Acid-catalyzed carbonylation of lactone to cyclic anhydride on tungsten metal

Article abstract of DOI:10.1021/om970431z

Facile carbonylation of the cis-vinyl complex Cp(CO)₃W[CH=CH(COMe)] (2, Cp=η⁵-C₅H₅) followed by cyclization affords the γ-lactone complex Cp(CO)₂W[η³-CHCHC(Me)OC(O)] (4). Further carbonylat

Full text of DOI:10.1021/om970431z

4636
Organometallics 1997, 16, 4636-4644
Acid -Ca ta lyzed Ca r bon yla tion of La cton e to Cyclic
An h yd r id e on Tu n gsten Meta l
Lien Lee, Ding-J en Chen, Ying-Chih Lin,* Yih-Hsing Lo, Chien Hsing Lin,
Gene-Hsiang Lee, and Yu Wang
Department of Chemistry, National Taiwan University,
Taipei, Taiwan 10764, Republic of China
Received May 27, 1997X
Facile carbonylation of the cis-vinyl complex Cp(CO)3W[CHdCH(COMe)] (2, Cp ) η5-C5H5)
followed by cyclization affords the γ-lactone complex Cp(CO)2W[η3-CHCHC(Me)OC(O)] (4).
Further carbonylation of 4 induced by the presence of acid in CH3CN gives the cyclic
anhydride complex Cp(CO)(CH3CN)W[η3-CHCHC(Me)C(O)OC(O)] (9). The reaction of 4 with
Me2NH causes ring opening to yield the zwitterionic complex Cp(CO)2W[η2-Me2NdC(Me)-
CHdCHCOOH] (6). The cyclic anhydride ligand of 9 remains unchanged when 9 is treated
with nucleophiles. For example, the reaction of Me2NH with 9 affords the imine-coordinated
complex Cp(CO)(Me2NC(Me)dNH)W[η3-CHCHC(Me)C(O)OC(O)] (14), and the reaction of
NaBH4 with 9 generates the amine-coordinated complex Cp(CO)(MeCH2NH2)W[η3-CHCHC-
(Me)C(O)OC(O)] (15). The structures of 4, 6, 9, and 14 have also been determined by X-ray
diffraction analysis. The allylic ligand in 9 is in an endo conformation.
In tr od u ction
Co2(CO)8 under a nitrogen atmosphere to yield the
azetidine-2,4-dione.5 The carbonylation of lactone to
anhydride has recently been reported in a molybdenum
system.6 We have been interested in carbonylation
reactions of unsaturated organic molecules assisted by
transition-metal complexes and their regioselectivity.7
In this paper, we report carbonylation reactions of metal
vinyl complexes with a ketone group at Câ, followed by
cyclization leading to lactones and further carbonylation
of the lactone unit on the metal affording a cyclic
anhydride.
Metal-assisted cyclocarbonylation has attracted con-
siderable attention;1 particularly, dicarbonylation of
terminal and/or internal alkynes catalyzed by various
transition-metal complexes yielding lactone and other
products has been the focus of many reports.2 Transi-
tion-metal-mediated carbonylative ring expansion of
various heterocyclic compounds leading to lactones,
lactams, and thiolactones has also been reviewed re-
cently.3 Further carbonylation, however, has received
much less attention: indazolone was reacted with CO
in the presence of Co catalyst, affording 2,4-dioxo-
1,2,3,4-tetrahydroquinazoline,4 and R-lactams were re-
acted with CO in the presence of Rh catalyst or with
Resu lts a n d Discu ssion
Syn t h esis of La ct on e Com p lexes. A mixture of
cis- and trans-vinyl complexes Cp(CO)3W(η1-
CHdCHCOMe) (2) in a 5:1 ratio was isolated by rapid
workup in 84% total yield if the reaction of 3-butyn-2-
one with Cp(CO)3WNa (1), at 0 °C was quenched with
cold hexane as soon as the starting material was
depleted, as shown by the IR spectra (about 15 min).
However, if carried out at 0 °C for 80 min, the same
reaction afforded the allylic γ-lactone complex Cp-
X Abstract published in Advance ACS Abstracts, September 15, 1997.
(1) (a) Hegedus, L. S. Transition Metals in the Synthesis of Complex
Organic Molecules; University Science Books: Mill Valley, CA, 1994;
Chapter 4, p 103. (b) Heck, R. F.; Wu, G.; Tao, W.; Rheingold, A. L. In
Catalysis of Organic Reactions; Blackburn, D. W., Ed.; Marcel Dek-
ker: New York, 1990; p 169. For representative examples of cyclocar-
bonylation, see: (c) Faller, J . W.; Chen, C. C.; Mattina, M. J .;
J akubowski, A. J . Organomet. Chem. 1973, 52, 361. (d) Murray, T. F.;
Norton, J . R. J . Am. Chem. Soc. 1979, 101, 4107. (e) Benaim, J .;
Giulieri, F. J . Organomet. Chem. 1979, 165, C28. (f) Semmelhack, M.
F.; Brickner, S. J . J . Am. Chem. Soc. 1981, 103, 3945. (g) Billington,
D. C.; Pauson, P. L. Organometallics 1982, 1, 1560. (h) Schrieber, S.
L.; Semmekia, T.; Crowe, W. E. J . Am. Chem. Soc. 1986, 108, 3128. (i)
Tsuji, Y.; Kondo, T.; Watanabe, Y. J . Mol. Catal. 1987, 40, 295. (j)
Magnus, P.; Principe, M. J .; Slater, J . J . Org. Chem. 1987, 52, 1483.
(k) Negishi, E. I.; Sawada, H.; Tour, J . M.; Wei, Y. J . Org. Chem. 1988,
53, 913. (l) Matsuda, I.; Ogiso, A.; Sato, S. J . Am. Chem. Soc. 1990,
112, 6120. (m) Frank-Neuman, M.; Michelotti, E. L.; Simler, R.;
Vernier, J . M. Tetrahedron Lett. 1992, 33, 7361. (n) Berk, S. C.;
Grossman, S. L.; Buchwald, S. L. J . Am. Chem. Soc. 1993, 115, 4912.
(2) (a) Tsuji, J .; Nogi, T. J . Am. Chem. Soc. 1966, 88, 1289. (b) Heck,
R. F. J . Am. Chem. Soc. 1972, 94, 2712. (c) Hong, P.; Mise, T.;
Yamazaki, H. Chem. Lett. 1981, 989. (d) Chiusoli, G. P.; Costa, M.;
Pergreffi, P.; Reverberi, S.; Salerno, G. Gazz. Chim. Ital. 1986, 691.
(e) Kiji, J . Konishi, H.; Okano, T.; Kometani, S.; Iwasa, A. Chem. Lett.
1987, 313. (f) Doyama, K.; J oh, T.; Onitsuka, K.; Shiomara, T.;
Takahashi, S. J . Chem. Soc., Chem. Commun. 1987, 649. (g) Zargarian,
D.; Alper, H. Organometallics 1991, 10, 2914.
(CO)2W[η3-CHCHC(Me)OC(O)] (4) as the only isolable
product in 64% yield (see Scheme 1). The molybdenum
analogue of the allylic γ-lactone complex Cp(CO)2Mo-
[η3-CHCHC(Me)OC(O)] (5) was similarly prepared. How-
ever, no vinyl complex could be observed for Mo. All
the reactions that yielded 2-5 were carried out in the
presence of H2O and MeOH for rendering the proton
using THF as a solvent. Facile transformation of 2-cis
(5) Reberto, D.; Alper, H. Organometallics 1984, 3, 1767.
(6) Butters, C.; Carr, N.; Deeth, R. J .; Green, M.; Green, S. M.;
Mahon, M. F. J . Chem. Soc., Dalton Trans. 1996, 2299.
(3) Khumtaveeporn, K.; Alper, H. Acc. Chem. Res. 1995, 28, 414.
(4) Murahashi, S.; Horiie, S. J . Am. Chem. Soc. 1956, 78, 4816.
(7) Tseng, T. W.; Wu, I. Y.; Tsai, J . H.; Lin, Y. C.; Chen, D. J .; Lee,
G. H.; Cheng, M. C.; Wang, Y. Organometallics 1994, 13, 3963.
S0276-7333(97)00431-7 CCC: $14.00 © 1997 American Chemical Society

Carbonylation of Lactone to Anhydride on W
Organometallics, Vol. 16, No. 21, 1997 4637
Sch em e 1
to 4 was completed within 1 h at room temperature.
This transformation in CDCl3 was monitored by NMR
spectroscopy. The resonances attributed to 2-cis gradu-
ally decreased in intensity, while the resonances at-
tributed to 4 appeared. The 2-trans isomer at the initial
stage remained unchanged and finally after 45 min
decomposed to give some unidentifiable products.
1
In the H NMR spectrum of the isomeric mixture of
2, the resonances at δ 8.75, 7.41 and at δ 9.22, 6.79 with
the characteristic coupling constants of 11.7 and 17.0
Hz are assigned to the vinyl protons for the cis and trans
isomers, respectively. In CDCl3, 4 displays only one
form with the resonances at δ 5.70, 3.36 assignable to
the lactone-ring protons, and in CD3CN at -15 °C, both
1
the endo and exo isomers are observed in the H NMR
spectrum. Likewise, the 13C NMR spectrum of 4 in CD3-
CN at -15 °C shows resonances at δ 21.7 and 18.7
assignable to the methyl groups of the endo and exo
isomers, respectively. The chemical shifts of the 13C
resonances of the three allylic carbon atoms at δ 95.1,
75.8, 29.1 (endo) and δ 100.2, 60.1, 26.4 (exo) are
unusual.8 The structure of 4 has been firmly estab-
lished by a single-crystal X-ray diffraction study. An
ORTEP drawing is shown in Figure 1. Disorder is found
for the lactone ligand; i.e., C(7) and O(2) atoms lie in a
symmetry plane. The allylic ligand is in an exo confor-
mation with the C(6)-C(7) bond distance (1.33(4) Å)
much shorter than the C(7)-C(8) distance (1.53(4) Å),
which implies some degree of π conjugation between the
η3-allyl and the lactone carbonyl group.9 This is com-
patible with the unusual chemical shift of the 13C
F igu r e 1. An ORTEP drawing of 4 showing the atom
numbering scheme and with 50% probability of the el-
lipsoid.
resonances described previously. Probably, in addition
to the η3-bonding mode, the η1:η2-bonding mode is
another form of the allylic ligand, probably through the
effect of the neighboring lactone group; however, with
the disorder in the crystal, this viewpoint requires
further study. The C(6)-O(2) bond length of 1.45(4) Å
is longer than that of a regular C-O single bond,10
consistent with the facile cleavage described below. The
structure of 5 displays similar features: namely, a
disordered lactone ring and significantly unequal C-C
bond lengths in the allylic ligand are observed also in
5. The distance from the metal to the central carbon of
an allylic ligand is typically 0.05-0.19 Å shorter than
the distance from the metal to the terminal carbon. This
has been attributed to overlap between a filled d orbital
(8) A metal-coordinated η3-allyl group usually gives 13C resonances
at δ 80-90 for a terminal carbon and at δ 110-130 for a central
carbon: Collman, J . P.; Hegedus, L. S.; Norton, J . R.; Finke, R. G.
Principles and Application of Organotransition Metal Chemistry;
University Science Books: Mill Valley, CA, 1987; Chapter 2, pp 176-
177.
(9) The corresponding C-C distances of 1.390(7) and 1.415(7) Å in
(10) Allene, F. H.; Kennard, O.; Watson, D. G.; Brammer, L.; Orpen,
A. G.; Taylor, R. J . Chem. Soc., Perkin Trans. 2 1987, S1-S19.
an Mo-coordinated η3-allyl group are reported in ref 6.

4638 Organometallics, Vol. 16, No. 21, 1997
Lee et al.
on the metal and both of the unoccupied orthogonal π*
orbitals of the central carbon.11 In the allyl system of
4 and 5, even with the η1:η2-bonding anomaly, this same
feature is observed.
Formation of 4 could proceed via carbonylation of
2-cis, giving the η3-acryloyl complex 3 followed by
nucleophilic attack of the acetyl oxygen to the acryloyl
carbonyl carbon atom to form a five-membered lactone
ring with concomitant shift of the allylic coordination
onto the three non-carbonyl carbon atoms to give 4. Such
a transformation has been implicated in reactions
involving Pd,12 Rh,13 Co,14 and Ni,15 but no such complex
has been isolated by a carbonylation process. The
lactonyl complexes of Mo reported by Green and his co-
workers6 were prepared by direct complexation of 1-Me3-
SiO-substituted furan followed by a fluoride-anion-
induced desilylation. Several previous examples of
acryloyl complexes,16 mostly from carbonylation of vinyl
complexes, are known, but none of them form a lactone
complex. This mechanism is consistent with our obser-
vation that the 2-trans vinyl complex would not yield
the lactone product, since after carbonylation, with the
acetyl group in a syn configuration, formation of a cyclic
structure is infeasible.
Interestingly, the complex Cp(CO)(PPh3)Mo[η3-(O)-
CCHCHCOOMe] (3a ) is prepared directly from the
reaction of the stronger metal nucleophile Cp(CO)2-
(PPh3)Mo- with HCtCCO2Me; i.e., CO insertion takes
place but a better donor ligand, PPh3, in 3a hinders
further attack of the oxygen nucleophile. The similar
Mo complex Cp(CO)(PPh3)Mo[η3-(O)CCHCH2] has been
prepared17 via CO insertion of a vinyl precursor. In 3a ,
the characteristic 13C resonance at δ 258.1 is assigned
to the terminal allylic CO and one of the allylic protons
shows J H-P coupling with the PPh3 ligand. Therefore,
we believe that the electronic effect plays an important
role in carbonylation of vinyl complex. Facile carbony-
lation observed in the preparation of 3a is promoted by
the more electron rich metal center with the better
σ-donor PPh3. However, the same factor might hinder
cyclization to give the five-membered ring.
F igu r e 2. An ORTEP drawing of 6 showing the atom
numbering scheme and with 50% probability of the el-
lipsoid.
to the olefinic protons of 6-Z, indicates a Z configuration.
Complex 6-Z slowly transforms to the corresponding E
form in about 7 days at -10 °C in CH2Cl2 in our attempt
to grow single crystals. In the 1H NMR spectrum, a
J H-H value of 14.1 Hz for the resonances at δ 3.15 and
2.70 indicates an E configuration. The structure of 6-E,
as shown in Figure 2, has been determined by a single-
crystal X-ray diffraction study. There are two crystal-
lographically independent molecules in the unit cell of
6-E, and the two show no significant difference. The
olefinic ligand is in an E configuration. The C(4)-C(5)
bond distance of 1.46(1) Å is characteristic for a η2-
bonded olefin. The C(6)-N bond length of 1.315(9) Å
is shorter than that of a regular C-N single bond,5
consistent with the imine formulation. The following
steps rationalize the formation of 6. Amine attacks the
methyl-substituted terminal allylic carbon and causes
ring opening at the weaker lactone C-O bond. The
resultant allylic complex with a carboxylate group
undergoes an anti-syn transformation followed by a
lone pair donation from the amine group to yield 6. No
methylation is observed when 6 is treated with CH3I.
Treatment of 4 with MeONa follows a similar reaction
pathway to afford the yellow allylic product Cp(CO)2W-
[η3-Me(MeO)CCHCHCOONa] (7), which upon treatment
with MeI generates Cp(CO)2W[η3-Me(MeO)CCHCH-
COOMe] (8) in 91% overall yield (see Scheme 1). The
νCO stretchings at 1912 and 1826 cm-1 in the IR
spectrum of 7 indicate neutral character of the metal
center. In the initial stage of the reaction of 4 with
MeONa, an intermediate with νCO stretchings at 1859
and 1753 cm-1 in the IR spectrum is observed. The
much lower νCO stretchings could possibly be due to
some anionic species resulting from addition of MeO-
at the metal center. Subsequent migration of the
methoxy group to the lactone ligand causes opening of
the five-membered ring and generates the product. This
result is different from that observed in the reaction of
amine. This distinct reactivity may be attributed to the
reluctance of the oxygen atom to form an oxonium
cation.
Reaction of 4 with Me2NH first generates the rare
zwitterionic olefin-coordinated imine complex Cp(CO)2W-
[η2-(Z)-(Me2NdC(Me))CHdCHCOOH] (6-Z) in high yield
(see Scheme 1). The νCO stretching bands of 6-Z appear
at 1886 and 1790 cm-1 in the IR spectrum, indicating
localization of the anionic charge at the metal center.
1
In the H NMR spectrum the coupling constant J H-H of
8.0 Hz for the resonances at δ 3.40 and 2.46, attributed
(11) Bowden, F. L.; Giles, R. Coord. Chem. Rev. 1976, 20, 81.
(12) (a) Sugihara, T.; Cope´ret, C.; Owczarezyk, Z.; Harring, L. S.;
Negishi, E. J . Am. Chem. Soc. 1994, 116, 7923. (b) Cope´ret, C.;
Sugihara, T.; Wu, G.; Shimoyama, I.; Negishi, E. J . Am. Chem. Soc.
1995, 117, 3422.
(13) Doyama, K.; J oh, T.; Onitsuka, K.; Shiohara, T.; Takahashi, S.
J . Chem. Soc., Chem. Commun. 1987, 649.
(14) Krafft, M. E.; Pankowski, J . Tetrahedron Lett. 1990, 31, 5139.
(15) (a) Ryang, M.; Sawa, Y.; Somasundaram, S. N.; Murai, S.;
Tsutsumi, S. J . Organomet. Chem. 1972, 46, 375. (b) Carmona, E.;
Gutie´rrez-Puebla, E.; Monge, A.; Mar´ın, J . M.; Paneque, M.; Poveda,
M. L. Organometallics 1989, 8, 967.
(16) (a) Heck, R. F.; Breslow, D. S. J . Am. Chem. Soc. 1961, 83, 1097.
(b) Beck, W.; Brix, H. J . Organomet. Chem. 1976, 121, 211. (c) Mitsudo,
T.; Watanabe, H.; Watanebe, Y.; Nitani, N.; Takegami, Y. J . Chem.
Soc., Dalton Trans. 1979, 395. (d) Petillon, F. Y.; le Quere, J . L.; le
Floch-Perennou, F.; Guerchais, J . E.; Gomes le Lima, M. B. J .
Organomet. Chem. 1984, 255, 231.
Cyclic An h yd r id e Com p lex fr om Ca r bon yla tion
of th e La cton e Com p lex. In the presence of a
catalytic amount of CF3COOH, 4 in CH3CN undergoes
carbonylation to form another C-C bond, giving Cp-
(17) (a) Ridgway, C.; Winter, M. J .; Woodward, S. Polyhedron 1989,
8, 1859. (b) Adams, H.; Bailey, N. A.; Gauntlett, J . T.; Harkin, I. M.;
Winter, M. J .; Woodward, S. J . Chem. Soc., Dalton Trans. 1991, 1117.
(CO)(CH3CN)W[η3-CHCHC(Me)C(O)OC(O)] (9) in 87%

Carbonylation of Lactone to Anhydride on W
Organometallics, Vol. 16, No. 21, 1997 4639
pathway. In addition, the much weaker C-O bond of
4, as determined by the X-ray diffraction analysis, leads
to ready rupture of this bond. Nucleophilic attack of
the carboxylate onto the terminal CO leads to an
acylcarbene, which may undergo further coupling of the
carbene with the acylate to yield a η3 six-membered
cyclic anhydride. Carbon-carbon bond formation be-
tween the donor atoms of adjacent acyl and alkenyl
ligands has been reported.19 “Carbene migratory inser-
tion”,20 i.e. rearrangement of an alkyl or aryl group at
the carbene carbon, has been implicated in many
reactions. An alternative pathway would be carbony-
lation of carbene to yield vinylketene21 which is followed
by ring closure to give 9. A very similar mechanism
for the transformation of a lactonyl to an anhydride
ligand has been proposed.6 A stronger acid such as
HBF4 might protonate the carboxylate group, thus
deterring the step of nucleophilic attack or ring closure.
F igu r e 3. An ORTEP drawing of 9 showing the atom
numbering scheme and with 50% probability of the el-
lipsoid.
In the reaction of 9 with Me2NH, the allyl ligand with
the cyclic anhydride functionality remains unchanged,
but addition of the dimethylamine to the CtN bond of
the coordinated CH3CN yields Cp(CO)[Me2NC(Me)d
isolated yield. No D labeling is observed when a
stoichiometric amount of CF3COOD is used. The IR
spectrum of 9 shows only one νCO band in the terminal
carbonyl region. Spectroscopic data are not sufficient
to firmly establish the structure of 9; therefore, an X-ray
diffraction analysis was carried out. There are again
two crystallographically independent molecules in the
unit cell of 9 with no significant differences between
them. An ORTEP drawing of one molecule is shown in
Figure 3. It is clear that the allylic group embedded in
the cyclic anhydride is in an endo conformation with
the methyl substituent lying trans to the coordinated
CH3CN. Also, the two allylic C-C bond distances are
about equal (1.36(2) and 1.37(2) Å), indicating a normal
allylic ligand. The 1H (δ 5.20, 2.67) and 13C (δ 38.6, 36.1)
NMR data for the CH groups of the allylic ligand are
also consistent with this observation. The solvent plays
an important role in this reaction; i.e., in THF or in
chloroform, no reaction is observed. However, if HBF4
in ether is used, an air-sensitive protonation intermedi-
ate is readily formed as a precipitate. The IR spectrum
of this intermediate in the terminal carbonyl region
gives two sets of absorption bands at 1987, 1915 cm-1
and 1963, 1880 cm-1, indicating the presence of two
isomers, each possibly with two terminal CO ligands.
Thus, protonation presumably occurs at one of the
oxygen atoms of the lactone ring with no C-C bond
NH]W[η3-CHCHC(Me)C(O)OC(O)] (14).22 Complex 14
1
has been characterized by a two-dimensional H-13C
HMBC NMR experiment as well as by a single-crystal
1
X-ray diffraction analysis. In the H NMR spectrum of
14, the broad resonance at δ 5.53 is assigned to the
imine NH, and the two doublet resonances at δ 5.15 and
1.99 are assigned to the ring protons of the cyclic
anhydride. In the 13C NMR spectrum, the resonance
at δ 171.0 is assigned to the imine CdNH carbon atom.
An ORTEP drawing of 14 is shown in Figure 4. The
bond distance C(8)-N(1) of 1.296(8) Å, as compared to
the C(8)-N(2) distance of 1.345(9) Å, clearly indicates
1
coordination of the imine group. The H NMR signal
for the imine proton (at δ 5.53) is consistent with this
structure.
In the presence of NaBH4, the coordinated CH3CN
ligand of 9 is further reduced to afford the coordinated
amine ligand, again while the cyclic anhydride ligand
in 9 remains unaltered (see Scheme 1). Specifically, the
(19) (a) Lukehart, C. M.; Srinivasan, K. Organometallics 1982, 1,
1247. (b) Lukehart, C. M.; Myers, J . B., J r.,; Sweetman, B. J . J .
Organomet. Chem. 1986, 316, 319.
1
formation in the first step. The H NMR data for the
(20) (a) Threlkel, R. S.; Bercaw, J . W. J . Am. Chem. Soc. 1981, 103,
2650. (b) Thorn, D. L.; Tulip, T. H. J . Am. Chem. Soc. 1981, 103, 5984.
(c) Barger, P. T.; Bercaw, J . E. Organometallics 1984, 3, 278. (d) Thorn,
D. L. Organometallics 1985, 4, 192. (e) Fryzuk, M. D.; MacNeil, P. A.;
Rettig, S. J . J . Am. Chem. Soc. 1985, 107, 6708. (f) Stenstrom, Y.; J ones,
W. M. Organometallics 1986, 5, 178. (g) J erknakoff, P.; Cooper, N. N.
Organometallics 1986, 5, 747. (h) J ones, W. D.; Kosar, W. P. J . Am.
Chem. Soc. 1986, 108, 5640. (i) Stenstrom, Y.; Koziol, P.; Palenik, G.
J .; J ones, W. M. Organometallics 1987, 6, 2079. (j) Carter, E. A.;
Goddard, W. A., III. Organometallics 1988, 7, 675. (k) Conti, N. J .;
J ones, W. M. Organometallics 1988, 7, 1666. (l) Cantrell, R. D.; Shevlin,
P. B. J . Am. Chem. Soc. 1989, 111, 2349. (m) O’Connor, J . M.; Pu, L.;
Rheingold, A. L. J . Am. Chem. Soc. 1989, 111, 4129. (n) Trace, R. L.;
Sanchez, J .; Yang, J .; Yin, J .; J ones, W. M. Organometallics 1992, 11,
1440. (o) Hughes, R. P.; Trujillo, H. A.; Rheingold, A. L. J . Am. Chem.
Soc. 1993, 115, 1583. (p) Yang, J .; Ying, J .; Abboud, K. A.; J ones, W.
M. Organometallics 1994, 103, 971. (q) Braun, T.; Gevert, O.; Werner,
H. J . Am. Chem. Soc. 1995, 117, 7291.
(21) (a) Do¨tz, K. H.; Muhlemeier, J . Angew. Chem., Int. Ed. Engl.
1982, 21, 929. (b) Semmelhack, M. F.; Tamura, R.; Schnatter, W.;
Springer, J . J . Am. Chem. Soc. 1984, 106, 5363. (c) Hegedus, L. S.;
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1994, 13, 1214. (c) Michelin, R. A.; Mozzon, M.; Bertani, R. Coord.
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Y. Y. J . Am. Chem. Soc. 1996, 118, 777.
allylic group are very similar to those for 4. In the
presence of CH3CN, this intermediate readily converts
to 9 and in CH3CH2CN it converts to Cp(CO)(CH3CH2-
CN)W[η3-CHCHC(Me)C(O)OC(O)] (9′).
A proposed pathway for the formation of 9 is depicted
in Scheme 1: protonation at one of the lactone oxygen
atoms induced opening of the five-membered ring. This
is followed by the shift from a η3 to η1 coordination mode
of the allylic ligand assisted by the coordination of CH3-
CN a solvent molecule, leading to a vinylcarbene
intermediate18 with a pendant carboxylate anion. Our
observation that interconversion of the endo and exo
isomers occurs possibly via a η1-allylic group in CD3CN
but not in CDCl3 is consistent with this proposed
(18) (a) Esteruelas, M. A.; Lahoz, F. J .; Onate, E.; Oro, L. A.; Zeier,
B. Organometallics 1994, 13, 4258. (b) Wu, Z.; Nguyen, S. T.; Grubbs,
R. H.; Ziller, J . W. J . Am. Chem. Soc. 1995, 117, 5503. (c) Miller, S. J .;
Grubbs, R. H. J . Am. Chem. Soc. 1995, 117, 5855. (c) Kirmse, W.;
Strehlke, I. K.; Steenken, S. J . Am. Chem. Soc. 1995, 117, 7007.

4640 Organometallics, Vol. 16, No. 21, 1997
Lee et al.
ligands. Photolytic decarbonylation of 11 resulted in
chelation of one of the ester carbonyl oxygens and
cleanly gave Cp(CO)2W[C(CO2Me)dCH(C(O)OMe)] (12)
in 84% yield. The IR spectrum of 12 shows two strong
νCO stretching bands at 1948 and 1873 cm-1, charac-
teristic of a neutral CpW(CO)2 moiety, and a medium-
intensity absorption at 1701 cm-1 assignable to the νCO
1
band of the acetate group. In the H NMR spectrum of
12 at room temperature, the characteristic Cp resonance
appears at δ 5.51 and the vinyl and acetate protons
appear at δ 6.35, 3.89 and 3.82, respectively; all display
singlet patterns. On the basis of these spectroscopic
data, the structure of 12 most likely contains a five-
membered oxametallacycle, even though a four-mem-
bered oxametallacycle is an alternative.25 Various
methods are known for preparation of the five-mem-
bered oxametallacycles.26
F igu r e 4. An ORTEP drawing of 14 showing the atom
numbering scheme and with 50% probability of the el-
lipsoid.
reaction gives Cp(CO)(MeCH2NH2)W[η3-CHCHC(Me)C-
In conclusion, a conversion of a lactone complex to a
cyclic anhydride via proton-catalyzed carbonylation has
been achieved. The acetyl group at the â-carbon of the
vinyl ligand on tungsten promotes carbonylation, lead-
ing to formation of the γ-lactone complex. Conversion
of the lactone complex via carbonylation to cyclic
anhydride takes place in the presence of a catalytic
amount of CF3COOH. The cyclic anhydride ligand is
inert relative to the coordinated CH3CN ligand. Thus,
nucleophilic attack of amine at the CH3CN ligand or
reduction of CH3CN to ethylamine by NaBH4 is easily
achieved, leaving the cyclic anhydride ligand unaltered.
1
(O)OC(O)] (15) in high yield. In the H NMR spectrum
of 15, all the characteristic resonances (δ 5.14 and 2.19)
of the cyclic anhydride remain and additional reso-
nances at δ 3.17, 2.76, and 1.02 attributed to the
coordinated ethylamine are observed. Unlike the lacto-
nyl ligand in 4, the cyclic anhydride ligand in 9 is
somewhat inert.
Oth er Vin yl Com p lexes. To explore the chemical
reactivity of other vinyl complexes, we carried out the
reaction of 1 with 1.5 equiv of HCtCCO2Me in THF at
0 °C for 1 day, giving a mixture of the cis and trans
isomers (4:1) of Cp(CO)3W[CHdCH(CO2Me)] (10) in
about 40% total yield. Interestingly, a similar reaction
of 1 with MeO2CCtCCO2Me in THF at 0 °C for 1 h gives
only the trans-vinyl complex Cp(CO)3W[C(CO2Me)dCH-
(CO2Me)] (11) in 65% yield. The presence of the two
-CO2Me substituents may exert steric hindrance; thus,
the reaction gave only the trans product and its electron-
withdrawing ability expedites nucleophilic addition of
the metal anion and the rate of the reaction is the
fastest among the three alkyne molecules. The prepa-
ration of metal vinyl complexes deserves some comment
here. A general route to metal vinyl complexes is the
insertion of activated acetylenes into metal-hydride
bonds.23 However, the number and variety of factors,
such as temperature, solvent, stoichiometry, and poly-
functional nature of both the alkyne and the metal-
hydrogen bond, that may affect the process has made
the reaction unpredictable. In our study, we found that
the reaction of alkynes bearing moderately electron-
withdrawing substituents with metal carbonylate an-
ions is actually a better method, giving a relatively
higher yield for the preparation of metal vinyl com-
plexes. For comparison, in CDCl3 the reactions of
Cp(CO)3WH with HCtCCO2Me and with HCtCCOMe
required 4 days and 1 day to afford 10 and directly 4 in
only <10% and <40% yields, respectively. The reaction
of Cp(CO)3WH with MeO2CCtCCO2Me also required
4 days, yielding [Cp(CO)2W]2[MeO2CCtCCO2Me]24 as
the major product and less than 30% of 11 as a minor
product.
Exp er im en ta l Section
Gen er a l P r oced u r es. All manipulations were performed
under nitrogen using vacuum-line, drybox, and standard
Schlenk techniques. CH3CN and CH2Cl2 were distilled from
CaH2 and diethyl ether and THF from Na/ketyl. All other
solvents and reagents were of reagent grade and were used
without further purification. NMR spectra were recorded on
Bruker AC-200 and AM-300WB FT-NMR spectrometers at
room temperature (unless stated otherwise) and are reported
in units of δ with residual protons in the solvent as an internal
standard (CDCl3, δ 7.24; CD3CN, δ 1.93; C2D6CO, δ 2.04). FAB
mass spectra were recorded on a J EOL SX-102A spectrometer.
Cp(CO)3WNa,27 Cp(CO)3MoNa,28 and Cp(CO)2(PPh3)MoNa29
were prepared by following the methods reported in the
literature. Elemental analyses and X-ray diffraction studies
were carried out at the Regional Center of Analytical Instru-
mentation at National Taiwan University.
P r ep a r a tion of Cp W(CO)3[CHdCHC(O)CH3] (2).
A
solution of Cp(CO)3WNa (0.55 g, 1.54 mmol) in 20 mL of THF
at -78 °C was transferred to a solution of 3-butyn-2-one (0.16
mL, 2.0 mmol) in 40 mL of MeOH (containing 1 mL of H2O)
at 0 °C, and the reaction mixture was stirred for 15 min. The
solvent was rapidly removed under vacuum, and the residue
(25) (a) Alt, H. G.; Herrmann, G. S.; Engelhardt, H. E.; Rogers, R.
D. J . Organomet. Chem. 1987, 331, 329. (b) van der Zeijden, A. A. H.;
Bosch, H. W.; Berke, H. Organometallics 1992, 11, 563.
(26) (a) Alt, H. G. J . Organomet. Chem. 1990, 383, 125. (b) Adams,
R. D.; Chen, L. F.; Wu, W. G. Organometallics 1992, 11, 3505. (c)
Etienne, M.; White, P. S.; Templeton, J . L. Organometallics 1993, 12,
4010. (d) J ohnson, J . K.; Grubbs, R. H.; Ziller, J . W. J . Am. Chem.
Soc. 1993, 115, 8130. (e) Shih, K. Y.; Fanwick, P. E.; Walton, R. A. J .
Am. Chem. Soc. 1993, 115, 9319.
No carbonylation was observed for 10 and 11 under
1 atm of CO pressure or in the presence of phosphine
(27) Lee, L.; Wu, I. Y.; Lin, Y. C.; Lee, G. H.; Wang, Y. Organome-
tallics 1994, 13, 2521.
(28) Huang, B. C.; Wu, I. Y.; Lin, Y. C.; Peng, S. M.; Lee, G. H. J .
Chem. Soc., Dalton Trans. 1995, 2351.
(29) Kegley, S. E.; Brookhart, M.; Husk, G. R. Organometallics 1982,
1, 760.
(23) (a) Otsuka, S.; Nakamura, A. Adv. Organomet. Chem. 1976,
14, 245. (b) Bianchini, C.; Meli, A.; Perruzini, M.; Vizza, F.; Frediani,
P. Organometallics 1990, 9, 1146. (c) van der Zeijden, A. A. H.; Bosch,
H. W.; Berke, H. Organometallics 1992, 11, 563.
(24) Laine, R. M.; Ford, P. C. J . Organomet. Chem. 1977, 124, 29.

Carbonylation of Lactone to Anhydride on W
Organometallics, Vol. 16, No. 21, 1997 4641
was extracted with 30 mL of ca. 5:1 hexane/THF a t 0 °C. The
extract was filtered and evaporated to dryness to give ca. 5:1
cis/trans isomeric yellow solids 2 (0.51 g, 84%). Spectroscopic
data for 2 are as follows. IR (cm-1, KBr): 2021 (s), 1920 (vs),
1738 (m), 1512 (s) ν(CdO). 1H NMR (20 °C, ppm; cis and trans
forms were observed in CDCl3): cis form, 8.75 (d, J H-H ) 11.7
Hz, 1H, dCH), 7.41 (d, J H-H ) 11.7 Hz, 1H, dCH), 5.59 (s,
5H, Cp), 2.17 (s, 3H, CH3); trans form, 9.22 (d, J H-H ) 17.0
Hz, 1H, dCH), 6.79 (d, J H-H ) 17.0 Hz, 1H, dCH), 5.61 (s,
5H, Cp), 2.17 (s, 3H, CH3). MS (FAB, m/z): 404 (M+, W )
186), 376 (M+ - CO), 348 (M+ - 2CO), 334 (M+ - vinyl), 320
(M+ - 3CO). Anal. Calcd for C12H10O4W: C, 35.85; H, 2.51.
Found: C, 35.74; H, 2.32.
P r epar ation of CpW(CO)2[η2-Me2NdCMeCHdCHCOOH]
(6). To a yellow solution of 4 (0.10 g, 0.25 mmol) in 30 mL of
CH3CN was added 0.08 mL (0.71 mmol, 40% in H2O) of Me2-
NH by a syringe, resulting in a color change to orange-red.
The mixture was stirred for 15 min, and then the solvent was
removed in vacuo. The residue was washed with hexane and
recrystallized from CH2Cl2/hexane to give the orange-red solid
6-Z (0.10 g, 88%). The Z configuration is determined by the
J H-H value (8.0 Hz) between the two olefinic protons. Spec-
troscopic data for 6-Z are as follows. IR (cm-1, CH3CN): 1886
(vs), 1790 (s), 1683 (m), 1623 (m) ν(CdO). 1H NMR (CDCl3,
ppm): 5.28 (s, 5H, Cp), 3.40 (d, J H-H ) 8.0 Hz, 1H, dCH),
2.94 (s, 6H, 2 NCH3), 2.46 (d, J H-H ) 8.0 Hz, 1H, dCH), 1.80
(s, 3H, CH3). 13C NMR (CDCl3, ppm): 242.9, 234.3 (M-CO),
183.1 (CdN), 161.6 (CO2H), 90.7 (Cp), 35.5 (NCH3), 37.6, 27.4
(2 dCH), 17.6 (CH3). MS (FAB, m/z): 449 (M+, W ) 186), 421
(M+ - CO), 393 (M+ - 2CO). Anal. Calcd for C14H17NO4W:
C, 37.60; H, 3.83. Found: C, 36.95; H, 3.64. Upon recrystal-
lization between the interface of the ether/CH2Cl2 solution at
-10 °C for 7 days, complex 6-Z converted to 6-E. 1H NMR
Syn t h esis
of
Com p lex
Cp (P P h 3)(CO)Mo(η3-
OdCCHCHCOOMe) (3a ). To a solution of Cp(PPh3)(CO)2-
MoI (0.25 g, 0.41 mmol) in 20 mL of THF was added BuLi
(0.7 mL, 1.6M, 1.12 mmol) at 0 °C. The solution was stirred
for 10 min; then HCtCCOOMe (0.20 mL, 2.24 mmol) and 0.3
mL of MeOH were added. After 40 min, the reaction was
quenched with 4 mL of water and the solvent was removed
under vacuum. The residue was extracted with ether and the
ether solution dried over MgSO4. Removal of ether followed
by silica gel packed column chromatography (eluted with 1:1
hexane/ether) yielded the yellow oily product 3a (0.19 g, 82%).
Spectroscopic data for 3a are as follows. IR (cm-1, CHCl3):
1925 (vs), 1709 (m), 1671 (m) ν(CdO). 1H NMR (CDCl3,
ppm): 7.50-7.20 (m, 15H, Ph), 4.81 (s, 5H, Cp), 3.62 (s, 3H,
CH3), 2.91 (dd, J P-H ) 11.4 Hz, J H-H ) 5.5 Hz, 1H, CH), 1.77
(d, J H-H ) 5.5 Hz, 1H, CH). 13C NMR, (CDCl3, ppm): 258.1
(CdO), 238.1 (d, J P-C ) 15.8 Hz, M-CO). 177.7 (COOMe),
133.2, 130.4, 128.5 (Ph), 92.7 (Cp), 50.7 (OCH3), 44.5 (d, J P-C
) 3.1 Hz, allylic C), 23.5 (allylic carbon). 31P NMR (CDCl3,
data for 6-Z (CDCl3, ppm): 5.42 (s, 5H, Cp), 3.15 (d, J H-H
)
14.1 Hz, 1H, dCH), 2.70 (d, J H-H ) 14.1 Hz, 1H, dCH), 2.17
(s, 6H, 2 NCH3), 2.12 (s, 3H, CH3). The structure of complex
6-E was confirmed by single-crystal X-ray diffraction analysis.
The reaction of 4 (0.10 g, 0.25 mmol) with EtNH2 (0.05 mL,
70% in H2O, 0.77 mmol) gave the product CpW(CO)2[η2-EtN-
(H)dCMeCHdCHCOOH] (6a ) (0.10 g, 0.021 mmol) in 84%
yield. Spectroscopic data for 6a -Z are as follow. IR (cm-1
,
CH3CN): 1882 (vs), 1790 (s), 1681 (m), 1620 (m) ν(CdO). 1H
NMR (CDCl3, ppm): 11.4 (br, 1H, dNH), 5.31 (s, 5H, Cp), 3.32
(d, J H-H ) 7.2 Hz, 1H, dCH), 3.17 (m, 2H, CH2N), 2.96 (q,
J H-H ) 7.2 Hz, 2H, 2 NCH2), 2.46 (d, J H-H ) 7.2 Hz, 1H, dCH),
2.20 (s, 3H, CH3), 1.26 (t, J H-H ) 7.2 Hz, 3H, CH3), 1.09 (t,
J H-H ) 7.2 Hz, 3H, CH3). MS (FAB, m/z): 446 (M+, W ) 186),
418 (M+ - CO), 391 (M+ - 2CO).
ppm): 56.6 (PPh3). MS (FAB, m/z): 567 (M+ + 1), 508 (M+
+
1 - CO2Me). Anal. Calcd for C29H25O4MoP: C, 61.71; H, 4.46.
Found: C, 61.82; H, 4.74.
Rea ction of 4 w ith MeONa . To a solution of 4 (0.10 g,
0.25 mmol) in CH3CN was added a MeOH solution containing
MeONa (0.02 g, 0.37 mmol), and the solution was stirred at
room temperature for 2.5 h. (If monitored by the IR spectra,
the reaction first gave an intermediate with the IR absorption
bands at 1859 and 1753 cm-1 in about 10 min. This interme-
diate disappeared in about 40 min.) The solvent was removed
from the resulting light yellow solution, and the product was
extracted with 2 × 10 mL of CH2Cl2. After filtration, the
volume of the filtrate was reduced to about 5 mL and 20 mL
of hexane was added to bring about a light yellow precipitate,
which was filtered and washed with 2 × 5 mL of hexane. The
product was dried under vacuum and was identified as Cp-
(CO)2W[η3-Me(MeO)CCHCHCOONa] (7) by spectroscopic tech-
niques. Spectroscopic data for 7 are as follows. IR (cm-1,v
CH3CN): 1912 (s), 1826 (s), 1704 (m) ν(CdO). 1H NMR (CD3-
CN, ppm): 5.47 (s, 5H, Cp), 4.48 (d, J H-H ) 8.7 Hz, 1H, CH),
3.29 (s, 3H, CH3), 1.77 (d, J H-H ) 8.7 Hz, 1H, CH), 1.53 (s,
3H, CH3). 13C NMR (CDCl3, ppm): 235.5, 229.5 (M-CO),
181.2 (CdO), 117.5 (allyl central C), 93.7 (Cp), 56.1 (OCH3),
54.0, 34.2 (2 CH), 20.6 (CH3). All isolated complex 7 was
further treated with MeI (0.05 mL, 0.80 mmol) in 20 mL of
CH3CN. The solution was heated to 55 °C for 1 h, and after
cooling the solvent was removed under vacuum. The product
was extracted with 2:1 hexane/CH2Cl2, and after removal of
the solvent, Cp(CO)2W[η3-Me(MeO)CCHCHCOOMe] (8; 0.10
g) was obtained in 91% yield. Spectroscopic data for 8 are as
follows. IR (cm-1, CH3CN): 1925 (s), 1837 (s), 1691 (w)
ν(CdO). 1H NMR (CDCl3, ppm): 5.39 (s, 5H, Cp), 4.52 (d, J H-H
P r ep a r a tion of Cp (CO)2W[η3-CHCHC(CH3)OC(O)] (4).
A solution of Cp(CO)3WNa (0.55 g, 1.54 mmol) in 20 mL of
THF at -78 °C was added to a solution of 3-butyn-2-one (0.16
mL, 2.0 mmol) in 40 mL of MeOH (containing 1 mL of H2O)
at 0 °C, and the reaction mixture was stirred for 80 min. The
solvent was then removed under vacuum, and the residue was
extracted with 30 mL of ca. 2:1 hexane/CH2Cl2. The extract
was filtered and evaporated to dryness to give yellow solids 4
(0.40 g, 64%). Spectroscopic data for 4 are as follows. IR
(cm-1, KBr): 1943 (vs), 1858 (s), 1739 (m), 1730 (m), 1455 (s)
ν(CdO). 1H NMR (-15 °C, ppm; endo and exo forms were
observed in CD3CN): exo form, 5.76 (br, J H-H ) 3.1 Hz, 1H,
CH), 5.64 (br, 5H, Cp), 3.33 (d, J H-H ) 3.1 Hz, 1H, CH), 2.01
(s, 3H, CH3); endo form, 5.88 (br, J H-H ) 3.0 Hz, 1H, dCH),
5.45 (s, 5H, Cp), 3.33 (d, J H-H ) 3.0 Hz, 1H, CH), 2.07 (s, 3H,
CH3). 13C NMR (-15 °C, CD3CN, ppm): exo form, 229.8, 223.6
(M-CO), 177.1 (CdO), 100.2, 60.1, 26.4 (allylic carbon), 93.3
(Cp), 18.7 (CH3); endo form, 229.8, 223.6 (M-CO), 177.1 (CdO),
95.1, 75.8, 29.1 (allylic carbon), 93.6 (Cp), 21.7 (CH3). MS
(FAB, m/z): 404 (M+, W ) 186), 376 (M+ - CO), 348 (M+
2CO), 334 (M+ - vinyl), 320 (M+ - 3CO). Anal. Calcd for
12H10O4W: C, 35.85; H, 2.51. Found: C, 35.82; H, 2.44. The
-
C
Mo analogue CpMo(CO)2[η3-CHCHC(CH3)OC(O)] (5; 0.08 g)
is similarly prepared from the reaction of [CpMo(CO)3]Na (0.10
g, 0.37 mmol) and 3-butyn-2-one (0.04 mL, 0.50 mmol) in 68%
yield. Spectroscopic data for 5 are as follows. IR (cm-1
,
KBr): 1940 (vs), 1845 (s), 1730 (m) ν(CdO). 1H NMR (CDCl3,
ppm): 5.56 (d, J H-H ) 2.6 Hz, 1H, CH), 5.33 (s, 5H, Cp), 3.54
(d, J H-H ) 2.6 Hz, 1H, CH), 2.19 (s, 3H, CH3). 1H NMR (CD3-
CN, ppm): 5.90 (br, J H-H ) 2.6 Hz, 1H, dCH), 5.46 (br, 5H,
Cp), 3.49 (d, J H-H ) 2.6 Hz, 1H, CH), 2.15 (s, 3H, CH3). 13C
NMR (25 °C, CDCl3, ppm): 221.4 (M-CO), 178.0 (CdO), 94.7,
77.2, 28.9 (allylic carbon), 92.5 (Cp), 21.7 (CH3). MS (FAB,
m/z): 316 (M+, Mo ) 98), 288 (M+ - CO), 260 (M+ - 2CO),
247 (M+ - vinyl), 232 (M+ - 3CO). Anal. Calcd for C12H10O4-
Mo: C, 45.88; H, 3.21. Found: C, 45.80; H, 3.18.
) 8.3 Hz, 1H, CH), 3.65, 3.34 (s, 6H, 2 OCH3), 1.77 (d, J H-H
)
8.3 Hz, 1H, CH), 1.67 (s, 3H, CH3). 13C NMR (CDCl3, ppm):
232.8, 224.9 (M-CO), 176.4 (CdO), 117.8 (allyl central C), 92.4
(Cp), 55.5, 51.6 (2 OCH3), 52.4, 25.9 (2 CH), 19.8 (CH3). MS
(FAB, m/z): 448 (M+), 420 (M+ - CO), 392 (M+ - 2CO).
P r ep a r a tion of Cp W(CO)(CH 3CN)[η3-CHCHC(CH 3)C-
(O)OC(O)] (9). A solution of 4 (0.50 g, 1.24 mmol) in 45 mL

4642 Organometallics, Vol. 16, No. 21, 1997
Ta ble 1. Cr ysta l a n d In ten sity Collection Da ta for Cp (CO)2W[η3-CHCHC(Me)OC(O)] (4),
Lee et al.
Cp (CO)2W[η2-Me2NdC(Me)CHCHCOOH] (6), Cp (CO)(CH3CN)W[η3-CHCHC(Me)C(O)OC(O)] (9), a n d
Cp (CO)(Me2NC(Me)dNH)W[η3-CHCHC(Me)C(O)OC(O)] (14)
mol formula
mol wt
C12H10O4W (4)
401.05
C15H20NO4WCl2 (6)
533.08
C14H13O4NW (9)
443.11
C16H20N2O4W (14)
488.19
space group
a, Å
b, Å
c, Å
Pnma
P1h
P21/c
C2/c
26.991(7)
8.387(3)
10.996(2)
12.564(4)
8.393(3)
8.042(2)
14.222(5)
13.894(4)
13.989(3)
10.449(3)
22.006(6)
82.32(3)
84.21(3)
84.83(2)
1815.1(8)
4
0.35 × 0.45 × 0.5
14.940(3)
R, deg
â, deg
102.62(2)
102.85(2)
γ, deg
V, Å3
1159.5(6)
4
0.10 × 0.20 × 0.45
2697.3(15)
8
0.20 × 0.30 × 0.40
3297.3(16)
8
0.30 × 0.30 × 0.30
Z
cryst dimens, mm3
Mo KR radiation: γ, Å
2θ range, deg
scan type
0.7093
2-50
2-45
2-50
2-50
θ/2θ
total no. of rflns
no. of unique rflns, I > 2σ(I)
abs cor, µ, cm-1
transmission factors
R
1061
716
101.59
0.507-1.000
0.028
4743
3914
65.16
0.659-1.000
0.026
4735
3265
87.47
0.591-1.000
0.046
2895
1725
71.76
0.826-1.000
0.021
Rw
0.029
0.025
0.047
0.021
GOF
2.51
-0.86, +0.99
2.34
-0.81, +0.99
2.64
-2.65, +2.29
1.82
-0.72, +0.67
∆F (in final map), e/Å3
Ta ble 2. Selected Bon d Dista n ces (Å) a n d An gles
Rea ction of 9 w ith Am in e. A solution of 9 (0.10 g, 0.23
mmol) in 15 mL of CH3CN was treated with Me2NH (0.05 mL,
40% in H2O), and the reaction mixture was stirred for 15 min.
Then the solvent was removed under vacuum, and the residue
was extracted with 30 mL of ca. 2:1 hexane/CH2Cl2. The
extract was filtered and evaporated to dryness to give the
(d eg) of Cp (CO)2W[η3-CHCHC(Me)OC(O)] (4)
W-C
1.940(12)
2.290(15)
2.359(10)
2.313(11)
2.206(13)
2.36(3)
2.40(3)
1.155(14)
1.429(20)
C(4)-C(4)a
C(4)-C(3)
C(7)-C(6)
C(7)-C(8)
O(3)-C(9)
C(6)-O(2)
C(6)-C(5)
C(9)-O(2)
C(9)-C(8)
1.35(3)
1.367(19)
1.33(4)
1.53(4)
1.19(4)
1.45(4)
1.47(4)
1.39(3)
1.41(4)
W-C(2)
W-C(4)
W-C(3)
W-C(7)
W-C(6)
W-C(8)
C(1)-O(1)
C(2)-C(3)
orange-yellow solid Cp(CO)[Me2NC(Me)dNH]W[η3-CHCHC-
(Me)C(O)OC(O)] (14; 0.10 g, 91%). Spectroscopic data for 14
are as follows. IR (cm-1, CH3CN): 1875 (s), 1709 (s), 1665 (s)
ν(CdO); 1570 (m) ν(CdN). 1H NMR (CDCl3, ppm): 5.53 (br
s, 1H, NH), 5.15 (d, J H-H ) 4.9 Hz, 1H, CH), 4.96 (s, 5H, Cp),
2.92 (br, 6H, NMe2), 2.04 (s, 3H, MeCd), 1.99 (d, J H-H ) 4.9
Hz, 1H, CH), 1.98 (s, 3H, Me). 13C NMR (CDCl3, ppm): 240.1
(CO), 175.8, 175.5 (CdO), 171.0 (CdN), 93.7 (Cp), 76.6 (CH),
42.1 (CH), 39.0 (NCH3), 38.3 (CCH3), 23.1 (CH3), 20.3
(CH3CdN). MS (FAB, m/z): 488 (M+), 460 (M+ - CO). Anal.
Calcd for C16H20O4N2W: C, 39.36; H, 4.13; N, 5.73. Found:
C, 38.95; H, 4.29; N, 5.96.
C(1)-W-C(1)a
W-C(1)-O(1)
C(3)-C(2)-C(3)a
C(4)a-C(4)-C(3)
C(2)-C(3)-C(4)
C(6)-C(7)-C(8)
C(7)-C(6)-O(2)
79.8(4)
178.1(9)
105.5(15)
109.4(12)
107.9(14)
102.1(22)
113.1(2)
C(7)-C(6)-C(5)
O(2)-C(6)-C(5)
O(3)-C(9)-O(2)
O(3)-C(9)-C(8)
O(2)-C(9)-C(8)
C(6)-O(2)-C(9)
C(7)-C(8)-C(9)
121(3)
117(3)
115.5(24)
134(3)
110(3)
103.9(20)
105(3)
of CH3CN at 0 °C was treated with CF3COOH (0.1 mL, 1.29
mmol), and the reaction mixture was stirred for 15 min. Then
the solvent was removed under vacuum, and the residue was
extracted with 30 mL of ca. 2:1 hexane/CH2Cl2. The extract
was filtered and evaporated to dryness to give the orange-
yellow solid 9 (0.48 g, 87%). Spectroscopic data for 9 are as
follows. IR (cm-1, CH2Cl2): 1917 (s), 1722 (s), 1682 (m)
ν(CdO). 1H NMR (CDCl3, ppm): 5.20 (d, J H-H ) 4.7 Hz, 1H,
CH), 5.05 (s, 5H, Cp), 2.67 (d, J H-H ) 4.7 Hz, 1H, CH), 2.51
(MeCN), 2.00 (s, 3H, CH3). 13C NMR (CDCl3, ppm): 231.6
(J W-C ) 179.5 Hz, W-CO), 176.0, 175.2 (CdO), 135.0 (CN),
93.0 (Cp), 75.3 (CH), 38.6 (J W-C ) 21.5 Hz, CMe), 36.1 (J W-C
) 19.7 Hz, CH), 23.6 (CH3), 4.6 (CH3CN). MS (FAB, m/z): 443
Rea ction of 9 w ith Na BH4. A solution of 9 (0.10 g, 0.23
mmol) in 20 mL of CH3OH was treated with NaBH4 (0.095 g,
2.51 mmol), and the reaction mixture was stirred for 10 min,
giving a red-brown solution. Then the solvent was removed
under vacuum, and the residue was extracted with 2 × 10 mL
of CH2Cl2. The extract was filtered and evaporated to about
3 mL; then 20 mL of hexane was added to cause precipitation
of the orange-yellow product, which was filtered and dried
under vacuum to give Cp(CO)(MeCH2NH2)W[η3-CHCHC-
(Me)C(O)OC(O)] (15; 0.087 g, 85%). Spectroscopic data for 15
are as follows. IR (cm-1, CH3CN): 1890 (s), 1709 (s), 1662
(m) ν(CdO). 1H NMR (CD3CN, ppm): 5.14 (d, J H-H ) 4.7 Hz,
1H, CH), 5.05 (s, 5H, Cp), 3.17, 2.76 (br, 2H, NCH2), 2.19 (d,
J H-H ) 4.7 Hz, 1H, CH), 1.94 (Me), 1.02 (t, J H-H ) 7.1 Hz, 3H,
CH3). 13C NMR (CD3CN, ppm): 241.7 (CO), 176.7, 176.0
(CdO), 94.1 (Cp), 75.9 (CH), 48.7 (NCH2), 37.9 (CMe), 38.0
(CH), 24.1 (CH3), 18.6 (CH3). MS (FAB, m/z): 447 (M+), 419
(M+ - CO), 402 (M+ - CH3CH2NH2), 374 (M+ - CH3CH2-
NH2,CO). Anal. Calcd for C14H17O4NW: C, 37.60; H, 3.83;
N, 3.13. Found: C, 37.95; H, 4.09; N, 3.36.
(M+), 402 (M+ - CH3CN), 374 (M+ - CH3CN,CO), 318 (M+
-
C6H5O3). Anal. Calcd for C14H13O4NW: C, 37.95; H, 2.96; N,
3.16. Found: C, 37.69; H, 2.75; N, 3.07. The reaction can also
be carried out in the presence of a catalytic amount of acid.
The reaction of 4 (0.50 g, 1.24 mmol) with HBF4 (2.00 mL) in
20 mL of ether at -78 °C for 30 min afforded a protonation
intermediate (0.41 g, 65%) as a red precipitate, which was
washed with 20 mL of hexane. Spectroscopic data for the
protonation intermediate are as follows. IR (cm-1, THF): 1987
(vs), 1963 (s), 1915 (m), 1880 (m) ν(CdO). 1H NMR (C2D6CO,
ppm): 5.93 (d, J H-H ) 2.5 Hz, 1H, CH), 5.70 (br, 5H, Cp), 3.35
(d, J H-H ) 3.1 Hz, 1H, CH), 2.08 (s, 3H, CH3). MS (FAB,
m/z): 403 (M+ - BF4), 375 (M+ - BF4, CO), 347 (M+ - BF4,
2CO).
P r ep a r a tion of Cp W(CO)3[CHdCHCO2CH3] (10).
A
solution of Cp(CO)3WNa prepared from Na/Hg reduction of
[CpW(CO)3]2 (0.14 g, 0.21 mmol) in 20 mL of THF was added
to a solution of methyl propynoate (0.05 mL, 0.71 mmol) in 20
mL of THF (containing 1.0 mL of H2O and 1.0 mL of MeOH)

Carbonylation of Lactone to Anhydride on W
Organometallics, Vol. 16, No. 21, 1997 4643
Ta ble 3. Selected Bon d Dista n ces (Å) a n d An gles
Ta ble 5. Selected Bon d Dista n ces (Å) a n d
An gles (d eg) of Cp (CO)(Me2NC(Me)dNH)-
(d eg) of Cp (CO)2W[η2-Me2NdC(Me)CHCHCOOH] (6)
W[η3-CHCHC(Me)C(O)OC(O)] (14)
W-C(1)
1.944(7)
1.920(8)
2.253(7)
2.285(7)
1.164(9)
1.179(9)
1.456(9)
1.241(8)
1.320(9)
1.455(10)
1.460(9)
1.500(10)
1.315(9)
1.458(9)
1.444(10)
W′-C(1′)
1.923(8)
1.923(8)
2.242(6)
2.255(7)
1.179(9)
1.173(9)
1.466(9)
1.219(8)
1.329(8)
1.423(9)
1.476(9)
1.473(11)
1.323(10)
1.441(11)
1.446(11)
W-C(2)
W′-C2′
W-N(1)
2.186(5)
1.954(7)
2.266(7)
2.164(7)
2.269(7)
1.296(8)
1.345(9)
1.468(9)
1.455(9)
1.144(8)
C(2)-C(3)
C(2)-C(6)
C(3)-C(4)
C(4)-C(5)
C(4)-C(7)
C(5)-O(3′)
C(5)-O(4)
C(6)-O(2)
C(6)-O(3′)
C(8)-C(9)
1.436(10)
1.440(10)
1.441(10)
1.424(10)
1.508(11)
1.391(9)
1.213(9)
1.193(9)
1.394(9)
1.503(10)
W-C(4)
W-C(5)
W′-C(4′)
W′-C(5′)
W-C(1)
W-C(2)
C(1)-O(1)
C(2)-O(2)
C(3)-C(4)
C(3)-O(3)
C(3)-O(4)
C(4)-C(5)
C(5)-C(6)
C(6)-C(7)
C(6)-N
C(1′)-O(1′)
C(2′)-O(2′)
C(3′)-C(4′)
C(3′)-O(3′)
C(3′)-O(4′)
C(4′)-C(5′)
C(5′)-C(6′)
C(6′)-C(7′)
C(6′)-N′
W-C(3)
W-C(4)
N(1)-C(8)
N(2)-C(8)
N(2)-C(10)
N(2)-C(11)
C(1)-O(1)
N(1)-W-C(1)
81.69(24)
C(4)-C(5)-O(3)
C(4)-C(5)-O(4)
O(3)-C(5)-O(4)
C(2)-C(6)-O(3)
C(2)-C(6)-O(3)
O(2)-C(6)-O(3)
N(1)-C(8)-N(2)
N(1)-C(8)-C(9)
N(2)-C(8)-C(9)
C(5)-O(3)-C(6)
120.5(6)
126.1(7)
113.2(6)
126.8(7)
116.9(6)
116.3(7)
122.0(6)
120.9(6)
117.1(6)
120.9(5)
C(8)-N
C(9)-N
C(8′)-N′
C(9′)-N′
W-N(1)-C(8)
136.8(4)
123.2(6)
120.2(6)
116.5(6)
177.1(7)
121.8(6)
112.2(6)
117.5(6)
119.5(6)
112.5(6)
C(8)-N(2)-C(10)
C(8)-N(2)-C(11)
C(10)-N(2)-C(11)
W-C(1)-O(1)
C(3)-C(2)-C(6)
C(2)-C(3)-C(4)
C(3)-C(4)-C(5)
C(3)-C(4)-C(7)
C(5)-C(4)-C(7)
C(1)-W-C(2)
W-C(1)-O(1)
W-C(2)-O(2)
C(4)-C(3)-O(3)
C(4)-C(3)-O(4)
O(3)-C(3)-O(4)
C(3)-C(4)-C(5)
C(4)-C(5)-C(6)
C(5)-C(6)-C(7)
C(5)-C(6)-N
77.8(3)
176.5(6)
179.6(6)
125.2(6)
112.8(6)
121.9(6)
116.7(6)
122.4(6)
120.4(6)
119.7(6)
119.5(6)
122.5(6)
121.5(6)
114.8(6)
C(1′)-W′-C(2′)
W′-C(1′)-O(1′)
W′-C(2′)-O(2′)
C(4′)-C(3′)-O(3′)
C(4′)-C(3′)-O(4′)
O(3′)-C(3′)-O(4′)
C(3′)-C(4′)-C(5′)
C(4′)-C(5′)-C(6′)
C(5′)-C(6′)-C(7′)
C(5′)-C(6′)-N′
C(7′)-C(6′)-N′
C(6′)-N′-C(8′)
C(6′)-N′-C(9′)
C(8′)-N′-C(9′)
77.0(3)
177.9(7)
178.5(8)
124.8(6)
113.2(6)
122.0(6)
116.2(6)
122.1(6)
119.9(7)
120.0(7)
120.0(6)
121.6(7)
121.8(6)
116.5(7)
1
(mixture)): 2029 (s), 1933 (vs), 1695 (m), 1554 (s) ν(CdO). H
NMR (ppm, cis and trans forms were observed in CDCl3): cis
form, 8.76 (d, J H-H ) 12.0 Hz, 1H, dCH), 6.93 (d, J H-H ) 12.0
Hz, 1H, dCH), 5.60 (s, 5H, Cp), 3.67 (s, 3H, CH3); trans form,
9.19 (d, J H-H ) 19.5 Hz, 1H, dCH), 6.37 (d, J H-H ) 19.5 Hz,
1H, CH), 5.58 (s, 5H, Cp), 3.65 (s, 3H, CH3). MS (FAB, m/z):
420 (M+), 392 (M+ - CO), 364 (M+ - 2CO), 336 (M+ - 3CO).
The reaction of Cp(CO)3WH (0.05 g, 0.15 mmol) with methyl
propynoate (0.02 mL, 0.28 mmol) gave no product at room
temperature and upon heating gave 10 in only about 10%
yield. CpW(CO)3[η1-C(CO2Me)dCH(CO2Me] (11; 0.08 g) was
prepared similarly from the reaction of [CpW(CO)3]Na (0.45
g, 1.26 mmol) and DMAD (0.20 mL) in 65% yield. Spectro-
scopic data for 11 are as follows. IR (cm-1, THF): 2035 (s),
1940 (vs), 1740 (m), 1701 (m) ν(CdO). 1H NMR (CDCl3,
ppm): 6.54 (s, 1H, dCH), 5.56 (s, 5H, Cp), 3.73, 3.69 (s, 6H, 2
CH3). 13C NMR (CDCl3, ppm): 226.3, 210.0 (M-CO), 151.2
(R-C)), 178.2, 167.3 (CO), 132.6 (â-dCH), 93.1 (Cp), 51.6, 51.3
(2 CH3). MS (FAB, m/z): 478 (M+), 450 (M+ - CO), 422 (M+
- 2CO), 394 (M+ - 3CO). Anal. Calcd for C14H12O7W: C,
35.32; H, 2.54. Found: C, 35.44; H, 2.70.
C(7)-C(6)-N
C(6)-N-C(8)
C(6)-N-C(9)
C(8)-N-C(9)
Ta ble 4. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) of Cp (CO)(CH3CN)W[η3-CHCHC(Me)C-
(O)OC(O)] (9)
W-N
2.142(14)
1.950(17)
2.266(16)
2.113(16)
2.241(15)
1.103(23)
1.166(22)
1.433(25)
1.364(23)
1.47(3)
1.375(22)
1.42(3)
1.52(3)
1.365(25)
1.219(23)
1.400(23)
1.192(25)
W′-N1′
2.121(13)
1.947(19)
2.278(15)
2.174(14)
2.293(14)
1.134(23)
1.174(23)
1.48(3)
W-C(1)
W′-C(1′)
W-C(4)
W′-C(4′)
W-C(5)
W′-C(5′)
W-C(6)
W′-C(6′)
N-C(2)
N′-C(2′)
C(1)-O(1)
C(2)-C(3)
C(4)-C(5)
C(4)-C(8)
C(5)-C(6)
C(6)-C(7)
C(6)-C(9)
C(7)-O(2)
C(7)-O(3)
C(8)-O(2)
C(8)-O(4)
C(1′)-O(1′)
C(2′)-C(3′)
C(4′)-C(5′)
C(4′)-C(8′)
C(5′)-C(6′)
C(6′)-C(7′)
C(6′)-C(9′)
C(7′)-O(2′)
C(7′)-O(3′)
C(8′)-O(2′)
C(8′)-O(4′)
1.441(25)
1.44(3)
1.437(22)
1.466(25)
1.508(23)
1.398(23)
1.194(21)
1.393(23)
1.178(23)
Attem p ted P r ep a r a tion of 10 fr om Cp (CO)3WH. The
attempted reactions were carried out in NMR tubes and
monitored by NMR spectra. To a solution of Cp(CO)3WH (0.05
g) in 0.5 mL of CD3CN was added methyl propynoate (0.02
mL, 0.18 mmol) at room temperature, and the solution was
mixed thoroughly. After 2 h, no new material other than the
starting material was observed in the 1H NMR spectrum.
Then the solution was heated to reflux for 4 days to give a
complex mixture in which only ca. 10% of 10 was observed. If
the reaction was carried out in CDCl3, the major product was
Cp(CO)3WCl (about 75%) with only about 10% of the desired
product 10. The reaction of Cp(CO)3WH with ethyl propynoate
was similarly carried out first at room temperature. In CDCl3
for 3 days, the reaction yielded the Z product CpW(CO)3-
[CHdCHCO2Et] (16; 10%) and Cp(CO)3WCl (about 75%) along
with the starting material. Further heating led to decomposi-
tion of the starting material, and the reaction yielded a
complex mixture. In CD3CN, both E and Z products are
N-W-C(1)
W-N-C(2)
W-C(1)-O(1)
N-C(2)-C(3)
85.6(6)
N′-W′-C(1′)
W′-N′-C(2′)
W′-C(1′)-O(1′)
N′-C(2′)-C(3′)
86.1(6)
176.5(13)
171.2(14)
176.2(20)
117.8(14)
119.6(15)
116.0(16)
122.7(15)
112.4(14)
120.6(16)
125.6(19)
113.6(18)
116.6(15)
126.2(18)
117.1(18)
121.0(14)
173.9(14)
175.2(12)
179.4(20)
123.6(14)
110.8(13)
120.4(14)
118.9(14)
113.5(14)
118.1(14)
127.1(18)
114.7(16)
115.6(15)
127.0(18)
117.4(17)
122.9(13)
C(5)-C(4)-C(8)
C(4)-C(5)-C(6)
C(5)-C(6)-C(7)
C(5)-C(6)-C(9)
C(7)-C(6)-C(9)
C(6)-C(7)-O(2)
C(6)-C(7)-O(3)
O(2)-C(7)-O(3)
C(4)-C(8)-O(2)
C(4)-C(8)-O(4)
O(2)-C(8)-O(4)
C(7)-O(2)-C(8)
C(5′)-C(4′)-C(8′)
C(4′)-C(5′)-C(6′)
C(5′)-C(6′)-C(7′)
C(5′)-C(6′)-C(9′)
C(7′)-C(6′)-C(9′)
C(6′)-C(7′)-O(2′)
C(6′)-C(7′)-O(3′)
O(2′)-C(7′)-O(3′)
C(4′)-C(8′)-O(2′)
C(4′)-C(8′)-O(4′)
O(2′)-C(8′)-O(4′)
C(7′)-O(2′)-C(8′)
observed. Spectroscopic data for 16 are as follows. IR (cm-1
,
THF (mixture)): 2027 (s), 1942 (vs), 1685 (m), 1550 (s) ν(CdO).
at 0 °C, and the reaction mixture was stirred for 24 h while it
was warmed to room temperature. Then the solvent was
removed under vacuum, and the residue was extracted with
2 × 10 mL of ether. The extract was filtered and evaporated
to dryness to give the yellow product 10 (0.07 g mixture of
cis/trans (4/1) isomers, 40%) after recrystallization from hex-
ane. Spectroscopic data for 10 are as follows. IR (cm-1, THF
1H NMR (ppm, cis and trans forms were observed in CDCl3):
cis form, 8.69 (d, J H-H ) 12.0 Hz, 1H, dCH), 6.93 (d, J H-H
)
12.0 Hz, 1H, dCH), 5.60 (s, 5H, Cp), 4.10 (q, J H-H ) 7.1 Hz,
OCH2), 1.18 (t, J H-H ) 7.1 Hz, 3H, CH3); trans form, 8.97 (d,
J H-H ) 16.0 Hz, 1H, dCH), 6.80 (d, J H-H ) 16.0 Hz, 1H, CH),
5.61 (s, 5H, Cp), 4.10 (q, J H-H ) 7.1 Hz, OCH2), 1.18 (t, J H-H

4644 Organometallics, Vol. 16, No. 21, 1997
Lee et al.
) 7.1 Hz, 3H, CH3). MS (FAB, m/z): 434 (M+), 406 (M+
CO), 378 (M+ - 2CO), 360 (M+ - 3CO).
P h otolysis of 11. Complex 11 (0.08 g, 0.17 mmol) was
dissolved in C6D6, and the solution was irradiated with a 450
W Hg lamp at room temperature for 30 min. The 1H NMR
-
latter by an empirical method using an ω scan. The structures
were solved by Patterson methods and refined using the
NRCVAX programs. All non-hydrogen atoms were refined
anisotropically during the final least-squares cycles, and all
hydrogen atoms were included at geometrically calculated
positions at a fixed distance of 0.96 Å from their parent atom.
Selected bond distances and angles are listed in Tables 2-5
for 4, 6, 9, and 14, respectively.
spectra indicated formation of Cp(CO)2W[C(CO2Me)dCH(C(O)-
OMe)] (12) as the single observable product. The solvent was
removed under vacuum, and the product was extracted with
2 × 20 mL of ether. After filtration, ether was removed and
complex 12 (0.055 g, 0.12 mmol) was isolated after recrystal-
lization from hexane in 72% yield. Spectroscopic data for 12
are as follows. IR (cm-1, KBr): 1948 (vs), 1873 (s), 1701 (m),
1534 (m) ν(CdO). 1H NMR (CDCl3, ppm): 6.35 (s, 1H, dCH),
5.51 (s, 5H, Cp), 3.89, 3.82 (s, 6H, 2 CH3). 13C NMR (CDCl3):
218.6 (M-CO); 185.3 (R-Cd), 181.3, 176.8 (CO), 114.1 (â-dCH),
92.6 (Cp), 54.2, 51.7 (2 CH3). MS (FAB, m/z): 450 (M+), 422
(M+ - CO), 394 (M+ - 3CO). Anal. Calcd for C13H12O6W: C,
34.85; H, 2.70. Found: C, 34.92; H, 2.76.
Ack n ow led gm en t. We are grateful for financial
support of this work by the National Science Council of
the Republic of China.
Su p p or tin g In for m a tion Ava ila ble: Details of the struc-
tural determination for complexes 4, 6, 9, and 14, including
tables of fractional coordinates, anisotropic thermal param-
eters, and all bond distances and angles and text giving
synthetic details and characterization data for 5 and 11 (13
pages). Ordering information is given on any current mast-
head page.
X-r a y Str u ctu r e Deter m in a tion . Many of the details of
the crystal structure analyses carried out on 4, 6, 9, and 14
are in Table 1. Data were collected on a CAD4 automatic four-
circle diffractometer at 297 K. Corrections for Lorentz-
polarization and X-ray absorption effects were applied, the
OM970431Z