Organic syntheses via transition-metal complexes. 99.1 cyclopentadiene annelation to enolizable cyclic ketones via (1-alkynyl)carbene complexes (M = Cr, W)

Article abstract of DOI:10.1021/om9810394

The procedure for a metal-mediated cyclopentadiene annelation to enolizable cycloalkanones is described. Its key step is based on the cyclization of a 1-metalla-1,3,5-hexatriene intermediate, which is generated from the 1-metalla-1,5-hexadien-3-yne (CO)₅M=C(OEt)C≡ CC(～)=CH(～) (3; M = Cr, W) precursor. Addition of secondary amines 4a,b to [2-(1-cyclopentenyl)ethynyl]carbene complexes 3a,b (M = W, Cr) affords the 4-amino-1-metalla-1,3,5-hexatrienes (3E)-5a-d, which cyclize spontaneously to the η(C,M)-cyclopentadiene complexes 6a-d. The ring closure is highly stereoselective and involves an anti addition (!) of the M=C bond to the terminal C=C bond of the 1-metalla-1,3,5-hexatriene unit. Ligand displacement from compound 6a is achieved by protonation to give an iminium salt 7a. Addition of aniline to compounds 3a,b yields 4-(NH-amino)-1-metalla-1,3,5-hexatrienes (3Z)-10a,b, which subsequently cyclize to cyclopentenimine(N,M) complexes syn-11a,b and anti-11a,b and finally afford the cyclopentenimine 12 by oxidative ligand disengagement. Addition of secondary phosphanes 13a,b to compound 3a produces a mixture of the isomeric cyclopentadiene(P,W)-tungsten complexes anti-14a,b, anti-15a,b, and anti-16b. X-ray structure analyses are reported of compounds (3E)-5a, 6c, anti-11a, anti-16b, and anti-17a.

Full text of DOI:10.1021/om9810394

Organometallics 1999, 18, 1369-1380
1369
Articles
Or ga n ic Syn th eses via Tr a n sition -Meta l Com p lexes. 99.1
Cyclop en ta d ien e An n ela tion to En oliza ble Cyclic
Keton es via (1-Alk yn yl)ca r ben e Com p lexes (M ) Cr , W)†
Rudolf Aumann,* Roland Fro¨hlich,‡ J o¨rg Prigge,‡ and Oliver Meyer‡
Organisch-Chemisches Institut der Universita¨t Mu¨nster, Corrensstrasse 40,
D-48149 Mu¨nster, Germany
Received December 22, 1998
The procedure for a metal-mediated cyclopentadiene annelation to enolizable cyclo-
alkanones is described. Its key step is based on the cyclization of a 1-metalla-1,3,5-hexatriene
intermediate, which is generated from the 1-metalla-1,5-hexadien-3-yne (CO)5MdC(OEt)Ct
CC(∼)dCH(∼) (3; M ) Cr, W) precursor. Addition of secondary amines 4a ,b to [2-(1-
cyclopentenyl)ethynyl]carbene complexes 3a ,b (M ) W, Cr) affords the 4-amino-1-metalla-
1,3,5-hexatrienes (3E)-5a -d , which cyclize spontaneously to the η1(C,M)-cyclopentadiene
complexes 6a -d . The ring closure is highly stereoselective and involves an anti addition (!)
of the MdC bond to the terminal CdC bond of the 1-metalla-1,3,5-hexatriene unit. Ligand
displacement from compound 6a is achieved by protonation to give an iminium salt 7a .
Addition of aniline to compounds 3a ,b yields 4-(NH-amino)-1-metalla-1,3,5-hexatrienes (3Z)-
10a ,b, which subsequently cyclize to cyclopentenimine(N,M) complexes syn-11a ,b and anti-
11a ,b and finally afford the cyclopentenimine 12 by oxidative ligand disengagement. Addition
of secondary phosphanes 13a ,b to compound 3a produces a mixture of the isomeric
cyclopentadiene(P,W)-tungsten complexes anti-14a ,b, anti-15a ,b, and anti-16b. X-ray
structure analyses are reported of compounds (3E)-5a , 6c, anti-11a , anti-16b, and anti-
17a .
(1-Alkynyl)carbene complexes (CO)5MdC(OEt)CtCR
(M ) W, Cr) have been applied as stoichiometric
reagents in a number of high-yield transformations of
potential usefulness to organic synthesis.2 It has been
shown recently that cyclopentadienes can be generated
in a [3 + 2] fashion from reaction of (1-alkynyl)carbene
complexes with cycloalkenylamines (∼)CHdC(∼)NR2 in
solvents such as dichloromethane. 6-Amino-1-metalla-
1,3,5-hexatrienes (CO)5MdC(OEt)CHdC(Ph)C(∼)dC(∼)-
(NR2) (M ) W, Cr) were found to be key intermediates
in these transformations ()“alkene route to cyclopen-
tadienes”).3 An alternate route to the formation of
cyclopentadienes by [3 + 2] cycloaddition is based upon
the reaction of the (2-amino-1-alkenyl)carbene-chro-
mium complexes ()4-amino-1-chroma-1,3-butadienes)
(CO)5CrdC(OEt)CHdC(R′)NR2 with alkynes RCtCH,
and the 6-amino-1-chroma-1,3,5-hexatrienes (CO)5Crd
C(R)CHdC(OEt)CHdC(R′)NR2 (generated by insertion
of the CtC into the CrdC bond) are thought to be key
intermediates ()“alkyne route to cyclopentadienes”).2a
A strong driving force for the cyclization of 1-metalla-
1,3,5-hexatrienes to cyclopentadienes is provided by
amino substituents and not only 6-amino- (vide supra)
but also 2-amino- and 4-amino substituents were found
to enhance this reaction. Examples of the latter type
comprise cyclization both of the 2-amino-1-tungsta-1,3,5-
hexatriene (CO)5WdC(NEt2)C(Me)dC(OEt)CHdCHPh
(generated by insertion of the 1-aminoalkyne Et2NCt
CMe into the WdC bond of the 1-tungsta-1,3-butadiene
(CO)5WdC(OEt)CHdCHPh)4a as well as the 4-amino-
1-tungsta-1,3,5-hexatriene (CO)5WdC(OEt)CHdC(NEt2)-
C(Me)dCHPh (generated by insertion of the 1-ami-
noalkyne Et2NCtCMe into the CdC bond of the 1-tung-
sta-1,3-butadiene (CO)5WdC(OEt)CHdCHPh)4b to η1-
cyclopentadiene complexes under very mild conditions
at 20 °C.4b It should be noted that, to date, experimental
proof of cyclopentadiene formation by cyclization of
1-metalla-1,3,5-hexatrienes is limited to the foremen-
tioned 2-amino, 4-amino, and 6-amino derivatives.
We now wish to report on a newly developed metal-
mediated cyclopentadiene annelation to enolizable cy-
† Dedicated to Prof. H. Werner on the occasion of his 65th birthday.
‡ X-ray structure analyses.
(1) For part 98 of this series see: Aumann, R.; Ko¨ssmeier, M.; J a¨ntti,
A. Synlett 1998, 1120.
(2) For recent reviews see: (a) de Meijere, A. Pure Appl. Chem. 1996,
68, 61. (b) Aumann, R.; Nienaber, H. Adv. Organomet. Chem. 1997,
41, 161.
(3) (a) Aumann, R.; Roths, K.; Grehl, M. Synlett 1993, 669. (b)
Aumann, R.; Ko¨ssmeier, M.; Roths, K.; Fro¨hlich, R. Synlett 1994, 1041.
(c) Meyer, A. G.; Aumann, R. Synlett 1995, 1011. (d) Aumann, R.;
Roths, K.; J asper, B.; Fro¨hlich, R. Organometallics 1996, 15, 1257. (e)
Aumann, R.; Ko¨ssmeier, M.; Zippel, F. Synlett 1997, 621. (f) Aumann,
R.; Meyer, A. G.; Fro¨hlich, R. Organometallics 1996, 15, 5018.
(4) (a) Aumann, R.; Heinen, H., Hinterding, P.; Stra¨ter, N.; Krebs,
B. Chem. Ber. 1991, 124, 1229. (b) Aumann, R.; Heinen, H.; Dartmann,
M.; Krebs, B. Chem. Ber. 1991, 124, 2343.
10.1021/om9810394 CCC: $18.00 © 1999 American Chemical Society
Publication on Web 03/13/1999

1370 Organometallics, Vol. 18, No. 8, 1999
Aumann et al.
Sch em e 1. P r in cip le of th e Meta l-Med ia ted
Cyclop en ta d ien e An n ela tion to En oliza ble
Cycloa lk a n on es in Over a ll [2 + 2 + 1] F a sh ion
Sch em e 3. Gen er a tion of
(3E)-4-Am in o-1-m eta lla -1,3,5-tr ien es 5 a n d
η1-Cyclop en ta d ien e Com p lexes 6 by Ad d ition of
Secon d a r y Am in es to (1-Alk yn yl)ca r ben e
Com p lexes 3a ,ba
Sch em e 2. 1-Meta lla -1,5-h exa d ien -3-yn es 3 fr om
Cycloa lk a n on es
a
Isolated chemical yields.
high stereoselectivity.2b,7 On the basis of these results,
it could be predicted that (3E)-4-amino-1-metallatrienes
5 would be generated by addition of secondary amines
to [2-(1-cyclopentenyl)ethynyl]carbene complexes of chro-
mium and tungsten (3a ,b; Scheme 3), and (3Z)-4-amino-
1-metallatrienes 10 of opposite stereochemistry by
addition of primary arylamines (Scheme 7). We subse-
quently present details of the formation of compounds
3 and 10, as well as its cyclization reactions to cyclo-
pentadiene complexes and cyclopentenimine complexes,
respectively.
a
Isolated chemical yields.
cloalkanones involving the successive addition of acety-
lene, carbon monoxide, an alkyl group, and a protic
nucleophile NuH (Scheme 1). The key step of this
reaction sequence is based on the cyclization of a
1-metalla-1,3,5-hexatriene intermediate, which is gen-
erated by addition of a protic nucleophile NuH to the
CtC bond of a 1-metalla-1,5-hexadien-3-yne precursor
(CO)5MdC(OEt)CtCC(∼)dCH(∼) (M ) Cr, W). It will
be demonstrated that amino as well as phosphanyl
substituents at the 4-position of the 1-metalla-1,3,5-
hexatriene are well-suited to trigger the π-cyclization
of such compounds under mild conditions.
(3E)-4-Am in o-1-m eta lla -1,3,5-h exa tr ien es 5 a n d
η1-Am in ocyclop en ta d ien e Com p lexes 6
(3E)-4-Amino-1-metalla-1,3,5-hexatrienes (3E)-5a -d
are obtained as yellow crystals, if secondary amines 4a ,b
[HNMe2 and (2S)-(methoxymethyl)pyrrolidine] are added
to [2-(1-cyclopentenyl)ethinyl]carbene complexes 3a ,b
(M ) W, Cr) in diethyl ether at 0 °C (Scheme 3). The
reaction is fast, and the point of equivalency is visually
recognized by a color change from dark brown to bright
yellow. If isolation of compounds (3E)-5 is intended,
solvent must be removed immediately, since compounds
(3E)-5a -d are stable in the solid state but undergo ring
closure in solution at ambient temperature to give the
zwitterionic η1-cyclopentadiene complexes 6a -d (vide
infra). Recrystallization of compounds 5 from diethyl
ether may be achieved with minor loss, if carried out
quickly at low temperature.
The 13C NMR chemical shifts of the MdC group (e.g.
tungsten complex (3E)-5a , δ 268.5; chromium complex
(3E)-5b, δ 287.1) as well as of the C6-N unit (e.g. (3E)-
5a , δ 157.2; (3E)-5b, 154.2) of compounds (3E)-5 are
typically observed with planar and highly polarized
enamino carbene complexes (OC)5MdC(OEt)CHdC-
[2-(1-Alk en yl)eth yn yl]ca r ben e Com p lexes
()1-Meta lla -1,5-h exa d ien -3-yn es)
The first part of our investigation took aim at the
preparation of 1-metalla-1,5-hexadien-3-ynes (CO)5Md
C(OEt)CtCC(∼)dCH(∼) (3a -d ; M ) Cr, W) from
cycloalkenones 1a -c. Our procedure is straightforward
and involves formation of 1-ethynylcycloalkenes 2a -c
from ketones 1a -c and acetylene via carbinoles.5 Com-
pounds 2 are finally transformed into the (1-alkynyl)-
carbene complexes 3 by the Fischer route (Scheme 2).6
Reaction of (1-alkynyl)carbene complexes (CO)5Md
C(OEt)CtCR (M ) Cr, W; R ) aryl, alkyl) with
secondary and primary amines, respectively, was previ-
ously shown to yield 4-amino-1-metalla-1,3-dienes of
opposite configurations, 3E and 3Z, respectively, with
(5) Brandsma, L. Preparative Acetylenic Chemistry, 2nd ed.; Elsevi-
er: Amsterdam, 1998; p 204.
(6) (a) Fischer, E. O.; Kreissl, F. R. J . Organomet. Chem. 1972, 35,
C47. (b) Fischer, E. O.; Kalder, H. J . J . Organomet. Chem. 1977, 131,
57. (c) Fischer, E. O.; Schubert, U.; Kleine, W.; Fischer, H. Inorg. Synth.
1979, 19, 164.
(7) (a) Duetsch, M.; Stein, F.; Lackmann, R.; Pohl, E.; Herbst-Irmer,
R.; de Meijere, A. Chem. Ber. 1992, 125, 2051. (b) Aumann, R.;
Hinterding, P. Chem. Ber. 1993, 126, 421.

Cyclopentadiene Annelation to Cyclic Ketones
Organometallics, Vol. 18, No. 8, 1999 1371
Sch em e 4. Degen er a te Rea r r a n gem en ts, (1) a n d
(2), Resp ectively, of Meta lla tr ien e (3E)-5a a
F igu r e 1. Molecular structure of 4-amino-tungsta-1,3,5-
hexatriene species (3E)-5a . Selected bond lengths (Å) and
angles (deg): W-C4 ) 2.281(6), C4-O3 ) 1.336(8), C4-
C5 ) 1.391(9), C5-C6 ) 1.392(9), C6-N7 ) 1.346(9), C6-
C60 ) 1.490(9), C60-C61 ) 1.443(11), C60-C64 ) 1.373-
(12); W-C4-O3 ) 127.7(5), W-C4-C5 ) 119.2(4), O3-
C4-C5 ) 113.1(6), C4-C5-C6 ) 129.1(6), C5-C6-N7 )
120.9(6), C5-C6-C60 ) 123.4(6), C60-C6-N7 ) 115.7-
(6), C6-C60-C61 ) 123.2(7), C6-C60-C64 ) 124.0(7),
C61-C60-C64 ) 112.7(7), C60-C61-C62 ) 106.1(7),
C60-C64-C63 ) 108.6(8), C10-W-C4-C5 ) 136.7(6).
a
∆Gq values are estimated from NMR measurements at
different temperatures.
(NR2)∼ of 3E configuration7 in a range clearly distinct
from (nonplanar) torquo-carbiminium carbonylmeta-
lates -(OC)5M-C(OEt)dCHC(dN+R2)∼.8 The (planar)
enamine structure of compounds (E)-5 is confirmed in
the X-ray structure analysis of compound (3E)-5a by the
dihedral angles C4-C5-C6-N7 ) -173.8(8)°, C5-C6-
N7-C8 ) -174.6(9)°, and W-C4-C5-C6 ) -176.7-
(6)° as well as by the pattern of nonalternating bond
distances C4-C5 ) 1.391(9) Å, C5-C6 ) 1.392(9) Å,
and C6-N7 ) 1.346(9) Å within the ligand backbone,
which indicates strong π-delocalization (Figure 1).
The methylene protons of (3E)-5a are diastereotopic
due to chirality induced by distortion of the 1-cyclopen-
tenyl group from planarity by C5-C6-C60-C64 ) 86.3-
(10)° (Figure 1). A sharp set of clearly separated signals
Ch a r t 1. Alter n a te (Exp er im en ta lly Un obser ved )
Coor d in a tion Mod es of Cyclop en ta d ien e
Com p lexes 6
5c and (3E)-5c′ resulting from different configurations
of the C3-N bond. Two more sets of signals, which
appear at -40 °C, are attributed to right- and left-
handed spiral structures, respectively, of the 1-metal-
lahexatriene (3E)-5c (analogous to the structures (3E)-
5a and (3E)-5a ′′ in Scheme 4). 4-Amino-1-metalla-
hexatrienes (3E)-5 are stable in the solid state but
undergo smooth rearrangement in solution within a few
hours at ambient temperature to zwitterionic η1-cyclo-
pentadiene complexes 6. The reaction can be monitored
by NMR spectra.
1
is observed in the H NMR spectra of compound (3E)-
5a below -40 °C (CDCl3, 600 MHz), but line broadening
caused by rapid exchange processes is found above this
temperature. Two degenerate reactions (Scheme 4; (1)
and (2), respectively) can be distinguished from different
activation enthalpies at the coalescence temperatures.
∆Gq ) ca. 60 kJ /mol was found for the interconversion
(1) of structures (3E)-5a and (3E)-5a ′ (leading to an
exchange of the magnetic environments of the N-CH3
groups); ∆Gq ) ca. 51 kJ /mol was determined for the
interconversion (2) of structures (3E)-5a and (3E)-5a ′′
(involving an exchange of the magnetic environments
of the diastereotopic methylene protons OCH2 as well
as 3′-H2, 4′-H2, and 5′-H2 of the cyclopentene ring)
(Scheme 4).
It should be noted that a zwitterionic η1 coordination
of the bridgehead R-carbon atom of the aminocyclopen-
tadiene unit to the W(CO)5 group (Scheme 3) is favored
over the coordination mode B of the nitrogen atom of
the NR2 group or a η2 coordination modes C and D,
respectively, of a CdC bond (Chart 1).
The η1 coordination4b in cyclopentadiene complexes
6 is indicated in the 13C NMR spectrum by a high-field
shift of the M-C unit (6c, W-C δ 50.6; 6d , Cr-C δ 54.3)
and a low-field shift of the CdN unit (6c, δ 190.3; 6d , δ
187.8). The carbiminium carbonylmetalate structure is
further documented in the X-ray structure analysis of
compound 6c by the long distance of the W-C single
bond, W1-C1 ) 2.43(2) Å, and the short distance C8-
N9 ) 1.37(3) Å of the C-N double bond (Figure 2).9
The ring closure of the 4-amino-1-metalla-1,3,5-
hexatriene (3E)-5c to the η1-cyclopentadiene complex
Introduction of a chiral amine substituent into the
1-metalla-1,3,5-hexatriene (3E)-5 leads to generation of
diastereomers. Four diastereomers were found to be
present in the solution of (3E)-5c, in which (2S)-
(methoxymethyl)pyrrolidine (4b) is attached to the
metallatriene unit. These are rapidly interconverting on
the NMR time scale, but two sets of signals in a ratio
1
of ca. 1:2 can be distinguished in the H NMR spectrum
(CDCl3, 600 MHz) at -10 °C for the stereoisomers (3E)-
(8) Aumann, R.; Roths, K.; Fro¨hlich, R. Organometallics 1997, 16,
5893.
(9) Structural data for a vinylogous carbiminium carbonyltungstate
are reported in ref 4b.

1372 Organometallics, Vol. 18, No. 8, 1999
Aumann et al.
Sch em e 6. Liga n d Disp la cem en t fr om
η1-Cyclop en ta d ien e Com p lexes 6 by P r oton a tion
F igu r e 2. Molecular structure of the dihydropentalene
carbiminium carbonylmetalate 6c. Selected bond lengths
(Å) and angles (deg): W1-C1 ) 2.43(2), C1-C2 ) 1.59(2),
C1-C5 ) 1.55(3), C1-C8 ) 1.37(3), C2-C3 ) 1.51(4), C3-
C4 ) 1.37(4), C4-C5 ) 1.58(3), C5-C6 ) 1.54(3), C6-O
) 1.32(3), C6-C7 ) 1.33(3), C7-C8 ) 1.50(2), C8-N9 )
1.37(3), N9-C10 ) 1.48(2); W-C1-C2 ) 116(2), W-C1-
C8 ) 106.4(12), W-C5-C1 ) 108.7(13), C2-C1-C5 ) 102-
(2), C2-C1-C8 ) 117(2), C5-C1-C8 ) 105(2), C1-C8-
N9 ) 128(2).
reaction path outlined in Scheme 6 does not imply an
intermediate disengagement of a carbonyl ligand from
the W(CO)5 group, in line with the exceedingly mild
reaction conditions of 20 °C required for the π-cycliza-
tion to proceed. Chelation of a pentacarbonyl-1-tungsta-
1,3,5-hexatriene by elimination of carbon monoxide to
a (5,6-η)-tetracarbonyl-1-tungsta-1,3,5-hexatriene (char-
acterized by an X-ray structure analysis)3e was indeed
observed at temperatures above 90 °C.
Sch em e 5. Cycliza tion of 1-Meta lla tr ien es by a n ti
Ad d ition of th e MdC Bon d to th e 5,6-CdC Bon d
Even though facile ligand elimination is indicated in
the mass spectrum of compound 6a by the base peak
m/e 193 (100%) and the strong fragment peak m/e 165
(90%) resulting from elimination of ethylene, generation
of cyclopentadiene 8a from complex 6a could not, to
date, be achieved on a preparative scale, supposedly due
to the low stability of compound 8a on one side and the
high stability of complex 6a on the other side. Com-
pounds 6a -d do not exhibit the reactivity expected of
an olefin π-complex but rather that of a σ-complex.
Thus, ligand displacement from compound 6a is not
achieved, e.g., with pyridine at 70 °C. Extension of the
reaction time to 5 h at 70 °C results in partial decom-
position of compound 6a and production of cyclopen-
tenone 9a (possibly by elimination of ethylene?) and
W(CO)6. On the other hand, addition of HBF4 in diethyl
ether to compound 6a yields the iminium salt 7a in a
smooth reaction together with W(CO)6. Addition of 10%
KOH/90% H2O to compound 7a does not produce the
cyclopentadiene 8a but the cyclopentenone 9a instead
(Scheme 6).
(2′′S,3aR,6aS′)-6c involves an anti addition of the Md
C bond to the terminal CdC bond (Scheme 5). This
stereochemical course is not restricted to the specific
geometrical requirements of the bicyclo[3.3.0]octene ring
skeleton; it was previously observed also with monocy-
clic systems.4b An anti-addition mode for this ring
closure is quite unexpected, considering the fact that
metallacyclohexenes or (CO)4M chelate complexes would
normally be anticipated as intermediates. On the basis
of the reasonable assumption that the overall reaction
is intramolecular, it can be stated that neither a
1-metallacyclohexa-2,4-diene nor a cyclic (CO)4W com-
plex ()(5,6-η)-1-metalla-1,3,5-hexatriene) would be an
intermediate en route to the cyclopentadiene complex,
since either of these structures should necessarily result
in syn addition of the MdC bond to the terminal CdC
bond. To meet the stereochemical requirements for the
ring closure, it is suggested that the zwitterionic species
F is formed initially, from which the cyclopentadiene
complex (2′′S,3aR,6aS′)-6c is generated by migration of
the W(CO)5 unit, possibly through the intermediate G.
The stereocontrol of the reaction is based on the as-
sumption that formation of an exo-W(CO)5 group in the
zwitterion F should be kinetically strongly favored over
formation of the endo derivative E. Moreover, the
(Z)-4-(NH-Am in o)-1-m eta lla -1,3,5-h exa tr ien es 10,
Cyclop en ten im in e Com p lexes 11, a n d
Cyclop en ten im in e 12
Addition of primary arylamines ArNH2 to a (1-
alkynyl)carbene complex, e.g. (CO)5MdC(OEt)CtCPh
(M ) W, Cr), was shown to afford 4-(arylamino)-1-
metalla-1,3-butadienes (CO)5MdC(OEt)CHdC(NHAr)-
Ph.7 The reaction is highly regioselective and also
stereoselective with respect to the formation of 3Z
stereoisomers, which seem to be stabilized by an O‚‚‚
H-N hydrogen bridge.10 In line with expectation, (3Z)-
4-NH-amino-1-metalla-1,3,5-trienes (3Z)-10a ,b could be
(10) Aumann, R.; Roths, K.; Ko¨ssmeier, M.; Fro¨hlich, R. J . Orga-
nomet. Chem. 1998, 556, 119.

Cyclopentadiene Annelation to Cyclic Ketones
Organometallics, Vol. 18, No. 8, 1999 1373
Sch em e 7. Gen er a tion of
4-(NH-Am in o)-1-m eta lla -1,3,5-h exa tr ien es (3Z)-10
a n d Its Su p p osed Cou r se of Cycliza tion
F igu r e 3. Molecular structure of the imine complex anti-
11a . Selected bond lengths (Å) and angles (deg): W-N12
) 2.276(3), N12-C10 ) 1.296(5), N12-C120 ) 1.452(5),
C10-C9 ) 1.528(5), C9-C8 ) 1.547(6), C9-C5 ) 1.559-
(5), C8-C7 ) 1.526(6), C7-C6 ) 1.528(6), C6-C5 ) 1.520-
(6), C5-C4 ) 1.503(5), C4-C11 ) 1.348(5), C4-O3 )
1.327(5), C11-C10 ) 1.434(5); W-N12-C10 ) 128.3(2),
W-N12-C120 ) 114.4(2), C120-N12-C10 ) 117.1(3),
N12-C10-C9 ) 126.0(3), N12-C10-C11 ) 125.0(3),
C11-C10-C9 ) 109.1(3), C10-C9-C8 ) 113.2(3), C10-
C9-C5 ) 104.3(3), C5-C9-C8 ) 104.2(3), C9-C8-C7 )
105.4(3), C8-C7-C6 ) 102.4(4), C7-C6-C5 ) 103.6(3),
C6-C5-C4 ) 112.8(3), C6-C5-C9 ) 106.7(3), C9-C5-
C4 ) 102.7(3), C5-C4-O3 ) 115.7(3), C5-C4-C11 )
114.1(3), O3-C4-C11 ) 130.2(4), C4-C11-C10 ) 109.4-
(3).
Sch em e 8. Cyclop en ten im in e Com p lexes:
Gen er a tion , syn /a n ti Isom er iza tion , a n d Meta l
Disen ga gem en t
syn-11b and anti-11b (but not from the corresponding
tungsten complexes) by chromatography on silica gel in
the presence of air.
The structures of compounds 11 and 12 are based on
spectroscopic evidence, as well as on an X-ray structure
analysis of anti-11a (Figure 3).
generated with high stereoselectivity by addition of
aniline to [2-(1-cyclopentenyl)ethynyl]carbene complexes
3a ,b (M ) W, Cr) in diethyl ether at 0 °C (Scheme 7).
Though 3Z stereoisomers are isolated as the only
products, it could be demonstrated by spin saturation
transfer NMR techniques that 3E stereoisomers will be
present in solution, although only in small equilibrium
concentrations.10
4-(NH-Amino)-1-metallahexatrienes (3Z)-10 undergo
clean cyclization in solution at 50 °C within 4 h to give
a mixture of the cyclopentenimine complexes syn-11 and
anti-11 (Scheme 8). The products could be separated by
column chromatography on silica gel, and it was dem-
onstrated by NMR spectra that the compounds anti-
11a ,b are generated from the compounds syn-11a ,b at
50 °C. Cyclization of 4-(NH-amino)-1-metalla-1,3,5-
hexatrienes (3Z)-10a ,b to compounds 11a ,b is assumed
to follow the route outlined in Scheme 7. The reaction
path suggested is similar to that depicted for the
generation of compounds (3E)-5c in Scheme 5, except
that zwitterionic carbiminium metalates H are assumed
to be unstable and undergo proton transfer from the
dNH+ nitrogen atom to the R-carbon atom. Coordina-
tion of the imino function to the M(CO)5 group appears
to stereoselectively produce initially the syn-compounds
11 (Scheme 8).
(3E)-4-P h osp h a n yl-1-m eta lla -1,3,5-h exa tr ien es
a n d P h osp h a n ylcyclop en ta d ien e Com p lexes
Addition of secondary phosphanes to the (1-alkynyl)-
carbene complexes (CO)5MdC(OEt)CtCPh (M ) W, Cr)
was previously shown to afford the (3E)-4-phosphanyl-
1-metalla-1,3-butadienes (CO)5MdC(OEt)CHdC(PR2)-
Ph, which were isolated and characterized by X-ray
structure analyses.11 Reaction of the tungsten compound
3a with secondary phosphanes 13a ,b was found to be
fast even at 0 °C and yielded mixtures of phosphanyl-
cyclopentadiene complexes anti-14-16 (Schemes 9 and
10), which are coordinated through the phosphorus
atom. Reaction intermediates, e.g. compounds I and J
(Scheme 9) could not be detected in this case.11
The overall yield of phosphanylcyclopentadiene com-
plexes is high, but the relative amount of isomers anti-
14-16 was found to depend on the details of the
preparation, since these compounds are interconverted
by 1,5-hydrogen shifts as outlined in Scheme 10.
The tungsten compounds anti-14a ,b, anti-15a ,b, and
anti-16b were separated by chromatography on silica
gel, under which conditions compounds anti-17a ,b are
generated in small amounts by hydrolysis of the enol
ether unit. The structures of the phosphanyl compounds
could be easily derived from the NMR spectra. The anti
configuration is assigned on the basis of a low-field shift
Cyclopentenimine complexes 11 prove quite stable
toward attempted ligand displacement with triphen-
ylphosphine or pyridine, but the (metal-free) imine 12
is readily generated from both the chromium complexes
(11) Aumann, R.; J asper, B.; La¨ge, M.; Krebs, B. Chem. Ber. 1994,
127, 2475.

1374 Organometallics, Vol. 18, No. 8, 1999
Aumann et al.
Sch em e 9. P h osp h a n ylcyclop en ta d ien e Com p lexes
F igu r e 4. Molecular structure of the dihydropentalene
phosphine complex anti-16b. Selected bond lengths (Å) and
angles (deg): W-P ) 2.5604(10), P-C31 ) 1.858(4),
P-C41 ) 1.846(4), P-C6 ) 1.812(4), C6-C7 ) 1.348(5),
C7-C8 ) 1.491(6), C7-C11 ) 1.458(6), C8-C9 ) 1.533-
(6), C9-C10 ) 1.517(7), C10-C11 ) 1.514(6), C11-C4 )
1.324(6), C4-O3 ) 1.354(5), C4-C5 ) 1.504(5), C5-C6 )
1.516(5); W-P-C31 ) 114.51(13), W-P-C41 ) 114.80-
(12), W-P-C6 ) 115.22(13), C31-P-C41 ) 103.26(17),
C31-W-C6 ) 103.47(17), C41-P-C6 ) 104.08(18), P-C6-
C5 ) 122.3(3), P-C6-C7 ) 130.8(3), C5-C6-C7 ) 106.9-
(3), C6-C7-C8 ) 139.3(4), C6-C7-C11 ) 111.2(4), C11-
C7-C8 ) 109.5(4), C7-C8-C9 ) 105.5(4), C8-C9-C10
) 108.5(4), C9-C10-C11 ) 104.6(4), C10-C11-C7 )
110.0(4), C10-C11-C4 ) 141.3(4), C7-C11-C4 ) 108.7-
(4), C11-C4-O3 ) 134.0(4), C11-C4-C5 ) 109.8(4), O3-
C4-C5 ) 116.2(4), C4-C5-C6 ) 103.4(3).
Sch em e 10. P h osp h a n ylcyclop en ta d ien e
Com p lexes: Isom er iza tion by 1,5-H Sh ifts a n d
Hyd r olysis
F igu r e 5. Molecular structure of the dihydropentalene
phosphine complex anti-17a . Selected bond lengths (Å) and
angles (deg): W-P ) 2.6086(11), P-C6 ) 1.887(4), P-C7
) 1.907(4), P-C8 ) 1.852(4), C8-C9 ) 1.547(5), C9-C10
) 1.519(6), C9-C13 ) 1.543(6), C10-C11 ) 1.523(7), C11-
C12 ) 1.511(8), C12-C13 ) 1.535(7), C13-C14 ) 1.519-
(6), C14-O14 ) 1.215(5), C14-C15 ) 1.463(6), C8-C15
) 1.328(6); W-P-C6 ) 112.5(2), W-P-C7 ) 116.58(14),
W-P-C8 ) 110.08(13), C6-P-C7 ) 110.1(2), C6-P-C8
) 106.8(2), C7-P-C8 ) 99.6(2), P-C8-C9 ) 130.4(3),
P-C8-C15 ) 119.7(3), C15-C8-C9 ) 109.1(3), C8-C9-
C10 ) 117.4(4), C8-C9-C13 ) 104.6(3), C13-C9-C10 )
103.5(4), C9-C10-C11 ) 103.5(4), C10-C11-C12 ) 103.3-
(4), C11-C12-C13 ) 103.7(4), C12-C13-C14 ) 114.1(4),
C12-C13-C9 ) 107.6(4), C9-C13-C14 ) 104.1(4), C13-
C14-C15 ) 106.8(4), C13-C14-O14 ) 125.4(4), O14-
C14-C15 ) 127.7(4), C14-C15-C8 ) 113.2(4).
observed for the dCH signal due to the anisotropic
influence of the W(CO)5 group and could also be
confirmed by X-ray structure analyses of anti-16b and
anti-17a (Figures 4 and 5). Compounds with a syn
configuration were not detected in the case of phospha-
nylcyclopentadiene complexes, nor was any indication
found for a possible coordination mode of one (or two)
carbon atoms.
Exp er im en ta l Section
All operations were carried out under an atmosphere of dry
argon. All solvents were dried and distilled prior to use. 1H
and 13C NMR spectra were routinely recorded on Bruker ARX
300 and AM 360 instruments. IR spectra were recorded on a
Biorad Digilab Division FTS-45 FT-IR spectrophotometer.
1J (H,C)-2J (H,C)-3J (H,C) decoupling experiments were per-
formed on a Varian 600 instrument. Elemental analyses were
determined on a Perkin-Elmer 240 elemental analyzer. Ana-
lytical TLC plates, Merck DC-Alufolien Kieselgel 60F240, were
viewed by UV light (254 nm) and stained by a 5% aqueous
acidic ammonium molybdate solution. Rf values refer to TLC
tests. Chromatographic purifications were performed on Merck
Kieselgel 100.
P en t a ca r b on yl[3-(cyclop en t -1-en yl)-1-et h oxyp r op -2-
yn -1-ylid en e]tu n gsten (3a ). W(CO)6 (3.52 g, 10.00 mmol) is

Cyclopentadiene Annelation to Cyclic Ketones
Organometallics, Vol. 18, No. 8, 1999 1375
placed in a 100 mL two-necked flask fitted with an efficient
stirrer bar and a 100 mL dropping funnel. After the apparatus
has been flushed with argon, 1-ethynylcyclopentene12 (0.92 g,
10.00 mmol; 2a ) and dry THF (20 mL) is placed into the
dropping funnel, and a solution of n-BuLi (10.00 mmol, 6.25
mL of a 1.6 M solution in hexane) is added dropwise at 20 °C,
while a slow stream of argon is passed through the solution
to achieve efficient mixing. After 15 min at 20 °C the solution
of (1-ethynylcyclopentenyl)lithium thus generated is added
dropwise within 15 min to the W(CO)6 with rapid stirring. A
clear orange solution is obtained, which is very air-sensitive.
W(CO)6 dissolves completely after approximately 80% of the
reagent has been added. Evaporation to dryness (20 °C, 20
Torr) gives a bright yellow, very air-sensitive solid, from which
the remaining THF is removed at 1 Torr and 20 °C. The
residue is dissolved in dry dichloromethane (20 mL), and the
solution is cooled to -78 °C. Triethyloxonium tetrafluoroborate
(2.85 g, 15.00 mmol) in dry dichloromethane (10 mL) is added
at -78 °C with rapid stirring. A dark mixture is formed
immediately, which is brought to dryness (20 °C, 20 Torr). The
residue is extracted efficiently four times with 50 mL portions
of Et2O to leave a grayish residue of LiBF4. Crystallization
from pentane at -40 °C affords compound 3a (3.96 g, 84%
brown needles, Rf ) 0.5 in pentane, mp 64 °C). 1H NMR
(C6D6): δ 6.20 (1 H, t, 2′-H), 3.97 (2 H, q, OCH2), 2.32, 1.98
and 1.52 (2 H each, m each, 3′-H2 to 5′-H), 0.95 (3 H, t,
OCH2CH3). 13C NMR (C6D6): δ 284.3 (Cq, WdC), 206.3 and
198.4 [1:4, Cq each, trans- and cis-CO, W(CO)5], 148.2 (CH,
C2′), 135.6 (Cq, broad, C3), 124.9 (Cq, C1′), 99.8 (Cq, broad, C2′),
76.2 (OCH2), 36.1, 35.0 and 23.7 (CH2 each, C3′-C5′), 14.6
(OCH2CH3). IR (hexane; cm-1 (%)): 2142.3 [ν(CtC)]; 2068.3
(25), 1983.6 (30), 1958.7 (100) [ν(CtO)]. MS (70 eV; m/e 184W
(%)): 472 (40) [M+], 414 (50) [M+ - 2 CO], 388 (50) [M+ - 3
CO], 330 (90) [M+ - 5 CO], 302 (90), 273 (100). Anal. Calcd
for C15H12NO6W (472.1): C, 38.16; H, 2.56. Found: C, 38.02;
H, 2.69.
206.2 and 198.6 [1:4, Cq each, trans- and cis-CO, W(CO)5],
145.7 (CH, C2′), 136.5 (Cq, broad, C3), 121.6 (Cq, C1′), 96.9 (Cq,
broad, C2′), 76.0 (OCH2), 28.9, 27.2, 22.3, and 21.3 (CH2 each,
C3′-C6′), 14.7 (OCH2CH3). IR (hexane; cm-1 (%)): 2144.7
[ν(CtC)]; 2067.6 (25), 1983.2 (30), 1955.2 (100) [ν(CtO)]. Anal.
Calcd for C16H14NO6W (486.1): C, 39.53; H, 2.90. Found: C,
39.84; H, 3.01.
P en t a ca r b on yl[3-(cycloh ep t -1-en yl)-1-et h oxyp r op -2-
yn -1-ylid en e]tu n gsten (3d ). W(CO)6 (3.52 g, 10.00 mmol) is
reacted as described above with 1-ethynylcycloheptene12 (1.20
g, 10.00 mmol; 2c), n-BuLi (10.00 mmol), and triethyloxonium
tetrafluoroborate (2.85 g, 15.00 mmol) to give compound 3d
(3.60 g, 72%, brown crystals, Rf ) 0.5 in pentane, mp 32 °C).
3
1H NMR (C6D6): δ 6.62 (1 H, t, J ) 7 Hz, 2′-H), 4.01 (2 H, q,
OCH2); 2.28, 1.87, 1.49, 1.38, and 1.26 (2 H each, m each, 3′-
H2 to 7′-H), 1.01 (3 H, t, OCH2CH3). 13C NMR (C6D6): δ 286.1
(Cq, WdC), 206.3 and 198.6 [1:4, Cq each, trans- and cis-CO,
W(CO)5], 151.2 (CH, C2′), 136.5 (Cq, broad, C3), 127.6 (Cq, C1′),
97.3 (Cq, broad, C2′), 75.9 (OCH2), 34.2, 32.0, 30.8, 26.9, and
26.2 (CH2 each, C3′-C7′), 14.7 (OCH2CH3). IR (hexane; cm-1
(%)): 2137.2 [ν(CtC)]; 2067.3 (25), 1983.9 (30), 1955.0 (100)
[ν(CtO)]. MS (70 eV; m/e (%)): 500 (10) [M+], 444 (20) [M+
-
2 CO], 360 (20) [M+ - 5 CO], 302 (40), 180 (100). Anal. Calcd
for C17H16NO6W (500.2): C, 40.82; H, 3.22. Found: C, 40.98;
H, 3.32.
4-(Cyclop e n t -1-e n yl)-4-(d im e t h yla m in o)-2-e t h oxy-
1,1,1,1,1-p en ta ca r bon yl-1-tu n gsta -1,3-bu ta d ien e ((3E)-5a )
a n d P en ta ca r bon yl[1-(d im eth yla zon ia )-3-eth oxy-3a ,5,6,
6a -tetr a h yd r o-4H-p en ta len -6a -yl]tu n gsta te (6a ). A solu-
tion of 0.5 mmol of dimethylamine (4a ) in 2 mL of dry diethyl
ether is added dropwise with stirring at 0 °C to pentacarbonyl-
[3-(cyclopent-1-enyl)-1-ethoxyprop-2-yn-1-ylidene]tungsten (236
mg, 0.5 mmol; 3a ) in 1 mL of dry diethyl ether in a 5 mL screw-
top vessel. After a color change from brown to yellow is
observed, indicating the point of equivalency, the solution is
cooled to -20 °C to give compound 5a (217 mg, 84%, yellow
crystals). Compound (3E)-5a (259 mg, 0.5 mmol) in 2 mL of
diethyl ether is rearranged completely to compound 6a at 20
°C and 12 h (pale yellow crystals at -15 °C, 231 mg, 89%, Rf
) 0.3 in 1:1 pentane/diethyl ether, mp 111 °C). Addition of 2
mL of pentane to the supernatant affords another crop of ca.
30 mg of compound 6a . The rearrangement of (3E)-5a to 6a is
very smooth and can be followed by NMR in CDCl3. Compound
6a is conveniently prepared also in a one-pot procedure from
compound 3a directly.
(3E)-5a . 1H NMR (CDCl3 at 263 K, freshly prepared
sample): δ 6.30 (1 H, s, 3-H), 5.55 (1 H, “s”, 2′-H), 4.30 (2 H,
m, diastereotopic OCH2), 3.09 and 3.01 (3 H each, s each,
NMe2), 2.62, 2.51, 2.33, and 2.00 (1:2:1:2 H, m, each 3 CH2),
1.30 (3 H, t, OCH2CH3). 13C NMR (CDCl3 at 263 K): δ 268.5
(Cq, WdC), 204.6 and 199.6 [Cq each, trans- and cis-CO of
W(CO)5], 157.2 (Cq, C4), 139.0 (Cq, C1′), 130.5 (CH, C2′), 119.3
(CH, C3), 75.7 (OCH2), 40.8 and 40.5 [N(CH3)2], 35.0 (CH2, C8),
33.2 (CH2, C6), 22.6 (CH2, C7), 14.1 (OCH2CH3). IR (hexane;
cm-1 (%)): 2056.3 (5), 1943.6 (10), 1923.7 (100) [ν(CtO)]. MS
(70 eV; m/e 184W (%)): 517 (10) [M+], 461 (10) [M+ - 2 CO],
433 (30) [M+ - 3 CO], 405 (10) [M+ - 4CO], 377 (20) [M+ - 5
CO], 193 (100). Anal. Calcd for C17H19NO6W (517.2): C, 39.48;
H, 3.70; N, 2.71. Found: C, 39.12; H, 3.57; N, 2.51.
P en t a ca r b on yl[3-(cyclop en t -1-en yl)-1-et h oxyp r op -2-
yn -1-ylid en e]ch r om iu m (3b). Cr(CO)6 (2.20 g, 10.00 mmol)
is reacted as described above with 1-ethynylcyclopentene12
(0.92 g, 10.00 mmol; 2a ), n-BuLi (10.00 mmol), and triethyl-
oxonium tetrafluoroborate (2.85 g, 15.00 mmol) to give com-
pound 3b (3.05 g, 89% red-brown crystals, Rf ) 0.5 in pentane,
1
mp 45 °C). H NMR (C6D6): δ 6.18 (1 H, t, 2′-H), 4.06 (2 H, q,
OCH2), 2.31, 2.12 and 1.60 (2 H each, m each, 3′-H2 to 5′-H),
0.99 (3 H, t, OCH2CH3). 13C NMR (C6D6): δ 314.4 (Cq, CrdC),
226.3 and 217.2 [1:4, Cq each, trans- and cis-CO, Cr(CO)5],
148.0 (CH, C2′), 135.6 (Cq, broad, C3), 124.6 (Cq, C1′), 94.1 (Cq,
broad, C2′), 76.1 (OCH2), 36.1, 35.0, and 23.7 (CH2 each, C3′-
C5′), 14.8 (OCH2CH3). IR (hexane; cm-1 (%)): 2139.9 [ν(Ct
C)]; 2061.0 (25), 1987.2 (30), 1962.8 (100) [ν(CtO)]. MS (70
eV; m/e (%)): 340 (20) [M+], 284 (20) [M+ - 2 CO], 256 (20)
[M+ - 3 CO], 228 (40) [M+ - 4 CO], 200 (100) [M+ - 5 CO],
156 (50), 143 (60). Anal. Calcd for C15H12CrNO6 (340.1): C,
52.95; H, 3.55. Found: C, 52.76; H, 3.41.
P en ta ca r bon yl[3-(cycloh ex-1-en yl)-1-eth oxyp r op -2-yn -
1-ylid en e]tu n gsten (3c). W(CO)6 (3.52 g, 10.00 mmol) is
reacted as described above with 1-ethynylcyclohexene12 (1.06
g, 10.00 mmol; 2b), n-BuLi (10.00 mmol), and triethyloxonium
tetrafluoroborate (2.85 g, 15.00 mmol) to give compound 3c
(3.79 g, 78%, brown crystals, Rf ) 0.5 in pentane, mp 67 °C).
1H NMR (C6D6): δ 6.28 (1 H, m, 2′-H), 4.01 (2 H, q, OCH2),
2.03, 1.70, 1.31, and 1.16 (2 H each, m each, 3′-H2 to 6′-H),
0.98 (3 H, t, OCH2CH3). 13C NMR (C6D6): δ 283.3 (Cq, WdC),
X-ray crystal structure analysis of compound (3E)-5a : for-
mula C17H19NO6W, Mr ) 517.18, 0.30 × 0.25 × 0.10 mm, a )
9.412(1) Å, b ) 10.337(1) Å, c ) 11.643(4) Å, R ) 112.01(1)°, â
) 105.69(1)°, γ ) 102.42°, V ) 945.41(16) Å3, Fcalcd ) 1.817 g
cm-3, µ ) 61.40 cm-1, empirical absorption correction via ψ
scan data (0.85.7 e C e 0.999), Z ) 2, triclinic, space group
P1h (No. 2), λ ) 0.710 73 Å, T ) 223 K, ω/2θ scans, 4041
reflections collected ((h, -k, (l), (sin θ)/λ ) 0.62 Å-1, 3820
independent and 3368 observed reflections [I g 2σ(I)], 229
refined parameters, R1 ) 0.039, wR2 ) 0.104, GOF 1.109,
(12) Preparation follows the procedure given in ref 5, but dehydra-
tion of the carbinol with phosphoryl chloride/pyridine was carried out
at 25 °C, since this reaction was exothermic. Furthermore, the reaction
mixture was not hydrolyzed but distilled to give a mixture of 1-eth-
ynylcycloalkene and pyridine as the only volatile products, from which
pyridine was extracted by stirring with a small excess of phosphoric
acid (ca. 80%) at 20 °C, leaving the 1-ethynylcycloalkene behind in
good yields.

1376 Organometallics, Vol. 18, No. 8, 1999
Aumann et al.
maximum (minimum) residual electron density 1.82 (-4.42)
4-(Cyclop en t-1-en yl)-2-eth oxy-4-[(S)-(m eth oxym eth yl)-
p yr r olid in e]-1,1,1,1,1-p en ta ca r bon yl-1-tu n gsta -1,3-bu ta -
d ien e ((3E)-5c) a n d P en ta ca r bon yl{3-eth oxy-1-[(2S)-2-
(m et h oxym et h yl)p yr r olid in iu m ]-3a ,5,6,6a -t et r a h yd r o-
4H-p en ta len -6a -yl}tu n gsta te ((2′′S,3a R,6a S)-6c). (S)-(-)2-
(Methoxymethyl)pyrrolidine (58 mg, 0.5 mmol; 4b) is reacted
with pentacarbonyl[3-(cyclopent-1-enyl)-1-ethoxyprop-2-yn-1-
ylidene]tungsten (236 mg, 0.5 mmol; 3a ) as described above,
except that the reaction is performed in 1:1 diethyl ether/
pentane, to give compound (3E)-5c (261 mg, 89%, Rf ) 0.6 in
3:1 pentane/diethyl ether, yellow crystals, mp 85 °C). Com-
pound (3E)-5c (294 mg, 0.5 mmol) in 2 mL of diethyl ether is
completely rearranged to compound (2′′S,3aR,6aS)-6c at 20
°C and 5 h (yellow crystals obtained at -15 °C, 270 mg, 92%,
Rf ) 0.6 in 3:1 pentane/diethyl ether, mp 85 °C).
e Å-3, hydrogens calculated and riding.13
3
6a .1H NMR (C6D6): δ 4.75 (1 H, s, 2-H), 3.82 (1 H, dd, J )
3
8 Hz, J ) 8, 3a-H), 3.47 (2 H, m, diastereotopic OCH2), 2.77
and 2.45 (3 H each, s each, NMe2), 2.25 and 1.70 (1 H each, m
each, diastereotopic 6-H2), 1.90 and 1.51 (1 H each, m each,
diastereotopic 5-H2), 1.81 and 0.85 (1 H each, m each, diaste-
reotopic 4-H2), 1.00 (3 H, t, OCH2CH3). 13C NMR (C6D6): δ
202.9 [Cq, 5 C, W(CO)5], 193.5 (Cq, CdN), 185.2 (Cq, dC-O),
93.0 (CH, C2), 67.5 (OCH2), 67.0 (CH, C3a), 50.1 (Cq, C6a),
43.0 and 41.0 [N(CH3)2], 38.6 (CH2, C6), 32.8 (CH2, C4), 31.9
(CH2, C5), 14.0 (OCH2CH3). IR (diffuse reflection; cm-1 (%)):
2050.5 (5), 1943.6 (10), 1892.4 (100) [ν(CtO)]; 1584.0 (20)
[ν(CdN+)]. MS (70 eV; m/e 184W (%)): 517 (10) [M+], 461 (10)
[M+ - 2 CO], 433 (30) [M+ - 3 CO], 405 (10) [M+ - 4CO], 377
(20) [M+ - 5 CO], 193 (100), 165 (90). Anal. Calcd for C17H19
-
(3E)-5c.1H NMR (CDCl3 at 263 K, 600 MHz, freshly
prepared sample, shifts of stereoisomer (3E)-5c′ resulting from
hindered rotation of the C4-N bond in brackets): δ 6.44 [6.27]
(1 H, s, 3-H), 5.61 [5.52] (1 H, “s”, 2′-H), 4.40 [4.38] (2 H, m,
diastereotopic 2-OCH2), 4.06 [3.66] (1 H, t, NCH), 3.60-3.02
[3.60-3.02] (4 H, m, diastereotopic 2′′-CH2O), 3.27 [3.24] (3
H, OCH3), 2.6-2.4 [2.6-2.4] (4 H, 3′′-H2 and 4′′-H2), 2.44 [2.40]
and 2.12-1.84 [2.12-1.84] (2:4 H, m each 3′-H2, 4′-H2, and
5′-H2), 1.36 [1.34] (3 H, t, OCH2CH3). 13C NMR (CDCl3 at 263
K): δ 267.8 [265.8] (Cq, WdC), 204.3 [204.2] and 199.7 [199.6]
[Cq each, trans- and cis-CO of W(CO)5], 153.4 (Cq dynamically
broadened, C4), 140.3 [138.5] (Cq broad, C1′), 129.7 [128.2] (CH
broad, C2′), 120.6 [120.6] (CH broad, C3), 76.1 [76.0] (2-OCH2),
73.0 [70.0] (2′′-CH2O), 59.1 [59.0] (OCH3), 58.7 [58.7] (NCH),
49.3 [49.0] (NCH2 broad), 37.0 [35.9] and 22.2 [22.0] (CH2 each,
C3′′ and C4′′), 34.8 [33.3] (CH2, C8), 28.5 [27.2] (CH2, C6), 22.9
[22.8] (CH2, C7), 15.3 [15.2] (OCH2CH3). IR (hexane; cm-1
(%)): 2056.0 (15), 1943.6 (10), 1923.6 (100) [ν(CtO)]. MS (70
eV; m/e 184W (%)): 587 (10) [M+], 531 (10) [M+ - 2 CO], 503
(30) [M+ - 3 CO], 447 (20) [M+ - 5 CO], 263 (100) [ligand],
248 [100]. Anal. Calcd for C21H25NO7W (587.3): C, 42.95; H,
4.29; N, 2.39. Found: C, 42.89; H, 5.17; N, 2.55.
(2′′S,3a R,6a S)-6c. 1H NMR (C6D6): δ 4.95 (1 H, s, 2-H),
3.97 (1 H, m, 2′-H), 3.95 and 3.10 (1 H each, m each,
diastereotopic 5′-H2), 3.90 (1 H, m, 3a-H), 3.55 (2 H, m,
diastereotopic 3-OCH2), 3.10 and 2.95 (1 H each, dd each,
diastereotopic 2′-OCH2), 2.99 (3 H, s, OCH3), 2.20 and 2.09 (1
H each, m each, diastereotopic 6-H2), 1.90 and 1.03 (1 H each,
m each, diastereotopic 4-H2), 1.84, 1.72, and 1.50 (2:1:1 H, m
each, NCH2CH2CH2), 1.63 and 1.58 (1 H each, m each,
diastereotopic 5-H2), 1.05 (3 H, t, OCH2CH3). 13C NMR
(C6D6): δ 202.3 [Cq, 5 C, W(CO)5], 190.3 (Cq, CdN+), 184.9 (Cq,
dC-O), 95.0 (CH, C2), 73.8 (2′-CH2O), 67.6 (3-OCH2), 66.7
(CH, C3a), 62.2 (NCH), 59.0 (OCH3), 51.0 (NCH2), 50.6 (Cq,
C6a), 38.3 (CH2, C6), 32.6 (CH2, C4), 31.6 (CH2, C5), 27.4 and
24.2 (CH2 each, C3′ and C4′), 14.4 (OCH2CH3). IR (hexane;
cm-1 (%)): 2054.1 (10), 1957.2 (10), 1911.6 (100) [ν(CtO)],
1587.4 [ν(CdN+)]. MS (70 eV; m/e 184W (%)): 587 (5) [M+], 431
(5) [M+ - 2 CO], 503 (5) [M+ - 3 CO], 447 (20) [M+ - 5CO],
263 (65) [ligand], 248 (100). Anal. Calcd for C21H25NO7W
(587.3): C, 42.95; H, 4.29; N, 2.39. Found: C, 42.89; H, 4.27;
N, 2.55.
NO6W (517.2): C, 39.48; H, 3.70; N, 2.71. Found: C, 39.32;
H, 4.05; N, 2.65.
4-(Cyclop e n t -1-e n yl)-4-(d im e t h yla m in o)-2-e t h oxy-
1,1,1,1,1-p en ta ca r bon yl-1-ch r om a -1,3-bu ta d ien e ((3E)-5b)
a n d P en ta ca r bon yl[1-(d im eth yla zon ia )-3-eth oxy-3a ,5,6,
6a -t et r a h yd r o-4H -p en t a len -6a -yl]ch r om a t e (6b ). Di-
methylamine (4a ) is reacted with pentacarbonyl[3-(cyclopent-
1-enyl)-1-ethoxyprop-2-yn-1-ylidene]chromium (3b ) as de-
scribed above to give a ca. 80% yield of compound (3E)-5b.
Compound (3E)-5b (222 mg, 0.5 mmol) in 2 mL of diethyl ether
(vide supra) is rearranged at 20 °C and 14 h. Compound 6b is
isolated from this solution at -15 °C as a yellow oil, which
affords yellow crystals (196 mg, 85%, Rf ) 0.3 in pentane/
diethyl ether 1:1, mp 92 °C) within 1-2 h.
1
(3E)-5b. H NMR (C6D6, 278 K, freshly prepared sample):
δ 6.34 (1 H, s, 3-H), 5.20 (1 H, “s”, 2′-H), 4.54 (2 H, m,
diastereotopic OCH2), 2.20 (6 H, s, NMe2), 2.15, 1.95, 1.70, 1.62
(1:2:1:2 H, m each 3 CH2), 1.03 (3 H, t, OCH2CH3). 13C NMR
(CDCl3 at 263 K): δ 287.1 (Cq, CrdC), 225.0 and 220.3 [Cq
each, trans- and cis-CO of Cr(CO)5], 154.2 (Cq, C4), 139.8 (Cq,
C1′), 130.8 (CH, C2′), 118.2 (CH, C3), 73.7 (OCH2), 39.7
[N(CH3)2], 35.6 (CH2, C8), 33.4 (CH2, C6), 23.2 (CH2, C7), 15.4
(OCH2CH3). IR (hexane; cm-1 (%)): 2044.4 (5), 1959.1 (10),
1915.6 (100) [ν(CtO)]. Anal. Calcd for C17H19CrNO6 (385.3):
C, 52.99; H, 4.97; N, 3.63. Found: C, 52.90; H, 5.12; N, 3.68.
6b. 1H NMR (C6D6): δ 4.90 (1 H, s, 2-H), 3.60 (3 H, m, 3a-H
and OCH2), 2.85 and 2.60 (3 H each, s each, NMe2), 2.50 and
1.80 (1 H each, m each, diastereotopic 6-H2), 2.15 and 1.62 (1
H each, m each, diastereotopic 5-H2), 1.81 and 0.90 (1 H each,
m each, diastereotopic 4-H2), 1.10 (3 H, t, OCH2CH3). 13C NMR
(C6D6): δ 224.6 and 219.5 [Cq each, trans- and cis-CO,
Cr(CO)5], 191.7 (Cq, CdN), 183.6 (Cq, dC-O), 93.5 (CH, C2),
67.6 (OCH2), 65.0 (CH, C3a), 51.8 (Cq, C6a), 42.2 and 41.3
[N(CH3)2], 36.7 (CH2, C6), 32.3 (CH2, C4), 31.8 (CH2, C5), 14.0
(OCH2CH3). IR (hexane; cm-1 (%)): 2044.4 (5), 1959.6 (10),
1915.6 (100) [ν(CtO)], 1591.4 (20) [ν(CdN+)]. MS (70 eV; m/e
(%)): 385 (10) [M+], 301 (10) [M+ - 3 CO], 273 (10) [M+ - 4
CO], 245 (20) [M+ - 5 CO], 193 (10) [ligand], 165 (40) [ligand
- C2H4], 124 (100). Anal. Calcd for C17H19CrNO6 (385.3): C,
52.99; H, 4.97; N, 3.63. Found: C, 52.95; H, 5.12; N, 3.68.
X-ray crystal structure analysis of compound (2′′S,3aR,6aS)-
6c: formula C21H25NO7W, Mr ) 587.27, 0.5 × 0.4 × 0.1 mm,
a ) 10.613(3) Å, b ) 18.328(4) Å, c ) 12.273(4) Å, â ) 105.49-
(2)°, V ) 2300.6(11) Å3, Fcalcd ) 1.696 g cm-3, µ ) 50.60 cm-1
,
empirical absorption correction via ψ scan data (0.644 e C e
0.999), Z ) 4, monoclinic, space group P21 (No. 4), λ ) 0.710 73
Å, T ) 223 K, ω/2θ scans, 4995 reflections collected ((h, +k,
+l), (sin θ)/λ ) 0.62 Å-1, 4774 independent and 4113 observed
reflections [I g 2σ(I)], 528 refined parameters, R1 ) 0.066,
wR2 ) 0.172, GOF 1.029, maximum (minimum) residual
electron density 4.45 (-2.07) e Å-3, Flack parameter 0.00(3),
group C17-O18-C19 in molecule I disordered, refined with
isotropic thermal parameters and with restraints, hydrogens
calculated and riding.13
(13) All data sets were collected with an Enraf-Nonius CAD4/
MACH3 diffractometer, equipped with sealed-tube or rotating-anode
generators. Programs used: data reduction MolEN, structure solution
SHELXS-86, structure refinement SHELXL-93 and SHELXL-97,
graphics (with unsystematical numbering schemes) DIAMOND.

Cyclopentadiene Annelation to Cyclic Ketones
Organometallics, Vol. 18, No. 8, 1999 1377
4-(Cyclop en t-1-en yl)-2-eth oxy-4-[(S)-(m eth oxym eth yl)-
p yr r olid in e-1,1,1,1,1-p en t a ca r b on yl-1-ch r om a -1,3-bu t a -
d ien e ((3E)-5d ) a n d P en ta ca r bon yl{3-eth oxy-1-[2-(m eth -
oxym e t h yl)p yr r olid in iu m ]-3a ,5,6,6a -t e t r a h yd r o-4H -
p en t a len -6a -yl}ch r om a t e ((2′′S,5S)-6d ). (S)-(-)-2-(Meth-
oxymethyl)pyrrolidine (58 mg, 0.5 mmol; 4b) is reacted with
pentacarbonyl[3-(cyclopent-1-enyl)-1-ethoxyprop-2-yn-1-ylidene]-
chromium (170 mg, 0.5 mmol; 3b) as described above to give
compound (3E)-5d (184 mg, 81%, Rf ) 0.6 in 2:1 pentane/
diethyl ether, yellow crystals, mp 82 °C). Compound (3E)-5d
(227 mg, 0.5 mmol) in 2 mL of diethyl ether is completely
rearranged at 20 °C and 4 h to compound (2′′S,5S)-6d (yellow
crystals obtained at -15 °C, 195 mg, 86%, Rf ) 0.6 in 2:1
pentane/diethyl ether, mp 82 °C).
(3E)-5d . 1H NMR (CDCl3 at 263 K, 600 MHz, freshly
prepared sample, stereoisomer (3E)-5d in brackets): δ 6.37
[6.21] (1 H, s, 3-H), 5.59 [5.50] (1 H, “s”, 2′-H), 4.60 [4.55] (2
H, m, diastereotopic 2-OCH2), 4.16 [3.80] (1 H, t, NCH), 3.60-
3.02 [3.60-3.02] (4 H, m, diastereotopic 2′′-CH2O), 3.35 [3.29]
(3 H, OCH3), 2.6-2.4 [2.6-2.4] (4 H, 3′′-H2 and 4′′-H2), 2.44
[2.44] and 2.12-1.84 [2.12-1.84] (2:4 H, m each 3′-H2, 4′-H2,
and 5′-H2), 1.36 [1.30] (3 H, t, OCH2CH3). 13C NMR (CDCl3 at
263 K): δ 279.8 [274.6] (Cq, CrdC), 224.4 [224.2] and 219.0
[219.0] [Cq each, trans- and cis-CO of Cr(CO)5], 152.3 [152.3]
(Cq dynamically broadened, C4), 142.3 [138.7] (Cq broad, C1′),
129.7 [128.2] (CH broad, C2′), 118.4 [118.4] (CH broad, C3),
73.4 [73.1] (2-OCH2), 73.0 [70.1] (2′′-CH2O), 59.0 [58.6] (OCH3),
58.5 (NCH), 49.9 [48.9] (NCH2 broad), 38.0 [36.0] and 22.6
[22.0] (CH2 each, C3′′ and C4′′), 35.0 [33.2] (CH2, C8), 28.3
[27.2] (CH2, C6), 22.9 [22.6] (CH2, C7), 15.4 [15.3] (OCH2CH3).
IR (hexane; cm-1 (%)): 2056.0 (15), 1943.6 (10), 1923.6 (100)
70.6 (OCH2), 49.4 and 42.5 (CH each, C3a and C6a), 45.3 and
43.1 [N(CH3)2], 28.9 and 28.4 (CH2 each, C6 and C4), 24.6 (CH2,
C5), 13.9 (OCH2CH3). IR (diffuse reflection; cm-1): 1652.0 and
1584.3 [ν(CdCCdN+)]. MS (70 eV; m/e 184W (%)): 517 (10)
[M+], 461 (10) [M+ - 2 CO], 433 (30) [M+ - 3 CO], 405 (10)
[M+ - 4CO], 377 (20) [M+ - 5 CO], 193 (100) [ligand], 165
(90) [193 - C2H4]. Anal. Calcd for C17H20BF4NO (341.2): C,
59.85; H, 5.91; N, 4.12. Found: C, 59.12; H, 6.10; N, 3.90.
1
9a . H NMR (CDCl3): δ 4.86 (1 H, s, 2-H), 3.18 and 2.80 (1
H each, m each, 3a-H and 6a-H), 3.05 and 2.85 (3 H each, s
each, NMe2), 1.94 and 1.60 (1 H each, m each, diastereotopic
6-H2), 1.76 and 1.57 (1 H each, m each, diastereotopic 5-H2),
1.54 and 1.40 (1 H each, m each, diastereotopic 4-H2). 13C NMR
(CDCl3): δ 205.5 (Cq, CdO), 179.6 (Cq, dCN), 100.2 (CH, C2),
51.4 and 44.1 (CH each, C3a and C6a), 39.5 and 38.5 [N(CH3)2],
30.3 and 29.3 (CH2 each, C4 and C6), 24.2 (CH2, C5). IR
(diffuse reflection; cm-1): 1576 [ν(CdO)]. MS (70 eV; m/e (%)):
165 (40) [M+], 137 (20), 124 (100). Anal. Calcd for C10H15NO
(165.2): C, 72.69; H, 9.15; N, 8.48. Found: C, 72.24; H, 9.80;
N, 8.82.
4-(Cyclop en t-1-en yl)-2-eth oxy-1,1,1,1,1-p en ta ca r bon yl-
4-(p h en yla m in o)-1-tu n gsta -1,3-bu ta d ien e ((3Z)-10a ), P en -
ta ca r bon yl[(3-eth oxy-3a ,5,6,6a -tetr a h yd r o-4H-p en ta len -
6a -ylid en e)p h en yla m in e-N]tu n gsten (syn -11a a n d a n ti-
11a ), a n d (3-Eth oxy-3a ,5,6,6a -tetr a h yd r o-4H-p en ta len -6a -
ylid en e)p h en yla m in e (12). A solution of aniline (47 mg, 0.5
mmol) in 1 mL of dry diethyl ether is a added dropwise and
slowly at 0 °C with stirring to pentacarbonyl[3-(cyclopent-1-
enyl)-1-ethoxyprop-2-yn-1-ylidene]tungsten (236 mg, 0.50 mmol;
3a ) in 1 mL of dry diethyl ether. A color change from brown
to red is observed at the point of equivalency after ca. 5 min.
The solvent is removed immediately by evaporation to leave
a red, thermolabile oil of compound (3Z)-10a (Rf ) 0.7 in 10:1
pentane/diethyl ether). Compound (3Z)-10a generated by
reaction of aniline (47 mg, 0.5 mmol) with 3a (236 mg, 0.5
mmol) is rearranged at 50 °C and 4 h in 1 mL of toluene to
give a 2:1 mixture of compounds syn-11a and anti-11a (255
mg, 89%, orange oil), which is separated by chromatography
on silica gel to give anti-11a (Rf ) 0.8 10:1 pentane/diethyl
ether, yellow crystals, mp 136 °C) and syn-11a (Rf ) 0.7 10:1
pentane/diethyl ether, orange crystals, mp 108 °C) and a small
fraction of the colorless, very polar compound 12. Compound
syn-11a rearranges to anti-11a in C6D6 at 50 °C. Compound
12 is generated under the influence of air in solutions both of
syn-11a and anti-11a .
(3Z)-10a . 1H NMR (C6D6 at 283 K, freshly prepared
sample): δ 10.12 (1 H, s broad, NH), 7.01, 6.92, and 6.75 (2:
1:2 H; “t”, “t”, “d”; C6H5), 6.88 (1 H, s, 3-H), 6.08 (1 H, “s” broad,
2′-H), 4.45 (2 H, q, OCH2), 1.96 and 1.46 (4:2 H, CH2 each),
0.96 (3 H, t, OCH2CH3). 13C NMR (C6D6 at 283 K): δ 275.0
(Cq, WdC), 204.7 and 199.6 [Cq each, trans- and cis-CO of
W(CO)5], 149.7 (Cq, i-C NPh), 139.0 and 138.8 (Cq each, C4
and C1′), 139.7 (CH, C2′), 129.7, 129.6, 126.3, 124.8, and 123.5
(CH each, 1:1:1:1:1; 2 m-C, p-C, and 2 o-C; Ph), 122.5 (CH,
C2′), 94.0 (CH, C3), 77.0 (OCH2), 33.8 and 33.4 (CH2 each, C8
and C6), 24.0 (CH2, C7), 14.9 (OCH2CH3). IR (hexane; cm-1
(%)): 2058.8 (5), 1968.8 (10), 1931.0 (100) [ν(CtO)]. Anal.
Calcd for C21H19NO6W (565.2): C, 44.62; H, 3.39; N, 2.48.
Found: C, 45.01; H, 3.57; N, 2.57.
a n ti-11a . 1H NMR (C6D6): δ 7.16 and 7.12 (1 H each, m
each, m-H Ph), 6.90 (CH, m, p-H Ph), 6.87 and 6.72 (1 H each,
o-H Ph), 4.48 (1 H, s, 2-H), 3.28 (1 H, m, 6a-H), 2.85 and 2.75
(1 H each, m each, diastereotopic OCH2), 2.70 (1 H, m, 3a-
H), 2.15 and 1.65 (1 H each, m each, diastereotopic 4-H2), 2.00
and 1.41 (1 H each, m each, diastereotopic 5-H2), 1.20 (2 H, m
each, diastereotopic 6-H2), 0.70 (3 H, t, OCH2CH3). 13C NMR
(C6D6): δ 204.4 and 199.7 [Cq each, trans- and cis-CO, W(CO)5],
190.7 (Cq, CdN), 184.0 (Cq, dC-O), 158.5 (Cq, i-C NPh), 129.7
and 129.5 (CH each, m-C NPh), 125.7 and 121.4 (CH each,
o-C NPh), 121.9 (CH, p-C NPh), 99.9 (CH, C2), 67.2 (OCH2),
50.0 and 48.6 (CH each, C6a and C3a), 32.6 (CH2, C4), 28.5
[ν(CtO)]. MS (70 eV; m/e (%)): 455 (10) [M+], 399 (10) [M+
-
2 CO], 343 (30) [M+ - 4 CO], 315 (20) [M+ - 5 CO], 263 (100)
[ligand], 248 [100]. Anal. Calcd for C21H25CrNO7 (455.3): C,
55.38; H, 5.53; N, 3.08. Found: C, 55.04; H, 5.65; N, 3.16.
1
(2′′S,5S)-6d . H NMR (C6D6): δ 4.95 (1 H, s, 2-H), 3.82 (1
H, m, 2′-H), 3.78 and 3.00 (1 H each, m each, diastereotopic
5′-H2), 3.70 (1 H, m, 3a-H), 3.65 (2 H, m, diastereotopic
3-OCH2), 2.92 and 2.81 (1 H each, diastereotopic 2′-CH2O), 2.85
(3 H, s, OCH3), 2.10-1.60 (10 H, m, 5 CH2), 0.90 (3 H, t,
OCH2CH3). 13C NMR (C6D6): δ 224.6 and 219.8 [Cq each, trans-
and cis-CO, W(CO)5], 187.8 (Cq, CdN+), 182.8 (Cq, dC-O), 95.0
(CH, C2), 73.7 (2′-CH2O), 64.6 (CH, C3a), 62.2 (NCH), 59.0
(OCH3), 54.3 (Cq, C6a), 51.6 (NCH2), 36.0 (CH2, C6), 32.0 (CH2,
C5), 31.0 (CH2, C5), 27.1 and 24.0 (CH2 each, C3′ and C′4),
14.1 (OCH2CH3). IR (hexane; cm-1 (%)): 2047.2 (10), 1986.2
(10), 1926.4 (100) [ν(CtO)]; 1558.4 [ν(CdN+)]. MS (70 eV; m/e
184W (%)): 587 (5) [M+], 431 (5) [M+ - 2 CO], 503 (5) [M+ - 3
CO], 447 (20) [M+ - 5CO], 263 (65) [ligand], 248 (100). Anal.
Calcd for C21H25CrNO7 (455.3): C, 55.38; H, 5.53; N, 3.08.
Found: C, 55.21; H, 5.27; N, 2.95.
1-(Dim eth yla zon ia )-3-eth oxy-3a ,5,6,6a -tetr a h yd r o-4H-
pen talen e Tetr aflu or obor ate (7a) an d 3-(Dim eth ylam in o)-
3a,5,6,6a-tetr ah ydr o-4H-pen talen -1-on e (9a). Pentacarbonyl-
[1-(dimethylazonia)-3-ethoxy-3a,5,6,6a-tetrahydro-4H-pentalen-
6a-yl]tungstate (259 mg, 0.5 mmol; 6a ) in 5 mL of diethyl
ether, water (9 mg, 0.5 mmol), and Et3OBF4 (95 mg, 0.5 mmol)
was stirred until the mixture turned colorless (at 20 °C, 14
h). The crystalline residue of compound 7a was washed with
diethyl ether in order to remove W(CO)6 and dried in vacuo
(125 mg, 89%). Reaction of 7a with 10% KOH in water affords
the colorless ketone 9a . A 1:1 mixture of compound 6a and
pyridine in C6D6 was heated for 5 h at 70 °C to give a 1:1
mixture of compounds 6a and 9a .
7a . 1H NMR (CDCl3): δ 5.91 (1 H, s, 2-H), 4.32 (2 H, m,
diastereotopic OCH2), 3.59 and 3.41 (1 H each, m each, 3a-H
and 6a-H), 3.40 and 3.39 (3 H each, s each, NMe2), 2.21 and
1.76 (1 H each, m each, diastereotopic 6-H2), 1.86 and 1.72 (1
H each, m each, diastereotopic 5-H2), 1.74 and 1.49 (1 H each,
m each, diastereotopic 4-H2), 1.42 (3 H, t, OCH2CH3). 13C NMR
(CDCl3): δ 193.7 (Cq, dCOEt), 187.6 (Cq, CdN), 98.9 (CH, C2),

1378 Organometallics, Vol. 18, No. 8, 1999
Aumann et al.
(CH2, C6), 24.0 (CH2, C5), 13.7 (OCH2CH3). IR (hexane; cm-1
(%)): 2067.4 (5), 1970.5 (10), 1927.9 (100), 1907.6 (30) [ν(Ct
O)]; 1576.4 (20) [ν(CdN)]. MS (70 eV; m/e 184W (%)): 565 (10)
[M+], 537 (10), 509 (80) [M+ - 2 CO], 481 (10) [M+ - 3 CO],
453 (40) [M+ - 4CO], 425 (60) [M+ - 5 CO], 241 (100) [ligand].
Anal. Calcd for C21H19NO6W (565.2): C, 44.62; H, 3.39; N, 2.48.
Found: C, 44.79; H, 3.82; N, 2.70.
1:2 H, C6H5), 6.68 (1 H, s, 3-H), 6.08 (1 H, “s” broad, 2′-H),
4.62 (2 H, q, OCH2), 1.96 and 1.42 (4:2 H, CH2 each), 0.90 (3
H, t, OCH2CH3). 13C NMR (C6D6 at 303 K): δ 298.8 (Cq, Crd
C), 224.4 and 219.2 [Cq each, trans- and cis-CO of Cr(CO)5],
145.7 (Cq, i-C NPh), 140.0 and 138.8 (Cq each, C4 and C1′),
139.5 (CH, C2′), 129.7, 129.4, 126.9, 125.0, and 122.5 (CH each,
1:1:1:1:1; 2 m-C, p-C and 2 o-C; NPh), 122.5 (CH, C2′), 94.2
(CH, broad, C3), 74.4 (OCH2), 33.8 and 33.3 (CH2 each, C8
and C6), 24.0 (CH2, C7), 15.0 (OCH2CH3).
a n ti-11b. 1H NMR (C6D6): δ 7.15 and 7.10 (1 H each, m
each, m-H Ph), 6.90 (CH, m, p-H Ph), 6.85 and 6.73 (1 H each,
o-H Ph), 4.47 (1 H, s, 2-H), 3.30 (1 H, m, 6a-H), 2.83 and 2.70
(1 H each, m each, diastereotopic OCH2), 2.74 (1 H, m, 3a-H),
2.10 and 1.62 (1 H each, m each, diastereotopic 4-H2), 2.03
and 1.41 (1 H each, m each, diastereotopic 5-H2), 1.23 (2 H, m
each, diastereotopic 6-H2), 0.68 (3 H, t, OCH2CH3). 13C NMR
(C6D6): δ 222.6 and 215.5 [Cq each, trans- and cis-CO, W(CO)5],
190.6 (Cq, CdN), 182.6 (Cq, dC-O), 159.0 (Cq, i-C NPh), 129.9
and 129.6 (CH each, m-C NPh), 125.1 and 121.5 (CH each,
o-C NPh), 125.0 (CH, p-C NPh), 100.1 (CH, C2), 67.0 (OCH2),
48.9 and 48.4 (CH each, C6a and C3a), 33.0 (CH2, C4), 28.5
(CH2, C6), 24.0 (CH2, C5), 13.7 (OCH2CH3). IR (hexane; cm-1
(%)): 2063.0 (5), 1975.1 (10), 1933.1 (100), 1908.9 (30) [ν(Ct
O)]; 1574.1 (20) [ν(CdN)]. MS (70 eV; m/e (%)): 433 (5) [M+],
377 (5) [M+ - 2 CO], 321 (5) [M+ - 4CO], 293 (80) [M+ - 5
CO], 241 (100) [ligand], 99 (80). Anal. Calcd for C21H19CrNO6
(433.4): C, 58.20; H, 4.42; N, 3.23. Found: C, 58.64; H, 4.90;
N, 3.52.
syn -11b. 1H NMR (C6D6): δ 7.09 (2 H, m, m-H Ph), 6.86
(CH, m, p-H Ph), 6.79 and 6.51 (1 H each, o-H Ph), 5.89 (1 H,
s, 2-H), 3.69 (2 H, m, diastereotopic OCH2), 2.63 and 2.50 (1
H each, m each, 3a-H and 6a-H), 1.4-0.8 (6 H, m, 3 CH2), 1.00
(3 H, t, OCH2CH3). 13C NMR (C6D6): δ 222.1 and 215.5 [Cq
each, trans- and cis-CO, W(CO)5], 189.6 (Cq, CdN), 184.2 (Cq,
dC-O), 155.7 (Cq, i-C NPh), 129.2 and 128.8 (CH each, m-C
NPh), 125.1 (CH, p-C NPh), 123.8 and 121.6 (CH each, o-C
NPh), 103.2 (CH, C2), 67.8 (OCH2), 48.9 and 46.7 (CH each,
C6a and C3a), 31.5 (CH2, C4), 28.8 (CH2, C6), 26.0 (CH2, C5),
13.9 (OCH2CH3). IR (hexane; cm-1 (%)): 2063.4 (5), 1975.1 (10),
1932.9 (100), 1908.3 (30) [ν(CtO)]; 1579.0 (20) [ν(CdN)]. MS
(70 eV; m/e (%)): 433 (10) [M+], 377 (5) [M+ - 2 CO], 321 (5
[M+ - 4CO], 293 (60) [M+ - 5 CO], 241 (80) [ligand], 99 (100).
Anal. Calcd for C21H19CrNO6 (433.4): C, 58.20; H, 4.42; N, 3.23.
Found: C, 58.30; H, 5.07; N, 3.41.
syn -11a . 1H NMR (C6D6): δ 7.07 (2 H, m, m-H Ph), 6.84
(CH, m, p-H Ph), 6.82 and 6.52 (1 H each, o-H Ph), 5.92 (1 H,
s, 2-H), 3.62 (2 H, m, diastereotopic OCH2), 2.62 and 2.51 (1
H each, m each, 6a-H and 3a-H), 1.4-0.8 (6 H, m, 3 CH2), 0.92
(3 H, t, OCH2CH3). 13C NMR (C6D6): δ 203.3 and 199.9 [Cq
each, trans- and cis-CO, W(CO)5], 189.8 (Cq, CdN), 184.6 (Cq,
dC-O), 155.3 (Cq, i-C NPh), 129.8 and 129.4 (CH each, m-C
NPh), 125.6 (CH, p-C NPh), 123.9 and 121.3 (CH each, o-C
NPh), 105.7 (CH, C2), 68.0 (OCH2), 50.0 and 45.7 (CH each,
C6a and C3a), 32.6 (CH2, C4), 28.7 (CH2, C6), 26.0 (CH2, C5),
13.8 (OCH2CH3). IR (hexane; cm-1 (%)): 2067.4 (5), 1970.1 (10),
1928.9 (100), 1907.1 (30) [ν(CtO)]; 1575.4 (20) [ν(CdN)]. MS
(70 eV; m/e 184W (%)): 565 (20) [M+], 537 (10), 509 (95) [M+
-
2 CO], 481 (10) [M+ - 3 CO], 453 (40) [M+ - 4CO], 425 (60)
[M+ - 5 CO], 241 (100) [ligand]. Anal. Calcd for C21H19NO6W
(565.2): C, 44.62; H, 3.39; N, 2.48. Found: C, 44.63; H, 3.64;
N, 2.64.
X-ray crystal structure analysis of compound anti-11a :
formula C21H19NO6W, Mr ) 565.22, 0.3 × 0.2 × 0.2 mm, a )
9.801(4) Å, b ) 10.423(3) Å, c ) 11.903(3) Å, R ) 97.39(2)°, â
) 112.70(2)°, γ ) 104.98(2)°, V ) 1047.5(6) Å3, Fcalcd ) 1.792 g
cm-3, µ ) 55.50 cm-1, empirical absorption correction via ψ
scan data (0.799 e C e 0.999), Z ) 2, triclinic, space group P1h
(No. 2), λ ) 0.710 73 Å, T ) 223 K, ω/2θ scans, 4424 reflections
collected ((h, (k, +l), (sin θ)/λ ) 0.62 Å-1, 4215 independent
and 3881 observed reflections [I g 2σ(I)], 263 refined param-
eters, R1 ) 0.021, wR2 ) 0.056, GOF 1.167, maximum
(minimum) residual electron density 0.84 (-1.17) e Å-3
,
hydrogens calculated and riding.13
1
12. H NMR (C6D6): δ 7.29 (2 H, m, m-H Ph), 7.12 (2 H, m,
o-H Ph), 6.99 (CH, m, p-H Ph), 5.18 (1 H, s, 3-H), 3.18 (1 H,
m, 5-H), 3.05 and 2.85 (1 H each, m each, diastereotopic OCH2),
2.30 (1 H, m, 1-H), 1.7-1.2 (6 H, m, 3 CH2), 0.82 (3 H, t,
OCH2CH3). 13C NMR (C6D6): δ 181.5 (Cq, CdN), 177.6 (Cq, d
C-O), 154.5 (Cq, i-C NPh), 129.2 (CH, m-C NPh), 122.1 (CH,
p-C NPh), 121.3 (CH, o-C NPh), 97.4 (CH, C3), 66.3 (OCH2),
48.7 and 46.6 (CH each, C5 and C1), 32.3 (CH2, C8), 29.4 (CH2,
C6), 24.2 (CH2, C7), 14.0 (OCH2CH3). IR (diffuse reflection;
cm-1 (%)): 1645.4 [ν(CdN)]. MS (70 eV; m/e (%)): 241 (100)
[M+], 213 (40), 185 (30), 144 (30). Anal. Calcd for C21H19NO6W
(565.2): C, 44.62; H, 3.39; N, 2.48. Found: C, 44.79; H, 3.82;
N, 2.70.
P en ta ca r bon yl[4-eth oxy-6-(d i-ter t-bu tylp h osp h a n yl)-
1,2,3,3a -tetr a h yd r op en ta len e-P ]tu n gsten (a n ti-14a ), P en -
ta ca r bon yl[4-eth oxy-6-(di-ter t-bu tylph osp h a n yl)-1,2,3,6a -
tetrahydropentalene-P]tungsten (anti-15a),andPentacarbonyl[3-
(d i-t er t -b u t y lp h o s p h a n y l)-3a ,5,6,6a -t e t r a h y d r o -4H -
p en ta len -1-on e-P ]tu n gsten (a n ti-17a ). To pentacarbonyl-
[3-(cyclopent-1-enyl)-1-ethoxyprop-2-yn-1-ylidene]tungsten (236
mg, 0.5 mmol; 3a ) in 1 mL of pentane is added di-tert-
butylphosphine (73 mg, 0.5 mmol; 13a ) in 2 mL of pentane
dropwise at 0 °C with stirring in a 5 mL screw-top vessel. After
the color change to yellow is observed, indicating that the point
of equivalency is achieved, the solution separated by fast (!)
chromatography on silica gel to give compound anti-14a (Rf )
0.6 in 50:1 pentane/diethyl ether, yellow crystals, mp 90 °C),
compound anti-15a (Rf ) 0.5 in 50:1 pentane/diethyl ether,
yellow crystals, mp 76 °C), and compound anti-17a (Rf ) 0.5
in diethyl ether, yellow crystals, mp 127 °C). The overall yield
of compounds anti-14a + anti-15a + anti-17a corresponds to
ca. 80%. Since anti-14a readily undergoes thermal rearrange-
ment to anti-15a and also is hydrolyzed on silica gel to give
anti-17a , the relative yields depend very much on the details
of the preparation.
4-(Cyclop en t-1-en yl)-2-eth oxy-1,1,1,1,1-p en ta ca r bon yl-
4-(p h en yla m in o)-1-ch r om a -1,3-bu ta d ien e ((3Z)-10b) a n d
P en t a ca r b on yl[(3-et h oxy-3a ,5,6,6a -t et r a h yd r o-4H -p en -
talen -6a-yliden e)ph en ylam in e-N]ch r om iu m (syn -11b an d
a n ti-11b). A solution of aniline (47 mg, 0.5 mmol) is reacted
with pentacarbonyl[3-(cyclopent-1-enyl)-1-ethoxyprop-2-yn-1-
ylidene]chromium (170 mg, 0.5 mmol; 3b) as described above
to give compound (3Z)-10a (Rf ) 0.7 in 10:1 pentane/diethyl
ether; red, thermolabile oil). Compound (3Z)-10b generated
by reaction of aniline (47 mg, 0.5 mmol) with 3b (170 mg, 0.5
mmol) as described above is rearranged at 50 °C and 4 h in 1
mL of toluene to give a 1:1 mixture of compounds syn-11b and
anti-11b (255 mg, 89%, orange oil), which are separated by
chromatography on silica gel to give anti-11b (Rf ) 0.8 10:1
pentane/diethyl ether, yellow crystals, mp 99 °C) and syn-11b
(Rf ) 0.7 10:1 pentane/diethyl ether) and a fraction of the
colorless, very polar compound 12 (vide supra). Compound syn-
11b rearranges to anti-11b in C6D6 at 50 °C. Compound 12 is
generated under the influence of air from solutions both of syn-
11b and anti-11b.
1
3
a n ti-14a . H NMR (C6D6): δ 5.68 [1 H, d, J (P,H) ) 8 Hz,
5-H], 3.65 (2 H, m, diastereotopic OCH2), 3.36 (1 H, m, 3a-H),
2.38 (2 H, m, diastereotopic 1-H2), 1.90 and 1.60 (2 H each, m
each, 2-H2 and 3-H2), 1.31 and 1.25 [3 H each, d each, 3J (P,H)
) 13 Hz each, diastereotopic Pt-Bu2], 1.10 (3 H, t, OCH2CH3).
(3Z)-10b. 1H NMR (C6D6 at 303 K, freshly prepared
sample): δ 10.00 (1 H, s broad, NH), 6.90, 6.82, and 6.71 (2:

Cyclopentadiene Annelation to Cyclic Ketones
Organometallics, Vol. 18, No. 8, 1999 1379
13C NMR (C6D6): δ 200.2 [Cq, 4 C, 2J (P,C) ) 7 Hz, cis-CO,
(CO)5W], 199.2 [Cq, 2J (P,C) ) 24 Hz, trans-CO, (CO)5W], 164.5
[Cq, 3J (P,C) ) 9 Hz, C4], 153.5 [Cq, 2J (P,C) ) 0 Hz, C6a], 149.9
[Cq, 1J (P,C) ) 17 Hz, C6], 109.2 [CH, 2J (P,C) ) 17 Hz, C5],
65.4 (OCH2), 60.4 [CH, 3J (P,C) ) 6 Hz, C3a], 37.9 and 37.4
[Cq each, 1J (P,C) ) 13 Hz each, diastereotopic PCMe3], 30.6
(CH2, C1), 29.2 and 26.3 (CH2 each, C2 and C3), 31.3 and 31.0
[CH3 each, 2J (P,C) ) 7 Hz each, diastereotopic CMe3], 14.5
(OCH2CH3). IR (hexane; cm-1 (%)): 2066.1 (20), 1970.0 (5),
1938.5 (90), 1928.0 (100) [ν(CtO)]. MS (70 eV; 184W, m/e (%)):
618 (20) [M+], 590 (5), 562 (40), 534 (20), 506 (60), 478 (10)
[M+ - 5 CO], 417 (70), 294 (20) [ligand], 237 (60), 57 (100).
enyl)-1-ethoxyprop-2-yn-1-ylidene]tungsten (3a ) (236 mg, 0.5
mmol) is reacted with dicyclohexylphosphine (99 mg, 0.5 mmol;
13b) as described above to give compound anti-14b (202 mg,
30%, Rf ) 0.5 in 50:1 pentane/diethyl ether), compound anti-
15b (45 mg, 7%, Rf ) 0.6 in 50:1 pentane/diethyl ether),
compound anti-16b (240 mg, 36%, Rf ) 0.6 in 50:1 pentane/
diethyl ether, mp 151 °C), and compound anti-17b (140 mg,
22%, Rf ) 0.3 in 4:1 pentane/dichloromethane, mp 163 °C).
Since anti-14b readily undergoes thermal rearrangement to
anti-15b and anti-16b and is readily hydrolyzed on silica gel
to give anti-17b, the relative yields depend very much on the
details of preparation.
1
3
Anal. Calcd for
C23H31O6PW (618.3): C, 44.68; H, 5.05.
a n ti-14b. H NMR (C6D6): δ 5.52 [1 H, d, J (P,H) ) 2 Hz,
5-H], 3.65 (2 H, m, diastereotopic OCH2), 3.42 (1 H, m, 1-H),
2.30 (2 H, m, diastereotopic 1-H2), 2.10-1.10 (26 H, m; 2-H2,
3-H2, and 2 Cy), 1.10 (3 H, t, OCH2CH3). 13C NMR (C6D6): δ
199.3 [Cq, 4 C, 2J (P,C) ) 6 Hz, cis-CO, (CO)5W], 199.5 [Cq,
2J (P,C) ) 22 Hz, trans-CO, (CO)5W], 165.9 [Cq, 3J (P,C) ) 9
Found: C, 44.61; H, 4.97.
1
3
a n ti-15a . H NMR (C6D6): δ 7.40 [1 H, d, J (P,H) ) 8 Hz,
5-H], 3.85 (2 H, m, diastereotopic OCH2), 3.38 (1 H, m, 6a-H),
2.20 (2 H, m, diastereotopic 3-H2), 2.00 and 1.85 (2 H each, m
each, 2-H2 and 1-H2), 1.28 and 1.05 [3 H each, d each, 3J (P,H)
) 14 Hz each, diastereotopic P-t-Bu2], 1.07 (3 H, t, OCH2CH3).
13C NMR (C6D6): δ 199.8 [Cq, 4 C, 2J (P,C) ) 7 Hz, cis-CO,
(CO)5W], 198.9 [Cq, 2J (P,C) ) 22 Hz, trans-CO, (CO)5W], 150.8
[Cq, 3J (P,C) ) 15 Hz, C4], 150.0 [CH, 2J (P,C) ) 19 Hz, C5],
138.9 [Cq, 1J (P,C) ) 20 Hz, C6], 132.0 [Cq, 3J (P,C) ) 0 Hz,
C3a], 65.0 (OCH2), 61.9 (CH, C6a), 38.9 and 36.5 [Cq each,
1J (P,C) ) 13 and 15 Hz, respectively, diastereotopic PCMe3],
32.7 (CH2, C3), 31.0 and 22.5 (CH2 each, C2 and C1), 30.8 and
30.4 [CH3 each, 2J (P,C) ) 6 Hz each, diastereotopic CMe3], 15.3
(OCH2CH3). IR (hexane; cm-1 (%)): 2067.1 (20), 1970.3 (5),
1935.5 (100) [ν(CtO)]. MS (70 eV; 184W, m/e (%)): 618 (10)
[M+], 590 (5), 534 (30), 506 (20), 478 (30) [M+ - 5 CO], 154
(60), 57 (100). Anal. Calcd for C23H31O6PW (618.3): C, 44.68;
H, 5.05. Found: C, 44.31; H, 5.07.
2
1
Hz, C4), 153.6 [Cq, J (P,C) ) 0 Hz, C6a], 149.5 [Cq, J (P,C) )
15 Hz, C6], 106.2 [CH, 2J (P,C) ) 26 Hz, C5], 65.4 (OCH2), 60.4
3
1
[CH, J (P,C) ) 7 Hz, C3a], 38.5 and 36.5 [CH each, J (P,C) )
24 Hz each, diastereotopic PCH], 30.8 (CH2, C1), 29.6 and 25.8
(CH2 each, C2 and C3), 29.3-26.0 (10 CH2, diastereotopic
PCy2), 14.3 (OCH2CH3). IR (hexane; cm-1 (%)): 2066.7 (20),
1969.5 (5), 1937.4 (100), 1928.0 (70) [ν(CtO)]. MS (70 eV; 184W,
m/e (%)): 670 (20) [M+], 642 (25), 614 (40), 586 (60), 558 (40),
530 (30) [M+ - 5 CO], 55 (100). Anal. Calcd for C27H35O6PW
(670.4): C, 48.37; H, 5.26. Found: C, 48.60; H, 5.36.
a n ti-15b. 1H NMR (C6D6): δ 7.230 [1 H, d, 3J (P,H) ) 8 Hz,
5-H], 3.90 (2 H, m, diastereotopic OCH2), 3.30 (1 H, m, 6a-H),
2.25 (2 H, m, diastereotopic 1-H2), 2.20-1.10 (26 H, m; 2-H2,
3-H2 and 2 Cy), 1.07 (3 H, t, OCH2CH3). 13C NMR (C6D6): δ
199.6 [Cq, 4 C, cis-CO, (CO)5W], 198.0 [Cq, trans-CO, (CO)5W],
151.2 (Cq, C4), 150.2 (CH, C5), 137.0 (Cq, C6), 132.2 (Cq, C3a),
65.2 (OCH2), 61.9 (CH, C6a), 38.5 and 36.5 [CH each, diaste-
reotopic PCH], 32.7 (CH2, C3); 31.0 and 22.8 (CH2 each, C2
and C1), 29.4-25.9 (10 CH2, diastereotopic PCy2), 15.2
(OCH2CH3). IR (hexane; cm-1 (%)): 2067.0 (20), 1972.3 (5),
1935.2 (100) [ν(CtO)].
1
3
a n ti-17a . H NMR (C6D6): δ 6.63 [1 H, d, J (P,H) ) 6 Hz,
2-H], 3.30 (1 H, m, 6a-H), 2.60 (1 H, m, 3a-H), 1.95 and 1.70
(1 H each, m each, diastereotopic 4-H2), 1.30-1.20 (4 H, m,
3
5-H2 and 6-H2), 1.08 and 1.01 [3 H each, d each, J (P,H) ) 14
Hz each, diastereotopic P-t-Bu2]. 13C NMR (C6D6): δ 208.5 (Cq,
3J (P,C) ) 11 Hz, CdO], 199.2 [Cq, 4 C, 2J (P,C) ) 7 Hz, cis-
2
CO, (CO)5W], 198.0 [Cq, J (P,C) ) 22 Hz, trans-CO, (CO)5W],
174.2 (Cq, 1J ) 4 Hz, C3), 143.5 [CH, 2J (P,C) ) 6 Hz, C2], 54.6
a n ti-16b. 1H NMR (C6D6): δ 3.78 [2 H, m, 5-H2], 3.70 (2 H,
m, diastereotopic OCH2), 2.32 (2 H, m, diastereotopic 3-H2),
2.19 (2 H, m, 2-H2), 2.10-1.10 (24 H, m, 1-H2 and 2 Cy), 1.04
2
(CH, C6a), 53.0 (CH, J ) 4 Hz, C3a), 38.3 and 37.9 [Cq each,
1J (P,C) ) 13 and 11 Hz, respectively, diastereotopic PCMe3],
2
2
(3 H, t, OCH2CH3). 13C NMR (C6D6): δ 199.4 [Cq, 4 C, J (P,C)
34.5 (CH2, C4), 31.3 and 31.0 [CH3 each, J (P,C) ) 5 Hz each,
) 8 Hz, cis-CO, (CO)5W], 199.3 [Cq, 2J (P,C) ) 21 Hz, trans-
CO, (CO)5W], 166.5 [Cq, 3J (P,C) ) 0 Hz, C4), 158.9 [Cq, 1J (P,C)
) 9 Hz, C6], 149.5 [Cq, 2J (P,C) ) 6 Hz, C6a], 106.3 [CH, 3J (P,C)
diastereotopic CMe3], 27.2 and 27.1 (CH2 each, C5 and C6).
IR (hexane; cm-1 (%)): 2068.4 (20), 1973.2 (5), 1935.9 (100)
[ν(CtO)]; 1710.5 [ν(CdO)]. MS (70 eV; 184W, m/e (%)): 590 (10)
[M+], 562 (5), 534 (30), 506 (20), 476 (30), 450 (30) [M+ - 5
CO], 421 (30), 391 (20), 266 (10) [ligand], 210 (10), 154 (60),
57 (100). Anal. Calcd for C21H27O6PW (590.3): C, 42.73; H,
4.61. Found: C, 42.66; H, 4.63.
2
) 43 Hz, C3a], 65.9 (OCH2), 53.4 (CH2, J ) 20 Hz, C5), 37.5
[2 PCH, 1J (P,C) ) 26 Hz), 30.6 (CH2, C1), 29.0 (CH2, C2), 28.8
and 28.4 (CH2 each, diastereotopic PCHCH2), 27.3 and 27.0
3
(CH2 each, J ) 13 and 11 Hz, diastereotopic PCHCH2CH2),
26.3 (2 CH2, PCHCH2CH2CH2), 24.4 (CH2, C2), 15.2 (OCH2CH3).
IR (hexane; cm-1 (%)): 2065.1 (20), 1967.5 (5), 1932.6 (100)
[ν(CtO)]. Anal. Calcd for C27H35O6PW (670.4): C, 48.37; H,
5.26. Found: C, 48.52 H, 5.42.
X-ray crystal structure analysis of compound anti-17a :
formula C21H27O6PW, Mr ) 590.25, 0.7 × 0.5 × 0.4 mm, a )
14.810(1) Å, b ) 10.653(2) Å, c ) 15.583(1) Å, â ) 110.19(1)°,
V ) 2307.5(5) Å3, Fcalcd ) 1.699 g cm-3, µ ) 51.07 cm-1
,
empirical absorption correction via ψ scan data (0.758 e C e
0.999), Z ) 4, monoclinic, space group P21/n (No. 14), λ )
0.710 73 Å, T ) 223 K, ω/2θ scans, 4854 reflections collected
((h, -k, -l), (sin θ)/λ ) 0.62 Å-1, 4680 independent and 4173
observed reflections [I g 2σ(I)], 268 refined parameters, R1 )
0.030, wR2 ) 0.081, GOF 1.094, maximum (minimum) re-
sidual electron density 1.89 (-1.47) e Å-3, refined with
isotropic thermal parameters and with restraints, hydrogens
calculated and riding.13
P en ta ca r bon yl[4-eth oxy-6-(d icycloh exylp h osp h a n yl)-
1,2,3,3a -tetr a h ydr open ta len e-P ]tu n gsten (a n ti-14b), P en -
t a ca r b on yl[4-et h oxy-6-(d icycloh exylp h osp h a n yl)-1,2,3,
6a-tetrahydropentalene]tungsten (a nti-15b),P entacarbonyl-
[4-ethoxy-6-(dicyclohexylphosphanyl)-1,2,3,5-tetrahydropenta-
len e,-P ]tu n gsten (a n ti-16b), a n d P en ta ca r bon yl[3-(d icy-
cloh exylp h osp h a n yl)-3a ,5,6,6a -tetr a h yd r o-4H-p en ta len -
1-on e-P ]tu n gsten (a n ti-17b). Pentacarbonyl[3-(cyclopent-1-
X-ray crystal structure analysis of compound anti-16b:
formula C27H35O6PW, Mr ) 670.37, 0.4 × 0.3 × 0.2 mm, a )
14.206(2) Å, b ) 11.564(2) Å, c ) 18.103(3) Å, â ) 112.72(1)°,
V ) 2743.2(8) Å3, Fcalcd ) 1.623 g cm-3, µ ) 43.07 cm-1
,
empirical absorption correction via ψ scan data (0.933 e C e
0.999), Z ) 4, monoclinic, space group P21/n (No. 14), λ )
0.710 73 Å, T ) 223 K, ω/2θ scans, 5735 reflections collected
((h, -k, -l), (sin θ)/λ ) 0.62 Å-1, 5558 independent and 4039
observed reflections [I g 2σ(I)], 317 refined parameters, R1 )
0.027, wR2 ) 0.047, GOF 1.008, maximum (minimum) re-
sidual electron density 0.69 (-0.49) e Å-3, refined with
isotropic thermal parameters and with restraints, hydrogens
calculated and riding.13
1
3
a n ti-17b. H NMR (C6D6): δ 6.30 [1 H, d, J (P,H) ) 6 Hz,
2-H], 3.25 (1 H, m, 6a-H), 2.55 (1 H, m, 3a-H), 1.95-1.20 (27
H, m, 1-H2-3-H2, and 2 × CH2 cyclohexanyl). 13C NMR
(C6D6): δ 208.4 [Cq, 3J (P,C) ) 11 Hz, CdO], 198.2 [Cq, 4 C,

1380 Organometallics, Vol. 18, No. 8, 1999
Aumann et al.
2
2J (P,C) ) 7 Hz, cis-CO, (CO)5W], 198.5 [Cq, J (P,C) ) 22 Hz,
Ack n ow led gm en t. This work was supported by the
Deutsche Forschungsgemeinschaft and the Fonds der
Chemischen Industrie. We thank Barbara Hildmann for
experimental assistance.
trans-CO, (CO)5W], 173.0 [Cq, 1J (P,C) ) 16 Hz, C3], 141.5 [CH,
2J (P,C) ) 5 Hz, C2], 53.2 (CH, C6a), 51.3 [CH, 2J (P,C) ) 8
Hz, C3a], 38.7 and 38.0 [CH each, 1J (P,C) ) 22 and 21 Hz,
respectively, diastereotopic PCH], 32.3 (CH2, C4), 29.5 and 29.0
[CH2 each, 2J (P,C) ) 11 and 4 Hz, respectively, diastereotopic
3
PCHCH2], 28.5 (CH2, C5), 27.2 and 27.0 [CH2 each, J (P,C) )
Su p p or tin g In for m a tion Ava ila ble: Tables of positional
and displacement parameters, bond distances and angles, and
hydrogen coordinates for (3E)-5a , 6c, anti-11a , anti-16b, and
anti-17a . This material is available free of charge via the
Internet at http://pubs.acs.org.
9 Hz each, PCHCH2CH2], 26.2 (2 CH2, PCHCH2CH2CH2), 26.0
(CH2, C6). IR (hexane; cm-1 (%)): 2068.7 (20), 1973.0 (5),
1937.1 (100) [ν(CtO)], 1709.9 [ν(CdO)]. MS (70 eV; 184W, m/e
(%)): 642 (10) [M+], 614 (5), 586 (30), 558 (20), 530 (30), 502
(30) [M+ - 5 CO], 283 (10) [ligand], 171 (50), 57 (100). Anal.
Calcd for C25H31O6PW (642.3): C, 46.75; H, 4.86. Found: C,
46.66; H, 4.92.
OM9810394