Reactivity of [MCl(η3-allyl)(1,10-phenanthroline)(CO)2] (M = Mo, W) complexes toward enolate anions

Article abstract of DOI:10.1021/om030275y

The reactions of the complexes [MCl(η³-C₃H₄-R)(CO)₂(phen)] (1a-c; M = Mo, W) with KCH₂C(O)Ar afford the O-bound enolato complexes [M(η³-C₃H₄-R) {OC(=CH₂)Ar}

Full text of DOI:10.1021/om030275y

4124
Organometallics 2003, 22, 4124-4128
Rea ctivity of [MCl(η3-a llyl)(1,10-p h en a n th r olin e)(CO)2]
(M ) Mo, W) Com p lexes tow a r d En ola te An ion s
Dolores Morales, M. Elena Navarro Clemente,† J ulio Pe´rez,* Luc´ıa Riera, and
V´ıctor Riera
Departamento de Qu´ımica Orga´nica e Inorga´nica-IUQOEM, Universidad de Oviedo-CSIC,
33071 Oviedo, Spain
Daniel Miguel
Departamento de Qu´ımica Inorga´nica, Facultad de Ciencias, Universidad de Valladolid,
47071 Valladolid, Spain
Received April 15, 2003
The reactions of the complexes [MCl(η3-C3H4-R)(CO)2(phen)] (1a -c; M ) Mo, W) with
KCH2C(O)Ar afford the O-bound enolato complexes [M(η3-C3H4-R){OC(dCH2)Ar}(CO)2(phen)]
(2a -d ). On the other hand, the reactions of molybdenum chloro complexes with KCH2CN
yield the complexes [Mo(η3-C3H4-R)(CH2CN)(CO)2(phen)] (3a ,b), in which the nitrile enolate
ligand is C-bound. In addition to the spectroscopic characterization by means of IR and NMR,
the structures of [Mo(η3-C3H5){OC(dCH2)(naphthyl}(CO)2(phen)] (2c) and [Mo(η3-C3H4-Me-
2)(CH2CN)(CO)2(phen)] (3a ) were determined by X-ray diffraction.
In tr od u ction
(CO)3} fragment and carried out an extensive study of
their reactivity.5 Gibson reported the structural char-
acterization of the unexpected coordination modes
adopted by enolate groups in high-oxidation-state mo-
lybdenum complexes.6 We have recently found that
[MoCl(η3-allyl)(CO)2(N-N)] (N-N ) 2,2′-bipyridine
(bipy), 1,10-phenanthroline (phen)) complexes react with
dialkylmagnesium reagents or with sodium alkoxides
to afford the alkyl and alkoxo complexes [Mo(R)(η3-
allyl)(CO)2(N-N)]7 and [Mo(OR)(η3-allyl)(CO)2(N-N)],8
respectively; these complexes display interesting reac-
tivity.8,9 As an extension of this work, we set out to
explore the reactivity of enolate anions with [MoCl-
(η3-allyl)(CO)2(N-N)] complexes, and we report our
findings here.
Transition-metal enolates are intermediates in sev-
eral catalytic reactions;1 hence, the synthesis of well-
defined examples of this class of complexes and the
study of their reactivity has attracted much interest. A
growing number of such complexes have been charac-
terized, some of them by X-ray crystallography, and
different coordination modes of the enolato ligand have
been established, the most common of these being η1-C
or η1-O.2-4 With regard to molybdenum(II) and tung-
sten(II) complexes, which are the ones pertinent to the
work described here, Bergman and Heathcock reported
the synthesis of enolato complexes containing the {CpM-
* To whom correspondence should be addressed. E-mail: japm@
sauron.quimica.uniovi.es.
† Permanent address: ESIQIE-IPN, Edificio 6, 6217 UPALM,
Mexico D.F., Mexico.
Resu lts a n d Discu ssion
(1) (a) Trost, B. M.; Verhoeven, T. R. In Comprehensive Organome-
tallic Chemistry; Wilkinson, G., Stone, F. G. A., Abel, E. W., Eds.;
Pergamon Press: Oxford, U.K., 1982; Vol. 8, p 838. (b) Tsuji, J . J . Org.
Chem. 1987, 52, 2988. (c) Seebach, D. Angew. Chem., Int. Ed. Engl.
1988, 27, 1624. (d) Hamann, B. C.; Hartwig, J . F. J . Am. Chem. Soc.
1997, 119, 12382. (e) Kru¨ger, J .; Carreira, E. M. J . Am. Chem. Soc.
1998, 120, 837. (f) Sim, W.-S.; Li, T.-C.; Yang, P.-X.; Yeo, B.-S. J . Am.
Chem. Soc. 2002, 124, 4970.
(2) For leading examples of a O-bound enolates see the following.
Ru: (a) Hartwig, J . F.; Bergman, R. G.; Andersen, R. A. Organome-
tallics 1991, 10, 3326. (b) Hartwig, J . F.; Bergman, R. G.; Andersen,
R. A. Organometallics 1991, 10, 3344. (c) Pd: Andrieu, J .; Braunstein,
P.; Naud, F.; Adams, R. D. J . Organomet. Chem. 2000, 601, 43. (d)
Ti(IV): Agapie, T.; Diaconescu, P. L.; Mindiola, D. J .; Cummins, C. C.
Organometallics 2002, 21, 1329. (e) Ni: Ca´mpora, J .; Maya, C. M.;
Palma, P.; Carmona, E.; Gutie´rrez-Puebla, E.; Ruiz, C. J . Am. Chem.
Soc. 2003, 125, 1482. (f) Ca´mpora, J .; Maya, C. M.; Palma, P.; Carmona,
E.; Graiff, C.; Tiripicchio, A. Chem. Commun. 2003, 1742.
(3) For examples of C-bound enolates see ref 2a,b,e and the following.
(a) Ni compounds: Burkhardt, E. R.; Bergman, R. G.; Heathcock, C.
H. Organometallics 1990, 9, 30. Pd compounds: ref 3a and (b) Veya,
P.; Floriani, C.; Chiesi-Villa, A.; Rizzoli, C. Organometallics 1993, 12,
4899. (c) Vicente, J .; Abad, J . A.; Chicote, M.-T.; Abrisqueta, M.-D.;
Lorca, J .-A.; Ram´ırez de Arellano, M. C. Organometallics 1998, 17,
1564. (d) Bouchra, E. M.; Hani, E.; Vaissermann, J .; J aouen, G.
Organometallics 1995, 14, 3296. Pt compounds: (e) Matsumoto, K.;
Ochiai, M. Coord. Chem. Rev. 2002, 231, 229.
The complex [MoCl(η3-C3H4-Me-2)(CO)2(phen)]10 (1a )
reacted with a stoichiometric amount of a freshly
(4) For transition-metal complexes with enolato ligands in other
coordination modes see: (a) Murahashi, T.; Kurosawa, H. J . Orga-
nomet. Chem. 1999, 574, 142. (b) Ruiz, J .; Rodr´ıguez, V.; Cutillas, N.;
Pardo, M.; Pe´rez, J .; Lo´pez, G.; Chaloner, P.; Hitchcock, P. B.
Organometallics 2001, 20, 1973. (c) Vicente, J .; Arcas, A.; Ferna´ndez-
Herna´ndez, J . M.; Bautista, D. Organometallics 2001, 20, 2767.
(5) (a) Doney, J . J .; Bergman, R. G.; Heathcok, C. H. J . Am. Chem.
Soc. 1985, 107, 3724. (b) Burkhardt, E. R.; Doney, J . J .; Bergman, R.
G.; Heathcok, C. H. J . Am. Chem. Soc. 1987, 109, 2022.
(6) Cameron, P. A.; Britovsek, G. J . P.; Gibson, V. C.; Williams, D.
J .; White, A. J . P. Chem. Commun. 1998, 737.
(7) (a) Pe´rez, J .; Riera, L.; Riera, V.; Garc´ıa-Granda, S.; Garc´ıa-
Rodr´ıguez, E. J . Am. Chem. Soc. 2001, 123, 7469. (b) Pe´rez, J .; Riera,
L.; Riera, V.; Garc´ıa-Granda, S.; Garc´ıa-Rodr´ıguez, E.; Miguel, D.
Organometallics 2002, 21, 1622.
(8) Hevia, E.; Pe´rez, J .; Riera, L.; Riera, V.; Miguel, D. Organome-
tallics 2002, 21, 1750.
(9) (a) Reactivity of alkyl complexes: Pe´rez, J .; Riera, L.; Riera, V.;
Garc´ıa-Granda, S.; Garc´ıa-Rodr´ıguez, E.; Miguel, D. Chem. Commun.
2002, 384. (b) Reactivity of alkoxo complexes: Hevia, E.; Pe´rez, J .;
Riera, L.; Riera, V.; del R´ıo, I.; Garc´ıa-Granda, S.; Miguel, D. Chem.
Eur. J . 2002, 8, 4510.
(10) Powell, P. J . J . Organomet. Chem. 1977, 129, 175.
10.1021/om030275y CCC: $25.00 © 2003 American Chemical Society
Publication on Web 08/27/2003

Reactivity of Mo and W Complexes toward Enolate Anions
Organometallics, Vol. 22, No. 20, 2003 4125
precluded the acquisition of a significant 13C NMR
spectrum. However, H-C coupling constants of 151 and
166 Hz could be measured from the 13C satellites in the
1H NMR spectrum. These values are indicative of sp2
hybridization for the involved carbon, further confirming
the O-bound coordination mode of the enolato ligand.15
The naphthyl derivative [Mo(η3-C3H4-Me-2){OC(dCH2)-
(naphthyl)}(CO)2(phen)] (2b; its preparation and char-
acterization were similar to those of 2a ) showed an
enhanced solubility, and its 13C NMR, which confirms
the presence of a molecular mirror plane (a single
Mo-CO signal and symmetric phen and methallyl sets
of signals), featured singlets at 83.0 and 170.2 ppm,
attributed to the H2CdC and C-O-Mo groups, respec-
tively.
Sch em e 1
To investigate whether the enolate nucleophile did not
attack the allyl group because of the presence of the
methyl substituent on the allyl central carbon,16 the
reaction of [MoCl(η3-C3H5)(CO)2(phen)]17 (1b ) with
KCH2C(O)(naphthyl) was studied. The product was the
complex [Mo(η3-C3H5){OC(dCH2)(naphthyl)}(CO)2(phen)]
(2c), found to be isostructural with 2a ,b. The structure
of 2c in the solid state was determined by single-crystal
X-ray diffraction, and the result (Figure 1a and Tables
1 and 3) agrees with the solution spectroscopic data and,
in particular, confirms the presence of the O-bound
enolate. Thus, the distances O(3)-C(6) (1.314(10) Å) and
C(6)-C(7) (1.346(12) Å) are consistent with single and
double bonds, respectively.18 The Mo-O distance in
2c (2.079(6) Å) is slightly longer than in the hy-
droxo complex [Mo(OH)(η3-C3H4-Me-2)(CO)2(phen)]19
(2.055(5) Å); the difference can be attributed to the
better donor properties of the OH ligand (evidenced by
the lower ν(CO) wavenumber values, 1929 and 1843
cm-1 in THF, of the hydroxo complex) and its smaller
size. For both the η3-C3H5 and η3-C3H4-Me-2 ligands,
we have failed to detect by 1H NMR the olefins resulting
from enolate attack to the allyl group. We have recently
observed such products from the coupling between
η3-allyl and alkyl, alkynyl, or enolato (R) ligands in the
reaction of [MoCl(η3-allyl)(CO)2(dmpm)] (dmpm ) bis-
(dimethylphosphino)methane).20 The difference in re-
activity can be attributed to the relative positions of the
allyl and R groups: cis in the dmpm complexes and
trans, precluding the possibility of coupling, in the phen
complexes.
prepared solution of the enolate KCH2C(O)Ph in tet-
rahydrofuran (THF) to afford the new compound 2a (see
Scheme 1). The reaction was instantaneous, as shown
by a change in color (from red to red-brown) and in the
IR spectrum, the two similarly intense bands of 1a at
1950 and 1872 cm-1 being replaced by new ones at 1940
and 1857 cm-1, indicating the persistence of a cis-Mo-
(CO)2 unit. The spectroscopic and analytical data of 2a
(which was isolated in good yield as a brick red micro-
crystalline solid by means of a simple workup procedure,
as detailed in the Experimental Section) were consistent
with a composition of [Mo(η3-C3H4-Me-2){OC(dCH2)-
Ph}(CO)2(phen)]. The phen and methallyl 1H NMR
patterns indicated the presence of a molecular mirror
plane and, therefore, the geometry shown in Scheme 1.
The fact that 2a features an intact η3-methallyl group,
in line with our previous findings in the reactions of
[MoCl(η3-allyl)(CO)2(phen)] compounds with MgR2,7
NaOR,8 KN(H)Ar,11 and NaCN12 reagents, was not
anticipated, since resonance-stabilized carbanions, in-
cluding enolates, are known to attack the allyl ligand
of related pseudooctahedral molybdenum complexes.13
The coordination of the enolato ligand through its
oxygen atom was deduced by the occurrence of two
singlets at 4.40 and 4.30 ppm, characteristic of the
uncoordinated H2CdC moiety. Coordination of the
carbon atoms of the enolato ligand in addition to the
oxygen atom, found in several molybdenum com-
plexes,6,14 is precluded here by the saturated (18 elec-
trons) character of the metal atoms in the products
displayed in Scheme 1. The limited solubility of 2a
The tungsten complex [W(η3-C3H5){OC(dCH2)Ph}-
(CO)2(phen)] (2d ) was synthesized as described above
for the molybdenum counterparts by starting from the
known precursor [WCl(η3-C3H5)(CO)2(phen)],21 and its
characterization (see Experimental Section) indicated
a similar structure.
(14) η2(C,O)-enolate molybdenum complexes have been obtained by
Templeton by deprotonation of η2-acyls: Rusik, C. A.; Collins, M. A.;
Gamble, A. S.; Tonker, T. L.; Templeton, J . L. J . Am. Chem. Soc. 1989,
111, 2550.
(15) An anonymous reviewer is thanked for this suggestion.
(16) Borgmann, C.; Limberg, C.; Kaifer, E.; Pritzkow, H.; Zsolnai,
L. J . Organomet. Chem. 1999, 580, 214.
(11) Morales, D.; Pe´rez, J .; Riera, L.; Riera, V.; Miguel, D. Inorg.
Chem. 2002, 41, 4111.
(17) tom Dieck, H.; Friedel, H. J . Organomet. Chem. 1968, 14, 375.
(18) Allen, F. H.; Kennard, O.; Watson, D. G.; Brammer, L.; Orpen,
A. G.; Robin, R. J . Chem. Soc., Perkin Trans. 2 1987, S1-S19.
(19) Morales, D.; Navarro Clemente, M. E.; Pe´rez, J .; Riera, L.;
Riera, V.; Miguel, D. Organometallics 2002, 21, 4934.
(20) Pe´rez, J .; Riera, V.; Rodr´ıguez, A.; Garc´ıa-Granda, A. Angew.
Chem., Int. Ed. 2002, 41, 1427.
(12) Hevia, E.; Pe´rez, J .; Riera, L.; Riera, V.; Garc´ıa-Granda, S.;
Garc´ıa-Rodr´ıguez, E.; Miguel, D. Eur. J . Inorg. Chem. 2003, 1113.
(13) (a) Trost, B. M.; Lautens, M. J . Am. Chem. Soc. 1982, 104, 5543.
(b) Trost, B. M.; Merlic, C. A. J . Am. Chem. Soc. 1990, 112, 9590. (c)
For enolate attack at the η3-allyl ligand of other Mo(II) compounds
see: VanArsdale, W. E.; Winter, R. E. K.; Kochi, J . K. Organometallics
1986, 5, 645.
(21) Brisdon, B. J .; Griffin, G. F. J . Chem. Soc., Dalton Trans. 1975,
1999.

4126 Organometallics, Vol. 22, No. 20, 2003
Morales et al.
F igu r e 1. (a) Thermal ellipsoid (30% probability) plots of (a) 2c and (b) 3a .
Ta ble 1. Selected Bon d Dista n ces a n d An gles for
Com p lex 2c
Ta ble 2. Selected Bon d Dista n ces a n d An gles for
Com p lex 3a
Bond Distances (Å)
Bond Distances (Å)
Mo(1)-O(3)
O(3)-C(6)
Mo(1)-C(1)
Mo(1)-C(4)
Mo(1)-N(1)
Mo(1)-C(3)
2.079(6)
1.314(10)
1.924(11)
2.227(9)
2.234(7)
2.326(10)
C(6)-C(7)
1.346(12)
1.498(12)
1.937(13)
2.333(9)
2.260(8)
Mo(1)-C(7)
C(7)-C(8)
Mo(1)-C(2)
Mo(1)-N(2)
Mo(1)-C(3)
2.310(3)
1.394(4)
1.949(3)
2.231(2)
2.308(3)
N(8)-C(8)
1.135(4)
1.953(3)
2.225(2)
2.259(3)
2.320(3)
C(6)-C(31)
Mo(1)-C(2)
Mo(1)-C(5)
Mo(1)-N(2)
Mo(1)-C(1)
Mo(1)-N(1)
Mo(1)-C(4)
Mo(1)-C(5)
Bond Angles (deg)
Bond Angles (deg)
C(8)-C(7)-Mo(1) 114.7(2)
N(8)-C(8)-C(7)
177.2(4)
84.71(12)
C(6)-O(3)-Mo(1)
O(3)-C(6)-C(7)
C(1)-Mo(1)-O(3)
137.9(6)
123.9(9)
91.4(3)
C(7)-C(6)-C(31)
O(3)-C(6)-C(31)
C(2)-Mo(1)-O(3)
124.4(8)
111.8(7)
95.2(4)
C(1)-Mo(1)-C(7)
86.49(12) C(2)-Mo(1)-C(7)
of two strong bands at 1938 and 1857 cm-1, attributed
to a new cis-dicarbonyl species, and a weak band at 2187
cm-1, due to the presence of a CN group. Unlike the
reactions with ketone enolates described above, it was
now possible to observe during the IR monitoring of the
reaction the presence of an intermediate displaying two
strong νCO bands at 1912 and 1825 cm-1 and a weak
band at 2178 cm-1 assigned to the keteniminate ligand.
The reaction of the allyl complex 1b with KCH2CN
followed an identical course. The final products of these
reactions, 3a ,b, were isolated as crystalline purple solids
and characterized by IR and NMR (1H and 13C) and, in
the case of 3a , also by single-crystal X-ray diffraction
(Figure 1b and Tables 2 and 3). The presence of the Mo-
There are two important differences between the
enolates 2a -d and the previously isolated molybdenum-
(II) and tungsten(II) enolato complexes: 2a -d can be
easily obtained by the reaction of the potassium enolates
and the appropriate chloro precursors; in contrast,
alkaline enolates were found to be unreactive toward
[CpMCl(CO)3] (M ) Mo, W) complexes, and enolates of
the {CpM(CO)3} fragments were prepared by reaction
of 2-chloro ketones with Na[CpM(CO)3] reagents.5 On
the other hand, the enolato ligands in the complexes of
the aforementioned cyclopentadienylmetal fragments
are C-bound, whereas 2a -d are the only molybdenum-
(II) and tungsten(II) O-bound enolates.22 Heating THF
solutions of 2a -d at 50 °C for 7 h periods did not cause
any changes in the IR spectra, and higher temperatures
(65 °C) in THF led only to decomposition. Therefore, the
observed O-bound products seem to be the thermody-
namically preferred isomers. The preference for the
O-bound coordination mode suggests a somewhat hard
character of the {Mo(η3-allyl)(CO)2(phen)} fragment.
Indeed, the NCS ligand (a textbook example of an
ambident ligand that binds soft metal centers through
S and hard metal centers through N) is N-bound in the
crystallographically characterized [Mo(η3-C3H4-Me-2)-
(NCS)(CO)2(phen)] complexes.23
1
CH2CN grouping was indicated by H (singlets at 0.62
(3a ) and 0.71 (3b) ppm) and 13C NMR (CH2 and CN
carbons at 0.41 and 150.5 ppm, respectively, for 3b). The
X-ray structure confirmed the [Mo(η3-C3H4-Me-2)-
(CH2CN)(CO)2(phen)] (3a ) composition and, in particu-
lar, the C-bound coordination of the enolato ligand. The
structure of 3a was found to be similar to that of the
(22) See ref 14 and the following. (a) An O-bound enolate has been
recently found as part of a chelate ligand in a molybdenum complex:
Andrews, C. D.; Burrows, A. D.; J effery, J . C.; Lynam, J . M.; Mahon,
M. F. J . Organomet. Chem. 2003, 665, 15. (b) A nondetected molyb-
denum(II) O-bound enolato complex has been proposed to occur as an
intermediate: Hirao, T.; Fujihara, Y.; Tsuno, S.; Ohshiro, Y.; Agawa,
T. Chem. Lett. 1984, 367.
(23) Graham, A. J .; Fenn, R. H. J . Organomet. Chem. 1970, 25, 173.
The bipy analogue is isostructural: Graham, A. J .; Fenn, R. H. J .
Organomet. Chem. 1969, 17, 405.
Complex 1a reacted with a stoichiometric amount of
KCH2CN in THF. Within 1 h at room temperature, the
IR spectrum of the reaction mixture was found to consist

Reactivity of Mo and W Complexes toward Enolate Anions
Organometallics, Vol. 22, No. 20, 2003 4127
Ta ble 3. Cr ysta l Da ta a n d Refin em en t Deta ils for
Com p lexes 2c a n d 3a
under vacuum, the residue was extracted with CH2Cl2 (20 mL),
and the solution was filtered through a short column of
diatomaceous earth. In vacuo concentration and addition of
hexanes (20 mL) caused the precipitation of a brick red
microcrystalline solid, which was washed with hexane and
2c
3a
formula
fw
C
30H23Cl3MoN2O3
C20H17MoN3O2
427.31
661.79
dried under vacuum. Yield: 0.180, 75%. Anal. Calcd for C26H22
-
cryst syst
space group
a, Å
orthorhombic
P212121
19.693(4)
10.350(2)
13.524(3)
2756(9)
4
tetragonal
I41/2
MoN2O3: C, 61.66; H, 3.37; N, 5.53. Found: C, 61.40; H, 3.54;
1
N, 5.62. IR (THF; cm-1): 1940, 1857 (νCO). H NMR (CD2Cl2):
21.663(2)
21.663(2)
15.609(2)
7325.1(15)
16
δ 9.19 (dd (J H2,3 ) 3.5 Hz, J H2,4 ) 1.6 Hz), 2H, H2,9), 8.51 (dd
(J H4,3 ) 6.7 Hz, J H4,5 ) 1.3 Hz), 2H, H4,7), 7.99 [s, 2H, H5,6),
7.81 (dd, 2H, H3,8), 6.71 (m, 5H, Ph), 4.40 (s (1J CH ) 151 Hz),
1H, dCH2), 4.30 (s (1J CH ) 166 Hz), 1H, dCH2), 3.13 (s, 2H,
Hs), 1.33 (s, 2H, Ha), 0.95 (s, 3H, η3-C3H4(CH3)-2).
b, Å
c, Å
V, Å3
Z
T, K
299(2)
1.595
1330
299(2)
1.550
3456
Dc, g cm-3
F(000)
Syn th esis of [Mo(η3-C3H4-Me-2){OC(dCH2)(n a p h th yl)}-
(CO)2(p h en )] (2b). This compound was prepared as described
for 2a , from 1a (0.200 g, 0.47 mmol), 2′-acetonaphthone (0.083
g, 0.49 mmol), and KN(SiMe3)2 (1 mL of a 0.5 M solution in
toluene, 0.50 mmol). Yield: 0.170 g, 65%. Anal. Calcd for
λ(Mo KR), Å
cryst size, mm
µ, mm-1
scan range, deg
no. of rflns measd
no. of indep rflns
0.710 73
0.710 73
0.10 × 0.13 × 0.21 0.14 × 0.21 × 0.3
0.802
0.735
1.61 e θ e 23.30
16 193
1.83 e θ e 23.28
12 541
3957
C
30H24MoN2O3: C, 64.75; H, 4.35; N, 5.03. Found: C, 64.54;
H, 4.52; N, 4.92. IR (CH2Cl2; cm-1): 1936, 1847 (νCO). 1H NMR
(CD2Cl2): δ 9.13 (dd (J H2,3 ) 3.5 Hz, J H2,4 ) 1.6 Hz), 2H, H2,9),
8.43 (dd (J H4,3 ) 6.7 Hz, J H4,5 ) 1.3 Hz), 2H, H4,7), 7.93 (s, 2H,
2642
no. of data/restraints/ 3957/0/346
params
2642/0/236
goodness of fit on F2
R1/wR2 (I > 2σ(I))
R1/wR2 (all data)
1.049
0.0557/0.1541
0.0777/0.1667
1.022
0.0252/0.0633
0.0337/0.0673
H
5,6), 7.71 (dd, 2H, H3,8), 7.39 (m, 6H, naphthyl), 6.55 (s, 1H,
naphthyl), 4.63 (s (1J CH ) 160 Hz), 1H, dCH2), 4.49 (s (1J CH
)
154 Hz), 1H, dCH2), 3.08 (s, 2H, Hs), 1.29 (s, 2H, Ha), 0.91 (s,
3H, η3-C3H4(CH3)-2). 13C NMR (CD2Cl2): δ 228.75 (s, CO),
170.2 (Mo-OC(CH2)R), 151.5, 145.7, 138.0, 133.4, 130.5, 130.0,
128.8, 128.7, 128.1, 127.63, 126.9, 126.5, 125.2, 124.9, 124.2,
123.2 (s, phen and naphthyl), 83.2 (s, C2 of η3-C3H4-CH3-2),
83.0 (s, dCH2), 54.7 (s, C1 and C3 of η3-C3H4-CH3-2), 20.0 (s,
η3-C3H4-CH3-2).
Sch em e 2
Syn th esis of [Mo(η3-C3H5){OC(dCH2)(n a p h th yl)}(CO)2-
(p h en )] (2c). This compound was prepared as described for
2a , from 1b (0.100 g, 0.24 mmol), acetonaphthone (0.043 g,
0.25 mmol), and KN(SiMe3)2 (0.25 mmol). By slow diffusion of
hexane into a concentrated solution of 2c in CH2Cl2 at -20
°C red crystals were obtained, one of which was used for an
X-ray analysis. Yield: 0.09 g, 70%. Anal. Calcd for C29H22
-
MoN2O3: C, 64.21; H, 4.08; N, 5.16. Found: C, 64.32; H, 4.21;
N, 5.31. IR (CH2Cl2; cm-1): 1935, 1848 (νCO). 1H NMR
(CD2Cl2): δ 9.20 (dd (J H2,3 ) 3.5 Hz, J H2,4 ) 1.6 Hz), 2H, H2,9),
8.53 (dd (J H4,3 ) 6.7 Hz, J H4,5 ) 1.3 Hz), 2H, H4,7), 8.02 (s, 2H,
H
5,6), 7.96-7.30 (m, 8H, H3,8 of phen and naphthyl), 6.69 (s,
1H, naphthyl), 4.73 (s (1J CH ) 153 Hz), 1H, dCH2), 4.56 (s (1J CH
) 142 Hz), 1H, dCH2), 3.34 (d (J HH ) 6.3 Hz), 2H, Hs), 3.20
(m, 1H, Hc), 1.33 (d (J HH ) 9.1 Hz), 2H, Ha).
complex [Mo(η3-C3H4-Me-2)(CH3)(CO)2(phen)],7b includ-
ing very similar Mo-C(alkyl) distances (2.310(3) Å (3a )
and 2.339(3) Å). Given the structures of 3a ,b, we
propose that the intermediates observed in the reactions
leading to their preparation are the N-bound tautomers
depicted in Scheme 2.24 The N-bound coordination mode
would account for the relatively low IR νCO values; thus,
the amido complex [Mo(η3-C3H4-Me-2){N(H)(p-tol)}-
Syn th esis of [W(η3-C3H5){OC(dCH2)P h }(CO)2(p h en )]
(2d ). This compound was prepared as described for 2a , from
1c (0.075 g, 0.15 mmol), acetophenone (17 µL, 0.15 mmol), and
KN(SiMe3)2 (0.3 mL of a 0.5 M solution in toluene, 0.15
mmol). Yield: 0.075 mg, 86%. Anal. Calcd for C25H20N2O3W:
C, 51.74; H, 3.47; N, 4.82. Found: C, 51.47; H, 3.21; N, 5.01.
IR (CH2Cl2; cm-1): 1925, 1831 (νCO). 1H NMR (CD2Cl2):
δ
9.22 (m, 2H, H2,9), 8.54 (m, 2H, H4,7), 7.99 (s, 2H, H5,6), 7.95
(m, 2H, H3,8), 6.79 (m, 5H, Ph), 4.47 (s (1J CH ) 155 Hz), 1H,
(CO)2(phen)]11 features IR bands at 1926 and 1839 cm-1
.
dCH2), 4.32 (s (1J CH ) 157 Hz), 1H, dCH2), 3.09 (d (J HH
)
6.2 Hz), 2H, Hs), 2.28 (m, 1H, Hc), 1.50 (d (J HH ) 9.1 Hz),
2H, Ha).
Exp er im en ta l Section
Syn th esis of [Mo(η3-C3H4-Me-2)(CH 2CN)(CO)2(p h en )]
(3a ). KN(SiMe3)2 (0.98 mL of a 0.5 M solution in toluene, 0.49
mmol) was added to a cooled (-78 °C) solution of MeCN (26
µL, 0.49 mmol) in THF (10 mL); the mixture was stirred for
15 min and then added via cannula onto a solution of 1a (0.200
g, 0.46 mmol) in THF (10 mL). After 1 h of stirring, the purple
solution was evaporated to dryness, the residue was extracted
with CH2Cl2 (15 mL), and the extract was filtered through
diatomaceous earth and evaporated. By slow diffusion of
hexane into a concentrated solution of 3a in THF purple
crystals were obtained, one of which was used for X-ray
General conditions were reported elsewhere.19
Syn th esis of [Mo(η3-C3H4-Me-2){OC(dCH2)P h }(CO)2-
(p h en )] (2a ). KN(SiMe3)2 (1 mL of a 0.5 M solution in toluene,
0.50 mmol) was added to a cooled (-78 °C) solution of
acetophenone (58 µL, 0.5 mmol) in THF (10 mL). The mixture
was stirred for 15 min and then added via cannula onto a
solution of 1a (0.200 g, 0.46 mmol) in THF (10 mL). The
mixture was stirred for 30 min. The solvent was evaporated
(24) For recent leading references on C- or N-bound nitrile enolates,
see: (a) Naota, T.; Tannna, A.; Kamuro, S.; Murahashi, S.-I. J . Am.
Chem. Soc. 2002, 124, 6842. (b) Culkin, D. A.; Hartwig, J . F. J . Am.
Chem. Soc. 2002, 124, 9330.
diffraction. Yield: 0.145 g, 70%. Anal. Calcd for C20H17
-
MoN3O2: C, 56.21; H, 4.01; N, 9.83. Found: C, 56.02; H, 4.31;

4128 Organometallics, Vol. 22, No. 20, 2003
Morales et al.
N, 9.64. IR (THF; cm-1): 1938, 1857 (νCO), 2187 (νCN). 1H NMR
(CD2Cl2): δ 8.96 (dd (J H2,3 ) 3.5 Hz, J H2,4 ) 1.6 Hz), 2H, H2,9),
8.46 (dd (J H4,3 ) 6.7 Hz, J H4,5 ) 1.3 Hz), 2H, H4,7), 8.00 (s, 2H,
125.1 (s, phen), 150.5 (s, CN), 73.1 (s, C2 of η3-C3H4-CH3-2),
54.8 (s, C1 and C3 of η3-C3H4-CH3-2), 0.41 (s, CH2CN).
H
5,6), 7.83 (m, 8H, H3,8), 2.76 (s, 2H, Hs), 1.58 (s, 2H, Ha), 0.62
Ack n ow led gm en t. We thank the Ministerio de
Ciencia y Tecnolog´ıa (Grants MCT-00-BQU2000-0220
and BQU2002-03414) and the Principado de Asturias
(PR-01-GE-7) for support and predoctoral (L.R.) and
postdoctoral (D.M.) scholarships. M.E.N.C. thanks the
PCI-AL.E-2002, AECI (Spain) and IPN (Mexico) for a
visiting professorship. Dr. A. D. Hopkins (University of
Cambridge) is thanked for proofreading the final version
of the paper.
(s, 2H, CH2CN), 0.57 (s, 3H, η3-C3H4(CH3)-2). 13C NMR
(C6D6): δ 230.2 (s, CO), 151.4, 144.8, 135.6, 129.8, 124.2 (s,
phen), 81.2 (s, C2 of η3-C3H4-CH3-2), 52.4 (s, C1 and C3 of η3-
C3H4-CH3-2), 18.49 (s, η3-C3H4-CH3-2), 0.01 (s, CH2CN).
Syn t h esis of [Mo(η3-C3H 5)(CH2CN)(CO)2(p h en )] (3b ).
This compound was prepared as described for 3a , from 1b (0.05
g, 0.12 mmol), MeCN (10 µL, 0.17 mmol), and KN(SiMe3)2 (0.35
mL, 0.17 mmol). By diffusion of hexane into a concentrated
solution of 3b in THF at -20 °C a purple microcrystalline solid
was obtained. Yield: 0.040 g, 80%. Anal. Calcd for C19H15
-
Su p p or tin g In for m a tion Ava ila ble: Text giving a gen-
eral description of crystal structure determination for com-
pounds 2c and 3a and tables giving positional and thermal
parameters, bond distances, and bond angles for 2c and 3a .
This material is available free of charge via the Internet at
http://pubs.acs.org.
MoN3O2: C, 55.22; H, 3.66; N, 10.16. Found: C, 55.45; H, 3.51;
N, 9.92. IR (THF; cm-1): 1936, 1849 (νCO), 2183 (νCN). 1H NMR
(CD2Cl2): δ 9.02 (dd (J H2,3 ) 3.5 Hz, J H2,4 ) 1.6 Hz), 2H, H2,9),
8.50 (dd (J H4,3 ) 6.7 Hz, J H4,5 ) 1.3 Hz), 2H, H4,7), 8.01 (s, 2H,
H
5,6), 7.61 (m, 2H, H3,8), 3.34 (s br, 2H, Hs), 2.94 (m, 1H, Hc),
1.57 (d (J HH ) 8.4 Hz), 2H, Ha), 0.71 (s, 2H, CH2CN). 13C NMR
(CD2Cl2): δ 230.2 (s, CO), 152.4, 144.7, 137.33, 130.5, 127.6,
OM030275Y