Formation of azabutadienyl fragments by addition of the isopropenyl substituent of a phosphine to benzonitriles, promoted by an osmium center

Article abstract of DOI:10.1021/om049178a

Complex Os(η⁵-C₅H₅) Cl{[η²-CH₂=C(CH₃)]PⁱPr ₂} (1) reacts with ρ-tolunitrile, benzonitrile, and ρ-chlorobenzonitrile to give the corresponding iminophosphine derivatives Os(η⁵-C₅H₅)-Cl{NH=C(ρ-C ₆H₄R)CH=C(CH₃)PⁱPr₂} (R = CH₃ (2), H (3), Cl (4)), as a result of the insertion of the carbon-nitrogen triple bond of the nitriles into one of the C(sp²)-H bonds of the phosphine of 1. Treatment of 2-4 with NaBH₄ and methanol produces the rupture of the P - C(CH₃) bond of the iminophosphine ligands and the formation of the respective osmapyrrole derivatives Os(η⁵-C₅H₅){NH-C(ρ-C₆H ₄R)-CH-C(CH₃)}(PHⁱPr₂) (R = CH ₃ (5), H (6), Cl (7)). The addition of HBF₄-Et ₂O to the diethyl ether solutions of 5-7 leads to the hydride-azabutadienyl-osmium(IV) complexes [OsH(η⁵-C ₅H₅){NH=C(ρ-C₆H₄R)CH=C-(CH ₃)}(PHⁱPr₂)]BF₄ (R = CH₃ (8), H (9), Cl (10)), as a consequence of the protonation of the metallic center of 5-7. Complexes 3 and 10 have been characterized by X-ray diffraction analysis.

Full text of DOI:10.1021/om049178a

Organometallics 2005, 24, 1225-1232
1225
Formation of Azabutadienyl Fragments by Addition of
the Isopropenyl Substituent of a Phosphine to
Benzonitriles, Promoted by an Osmium Center
Miguel Baya, Miguel A. Esteruelas,* Ana I. Gonza´lez, Ana M. Lo´pez,* and
Enrique On˜ate
Departamento de Quı´mica Inorga´nica, Instituto de Ciencia de Materiales de Arago´n,
Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain
Received October 22, 2004
Complex Os(η5-C5H5)Cl{[η2-CH2dC(CH3)]PiPr2} (1) reacts with p-tolunitrile, benzonitrile,
and p-chlorobenzonitrile to give the corresponding iminophosphine derivatives Os(η5-C5H5)-
Cl{NHdC(p-C6H4R)CHdC(CH3)PiPr2} (R ) CH3 (2), H (3), Cl (4)), as a result of the insertion
of the carbon-nitrogen triple bond of the nitriles into one of the C(sp2)-H bonds of the
phosphine of 1. Treatment of 2-4 with NaBH4 and methanol produces the rupture of the
P-C(CH3) bond of the iminophosphine ligands and the formation of the respective
osmapyrrole derivatives Os(η5-C5H5){NH-C(p-C6H4R)-CH-C(CH3)}(PHiPr2) (R ) CH3 (5),
H (6), Cl (7)). The addition of HBF4‚Et2O to the diethyl ether solutions of 5-7 leads to
the hydride-azabutadienyl-osmium(IV) complexes [OsH(η5-C5H5){NHdC(p-C6H4R)CHdC-
(CH3)}(PHiPr2)]BF4 (R ) CH3 (8), H (9), Cl (10)), as a consequence of the protonation of the
metallic center of 5-7. Complexes 3 and 10 have been characterized by X-ray diffraction
analysis.
Introduction
seems to be the most reasonable first step in order to
perform alkane functionalization.
The formation of carbon-carbon bonds mediated by
transition metal compounds has emerged in its own
right over the past few years as an important step in
organic synthesis.1 Because the alkanes are among the
most abundant molecules, there is great interest in the
development of methods for the coupling between alkyl
groups and other organic fragments.2 However, the
direct addition of a C(sp3)-H bond to unsaturated
molecules remains difficult.
In contrast to alkanes, the reactions involving alkenes
are promising processes regarding synthetic applica-
tions. Thus, for example, those between olefins and
nitriles provide convenient routes to useful organo-
nitrogen molecules.3 So, the alkane dehydrogenation4
In addition, it should be noted that alkanes are very
weak Lewis bases and, therefore, blind molecules. They
generally need the assistance of a coordination auxiliary
to approach the transition metal. In this context,
alkylphosphines could play an important role as guiding
alkane models. The use of a coordination assistance
strategy involves the rupture of the carbon-assistant
bond after the coupling, as an additional step within
the overall synthetic process.5
As a part of our work on the chemistry of the
Os-cyclopentadienyl unit,6 we have recently reported
that the triisopropylphosphine complex Os(η5-C5H5)Cl(Pi-
Pr3)2 can be converted into the isopropenyldi(isopropyl)-
phosphine derivative Os(η5-C5H5)Cl{[η2-CH2dC)CH3)]Pi-
Pr2} in a three-step procedure (Scheme 1). The process
involves the oxidative addition of molecular hydrogen
to Os(η5-C5H5)Cl(PiPr3)2, the subsequent reaction of the
* To whom correspondence should be addressed. E-mail: maester@
posta.unizar.es.
(1) See for example: (a) Engel, P. F.; Pfeffer, M. Chem. Rev. 1995,
95, 2281. (b) Naota, T.; Takaya, H.; Murahashi, S.-I. Chem. Rev. 1998,
98, 2599. (c) Guari, Y.; Sabo-Etienne, S.; Chaudret, B. Eur. J. Inorg.
Chem. 1999, 1047. (d) van Leeuwen, P. W. N. M.; Kamer, P. C. J.;
Reek, J. N. H.; Dierkes, P. Chem. Rev. 2000, 100, 2741. (e) Trost, B.
M.; Toste, F. D.; Pinkerton, A. B. Chem. Rev. 2001, 101, 2067. (f)
Esteruelas, M. A.; Lo´pez, A. M. In Recent Advances in Hydride
Chemistry; Elsevier: Amsterdam, 2001; Chapter 7, pp 189-248. (g)
Guerchais, V. Eur. J. Inorg. Chem. 2002, 783.
(4) See for example: (a) Shilov, A. E.; Shul’pin, G. B. Chem. Rev.
1997, 97, 2879. (b) Edwards, A. J.; Esteruelas, M. A.; Lahoz, F. J.;
Lo´pez, A. M.; On˜ate, E.; Oro, L. A.; Tolosa, J. I. Organometallics 1997,
16, 1316. (c) Barrio, P.; Esteruelas, M. A.; On˜ate, E. Organometallics
2003, 22, 2472 (d) Esteruelas, M. A.; Lledo´s, A.; Maseras, F.; Oliva´n,
M.; On˜ate, E.; Tajada, M. A.; Toma`s, J. Organometallics 2003, 22, 2087.
(e) Esteruelas, M. A.; Lledo´s, A.; Oliva´n, M.; On˜ate, E.; Tajada, M. A.;
Ujaque, G. Organometallics 2003, 22, 3753. (f) Go¨ttker-Schnetmann,
I.; White, P.; Brookhart, M. J. Am. Chem. Soc. 2004, 126, 1804. (g)
Go¨ttker-Schnetmann, I.; White, P. S.; Brookhart, M. Organometallics
2004, 23, 1766. (h) Go¨ttker-Schnetmann, I.; Brookhart, M. J. Am.
Chem. Soc. 2004, 126, 9330.
(2) See for example: (a) Stahl, S. S.; Labinger, J. A.; Bercaw, J. E.
Angew. Chem., Int. Ed. 1998, 37, 2180. (b) Chen, H.; Schlecht, S.;
Semple, T. C.; Hartwig, J. F. Science 2000, 287, 1995. (c) Jones, W. D.
Science 2000, 287, 1942. (d) Kondo, Y.; Garc´ıa-Cuadrado, D.; Hartwig,
J. F.; Boaen, N. K.; Wagner, N. L.; Hillmyer, M. A. J. Am. Chem. Soc.
2002, 124, 1164. (e) Periana, R. A.; Mironov, O.; Taube, D.; Bhalla,
G.; Jones, C. J. Science 2003, 301, 814.
(3) Michelin, R. A.; Mozzon, M.; Bertani, R. Coord. Chem. Rev. 1996,
147, 299.
(5) Crochet, P.; Demerseman, B.; Rocaboy, C.; Schleyer, D. Organo-
metallics 1996, 15, 3048, and references therein.
10.1021/om049178a CCC: $30.25 © 2005 American Chemical Society
Publication on Web 02/09/2005

1226 Organometallics, Vol. 24, No. 6, 2005
Baya et al.
Scheme 1
Figure 1. Molecular diagram of Os(η5-C5H5)Cl{NHd
C(Ph)CHdC(CH3)PiPr2} (3).
resulting dihydride with diphenylacetylene to afford
Os(η5-C5H5)Cl(η2-PhCtCPh)(PiPr3), and the reduction
of the coordinated alkyne by hydrogen transfer from an
isopropyl substituent of the phosphine that is dehydro-
genated.7
Our interest in developing new carbon-carbon cou-
pling processes,1f in particular those leading to organo-
nitrogen fragments,8 prompted us to investigate the
reactions of the isopropenyldi(isopropyl)phosphine com-
CHdC(CH3)PiPr2} (R ) CH3 (2), H (3), Cl (4)), as a
result of the addition of one of the C(sp2)-H bonds of
the isopropenyl substituent of the phosphine of 1 to the
carbon-nitrogen triple bond of the nitriles. The coupling
is regiospecific and involves the formation of new
carbon-carbon and nitrogen-hydrogen bonds (eq 1).
plex Os(η5-C5H5)Cl{[η2-CH2dC)CH3)]PiPr2} with benzo-
nitriles. In this paper, we show the formation of aza-
butadienyl fragments by transfer of the isopropenyl
group of this compound from the phosphine to benzo-
nitriles.
Results and Discussion
Complexes 2-4 were isolated as purple solids in 60-
Addition of the Isopropenyl Group to Nitriles.
65% yield and characterized by MS, elemental analysis,
In toluene under reflux, the isopropenyldi(isopropyl)-
1
IR, and H, 13C{1H}, and 31P{1H} NMR spectroscopy.
phosphine complex Os(η5-C5H5)Cl{[η2-CH2dC)CH3)]Pi-
Pr2} (1) reacts with p-tolunitrile, benzonitrile, and
p-chlorobenzonitrile to give the corresponding imino-
Complex 3 was further characterized by an X-ray
crystallographic study. The structure has two chemically
equivalent but crystallographically independent mol-
ecules in the asymmetric unit. A drawing of one of them
is shown in Figure 1. Selected bond distances and angles
for both molecules are listed in Table 1.
phosphine derivatives Os(η5-C5H5)Cl{NHdC(p-C6H4R)-
(6) (a) Esteruelas, M. A.; Go´mez, A. V.; Lo´pez, A. M.; Oro, L. A.
Organometallics 1996, 15, 878. (b) Esteruelas, M. A.; Lo´pez, A. M.;
Ruiz, N.; Tolosa, J. I. Organometallics 1997, 16, 4657. (c) Crochet, P.;
Esteruelas, M. A.; Gutie´rrez-Puebla, E. Organometallics 1998, 17,
3141. (d) Crochet, P.; Esteruelas, M. A.; Lo´pez, A. M.; Ruiz, N.; Tolosa,
J. I. Organometallics 1998, 17, 3479. (e) Baya, M.; Crochet, P.;
Esteruelas, M. A.; Gutie´rrez-Puebla, E.; Ruiz, N. Organometallics 1999,
18, 5034. (f) Esteruelas, M. A.; Gutie´rrez-Puebla, E.; Lo´pez, A. M.;
On˜ate, E.; Tolosa, J. I. Organometallics 2000, 19, 275. (g) Baya, M.;
Crochet, P.; Esteruelas, M. A.; Gutie´rrez-Puebla, E.; Lo´pez, A. M.;
Modrego, J.; On˜ate, E.; Vela, N. Organometallics 2000, 19, 2585. (h)
Esteruelas, M. A.; Lo´pez, A. M.; Tolosa, J. I.; Vela, N. Organometallics
2000, 19, 4650. (i) Baya, M.; Crochet, P.; Esteruelas, M. A.; On˜ate, E.
Organometallics 2001, 20, 240. (j) Baya, M.; Crochet, P.; Esteruelas,
M. A.; Lo´pez, A. M.; Modrego, J.; On˜ate, E. Organometallics 2001, 20,
4291. (k) Baya, M.; Esteruelas, M. A.; On˜ate, E. Organometallics 2001,
20, 4875. (l) Carbo´, J. J.; Crochet, P.; Esteruelas, M. A.; Jean, Y.; Lledo´s,
A.; Lo´pez, A. M.; On˜ate, E. Organometallics 2002, 21, 305. (m) Baya,
M.; Esteruelas, M. A. Organometallics 2002, 21, 2332. (n) Baya, M.;
Esteruelas, M. A.; On˜ate, E. Organometallics 2002, 21, 5681. (o)
Esteruelas, M. A.; Gonza´lez, A. I.; Lo´pez, A. M.; On˜ate, E. Organo-
metallics 2003, 22, 414. (p) Esteruelas, M. A.; Lo´pez, A. M.; On˜ate, E.;
Royo, E. Organometallics 2004, 23, 3021. (q) Esteruelas, M. A.;
Gonza´lez, A. I.; Lo´pez, A. M.; On˜ate, E. Organometallics 2004, 23, 4858.
(7) Baya, M.; Buil, M. L.; Esteruelas, M. A.; On˜ate, E. Organo-
metallics 2004, 23, 1416.
The molecules are associated by intermolecular Cl‚‚‚‚
H-N hydrogen bonds. Thus, the separations between
the atoms involved in the interactions (2.55(3) and
2.60(3) Å) are significantly shorter than the sum of the
van der Waals radii of hydrogen and chlorine (rvdw(H)
) 1.20, rvdw(Cl) ) 1.80 Å).
The geometry around the osmium atom of each
molecule can be described as a distorted octahedron,
with the cyclopentadienyl ligand occupying the three
sites of a face. The formed P,N-chelate ligand acts with
a bite angle of 90.34(8)° in both molecules and forms
an almost planar six-membered ring with the metal.
The imine group is bonded to the osmium center with
Os-N-C angles of 136.9(2)° (molecule a) and 137.3(2)°
(molecule b), which compare well with the M-N-C
angles found in the osmium derivatives OsCl2(dCd
CHPh)(NHdCH2)(PiPr3)2 (142.5(6)°), [OsCl(dCdCHPh)-
(NHdCMe2)(H2O)(PiPr3)2][CF3SO3] (142.7(6)°),9 and
OsCl2(dCdCHPh)(NHdCMe2)(NH2CH2CHdCH2)-
(8) (a) Esteruelas, M. A.; Go´mez, A. V.; Lo´pez, A. M.; On˜ate, E.; Ruiz,
N. Organometallics 1999, 18, 1606. (b) Buil, M. L.; Esteruelas, M. A.;
Lo´pez, A. M.; On˜ate, E. Organometallics 2003, 22, 162. (c) Buil, M. L.;
Esteruelas, M. A.; Lo´pez, A. M.; On˜ate, E. Organometallics 2003, 22,
5274.
(9) Castarlenas, R.; Esteruelas, M. A.; On˜ate, E. Organometallics
2000, 19, 5454.

Formation of Azabutadienyl Fragments
Table 1. Selected Bond Distances (Å) and Angles (deg) for Complex
Os(η5-C5H5)Cl{NHdC(Ph)CHdC(CH3)PiPr2} (3)
Organometallics, Vol. 24, No. 6, 2005 1227
molecule a
molecule b
molecule a
molecule b
Os(1)-Cl(1)
2.4468(8)
2.2686(9)
2.015(3)
2.174(3)
2.187(3)
2.235(3)
2.207(3)
1.864(3)
94.42(3)
86.29(8)
120.1
2.4461(8)
2.2687(9)
2.017(3)
2.176(3)
2.181(3)
2.222(3)
2.202(3)
1.867(3)
94.19(3)
86.54(8)
120.1
Os(1)-C(21)
P(1)-C(9)
2.208(3)
1.818(3)
1.307(4)
1.485(4)
1.457(5)
1.336(5)
1.512(5)
1.846(3)
115.23(12)
136.9(2)
121.5(3)
120.4(3)
119.6(3)
124.1(3)
116.2(3)
2.201(3)
1.817(3)
1.304(4)
1.487(4)
1.459(5)
1.344(5)
1.519(5)
1.858(3)
114.99(12)
137.3(2)
121.9(3)
120.2(3)
119.9(3)
124.0(3)
116.1(3)
Os(1)-P(1)
Os(1)-N(1)
N(1)-C(1)
Os(1)-C(17)
C(1)-C(2)
Os(1)-C(18)
C(1)-C(8)
Os(1)-C(19)
C(8)-C(9)
Os(1)-C(20)
C(9)-C(10)
P(1)-C(11)
P(1)-C(14)
Cl(1)-Os(1)-P(1)
Cl(1)-Os(1)-N(1)
Cl(1)-Os(1)-Ma
P(1)-Os(1)-N(1)
P(1)-Os(1)-Ma
N(1)-Os(1)-Ma
C(8)-C(9)-C(10)
Os(1)-P(1)-C(9)
Os(1)-N(1)-C(1)
P(1)-C(9)-C(8)
P(1)-C(9)-C(10)
N(1)-C(1)-C(2)
N(1)-C(1)-C(8)
C(2)-C(1)-C(8)
90.34(8)
128.1
126.3
118.1(3)
90.34(8)
128.2
126.3
117.9(3)
a M is the centroid of the C(17)-C(21) Cp ligand.
Scheme 2
(PiPr3) (141.8(6)°)10 and in the rhenium complex Re(η5-
C5H5)(NO)(NHdCPh2)(PPh3) (136.2(2)°).11 The Os(1)-
N(1) bond lengths (2.015(3) (a) and 2.017(3) (b) Å) agree
well with those found in the above-mentioned imine-
osmium derivatives and support the Os-N single bond
formulation. The N(1)-C(1) distances (1.307(4) (a) and
1.304(4) (b) Å) are also similar to the observed ones in
imine derivatives,9-11 azavinylidene compounds,12 or-
ganic azaallenium cations,13 and 2-azaallenyl com-
plexes.14 The C(1)-C(8) (1.457(5) (a) and 1.459(5) (b)
Å) and C(8)-C(9) (1.336(5) (a) and 1.344 (b) Å) bond
lengths are in accordance with the mean values reported
for single and double C(sp2)-C(sp2) bonds, 1.48 and 1.34
Å, respectively.15 The P(1)-C(9) distances (1.818(3) (a)
and 1.817(3) (b) Å) are between 0.03 and 0.05 Å shorter
than the P(1)-C(11) (1.864(3) (a) and 1.867(3) (b) Å)
and P(1)-C(14) (1.846(3) (a) and 1.858(3) (b) Å) bond
lengths. A similar fact has been observed for the
the complex OsH(η5-C5H4CH3){η2-(E)-PhCHdCHPh}-
{P[C(CH3)dCH2]iPr2} (2.2886(11) Å).7 Since in the latter
the phosphorus atom is also bonded to a C(sp2) sub-
stituent and two C(sp3) groups, this difference appears
to be a consequence of the chelate effect in 3.
isopropenyldi(isopropyl)phosphine complex [Os(η5-
C5H5){η2-(Z)-PhCHdCHPh}{[η2-CH2dC(CH3)]PiPr2}]-
PF6, where the P-C(sp2) distance is about 0.06 Å
shorter than the P-C(sp3) bond lengths. The Os(1)-
P(1) distances of 2.2686(9) (a) and 2.2687(9) (b) Å are
about 0.02 Å shorter than the Os-P distance found in
In agreement with the presence of the N-H group in
2-4, the IR spectra in Nujol of these compounds show
a ν(N-H) band between 3150 and 3190 cm-1. In the 1H
NMR spectra in benzene-d6 at room temperature, the
NH resonance appears at about 11.9 ppm, as a broad
signal. In addition, the resonances corresponding to the
olefinic CH-hydrogen atom and the PCCH3 protons of
the P,N-chelate ligands should be mentioned. The
olefinic hydrogen atom of these ligands gives rise to a
double multiplet at 6.5 ppm, with a H-P coupling
constant of about 27 Hz, whereas the PCCH3 protons
display a double doublet at about 1.4 ppm, with H-P
and H-H coupling constants of about 7 and 1 Hz,
respectively. In the 13C{1H} NMR spectra the C(sp2)
carbon atoms of the diheterometallaring give rise to
doublets at about 160 (CN), 140 (CH), and 132 (CP)
ppm, with C-P coupling constants of between 10 and
11, about 8, and between 20 and 22 Hz, respectively.
The 31P{1H} NMR spectra contain a singlet at about 24
ppm, shifted about 27 ppm to lower field with regard to
that of 1.
(10) Castarlenas, R.; Esteruelas, M. A.; Gutie´rrez-Puebla, E.; On˜ate,
E. Organometallics 2001, 20, 1545.
(11) Knight, D. A.; Dewey, M. A.; Stark, G. A.; Bennett, B. K.; Arif,
A. M.; Gladysz, J. A. Organometallics 1993, 12, 4523.
(12) (a) Esteruelas, M. A.; Lahoz, F. J.; Oliva´n, M.; On˜ate, E.; Oro,
L. A. Organometallics 1994, 13, 3315. (b) Werner, H.; Daniel, T.;
Mu¨ller, M.; Mahr, N. J. Organomet. Chem. 1996, 512, 197. (c) Brown,
S. N. Inorg. Chem. 2000, 39, 378. (d) Castarlenas, R.; Esteruelas, M.
A.; Gutie´rrez-Puebla, E.; Jean, Y.; Lledo´s, A.; Mart´ın, M.; On˜ate, E.;
Toma`s, J. Organometallics 2000, 19, 3100. (e) Castarlenas, R.; Es-
teruelas, M. A.; On˜ate, E. Organometallics 2001, 20, 3283.
(13) (a) Jochims, J. C.; Abu-El-Halawa, R.; Jibril, I.; Huttner, G.
Chem. Ber. 1984, 117, 1900. (b) Al-Talib, M.; Jochims, J. C. Chem.
Ber. 1984, 117, 3222. (c) Al-Talib, M.; Jibril, I.; Wu¨rthwein, E.-U.;
Jochims, J. C.; Huttner, G. Chem. Ber. 1984, 117, 3365. (d) Kupfer,
R.; Wu¨rthwein, E.-U.; Nagel, M.; Allmann, R. Chem. Ber. 1985, 118,
643. (e) Al-Talib, M.; Jibril, I.; Huttner, G.; Jochims, J. C. Chem. Ber.
1985, 118, 1876. (f) Al-Talib, M.; Jochims, J. C.; Zsolnai, L.; Huttner,
G. Chem. Ber. 1985, 118, 1887. (g) Wu¨rthwein, E.-U.; Kupfer, R.;
Allmann, R.; Nagel, M. Chem. Ber. 1985, 118, 3632. (h) Krestel, M.;
Kupfer, R.; Allmann, R.; Wu¨rthwein, E.-U. Chem. Ber. 1987, 120, 1271.
(14) (a) Seitz, F.; Fischer, H.; Riede, J. J. Organomet. Chem. 1985,
287, 87. (b) Aumann, R.; Althaus, S.; Kru¨ger, C.; Betz, P. Chem. Ber.
1989, 122, 357. (c) Esteruelas, M. A.; Go´mez, A. V.; Lahoz, F. J.; Lo´pez,
A. M.; On˜ate, E.; Oro, L. A. Organometallics 1996, 15, 3423.
(15) Orpen, A. G.; Brammer, L.; Allen, F. H.; Kennard, O.; Watson,
D. G.; Taylor, R. J. Chem. Soc., Dalton Trans. 1989, S1.
The formation of 2-4 can be rationalized according
to Scheme 2. Initially, the activation of one of the
C(sp2)-H bonds of the CH2 group of the isopropenyl
substituent of the phosphine of 1 should afford a

1228 Organometallics, Vol. 24, No. 6, 2005
Baya et al.
Scheme 3
hydride-alkenyl intermediate. Thus, the insertion of the
carbon-nitrogen triple bond of the nitriles into the Os-
C(sp2) bond, followed by the subsequent migration of
the hydride from the metallic center to the nitrogen
atom, could give the iminophosphine derivatives. Al-
though the insertion of the carbon-nitrogen triple bond
of nitriles into a metal-carbon σ bond is not a common
process, it has been found to occur.16
pyrrole units also appears as a singlet, between 126 and
129 ppm. The OsC and CN resonances are observed as
doublets, between 222 and 224 ppm and between 177
and 180 ppm, with C-P coupling constants of about 7
and 4 Hz, respectively. The 31P{1H} NMR spectra show
a singlet at about 41 ppm.
The 13C{1H} NMR spectra of 5-7 are consistent with
the delocalized structure shown in eq 2 and suggest that
for an adequate description of the bonding situation in
the five-membered heterometallaring of these com-
pounds the resonance forms shown in Scheme 3 should
be taken into account. Thus, the OsC resonance in 5-7
appears shifted about 70 ppm to higher field in com-
parison with the shift of a typical Os-carbene17 and more
than 30 ppm to lower field with regard to the chemical
shift observed for the OsCR resonance in six-coordinate
osmium-alkenyl complexes.18 The chemical shifts of
the OsC resonance of 5-7 are consistent with
those corresponding to the OsC resonance of complexes
2. Release of the Isopropenyl-Benzonitrile Units
from the iPr2P Group. The fragments resulting of the
addition of the C(sp2)-H bond of the isopropenyl sub-
stituent of the phosphine to the carbon-nitrogen triple
bond of the nitriles can be removed from the phosphine
group by reaction with sodium tetrahydrideborate (eq
2). Treatment at room temperature of toluene solutions
of 2-4 with approximately 8.0 equiv of sodium tetra-
hydrideborate and 1.0 mL of methanol produces the
cleavage of the P-C(CH3) bond of the iminophos-
phine ligands and the formation of the corresponding
osmapyrrole
derivatives
Os(η5-C5H5){NH-C(p-
C6H4R)-CH-C(CH3)}(PHiPr2) (R ) CH3 (5), H (6), Cl
(7)).
Os{CHCHC(O)Ph}Cl(CO)(PiPr3)2 (230.13 ppm),19 OsH-
{CHCHC(O)CH3}(CO)(PiPr3)2 (250.8 ppm),20 and OsH3-
{C6H8C(O)CH3}(PiPr3)2 (255.9 ppm),21 where a similar
bonding situation has been proposed to exist. On the
basis of spectroscopic data, delocalized metalapyrrole
structures have been also proposed for W,22 Fe,23 and
Ir24 complexes.
The formation of 5-7 by reaction of 2-4 with sodium
tetrahydrideborate and methanol can be rational-
ized according to Scheme 4. The replacement of
chloride by hydride in the starting compounds
should afford hydride-iminophosphine derivatives, which
should evolve by elimination of [NHdC(p-C6H4R)CHd
C(CH3)PHiPr2]+.25 These cations could stabilize the
metallic center by means of the coordination of the
nitrogen atom and the carbon-carbon double bond.
Complexes 5-7 were isolated as brown oils in high
yield (70-90%) and characterized by MS and 1H,
13C{1H}, and 31P{1H} NMR spectroscopy. In agreement
with the presence of a diisopropylphosphine ligand in
these compounds, their 1H NMR spectra in benzene-d6
at room temperature contain a HP resonance at about
3.5 ppm, which appears as a double triplet with H-P
and H-H coupling constants of about 336 and 4 Hz,
1
respectively. The H NMR spectra are also consistent
with the cleavage of the P-C(CH3) bond and the
formation of osmapyrrole units. Thus, the CH resonance
of the five-membered heterometallacycles does not show
any H-P coupling and appears as a singlet at about
7.5 ppm. The NH resonance is observed at about 8.8
ppm, shifted about 3 ppm toward higher field with
regard to the chemical shifts observed for 2-4. In the
13C{1H} NMR spectra the CH resonance of the osma-
(17) Esteruelas, M. A.; Lahoz, F. J.; On˜ate, E.; Oro, L. A.; Valero,
C.; Zeier, B. J. Am. Chem. Soc. 1995, 117, 7935.
(18) (a) Werner, H.; Esteruelas, M. A.; Otto, H. Organometallics
1986, 5, 2295. (b) Albe´niz, M. J.; Esteruelas, M. A.; Lledo´s, A.; Maseras,
F.; On˜ate, E.; Oro, L. A.; Sola, E.; Zeier, B. J. Chem. Soc., Dalton Trans.
1997, 181.
(19) Esteruelas, M. A.; Lahoz, F. J.; On˜ate, E.; Oro, L. A.; Zeier, B.
Organometallics 1994, 13, 1662.
(16) See for example: (a) Simpson, S. J.; Andersen, R. A. J. Am.
Chem. Soc. 1981, 103, 4063. (b) Bercaw, J. E.; Davies, D. L.; Wolc-
zanski, P. T. Organometallics 1986, 5, 443. (c) Bochmann, M.; Wilson,
L. M. J. Chem. Soc., Chem. Commun. 1986, 1610. (d) Dormond, A.;
Aaliti, A.; Elbouadili, A.; Moise, C. J. Organomet. Chem. 1987, 329,
187. (e) Sternal, R. S.; Sabat, M.; Marks, T. J. J. Am. Chem. Soc. 1987,
109, 7920. (f) den Haan, K. H.; Luinstra, G. A.; Meetsma, A.; Teuben,
J. H. Organometallics 1987, 6, 1509. (g) Jordan, R. F.; Bajgur, C. S.;
Dasher, W. E.; Rheingold, A. L. Organometallics 1987, 6, 1041. (h)
Richeson, D. S.; Mitchell, J. F.; Theopold, K. H. J. Am. Chem. Soc.
1987, 109, 5868. (i) Bochmann, M.; Wilson, L. M.; Husthouse, M. B.;
Motevalli, M. Organometallics 1988, 7, 1148. (j) Jordan, R. F.;
LaPointe, R. E.; Bradley, P. K.; Baenziger, N. Organometallics 1989,
8, 2892. (k) Stack, J. G.; Doney, J. J.; Bergman, R. G.; Heathcock, C.
H. Organometallics 1990, 9, 453. (l) Alelyunas, Y. W.; Jordan, R. F.;
Echols, S. F.; Borkowsky, S. L.; Bradley, P. K. Organometallics 1991,
10, 1406. (m) Klose, A.; Solari, E.; Ferguson, R.; Floriani, C.; Chiesi-
Villa, A.; Rizzoli, C. Organometallics 1993, 12, 2414.
(20) Edwards, A. J.; Elipe, S.; Esteruelas, M. A.; Lahoz, F. J.; Oro,
L. A.; Valero, C. Organometallics 1997, 16, 3828.
(21) Barrio, P.; Castarlenas, R.; Esteruelas, M. A.; On˜ate, E.
Organometallics 2001, 20, 2635.
(22) (a) Legzdins, P.; Lumb, S. A. Organometallics 1997, 16, 1825.
(b) Legzdins, P.; Lumb. S. A.; Young, V. G., Jr. Organometallics 1998,
17, 854.
(23) Busetto, L.; Camiletti, C.; Zanotti, V.; Albano, V. G.; Sabatino,
P. J. Organomet. Chem. 2000, 593-594, 335.
(24) (a) Alvarado, Y.; Daff, P. J.; Pe´rez, P.; Poveda, M. L.; Sa´nchez-
Delgado, R.; Carmona, E. Organometallics 1996, 15, 2192. (b) Al´ıas,
F. M.; Poveda, M. L.; Sellin, M.; Carmona, E.; Gutie´rrez-Puebla, E.;
Monge, A. Organometallics 1998, 17, 4124. (c) Al´ıas, F. M.; Daff, P. J.;
Paneque, M.; Poveda, M. L.; Carmona, E.; Pe´rez, P. J.; Salazar, V.;
Alvarado, Y.; Atencio, R.; Sa´nchez-Delgado, R. Chem. Eur. J. 2002, 8,
5132.
(25) Esteruelas, M. A.; Lahoz, F. J.; Mart´ın, M.; On˜ate, E.; Oro, L.
A. Organometallics 1997, 16, 4572.

Formation of Azabutadienyl Fragments
Organometallics, Vol. 24, No. 6, 2005 1229
Scheme 4
Figure 2. Molecular diagram of the cation of [OsH(η5-
C5H5){NHdC(p-C6H4Cl))CHdC(CH3)}(PHiPr2)]BF4 (10).
Transition metal complexes containing an η2-[R3PC(R)d
CR′2]+ ligand are known.26 Finally, the activation of the
P-C(CH3) bond of these cations should give 5-7.
3. Protonation of the Osmapyrrole Units. Com-
plexes 5-7 react with HBF4‚Et2O. The addition at 0 °C
of 1.0 equiv of the acid to diethyl ether solutions of these
compounds leads to the corresponding hydride-aza-
Table 2. Selected Bond Distances (Å) and Angles
(deg) for the Complex [OsH(η5-C5H5)-
{NHdC(p-C6H4Cl))CHdC(CH3)}(PHiPr2)]BF4 (10)
Os(1)-P(1)
Os(1)-N(1)
Os(1)-C(3)
Os(1)-C(17)
Os(1)-C(18)
Os(1)-C(19)
Os(1)-C(20)
Os(1)-C(21)
2.290(2)
2.040(5)
2.098(7)
2.202(6)
2.188(8)
2.264(8)
2.274(6)
2.244(7)
P(1)-C(11)
P(1)-C(14)
P(1)-H(1B)
N(1)-C(1)
C(1)-C(2)
C(1)-C(5)
C(2)-C(3)
C(3)-C(4)
1.802(8)
1.862(8)
1.480(6)
1.314(9)
1.419(10)
1.467(10)
1.366(10)
1.509(9)
butadienyl-osmium(IV) derivatives [OsH(η5-C5H5){NHd
C(p-C6H4R)CHdC(CH3)}(PHiPr2)]BF4 (R ) CH3 (8), H
(9), Cl (10)), as a result of the addition of the proton of
the acid to the metallic center of 5-7. Complexes 8-10
were isolated as yellow solids in high yield (80-82%),
according to eq 3.
Ma-Os(1)-H(01)
Ma-Os(1)-N(1)
Ma-Os(1)-C(3)
Ma-Os(1)-P(1)
N(1)-Os(1)-C(3)
N(1)-Os(1)-P(1)
P(1)-Os(1)-C(3)
N(1)-Os(1)-H(01)
P(1)-Os(1)-H(01)
103.5
129.0
117.9
130.1
75.4(3)
C(3)-Os(1)-H(01) 139.0(2)
Os(1)-N(1)-C(1)
N(1)-C(1)-C(2)
N(1)-C(1)-C(5)
C(2)-C(1)-C(5)
120.3(5)
113.8(6)
121.8(6)
124.4(7)
115.2(7)
115.3(5)
121.5(7)
123.1(5)
99.89(18) C(1)-C(2)-C(3)
79.6(2)
79.0(2)
74.0(2)
C(2)-C(3)-Os(1)
C(2)-C(3)-C(4)
C(4)-C(3)-Os(1)
a M represents the midpoint of the Cp ring.
N(1)-C(1) angle of 120.3(5)°. The Os(1)-N(1) (2.040(5)
Å), N(1)-C(1) (1.314(9) Å), C(1)-C(2) (1.419(10) Å), and
C(2)-C(3) (1.366(10) Å) bond lengths are statistically
identical with the distances Os(1)-N(1), N(1)-C(1),
C(1)-C(8), and C(8)-C(9) of 3. This indicates that the
bonding situation in the sequence Os-N-C-C-C of the
heterometallacycle of 10 is the same as that in the
diheterometallacycle of 3. Furthermore, it suggests that
the contribution of the carbene resonance form to the
structure of the five-membered rings of 8-10 is not
significant. In agreement with this, the Os-C(3)
distance of 2.098(7) Å is similar to those found in
alkenyl derivatives such as [Os{(E)-CHdCHPh}(Ct
Complexes 8-10 were characterized by MS, elemen-
1
tal analysis, IR, and H, 13C{1H}, and 31P{1H} NMR
spectroscopy. Complex 10 was further characterized by
an X-ray crystallographic study.27 Figure 2 shows a view
of the structure. Table 2 collects selected bond distances
and angles.
The distribution of ligands around the osmium atom
can be described as a four-legged piano-stool geometry
with the metalated carbon atom (C(3)) of the azabuta-
dienyl fragment transoid to the hydride and cisoid to
the phosphine ligand. The C(3)-Os(1)-H(01) and P(1)-
Os(1)-C(3) angles are 139.0(2)° and 79.6(2)°, respec-
tively.
The chelate azabutadienyl ligand acts with a bite
angle of 75.4(3)°. The five-membered heterometallacycle
is almost planar. The deviations (in Å) from the best
plane are 0.004(3) (Os(1)), -0.006(4) (N(1)), 0.004(5)
(C(1)), 0.001(5) (C(2)), and -0.004(4) (C(3)). The imine
group is bonded to the metallic center with an Os(1)-
CPh)(tCCH2Ph)(PiPr3)2]BF4 (2.036(9) Å),28 OsH(η5-
{C5H4SiPh3){o-C6H4C(CH3)dCH}(PiPr3) (2.082(5) Å),6k
or [Os{CHdCHC(O)OCH3}(dCdCHCO2CH3)(CO)(Pi-
Pr3)2]BF4 (2.078(5) Å).29
The 13C{1H} NMR spectra of 8-10 agree well with
the structural parameters of the heterometallacycle of
(26) See for example: Esteruelas, M. A.; Lahoz, F. J.; Mart´ın, M.;
Mart´ınez, A.; Oro, L. A.; Puerta, M. C.; Valerga, P. J. Organomet.
Chem. 1999, 577, 265.
(27) The structure has two chemically equivalent but crystallo-
graphically independent molecules in the asymmetric unit. However,
we only discuss one of them because the other one is disordered.
(28) Barrio, P.; Esteruelas, M. A.; On˜ate, E. J. Am. Chem. Soc. 2004,
126, 1946.
(29) Bohanna, C.; Buil, M. L.; Esteruelas, M. A.; On˜ate, E.; Valero,
C. Organometallics 1999, 18, 5176.

1230 Organometallics, Vol. 24, No. 6, 2005
Baya et al.
10 and reveal that the contribution of the carbene
resonance form to the structure of the five-membered
heterometallarings is much less in 8-10 than in 5-7.
Thus, in the 13C{1H} NMR spectra of 8-10, the OsC
resonance appears as a doublet, between 194 and 197
ppm, shifted almost 30 ppm toward higher field with
regard to the chemical shifts observed for 5-7. The C-P
coupling constant (16 Hz for the three compounds) is
also sensitive to the protonation of the metallic center,
increasing its value more than 100%. The diminution
of the contribution of the carbene resonance form to the
bonding, as a result of the protonation, is in agreement
with the formal oxidation of the metallic center, which
decreases the back-bonding Os(dπ) f C(pπ) interaction.
The CN resonance is observed between 183 and 185
ppm, as a singlet, whereas the CH resonance of the five-
membered rings appears at about 135 ppm as a doublet,
with a C-P coupling constant of 3 Hz for the three
complexes.
leads to the hydride-azabutadienyl-osmium(IV) cations
[OsH(η5-C5H5){NHdC(p-C6H4R)CHdC(CH3)}(PHi-
Pr2)]+.
Although further work needs to be done in order to
develop the methodology, in the light of these results it
is clear that alkylphosphines, after being dehydro-
genated, can be successfully used to add hydrocarbon
fragments to unsaturated organic molecules.
Experimental Section
All reactions were carried out with rigorous exclusion of air
using Schlenk-tube techniques. Solvents were dried by the
usual procedures and distilled under argon prior to use.
1H, 31P{1H}, and 13C{1H} NMR spectra were recorded on
either a Varian UNITY 300, a Varian Gemini 2000, a Bruker
AXR 300, or a Bruker Avance 400 MHz instrument. Chemical
shifts (expressed in parts per million) are referenced to
residual solvent peaks (1H, 13C{1H}) or external H3PO4 (31P{1H}).
Coupling constants, J, are given in hertz. Infrared spectra were
run on a Perkin-Elmer 1730 spectrometer (Nujol mulls on
polyethylene sheets). C, H, and N analyses were carried out
in a Perkin-Elmer 2400 CHNS/O analyzer. Mass spectra
analyses were performed with a VG Austospec instrument. In
LSIMS+ mode, ions were produced with the standard Cs+ gun
at ca. 30 kV, and 3-nitrobenzyl alcohol (NBA) was used in the
matrix.
The 31P{1H} NMR spectra of these compounds are
also sensitive to the formal oxidation of the metallic
center. They show a singlet between 19 and 22 ppm,
shifted about 20 ppm to higher field compared with the
observed one in the spectra of 5-7.
The IR spectra of 8-10 in Nujol are consistent with
the presence of the hydride and azabutadienyl ligands
in these compounds. Thus, the most noticeable feature
of the spectra is the presence of ν(N-H) and ν(Os-H)
bands, between 3330 and 3345 cm-1 and between 2050
and 2065 cm-1, respectively. In the 1H NMR spectra in
dichloromethane-d2 at room temperature, the NH reso-
nance is observed between 10.50 and 10.90 ppm, as a
broad signal, whereas the CH resonance of the hetero-
metallarings appears at about 7.3 ppm as a singlet. The
PH hydrogen atom of the diisopropylphosphine ligand
gives rise to a doublet at about 4.5 ppm, with a H-P
coupling constant of about 370 Hz. In the high-field
region of the spectra the hydride resonance is observed
at about -12.4 ppm, as a double doublet by spin
coupling with the phosphorus nucleus of the phosphine
(about 44 Hz) and the NH hydrogen atom (about 4 Hz).
Preparation of Os(η5-C5H5)Cl{NHdC(p-C6H4CH3)CHd
C(CH3)PiPr2} (2). A yellow solution of 1 (160 mg, 0.36 mmol)
in 8 mL of toluene was treated with p-tolunitrile (123 mg, 1.05
mmol) and heated under reflux for 30 h. The resultant deep
purple solution was concentrated to dryness, and the product
was extracted with diethyl ether (5 × 10 mL). The violet
solution was concentrated to dryness, and a purple solid was
obtained. The solid was washed with pentane (4 × 3 mL),
separated by decantation, and dried in vacuo. Yield: 160 mg
(61%). Anal. Calcd for C22H31ClNOsP: C, 46.67; H, 5.52; N,
2.47. Found: C, 46.48; H, 5.32; N, 2.40. IR (Nujol, cm-1): ν(NH)
1
3180 (w). H NMR (300 MHz, C6D6, 293 K): δ 11.90 (br, 1H,
NH), 7.18 (d, JH-H ) 8.1, 2H, o-Ph), 6.85 (d, JH-H ) 8.1, 2H,
m-Ph), 6.64 (dm, JH-P ) 27.3, 1H, dCH-), 4.69 (s, 5H, C5H5),
2.60 (m, 1H, PCH), 1.95 (s, 3H, p-CH3), 1.61 (dd, JH-P ) 14.4,
JH-H ) 6.9, 3H, PCHCH3), 1.58 (m, 1H, PCH), 1.45 (dd, JH-P
) 6.9, JH-H ) 1.0, 3H, PC(CH3)d), 1.07 (dd, JH-P ) 16.2, JH-H
) 7.2, 3H, PCHCH3), 0.85 (dd, JH-P ) 13.2, JH-H ) 7.2, 3H,
PCHCH3), 0.81 (dd, JH-P ) 13.5, JH-H ) 7.2, 3H, PCHCH3).
31P{1H} NMR (121.42 MHz, C6D6, 293 K): δ 24.5 (s). 13C{1H}
1
The last coupling was confirmed by the H-1H COSY
NMR spectra.
NMR (75.42 MHz, C6D6, 293 K, plus APT): δ 160.8 (d, JC-P
)
Concluding Remarks
11, CdNH), 141.6 (s, CipsoPh), 140.6 (d, JC-P ) 8, dCH), 138.2
(s, CipsoPh), 132.6 (d, JC-P ) 21, PC)), 129.8 and 124.6 (both
s, Ph), 74.2 (s, Cp), 35.0 (d, JC-P ) 31, PCH), 27.6 (d, JC-P
33, PCH), 24.7 (s, p-CH3), 21.3 (s, PCHCH3), 21.1 (s, PC(CH3)d
), 19.3 (d, JC-P ) 6, PCHCH3), 18.9 and 18.6 (both s, PCHCH3).
MS (LSIMS+): m/z 567 (M+); 532 (M+ - Cl).
This paper shows the formation of azabutadienyl
fragments, on the coordination sphere of a transition
metal, starting from the isopropenyl substituent of a
phosphine and benzonitriles.
)
The insertion of the carbon-nitrogen triple bond of
Preparation of Os(η5-C5H5)Cl{NHdC(Ph)CHdC(CH3)P-
iPr2} (3). A yellow solution of 1 (152 mg, 0.34 mmol) in 12 mL
of toluene was treated with benzonitrile (0.13 mL, 1.27 mmol)
and heated under reflux for 22 h. The solvent was removed,
and the product was extracted with diethyl ether (25 mL). The
resultant purple solution was concentrated to dryness, and the
purple solid obtained was washed with pentane (4 × 3 mL).
The solid was dried in vacuo. Yield: 121 mg (65%). Anal. Calcd
for C21H29ClNOsP: C, 45.68; H, 5.29; N, 2.54. Found: C, 45.58;
benzonitriles into one of the C(sp2)-H bonds of the
isopropenyl group of the phosphine of Os(η5-C5H5)Cl-
{[η2-CH2dC(CH3)]PiPr2} affords iminophosphine com-
pounds, Os(η5-C5H5)Cl{NHdC(p-C6H4R)CHdC(CH3)P-
iPr2}. Treatment of the latters with sodium tetrahydride-
borate and methanol produces the rupture of the P-C
bond of the iminophosphine ligands and the formation
1
H, 5.25; N, 2.60. IR (Nujol, cm-1): ν(NH) 3152 (w). H NMR
(300 MHz, C6D6, 293 K): δ 11.98 (br, 1H, NH), 7.30-6.90 (m,
5H, Ph), 6.57 (dm, JH-P ) 27.0, 1H, dCH), 4.70 (s, 5H, C5H5),
2.59 (m, 1H, PCH), 1.61 (dd, JH-P ) 14.7, JH-H ) 7.2, 3H,
of Os(η5-C5H5){NH-C(p-C6H4R)-CH-C(CH3)}(PH-
iPr2), containing an osmapyrrole unit. The protonation
of the metallic center of the osmapyrrole complexes
PCHCH3), 1.57 (m, 1H, PCH), 1.43 (dd, JH-P ) 7.2, JH-H
)

Formation of Azabutadienyl Fragments
Organometallics, Vol. 24, No. 6, 2005 1231
1.5, 3H, PC(CH3)d), 1.06 (dd, JH-P ) 16.5, JH-H ) 7.2, 3H,
PCHCH3), 0.83 (dd, JH-P ) 15.3, JH-H ) 7.2, 3H, PCHCH3),
0.81 (dd, JH-P ) 15.3, JH-H ) 7.2, 3H, PCHCH3). 31P{1H} NMR
(121.42 MHz, C6D6, 293 K): δ 24.1 (s). 13C{1H} NMR (75.42
MHz, C6D6, 293 K, plus APT): δ 160.9 (d, JC-P ) 10, CdNH),
293 K): δ 8.79 (br, 1H, NH), 7.55-6.98 (m, 6H, Ph + OsC-
(CH3)CH), 4.70 (s, 5H, C5H5), 3.58 (dt, JH-P ) 336.6, JH-H
)
3.6, 1H, PH), 3.37 (s, 3H, OsC(CH3)), 1.77 (m, 2H, PCH), 0.93-
0.81 (12H, PCHCH3). 31P{1H} NMR (121.42 MHz, C6D6, 293
K): δ 41.4 (s). 13C{1H} NMR (75.42 MHz, C6D6, 293 K, plus
APT, plus HSQC): δ 223.5 (d, JC-P ) 7, OsC), 179.2 (d, JC-P
) 4, CNH), 138.3 (s, CipsoPh), 129.1, 128.6, 126.9, and 126.8
(all s, Ph + OsC(CH3)CH), 72.5 (s, Cp), 39.2 (s, OsC(CH3)),
26.7 (d, JC-P ) 26, PCH), 26.3 (d, JC-P ) 23, PCH), 21.9, 21.3,
and 21.1 (all s, PCHCH3), 20.7 (d, JC-P ) 3, PCHCH3). MS
(LSIMS+): m/z 518 (M+ - H); 400 (M+ - PHiPr2).
144.5 (s, CipsoPh), 140.6 (d, JC-P ) 8, dCH), 132.0 (d, JC-P
)
20, PCd), 129.2, 128.8, and 124.5 (all s, Ph), 74.5 (s, Cp), 35.0
(d, JC-P ) 31, PCH), 27.6 (d, JC-P ) 33, PCH), 24.7, 21.0, 19.3,
18.9, and 18.6 (all s, PCHCH3). MS (LSIMS+): m/z 553 (M+);
518 (M+ - Cl).
Preparation of Os(η5-C5H5)Cl{NHdC(p-C6H4Cl)CHd
Preparation of Os(η5-C5H5){NH-C(p-C6H4Cl)-CH-C-
(CH3)}(PHiPr2) (7). The same procedure described for 5 was
followed, starting from 4 (150 mg, 0.26 mmol) and sodium
tetrahydrideborate (77 mg, 2.04 mmol). The product was
C(CH3)PiPr2} (4). A yellow solution of 1 (150 mg, 0.33 mmol)
in 8 mL of toluene was treated with 4-chlorobenzonitrile (184
mg, 1.34 mmol) and heated under reflux for 15 h. After that
period of time, the solution was cooled to room temperature
and the solvent was removed. The product was extracted with
diethyl ether (4 × 15 mL). The resultant purple solution was
concentrated to dryness, and the purple solid obtained was
washed with pentane (5 × 3 mL), separated by decantation,
and dried in vacuo. Yield: 117 mg (60%). Anal. Calcd for
C21H28Cl2NOsP: C, 43.00; H, 4.81; N, 2.39. Found: C, 43.29;
1
isolated as a brown oil.30 Yield: 115 mg (81%). H NMR (300
MHz, C6D6, 293 K, plus COSY): δ 8.66 (br, 1H, NH), 7.37 (s,
1H, OsC(CH3)CH), 7.22 (d, JH-H ) 8.1, 2H, o-Ph), 7.04 (d, JH-H
) 8.1, 2H, m-Ph), 4.70 (s, 5H, C5H5), 3.47 (dt, JH-P ) 336.9,
JH-H ) 3.6, 1H, PH), 3.34 (s, 3H, OsC(CH3)), 1.75 (m, 2H,
PCH), 0.92-0.78 (12H, PCHCH3). 31P{1H} NMR (121.42 MHz,
C6D6, 293 K): δ 41.0 (s). 13C{1H} NMR (75.42 MHz, C6D6, 293
K, plus APT, plus HMQC, plus HMBC): δ 223.7 (d, JC-P ) 7,
OsC), 177.0 (d, JC-P ) 4, CNH), 136.1 (d, JC-P ) 3, CipsoPh),
133.9 (s, CipsoPh), 128.9, and 127.7 (both s, Ph), 126.2 (s, OsC-
(CH3)CH), 72.3 (s, Cp), 38.8 (s, OsC(CH3)), 26.4 (d, JC-P ) 30,
PCH), 25.9 (d, JC-P ) 27, PCH), 21.5, 20.9, and 20.7 (all s,
PCHCH3), 20.3 (d, JC-P ) 3, PCHCH3). MS (LSIMS+): m/z 552
(M+ - H); 434 (M+ - PHiPr2).
1
H, 4.88; N, 2.60. IR (Nujol, cm-1): ν(NH) 3191 (w). H NMR
(300 MHz, C6D6, 293 K): δ 11.88 (br, 1H, NH), 6.97-6.88 (m,
4H, Ph), 6.40 (dm, JH-P ) 27.0, 1H, dCH), 4.72 (s, 5H, C5H5),
2.59 (m, 1H, PCH), 1.59 (dd, JH-P ) 14.7, JH-H ) 7.2, 3H,
PCHCH3), 1.54 (m, 1H, PCH), 1.39 (dd, JH-P ) 6.9, JH-H
)
1.5, 3H, PC(CH3)d), 1.05 (dd, JH-P ) 16.5, JH-H ) 6.9, 3H,
PCHCH3), 0.80 (dd, JH-P ) 15.1, JH-H ) 7.0, 3H, PCHCH3),
0.79 (dd, JH-P ) 12.4, JH-H ) 7.3, 3H, PCHCH3). 31P{1H} NMR
(121.42 MHz, C6D6, 293 K): δ 24.2 (s). 13C{1H} NMR (75.42
MHz, C6D6, 293 K, plus APT): δ 159.4 (d, JC-P ) 10, CdNH),
142.9 (d, JC-P ) 2, CipsoPh), 140.3 (d, JC-P ) 8, dCH), 134.0
(CipsoPh), 132.0 (d, JC-P ) 22, PC)), 129.4 and 125.6 (both s,
Ph), 74.9 (s, Cp), 35.0 (d, JC-P ) 31, PCH), 27.7 (d, JC-P ) 33,
Preparation of [OsH(η5-C5H5){NHdC(p-C6H4CH3)-
CHdC(CH3)}(PHiPr2)]BF4 (8). A dark brown solution of 5
(182 mg, 0.34 mmol) in 7 mL of diethyl ether was treated with
HBF4‚Et2O (47 µL, 0.34 mmol) at 0 °C. Immediately, a yellow
solid appeared, and the mixture was allowed to react for 10
min. The product was washed with diethyl ether (2 × 2 mL),
separated by decantation, and dried in vacuo. Yield: 174 mg
(82%). Anal. Calcd for C22H33BF4NOsP: C, 42.65; H, 5.37; N,
2.26. Found: C, 42.69; H, 5.28; N, 2.27. IR (Nujol, cm-1): ν(NH)
3335 (m), ν(PH) 2344 (w), ν(OsH) 2061 (w), ν(CdN) 1560,
ν(BF4) 1051 (vs). 1H NMR (300 MHz, CD2Cl2, 293 K, plus
COSY): δ 10.54 (br, 1H, NH), 7.58 (d, JH-H ) 8.1, 2H, o-Ph),
7.28 (m, 3H, m-Ph + OsC(CH3)CH), 5.55 (s, 5H, C5H5), 4.46
(d, JH-P ) 369.9, 1H, PH), 2.99 (s, 3H, OsC(CH3)), 2.40 (s, 3H,
p-CH3), 2.36 (m, 1H, PCH), 1.78 (m, 1H, PCH), 1.20 (dd, JH-P
) 17.1, JH-H ) 6.9, 3H, PCHCH3), 1.13 (dd, JH-P ) 17.7, JH-H
) 6.9, 3H, PCHCH3), 1.06 (dd, JH-P ) 17.4, JH-H ) 6.9, 3H,
PCHCH3), 0.80 (dd, JH-P ) 17.4, JH-H ) 7.3, 3H, PCHCH3),
-12.44 (dd, JH-P ) 43.5, JH-H ) 3.6, 1H, Os-H). 31P{1H} NMR
(121.42 MHz, C6D6, 293 K): δ 21.0 (s). 13C{1H} NMR (75.42
PCH), 24.8 (s, PC(CH3)d), 21.0 (s, PCHCH3), 19.2 (d, JC-P
)
6, PCHCH3), 18.9 (d, JC-P ) 4, PCHCH3), 18.6 (s, PCHCH3).
MS (LSIMS+): m/z 587 (M+); 552 (M+ - Cl).
PreparationofOs(η5-C5H5){NH-C(p-C6H4CH3)-CH-C-
(CH3)}(PHiPr2) (5). A purple solution of 2 (216 mg, 0.38
mmol) in 8 mL of toluene was treated with sodium tetrahy-
drideborate (115 mg, 3.05 mmol), and 1 mL of methanol was
added. The slurry was allowed to react at room temperature
for 10 min, and then, the solvent was removed. The product
was extracted with pentane (20 mL), the resultant dark brown
solution was concentrated to dryness, and the product was
1
isolated as a brown oil.30 Yield: 182 mg (89%). H NMR (300
MHz, C6D6, 293 K, plus COSY): δ 8.79 (br, 1H, NH), 7.55 (s,
1H, OsC(CH3)CH), 7.50 (d, JH-H ) 8.1, 2H, o-Ph), 6.94 (d, JH-H
) 8.1, 2H, m-Ph), 4.71 (s, 5H, C5H5), 3.59 (dt, JH-P ) 336.6,
JH-H ) 3.6, 1H, PH), 3.39 (s, 3H, OsC(CH3)), 2.06 (s, 3H,
p-CH3), 1.79 (m, 2H, PCH), 0.95-0.83 (12H, PCHCH3). 31P-
{1H} NMR (121.42 MHz, C6D6, 293 K): δ 41.1 (s). 13C{1H}
NMR (75.42 MHz, C6D6, 293 K, plus APT, plus HSQC, plus
HMBC): δ 222.6 (d, JC-P ) 7, OsC), 178.8 (d, JC-P ) 4, CNH),
137.9 (s, p-Ph), 135.3 (s, CipsoPh), 129.4, 126.5, and 126.3 (all
s, Ph + OsC(CH3)CH), 72.0 (s, Cp), 38.8 (s, OsC(CH3)), 26.3
(d, JC-P ) 32, PCH), 25.9 (d, JC-P ) 29, PCH), 21.5 (s,
PCHCH3), 21.1 (s, p-CH3), 21.0 and 20.8 (both s, PCHCH3),
MHz, C6D6, 293 K, plus APT, plus HSQC): δ 194.7 (d, JC-P
)
16, OsC), 184.6 (s, CNH), 142.1 (s, CipsoPh), 134.9 (d, JC-P ) 3,
OsC(CH3)CH), 131.0 (s, CipsoPh), 129.9 and 127.4 (both s, Ph),
84.6 (s, Cp), 34.1 (d, JC-P ) 5, OsC(CH3)), 26.1 (d, JC-P ) 37,
PCH), 23.3 (d, JC-P ) 40, PCH), 21.2 (s, p-CH3), 20.9, 20.6,
19.7, and 18.4 (all s, PCHCH3). MS (LSIMS+): m/z 532 (M+
2H); 414 (M+ - H - PHiPr2).
-
Preparation of [OsH(η5-C5H5){NHdC(Ph)CHdC(CH3)}-
(PHiPr2)]BF4 (9). The same procedure described for 8 was
followed starting from 6 (90 mg, 0.17 mmol) and HBF4‚Et2O
(24 µL, 0.17 mmol). The product was isolated as a yellow solid.
Yield: 84 mg (80%). Anal. Calcd for C21H31BF4NOsP: C, 41.66;
H, 5.16; N, 2.31. Found: C, 41.50; H, 5.30; N, 2.21. IR (Nujol,
cm-1): ν(NH) 3343 (m), ν(OsH) 2055 (w), ν(CdN) 1556 (m),
ν(BF4) 1051 (vs). 1H NMR (300 MHz, CD2Cl2, 293 K, plus
COSY): δ 10.66 (br, 1H, NH), 7.71-7.49 (m, 5H, Ph), 7.32 (s,
1H, OsC(CH3)CH), 5.58 (s, 5H, C5H5), 4.47 (d, JH-P ) 369.6,
1H, PH), 3.00 (s, 3H, OsC(CH3)), 2.35 (m, 1H, PCH), 1.78 (m,
1H, PCH), 1.21 (dd, JH-P ) 16.8, JH-H ) 7.0, 3H, PCHCH3),
20.4 (d, JC-P ) 3, PCHCH3). MS (LSIMS+): m/z 532 (M+
H).
-
Preparation of Os(η5-C5H5){NH-C(Ph)-CH-C(CH3)}-
(PHiPr2) (6). The same procedure described for 5 was followed,
starting from 3 (91 mg, 0.16 mmol) and sodium tetrahy-
drideborate (50 mg, 1.40 mmol). The product was isolated as
1
a brown oil.30 Yield: 62 mg (73%). H NMR (300 MHz, C6D6,
(30) All our attempts to achieve a valid elemental analysis deter-
mination for this complex were unsuccessful due to the presence of
impurity traces (including solvents) in the sample.

1232 Organometallics, Vol. 24, No. 6, 2005
Baya et al.
Table 3. Crystal Data and Data Collection and
Refinement for 3 and 10
1.14 (dd, JH-P ) 16.8, JH-H ) 7.5, 3H, PCHCH3), 1.08 (dd, JH-P
) 16.8, JH-H ) 7.2, 3H, PCHCH3), 0.82 (dd, JH-P ) 17.4, JH-H
) 7.2, 3H, PCHCH3), -12.40 (dd, JH-P ) 43.8, JH-H ) 3.9, 1H,
OsH). 31P{1H} NMR (121.42 MHz, C6D6, 293 K): δ 20.5 (s).
13C{1H} NMR (75.42 MHz, C6D6, 293 K, plus APT, plus
HSQC): δ 195.7 (d, JC-P ) 16, OsC), 185.0 (s, CNH), 135.2 (d,
JC-P ) 3, OsC(CH3)CH), 133.9 (s, CipsoPh), 131.6, 129.4, and
127.6 (all s, Ph), 84.8 (s, Cp), 34.4 (d, JC-P ) 5, OsC(CH3)),
26.2 (d, JC-P ) 37, PCH), 23.5 (d, JC-P ) 40, PCH), 21.1 (s,
PCHCH3), 20.8 (d, JC-P ) 2, PCHCH3), 20.0 and 18.6 (both s,
PCHCH3). MS (LSIMS+): m/z 520 (M+); 400 (M+ - H -
PHiPr2).
3
10
Crystal Data
21H29ClNOsP1
0.5C5H10
588.15
purple, irregular block light yellow, block
triclinic, P1h
formula
C
C21H30BClF4NOsP
639.89
molecular wt
color and habit
symmetry, space
group
monoclinic, P21
a, Å
b, Å
c, Å
R, deg
9.4980(6)
11.9856(8)
21.0781(14)
78.2910(10)
82.5210(10)
83.4590(10)
2320.1(3)
4
9.6107(5)
18.7787(10)
13.2032(7)
Preparation of [OsH(η5-C5H5){NHdC(p-C6H4Cl)CHdC-
(CH3)}(PHiPr2)]BF4 (10). The same procedure described for
8 was followed starting from 7 (159 mg, 0.29 mmol) and HBF4‚
Et2O (39 µL, 0.29 mmol). The product was isolated as a yellow
solid. Yield: 151 mg (82%). Anal. Calcd for C21H30BClF4-
NOsP: C, 39.41; H, 4.72; N, 2.19. Found: C, 39.70; H, 4.98;
N, 2.14. IR (Nujol, cm-1): ν(NH) 3332 (w), ν(PH) 2345 (w),
ν(OsH) 2062 (w), ν(CdN) 1557 (m), ν(BF4) 1010 (vs). 1H NMR
(300 MHz, CD2Cl2, 293 K, plus COSY): δ 10.81 (br, 1H, NH),
7.67 (d, JH-H ) 8.7, 2H, o-Ph), 7.48 (d, JH-H ) 8.7, 2H, m-Ph),
â, deg
99.6800(10)
γ, deg
V, Å3
2915.1(10)
4
1.809
Z
Dcalc, g cm-3
1.620
Data Collection and Refinement
Bruker Smart APEX
0.71073
diffractometer
λ(Mo KR), Å
monochromator
scan type
graphite oriented
ω scans
µ, mm-1
5.689
3, 57
100
5.650
7.29 (s, 1H, OsC(CH3)CH), 5.58 (s, 5H, C5H5), 4.46 (d, JH-P
)
369.0, 1H, PH), 3.00 (s, 3H, OsC(CH3)), 2.35 (m, 1H, PCH),
1.78 (m, 1H, PCH), 1.21 (dd, JH-P ) 17.1, JH-H ) 7.2, 3H,
PCHCH3), 1.14 (dd, JH-P ) 17.7, JH-H ) 7.2, 3H, PCHCH3),
1.08 (dd, JH-P ) 17.4, JH-H ) 7.2, 3H, PCHCH3), 0.81 (dd, JH-P
) 17.4, JH-H ) 7.2, 3H, PCHCH3), -12.34 (dd, JH-P ) 43.8,
JH-H ) 3.9, 1H, OsH). 31P{1H} NMR (121.42 MHz, C6D6, 293
K): δ 19.9 (s). 13C{1H} NMR (75.42 MHz, C6D6, 293 K, plus
APT, plus HMQC, plus HMBC): δ 196.4 (d, JC-P ) 16, OsC),
183.3 (s, CNH), 137.3 (s, CipsoPh), 134.8 (d, JC-P ) 3, OsC-
(CH3)CH), 132.1 (s, CipsoPh), 129.4 and 128.9 (both s, Ph), 84.7
(s, Cp), 34.2 (d, JC-P ) 5, OsC(CH3)), 26.2 (d, JC-P ) 36, PCH),
23.4 (d, JC-P ) 39, PCH), 20.9, 20.5, 19.7, and 18.4 (all s,
PCHCH3). MS (LSIMS+): m/z 554 (M+); 434 (M+ - H -
PHiPr2).
2θ, range, deg
temp, K
3, 57
100
no. of data colld
no. of unique data 10 772 (Rint ) 0.0311)
28 470
29 806
11 396 (Rint ) 0.0313)
no. of params/
restraints
520/0
561/31
R1a[F2 > 2σ(F2)]
wR2b[all data]
Sc[all data]
0.0242
0.0453
0.863
0.0389
0.0704
0.970
2
2
a R1(F) ) ∑||Fo| - |Fc||/∑|Fo|. b wR2(F2) ) {∑[w(Fo - Fc )2]/
∑[w(Fo2)2]}1/2 c Goof ) S ) {∑[Fo - Fc )2]/(n - p)}1/2, where n is
.
2
2
the number of reflections, and p is the number of refined
parameters.
minimizing w(Fo2 - Fc2)2. A molecule of pentane was observed
in 3 in the last cycles of refinement. On the basis of the
systematic absences two space groups were possible for 10,
P21 and P21/m. The structure was only correctly resolved on
the asymmetric one, and the phosphine ligand of one of the
two molecules of the asymmetric unit was observed severely
disordered. The hydride ligand of 10 was observed in the
nondisordered molecule but did not refine properly, because
of that finally was refined with restrained Os-H distance and
thermal parameter. Weighted R factors (Rw) and goodness of
fit (S) are based on F2; conventional R factors are based on F.
A summary of crystal data and data collection and refine-
ment details is reported in Table 3.
X-ray Analysis of Complexes 3 and 10. Crystals suitable
for the X-ray diffraction were obtained by cooling at 4 °C a
solution of 3 in diethyl ether and by slow diffusion of diethyl
ether into a concentrated solution of 10 in dichloromethane.
Two irregular crystals of size 0.30 × 0.28 × 0.10 mm (3) and
0.20 × 0.16 × 0.12 mm (10) were mounted on a Bruker Smart
APEX CCD diffractometer at 100.0(2) K equipped with a
normal focus, 2.4 kW sealed tube source (Mo radiation, λ )
0.71073 Å) operating at 50 kV and 40 mA. Data were collected
over the complete sphere by a combination of four sets. Each
frame exposure time was 10 s covering 0.3° in ω. The cell
parameters were determined and refined by least-squares fit
of 5104 (3) or 8759 (10) collected reflections. The first 100
frames were collected at the end of the data collection to
monitor crystal decay. Absorption correction was performed
with the SADABS program.31 Lorentz and polarization cor-
rections were also performed. The structures were solved by
Patterson and Fourier methods and refined by full matrix
least-squares using the Bruker SHELXTL program package32
Acknowledgment. Financial support from the
MCYT of Spain (Proyects BQU2002-00606 and PPQ2000-
0488-P4-02) is acknowledged.
Supporting Information Available: 1H, 31P{1H}, 13C{1H},
and 1H-13C HSQC NMR spectra for 5, 6, and 7, and tables of
crystallographic data and bond lengths and angles for 3 and
10. This material is available free of charge via the Internet
at http://pubs.acs.org.
(31) Blessing, R. H. Acta Crystallogr., Sect. A 1995, 51, 33.
(32) SHELXTL Package v. 6.1; Bruker Analytical, X-ray Systems:
Madison, WI, 2000.
OM049178A