Reactivity of phosphasilametallacyclopropane toward substrates with polarized E-H bonds (E = O, N, S, and P): Formation and structures of ring-opening products

Article abstract of DOI:10.1021/om0492294

Treatment of a three-membered metallacycle Cp*(CO)Fe{k ²(Si,P)-SiMe₂PPh₂} (1) with substrates of the type R_nEH (ER_n = OH, OMe, OⁱBu, OPh, S ^pTol, NEt₂, NPhH, PPh₂, and PPhH) results in the instantaneous formation of the ring-opening products Cp*(CO)Fe- (PPh₂H)(SiMe₂ER_n). In these reactions, 1,2-additdon of the substrates occurs exclusively across the silicon-phosphorus bond in 1. The structures of the products have been unequivocally determined by spectroscopic data and X-ray diffraction analysis.

Full text of DOI:10.1021/om0492294

Organometallics 2005, 24, 659-664
659
Reactivity of Phosphasilametallacyclopropane toward
Substrates with Polarized E-H Bonds (E ) O, N, S, and
P): Formation and Structures of Ring-Opening Products
Masaaki Okazaki,*,† Kyeong A Jung, and Hiromi Tobita*
Department of Chemistry, Graduate School of Science,
Tohoku University, Sendai 980-8578, Japan
Received October 5, 2004
Treatment of a three-membered metallacycle Cp*(CO)Fe{κ2(Si,P)-SiMe2PPh2} (1) with
substrates of the type RnEH (ERn ) OH, OMe, OtBu, OPh, SpTol, NEt2, NPhH, PPh2, and
PPhH) results in the instantaneous formation of the ring-opening products Cp*(CO)Fe-
(PPh2H)(SiMe2ERn). In these reactions, 1,2-addition of the substrates occurs exclusively across
the silicon-phosphorus bond in 1. The structures of the products have been unequivocally
determined by spectroscopic data and X-ray diffraction analysis.
Introduction
total to the metal center.6 Our previous communication
described the isolation of phosphasilametallacyclopro-
pane, Cp*(CO)Fe{κ2(Si,P)-SiMe2PPh2} (1),6b which ex-
hibits unique reactivity toward molecules with a polar-
ized unsaturated bond. For example, treatment of 1 with
acetone led to insertion of the CO double bond into the
silicon-phosphorus bond to produce Cp*(CO)Fe{κ2(Si,P)-
SiMe2OCMe2PPh2}. A heteroaromatic compound, 4-(di-
methylamino)pyridine (DMAP), also reacted with 1 to
give the insertion product. The present report examines
the reactivity of 1 toward molecules with polarized E-H
single bonds (E ) O, N, S, P) such as water, alcohol,
phenol, secondary amine, aniline, thiol, and primary and
secondary phosphines. All reactions proceeded quickly
at room temperature to give the 1,2-addition products
through cleavage of the silicon-phosphorus bond.
Three-membered cyclic compounds with ring constitu-
ents of silicon and transition metal atoms have attracted
much attention with respect to bonding modes and
reactivity.1 Although several silametallacyclopropanes
have been prepared and their reactivity toward various
substrates has been investigated, there have been only
limited studies concerning the reactions between sila-
metallacyclopropane and substrates with E-H single
bonds (E ) typical elements having nonbonding electron
pairs). Berry2 and Tilley3 independently reported that
the treatment of silene complexes, LnM{κ2(C,Si)-CH2-
SiR2} (LnM ) Cp2W, Cp*(PMe3)Ir), with MeOH leads
to the selective cleavage of the metal-silicon bonds to
give Ln(H)MCH2Si(OMe)R2. Similarly, the disilene plati-
num complex (Et3P)2Pt{κ2(Si,Si)-Mes2SiSiMes2} has
been shown to react with MeOH to give (Et3P)2Pt(H)-
SiMes2SiMes2OMe through cleavage of the platinum-
silicon bond,4 while the disilene molybdenum complex
Cp2Mo{κ2(Si,Si)-Me2SiSiMe2} reacts with MeOH to give
a mixture of Cp2Mo(H)SiMe2SiMe2OMe and Cp2Mo-
(SiMe2OMe)SiMe2H in a 2:8 molar ratio by 1,2-MeOH
addition to the silicon-silicon bond.5
Results and Discussion
t
Reactions of 1 with H2O, MeOH, BuOH, PhOH,
pTolSH, Et2NH, and PhNH2. The reactions of 1 with
RnE-H (E ) O, S, and N) are illustrated in Scheme 1.
Selected infrared (IR) and nuclear magnetic resonance
(NMR) data for complexes 1-8 are listed in Table 1. In
the reactions of 1 with water, alcohols, and phenol at
room temperature, the ring-opening products 2-5 were
formed immediately and exclusively through cleavage
of the silicon-phosphorus bond. The difference between
the reaction mode between 1 and silene2,3 or disilene4,5
complexes toward MeOH is likely to reflect the highly
polarized silicon-phosphorus bond. Complex 1 also
Recently, our research has been focused on the
synthesis and properties of three-membered metalla-
cycles of the type LnM{κ2(Si,E)-SiMe2ERn}, in which the
heteroatom (E) has at least one lone pair and the
κ2(Si,E)-SiMe2ERn ligand donates three electrons in
* To whom correspondence should be addressed. E-mail: mokazaki@
scl.kyoto-u.ac.jp (M.O.); tobita@mail.tains.tohoku.ac.jp (H.T.).
† Present address: International Research Center for Elements
Science, Institute for Chemical Research, Kyoto University, Uji, Kyoto
611-0011, Japan.
p
reacted with TolSH, Et2NH, and aniline to give the
corresponding products 6-8 under the same reaction
conditions.
Pham and West reported the reaction of the disilene
complex (dppe)Pt{κ2(Si,Si)-Me2SiSiMe2} with ammonia
to give (dppe)Pt{κ2(Si,Si)-SiMe2N(H)SiMe2} in nearly
(1) (a) Eisen, M. S. In The Chemistry of Organic Silicon Compounds;
Rappoport, Z., Apeloig, Y., Eds.; Wiley: New York, 1998; Vol. 2,
Chapter 35, p 2037. (b) Tilley, T. D. In The Silicon-Heteroatom Bond;
Patai, S., Rappoport, Z., Eds.; Wiley: New York, 1991; Chapters 9,
10, pp 245, 309.
(2) Koloski, T. S.; Carroll, P. J.; Berry, D. H. J. Am. Chem. Soc. 1990,
112, 6405.
(6) (a) Okazaki, M.; Satoh, K.; Jung, K. A.; Tobita, H.; Ogino, H.
Organometallics 2004, 23, 1971. (b) Okazaki, M.; Jung, K. A.; Satoh,
K.; Okada, H.; Naito, J.; Akagi, T.; Tobita, H.; Ogino, H. J. Am. Chem.
Soc. 2004, 126, 5060. (c) Okada, H.; Okazaki, M.; Tobita, H.; Ogino,
H. Chem. Lett. 2003, 32, 876. (d) Okazaki, M.; Jung, K. A.; Tobita, H.
Chem. Commun., in press.
(3) Campion, B. K.; Heyn, R. H.; Tilley, T. D. J. Am. Chem. Soc.
1990, 112, 4079.
(4) Pham, E. K.; West, R. Organometallics 1990, 9, 1517.
(5) Berry, D. H.; Chey, J.; Zipin, H. S.; Carroll, P. J. Polyhedron
1991, 10, 1189.
10.1021/om0492294 CCC: $30.25 © 2005 American Chemical Society
Publication on Web 01/19/2005

660 Organometallics, Vol. 24, No. 4, 2005
Okazaki et al.
Scheme 1. Reactions of 1 with RnE-H (RnE ) OH, OMe, OtBu, OPh, SpTol, NEt2, NHPh)
Table 1. Selected IR and NMR Data for 1-10
complex
IR (νCO), cm-1
1H NMR δ PH
29Si NMR δ
31P NMR δ
16b
2
1894
1897
1896
1894
1900
1901
1890
1898
1898
25.4 (d, 1JPSi ) 125.5 Hz)
71.0 (d, 2JPSi ) 40.5 Hz)
73.5 (d, 2JPSi ) 42.1 Hz)
59.6 (d, 2JPSi ) 45.3 Hz)
76.4 (d, 2JPSi ) 42.3 Hz)
64.4 (d, 2JPSi ) 42.9 Hz)
53.8 (d, 2JPSi ) 39.7 Hz)
50.9 (d, 2JPSi ) 42.3 Hz)
45.6 (dd, 1JPSi ) 83.4 Hz,
2JPSi ) 40.3 Hz)
-48.3
63.5
61.4
59.2
61.3
60.9
59.5
58.8
6.62 (d, 1JPH ) 343.5 Hz)
6.67 (d, 1JPH ) 347.0 Hz)
6.87 (d, 1JPH ) 354.3 Hz)
6.67 (d, 1JPH ) 347.1 Hz)
6.89 (d, 1JPH ) 349.2 Hz)
6.68 (d, 1JPH ) 356.7 Hz)
6.73 (d, 1JPH ) 349.8 Hz)
6.67 (dd, 1JPH ) 346.0 Hz,
4JPH ) 1.8 Hz)
3
4
5
6
7
8
9
-31.9 (d, 3JPP ) 15.2 Hz, SiPPh2)
66.1 (d, 3JPP ) 15.2 Hz, PPh2H)
-100.6 (d, 3JPP ) 7.3 Hz, SiPPhH)
10
1901
3.48 (d, 1JPH ) 204.0, SiPH)
41.4 (dd, 1JPSi ) 73.3 Hz,
2JPSi ) 38.8 Hz)
3.83 (d, 1JPH ) 203.7, SiPH)
-98.7 (d, 3JPP ) 18.2 Hz, SiPPhH)
58.6 (d, 3JPP ) 7.3 Hz, PPh2H)
6.69 (d, 1JPH ) 348.6 Hz, PPh2H)
42.4 (dd, 1JPSi ) 67.3 Hz,
2JPSi ) 39.5 Hz)
6.79 (d, 1JPH ) 350.1 Hz, PPh2H)
58.7 (d, 3JPP ) 18.2 Hz, PPh2H)
quantitative yield.4 Although the authors did not men-
tion the reaction mechanism, it is believed that the reac-
tion could proceed via the transient formation of (dppe)-
Pt(SiMe2H)(SiMe2NH2), corresponding to complex 7.
In accordance with the cleavage of the three-mem-
bered-ring structure, the signals in the 29Si and 31P
NMR spectra were significantly downfield-shifted com-
pared to those for 1.7 The signals of the incorporated
acetone to give the insertion product.6b We have pro-
posed a mechanism involving the attack of the nucleo-
philes to 1 to give base-stabilized silylene complexes,
followed by the nucleophilic attack of the phosphido
ligand toward the R-carbon of the coordinated DMAP
and acetone. The formation of 2-8 can also be reason-
ably explained by assuming the generation of the base-
1
RnE-H fragments were reasonably assigned in the H
NMR spectra. Typically, in complex 2, the 1H NMR
signals assigned to the SiOH and PH fragments were
1
observed at 0.88 (s) and 6.62 (d, JPH ) 343.5 Hz),
respectively.
The molecular structures of 2, 3, 5, and 6 are shown
in Figures 1, 2, 3, and 4, respectively. These complexes
adopt the normal three-legged piano-stool geometry.
Besides the Cp* and CO ligands, the iron center
possesses the SiMe2ERn (ERn ) OH, OMe, OPh, SpTol)
and PPh2H ligands formed through the addition of
RnE-H across the silicon-phosphorus bond. The iron-
silicon bond is shorter than the typical iron-silicon
single bonds in LnFeSiR3 (R ) alkyl or aryl), but is
comparable to those in heteroatom-substituted silyliron
complexes.1 The shortening is due to back-donation from
the iron dπ orbital to the σ* orbital of the Si-E bond.
Our previous communications demonstrated that 1
reacted with 4-(dimethylamino)pyridine (DMAP) or
Figure 1. Molecular structure of 2 at the 50% probability
level. Selected bond lengths (Å) and angles (deg): Fe-P )
2.1632(11), Fe-Si ) 2.3196(12), Fe-C1 ) 1.738(4), C1-
O1 ) 1.161(5), Si-O2 ) 1.685(3), P-H1 ) 1.39(5), O2-
H2 ) 0.81(6), C1-Fe-P ) 95.69(13), C1-Fe-Si ) 81.80-
(12), P-Fe-Si ) 95.15(4).
(7) The 29Si or 31P NMR signal of a silicon or phosphorus atom in a
three-membered metallacycle shows typical upfield shift: (a) Garrou,
P. E. Chem. Rev. 1981, 81, 229. (b) Lindner, E.; Fawzi, R.; Mayer, H.
A.; Eichele, K.; Hiller, W. Organometallics 1992, 11, 1033.

Reactivity of Phosphasilametallacyclopropane
Organometallics, Vol. 24, No. 4, 2005 661
Figure 4. Molecular structure of 6 at the 50% probability
level. Selected bond lengths (Å) and angles (deg): Fe-P )
2.1603(16), Fe-Si ) 2.2992(16), Fe-C1 ) 1.721(6), C1-
O1 ) 1.150(7), Si-S ) 2.189(2), S-C4 ) 1.773(5), P-H1
) 1.44(5), C1-Fe-P ) 94.92(19), C1-Fe-Si ) 83.65(18),
P-Fe-Si ) 92.24(6), S-Si-Fe ) 105.13(7).
Figure 2. Molecular structure of 3 at the 50% probability
level. Selected bond lengths (Å) and angles (deg): Fe-P )
2.1535(9), Fe-Si ) 2.3169(9), Fe-C1 ) 1.722(3), C1-O1
) 1.171(4), O2-C4 ) 1.397(4), Si-O2 ) 1.686(2), P-H1 )
1.33(3), C1-Fe-P ) 93.64(10), C1-Fe-Si ) 84.77(10),
P-Fe-Si ) 93.08(3).
Scheme 2 Plausible Formation Mechanism of 2-8
appears at δ -44.1,6b these two doublet signals can be
assigned to the SiPPh2 and PPh2H fragments, respec-
tively.
Figure 3. Molecular structure of 5 at the 50% probability
level. Selected bond lengths (Å) and angles (deg): Fe-P )
2.1571(5), Fe-Si ) 2.2947(5), Fe-C1 ) 1.7263(17), C1-
O1 ) 1.166(2), O2-C4 ) 1.3551(19), Si-O2 ) 1.7034(13),
P-H1 ) 1.30(2), C1-Fe-P ) 96.64(6), C1-Fe-Si )
82.05(5), P-Fe-Si ) 94.053(17).
The formation of 9, in addition to the mechanism
shown in Scheme 2, can be explained by considering the
validity of an alternative mechanism involving the
coordination of PPh2H to the iron center through cleav-
age of the iron-phosphorus bond. To clarify the mech-
anism, 1 was reacted with PPhH2. This reaction also
proceeded quickly at room temperature to give 10 as a
1:1 mixture of two diastereomers in 77% isolated yield
(eq 2). One of the diastereomers was unequivocally
determined by X-ray diffraction analysis (Figure 5).
Besides the Cp* and CO ligands, the iron center
possesses the SiMe2P(H)Ph and PPh2H ligands, clearly
indicating that complexes 9 and 10 were formed through
1,2-additon of the phosphorus-hydrogen bonds across
the phosphorus-silicon bond. Thus, the alternative
mechanism mentioned above can be ruled out.
stabilized silylene complexes (Scheme 2).8 The lone pair
of the phosphido ligand then attacks the proton of the
coordinated molecule to give the products. An alterna-
tive concerted mechanism involving an Si-P-H-E
four-membered ring transition state, however, cannot
be ruled out.
Reactions of 1 with Secondary and Primary
Phosphines. Treatment of 1 with PPh2H led to the
1
formation of 9 in 71% isolated yield (eq 1). In the H
NMR spectrum, the signal of the PH fragment was
observed at δ 6.67 as a doublet of doublets (1JPH ) 346.0
4
Hz, JPH ) 1.8 Hz). A doublet of doublets was also
observed in the 29Si NMR spectrum at δ 45.6 (1JPSi
)
83.4 Hz, 2JPSi ) 40.3 Hz). Furthermore, in the 31P{1H}
NMR spectrum, two coupled doublets were observed at
δ -31.9 and 66.1 with a coupling constant of JPP ) 15.2
Hz. As the 31P NMR signal of Cp*(CO)2SiMe2PPh2
Conclusion
The reactions of phosphasilametallacyclopropane 1
t
with water, MeOH, BuOH, PhOH, pTolSH, Et2NH,
(8) (a) Ogino, H. Chem. Rec. 2002, 2, 291. (b) Okazaki, M.; Tobita,
H.; Ogino, H. Dalton Trans. 2003, 493.
PhNH2, Ph2PH, and PhPH2 were shown to proceed

662 Organometallics, Vol. 24, No. 4, 2005
Okazaki et al.
C, 62.50; H, 6.92. Found: C, 62.57; H, 7.06. EI-MS (70 eV):
m/z 480 (M+, 6), 451 (M+ - CO - H, 10), 404 (M+ - C2H8OSi,
1
100). H NMR (300 MHz, benzene-d6): δ 0.47, 0.63 (s, 3H ×
2, SiMe2), 0.88 (s, 1H, OH), 1.57 (s, 15H, Cp*), 6.62 (d, 1JPH
)
343.5 Hz, 1H, PH), 6.95-7.09 (m, 6H, m,p-Ph), 7.47-7.59 (m,
4H, o-Ph). 13C{1H} NMR (75.5 MHz, dichloromethane-d2): δ
9.0, 9.2 (SiMe2), 9.8 (C5Me5), 91.8 (C5Me5), 128.2 (d, 3JPC ) 9.8
Hz, m-Ph), 128.4 (d, 3JPC ) 9.1 Hz, m-Ph), 129.4 (d, 4JPC ) 2.3
Hz, p-Ph × 2), 132.5 (d, 2JPC ) 9.8 Hz, o-Ph), 132.9 (d, 2JPC
)
9.8 Hz, o-Ph), 134.9 (d, 1JPC ) 38.5 Hz, ipso-Ph), 135.9 (d, 1JPC
2
) 41.5 Hz, ipso-Ph), 220.0 (d, JPC ) 22.7 Hz, CO).
Reaction of 1 with MeOH. Complex 3 (20 mg) was
synthesized as an orange powder in 98% yield by a method
similar to that for 2, using 1 (19 mg, 0.041 mmol) and an excess
of methanol (100 µL). Anal. Calcd for C26H35FeO2PSi: C, 63.16;
H, 7.13. Found: C, 63.17; H, 7.18. EI-MS (70 eV): m/z 494
Figure 5. Molecular structure of 10 at the 50% probability
level. Selected bond lengths (Å) and angles (deg): Fe-P2
) 2.1673(16), Fe-Si ) 2.3212(17), Fe-C1 ) 1.737(6), P1-
Si ) 2.305(2), C1-O1 ) 1.158(7), P1-H1 ) 1.26(7), P2-
H2 ) 1.31(5), C1-Fe-P2 ) 96.5(2), C1-Fe-Si ) 82.86(19),
P2-Fe-Si ) 91.64(6), Fe-Si-P1 ) 111.14(8).
(M+, 4), 479 (M+ - Me, 3), 451 (M+ - Me - CO, 6), 435 (M+
-
1
OMe - CO, 5). H NMR (300 MHz, benzene-d6): δ 0.45, 0.56
3
(s, 3H × 2, SiMe2), 1.58 (d, JPC ) 0.6 Hz, 15H, Cp*), 3.48 (s,
1
3H, OMe), 6.67 (d, JPH ) 347.0 Hz, 1H, PH), 6.96-7.09 (m,
6H, m,p-Ph), 7.49-7.58 (m, 4H, o-Ph). 13C{1H} NMR (75.5
MHz, dichloromethane-d2): δ 4.6, 5.4 (SiMe2), 9.8 (C5Me5), 49.9
3
(OCH3), 91.8 (C5Me5), 128.0 (d, JPC ) 9.1 Hz, m-Ph × 2),
129.10 (d, 4JPC ) 2.6 Hz, p-Ph), 129.13 (d, 4JPC ) 2.3 Hz, p-Ph),
immediately at room temperature to give the corre-
sponding 1,2-additon products through cleavage of the
silicon-phosphorus bond. Cleavage of the iron-silicon
or iron-phosphorus bond was not observed in any of
these reactions. To the best of the authors’ knowledge,
the carbon analogue of 1, phosphametallacyclopropapne,
does not exhibit this type of reactivity toward substrates
with polarized E-H bonds.9 Thus, the novel reactivity
of phosphasilametallacyclopropane is attributable to the
highly polarized silicon-phosphorus bond.
2
2
132.9 (d, JPC ) 9.7 Hz, o-Ph), 133.0 (d, JPC ) 9.7 Hz, o-Ph),
134.7 (d, JPC ) 38.0 Hz, ipso-Ph), 135.5 (d, JPC ) 40.2 Hz,
1
1
2
ipso-Ph), 220.3 (d, JPC ) 22.5 Hz, CO).
Reaction of 1 with tBuOH. Complex 4 (17 mg) was
synthesized as an orange powder in 81% yield by a method
similar to that for 2, using 1 (18 mg, 0.039 mmol) and an excess
of tert-butyl alcohol (200 µL). Anal. Calcd for C29H41FeO2PSi:
C, 64.92; H, 7.70. Found: C, 64.92; H, 7.67. EI-MS (70 eV):
m/z 536 (M+, 1), 507 (M+ - CO - H, 1), 404 (M+ - C6H16OSi,
51), 376 (M+ - C7H16O2Si, 100). 1H NMR (300 MHz, benzene-
t
d6): δ 0.63, 0.77 (s, 3H × 2, SiMe2), 1.36 (s, 9H, Bu), 1.60 (s,
1
15H, Cp*), 6.87 (d, JPH ) 354.3 Hz, 1H, PH), 7.01-7.12 (m,
Experimental Section
6H, m,p-Ph), 7.49-7.66 (m, 4H, o-Ph). 13C{1H} NMR (75.5
MHz, dichloromethane-d2): δ 9.9 (C5Me5), 10.5, 10.6 (SiMe2),
General Procedures. All manipulations were carried out
under a dry nitrogen atmosphere. Reagent-grade hexane and
pentane were distilled from sodium-benzophenone ketyl im-
mediately prior to use. Benzene-d6 was dried over a potassium
mirror and transferred to an NMR tube under vacuum.
Dichloromethane-d2 was distilled from CaH2, dried over a
molecular sieves (3 Å), and transferred to an NMR tube under
vacuum. Methanol was distilled from Mg(OMe)2 and stored
3
32.2 (CMe3), 73.0 (CMe3), 91.6 (C5Me5), 127.7 (d, JPC ) 9.1
Hz, m-Ph), 128.0 (d, 3JPC ) 9.8 Hz, m-Ph), 129.0 (d, 4JPC ) 1.5
4
2
Hz, p-Ph), 129.2 (d, JPC ) 1.5 Hz, p-Ph), 133.5 (d, JPC ) 9.8
Hz, o-Ph), 133.7 (d, 2JPC ) 9.8 Hz, o-Ph), 134.2 (d, 1JPC ) 36.2
Hz, ipso-Ph), 135.0 (d, 1JPC ) 38.5 Hz, ipso-Ph), 220.1 (d, 2JPC
) 23.4 Hz, CO).
Reaction of 1 with PhOH. Complex 5 (31 mg) was
synthesized as an orange powder in 74% yield by a method
similar to that for 2, using 1 (35 mg, 0.076 mmol) and PhOH
(7.0 mg, 0.074 mmol). Anal. Calcd for C31H37FeO2PSi: C, 66.90;
H, 6.70. Found: C, 66.82; H, 6.82. EI-MS (70 eV): m/z 556
(M+, 1), 528 (M+ - CO, 1), 404 (M+ - C8H12OSi, 78), 376 (M+
- C9H12O2Si, 100). 1H NMR (300 MHz, benzene-d6): δ 0.50
(s, 3H, SiMe2), 0.63 (d, 4JPH ) 0.6 Hz, 3H, SiMe), 1.58 (d, 3JPH
) 0.9 Hz, 15H, Cp*), 6.67 (d, 1JPH ) 347.1 Hz, 1H, PH), 6.85-
6.91 (m, 2H, Ph), 6.96-7.11 (m, 6H, Ph), 7.18-7.24 (m, 3H,
Ph), 7.46-7.59 (m, 4H, Ph). 13C{1H} NMR (75.5 MHz, dichlo-
romethane-d2): δ 6.5, 7.4 (SiMe2), 9.8 (C5Me5), 92.1 (C5Me5),
t
in the presence of molecular sieves 3 Å. BuOH was distilled
from CaH2 and stored in the presence of molecular sieves 4 Å.
pTolSH was purified by recrystallization from pentane. NEt2H
and aniline were distilled from KOH and CaH2, respectively,
11
prior to use. PPh2H10 and PPhH2 were prepared according
to literature methods. Other chemicals were purchased and
used as received. NMR data were recorded on a Bruker ARX-
300 or AV-300 spectrometer. 29Si NMR spectra were obtained
using the DEPT pulse sequence technique. IR spectra were
recorded on a Horiba FT-200 spectrometer. Mass spectral data
were obtained using a JEOL JMS-HX110 or Hitachi M2500S
spectrometer.
Reaction of 1 with H2O. A Pyrex tube (20 mm o.d.)
equipped with a greaseless vacuum valve and a stirrer bar
was charged with 1 (19 mg, 0.041 mmol), pentane (5 mL), and
an excess of H2O (20 µL) in this order under high vacuum by
the trap-to-trap transfer technique. The reaction mixture was
then stirred at room temperature for 30 min. Subsequent
removal of volatiles gave spectroscopically pure 2 as an orange
powder. Yield: 16 mg (81%). Anal. Calcd for C25H33FeO2PSi:
3
119.6 (p-OPh), 120.7 (m-OPh), 128.15 (d, JPC ) 9.1 Hz,
m-PPh), 128.21 (d, 3JPC ) 9.8 Hz, m-PPh), 128.9 (o-OPh), 129.3
(d, 4JPC ) 2.3 Hz, p-PPh), 129.4 (d, 4JPC ) 3.0 Hz, p-PPh), 133.0
(d, 2JPC ) 10.6, o-PPh). 133.2 (d, 2JPC ) 11.3 Hz, o-PPh), 134.3
1
1
(d, JPC ) 37.8 Hz, ipso-PPh), 135.2 (d, JPC ) 40.8 Hz, ipso-
2
PPh), 157.6 (ipso-OPh), 220.0 (d, JPC ) 22.7 Hz, CO).
Reaction of 1 with pTolSH. Complex 6 (34 mg) was
synthesized as an orange powder in 81% yield by a method
similar to that for 2, using 1 (33 mg, 0.071 mmol) and pTolSH
(9.0 mg, 0.072 mmol). Anal. Calcd for C32H39FeOPSSi‚1/2C5H12:
C, 66.54; H, 7.28. Found: C, 66.19; H, 7.34. EI-MS (70 eV):
m/z 586 (M+, 1), 558 (M+ - CO, 1), 557 (M+ - CO - H, 1), 404
(M+ - SiMe2SpTol-H, 47), 376 (M+- SiMe2SpTol-H - CO, 100).
1H NMR (300 MHz, benzene-d6): δ 0.33, 066 (s, 3H × 2, SiMe2),
1.63 (s, 15H, Cp*), 2.07 (s, 3H, C6H4Me), 6.89 (d, 1JPH ) 349.2
(9) (a) AI-Jibori, S.; Crocker, C.; McDonald, W. S.; Shaw, B. L. J.
Chem. Soc., Dalton Trans. 1981, 1572. (b) Karsch, H. H.; Deubelly,
B.; Hofmann, J.; Pieper, U.; Mu¨ller, G. J. Am. Chem. Soc. 1988, 110,
3654, and references therein.
(10) Bianco, V. D.; Doronzo, S. Inorg. Synth. 1974, 16, 161.
(11) Pass, F.; Schindlbauer, H. Monatsh. Chem. 1959, 90, 148.

Reactivity of Phosphasilametallacyclopropane
Organometallics, Vol. 24, No. 4, 2005 663
Table 2. Crystallographic Details of 2, 3, 5, 6, and 10
2
3
5
6‚1/2C5H12
10
cryst size, mm
formula
fw
cryst syst
space group
a, Å
0.20 × 0.15 × 0.10
0.20 × 0.15 × 0.05
C26H35FeO2PSi
494.45
0.45 × 0.40 × 0.40
C31H37FeO2PSi
556.52
0.30 × 0.20 × 0.10
C34.5H39FeOPSSi
616.63
0.25 × 0.15 × 0.15
C31H38FeOP2Si
572.49
C25H33FeO2PSi
480.42
P1h
C2/c
P21/c
P1h
P21/a
triclinic
8.9347(16)
9.4342(18)
14.924(3)
99.724(14)
102.811(11)
99.590(6)
1181.4(4)
2
monoclinic
17.8808(5)
8.6468(3)
32.4251(11)
90
89.3244(14)
90
monoclinic
17.2616(8)
8.8862(6)
18.9897(14)
90
104.388(2)
90
triclinic
monoclinic
14.2343(7)
12.7285(6)
16.3992(8)
90
92.0787(10)
90
11.564(3)
12.333(4)
12.706(3)
73.972(12)
80.424(8)
68.804(9)
1619.4(7)
2
b, Å
c, Å
R, deg
â, deg
γ, deg
volume, Å3
Z
5013.0(3)
8
2821.5(3)
4
2969.3(2)
4
F
calc, g cm-3
1.351
1.310
1.310
1.265
1.281
µ, mm-1
0.776
0.733
0.660
0.642
0.678
F(000)
508
2096
1176
650
1208
no. of reflns collected
no. of indep reflns
10 010
15 055
23 123
9450
22 209
5133 [R(int) )
0.0587]
4407 [R(int) )
0.0317]
6383 [R(int) )
0.0319]
5284 [R(int) )
0.0567]
5238 [R(int) )
0.1050]
max. and min. transmn
no. of data/restraints/
params
0.9264 and 0.8603
5133/0/286
0.9642 and 0.8672
4407/0/292
0.7782 and 0.7556
6383/0/336
0.9386 and 0.8308
5284/0/359
0.9051 and 0.8488
5238/0/477
GOF on F2
1.160
1.213
1.091
1.168
1.278
final R indices [I > 2σ(I)]
R1 ) 0.0594,
wR2 ) 0.1376
R1 ) 0.0783,
wR2 ) 0.1471
0.676 and -0.405
R1 ) 0.0459,
wR2 ) 0.0836
R1 ) 0.0567,
wR2 ) 0.0870
0.303 and -0.305
R1 ) 0.0354,
wR2 ) 0.0837
R1 ) 0.0410,
wR2 ) 0.0872
0.701 and -0.263
R1 ) 0.0680,
wR2 ) 0.1496
R1 ) 0.0929,
wR2 ) 0.1679
0.680 and -0.521
R1 ) 0.0832,
wR2 ) 0.1384
R1 ) 0.1122,
wR2 ) 0.1479
0.427 and -0.495
R indices (all data)
largest diff peak and
hole, e‚Å-3
Hz, 1H, PH), 6.90-7.11 (m, 8H, m,p-PPh2, C6H4Me), 7.58-
7.71 (m, 6H, o-PPh2, C6H4Me). 13C{1H} NMR (75.5 MHz,
dichloromethane-d2): δ 5.6 (d, 3JPC ) 2.3 Hz, SiMe), 7.2 (SiMe),
10.1 (C5Me5), 34.1 (C6H4Me), 92.6 (C5Me5), 128.1 (d, 3JPC ) 9.1
methane-d2): δ 5.9, 6.5 (SiMe2), 9.9 (C5Me5), 92.0 (C5Me5),
115.6 (p-NPh), 116.0 (m-NPh), 128.2 (d, 3JPC ) 9.1 Hz, m-PPh),
128.3 (d, 3JPC ) 8.3 Hz, m-PPh), 128.8 (o-NPh), 129.4 (d, 4JPC
4
) 2.3 Hz, p-PPh), 129.5 (d, JPC ) 2.3 Hz, p-PPh), 132.9 (d,
3
2
Hz, m-PPh), 128.2 (d, JPC ) 9.1 Hz, m-PPh), 128.8 (m-pTol),
2JPC ) 9.1 Hz, o-PPh), 133.3 (d, JPC ) 9.8 Hz, o-PPh), 134.2
4
129.3 (d, JPC ) 2.3 Hz, p-PPh), 129.3 (br s, p-PPh), 132.3 (p-
(d, 1JPC ) 38.5 Hz, ipso-PPh), 134.3 (d, 1JPC) 40.2, ipso-PPh),
pTol), 133.3 (d, 2JPC ) 9.8 Hz, o-PPh), 133.6 (d, 2JPC ) 9.1 Hz,
149.4 (ipso-NPh), 219.9 (d, JPC ) 21.9 Hz, CO).
2
1
1
o-PPh), 134.3 (d, JPC ) 37.8 Hz, ipso-PPh), 134.96 (d, JPC
)
Reaction of 1 with Ph2PH. Complex 9 was synthesized
by a method similar to that for 2, using 1 (28 mg, 0.061 mmol)
and Ph2PH (12 mg, 0.064 mmol). Recrystallization from
pentane at -30 °C gave yellow crystals of 9. Yield: 28 mg
(71%). Anal. Calcd for C37H42FeOP2Si: C, 68.52; H, 6.53.
Found: C, 68.60; H, 6.49. EI-MS (70 eV): m/z 462 (M+ - Ph2-
PH, 9), 404 (M+ - Ph2PH - SiMe2, 34), 376 (M+ - Ph2PH -
SiMe2 - CO, 100). 1H NMR (300 MHz, cyclohexane-d12): δ 0.03
(d, 3JPH ) 3.2 Hz, SiMe), 0.10 (d, 3JPH ) 4.6 Hz, SiMe), 1.63 (s,
15H, Cp*), 6.67 (dd, 1JPH ) 346.0 Hz, 4JPH ) 1.8 Hz, 1H, PH),
6.98-7.12 (m, 6H, m,p-Ph), 7.12-7.22 (m, 6H, m,p-Ph), 7.28-
43.8 Hz, ipso-PPh), 135.01 (o-pTol), 135.3 (ipso-pTol), 219.3 (d,
2JPC ) 21.1 Hz, CO).
Reaction of 1 with Et2NH. Complex 7 (34 mg) was
synthesized as an orange powder in 100% yield by a method
similar to that for 2, using 1 (29 mg, 0.063 mmol) and an excess
of NEt2H (100 µL). Anal. Calcd for C29H42FeNOPSi: C, 65.04;
H, 7.90; N, 2.62. Found: C, 64.30; H, 7.86; N, 1.90. EI-MS (70
eV): m/z 535 (M+, 0.1), 462 (M+ - HNEt2, 2), 404 (M+ - SiMe2-
NEt2 - H, 47), 376 (M+ - SiMe2NEt2 - H - CO, 100). 1H NMR
(300 MHz, benzene-d6): δ 0.56, 0.63 (s, 3H × 2, SiMe2), 1.10
3
(t, JHH ) 7.1 Hz, 6H, CH2CH3), 1.56 (d, 15H, Cp*), 3.02 (q,
7.42 (m, 4H, o-Ph), 7.43-7.55 (m, 4H, o-Ph). 13C{1H} NMR
1
2
3JHH ) 7.1 Hz, 4H, CH2CH3), 6.68 (d, JPH ) 356.7 Hz, 1H,
(75.5 MHz, cyclohexane-d12): δ 4.5 (m, SiMe), 4.8 (dd, JPC
)
PH), 6.94-7.10 (m, 6H, m,p-Ph), 7.40-7.58 (m, 4H, o-Ph). 13C-
8.7 Hz, JPC ) 3.3 Hz, SiMe), 10.8 (d, JPC ) 5.9 Hz, C5Me5),
92.8 (C5Me5), 126.8 (Ph), 127.9 (d, JPC ) 6.7 Hz, Ph), 128.5 (d,
JPC ) 9.8 Hz, Ph), 128.6 (d, JPC ) 10.0 Hz, Ph), 129.6 (d, JPC
) 3.3 Hz, Ph), 133.8 (d, JPC ) 9.6 Hz, Ph), 134.0 (d, JPC ) 9.7
Hz, Ph), 134.6 (d, JPC ) 17.2 Hz, Ph), 135.7 (d, JPC ) 35.1 Hz,
Ph), 136.7 (d, JPC ) 41.6 Hz, Ph), 140.1 (m, Ph), 220.9 (d, 2JPC
) 23.6 Hz, CO).
3
3
3
{1H} NMR (75.5 MHz, cyclohexane-d12): δ 7.8 (d, JPC ) 1.1
Hz, SiMe), 7.9 (SiMe2), 10.6 (C5Me5), 15.8 (NCH2CH3), 42.2
(NCH2CH3), 92.0 (C5Me5), 128.3 (d, 3JPC ) 7.6 Hz, m-Ph), 128.4
(d, 3JPC ) 6.8 Hz, m-Ph), 129.2 (d, 4JPC ) 2.2 Hz, p-Ph), 129.6
2
2
(p-Ph), 133.4 (d, JPC ) 9.8 Hz, o-Ph), 134.6 (d, JPC ) 10.6
1
1
Hz, o-Ph), 135.4 (d, JPC ) 33.3 Hz, ipso-Ph), 137.8 (d, JPC
39.3 Hz, ipso-Ph), 220.1 (d, JPC ) 25.3 Hz, CO).
)
2
Reaction of 1 with PhPH2. Complex 10 was synthesized
by a method similar to that for 2, using 1 (58 mg, 0.13 mmol)
and PhPH2 (50 µL). Recrystallization from pentane at -30 °C
gave yellow crystals of 10. Yield: 55 mg (77%). Complex 10
consists of two diastereomers in a 1:1 molar ratio. Anal. Calcd
for C31H38FeOP2Si: C, 65.03; H, 6.69. Found: C, 65.25; H, 6.91.
EI-MS (70 eV): m/z 571 (M+ - H, 1), 462 (M+ - PhPH2, 12),
404 (M+ - PhPH2 - SiMe2, 17), 376 (M+ - PhPH2 - SiMe2 -
CO, 33). 1H NMR (300 MHz, benzene-d6): δ 0.19 (s, 3H, SiMe),
Reaction of 1 with PhNH2. Complex 8 (30 mg) was
synthesized as an orange powder in 83% yield by a method
similar to that for 2, using 1 (30 mg, 0.065 mmol) and excess
PhNH2 (50 µL). Anal. Calcd for C31H38FeNOPSi: C, 67.02; H,
6.89; N, 2.52. Found: C, 67.53; H, 7.34; N, 2.36. EI-MS (70
eV): m/z 553 (M+ - 2H, 2), 525 (M+ - CO - 2H, 2), 462 (M+
- C6H7N, 12), 404 (M+ - C8H13SiN, 42), 376 (M+ - C9H13-
SiON, 58). 1H NMR (300 MHz, benzene-d6): δ 0.74 (d, 4JPH
1.1 Hz, SiMe), 0.76 (s, 3H, SiMe), 1.49 (s, 15H, Cp*), 3.50 (s,
)
3
0.37 (d, JPH ) 7.2 Hz, 3H, SiMe), 0.40 (s, 3H, SiMe), 0.61 (d,
1
3
1H, NH), 6.73 (d, JPH ) 349.8 Hz, 1H, PH), 6.78 (t, JHH
)
3JPH ) 6.3 Hz, 3H, SiMe), 1.57 (s, 15H, Cp*), 1.60 (s, 15H,
Cp*), 3.48 (d, 1JPH ) 204.0 Hz, 1H, SiPH), 3.83 (d, 1JPH ) 203.7
Hz, 1H, SiPH), 6.69 (d, 1JPH ) 348.6 Hz, 1H, PPh2H), 6.79 (d,
1JPH ) 350.1 Hz, 1H, PPh2H), 6.95-7.13 (m, 18H, Ph), 7.38-
7.4 Hz, 1H, p-NPh), 6.85 (d, 3JHH ) 7.4 Hz, 2H, o-NPh), 6.95-
3
7.07 (m, 6H, m,p-PPh), 7.24 (t, JHH ) 7.4 Hz, 2H, m-NPh),
7.38-7.57 (m, 4H, o-PPh). 13C{1H} NMR (75.5 MHz, dichloro-

664 Organometallics, Vol. 24, No. 4, 2005
Okazaki et al.
7.59 (m, 12H, Ph). 13C{1H} NMR (75.5 MHz, cyclohexane-
The structure was solved by Patterson and Fourier transform
methods using SHELXS-9712 and refined by full matrix least-
squares techniques on all F2 data (SHELXL-97).13 In each
complex, the hydrogen atom on the phosphorus and nitrogen
atoms were located by the differential Fourier map and refined
isotropically.
d12): δ 1.3 (SiMe), 3.2 (d, JPC ) 15.1 Hz, SiMe), 4.5 (d, JPC
)
15.9 Hz, SiMe), 5.6 (dt, JPC ) 17.4 Hz, JPC ) 3.4 Hz, SiMe),
10.80 (C5Me5), 10.84 (d, JPC ) 5.3 Hz, C5Me5), 92.5 (C5Me5),
3
92.6 (C5Me5), 125.56 (Ph), 125.61 (Ph), 127.88 (d, JCP ) 6.0
Hz, Ph), 127.96 (d, 3JCP ) 5.3 Hz, Ph), 128.4 (d, 3JCP ) 8.3 Hz,
Ph), 128.5 (d, 3JPC ) 7.6 Hz, Ph), 128.6 (d, 3JCP ) 8.3 Hz, Ph),
2
2
129.6 (d, JCP ) 1.7 Hz, Ph), 129.7 (Ph), 129.8 (d, JCP ) 2.3
Hz, Ph), 129.9 (Ph), 133.7 (d, 2JCP ) 9.1 Hz, Ph), 134.1 (d, 2JCP
) 10.6 Hz, Ph), 134.29 (d, 2JCP ) 14.3 Hz, Ph), 134.33 (d, 2JCP
Acknowledgment. This work was supported by
Grants-in-Aid for Scientific Research (Nos. 14044010,
14078202, 14204065, and 15655017) from the Ministry
of Education, Culture, Sports, Science and Technology
of Japan.
) 10.4 Hz, Ph), 134.4 (d, 2JCP ) 15.9 Hz, Ph), 134.9 (d, 1JCP
)
)
)
)
1
1
18.4 Hz, Ph), 135.4 (d, JCP ) 34.5 Hz, Ph), 135.7 (d, JCP
1
1
18.4 Hz, Ph), 136.4 (d, JPC ) 37.8 Hz, Ph), 138.3 (d, JCP
1
2
25.7 Hz, Ph), 138.4 (d, JCP ) 26.0 Hz, Ph), 219.5 (d, JCP
2
Supporting Information Available: This material is
available free of charge via the Internet at http://pubs.acs.org.
22.3 Hz, CO), 219.6 (d, JCP ) 23.1 Hz, CO).
X-ray Diffraction Analysis. Single crystals of 2, 3, 5, 6‚
1/2C5H12, and 10 were obtained by cooling the solutions at -30
°C. Intensity data were collected on a RIGAKU RAXIS-RAPID
imaging plate diffractometer with graphite-monochromated
Mo KR radiation at 150 K. The data were corrected for Lorentz
and polarization effects, and numerical absorption corrections
were applied. The crystallographic data are listed in Table 2.
OM0492294
(12) Sheldrick, G. M. SHELXS-97, Programs for Solving X-ray
Crystal Structures; University of Go¨ttingen, 1997.
(13) Sheldrick, G. M. SHELXL-97, Programs for Refining X-ray
Crystal Structures; University of Go¨ttingen, 1997.