Synthesis of dinuclear complexes bearing metalloporphyrin-phosphine hybrid ligands and their catalytic activity toward hydrosilylation of ketones

Article abstract of DOI:10.1021/om0498201

A new type of metalloporphyrin - phosphine hybrid ligand (1) has been designed and synthesized. Reactions of some transition metal complexes such as PdCl₂, PtCl₂, and [RhCl-(CO)₂]₂ with a zinc porphyrin-phosphine ligand (1; M¹ = Zn) afford the corresponding dinuclear complexes (2) bearing the hybrid ligand. The zinc porphyrin-phosphine compound (1; M¹ = Zn, R = Ph) has been found to work as an effective ligand for Rh(D-or Ir(I)-catalyzed hydrosilylation of ketones to give the corresponding alcohols after acid hydrolysis.

Full text of DOI:10.1021/om0498201

4012
Organometallics 2004, 23, 4012-4017
Articles
Syn th esis of Din u clea r Com p lexes Bea r in g
Meta llop or p h yr in -P h osp h in e Hybr id Liga n d s a n d Th eir
Ca ta lytic Activity tow a r d Hyd r osilyla tion of Keton es
Makoto Saito, Yoshiaki Nishibayashi,* and Sakae Uemura*
Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering,
Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, J apan
Received March 12, 2004
A new type of metalloporphyrin-phosphine hybrid ligand (1) has been designed and
synthesized. Reactions of some transition metal complexes such as PdCl2, PtCl2, and [RhCl-
(CO)2]2 with a zinc porphyrin-phosphine ligand (1; M1 ) Zn) afford the corresponding
dinuclear complexes (2) bearing the hybrid ligand. The zinc porphyrin-phosphine compound
(1; M1 ) Zn, R ) Ph) has been found to work as an effective ligand for Rh(I)- or Ir(I)-catalyzed
hydrosilylation of ketones to give the corresponding alcohols after acid hydrolysis.
Sch em e 1
In tr od u ction
Up until now, many types of mononuclear and poly-
nuclear dinitrogen (N2) complexes of various transition
metals have been prepared, and some of them have
been known to liberate ammonia (NH3) or hydrazine
(NH2NH2) by protonolysis with inorganic acids such as
H2SO4 and HCl.1,2 Recently, one of the authors has
reported the formation of NH3 by ruthenium-assisted
protonation of coordinated N2 on the W atom with H2
under mild reaction conditions.3 As an extension of this
multimetallic approach for nitrogen fixation, we have
envisaged to design a new type of metalloporphyrin-
phosphine hybrid ligand (1)4 and the corresponding
dinuclear N2 complexes (3) bearing this hybrid ligand,
as shown in Scheme 1, although some N2 complexes of
porphyrin have already been prepared, where N2 is
coordinated on the central metal of porphyrin.5,6 It is
expected that the metalloporphyrin moiety in 3 induces
intramolecular electron and energy transfer of the exci-
tation energy into the metal center, where the conver-
sion of solar energy into chemical potentials in the form
of a charge-separated state takes place, because the
metalloporphyrin moiety has a light-harvesting antenna
system.7,8 As a result, the properties of the light-driven
energy migration and transfer of 1 are considered to
change the coordination mode of N2 on the metal in 3.9
Unfortunately, we have not yet succeeded in preparing
N2 complexes 3 with a metalloporphyrin-phosphine
hybrid ligand, but we could prepare some transition
* Corresponding authors. E-mail: ynishiba@scl.kyoto-u.ac.jp (Y.N.);
uemura@scl.kyoto-u.ac.jp (SU).
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V.; Schrock, R. R. Science 2003, 301, 76. (k) Evans, W. J .; Lee, W. S.;
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E.; Chirik, P. J . Nature 2004, 427, 527. (m) Ritleng, V.; Yandulov, D.
V.; Weare, W. W.; Schrock, R. R.; Hock, A. S.; Davis, W. M. J . Am.
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(4) Independently, Sawamura and co-workers have partly reported
the preparation of 1 by a different method at the 74th Annual Meeting
of the Chemical Society of J apan, Kyoto, March 1998, Abstract 4A315.
10.1021/om0498201 CCC: $27.50 © 2004 American Chemical Society
Publication on Web 07/17/2004

Metalloporphyrin-Phosphine Hybrid Ligands
Organometallics, Vol. 23, No. 17, 2004 4013
Sch em e 2
metal complexes (2) bearing this hybrid ligand. Here,
we describe the method for the preparation of some
transition metal complexes (2) bearing the hybrid ligand
and their catalytic activity toward rhodium(I)- and
iridium(I)-catalyzed hydrosilylation of some ketones.
P r ep a r a t ion of Din u clea r Com p lexes Bea r in g
syn -1. The coordinated properties of syn-1 were first
examined with a platinum complex because the isomeric
structures (trans or cis) are easily determined by the
in 31P{1H} NMR.14,15 Treatment
195Pt-31
P
magnitude of J
of platinum(II) complex [PtCl2(PhCN)2] with syn-1 at
room temperature for 5 h in CH2Cl2 gave the corre-
sponding dinuclear complex (2a ) in 30% isolated yield
(Scheme 3) with complete selectivity. The 31P{1H} NMR
spectrum of 2a (17.6 ppm in CDCl3) was accompanied
Resu lts a n d Discu ssion
P r ep a r a tion of th e Zin c P or p h yr in -P h osp h in e
Hybr id Ligan d (syn -1). The porphyrin-phosphinothioyl
hybrid ligand (4) was prepared by treatment of 3′-
(diphenylphosphinothioyl)biphenyl-2-carbaldehyde (5),
which was obtained easily from the reaction of 3-(diphen-
ylphosphinothioyl)bromobenzene (6) with 2-formylphen-
ylboronic acid in the presence of a catalytic amount of
Pd(OAc)2 and 2-(di-tert-butylphosphino)biphenyl at room
temperature for 20 h (70% isolated yield based on 6),10
with dipyrromethane in the presence of trifluoroacetic
acid (TFA), followed by oxidation with p-chloranil
(Scheme 2).11 Although a mixture of two isomers of 4
was formed with the isomer ratio 1:1, only the syn
isomer (syn-4) was isolated in 21% isolated yield based
on 4 by flash chromatography. Treatment of syn-4 with
Zn(OAc)2 at reflux temperature for 5 h in MeOH/CHCl3
gave the corresponding zinc porphyrin-phosphinothioyl
hybrid ligand (syn-7) in 98% isolated yield.12 The
structure of syn-7 is unambiguously clarified by X-ray
crystallography, an ORTEP drawing of syn-7 being
shown in Figure 1. Selected bond lengths and angles of
syn-7 are listed in Tables 1 and 2, respectively. Finally,
treatment of syn-7 with an excess amount of [Cp2ZrHCl]
gave the reduced phosphine, syn-1, in 81% isolated yield
based on syn-7.13 Thus, syn-1 was prepared in 10%
overall isolated yield based on 6.
by its 195Pt satellite with a J
value of 2598 Hz,
195Pt-31P
indicating the trans geometry of two phosphorus atoms
in 2a . Similar treatment of palladium(II) complex
[PdCl2(MeCN)2] with syn-1 at room temperature for 7
h in benzene afforded the corresponding dinuclear
complex 2b in 49% isolated yield with complete selectiv-
ity. Furthermore, the reaction of [RhCl(CO)2]2 with
syn-1 in a 1:2 molar ratio at room temperature for 1 h
in tetrahydrofuran (THF) afforded the dinuclear com-
plex 2c in 20% isolated yield. The IR spectrum of 2c
exhibited an absorption at 1973 cm-1 (νCdO). Unfortu-
nately, when an equimolar mixture of tungsten N2
complex trans-[W(N2)2(PMePh2)4]16 and syn-1 was stirred
at room temperature for 1 h in THF, no formation of
(10) Wolfe, J . P.; Singer, R. A.; Yang, B. H.; Buchwald, S. L. J . Am.
Chem. Soc. 1999, 121, 9550, and references therein.
(11) Kadish, K. M., Smith, K. M., Guilard, R., Eds. The Porphyrin
Handbook; Academic Press: San Diego, 2000; Vol. 1.
(12) For an example see: Imahori, H.; Tamaki, K.; Araki, Y.;
Sekiguchi, Y.; Ito, O.; Sakata, Y.; Fukuzumi, S. J . Am. Chem. Soc. 2002,
124, 5165.
(13) Zablocka, M.; Delest, B.; Igau, A.; Skowronska, A.; Majoral, J .-
P. Tetrahedron Lett. 1997, 38, 5997.
F igu r e 1. Molecular structure of syn-7.

4014 Organometallics, Vol. 23, No. 17, 2004
Saito et al.
Ta ble 1. Selected Bon d Len gth s (Å) for syn -7
Sch em e 3
Zn(1)-N(1)
Zn(1)-N(2)
Zn(1)-N(3)
Zn(1)-N(4)
P(1)-S(1)
2.041(8)
2.025(8)
2.056(8)
2.042(8)
1.956(4)
1.946(5)
1.80(1)
1.80(1)
1.80(1)
1.80(1)
1.80(1)
1.80(1)
1.39(1)
1.35(1)
1.37(1)
1.38(1)
1.37(1)
1.37(1)
1.37(1)
1.36(1)
1.38(1)
1.51(1)
1.41(1)
1.48(1)
1.40(1)
C(1)-C(2)
1.43(1)
1.36(1)
1.45(1)
1.39(1)
1.39(1)
1.46(1)
1.34(1)
1.43(1)
1.41(1)
1.37(1)
1.43(1)
1.35(1)
1.45(1)
1.39(1)
1.42(1)
1.45(1)
1.34(1)
1.43(1)
1.40(1)
1.39(1)
1.51(1)
1.38(1)
1.51(1)
1.36(1)
1.42(2)
C(2)-C(3)
C(3)-C(4)
C(4)-C(5)
C(5)-C(6)
P(2)-S(2)
C(6)-C(7)
P(1)-C(29)
P(1)-C(33)
P(1)-C(39)
P(2)-C(53)
P(2)-C(57)
P(2)-C(63)
N(1)-C(11)
N(1)-C(14)
N(2)-C(6)
N(2)-C(9)
N(3)-C(1)
N(3)-C(4)
N(4)-C(16)
N(4)-C(19)
C(1)-C(20)
C(5)-C(22)
C(21)-C(22)
C(21)-C(27)
C(27)-C(28)
C(7)-C(8)
C(8)-C(9)
C(9)-C(10)
C(10)-C(11)
C(11)-C(12)
C(12)-C(13)
C(13)-C(14)
C(14)-C(15)
C(15)-C(16)
C(16)-C(17)
C(17)-C(18)
C(18)-C(19)
C(19)-C(20)
C(28)-C(29)
C(15)-C(45)
C(45)-C(46)
C(46)-C(51)
C(51)-C(52)
C(52)-C(53)
Ta ble 2. Selected An gles (d eg) for syn -7
N(1)-Zn(1)-N(2) 114.0(3)
90.9(3) S(1)-P(1)-C(29)
88.4(3) S(1)-P(1)-C(33)
172.8(3) S(1)-P(1)-C(39)
88.5(3) C(29)-P(1)-C(33)
171.0(3) C(29)-P(1)-C(39)
91.1(3) C(33)-P(1)-C(39)
125.7(6) S(2)-P(2)-C(53)
127.8(7) S(2)-P(2)-C(57)
127.0(7) S(2)-P(2)-C(63)
126.4(6) C(53)-P(2)-C(57)
124.8(6) C(53)-P(2)-C(63)
126.0(6) C(57)-P(2)-C(63)
127.5(7) C(1)-C(2)-C(3)
125.5(6) C(1)-C(20)-C(19)
107.1(8) C(2)-C(1)-C(20)
106.5(8) C(2)-C(3)-C(4)
106.5(8) C(3)-C(4)-C(5)
107.0(8) C(4)-C(5)-C(6)
125.2(9) C(5)-C(6)-C(7)
108.8(9) C(6)-C(7)-C(8)
110.1(9) C(7)-C(8)-C(9)
125.8(9) C(8)-C(9)-C(10)
125.9(9) C(9)-C(10)-C(11)
N(2)-Zn(1)-N(3)
N(1)-Zn(1)-N(3)
N(1)-Zn(1)-N(4)
N(2)-Zn(1)-N(4)
N(3)-Zn(1)-N(4)
Zn(1)-N(1)-C(11)
Zn(1)-N(1)-C(14)
Zn(1)-N(2)-C(6)
Zn(1)-N(2)-C(9)
Zn(1)-N(3)-C(1)
Zn(1)-N(3)-C(4)
Zn(1)-N(4)-C(16)
Zn(1)-N(4)-C(19)
C(1)-N(3)-C(4)
C(6)-N(2)-C(9)
C(11)-N(1)-C(14)
C(16)-N(4)-C(19)
N(1)-C(11)-C(10)
N(1)-C(11)-C(12)
N(1)-C(14)-C(13)
N(1)-C(14)-C(15)
N(2)-C(6)-C(5)
N(2)-C(6)-C(7)
N(2)-C(9)-C(8)
N(2)-C(9)-C(10)
N(3)-C(1)-C(2)
N(3)-C(1)-C(20)
N(3)-C(4)-C(3)
N(3)-C(4)-C(5)
N(4)-C(16)-C(15)
N(4)-C(16)-C(17)
N(4)-C(19)-C(18)
N(4)-C(19)-C(20)
P(1)-C(29)-C(28)
112.5(4)
111.7(4)
107.1(5)
106.3(5)
104.7(5)
113.6(4)
113.8(5)
113.0(5)
104.1(6)
106.4(6)
105.1(7)
107.0(9)
128.1(9)
125.5(9)
107.0(9)
125.7(9)
124.4(9)
125.8(9)
108.3(9)
106.6(8)
125.2(9)
127.3(9)
ruthenium-catalyzed hydrosilylation of ketones in de-
tail.17 The formation of the corresponding dinuclear
complex was confirmed by 31P{1H} NMR in the reaction
of [RhCl(COD)]2 or [IrCl(COD)]2 with syn-1 in CDCl3
at room temperature for 30 min. In the case of the Rh
complex, one doublet peak was observed at 27.6 (J Rh-P
) 146 Hz) ppm, and in the case of the Ir complex, one
singlet peak was observed at 18.7 ppm. Thus, only one
isomer was quantitatively formed in both cases. This
fact indicates that the complexes formed in situ are
suitable to investigate their catalytic activity toward
hydrosilylation without further purification. Treatment
of acetophenone (0.20 mmol) with diphenylsilane (0.60
mmol) in the presence of a catalytic amount of [RhCl-
(COD)]2 or [IrCl(COD)]2 (0.001 mmol; 0.5 mol %) and
ligand syn-1 (0.002 mmol; 1 mol %) at room temperature
for 24 h in anhydrous THF afforded 1-phenylethanol in
53% or 26% GLC yield after acid hydrolysis, respectively
(Table 3; runs 1 and 2; Scheme 4). Similarly, rhodium-
108.2(9) C(10)-C(11)-C(12) 126.0(9)
110.3(8) C(11)-C(12)-C(13) 108.2(9)
124.3(9) C(12)-C(13)-C(14) 106.2(9)
109.9(9) C(13)-C(14)-C(15) 123.9(9)
124.5(9) C(14)-C(15)-C(16) 124.3(9)
108.9(9) C(15)-C(16)-C(17) 125.0(9)
125.4(9) C(16)-C(17)-C(18) 105.5(9)
125.2(9) C(17)-C(18)-C(19) 109.0(1)
109.7(9) C(18)-C(19)-C(20) 126.3(9)
108.8(9) C(4)-C(5)-C(22)
124.9(9) C(6)-C(5)-C(22)
119.6(7) C(5)-C(22)-C(21)
118.7(9)
116.6(9)
119.6(8)
(14) Rahn, J . A.; Baltusis, L.; Nelson, J . H. Inorg. Chem. 1990, 29,
750.
(15) Sawamura, M.; Hamashima, H.; Ito, Y. Tetrahedron: Asym-
metry 1991, 2, 593.
(16) (a) Chatt, J .; Pearman, A. J .; Richards, R. L. Nature (London)
1975, 253, 39. (b) Chatt, J .; Pearman, A. J .; Richards, R. L. J . Chem.
Soc., Dalton Trans. 1977, 1852. (c) Chatt, J .; Pearman, A. J .; Richards,
R. L. J . Chem. Soc., Dalton Trans. 1977, 2139.
C(14)-C(15)-C(45) 119.4(9) C(22)-C(21)-C(27) 123.1(9)
C(16)-C(15)-C(45) 116.3(9) C(21)-C(27)-C(28) 122.4(9)
C(15)-C(45)-C(46) 123.0(9) C(27)-C(28)-C(29) 122.6(9)
C(45)-C(46)-C(51) 122.1(9) C(51)-C(52)-C(53) 121.4(1)
C(46)-C(51)-C(52) 120.6(1) P(2)-C(53)-C(52)
119.3(9)
(17) (a) Nishibayashi, Y.; Segawa, K.; Ohe, K.; Uemura, S. Orga-
nometallics 1995, 14, 5486. (b) Nishibayashi, Y.; Segawa, K.; Takada,
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the corresponding novel N2 complex was observed even
by 31P{1H} NMR.
Ca ta lytic Rea ctivity tow a r d Hyd r osilyla tion of
Keton es. To obtain some information on the catalytic
activity of the dinuclear complexes 2 where syn-1 works
as a ligand, we examined the rhodium- and iridium-
catalyzed hydrosilylation of some ketones because we
have previously investigated the rhodium-, iridium-, and

Metalloporphyrin-Phosphine Hybrid Ligands
Organometallics, Vol. 23, No. 17, 2004 4015
Ta ble 3. Rh od iu m - or Ir id iu m -Ca ta lyzed
Hyd r osilyla tion of Acetop h en on esa
Exp er im en ta l Section
1
Gen er a l Meth od s. H NMR (400, 300, and 270 MHz) and
reaction
yield
(%)b
31P{1H} NMR (161.7 MHz) spectra were recorded using CDCl3
or C6D6 as solvent. GLC analyses were performed on a
Shimadzu GC-14B instrument equipped with a flame ioniza-
tion detector using a 25 m × 0.25 mm CBP 10 fused silica
capillary column. Elemental analyses were performed at
Microanalytical Center of Kyoto University. High-resolution
mass spectra and low-resolution mass spectra were measured
on a J EOL J MS600H mass spectrometer. UV-visible spectra
were recorded on a Shimadzu Multispec-1500 spectrometer.
IR spectra were recorded on an FT-IR spectrometer. All
reactions were carried out under a dry nitrogen atmosphere.
Solvents were dried by the usual methods and distilled be-
fore use. Unless otherwise noted, all manipulations were
done by use of Schlenk techniques. 2-Formylphenylboronic
acid, 2-(di-tert-butylphosphino)biphenyl, Zn(OAc)2, [Cp2ZrHCl],
Pd(OAc)2, [RhCl(CO)2]2, [RhCl(COD)]2, [IrCl(COD)]2, acetophe-
none, diphenylsilane, dppf, dppe, and dppp were commercial
products. 3-(Diphenylphosphinyl)bromobenzene,18 dipyrrometh-
run
X
catalyst
ligand
time (h)
1
2
3
4
5
6
7
8
H
H
Cl
OMe
H
H
H
H
H
H
H
[RhCl(COD)]2
[IrCl(COD)]2
[RhCl(COD)]2
[RhCl(COD)]2
[RhCl(COD)]2
[RhCl(COD)]2
[RhCl(COD)]2
[RhCl(COD)]2
[IrCl(COD)]2
[RhCl(COD)]2
[RhCl(COD)]2
[RhCl(COD)]2
syn-1
syn-1
syn-1
syn-1
dppf
dppe
dppp
24
24
24
24
24
24
24
24
24
8
53
26
82
18
73
36
54
0
9
0
10
11c
12d
syn-1
syn-1
syn-1
41
38
44
8
8
H
a
All the reactions of acetophenones (0.20 mmol) with diphe-
nylsilane (0.60 mmol) were carried out in the presence of
[M(COD)Cl]2 (M ) Rh or Ir) (0.001 mmol) and ligand (0.002 mmol)
b
in THF (5 mL) at room temperature. GLC yield. c In the dark.
d
The reaction mixture was irradiated with a high-pressure Hg
lamp without a slit.
ane,19 PtCl2(PhCN)2,20 and PdCl2(MeCN)2 were prepared
21
Sch em e 4
according to reported procedures.
3-(Dip h en ylp h osp h in oth ioyl)br om oben zen e (6). In a
200 mL flask, 3-(diphenylphosphinyl)bromobenzene (9.72 g,
28.5 mmol) and elemental sulfur (1.02 g, 31.9 mmol) were
stirred in THF (80 mL) at room temperature under N2. The
reaction mixture was stirred overnight, and then the reaction
mixture was concentrated in vacuo. The crude mixture was
purified by flash chromatography on silica gel to give a white
solid (6) (8.90 g, 23.8 mmol; 84%): 1H NMR (CDCl3) δ 7.29
(dt, 1H, J ) 3.2 and 7.8 Hz), 7.40-7.53 (m, 6H), 7.54-7.64
(m, 2H), 7.66-7.76 (m, 4H), 7.88 (dt, 1H, J ) 1.4 and 13.2
Hz); 31P{1H} NMR (CDCl3) δ 40.0; HRMS (FAB) calcd for
catalyzed hydrosilylation of substituted acetophenones
such as p-chloroacetophenone and p-methoxyacetophe-
none with diphenylsilane proceeded to give the corre-
sponding alcohols in 82% and 18% GLC yields, respec-
tively (Table 3; runs 3 and 4). For comparison, typical
bidentate diphosphines such as dppf (1,1′-bis(diphe-
nylphosphino)ferrocene), dppe (1,2-bis(diphenylphos-
phino)ethane), and dppp (1,3-bis(diphenylphosphino)-
propane) were used as ligands for the rhodium-catalyzed
hydrosilylation of acetophenone under the same reaction
conditions (Table 3; runs 5-7). No reaction proceeded
in the absence of phosphine ligands in both cases (Table
3; runs 8 and 9). These results indicate that syn-1 works
as a suitable diphosphine ligand for rhodium- and
iridium-catalyzed hydrosilylation of ketones. To inves-
tigate the effect of light, the catalytic hydrosilylation of
acetophenone by using syn-1 as ligand was carried out
in the dark (Table 3; runs 10-12), where the catalytic
reaction proceeded smoothly. On the other hand, when
the reaction mixture was irradiated with a high-pres-
sure Hg lamp (450 W) without a slit, the catalytic
reaction was not accelerated at all. Further work is
currently in progress aimed at finding new catalytic
activity.
C
C
18H1479BrPS (M + H+) 372.9815, found 372.9808; calcd for
18H1481BrPS (M + H+) 374.9796, found 374.9796. Anal. Calcd
for C18H14BrPS: C, 57.92; H, 3.78. Found: C, 58.73; H, 3.85.
3′-(Dip h e n ylp h osp h in ot h ioyl)b ip h e n yl-2-ca r b a ld e -
h yd e (5). In a 100 mL flask, 3-(diphenylphosphinothioyl)-
bromobenzene (6) (8.90 g, 23.8 mmol), Pd(OAc)2 (117 mg, 0.523
mmol), 2-(di-tert-butylphosphino)biphenyl (301 mg, 1.01 mmol),
KF (4.07 g, 70.0 mmol), and 2-formylphenylboronic acid (3.81
g, 25.4 mmol) were stirred in THF (50 mL) at room temper-
ature for 20 h under N2. The reaction mixture was then diluted
with diethyl ether (100 mL) and poured into a separatory
funnel. The reaction mixture was washed with aqueous 1 N
NaOH (50 mL × 3), and the aqueous layers were extracted
with diethyl ether (50 mL × 3). The combined organic layers
were washed with brine, dried over anhydrous MgSO4, and
concentrated in vacuo. The crude mixture was purified by
flash chromatography on silica gel to give a white solid (5)
(6.61 g, 16.6 mmol; 70%): 1H NMR (CDCl3) δ 7.38-7.65 (m,
11H), 7.73-7.80 (m, 6H), 7.99 (dd, 1H, J ) 1.0 and 7.8 Hz),
9.90 (s, 1H); 31P{1H} NMR (CDCl3) δ 40.4 (s). Anal. Calcd for
C
25H19OPS: C, 75.36; H, 4.81. Found: C, 75.31; H, 5.00.
syn -5,15-Bis[3′-(d ip h en ylp h osp h in oth ioyl)bip h en yl-2-
yl]p or p h yr in (syn -4). In a 1 L flask, 3′-(diphenylphosphi-
nothioyl)biphenyl-2-carbaldehyde (5) (2.04 g, 5.12 mmol) and
dipyrromethane (0.752 g, 5.15 mmol) were dissolved in
CH2Cl2 (500 mL) under N2, and then TFA (0.55 mL, 7.13
mmol) was added slowly. The reaction mixture was stirred at
room temperature for 3 h, and then p-chloranil (1.29 g, 4.07
mmol) was added to it. After the reaction mixture was further
stirred at room temperature for another 20 h, it was concen-
Con clu sion
In summary, we have developed a new route to the
porphyrin-phosphine hybrid ligand (syn-1) and pre-
pared the novel rhodium-, palladium-, and platinum-
zinc dinuclear complexes bearing syn-1. The molecular
structure of porphyrin-phosphinothioyl hybrid ligand
syn-7 is unambiguously clarified by X-ray crystallog-
raphy. The compound syn-1 has been revealed to work
as a ligand for Rh- and Ir-catalyzed hydrosilylation of
ketones.
(18) Brauer, D. J .; Hingst, M.; Kottsieper, K. W.; Liek, C.; Nickel,
T.; Tepper, M.; Stelzer, O.; Sheldrick, W. S. J . Organomet. Chem. 2002,
645, 14.
(19) Wang, Q. M.; Bruce, D, W. Synlett 1995, 1267.
(20) Braunstein, P.; Bender, R.; J ud, J . Inorg. Synth. 1987, 26, 345.
(21) Doyle, J . R.; Slade, P. E.; J onassen, H. B. Inorg. Synth. 1960,
6, 218.

4016 Organometallics, Vol. 23, No. 17, 2004
Saito et al.
Ta ble 4. Cr ysta llogr a p h ic Da ta for syn -7
trated in vacuo. The crude mixture was purified by flash
chromatography on silica gel to give a purple solid (syn-4) (607
mg, 0.547 mmol; 21%), which was recrystallized from CH2Cl2/
n-hexane: 1H NMR (CDCl3) δ 6.27 (dt, 8H, J ) 3.2 and 7.6
Hz), 6.42-6.47 (m, 6H), 6.57 (dd, 8H, J ) 7.6 and 13.4 Hz),
6.81 (dd, 2H, J ) 7.6 and 13.4 Hz), 7.29 (d, 2H, J ) 6.8 Hz),
7.70-7.86 (m, 10H), 8.04 (d, 2H, J ) 6.8 Hz) 8.91 (d, 4H, J )
formula
fw
cryst size (mm)
cryst syst
space group
cryst color
a (Å)
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
C
70H50N4Cl4P2S2Zn
1280.45
0.60 x 0.40 x 0.10
triclinic
P1h (#2)
black
11.9579(3)
12.3233(3)
22.1029(5)
106.002(2)
97.916(2)
92.123(1)
3091.4(1)
2
4.8 Hz), 9.21 (d, 4H,
J
) 4.8 Hz), 10.09 (s, 2H);
31P{1H} NMR (CDCl3) δ 40.1 (s); UV/vis (CHCl3) λmax (log ꢀ)
369 (3.24), 414 (5.41), 440 (4.21), 507 (4.10), 540 (3.65), 580
(3.66), 635 (3.36) nm. Anal. Calcd for C68H48N4P2S2‚CH2Cl2
(syn-4‚CH2Cl2): C, 73.20; H, 4.45; N, 4.95. Found: C, 72.88;
H, 4.60; N, 4.73.
Z
d
Representative data of anti-4 are as follows:22 1H NMR
(CDCl3) δ 9.97 (s, 2H); 31P{1H} NMR (CDCl3) δ 40.4 (s).
syn -{5,15-Bis[3′-(d ip h en ylp h osp h in oth ioyl)bip h en yl-2-
yl]p or p h yr in a to}zin c(II) (syn -7). In a 50 mL flask, syn-5,-
15-bis[3′-(diphenylphosphinothioyl)biphenyl-2-yl]porphyrin (syn-
4) (33.9 mg, 0.0324 mmol) dissolved in CHCl3 (20 mL) was
added to a saturated methanol solution with zinc acetate (5
mL), and the solution was stirred at reflux temperature for 5
h under N2. The reaction mixture was poured into water, and
the resulting mixture was extracted with CHCl3 (20 mL × 3).
The organic layer was washed with water (40 mL × 2), dried
over anhydrous MgSO4, and concentrated in vacuo to give a
purple solid (syn-7) (35.3 mg, 0.0318 mmol; 98%), which was
recrystallized from CH2Cl2/n-hexane: 1H NMR (CDCl3) δ 6.15
(t, 2H, J ) 7.6 Hz), 6.36 (dd, 2H, J ) 7.6 and 13.2 Hz), 6.43
(dd, 8H, J ) 7.6 and 13.2 Hz), 6.63 (dt, 8H, J ) 2.0 and 7.6
Hz), 6.74 (dt, 4H, J ) 2.0 and 7.6 Hz), 6.98 (d, 2H, J ) 13.2
Hz), 7.17 (d, 2H, J ) 7.6 Hz), 7.74 (t, 4H, J ) 7.6 Hz), 7.84 (t,
calc (g cm-1
)
1.375
F(000)
1316.00
7.35
µ
calc (cm-1
)
no. of unique data
no. of data used (I > 3σ(I))
no. of params refined
Ra
11527
5136
798
0.075
b
Rw
0.084
goodness of fit indicator
1.55
0.66
max. residuals (e A-3
)
a
b
2
1/2
R ) ∑|Fo| - |Fc||/∑|Fo|. Rw ) [∑w(|Fo| - |Fc|)2/∑wFo
] .
2H,
J
)
7.6 Hz), 8.29 (d, 2H,
J
) 7.6 Hz), 8.94
(d, 4H, J ) 4.4 Hz), 9.21 (d, 4H, J ) 4.4 Hz), 10.06 (s, 2H);
31P{1H} NMR (CDCl3) δ 39.1 (s); UV/vis (CHCl3) λmax (log ꢀ)
313 (4.56), 420 (5.51), 547 (4.43), 622 (4.07) nm. Anal. Calcd
for C68H46N4P2S2Zn‚2CH2Cl2 (syn-7‚2CH2Cl2): C, 65.66; H,
3.94; N, 4.38. Found: C, 65.63; H, 4.07; N, 4.30.
syn -{5,15-Bis(3′-d ip h e n ylp h osp h in ylb ip h e n yl-2-yl)-
p or p h yr in a to}zin c(II) (syn -1). In a 20 mL flask, syn-{5,15-
bis[3′-(diphenylphosphinothioyl)biphenyl-2-yl]porphyrinato}-
zinc(II) (syn-7) (43.8 mg, 0.0394 mmol) and [Cp2ZrHCl] (63.2
mg, 0.245 mmol) were stirred in THF (5 mL) at 60 °C for 3 h
under N2. The reaction mixture was concentrated in vacuo and
purified by flash chromatography on silica gel under N2 to give
a purple solid (syn-1) (33.5 mg, 0.0320 mmol; 81%): 1H NMR
(C6D6) δ 6.08 (t, 2H, J ) 7.8 Hz), 6.22-6.38 (m, 14H), 6.54 (t,
8H, J ) 7.8 Hz), 7.29 (d, 2H, J ) 7.8 Hz), 7.38 (t, 2H, J ) 7.8
Hz), 7.56 (t, 2H, J ) 7.8 Hz), 7.70 (d, 2H, J ) 7.8 Hz), 7.78 (d,
2H, J ) 7.8 Hz), 7.90 (d, 2H, J ) 7.8 Hz), 9.01 (d, 4H, J ) 4.4
Hz), 9.09 (d, 4H, J ) 4.4 Hz), 9.89 (s, 2H); 31P{1H} NMR (C6D6)
δ -8.8 (s); LRMS (FAB) calcd for C68H46N4ZnP2 (syn-1) 1046,
found 1046; UV/vis (CHCl3) λmax (log ꢀ) 418 (5.50), 458 (4.46),
498 (4.42), 544 (4.44), 620 (4.26) nm.
F igu r e 2. Molecular structure of anti-4′.
dichloromethane (6 mL) at room temperature for 5 h. The
solvent was then removed under vacuum. The residue was
recrystallized from CHCl3/n-hexane to give a purple solid (2a )
(20.1 mg, 0.0153 mmol; 30%): 1H NMR (CDCl3) δ 6.18 (br,
2H), 6.25-6.46 (br, 10H), 7.51-7.78 (m, 22H), 7.92 (d, 2H, J
) 8.0 Hz), 8.45 (br, 4H), 8.15 (br, 4H), 9.97 (s, 2H); 31P{1H}
NMR (CDCl3) δ 17.7 (s with 195Pt satellites, J Pt-P ) 2598 Hz).
Anal. Calcd for C68H46N4Cl2P2PtZn‚2CHCl3 (2a ‚2CHCl3): C,
54.20; H, 3.12; N, 3.61. Found: C, 54.44; H, 3.41; N, 3.84.
2b. In a 20 mL flask, syn-{5,15-bis(3′-diphenylphosphanyl-
biphenyl-2-yl)porphinato}zinc(II) (syn-1) (42.1 mg, 0.0402
mmol) and PdCl2(MeCN)2 (10.0 mg, 0.0385 mmol) were stirred
in benzene (8 mL) at room temperature for 8 h. The solvent
was then removed under vacuum. The residue was recrystal-
lized from CH2Cl2/n-hexane to give a purple solid (2b) (23.0
mg, 0.0188 mmol; 49%): 1H NMR (CDCl3) δ 5.93 (br, 2H), 6.17
(br, 8H), 6.32-6.46 (m, 2H), 6.91 (br, 10H), 7.16 (t, 2H, J )
7.0 Hz), 7.68-7.91 (m, 10H), 8.43 (d, 2H, J ) 7.2 Hz), 8.66 (d,
4H, J ) 3.6 Hz), 8.90 (br, 4H), 9.82 (s, 2H); 31P{1H} NMR
(CDCl3) δ 21.0 (s). Anal. Calcd for C68H46N4Cl2P2PdZn‚2CH2-
Cl2 (2b‚2CH2Cl2): C, 60.33; H, 3.62; N, 4.02. Found: C, 60.23;
H, 3.85; N, 3.65.
P r ep a r a tion of Din u clea r Com p lexes Bea r in g syn -1.
2a . In a 20 mL flask, syn-{5,15-bis(3′-diphenylphosphanylbi-
phenyl-2-yl)porphinato}zinc(II) (syn-1) (56.4 mg, 0.0539 mmol)
and PtCl2(PhCN)2 (23.7 mg, 0.0502 mmol) were stirred in
(22) Separately, we have confirmed the molecular structure of anti-
4′ (see below and Figure 2) by X-ray crystallography. Saito M.;
Nishibayashi, Y.; Uemura, S. Unpublished results.
2c. In a 20 mL flask, syn-{5,15-bis(3′-diphenylphosphanyl-
biphenyl-2-yl)porphyrinato}zinc(II) (syn-1) (38.8 mg, 0.0371
mmol) and [RhCl(CO)2]2 (7.6 mg, 0.0196 mmol) were stirred
in THF (5 mL) at room temperature for 1 h. The solvent was
then removed under vacuum. The residue was recrystallized
from CH2Cl2/n-hexane to give a purple solid (2c) (9.1 mg,

Metalloporphyrin-Phosphine Hybrid Ligands
Organometallics, Vol. 23, No. 17, 2004 4017
0.0075 mmol; 20%): 1H NMR (CDCl3) δ 5.86 (t, 2H, J ) 4.8
Hz), 6.21 (br, 8H), 6.80 (dd, 2H, J ) 6.8 and 14.0 Hz), 6.93 (t,
10H, J ) 7.6 Hz), 7.10 (t, 2H, J ) 7.6 Hz), 7.68-7.89 (m, 10H),
8.41 (d, 2H, J ) 6.4 Hz), 8.63 (d, 4H, J ) 4.4 Hz), 8.89 (d, 4H,
J ) 4.4 Hz), 9.82 (s, 2H); 31P{1H} NMR (CDCl3) δ 27.5 (d, J Rh-P
) 120 Hz); IR (KBr) 1973 cm-1 ν(CdO); UV/vis (CHCl3) λmax
(log ꢀ) 424 (5.62), 550 (4.42), 624 (4.15) nm. Anal. Calcd for
was dried over anhydrous MgSO4. For the GLC analysis,
cyclododecane was added as an internal standard.
X-r a y Cr ysta llogr a p h ic Stu d ies of syn -7. Black crystals
of syn-7 suitable for X-ray analysis were obtained by recrys-
tallization from CH2Cl2/n-hexane. A single crystal was sealed
in a Pyrex glass capillary under N2 atmosphere and used for
data collection. All measurements were made on a Rigaku
RAXIS imaging plate area detector with graphite-monochro-
mated Mo KR radiation. Details of crystal and data collection
parameters are summarized in Table 4. The positions of non-
hydrogen atoms were determined by direct methods (SIR92)
and subsequent Fourier syntheses (DIRDIF99).
C
69H46ON4ClP2RhZn‚2CH2Cl2 (2c‚2CH2Cl2): C, 61.67; H, 3.64;
N, 4.05. Found: C, 61.84; H, 4.14; N, 3.83.
Gen er a l P r oced u r e for Rh od iu m - or Ir id iu m -Ca ta -
lyzed Hyd r osilyla tion of Keton es. A typical experimental
procedure for the hydrosilylation of ketones by using [RhCl-
(COD)]2 and syn-1 is as follows. In a 20 mL flask were placed
[RhCl(COD)]2 (0.001 mmol; 0.5 mol %) and syn-1 (0.002 mmol;
1 mol %) under N2. Anhydrous THF (5 mL) and then ac-
etophenone (0.02 mmol) were added. Diphenylsilane (0.60
mmol) was added slowly, and the reaction mixture was stirred
at room temperature for 24 h. Methanol (1 mL) was slowly
added, and the mixture was stirred for 1 h. After gas evolution
ceased, 1 N aqueous HCl (5 mL) was added to the reaction
mixture. The reaction mixture was washed with brine (10 mL)
and extracted with diethyl ether (10 mL × 3). The organic layer
Ack n ow led gm en t. This work was supported by a
Grant-in-Aid for Scientific Research for Young Scientists
(A) (No. 15685006) from the Ministry of Education,
Culture, Sports, Science and Technology, J apan.
Su p p or tin g In for m a tion Ava ila ble: Crystallographic
data of syn-7. This material is available free of charge via the
Internet at http://pubs.acs.org.
OM0498201