4)
1.446(7)
1
Hz, JP–P=106 Hz), 142.5 (JRh–P=307 Hz). H-NMR
Bond angles
(CDCl3) l 6.98–6.63 (m, 8H), 5.17 (s, 1H), 4.83 (m,
1H), 4.55 (m, 1H), 3.83 (s, 3H), 3.81 (s, 6H), 3.78 (s,
3H), 2.08–1.05 (m, 54).
P(1)–Rh–P(2)
P(1)–Rh–O(1)
P(1)–Rh–O(2)
Rh–P(1)–O(4)
Rh–P(1)–O(5)
Rh–P(1)–O(6)
O(4)–P(1)–O(5)
O(4)–P(1)–O(6)
O(5)–P(1)–O(6)
P(1)–O(4)–C(4)
96.69(5)
89.56(11)
178.70(13)
119.8(2)
113.4(2)
115.4(2)
102.3(2)
101.6(2)
102.0(2)
128.2(4)
P(2)–Rh–O(1)
P(2)–Rh–O(2)
O(1)–Rh–O(2)
Rh–P(2)–O(3)
Rh–P(2)–O(9)
Rh–P(2)–O(10)
O(3)–P(2)–O(9)
O(3)–P(2)–O(10)
O(9)–P(2)–O(10)
P(2)–O(3)–C(9)
P(2)–O(9)–C(37)
173.48(11)
83.97(11)
89.7(2)
125.7(2)
118.7(2)
107.7(2)
95.9(2)
102.1(2)
103.8(2)
119.0(3)
125.2(3)
3.5. General procedure for the asymmetric
hydroformylation
The autoclave filled with Rh(acac)(CO)2 (0.0085
mmol) and diphosphite (0.025 mmol) was purged three
times with syn gas (CO/H2=1/1), then toluene (1.5 ml)
was added and pressurized to 10 atm of syn gas. The
reaction mixture was stirred for 10 h at 40°C to form
the active catalyst. Styrene or its derivatives (4.25
mmol) and toluene (1 ml) were placed in the autoclave
and the syn gas was introduced until the desired pres-
sure was reached. After the desired reaction time, the
autoclave was cooled to room temperature and depres-
suried. cis-Decahydronaphthalene as an internal stan-
dard was added. The mixture was filtered on silica gel
and the filtrate was analysed by GC for the yield and
regioselectivity. A sample of the filtration was oxidated
to acid by Jones oxidation and analysed by GC for
determination of the enantiomeric excess.
P(1)–O(5)–C(15) 119.1(3)
P(1)–O(6)–C(26) 132.7(4)
Rh–O(1)–C(11)
P(2)–O(10)–C(48) 128.5(3)
Rh–O(2)–C(13) 126.3(4)
124.4(4)
solid (48% yield) was obtained. [h]2D0= −41.3° (0.52,
toluene); m.p.=65–66°C; 31P-NMR (CD3COCD3, l)
145.86, 102.59 ppm; H-NMR (CD3COCD3, l) 7.58–
7.43 (m, 10H), 6.97–6.74 (m, 4H), 4.78 (m, 1H), 4.44
(m, 1H), 3.83 (s, 3H), 3.78 (s, 3H), 2.07–1.32 (m, 30H).
Anal. Calc. for C43H52O6P2: C, 71.06; H, 7.21. Found:
C, 71.51; H, 7.33.
1
Fig. 3. Molecular structure of Rh(7)(acac) emphasizing the distribution of tert-butyl groups.

Y. Jiang et al. / Journal of Organometallic Chemistry 586 (1999) 159–165
165
Table 4
[2] G. Consiglio, S.C.A. Mefkana, A. Borer, Organometallics 10
(1991) 2046.
Crystallographic data for Rh(7)(acac)
[3] I. Toth, I. Guo, B.E. Hanson, Organometallics 12 (1993) 848.
[4] L. Kollar, T. Kegi, J. Bakos, J. Organomet. Chem. 453 (1993)
155.
[5] P.W.N.M. van Leeuwen, C.F. Roobeek, J. Organomet. Chem.
258 (1983) 343.
[6] J.E. Babin, G.T. Whiteker, WO Pat. 911 (1992) 518.
[7] G.J.H. Buisman, E.J. Vos, P.C.J. Kamer, P.W.N.M. van
Leeuwen, J. Chem. Soc. Dalton Trans. (1995) 409.
[8] G.J.H. Buisman, M.E. Martin, E.J. Vos, K.A. Klootw, P.C.J.
Kamer, P.W.N.M. van Leeuwen, Tetrahedron: Asymmetry 6
(1995) 719.
[9] S. Cserepi-Szucs, I. Toth, L. Parkanyi, J. Bakos, Tetrahedron:
Asymmetry 9 (1998) 3135.
[10] R. Kadyrov, D. Heller, R. Selke, Tetrahedron: Asymmetry 9
(1998) 329.
[11] N. Sakai, S. Mano, K. Nozaki, H. Takaya, J. Am. Chem. Soc.
115 (1993) 7033.
[12] K. Nozaki, T. Nanno, H. Takaya, J. Organomet. Chem. 527
(1997) 103.
[13] K. Nozaki, N. Sakai, H. Takaya, J. Am. Chem. Soc. 119 (1997)
4413.
[14] Y.Z. Jiang, S. Xue, Z. Li, J.G. Deng, A.Q. Mi, A.S.C. Chan,
Tetrahedron: Asymmetry 9 (1998) 3185.
[15] A. Kless, J. Holz, D. Heller, Tetrahedron: Asymmetry 7 (1996)
33.
[16] Cserepi Szucs, J. Bakos, J. Chem. Soc. Chem. Commun. (1997)
635.
[17] A.S.C. Chan, W.H. Hu, Y.Z. Jiang, A.Q. Mi, J. Am. Chem. Soc.
119 (1997) 9570.
[18] A.S.C. Chan, C.C. Lin, J. Sun, W.H. Hu, Tetrahedron: Asym-
metry 6 (1995) 2953.
[19] C. Botteghi, S. Paganelli, A. Schionato, M. Marchetti, Chirality
3 (1991) 355.
Formula
C58H77O12P2Rh-
C4.75H5.75N0.25O0.25
1201.40
Pale yellow
P1
Triclinic
13.360(2)
14.926(3)
18.248(3)
88.56(1)
79.18(1)
80.44(1)
3524.5(11)
1.133
2
1270
0.340
0.50×0.36×0.16
293(2)
0.71073
1.57–25.00
ꢀ
Mn
Color
Space group
Crystal system
,
a (A)
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
3
,
V (A )
Dcalc. (g cm−3
)
Z
F(000)
v (mm−1
)
Crystal size (mm)
Temperature (K)
Wavelength (A)
q range (°)
,
Scan type
No. of data collected
No. of unique data
hkl range
13 967
12 392
0:15, −17:17, −21:21
0.0257
2
8516
748
0.974
0.0591
Rmerge
Observability criterion n, I\n|(I)
No. of data in refinement
No. of refined parameters
Goodness-of-fit on F2
Final R
wR
0.1775
[20] C.W. Lee, H. Alper, J. Org. Chem. 60 (1995) 499.
[21] A. van Rooy, P.C.J. Kamer, P.W.N.M. van Leeuwen, K. Goub-
itz, Organometallics 15 (1996) 835.
.
[22] J.G. Leipoldt, G.J. Lamprecht, G.J. van Zyl, Inorg. Chim. Acta
96 (1985) 31.
[23] A. van Rooy, E.J. vos, P.C.J. Kamer, P.W.N.M. van Leeuwen,
Organometallics 15 (1996) 835.
[24] A. Meetsma, T. Jongsma, G. Challa, P.W.N.M. van Leeuwen,
Acta Crystallorgr. C49 (1993) 1160.
Acknowledgements
We are grateful for the financial support of the
Natural Science Foundation of China (29790124).
[25] M.L. Caffrey, T.L. Brown, Inorg. Chem. 30 (1991) 3907.
[26] H. Brunner, A. Winter, J. Bred, J. Organomet. Chem. 553 (1998)
285.
References
[27] K. Kushioka, J. Org. Chem. 49 (1984) 4456.
[28] T. Jongsma, M. Fossen, G. Challa, P.W.N.M. van Leeuwen, J.
Mol. Catal. 83 (1993) 17.
[1] G. Consiglio, in: I. Ojima (Ed.), Catalytic Asymmetric Synthesis,
New York, 1993, p. 273.
.