Assembly of an allenylidene ligand, a terminal alkyne, and an acetonitrile molecule: Formation of osmacyclopentapyrrole derivatives

Article abstract of DOI:10.1021/ja058355b

Treatment in acetonitrile at -30 °C of the hydride-alkenylcarbyne complex [OsH(≡CCH= CPh₂)(CH₃CN)₂(P ⁱPr₃)₂][BF₄]₂ (1) with ^lBuOK produces the selective deprotonation of the alkenyl substituent of the carbyne and the formation of the bis-solvento hydride-allenylidene derivative [OsH(=C=C= CPh₂)(CH₃CN)₂(P ⁱPr₃)₂]BF₄ (2), which under carbon monoxide atmosphere is converted into [Os(CH=C= CPh₂)(CO)(CH ₃CN)₂(PⁱPr₃)₂]BF ₄ (3). When the treatment of 1 with ^lBuOK is carried out in dichloromethane at room temperature, the fluoro-alkenylcarbyne [OsHF(≡CCH=CPh₂)(CH₃CN)(PⁱPr ₃)₂]BF₄ (4) is isolated. Complex 2 reacts with terminal alkynes. The reactions with phenylacetylene and cyclohexylacetylene afford [Os{(E)-CH=CHR}(=C=C=CPh₂)(CH₃CN) ₂(PⁱPr₃)₂]BF₄ (R = Ph (5), Cy (6)), containing an alkenyl ligand beside the allenylidene, while the reaction with acetylene in dichloromethane at -20 °C gives the hydride-allenylidene-π-alkyne [OsH(=C=C=CPh₂)(η²- HC≡CH)(PⁱPr₃)₂]BF₄ (7), with the alkyne acting as a four-electron donor ligand. In acetonitrile under reflux, complexes 5 and 6 are transformed into the osmacyclopentapyrrole compounds [Os{C=C(CPh₂CR=CH)CMe=NH}(CH₃CN)₂]BF ₄ (R = Ph (8), Cy (9)), as a result of the assembly of the allenylidene ligand, the alkenyl group, and an acetonitrile molecule. The X-ray structures of 2, 5, and 8 are also reported.

Full text of DOI:10.1021/ja058355b

Published on Web 03/02/2006
Assembly of an Allenylidene Ligand, a Terminal Alkyne, and
an Acetonitrile Molecule: Formation of
Osmacyclopentapyrrole Derivatives
Tamara Bolan˜o, Ricardo Castarlenas, Miguel A. Esteruelas,* and Enrique On˜ate
Contribution from the Departamento de Qu´ımica Inorga´nica, Instituto de Ciencia de Materiales
de Arago´n, UniVersidad de Zaragoza-CSIC, 50009 Zaragoza, Spain
Received December 9, 2005; E-mail: maester@posta.unizar.es
Abstract: Treatment in acetonitrile at -30 °C of the hydride-alkenylcarbyne complex [OsH(tCCHd
CPh2)(CH3CN)2(PiPr3)2][BF4]2 (1) with tBuOK produces the selective deprotonation of the alkenyl substituent
of the carbyne and the formation of the bis-solvento hydride-allenylidene derivative [OsH(dCdCd
CPh2)(CH3CN)2(PiPr3)2]BF4 (2), which under carbon monoxide atmosphere is converted into [Os(CHdCd
CPh2)(CO)(CH3CN)2(PiPr3)2]BF4 (3). When the treatment of 1 with tBuOK is carried out in dichloromethane
at room temperature, the fluoro-alkenylcarbyne [OsHF(tCCHdCPh2)(CH3CN)(PiPr3)2]BF4 (4) is isolated.
Complex 2 reacts with terminal alkynes. The reactions with phenylacetylene and cyclohexylacetylene afford
[Os{(E)-CHdCHR}(dCdCdCPh2)(CH3CN)2(PiPr3)2]BF4 (R ) Ph (5), Cy (6)), containing an alkenyl ligand
beside the allenylidene, while the reaction with acetylene in dichloromethane at -20 °C gives the hydride-
allenylidene-π-alkyne [OsH(dCdCdCPh2)(η2-HCtCH)(PiPr3)2]BF4 (7), with the alkyne acting as a four-
electron donor ligand. In acetonitrile under reflux, complexes 5 and 6 are transformed into the
osmacyclopentapyrrole compounds [Os{CdC(CPh2CRdCH)CMedNH}(CH3CN)2]BF4 (R ) Ph (8), Cy (9)),
as a result of the assembly of the allenylidene ligand, the alkenyl group, and an acetonitrile molecule. The
X-ray structures of 2, 5, and 8 are also reported.
Introduction
fragment stabilizing the unsaturated ligand. According to the
behavior reported until now and in agreement with the presence
of electrophilic and nucleophilic sites in the C3 chain, the
allenylidene complexes have been classified in three groups:5e
R-electrophiles, γ-electrophiles, and nucleophiles. While R- and
The development of highly efficient and selective synthetic
methods is one of the tasks for chemical science. In this context,
to assemble organic fragments, in the manner like a child plays
with a LEGO, is a fascinating challenge.
Allenylidene complexes belong to the series of unsaturated
derivatives LmMdC(dC)ndCRR′ with n > 0.1 They are
generally prepared by following Selegue’s protocol involving
propargyl alcohols, which are converted into CdCdCRR′ units
in the coordination sphere of a transition metal center by
elimination of water.2 Recent studies indicate that these C3-
unsaturated species are an option with a promising future, in
both stoichiometric3 and catalytic4 processes. Their potentiality
can become greater than that of the classical carbene derivatives.
It stems from the presence in the carbon chain of both
electrophilic (CR and Cγ) and nucleophilic (Câ) sites, which
provide unusually versatile reactivities.5
The allenylidene ligands coordinate to the metal center as
σ-donor and π-acceptor groups. The resulting bond produces a
charge transfer from the metal center to the allenylidene, which
mainly depends on the co-ligands. As a result, the reactivity of
the C3-organic unit is a function of the particular metallic
(3) See for example: (a) Roth, G.; Reindl, D.; Gockel, M.; Troll, C.; Fischer,
H. Organometallics 1998, 17, 1393. (b) Gil-Rubio, J.; Weberndo¨rfer, B.;
Werner, H. Angew. Chem., Int. Ed. 2000, 39, 786. (c) Ilg, K.; Werner, H.
Organometallics 2001, 20, 3782. (d) Cadierno, V.; Conejero, S.; Gamasa,
M. P.; Gimeno, J.; Pe´rez-Carren˜o, E.; Garc´ıa-Granda, S. Organometallics
2001, 20, 3175. (e) Bustelo, E.; Jime´nez-Tenorio, M.; Mereiter, K.; Puerta,
M. C.; Valerga, P. Organometallics 2002, 21, 1903. (f) Mantovani, N.;
Marvelli, L.; Rossi, R.; Bertolasi, V.; Bianchini, C.; de los R´ıos, I.;
Peruzzini, M. Organometallics 2002, 21, 2382. (g) Cadierno, V.; Conejero,
S.; Gamasa, M. P.; Gimeno, J.; Falvello, L. R.; Llusar, R. M. Organome-
tallics 2002, 21, 3716. (h) Cadierno, V.; Conejero, S.; Gamasa, M. P.;
Gimeno, J. Organometallics 2002, 21, 3837. (i) Conejero, S.; D´ıez, J.;
Gamasa, M. P.; Gimeno, J.; Garc´ıa-Granda, S. Angew. Chem., Int. Ed. 2002,
41, 3439. (j) Werner, H.; Wiedemann, R.; Laubender, M.; Windmu¨ller,
B.; Steinert, P.; Gevert, O.; Wolf, J. J. Am. Chem. Soc. 2002, 124, 6966.
(k) Fischer, H.; Szesni, N.; Roth, G.; Burzlaff, N.; Weibert, B. J. Organomet.
Chem. 2003, 683, 301. (l) van Slageren, J.; Winter, R. F.; Klein, A.;
Hartmann, S. J. Organomet. Chem. 2003, 670, 137. (m) Harbort, R.-C.;
Hartmann, S.; Winter, R. F.; Klinkhammer, K. W. Organometallics 2003,
22, 3171. (n) Jime´nez-Tenorio, M.; Palacios, M. D.; Puerta, M. C.; Valerga,
P. J. Organomet. Chem. 2004, 689, 2776. (o) Szesni, N.; Weibert, B.;
Fischer, H. Inorg. Chim. Acta 2004, 357, 1789. (p) Conejero, S.; Diez, J.;
Gamasa, M. P.; Gimeno, J. Organometallics 2004, 23, 6299. (q) D´ıez, J.;
Gamasa, M. P.; Gimeno, J.; Lastra, E.; Villar, A. Organometallics 2005,
24, 1410. (r) Venaˆncio, A. I. F.; Guedes da Silva, M. F. C.; Martins, L. M.
D. R. S.; Frau´sto da Silva, J. J. R.; Pombeiro, A. J. L. Organometallics
2005, 24, 4654. (s) Pavlik, S.; Mereiter, K.; Puchberger, M.; Kirchner, K.
Organometallics 2005, 24, 3561. (t) Abd-Elzaher, M. M.; Weibert, B.;
Fischer, H. Organometallics 2005, 24, 1050. (u) Drexler, M.; Haas, T.;
Yu, S.-M.; Beckmann, H. S. G.; Weibert, B.; Fischer, H. J. Organomet.
Chem. 2005, 690, 3700. (v) Szesni, N.; Weibert, B.; Fischer, H. Inorg.
Chim. Acta 2005, 358, 1645.
(1) (a) Werner, H. Chem. Commun. 1997, 903. (b) Bruce, M. I. Chem. ReV.
1998, 98, 2797. (c) Cadierno, V.; Gamasa, M. P.; Gimeno, J. Eur. J. Inorg.
Chem. 2001, 571. (d) Selegue, J. P. Coord. Chem. ReV. 2004, 248, 1543.
(e) Winter, R. F.; Za´lisˇ, S. Coord. Chem. ReV. 2004, 248, 1565. (f) Cadierno,
V.; Gamasa, M. P.; Gimeno, J. Coord. Chem. ReV. 2004, 248, 1627.
(2) Selegue, J. P. Organometallics 1982, 1, 217.
9
10.1021/ja058355b CCC: $33.50 © 2006 American Chemical Society
J. AM. CHEM. SOC. 2006, 128, 3965-3973
3965

A R T I C L E S
Bolan˜o et al.
γ-electrophiles have attracted great attention,6 nucleophiles have
been very little studied. The most noticeable feature of the latter
is their tendency to add a proton at the Câ atom, to afford R,â-
unsaturated alkenylcarbyne derivatives.5e,6n,7
The acid-base properties are among the most important and
fundamental characteristics of the metal-hydride bond. They
depend on the electron density of the metal fragment. The pKa
values increase as the electron richness of the metal center also
increases.11 In some cases, the hydride complexes of electron-
rich metals also bear a carbyne ligand.12 Those with a CH2R
group are known to have rather acidic properties.13 In agreement
with the acidity of the Câ-H bond, a few hydride-vinylidene
complexes have been prepared by selective deprotonation of a
carbyne group in the presence of a hydride ligand.14
Hydride-carbyne complexes of electron-rich metal centers
are inert toward the 1,2-hydrogen shift from the metal to the
carbyne carbon atom.15 Recently, we have reported evidences
proving that the activation energy for the hydride migration
increases as the electron richness of the metal center augments,
that is, as the acidity of the hydride ligand decreases. Thus, in
contrast to OsHCl2(tCCHdCR2)(PiPr3)2, in acetonitrile, the
dicationic hydride-alkenylcarbyne complexes [OsH(tCCHd
CR2)S2(PiPr3)2][BF4]2 (R ) Ph, Me; S ) H2O, CH3CN) are
converted into dicationic alkenylcarbene derivatives as expected
for an electron-poor metal center.16
In this paper we show (i) the selective deprotonation of the
alkenyl substituent of the carbyne group of complex [OsH(t
CCHdCPh2)(CH3CN)2(PiPr3)2][BF4]2 in the presence of the
hydride ligand, despite the electron-poor character of the metal
center, and the corresponding formation of a novel hydride-
allenylidene compound; (ii) the use of the hydride ligand as a
useful anchor to nail alkynes beside an allenylidene; and (iii)
the assembly of the alkynes, the allenylidene, and acetonitrile
to form osmacyclopentapyrrole derivatives.
Hydrides are one of the best anchors to nail unsaturated
organic molecules in transition metal compounds. As a conse-
quence, transition metal hydride complexes are involved in many
stoichiometric and catalytic reactions, including carbon-carbon
and carbon-heteroatom coupling processes.8 Hydride-al-
lenylidene compounds are very rare. As far as we know, reported
derivatives of this type only include IrHCl2(dCdCdCPhR)-
(PiPr3)2 (R ) Ph, tBu), which have been obtained by oxidative
addition of HCl to the corresponding iridium (I) starting
complexes IrCl(dCdCdCPhR)(PiPr3)2.9 Hydride-allenylidene
species have been also proposed as intermediates for the
formation of Os(CHdCdCPh2)Cl2(NO)(PiPr2R)2 (R ) iPr, Ph),
by treatment of OsHCl{CtCC(OH)Ph2}(NO)(PiPr2R)2 with
acidic alumina.10
(4) See for example: (a) Fu¨rstner, A.; Picquet, M.; Bruneau, C.; Dixneuf, P.
H. Chem. Commun. 1998, 1315. (b) Picquet, M.; Bruneau, C.; Dixneuf, P.
H. Chem. Commun. 1998, 2249. (c) Picquet, M.; Touchard, D.; Bruneau,
C.; Dixneuf, P. H. New J. Chem. 1999, 141. (d) Fu¨rstner, A.; Liebl, M.;
Lehmann, C. W.; Picquet, M.; Kunz, R.; Bruneau, C.; Touchard, D.;
Dixneuf, P. H. Chem.sEur. J. 2000, 6, 1847. (e) Nishibayashi, Y.; Wakiji,
I.; Hidai, M. J. Am. Chem. Soc. 2000, 122, 11019. (f) Nishibayashi, Y.;
Inada, Y.; Hidai, M.; Uemura, S. J. Am. Chem. Soc. 2002, 124, 7900. (g)
Castarlenas, R.; Se´meril, D.; Noels, A. F.; Demonceau, A.; Dixneuf, P. H.
J. Organomet. Chem. 2002, 663, 235. (h) Nishibayashi, Y.; Inada, Y.; Hidai,
M.; Uemura, S. J. Am. Chem. Soc. 2003, 125, 6060. (i) Ammal, S. C.;
Yoshikai, N.; Inada, Y.; Nishibayashi, Y.; Nakamura, E. J. Am. Chem.
Soc. 2005, 127, 9428. (j) Trost, B. M.; Frederiksen, M. U.; Rudd, M. T.
Angew. Chem., Int. Ed. 2005, 44, 6630.
(5) (a) Berke, H.; Huttner, G.; von Seyerl, J. Z. Naturforsch. 1981, 363, 1277.
(b) Cadierno, V.; Gamasa, M. P.; Gimeno, J.; Gonza´lez-Cueva, M.; Lastra,
E.; Borge, J.; Garc´ıa-Granda, S.; Pe´rez-Carren˜o, E. Organometallics 1996,
15, 2137. (c) Edwards, A. J.; Esteruelas, M. A.; Lahoz, F. J.; Modrego, J.;
Oro, L. A.; Schrickel, J. Organometallics 1996, 15, 3556. (d) Esteruelas,
M. A.; Go´mez, A. V.; Lo´pez, A. M.; Modrego, J.; On˜ate, E. Organome-
tallics 1997, 16, 5826. (e) 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. (f) Wong, C.-Y.; Che, C.-M.; Chan, M.
C. W.; Leung, K.-H.; Phillips, D. L.; Zhu, N. J. Am. Chem. Soc. 2004,
126, 2501.
(6) See for example: (a) Esteruelas, M. A.; Go´mez, A. V.; Lahoz, F. J.; Lo´pez,
A. M.; On˜ate, E.; Oro, L. A. Organometallics 1996, 15, 3423. (b) Gamasa,
M. P.; Gimeno, J.; Gonza´lez-Bernardo, C.; Borge, J.; Garc´ıa-Granda, S.
Organometallics 1997, 16, 2483. (c) Esteruelas, M. A.; Go´mez, A. V.;
Lo´pez, A. M.; On˜ate, E.; Ruiz, N. Organometallics 1998, 17, 2297. (d)
Esteruelas, M. A.; Go´mez, A. V.; Lo´pez, A. M.; On˜ate, E. Organometallics
1998, 17, 3567. (e) Esteruelas, M. A.; Go´mez, A. V.; Lo´pez, A. M.; Puerta,
M. C.; Valerga, P. Organometallics 1998, 17, 4959. (f) Esteruelas, M. A.;
Go´mez, A. V.; Lo´pez, A. M.; Modrego, J.; On˜ate, E. Organometallics 1998,
17, 5434. (g) Esteruelas, M. A.; Go´mez, A. V.; Lo´pez, A. M.; On˜ate, E.;
Ruiz, N. Organometallics 1999, 18, 1606. (h) Bernad, D. J.; Esteruelas,
M. A.; Lo´pez, A. M.; Modrego, J.; Puerta, M. C.; Valerga, P. Organome-
tallics 1999, 18, 4995. (i) Esteruelas, M. A.; Go´mez, A. V.; Lo´pez, A. M.;
Oliva´n, M.; On˜ate, E.; Ruiz, N. Organometallics 2000, 19, 4. (j) Bernad,
D. J.; Esteruelas, M. A.; Lo´pez, A. M.; Oliva´n, M.; On˜ate, E.; Puerta, M.
C.; Valerga, P. Organometallics 2000, 19, 4327. (k) Baya, M.; Buil, M.
L.; Esteruelas, M. A.; Lo´pez, A. M.; On˜ate, E.; Rodr´ıguez, J. R.
Organometallics 2002, 21, 1841. (l) Buil, M. L.; Esteruelas, M. A.; Lo´pez,
A. M.; On˜ate, E. Organometallics 2003, 22, 162. (m) Buil, M. L.;
Esteruelas, M. A.; Lo´pez, A. M.; On˜ate, E. Organometallics 2003, 22, 5274.
(n) Asensio, A.; Buil, M. L.; Esteruelas, M. A.; On˜ate, E. Organometallics
2004, 23, 5787.
Results and Discussion
1. Selective Deprotonation of the Alkenyl Substituent of
an Alkenylcarbyne Ligand: Formation and Characteriza-
tion of a Novel Hydride-Allenylidene Derivative. Despite
the expected acidity of the hydride ligand of [OsH(tCCHd
(11) (a) Angelici, R. J. Acc. Chem. Res. 1995, 28, 51. (b) Abdur-Rashid, K.;
Fong, T. P.; Greaves, B.; Gusev, D. G.; Hinman, J. G.; Landau, S. E.;
Lough, A. J.; Morris, R. H. J. Am. Chem. Soc. 2000, 122, 9155.
(12) (a) Espuelas, J.; Esteruelas, M. A.; Lahoz, F. J.; Oro, L. A.; Ruiz, N. J.
Am. Chem. Soc. 1993, 115, 4683. (b) Leeaphon, M.; Ondracek, A. L.;
Thomas, R. J.; Fanwick, P. E.; Walton, R. A. J. Am. Chem. Soc. 1995,
117, 9715. (c) Spivak, G. J.; Coalter, J. N.; Oliva´n, M.; Eisenstein, O.;
Caulton, K. G. Organometallics 1998, 17, 999. (d) Werner, H.; Jung, S.;
Weberndo¨rfer, B.; Wolf, J. Eur. J. Inorg. Chem. 1999, 951. (e) Esteruelas,
M. A.; Gonza´lez, A. I.; Lo´pez, A. M.; On˜ate, E. Organometallics 2003,
22, 414. (f) Ozerov, O. V.; Huffman, J. C.; Watson, L. A.; Caulton, K. G.
Organometallics 2003, 22, 2539. (g) Ozerov, O. V.; Watson, L. A.; Pink,
M.; Caulton, K. G. J. Am. Chem. Soc. 2004, 126, 6363. (h) Esteruelas, M.
A.; Gonza´lez, A. I.; Lo´pez, A. M.; On˜ate, E. Organometallics 2004, 23,
4858.
(13) (a) Esteruelas, M. A.; Lo´pez, A. M.; Ruiz, N.; Tolosa, J. I. Organometallics
1997, 16, 4657. (b) Esteruelas, M. A.; Oliva´n, M.; On˜ate, E.; Ruiz, N.;
Tajada, M. A. Organometallics 1999, 18, 2953. (c) Buil, M. L.; Eisenstein,
O.; Esteruelas, M. A.; Garc´ıa-Yebra, C.; Gutie´rrez-Puebla, E.; Oliva´n, M.;
On˜ate, E.; Ruiz, N.; Tajada, M. A. Organometallics 1999, 18, 4949. (d)
Castarlenas, R.; Esteruelas, M. A.; On˜ate, E. Organometallics 2001, 20,
3283. (e) Baya, M.; Esteruelas, M. A.; On˜ate, E. Organometallics 2001,
20, 4875. (f) Baya, M.; Esteruelas, M. A.; On˜ate, E. Organometallics 2002,
21, 5681.
(14) (a) Bourgault, M.; Castillo, A.; Esteruelas, M. A.; On˜ate, E.; Ruiz, N.
Organometallics 1997, 16, 636. (b) Crochet, P.; Esteruelas, M. A.; Lo´pez,
A. M.; Mart´ınez, M.-P.; Oliva´n, M.; On˜ate, E.; Ruiz, N. Organometallics
1998, 17, 4500. (c) Barrio, P.; Esteruelas, M. A.; On˜ate, E. Organometallics
2002, 21, 2491. (d) Baya, M.; Esteruelas, M. A. Organometallics 2002,
21, 2332.
(15) (a) Spivak, G. J.; Coalter, J. N.; Oliva´n, M.; Eisenstein, O.; Caulton, K. G.
Organometallics 1998, 17, 999. (b) Spivak, G. J.; Caulton, K. G.
Organometallics 1998, 17, 5260. (c) Caulton, K. G. J. Organomet. Chem.
2001, 617-618, 56. (d) Jacobsen, H. J. Organomet. Chem. 2003, 674, 50.
(16) Bolan˜o, T.; Castarlenas, R.; Esteruelas, M. A.; Modrego, J.; On˜ate, E. J.
Am. Chem. Soc. 2005, 127, 11184.
(7) (a) Crochet, P.; Esteruelas, M. A.; Lo´pez, A. M.; Ruiz, N.; Tolosa, J. I.
Organometallics 1998, 17, 3479. (b) Esteruelas, M. A.; Lo´pez, A. M.;
On˜ate, E.; Royo, E. Organometallics 2004, 23, 3021. (c) Esteruelas, M.
A.; Lo´pez, A. M. Organometallics 2005, 24, 3584.
(8) See for example: (a) Esteruelas, M. A.; Oro, L. A. Chem. ReV. 1998, 98,
577. (b) Esteruelas, M. A.; Garc´ıa-Yebra, C.; Oliva´n, M.; On˜ate, E.; Tajada,
M. A. Organometallics 2000, 19, 5098. (c) Esteruelas, M. A.; Oro, L. A.
AdV. Organomet. Chem. 2001, 47, 1. (d) Esteruelas, M. A.; Lo´pez, A. M.
In Recent AdVances in Hydride Chemistry; Peruzzini, M., Poli, R., Eds.;
Elsevier: Amsterdam, 2001; Chapter 7, pp 189-248. (e) Castarlenas, R.;
Esteruelas, M. A.; On˜ate, E. Organometallics 2001, 20, 2294. (f) Esteruelas,
M. A.; Herrero, J.; Lo´pez, A. M.; Oliva´n, M. Organometallics 2001, 20,
3202. (g) Cobo, N.; Esteruelas, M. A.; Gonza´lez, F.; Herrero, J.; Lo´pez,
A. M.; Lucio, P.; Oliva´n, M. J. Catal. 2004, 223, 319.
(9) Ilg, K.; Werner, H. Chem.sEur. J. 2001, 7, 4633.
(10) Werner, H.; Flu¨gel, R.; Windmu¨ller, B.; Michenfelder, A.; Wolf, J.
Organometallics 1995, 14, 612.
9
3966 J. AM. CHEM. SOC. VOL. 128, NO. 12, 2006

Formation of Osmacyclopentapyrrole Derivatives
A R T I C L E S
the hydride ligand trans disposed to N(1), and the allenylidene
group trans disposed to N(2) (N(2)-Os-C(1) ) 176.2(2)°).
The diphenylallenylidene ligand is bonded to the metal in a
nearly linear fashion with Os-C(1)-C(2) and C(1)-C(2)-C(3)
angles of 177.5(5) and 173.2(7)°, respectively. The Os-C(1),
C(1)-C(2), and C(2)-C(3) bond lengths of 1.854(6), 1.275-
(8), and 1.347(8) Å, respectively, compare well with those
reported for the previously structurally characterized osmium-
allenylidene complexes.5b,6a,7a,17 In this context, it should be
noted that C(1)-C(2) and C(2)-C(3) are shorter and longer,
respectively, than the bond length expected for a carbon-carbon
double bond (about 1.30 Å), indicating a substantial contribution
of the canonical form [M]--CtC-C+Ph2 to the structure of
2. A similar conclusion has been reached in structural analysis
of other allenylidene complexes.1b,c
In agreement with the presence of the hydride and the
allenylidene ligands in 2, its IR spectrum in Nujol shows the
characteristic ν(Os-H) and ν(CdCdC) bands for these ligands
at 2129 and 1886 cm-1, respectively. In the 1H NMR spectrum
in dichloromethane-d2, the hydride resonance appears at -10.66
ppm, as a triplet (JH-P ) 17.5 Hz). In the 13C{1H} NMR
spectrum, the allenylidene ligand gives rise to a singlet at 137.5
ppm, corresponding to the Cγ atom, and two triplets at 267.8
(JC-P ) 13.4 Hz) and 252.2 ppm (JC-P ) 8.1 Hz), which are
assigned to the CR and Câ atoms, respectively, on the basis of
the HMBC spectrum. The 31P{1H} spectrum contains a singlet
at 11.8 ppm.
Figure 1. Molecular diagram of the cation of complex [OsH(dCdCd
CPh2)(CH3CN)2(PiPr3)2]BF4 (2). Selected bond distances (Å) and angles
(deg): Os-P(1) 2.3997(17), Os-P(2) 2.3797(17), Os-N(1) 2.218(5), Os-
N(1) 2.218(5), Os-N(2) 2.116(5), Os-C(1) 1.854(6), Os-H(01) 1.57(1),
C(1)-C(2) 1.275(8), C(2)-C(3) 1.347(8), P(1)-Os-P(2) 167.89(5), N(1)-
Os-N(2) 85.93(18), N(1)-Os-H(01) 169.6(19), N(2)-Os-C(1) 176.2-
(2), Os-C(1)-C(2) 177.5(5), C(1)-C(2)-C(3) 173.2(7).
Scheme 1
Complex 2 is immediately converted into the allenyl deriva-
tive [Os(CHdCdCPh2)(CO)(CH3CN)2(PiPr3)2]BF4 (3) in dichlo-
romethane under 1 atm of carbon monoxide. The transformation
of 2 into 3 involves the migratory insertion of the allenylidene
ligand into the metal-hydride bond and the coordination of
carbon monoxide to the osmium atom.
Complex 3 is isolated as a red solid in 86% yield. In the IR
spectrum of this compound in Nujol, the most noticeable feature
is the presence of a ν(CO) band at 1927 cm-1. In the 1H NMR
spectrum in dichloromethane-d2 at room temperature, the CR-H
resonance of the allenyl ligand appears at 7.06 ppm, as a triplet
(JH-P ) 2.4 Hz). The mutually cis disposition of the acetonitrile
molecules is strongly supported by the 13C{1H} NMR spectrum,
which shows four singlets for these ligands at 125.6 and 125.4
(CN), and 4.1 and 3.4 (CH3) ppm. The CO resonance is observed
at 183.5 ppm. The allenyl ligand displays a singlet at 101.0
ppm, corresponding to the Cγ atom, and two triplets at 206.1
(JC-P ) 2.6 Hz) and 69.1 ppm (JC-P ) 7.7 Hz), due to the Câ
and CR atoms, respectively. The 31P{1H} NMR spectrum shows
a singlet at 3.7 ppm.
CPh2)(CH3CN)2(PiPr3)2][BF4]2 (1), the treatment at -30 °C of
acetonitrile solutions of this dicationic hydride-alkenylcarbyne
t
complex with 1.5 equiv of BuOK produces the selective
abstraction of the Câ-H hydrogen atom of the alkenylcarbyne
group. The abstraction of the latter instead of the hydride ligand
could be a consequence of the steric requirement of the base
and/or of the fact of that the abstraction of the hydride involves
the reduction of the metal center from +2 to 0. The deproto-
nation gives rise to the formation of the monocationic hydride-
allenylidene derivative [OsH(dCdCdCPh2)(CH3CN)2(PiPr3)2]-
BF4 (2), which is isolated as a green solid in 77% yield,
according to Scheme 1. The bis-solvento complex 2 is notable
not only because it is a rare example of a hydride-allenylidene
compound but also due to its cationic nature.
Because in the presence of strong bases the BF4- anion shows
a high trend to decompose releasing fluoride, the preparation
of 2 requires the previously mentioned specific reaction condi-
t
tions. When the treatment of 1 with BuOK is carried out in
dichloromethane at room temperature, instead of acetonitrile at
-30 °C, the hydride-fluoro-alkenylcarbyne derivative [OsHF-
(tCCHdCPh2)(CH3CN)(PiPr3)2]BF4 (4) is obtained as a brown
Figure 1 shows a view of the geometry of the cation of 2.
The coordination around the osmium atom can be rationalized
as a distorted octahedron with the phosphorus atoms of the
phosphine ligands occupying trans positions (P(1)-Os-P(2) )
167.89(5)°). The perpendicular plane is formed by the aceto-
nitrile molecules cis disposed (N(1)-Os-N(2) ) 85.93(18)°),
(17) (a) Bohanna, C.; Callejas, B.; Edwards, A. J.; Esteruelas, M. A.; Lahoz, F.
J.; Oro, L. A.; Ruiz, N.; Valero, C. Organometallics 1998, 17, 373. (b)
Xia, H. P.; Ng, W. S.; Ye, J. S.; Li, X.-Y.; Wong, W. T.; Lin, Z.; Yang,
C.; Jia, G. Organometallics 1999, 18, 4552. (c) Weberndo¨rfer, B.; Werner,
H. J. Chem. Soc., Dalton Trans. 2002, 1479. (d) Wen, T. B.; Zhou, Z. Y.;
Lo, M. F.; Williams, I. D.; Jia, G. Organometallics 2003, 22, 5217. (e)
Lalrempuia, R.; Yennawar, H.; Mozharivskyj, Y. A.; Kollipara, M. R. J.
Organomet. Chem. 2004, 689, 539.
9
J. AM. CHEM. SOC. VOL. 128, NO. 12, 2006 3967

A R T I C L E S
Bolan˜o et al.
solid in 75% yield (Scheme 1). The formation of 4 seems to be
a result of the replacement of one of the acetonitrile molecules
of the cation of 2 by the fluoride resulting from the partial
-
decomposition of the BF4 anion. In agreement with this, the
addition of 1 equiv of CsF to 1 gives 4.
Complex 4 is also notable. Although there are experimental
evidences suggesting that the fluoro complexes are stable when
π-back-bonding ligands are also present in the coordination
sphere of the metal, the chemistry of these compounds is
relatively unexplored.18 To date, only a few osmium-fluoride
organometallic compounds have been reported, among them the
derivatives OsF(CO)2(NdNPh)(PPh3)2,19 [OsF2(CO)3]4,20 OsF-
(COF)(CO)2(PPh3)2,21 and OsF2(CO)2(PR3)2 (R ) Ph, Cy).22
In general, fluoro-carbyne complexes are very rare,23 as far as
we know, the fluoro-osmium-carbyne compounds previously
described only include [OsHF(tCCH2Ph)(Hpz)(PiPr3)2]BF4
13b
and [OsH{F‚‚‚HONdC(CH3)2}(tCCH2R)(PiPr3)2]BF4 (R ) Ph,
Figure 2. Molecular diagram of the cation of complex [Os{(E)-CHd
CHPh}(dCdCdCPh2)(CH3CN)2(PiPr3)2]BF4 (5). Selected bond distances
(Å) and angles (deg): Os-P(1) 2.4426(7), Os-P(2) 2.4255(7), Os-N(1)
2.122(2), Os-N(2) 2.134(2), Os-C(1) 1.866(3), Os-C(16) 2.053(3), C(1)-
C(2) 1.274(4), C(2)-C(3) 1.351(4), C(16)-C(17) 1.307(4), P(1)-Os-P(2)
178.74(3), N(1)-Os-C(16) 169.33(10), N(2)-Os-C(1) 174.49(10), C(1)-
Os-C(16) 90.84(12), Os-C(1)-C(2) 171.9(2), C(1)-C(2)-C(3) 172.3-
(3), Os-C(16)-C(17) 135.1(3), C(16)-C(17)-C(18) 130.6(3).
t
Cy, Bu).14c Alkenylcarbyne derivatives were unknown.
1
The H NMR spectrum of 4 in dichloromethane-d2 at room
temperature supports the presence of the alkenylcarbyne and
hydride ligands. The most noticeable resonance of the alkenyl-
carbyne group is a singlet at 5.26 ppm, corresponding to the
Câ-H hydrogen atom. The hydride ligand gives rise to a triplet
(JH-P ) 17.4 Hz) of doublets (JH-F ) 10.3 Hz) at -5.65 ppm.
In the 13C{1H} NMR spectrum, the CR resonance of the
alkenylcarbyne group appears 263.3 ppm, as a doublet of triplets
with a C-P coupling constant of 9.9 Hz. The value of the C-F
coupling constant of 129.7 Hz is consistent with the trans
disposition of the alkenylcarbyne and fluoride ligands. The Câ
resonance is observed at 133.8 ppm as a doublet (JC-F ) 9.0
Hz), while the Cγ resonance appears at 161.1 ppm as a singlet.
In the 19F NMR spectrum, the fluoride ligand displays a
multiplet at -298.0 ppm. The 31P{1H}NMR spectrum contains
a doublet at 37.4 ppm with a P-F coupling constant of 44.3
Hz.
Scheme 2
2. Reactions of [OsH(dCdCdCPh2)(CH3CN)2(PiPr3)2]BF4
with Alkynes: Formation and Characterization of Alkenyl-
Allenylidene Derivatives. The bis-solvento complex 2 reacts
in dichloromethane at room temperature with terminal alkynes,
such as phenylacetylene and cyclohexylacetylene, to afford the
alkenyl-allenylidene derivatives [Os{(E)-CHdCHR}(dCdCd
CPh2)(CH3CN)2(PiPr3)2]BF4 (R ) Ph (5), Cy (6)), as a result
of the insertion of the carbon-carbon triple bond of the alkynes
into the Os-H bond of 2. Complexes 5 and 6 are isolated as
orange solids in high yield, 93% (5) and 89% (6), according to
Scheme 2.
178.74(3)°). The perpendicular plane is formed by the alkenyl
and the allenylidene ligands cis disposed (C(1)-Os-C(16) )
90.84(12)°) and the two acetonitrile molecules. The alkenyl
ligand is trans disposed to N(1) (N(1)-Os-C(16) ) 169.33-
(10)°), while the allenylidene group is trans disposed to N(2)
(N(2)-Os-C(1) ) 174.49(10)°).
The alkenyl ligand shows an E stereochemistry at the C(16)-
C(17) double bond. The Os-C(16) bond length of 2.053(3) Å
compares well with the Os-C(sp2) single bond distances found
in other osmium-alkenyl complexes,8b,e,24 whereas the C(16)-
C(17) distance of 1.307(4) Å agrees well with the average
Figure 2 shows a view of the geometry of the cation of 5.
The coordination around the osmium atom can be rationalized
as a distorted octahedron with the phosphorus atoms of the
phosphine ligands occupying trans positions (P(1)-Os-P(2) )
(18) Doherty, N. M.; Hoffman, N. W. Chem. ReV. 1991, 91, 553.
(19) Haymore, B. L.; Ibers, J. A. Inorg. Chem. 1975, 14, 2784.
(20) Brewer, S. A.; Holloway, J. H.; Hope, E. G. J. Chem. Soc., Dalton Trans.
1994, 1067.
(21) Brewer, S. A.; Coleman, K. S.; Facett, J.; Holloway, J. H.; Hope, E. G.;
Russell, D. R.; Watson, P. G. J. Chem. Soc., Dalton Trans. 1995, 1073.
(22) Coleman, K. S.; Fawcett, J.; Holloway, J. H.; Hope, E. G.; Russell, D. R.
J. Chem. Soc., Dalton Trans. 1997, 3557.
(23) (a) Birdwhistell, K. R.; Tonker, T. L.; Templeton, J. L. J. Am. Chem. Soc.
1985, 107, 4474. (b) Lemos, M. A. N. D. A.; Pombeiro, A. J. L.; Hughes,
D. L.; Richards, R. L. J. Organomet. Chem. 1992, 434, 66. (c) Hills, A.;
Hughes, D. L.; Kashet, N.; Lemos, M. A. N. D. A.; Pombeiro, A. J. L.;
Richards, R. L. J. Chem. Soc., Dalton Trans. 1992, 1755. (d) Almeida, S.
S. P. R.; Pombeiro, A. J. L. Organometallics 1997, 16, 4469.
(24) See for example: (a) Werner, H.; Esteruelas, M. A.; Otto, H. Organome-
tallics 1986, 5, 2296. (b) Werner, H.; Weinand, R.; Otto, H. J. Organomet.
Chem. 1986, 307, 49. (c) Espuelas, J.; Esteruelas, M. A.; Lahoz, F. J.;
Oro, L. A.; Valero, C. Organometallics 1993, 12, 663. (d) Buil, M. L.;
Esteruelas, M. A.; Lo´pez, A. M.; On˜ate, E. Organometallics 1997, 16, 3169.
(e) Barrio, P.; Esteruelas, M. A.; On˜ate, E. J. Am. Chem. Soc. 2004, 126,
1946. (f) Barrio, P.; Esteruelas, M. A.; On˜ate, E. Organometallics 2004,
23, 3627. (g) Eguillor, B.; Esteruelas, M. A.; Oliva´n, M.; On˜ate, E.
Organometallics 2005, 24, 1428.
9
3968 J. AM. CHEM. SOC. VOL. 128, NO. 12, 2006

Formation of Osmacyclopentapyrrole Derivatives
A R T I C L E S
carbon-carbon double bond distance (1.32(1) Å).25 In ac-
cordance with the sp2 hybridization at C(16) and C(17), the Os-
C(16)-C(17) and C(16)-C(17)-C(18) angles are 135.1(3) and
130.6(3)°, respectively.
Like in 2, the allenylidene ligand is bonded to the metal in a
nearly linear fashion. In this case, the Os-C(1)-C(2) and C(1)-
C(2)-C(3) angles are 171.9(2) and 172.3(3)°, respectively. The
Os-C(1), C(1)-C(2), and C(2)-C(3) distances of 1.866(3),
1.274(4), and 1.351(4) Å, respectively, are statistically identical
with the related bond lengths in 2.
In agreement with the presence of the allenylidene ligands,
the IR spectra of 5 and 6 in Nujol show the characteristic ν-
(CdCdC) bands for this type of ligands at 1899 (5) and 1885
(6) cm-1. In the 1H NMR spectra in dichloromethane-d2 at room
temperature, the vinylic CR-H resonances of the alkenyl ligands
are observed at 10.33 (5) and 8.84 (6) ppm, while the vinylic
Câ-H resonances appear at 6.08 (5) and 4.81 (6) ppm. In
accordance with the E stereochemistry at the carbon-carbon
double bonds, the values of the H-H coupling constants
between the vinylic protons are 16.8 (5) and 16.5 (6) Hz.
Characteristic resonances of the allenylidene ligands in the 13C-
{1H} NMR spectra are triplets at 272.4 (5) and 268.4(6), and
250.8 (5) and 252.9 (6) ppm, with C-P coupling constants of
13.3 (5) and 13.1 (6), and 3.0 (5) and 6.2 (6) Hz, corresponding
to the CR and Câ atoms, respectively, and singlets at 145.2 (5)
and 142.2 (6) ppm due to the Cγ atoms. The alkenyl ligands
display triplets at 132.4 (5) and 121.0 (6) ppm, with C-P
coupling constants of 10.0 (5) and 9.5 (6) Hz, assigned to the
CR atoms, and singlets at 137.4 (5) and 142.5 (6) ppm for the
Câ atoms. The 31P{1H} NMR spectra contain singlets at -9.4
(5) and -12.0 (6) ppm.
In agreement with the structure proposed in Scheme 2, in
the 1H NMR spectrum of 7 in dichloromethane at -20 °C, the
resonance corresponding to the protons of the alkyne appears
at 10.51 ppm as the AA′ part of an AA′XX′ spin system. The
hydride ligand gives rise to a triplet (JH-P ) 22.8 Hz) at -5.05
ppm. In accordance with the chemical shifts found for other
complexes where the alkynes also act as four-electron donor
ligands,26,27,29 the acetylenic resonance in the 13C{1H} NMR
spectrum is observed at 146.6 ppm as a triplet (JC-P ) 3.1 Hz).
Characteristic resonances of the allenylidene ligand are two
triplets at 236.7 (JC-P ) 16.2 Hz) and 208.8 ppm (JC-P ) 6.0
Hz) corresponding to the CR and Câ atoms, respectively, and a
singlet at 137.0 ppm due to the Cγ atom. The 31P{1H} NMR
spectrum shows a singlet at 37.6 ppm.
The difference in behavior between the substituted alkynes
and acetylene merits further comment. The insertion of the C-C
triple bond of an alkyne into the Os-H bond of 2 requires that
the C-C triple bond, the metal center, and the hydride ligand
lie in the same plane. This occurs when the four-electron donor
π-alkyne ligand, with the C-C triple bond parallel disposed to
the P-Os-P direction, rotates 90° and it is converted into a
two-electron donor ligand.27 The steric hindrance experienced
between the substituent of phenylacetylene or cyclohexylacety-
lene and the phosphines in the four-electron donor disposition
(triple bond parallel to the P-Os-P direction) favors the rotation
of these alkynes and, therefore, the insertion of the C-C triple
bond into the Os-H bond. In this context, it should be noted
that, in contrast to the related phenylacetylene and cyclohexyl-
acetylene derivatives, complex [OsH(dCdCH2)(η2-HCtCH)-
(PiPr3)2]BF4 has been isolated at room temperature and char-
acterized by X-ray diffraction analysis.26
3. Alkenyl-Allenylidene-Acetonitrile Coupling: Forma-
tion and Characterization of Osmacyclopentapyrrole De-
rivatives. In acetonitrile under reflux, the alkenyl-allenylidene
complexes 5 and 6 are converted into the osmacyclopentapyrrole
Complex 2 also reacts with acetylene. However, there are
marked differences in behavior between the latter and the
monosubstituted alkynes. In contrast to phenylacetylene and
cyclohexylacetylene, the reaction of 2 with acetylene in dichlo-
romethane at room temperature leads to an ill-defined straw-
colored solid. In acetonitrile, the decomposition does not take
place, but 2 is recovered unaltered. Under acetylene at -20 °C,
the dichloromethane solutions of 2 afford the hydride-
π-alkyne-allenylidene derivative [OsH(dCdCdCPh2)(η2-
HCtCH)(PiPr3)2]BF4 (7), which is isolated at -20 °C as a
brown solid in 94% yield.
derivatives [Os{CdC(CPh2CRdCH)CMedNH}(CH3CN)2-
(PiPr3)2]BF4 (R ) Ph (8), Cy (9)) as a result of a triple carbon-
carbon coupling involving the alkenyl and allenylidene ligands
and an acetonitrile molecule. Complexes 8 and 9 are isolated
as dark red (8) or brown (9) solids in high yield, 83 (8) and
79% (9), according to eq 1.
Complex 7 is the first member of the novel [OsH{dC-
(dC)ndCRR′}(η2-HCtCR′′)(PiPr3)]+ series with n > 0.26 The
NMR spectra of 7 strongly support the presence in the
compound of a π-acetylene group acting as a four-electron donor
ligand.27 Furthermore, they indicate that its structure is like that
of [OsH(dCdCHR)(η2-HCtCH)(PiPr3)2]+, which, on the basis
of an X-ray diffraction study on [OsH(dCdCH2)(η2-HCtCH)-
(PiPr3)2]BF4, has been described as a trigonal bipyramid with
apical phosphines and inequivalent angles within the equatorial
plane.26 In this context, it should be noted that for five-coordinate
complexes an L ligand with σ- and π-donating capabilities
stabilizes the trigonal bipyramid, with the L ligand in the foot
of the Y.28
Figure 3 shows a view of the geometry of the cation of 8.
The structure proves the assembly of the three organic fragments
to form a 1-osma-4-hydrocyclopenta[c]pyrrole skeleton, where
the coordination around the metal center can be described as a
distorted octahedron with the phosphorus atoms of the phosphine
(25) Orpen, A. F.; Brammer, L.; Allen, F. H.; Kennard, O.; Watson, D. G.;
Taylor, R. J. Chem. Soc., Dalton Trans. 1981, 51.
(26) Barrio, P.; Esteruelas, M. A.; On˜ate, E. Organometallics 2003, 22, 2472.
(27) Carbo´, J. J.; Crochet, P.; Esteruelas, M. A.; Jean, Y.; Lledo´s, A.; Lo´pez,
A. M.; On˜ate, E. Organometallics 2002, 21, 305.
(28) Riel, J.-F.; Jean, Y.; Eisenstein, O.; Pe´lissier, M. Organometallics 1992,
11, 729.
(29) See for example: (a) Templeton, J. L. AdV. Organomet. Chem. 1989, 19,
1 and references therein. (b) Baker, P. K. AdV. Organomet. Chem. 1996,
40, 45 and references therein. (c) Frohnapfel, D. S.; Reinartz, S.; White,
P. S.; Templeton, J. L. Organometallics 1998, 17, 3759. (d) Frohnapfel,
D. S.; Enriquez, A. E.; Templeton, J. L. Organometallics 2000, 19, 221.
9
J. AM. CHEM. SOC. VOL. 128, NO. 12, 2006 3969

A R T I C L E S
Bolan˜o et al.
The IR spectra of 8 and 9 in Nujol are consistent with the
presence of an osmahydrocyclopentapyrrole skeleton in these
compounds. Thus, they show ν(N-H) bands at 3318 (8) and
1
3322 (9) cm-1. In the H NMR spectra in dichloromethane-d2
at room temperature, the NH resonances are observed at 7.97
(8) and 7.60 (9) ppm, as broad signals, whereas the C(18)-H
resonances of the fused C5-ring appear at 7.60 (8) and 6.95 (9)
ppm as singlets. The 13C{1H} NMR spectra also support a low
degree of electronic delocalization in the OsNC3-ring. Thus, the
OsC(1) resonances appear at 204.2 (8) and 209.7 (9) ppm, as
triplets with C-P coupling constants of 7.0 (8) and 5.3 (9) Hz.
These resonances are shifted about 10 ppm toward lower
field with regard to the chemical shifts observed for the
hydride-osmium(IV) complexes [OsH(η5-C5H5){NHdC(p-
C6H4R)CHdC(CH3)](PHiPr2)]BF4 (R ) CH3, H, Cl), and about
20 ppm toward higher field with regard to the chemical shifts
observed for the corresponding deprotonated osmium(II) deriva-
tives, where, in contrast to the hydride-osmium(IV) precursors,
aromaticity has been invoked in order to describe the bonding
situation in the five-membered heterometallaring.30 On the basis
of the APT, HMBC, and the HSQC spectra, singlets at 176.3
(8) and 175.9 (9), 159.6 (8) and 168.6 (9), 156.7 (8) and 149.7
(9), 140.0 (8) and 135.9 (9), and 69.5 (8) and 70.6 (9) ppm are
assigned to the C(3), C(19), C(2), C(18), and C(5) atoms,
respectively. The 31P{1H} NMR spectra contains singlets at -6.1
(8) and -5.0 (9) ppm.
Reactions involving one nitrile and unsaturated organic
fragments have provided convenient routes to interesting
metallacyclic imines.33 In this context, we note that Buchwald
and co-workers have reported a wide series of nitrile coupling
reactions with zirconocene precursors to form azametallacycles
with extremely good regiochemical control.34 However, as far
as we know, couplings involving one nitrile and two different
organic fragments, like that shown in eq 1, have not been
previously reported.
Figure 3. Molecular diagram of the cation of complex [Os{CdC(CPh2-
CPhdCH)CMedNH}(CH3CN)2(PiPr3)2]BF4 (8). Selected bond distances
(Å) and angles (deg): Os-P(1) 2.4149(16), Os-P(2) 2.3921(16), Os-N(1)
2.044(5), Os-N(2) 1.974(5), Os-C(1) 1.996(6), Os-N(3) 2.084(5), C(1)-
C(2) 1.386(8), C(2)-C(3) 1.422(8), C(3)-N(1) 1.316(7), C(18)-C(19)
1.344(8), C(1)-C(18) 1.473(8), C(5)-C(19) 1.560(8), C(2)-C(5) 1.545-
(7), P(1)-Os-P(2) 170.76(6), N(1)-Os-N(2) 171.1(2), N(1)-Os-C(1)
76.4(2), N(3)-Os-C(1) 164.3(2), Os-N(1)-C(3) 119.5(4), Os-C(1)-
C(2) 117.0(4), C(1)-C(2)-C(3) 114.6(5), C(2)-C(3)-N(1) 112.4(6).
ligands occupying trans positions (P(1)-Os-P(2) ) 170.76-
(6)°). The perpendicular plane is formed by the chelate group,
which acts with a bite angle N(1)-Os-C(1) of 76.4(2)°, and
the acetonitrile molecules with N(2) disposed trans to N(1)
(N(1)-Os-N(2) ) 171.1(2)°) and N(3) disposed trans to C(1)
(N(3)-Os-C(1) ) 164.3(2)°).
The osmahydrocyclopentapyrrole skeleton is almost planar.
The deviations (in Å) from the best plane are 0.022(3) (Os),
-0.033(5) (C(1)), -0.010(5) (C(18)), 0.013(5) (C(19)), 0.037-
(4) (C(5)), -0.028(5) (C(2)), -0.030(4) (C(3)), and 0.030(4)
(N(1)). The imine group is bonded to the osmium atom with
an Os-N(1)-C(3) angle of 119.5(4)°. The Os-N(1) (2.044(5)
Å), C(3)-N(1) (1.316(7) Å), C(2)-C(3) (1.422(8) Å), and
C(1)-C(2) (1.386(8) Å) bond lengths are statistically identical
The formation of the osmabicycles of 8 and 9 can be
rationalized according to Scheme 3. The migratory insertion of
the allenylidene ligands of 5 and 6 into the Os-alkenyl bonds
should give allenyl species a, which by coordination of an
acetonitrile molecule could afford the intermediates b related
to complex 3. Nitriles exhibit electrophilic reactivity at the C(sp)
atom,35 by virtue of the contribution of a dipolar resonance form
with the related distances in the complex [OsH(η5-C5H5){NHd
30
C(p-C6H4Cl)CHdC(CH3)}(PHiPr2)]BF4 and indicate a low
degree of electronic delocalization in the azametallacyclopen-
tadienyl ring. This agrees well with that observed for tung-
stenapyrrole compounds by Legzdins and co-workers.31 How-
ever, it is in contrast with the aromaticity invoked by Carmona’s
group for iridapyrrole derivatives.32 In accordance with a low
contribution of the carbene resonance form to the osmium-
carbon bond, the Os-C(1) distance of 1.996(6) Å is only about
0.03 Å shorter than the Os-C(16) bond length in 5. The C(18)-
C(19) distance of 1.344(8) Å strongly supports the presence of
a double bond between these atoms of the fused C5-ring.
(33) (a) Cohen, S. A.; Bercaw, J. E. Organometallics 1985, 4, 1006. (b) Erker,
G.; Pfaff, R. Organometallics 1993, 12, 1921. (c) Maeyama, T.; Mikami,
N. J. Am. Chem. Soc. 1988, 110, 7238. (d) Bennett, M.; Schwemlein, H.
P. Angew. Chem., Int. Ed. Engl. 1989, 28, 1296. (e) Doxsee, K. M.; Mouser,
J. K. M. Organometallics 1990, 9, 3012. (f) Curtis, M. D.; Real, J.; Hirpo,
W.; Butler, W. M. Organometallics 1990, 9, 66. (g) Filippou, A. C.; Vo¨lkl,
C.; Kiprof, P. J. Organomet. Chem. 1991, 415, 375. (h) Erker, G.; Pfaff,
R.; Kru¨ger, C.; Nolte, M.; Goddard, R. Chem. Ber. 1992, 125, 1669. (i)
Guram, A. S.; Jordan F. J. J. Org. Chem. 1993, 58, 5595. (j) Michelin, R.
A.; Mozzon, M.; Bertani, R. Coord. Chem. ReV. 1996, 147, 299. (k) Busetto,
L.; Camiletti, C.; Zanotti, V.; Albano, V. G.; Sabatino, P. J. Organomet.
Chem. 2000, 593-594, 335. (l) Kukushkin, V. Y.; Pombeiro, A. J. L. Chem.
ReV. 2002, 102, 1771.
(34) (a) Buchwald, S. L.; Watson, B. T. J. Am. Chem. Soc. 1986, 108, 7411.
(b) Buchwald, S. L.; Lum, R. T.; Dewan, J. C. J. Am. Chem. Soc. 1986,
108, 7441. (c) Buchwald, S. L.; Watson, B. T. J. Am. Chem. Soc. 1987,
109, 2544. (d) Buchwald, S. L.; Watson, B. T.; Lum, R. T.; Nugent, W. A.
J. Am. Chem. Soc. 1987, 109, 7137. (e) Buchwald, S. L.; Nielsen, R. B.;
Dewan, J. C. J. Am. Chem. Soc. 1987, 109, 1590. (f) Buchwald, S. L.;
Sayers, A.; Watson, B. T.; Dewan, J. C. Tetrahedron Lett. 1987, 28, 3245.
(g) Buchwald, S. L.; Nielsen, R. B. Chem. ReV. 1988, 88, 1047. (h)
Buchwald, S. L.; Watson, B. T.; Wannamaker, M. W.; Dewan, J. C. J.
Am. Chem. Soc. 1989, 111, 4486. (i) Fisher, R. A.; Buchwald, S. L.
Organometallics 1990, 9, 871. (j) Buchwald, S. L.; King, S. M. J. Am.
Chem. Soc. 1991, 113, 258.
(30) Baya, M.; Esteruelas, M. A.; Gonza´lez, A. I.; Lo´pez, A. M.; On˜ate, E.
Organometallics 2005, 24, 1225.
(31) (a) Legzdins, P.; Lumb, S. A. Organometallics 1997, 16, 1825. (b) Legzdins,
P.; Lumb, S. A.; Young, V. G., Jr. Organometallics 1998, 17, 854.
(32) (a) Alvarado, Y.; Daff, P. J.; Pe´rez, P. J.; Poveda, M. L.; Sa´nchez-Delgado,
R.; Carmona, E. Organometallics 1996, 15, 2192. (b) Alia´s, F. M.; Poveda,
M. L.; Sellin, M.; Carmona, E.; Gutie´rrez-Puebla, E.; Monge, A. Orga-
nometallics 1998, 17, 4124. (c) Alias, 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.sEur. J. 2002, 8, 5132.
9
3970 J. AM. CHEM. SOC. VOL. 128, NO. 12, 2006

Formation of Osmacyclopentapyrrole Derivatives
A R T I C L E S
Scheme 3
carbon atoms of the cumulene. The CR and Cγ atoms of the
allenylidene ligand are coupled with the CR and Câ atoms,
respectively, of the alkenyl group, while the Câ atom of the
allenylidene is added to the C(sp) atom of an acetonitrile
molecule.
In conclusion, metallacyclopentapyrrole derivatives can be
formed by assembling an allenylidene ligand with an alkyne
and a nitrile, via hydride-allenylidene and alkenyl-allenylidene
intermediates.
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. The starting material [OsH(t
CCHdCPh2)(CH3CN)2(PiPr3)2][BF4]2 (1) was prepared by the published
method.16 1H, 31P{1H}, and 13C{1H} NMR spectra were recorded on
either 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 H3-
PO4 (31P{1H}). Coupling constants, J and N, 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-nitroben-
zyl alcohol (NBA) was used in the matrix.
Preparation of [OsH(dCdCdCPh2)(CH3CN)2(PiPr3)2]BF4 (2). A
red solution of 1 (500 mg, 0.522 mmol) in 12 mL of acetonitrile at
-30 °C was treated with tBuOK (88 mg, 0.782 mmol), and the mixture
was stirred for 4 h until reaching room temperature. Then, the
suspension was filtered through Celite, and the filtrate was evaporated.
The addition of diethyl ether afforded a green solid, which was washed
with a mixture of diethyl ether/pentane (1:3) and dried in vacuo.
Yield: 350 mg (77%). Anal. Calcd for C37H59BF4N2OsP2: C 51.03; H
6.83; N 3.21. Found: C 50.53; H 6.50; N 2.99. IR (Nujol, cm-1):
ν(CtN) 2325 (w); ν(OsH) 2129 (m); ν(CdCdC) 1886 (s); ν(BF) 1058
(vs). MS: m/z 723 [M + HF]+. 1H NMR (300 MHz, CD2Cl2, 293 K):
δ 7.73 (tt, JH-H ) 7.5 and 1.2, 2H, p-Ph), 7.64 (d, JH-H ) 7.2, 4H,
o-Ph), 7.31 (dd, JH-H ) 7.5 and 7.2, 4H, m-Ph), 3.01 and 2.77 (both s,
6H, CH3CN), 2.40 (m, 6H, PCH), 1.19 (dvt, N ) 13.2, JH-H ) 7.2,
18H, PCHCH3), 1.15 (dvt, N ) 14.5, JH-H ) 7.3, 18H, PCHCH3),
-10.66 (t, JP-H ) 17.5, 1H, OsH). 31P{1H} NMR (121.4 MHz, CD2-
Cl2, 293 K): δ 11.8 (s). 19F NMR (282.3 MHz, CD2Cl2, 293 K): δ
-152.7 (br). 13C{1H}-APT NMR plus HMBC and HSQC (75.4 MHz,
to the carbon-nitrogen triple bond. Thus, the electrophilic attack
of the C(sp) atom of acetonitrile to the Câ atom of the cumulene
should lead to c. This attack is consistent with EHT-MO
calculations showing the nucleophilic character of the Câ atom
in these types of cumulenes.5 The ring-closure of c should give
d, which could generate 8 and 9 by dissociation of the RCH-
hydrogen atom as H+ and subsequent protonation of the nitrogen
atom. In agreement with this, we have observed that, in the
presence of D2O, the formation of 8 takes place with the
deuteration of the nitrogen atom, while the addition of D2O to
an acetonitrile solution of 8 does not give to the deuteration of
the heteroatom.
Concluding Remarks
This study shows, step by step, the formation of osmacyclo-
pentapyrrole derivatives, starting from a dicationic bis-solvento
hydride-alkenylcarbyne compound, terminal alkynes, and
acetonitrile.
The selective deprotonation of the alkenyl substituent of the
alkenylcarbyne group of the hydride complex [OsH(tCCHd
CPh2)(CH3CN)2(PiPr3)2][BF4]2 affords the novel hydride-
allenylidene derivative [OsH(dCdCdCPh2)(CH3CN)2(PiPr3)2]-
BF4, which is the key species to assemble the organic fragments,
in a LEGO manner, until the osmabicycles are obtained.
The hydride ligand of this cumulene compound is an efficient
anchor to nail terminal alkynes beside the allenylidene ligand.
Thus, it reacts with phenylacetylene and cyclohexylacetylene
to give the alkenyl-allenylidene derivatives [Os{(E)-
CHdCHR}(dCdCdCPh2)(CH3CN)2(PiPr3)2]BF4 (R ) Ph,
CD2Cl2, 293 K): δ 267.8 (t, JC-P ) 13.4, OsdC), 252.2 (t, JC-P
)
8.1, dCd), 154.2 (s, Cipso-Ph), 142.3 and 131.9 (both s, CN), 137.5
(s, dCPh2), 129.2 (s, m-Ph), 128.0 (s, p-Ph) and 126.2 (s, o-Ph), 25.5
(vt, N ) 12.3, PCH), 19.0 and 18.7 (both s, PCHCH3), 3.8 (s, CH3-
CN).
Preparation of [Os(CHdCdCPh2)(CH3CN)2(CO)(PiPr3)2]BF4 (3).
A green solution of 2 (220 mg, 0.253 mmol) in 8 mL of dichlo-
romethane was stirred under carbon monoxide atmosphere. Im-
mediately, the reaction mixture became red. After 15 min, the solution
was filtered through Celite, and the solvent was removed in vacuo.
The residue was washed with diethyl ether to afford a red solid. Yield:
195 mg (86%). Anal. Calcd for C38H59BF4N2OOsP2: C 50.77; H 6.61;
N 3.11. Found: C 50.53; H 6.28; N 2.98. IR (Nujol, cm-1): ν(CtN)
2328 (w); ν(CtO) 1927 (s); ν(BF) 1058 (vs). MS: m/z 731 [M -
Cy), which in acetonitrile are converted into [Os{CdC(CPh2-
CRdCH)CMedNH}(CH3CN)2(PiPr3)2]BF4 by means of the
formation of three carbon-carbon bonds involving the three
1
2CH3CN]+. H NMR (300 MHz, CD2Cl2, 293 K): δ 7.30-7.14 (m,
10H, Ph), 7.06 (t, JH-P ) 2.4, OsCH), 2.56 and 2.51 (both s, 6H, CH3-
CN), 2.56 (m, 6H, PCH), 1.26 (dvt, N ) 22.3, JH-H ) 6.7, 18H,
PCHCH3), 1.23 (dvt, N ) 22.5, JH-H ) 6.9, 18H, PCHCH3). 31P{1H}
NMR (121.4 MHz, CD2Cl2, 293 K): δ 3.7 (s). 19F NMR (282.3 MHz,
CD2Cl2, 293 K): δ -152.1 (br). 13C{1H}-APT NMR plus HMBC and
HSQC (75.4 MHz, CD2Cl2, 293 K): δ 206.1 (t, JC-P ) 2.6, dC)),
(35) See for example: (a) Feng, S. G.; Templeton, J. L. Organometallics 1992,
11, 1295. (b) Feng, S. G.; White, P. S.; Templeton, J. L. Organometallics
1993, 12, 1765. (c) Feng, S. G.; White, P. S.; Templeton, J. L. J. Am.
Chem. Soc. 1994, 116, 8613. (d) Gunnoe, T. B.; White, P. S.; Templeton,
J. L. J. Am. Chem. Soc. 1996, 118, 6916. (e) Vogeley, N. J.; Templeton,
J. L. Polyhedron 2004, 23, 311. (f) Cross, J. L.; Garrett, A. D.; Crane, T.
W.; White, P. S.; Templeton, J. L. Polyhedron 2004, 23, 2831.
9
J. AM. CHEM. SOC. VOL. 128, NO. 12, 2006 3971

A R T I C L E S
Bolan˜o et al.
1
183.5 (t, JC-P ) 9.8, CtO), 139.8 (s, Cipso-Ph), 101.0 (s, dCPh2),
125.6 and 125.4 (both s, CN), 128.4, 128.0 and 125.6 (all s, CHPh),
69.1 (t, JC-P ) 7.7, OsCH), 25.3 (vt, N ) 12.2, PCH), 19.0 and 18.8
(both s, PCHCH3), 4.1 and 3.4 (s, CH3CN).
CN - PiPr3]+. H NMR (300 MHz, CD2Cl2, 293 K): δ 8.84 (d, JH-H
) 16.5, 1H, OsCH), 7.75-7.73 (m, 6H, o-Ph and p-Ph), 7.24 (dd, JH-H
) 7.5 and 7.2, 4H, m-Ph), 4.81 (dd, JH-H ) 16.5 and 6.7, 1H, dCHCy),
3.15 and 2.85 (both s, 6H, CH3CN), 2.55 (m, 6H, PCH), 1.8-0.8 (m,
11H, Cy), 1.18 (dvt, N ) 12.9, JH-H ) 7.2, 18H, PCHCH3), 1.16 (dvt,
N ) 14.2, JH-H ) 7.3, 18H, PCHCH3). 31P{1H} NMR (121.4 MHz,
CD2Cl2, 293 K): δ -12.0 (s). 19F NMR (282.3 MHz, CD2Cl2, 293 K):
δ -152.4 (br). 13C{1H}-APT NMR plus HMBC and HSQC (100.5
MHz, CD2Cl2, 293 K): δ 268.4 (t, JC-P ) 13.1, OsdC), 252.9 (t, JC-P
) 6.2, dCd), 154.1 (s, Cipso-Ph), 142.6 and 132.3 (both s, CN), 142.5
(s, dCHCy), 142.2 (s, dCPh2), 129.0 (s, m-Ph), 128.5 (s, p-Ph) and
127.0 (s, o-Ph), 121.0 (t, JC-P ) 9.5, OsCH), 46.7 (s, CHCy), 34.4,
26.7, and 26.6 (all s, CH2), 23.6 (vt, N ) 11.7, PCH), 18.9 and 18.7
(both s, PCHCH3), 4.6 and 3.8 (both s, CH3CN).
Preparation of [OsHF(tCCHdCPh2)(CH3CN)(PiPr3)2]BF4 (4).
Method a: A red solution of 1 (150 mg, 0.156 mmol) in 7 mL of
dichloromethane was treated with tBuOK (26 mg, 0.235 mmol). After
stirring the mixture for 5 h at room temperature, the suspension was
filtered through Celite, and the filtrate was evaporated. The addition
of diethyl ether gave rise to the formation of a brown solid, which was
washed with diethyl ether and dried in vacuo. Yield: 100 mg (75%).
Method b: A red solution of 1 (120 mg, 0.125 mmol) in 7 mL of
dichloromethane was treated with CsF (19 mg, 0.125 mmol). After
stirring the mixture for 2 h at room temperature, the suspension was
filtered through Celite, and the filtrate was evaporated. The addition
of diethyl ether gave rise to the formation of a brown solid, which was
washed with diethyl ether and dried in vacuo. Yield: 95 mg (79%).
Anal. Calcd for C35H57BF5NOsP2: C 49.47; H 6.76; N 1.65. Found:
C 48.99; H 6.51; N 1.50. IR (Nujol, cm-1): ν(CtN) 2330 (w); ν(OsH)
2168 (m); ν(CdC) 1535 (m); ν(BF) 1061 (vs). MS: m/z 723 [M -
Preparation of [OsH(dCdCdCPh2)(η2-HCtCH)(PiPr3)2]BF4
(7). A green solution of 2 (250 mg, 0.287 mmol) in 7 mL of
dichloromethane at 253 K was stirred under acetylene atmosphere. After
3 h at 253 K, the resulting mixture was concentrated. The addition of
diethyl ether at 253 K gave rise to the formation of a brown solid,
which was washed with diethyl ether and dried in vacuo. Yield: 219
mg (94%). Anal. Calcd for C35H53BF4OsP2: C 51.72; H 6.57. Found:
C 51.35; H 6.75. IR (Nujol, cm-1): ν(OsH) 2115 (w); ν(CdCdC)
1919 (s); ν(BF) 1061 (vs). MS: m/z 701 [M - C2H2]+. 1H NMR (300
MHz, CD2Cl2, 253 K): δ 10.51 (part AA′ of an AA′XX′ spin system,
AA′ ) H2C2 and XX′ ) (PiPr3)2), 7.61 (t, JH-H ) 7.0, 2H, p-Ph), 7.38
(d, JH-H ) 7.3, 4H, o-Ph), 7.30 (dd, JH-H ) 7.3 and 7.0, 4H, m-Ph),
2.88 (m, 6H, PCH), 1.19 (dvt, N ) 13.5, JH-H ) 6.9, 18H, PCHCH3),
1
CH3CN]+. H NMR (300 MHz, CD2Cl2, 293 K): δ 7.78-7.21 (m,
10H, Ph), 5.26 (s, 1H, dCH-), 2.68 (s, 3H, CH3CN), 2.48 (m, 6H,
PCH), 1.31 (dvt, N ) 13.8, JH-H ) 7.0, 36H, PCHCH3), -5.65 (td,
JH-P ) 17.4, JH-F ) 10.3, 1H, OsH). 31P{1H} NMR (121.4 MHz, CD2-
Cl2, 293 K): δ 37.4 (d, JP-F ) 44.3). 19F NMR (282.3 MHz, CD2Cl2,
293 K): δ -151.6 (br, BF4), -298.0 (m, Os-F). 13C{1H}-APT NMR
plus HMBC and HSQC (75.4 MHz, CD2Cl2, 293 K): δ 263.3 (dt, JC-F
) 129.7, JC-P ) 9.9, OstC), 161.1 (s, dCPh2), 139.1 and 139.0 (both
s, Cipso-Ph), 133.8 (d, JC-F ) 9.0, -CHd), 131.5, 131.4, 130.5, 129.3,
129.1 and 128.5 (all s, CHPh), 129.0 (s, CN), 25.5 (vt, N ) 13.0, PCH),
19.2 and 18.9 (both s, PCHCH3), 3.7 (s, CH3CN).
1.10 (dvt, N ) 14.2, JH-H ) 6.8, 18H, PCHCH3), -5.05 (t, JH-P
)
22.8, 1H, OsH). 31P{1H} NMR (121.4 MHz, CD2Cl2, 253 K): δ 37.6
(s). 19F NMR (282.3 MHz, CD2Cl2, 253 K): δ -152.8 (br). 13C{1H}-
APT NMR plus HMBC and HSQC (75.4 MHz, CD2Cl2, 253 K): δ
236.7 (t, JC-P ) 16.2, OsdC), 208.8 (t, JC-P ) 6.0, dCd), 146.6 (t,
JC-P ) 3.1, H2C2), 143.4 (s, Cipso-Ph), 137.0, (s, dCPh2), 129.4 (s,
p-Ph), 129.0 (s, m-Ph) and 127.3 (s, o-Ph), 24.6 (vt, N ) 14.6, PCH),
20.4 and 19.1 (both s, PCHCH3).
Preparation of [Os{(E)-CHdCHPh}(dCdC)CPh2)(CH3CN)2-
(PiPr3)2]BF4 (5). A green solution of 2 (288 mg, 0.331 mmol) in 10
mL of dichloromethane was treated with phenylacetylene (37 µL, 0.331
mmol). After the mixture was stirred for 30 min at room temperature,
it was filtered through Celite, and the filtrate was evaporated. The
addition of diethyl ether afforded an orange solid, which was washed
with a mixture of diethyl ether/pentane (1:3) and dried in vacuo.
Yield: 300 mg (93%). Anal. Calcd for C45H65BF4N2OsP2: C 55.55; H
6.73; N 2.88. Found: C 55.46; H 6.28; N 2.81. IR (Nujol, cm-1):
ν(CtN) 2317 (w); ν(CdCdC) 1899 (s); ν(CdC) 1550 (m); ν(BF)
Preparation of [Os{CdC(CPh2CPhdCH)CMedNH}(CH3CN)2-
(PiPr3)2]BF4 (8). An orange solution of 5 (150 mg, 0.154 mmol) in 12
mL of acetonitrile was heated under reflux for 8 h. The solution was
filtered through Celite, and the solvent was removed in vacuo. The
addition of diethyl ether to the resulting residue led to a dark red solid,
which was washed with diethyl ether and dried in vacuo. Yield: 130
mg (83%). Anal. Calcd for C47H68BF4N3OsP2: C 55.67; H 6.76; N
4.14. Found: C 55.54; H 6.24; N 4.32. IR (Nujol, cm-1): ν(NH) 3318
(w); ν(CtN) 2327 (w), 2230 (w); ν(BF) 1059 (vs). MS: m/z 887 [M
- CH3CN]+; 842 [M - 2CH3CN]+. 1H NMR (300 MHz, CD2Cl2, 293
K): δ 7.97 (br, 1H, NH), 7.60 (s, 1H, dCH), 7.33-7.16 (m, 15H,
Ph), 2.77 and 2.64 (both s, 6H, CH3CN), 2.28 (m, 6H, PCH), 2.14 (s,
3H, CH3), 1.30 (dvt, N ) 13.5, JH-H ) 6.9, 18H, PCHCH3), 0.99 (dvt,
N ) 12.4, JH-H ) 6.4, 18H, PCHCH3). 31P{1H} NMR (121.4 MHz,
CD2Cl2, 293 K): δ -6.1 (s). 19F NMR (282.3 MHz, CD2Cl2, 293 K):
δ -152.4 (br). 13C{1H}-APT NMR plus HMBC and HSQC (75.4 MHz,
CD2Cl2, 293 K): δ 204.2 (t, JC-P ) 7.0, C(1)), 176.3 (s, C(3)), 159.6
(s, C(19)), 156.7 (s, C(2)), 140.5 and 136.0 (both s, Cipso-Ph), 140.0
(s, C(18)), 127.5 and 120.8 (both s, CN), 129.3, 128.8, 128.2, 128.1,
127.8, and 126.8 (all s, CHPh), 69.5 (s, C(5)), 24.7 (vt, N ) 11.3, PCH),
22.4 (s, C(4)), 19.6 and 18.7 (both s, PCHCH3), 4.7 and 4.0 (both s,
CH3CN).
1059 (vs). MS: m/z 804 [M - 2CH3CN]+; 643 [M - 2CH3CN -
1
PiPr3]+. H NMR (400 MHz, CD2Cl2, 293 K): δ 10.33 (dt, JH-H
)
16.8, JH-P ) 2.0, 1H, OsCHd), 7.82 (d, JH-H ) 7.2, 4H, o-Phallen),
7.76 (t, JH-H ) 7.6, 2H, p-Phallen), 7.31 (dd, JH-H ) 7.6 and 7.2, 4H,
m-Phallen), 7.26 (dd, JH-H ) 7.6 and 7.2, 2H, m-Phvinyl), 7.06 (d JH-H
7.2, 1H, o-Phvinyl), 6.92 (t, JH-H ) 7.6, 2H, p-Phvinyl), 6.08 (d, JH-H
)
)
16.8, 1H, dCHPh), 3.23 and 2.90 (both s, 6H, CH3CN), 2.51 (m, 6H,
PCH), 1.20 (dvt, N ) 12.6, JH-H ) 6.6, 18H, PCHCH3), 1.16 (dvt, N
) 13.0, JH-H ) 6.6, 18H, PCHCH3). 31P{1H} NMR (121.4 MHz, CD2-
Cl2, 293 K): δ -9.4 (s). 19F NMR (282.3 MHz, CD2Cl2, 293 K): δ
-152.2 (br). 13C{1H}-APT NMR plus HMBC and HSQC (100.5 MHz,
CD2Cl2, 293 K): δ 272.4 (t, JC-P ) 13.3, OsdC), 250.8 (t, JC-P
)
3.0, dCd), 154.3 (s, Cipso-Phallen), 145.2 (s, dCPh2), 143.1 and 131.8
(both s, CN), 141.8 (s, Cipso-Phvinyl), 137.4 (s, dCHPh), 132.4 (t, JC-P
) 10.0, OsCH), 129.4 (s, m-Phallen), 129.1 (s, p-Phallen), 128.3 (s,
m-Phvinyl), 127.4 (s, o-Phallen), 124.9 (s, o-Phvinyl), 124.3 (s, p-Phvinyl),
24.5 (vt, N ) 11.6, PCH), 19.4 and 19.3 (both s, PCHCH3), 4.8 and
4.0 (s, CH3CN).
Preparation of [Os{(E)-CHdCHCy}(dCdCdCPh2)(CH3CN)2-
(PiPr3)2]BF4 (6). This complex was prepared as described for 5, starting
from 2 (200 mg, 0.230 mmol) and cyclohexylacetylene (30 µL, 0.23
mmol). An orange solid was obtained. Yield: 200 mg (89%). Anal.
Calcd for C45H71BF4N2OsP2: C 55.2; H 7.31; N 2.86. Found: C 54.80;
H 7.25; N 2.96. IR (Nujol, cm-1): ν(CtN) 2349 (w); ν(CdCdC) 1885
(s); ν(BF) 1060 (vs). MS: m/z 811 [M - 2CH3CN]+; 651 [M - 2CH3-
9
3972 J. AM. CHEM. SOC. VOL. 128, NO. 12, 2006

Formation of Osmacyclopentapyrrole Derivatives
A R T I C L E S
Table 1. Crystal Data and Data Collection and Refinement for 2, 5, and 8
2
5
8
Crystal Data
formula
C37H58BF4N2OsP2
‚CH2Cl2
955.74
C45H65BF4N2OsP2
C47H68BF4N3OsP2
molecular wt
972.94
1013.99
color and habit
size, mm
symmetry, space group
a, Å
b, Å
c, Å
orange, irregular block
0.80, 0.08, 0.06
monoclinic, P21/n
11.5033(12)
33.861(4)
11.8212(13)
red, irregular block
0.20, 0.016, 0.16
triclinic, P1h
7.4633(6)
11.2428(9)
13.7705(11)
84.140(2)
83.248(3)
81.579(2)
2205.4(6)
2
orange, irregular block
0.10, 0.06, 0.06
monoclinic, P21/c
11.3003(14)
10.9934(13)
38.071(5)
R, deg
â, deg
γ, deg
V, Å3
Z
111.056(2)
94.455(2)
4297.1(8)
4
1.477
4715.3(10)
4
1.428
D
calc, g cm-3
1.465
Data Collection and Refinement
diffractometer
λ(Mo KR), Å
monochromator
scan type
Bruker Smart APEX
0.71073
graphite oriented
ω scans
3.013
3, 57
100.0(2)
26188
10513 (Rint ) 0.0284)
518/0
0.0258
0.0508
µ, mm-1
3.212
3, 57
173.0(2)
53716
10629 (Rint ) 0.0870)
458/20
0.0499
0.0892
2.823
3, 57
100.0(2)
41140
11465 (Rint ) 0.0971)
540/39
0.0503
0.0803
2θ, range deg
temp, K
no. of data collect
no. of unique data
no. of params/restrains
R1a [F2 > 2σ(F2)]
wR2b [all data]
Sc [all data]
0.880
0.876
0.784
2
2
2
2
2
a R1(F) ) ∑||Fo| - |Fc||/∑|Fo|. b wR2(F2) ) {∑[w(Fo - Fc )2]/∑[w(Fo )2]}1/2
.
c Gof ) S ) {∑[Fo - Fc )2]/(n - p)}1/2, where n is the number of
reflections, and p is the number of refined parameters.
combination of four sets. Each frame exposure time was 10 or 30 s
covering 0.3° in ω. Data were corrected for absorption by using a
multiscan method applied with the Sadabs36 program. The structures
for all compounds were solved by the Patterson method. Refinement,
by full-matrix least squares on F2 with SHELXL97,37 was similar for
all complexes, including isotropic and subsequently anisotropic dis-
placement parameters for all non-hydrogen atoms. The hydrogen atoms
were observed or calculated and refined freely or using a restricted
riding model, respectively.
For 2, a molecule of dichloromethane was observed in the least cycles
of refinement in the asymmetric cell. This molecule was refined with
restrains in the geometry and thermal parameters. For 8, the BF4- anion
was observed disordered over two sites. These molecules were also
refined with restrains in the their geometry and thermal parameters.
A summary of crystal data and data collection and refinement details
is reported in Table 1.
Preparation of [Os{CdC(CPh2CCydCH)CMedNH}(CH3CN)2-
(PiPr3)2]BF4 (9). This complex was prepared as described for 8, starting
from 120 mg (0.123 mmol) of 6. A brown solid was obtained. Yield:
99 mg (79%). Anal. Calcd for C47H68BF4N3OsP2: C 55.34; H 7.31; N
4.12. Found: C 55.37; H 6.88; N 4.64. IR (Nujol, cm-1): ν(NH) 3322
(w); ν(CtN) 2326 (w), 2239 (w); ν(BF) 1061 (vs). MS: m/z 893 [M
1
- CH3CN]+. H NMR (300 MHz, CD2Cl2, 293 K): δ 7.60 (s, 1H,
NH), 6.95 (s, 1H, dCH), 7.52-7.18 (m, 10H, Ph), 2.73 and 2.60 (both
s, 6H, CH3CN), 2.24 (m, 6H, PCH), 2.14 (s, 3H, CH3), 1.72-1.60 (m,
11H, Cy), 1.24 (dvt, N ) 13.2, JH-H ) 6.6, 18H, PCHCH3), 0.97 (dvt,
N ) 12.4, JH-H ) 6.7, 18H, PCHCH3). 31P{1H} NMR (121.4 MHz,
CD2Cl2, 293 K): δ -5.0 (s). 19F NMR (282.3 MHz, CD2Cl2, 293 K):
δ -152.4 (br). 13C{1H}-APT NMR plus HMBC and HSQC (100.5
MHz, CD2Cl2, 293 K): δ 209.7 (t, JC-P ) 5.3, C(1)), 175.9 (s, C(3)),
168.6 (s, C(19)), 149.7 (s, C(2)), 142.0 (s, Cipso-Ph), 135.9 (s, C(18)),
128.6, 128.0, and 126.4 (all s, CHPh), 127.4 and 120.5 (both s, CN),
70.6 (s, C(5)), 38.2 (s, CHCy), 35.2, 27.2, and 26.6 (all s, CH2), 25.0
(vt, N ) 11.2, PCH), 23.1 (s, C(4)), 20.2 and 19.2 (both s, PCHCH3),
5.2 and 4.5 (both s, CH3CN).
Acknowledgment. Financial support from the MCYT of
Spain (Project CTQ2005-00656) is acknowledged. R.C. thanks
CSIC and the European Social Fund for funding through the
I3P Program. Dedicated to Professor Victor Riera on the
occasion of his 70th birthday.
Supporting Information Available: Crystal structure deter-
minations, including bond lengths and angles of compounds 2,
5, and 8. This material is available free of charge via the Internet
at http://pubs.acs.org.
JA058355B
Structural Analysis of Complexes 2, 5, and 8. X-ray data were
collected for all complexes at low temperature on a Bruker Smart APEX
CCD diffractometer equipped with a normal focus, 2.4 kW sealed tube
source (molybdenum radiation, λ ) 0.71073 Å) operating at 50 kV
and 40 mA. Data were collected over the complete sphere by a
(36) Blessing, R. H. Acta Crystallogr. 1995, A51, 33-38. SADABS: Area-
detector absorption correction, 1996, Bruker-AXS, Madison, WI.
(37) SHELXTL, Package v. 6.10, 2000, Bruker-AXS, Madison, WI. Sheldrick,
G. M. SHELXS-86 and SHELXL-97; University of Go¨ttingen: Go¨ttingen,
Germany, 1997.
9
J. AM. CHEM. SOC. VOL. 128, NO. 12, 2006 3973