Organophosphorus compounds, 139. - On the behavior of 5,8- bis(trimethylsilyl)cycloocta-1,3,6-triene in cycloaddition reactions and subsequent chemistry

Article abstract of DOI:10.1002/(sici)1099-0690(199905)1999:5<1041::aid-ejoc1041>3.0.co;2-b

Phosphaalkynes 2 and electron-deficient alkynes 11 readily react in a [4 + 2] cycloaddition process with 5,8-bis(trimethylsilyl)cycloocta-1,3,6-triene (8) in its bicyclic form 10 to furnish regioselectively the tricyclodecadienes 12 and 13, respectively. The phosphorus-containing compounds 12 exhibit structural features which make them suitable for homo- Diels-Alder reactions with electron-deficient acetylenes. A single crystal structure analysis of the homo-Diels-Alder adduct 14b confirmed the structure and relative configuration of the phophatricyclodecadienes 12. In solution the tricyclodecadienes 13 are prone to facile cycloreversion yielding the phthalic esters 15 and the cyclobutene 16. The latter is rapidly converted into the corresponding 1,3-butadiene 18, which can be trapped in a Diels- Alder/phospha-ene/Diels-Alder tandem reaction sequence by phosphaalkyne 2a. The phosphatricyclodecadiene 12 is thermally more stable; loss of cyclobutene 16 only occurs under FVP conditions to afford the λ³-phosphinine 22.

Full text of DOI:10.1002/(sici)1099-0690(199905)1999:5<1041::aid-ejoc1041>3.0.co;2-b

FULL PAPER
Organophosphorus Compounds, 139[°]
On the Behavior of 5,8-Bis(trimethylsilyl)cycloocta-1,3,6-triene in
Cycloaddition Reactions and Subsequent Chemistry
Michael A. Hofmann,[a] Anja Nachbauer,[a] Uwe Bergsträßer,[a] and Manfred Regitz*[a]
Dedicated to Professor Otto J. Scherer on the occasion of his 65th birthday
Keywords: Phosphaalkynes / Cycloadditions / Polycycles / Cage compounds / λ3-Phosphinines
Phosphaalkynes 2 and electron-deficient alkynes 11 readily
react in [4 2] cycloaddition process with 5,8-
bis(trimethylsilyl)cycloocta-1,3,6-triene (8) in its bicyclic form
10 to furnish regioselectively the tricyclodecadienes 12 and
13, respectively. The phosphorus-containing compounds 12
exhibit structural features which make them suitable for
configuration of the phophatricyclodecadienes 12. In solution
the tricyclodecadienes 13 are prone to facile cycloreversion
yielding the phthalic esters 15 and the cyclobutene 16. The
latter is rapidly converted into the corresponding 1,3-
butadiene 18, which can be trapped in a Diels–Alder/
phospha-ene/Diels–Alder tandem reaction sequence by
phosphaalkyne 2a. The phosphatricyclodecadiene 12 is
thermally more stable; loss of cyclobutene 16 only occurs
under FVP conditions to afford the λ3-phosphinine 22.
a
+
homo-Diels–Alder
reactions
with
electron-deficient
acetylenes. A single crystal structure analysis of the homo-
Diels–Alder adduct 14b confirmed the structure and relative
Introduction
Cycloaddition reactions play a major role in the chemis-
try of kinetically stabilized phosphaalkynes. Besides
[2 ϩ 1][2] and [3 ϩ 2] cycloaddition reactions[3], DielsϪ
Alder reactions are of particular interest since they provide
a simple access to numerous organophosphorus polycyclic
systems.
Thus, for example, the thermal reaction of cyclohexa-1,3-
diene with tert-butylphosphaacetylene 2 furnishes the stable
phosphabicyclo[2.2.2]octadiene 1[4]. Reaction of 2 with 1,3-
butadienes also gives rise to a primary [4 ϩ 2] cycloadduct;
however, a phosphacyclohexadiene of the type 3 can only
be isolated when the substituent R is 2,4,6-trimethylphen-
yl[5]. In all other cases, a series of subsequent reactions oc-
curs[6]. The phosphaalkyne 2 also readily participates in
DielsϪAlder reactions with kinetically stabilized, antiaro-
matic 4π-electron systems with formation of the Dewar 2-
phosphabenzenes 4[7]
.
We have now turned our attention to the reactions of
kinetically stabilized phosphaalkynes with cyclooctatrienes.
The latter are known to possess favorable prerequisites for
[4 ϩ 2] cycloadditions and, in analogy to the cyclooctatetra-
enes[8], to react exclusively from their bicyclic forms[9]. Ac-
cordingly, the reaction of cycloocta-1,3,6-triene or, cyclo-
octa-1,3,5-triene 5 with dimethyl acetylenedicarboxylate
Scheme 1
proceeds to furnish the tricyclic product 7 derived from the
bicyclic 1,3-diene form 6[10]
.
No concrete conclusions can be drawn about the stereo-
chemistry of the cyclobutane ring (syn- or anti-attack of the
dienophile) although mechanistic and steric considerations
would favor an anti arrangement. In the present report we
describe the reaction behavior of the easily accessible 5,8-
[°]
Part 138: Ref.[1]
[a]
Fachbereich Chemie der Universität Kaiserslautern,
Erwin-Schrödinger-Straße, D-67663 Kaiserslautern, Germany
Fax (internat.): ϩ49 (0)631/ 205-3921
E-mail: regitz@rhrk.uni-kl.de
bis(trimethylsilyl)cycloocta-1,3,6-triene (8)[11]
.
Eur. J. Org. Chem. 1999, 1041Ϫ1050
WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1999
1434Ϫ193X/99/0505Ϫ1041 $ 17.50ϩ.50/0
1041

M. A. Hofmann, A. Nachbauer, U. Bergsträßer, M. Regitz
FULL PAPER
Scheme 2
Results and Discussion
Diels؊Alder Reactions of Phosphaalkynes 2 and
Acetylenes 11 with 5,8-Bis(trimethylsilyl)cycloocta-
1,3,6-triene (8)
Thermolyses of 8 with the phosphaalkynes 2a؊c for 24
hours furnish the phosphatricyclodecadienes 12 almost ir-
respective of the stoichiometry. The tricyclic products are
isolated in the form of colorless needles in good yields
(52Ϫ64%) after separation by distillation and crystallization
from dichloromethane at Ϫ78 °C. Elemental analyses and
high resolution mass spectra unequivocally demonstrate a
1:1 stoichiometry for the adducts. The constitutions pro-
posed for products 12 are supported by their NMR spectra
and are discussed here in detail only for the tert-butyl de-
rivative 12a. The proposed stereochemisty was based on
considerations of the mechanism and confirmed by single
crystal X-ray crystallography after successful derivatization
(see below).
Scheme 3
The phosphaalkene unit in 12a is immediately apparent
from the characteristic low-field position of the signal in
the 31P{1H} NMR spectrum (δ ϭ 219.0); this value corre- The allylic signals of the two bridgehead protons at δ ϭ
sponds well with those of structurally related compounds[4]
.
4.01 (pseudo-quintet) and δ ϭ 3.95 (doubled double dou-
In the 13C{1H} NMR spectrum the signal of the phos- blet) are also characteristic. The protons of the cyclobutane
phaalkene carbon atom is markedly shifted to low field and unit give signals in the expected region between δ ϭ 0.95
appears as a doublet at δ ϭ 222.4 (1JC,P ϭ 45.0 Hz). The and 2.20.
other two sp2-hybridized carbon atoms C-9 and C-10 also
As unambiguously demonstrated by the discussion of the
give rise to doublet signals at δ ϭ 148.0 (2JC,P ϭ 6.4 Hz) spectral data, the kinetically stabilized phosphaalkynes
and δ ϭ 142.4 (3JC,P ϭ 11.2 Hz) and can be irrevocably 2a؊c do not react with the 1,3-diene unit originally present
assigned with the help of the proton coupled 13C-NMR in the cyclooctatriene 8. Instead, an initial, thermally in-
spectrum. The bridgehead carbon atoms C-1 and C-6 give duced sigmatropic [1,5]-hydrogen shift to furnish the conju-
signals at δ ϭ 49.9 and δ ϭ 49.8, both being split into dou- gated triene 9 occurs. Similar thermal isomerizations be-
blets. The carbon atom adjacent to phosphorus (C-1) exhib- tween cycloocta-1,3,6-trienes and cycloocta-1,3,5-trienes
1
its a JC,P coupling constant of 38.6 Hz while C-6 shows a are well known[12]. The subsequent electrocyclic ring clo-
2JC,P coupling of 9.6 Hz. The signal for the methylene car- sure which, in this case, leads to the bicyclic species 10 has
bon atom of the cyclobutane unit (C-4) appears at δ ϭ 21.5 been the subject of intensive investigations[13]. Although
while those for the methine carbon atoms occur at δ ϭ 39.0, eight different regio- and stereoisomers (without consider-
1
δ ϭ 35.5, and δ ϭ 22.9. The H-NMR spectrum recorded ation of enantiomers) are feasible as reaction products after
for the tricyclic product 12a is in complete harmony with the final [4 ϩ 2] cycloaddition, the reaction occurs with
the proposed constitution. Assignments of the skeletal pro- high selectivity. In the 31P{1H}-NMR spectrum of the reac-
tons, some of which exhibited complex splitting patterns, tion mixture a second signal appearing in the phospha-
were possible by means of a 2-D 1H,1H-COSY NMR alkene region (intensity ratio: ca. 9:1) is an indication for
experiment. The signal δ ϭ 6.65 can be securely assigned the formation of two isomers of which only the one de-
to the only present olefinic hydrogen atom 10-H on account scribed here can be isolated.
of its low-field position. The signal appears as a double
The exo-arrangement of the trimethylsilyl groups in 12 is
pseudo-triplet as a result of three homonuclear couplings. reasonable from steric considerations in the electrocyclic
1042
Eur. J. Org. Chem. 1999, 1041Ϫ1050

Organophosphorus Compounds, 139
FULL PAPER
ring closure as is the anti-arrangement of the cyclobutane yellow crystals. The molecular composition of the adducts
ring as a result of the more favorable approach geometry in can be deduced directly from their elemental analysis and
the [4 ϩ 2] cycloaddition.
mass spectral data while their constitutions are evident
The reactivity of the phosphaalkynes 2a-c towards the from the spectroscopic data as illustrated by the following
cyclooctatriene 8 can be compared with that of electron- discussion of the NMR data for the tert-butyl derivative
deficient alkynes. Accordingly, the acceptor-substituted 14a. The spectral patterns of 14b are more complicated as
alkynes 11a؊d, but not alkyl- or aryl-substituted alkynes, a result of the additional couplings with the fluorine atoms.
react with 8 under thermal conditions for several days to
Relative to that of the starting material 12a, the 31P{1H}
afford the tricyclodecadienes 13a؊d which can be isolated NMR spectrum of 14a reveals a significant shift of the sig-
as colorless solids or oils by column chromatography. The nal to higher field by 230.3 ppm which confirms the conver-
structures of these products are readily elucidated on the sion of the σ2λ3-phosphorus atom into a σ3λ3 state. The
basis of their spectroscopic data in comparison with those homo-DielsϪAlder reaction is regiospecific with formation
of the tricyclic phosphorus compounds 12. Exact assign- of a phosphacyclopentene unit. The opposite direction of
1
ments of the H-NMR signals are again possible with the addition can be excluded on the basis of the shift to even
help of a 1H,1H-COSY NMR experiment (on 13b as an higher field that would be expected for formation of a phos-
example). On account of the very good agreement between phirane unit[6][16]. The 13C{1H} NMR spectrum also sup-
the spectroscopic data of compounds 13 with those of 12, ports the proposed structure for 14a. Thus, the low-field
it is reasonable to assume that the all-carbon analogues region contains, in addition to signals for the carbonyl car-
have the same stereochemistry as the phosphorus com- bon atoms, those for the olefinic carbon atoms C-11 (δ ϭ
2
1
pounds.
165.4, JC,P ϭ 19.2 Hz) and C-12 (δ ϭ 144.7, JC,P ϭ 29.9
Hz), both as doublets on account of couplings with phos-
phorus. The skeletal carbon atom C-10 also gives a double
doublet signal at δ ϭ 52.9 (2JC,P ϭ 9.3 Hz), while the signal
at δ ϭ 58.1 (1JC,P ϭ 5.3 Hz) is assigned to the carbon atom
C-2. Although the 1JC,P coupling of C-2 is remarkably small
the assignment is unequivocally confirmed by the proton-
coupled 13C-NMR spectrum. Structurally related systems
also show comparably small couplings[15a]. The signal for
C-8 experiences a noticeable paramagnetic shift for a cyclo-
propane carbon atom on account of its proximity to the
phosphorus atom and the tert-butyl substitution (δ ϭ 47.7,
1JC,P ϭ 33.2 Hz). The remaining carbon atoms of the three-
membered ring as well as those of the cyclobutane ring give
Homo-Diels؊Alder Reactions of the
Phosphatricyclodecadienes 12a, b
The 1,4-diene units in the tricyclic phosphorus com-
pounds 12 described above possess the constitutional pre-
requisities for a homo-DielsϪAlder reaction. In contrast to
DielsϪAlder reactions, this type of reaction has been ob-
served only rarely in organic chemistry[14], although it is
not unusual in the chemistry of kinetically stabilized phos-
phaalkynes. In the latter case, mainly phosphaalkynes[15]
,
but also electron-poor alkynes[15c] have been employed as
the dienophile.
signals in the expected high-field region (δ ϭ 24.0Ϫ34.3)[17]
however, an exact assignment of the individual atoms is not
possible. The H-NMR spectrum contains signals for the
;
1
methyl protons of the ester groups, as well as for the tert-
butyl group and the trimethylsilyl substituents in the
1
characteristic regions. However, the H-NMR spectrum is
of little value for assignments of the skeletal protons. The
signals appear as complicated, in some cases overlapping,
multiplets as a result of numerous homonuclear and het-
eronuclear couplings so that an exact analysis is not pos-
sible.
A single crystal of the pentacyclic compound 14b suitable
for X-ray crystallography was obtained by crystallization
from n-pentane at Ϫ28 °C. The results of this structure
analysis not only supported the proposed regiochemistry of
the homo-DielsϪAlder reaction but also confirmed the
structures deduced for the tricyclic compounds 12 and 13.
The anti-arrangement of the cyclobutane ring as well as the
Scheme 4
When the polycyclic compounds 12a and 12b are heated exo-orientation of the trimethylsilyl group are clearly visible
at 140 °C in the presence of excess alkynes 11a, e the penta- (Figure 1). A conspicuous feature is the almost perfect equi-
cyclic products 14a؊c are formed. The reaction time varies lateral triangle formed by the atoms C7ϪC8ϪC9 in spite
between 4 and 72 hours. After workup by distillation or of the lack of symmetry in the molecule.
column chromatography and subsequent crystallization
Relative to other polycyclic compounds containing σ3λ3-
from n-pentane the homo-DielsϪAlder adducts are ob- phosphorus atoms[6,15c] the bond lengths and angles are all
tained in satisfactory yields (26Ϫ51%) as colorless or light in the expected ranges.
Eur. J. Org. Chem. 1999, 1041Ϫ1050
1043

M. A. Hofmann, A. Nachbauer, U. Bergsträßer, M. Regitz
FULL PAPER
Figure 1. Molecular structure of the phosphapentacyclododecene
14b as XP plot; thermal ellipsoids correspond to 50% probability.
Hydrogen atoms are omitted of reasons of clarity. Selected bond
Scheme 5
˚
lengths [A] and angles [°]: P1ϪC2 1.865(2), P1ϪC8 1.888(2),
P1ϪC12 1.846(2), C7ϪC8 1.511(3), C8ϪC9 1.511(3), C7ϪC9
1.519(3), C11ϪC12 1.347(3); C12ϪP1ϪC2 86.57(10), C2ϪP1ϪC8
89.70(9), C12ϪP1ϪC8 94.54(9), C7ϪC8ϪC9 60.35(13),
C8ϪC7ϪC9 59.82(13), C8ϪC9ϪC7 59.83(13).
formed. After workup by distillation and column chroma-
tography eluting with n-pentane the diphosphatricyclooc-
tene 19 is isolated in good yield (55% referred to the
amount of phosphaalkyne employed). Increasing the po-
larity of the eluent by adding diethyl ether subsequently fur-
nishes the phthalate 15a, unequivocally identified by
Subsequent Reactions of the Tricyclic Products 13a, b
In view of their structural similarities with norborna- NMR spectroscopy.
dienes, barrelenes, and bicyclo[2.2.2]octa-2,5-dienes, which
Both elemental analysis and mass spectroscopy confirm
have all been successfully used as dienes in homo-DielsϪ the 2:1 stoichiometry of the starting materials in the diphos-
Alder reactions[14a,14b,14d], we were prompted to attempt phatricyclooctene 19. The two doublets in the 31P{1H}
[2 ϩ 2 ϩ 2] cycloaddition reactions with the tricyclic com- NMR spectrum with a coupling constant of 157.6 Hz and
pounds 13. However, after heating of 13a for 2 days in the chemical shifts of δ ϭ Ϫ170.1 and δ ϭ Ϫ188.2 indicate
presence of an excess of the acetylenes 11a, e merely the the presence of a diphosphirane unit[6]. The 13C{1H} NMR
phthalic acid ester 15a was isolated. There was no evidence spectrum exhibits a signal pattern in full harmony with the
for the formation of the pentacyclic compound 17 or of the observed chemical shifts and coupling constants of pre-
homo-DielsϪAlder adduct with the opposite regiochemis- viously described diphosphatricyclooctenes[6]. The signal
try. When the polycyclic compounds 13a, b were heated at for C-2 is seen at δ ϭ 42.7 as a pseudo-triplet with two
1
140 °C for 3 days in the absence of the acetylene, column equal JC,P coupling constants of 46.6 Hz. The signals of
chromatographic workup furnished the phthalic acid esters the two carbon atoms C-6 and C-8 appear at δ ϭ 34.0
15a, b together with the 1,3-butadiene 18 as mixture of (E/ (1JC,P ϭ 54.3) and δ ϭ 62.1 (1JC,P ϭ 48.3), with that of C-
2
Z) isomers.
8 being additionally split into a double doublet by a JC,P
The phthalates 15a, b are easily identified on the basis of coupling of 3.4 Hz. The signal for the carbon atom C-5 at
their spectroscopic and analytical data. After chromato- δ ϭ 34.5 exhibits coupling to only one phosphorus atom
graphic separation, the volatile 1,3-butadienes (E)- and (Z)- (2JC,P ϭ 2.6 Hz). The 1H-NMR spectrum contains two sig-
18 can be detected in pentane solution by combined GC/ nals in the olefinic region (δ ϭ 6.20 and δ ϭ 5.36), with the
MS analysis. Distillative removal of the solvent made the signal at higher field being assigned to 4-H on account of
3
recording of a 1H-NMR spectrum possible and the data the two homonuclear couplings. The identical JH,H coup-
obtained agreed with those in the literature[18]. The inter- ling constants of 9.3 Hz confirm the adjacency of the two
mediate occurrence of the putative primary product, the protons. The hydrogen atom 5-H produces a multiplet sig-
cyclobutene 16, of the retro-DielsϪAlder reaction cannot nal at a chemical shift of 2.90 ppm typical for allylic pro-
be confirmed since no allylic resonances were observed. The tons.
ratio of the isomeric butadienes was determined to be 3:2
by integration.
From the mechanistic point of view the first step of the
reaction is most certainly again a retro-DielsϪAlder reac-
When the tricyclic compound 13a is subjected to ther- tion. Similar cycloreversion reactions of other tricyclooc-
molysis at 140 °C for seven days in the presence of the phos- tenes under flash vacuum pyrolysis conditions have been
phaalkyne 2a a new, phosphorus-containing product is reported[9b,9c,10,19]. In the present case the generated cyclo-
1044
Eur. J. Org. Chem. 1999, 1041Ϫ1050

Organophosphorus Compounds, 139
FULL PAPER
Scheme 6
butene 16 undergoes ring opening to the buta-1,3-diene 18. column chromatographic workup. Cyclobutene could not
Analogous electrocyclic reactions have often been de- be identified as the second pyrolysis product. Judging by
scribed, they are thermal conrotatory processes[20]. 1-Tri- the mild conditions for the synthesis of the phthalates
methylsilylbuta-1,3-diene 18 then reacts in a [4 ϩ 2] cyclo- 15a, b, the phosphatricyclodecadiene 12a exhibits a much
addition with one equivalent of the phosphaalkyne 2a to larger thermal stability than 13a. This is possibly due to the
afford the phosphacyclohexa-1,4-diene 20. Although a sec- lower aromatic character of the formed phosphinine[22]
ond regioisomer is feasible in this step Ϫ and has been
.
found with 1-methylbuta-1,3-diene to an extent of 15%[6b]
Ϫ the highly regioselective course of the reaction between
18 and the phosphaalkyne 2a can be demonstrated by
NMR spectroscopy. The individual reaction steps of the
tandem sequence (DielsϪAlder reaction, phospha-ene reac-
tion, intramolecular DielsϪAlder reaction) leading to the
Scheme 7
formation of 19 are well known from numerous investi-
gations on butadienes[6]
.
The 31P{1H} NMR spectrum of 22 provides the first indi-
cations for the existence of a phosphabenzene: the singlet
at δ ϭ 201.6 is in the typical region for a λ3-phosphin-
ine[4][23]. The chemical shifts and coupling constants ob-
served in the 13C{1H} NMR spectrum correlate very well
with those of other known phosphinines[4][23]. All aromatic
carbon signals occur as doublets with typically large down-
field shifts of C-2 (δ ϭ 184.9, 1JC,P ϭ 58.3 Hz) and C-6 (δ ϭ
When the phosphaalkyne 2a is allowed to react with a
sample of the (E)-buta-1,3-diene 18 prepared by a reported
procedure[21] (140 °C, pressure Schlenk tube, 7 days) the di-
phosphatricyclooctene 19 is also obtained after workup by
column chromatography and can be identified securely by
its analytical and spectral data. This lends further support
for the reaction pathway suggested here involving the gener-
ation of a free 1,3-butadiene.
1
159.0, JC,P ϭ 56.6 Hz). An exact assignment of signals to
the atoms C-3 and C-4 is not possible; they appear at δ ϭ
129.7 and δ ϭ 133.7. On account of the trimethylsilyl sub-
stitution the signal for C-5 is shifted down field to δ ϭ
144.1. The aromatic character of the phosphinine 22 is
clearly illustrated by the chemical shifts of the signals in the
1H-NMR spectrum. The three aromatic protons give sig-
nals at very low field between δ ϭ 7.5 and 9.1. The coupling
patterns are complicated and not completely resolved.
Preparation of the λ3-Phosphinine 22
The ease with which the tricyclic compounds 13a, b de-
compose to the phthalates 15a, b and cyclobutene 16
prompted us to undertake a more detailed study of the ther-
mal behavior of the analogous phosphorus-containing com-
pound 12a since it could provide a new access to a substi-
tuted λ3-phosphinine. In this context, it must be mentioned
that we have previously generated a phosphabenzene in a
similar way by cleavage of ethene from the phosphabicyclo-
[2.2.2]octa-2,5-diene 1 under flash vacuum pyrolysis con-
Complex Behavior of 12a
ditions[4]
.
When the phosphatricyclodecadiene 12a is treated with
When the phosphatricyclodecadiene 12a is subjected to an excess of the in situ generated pentacarbonyl-
flash vacuum pyrolysis at 650 °C/10Ϫ6 mbar, the previously tungsten · thf complex the η1-complex 23 is formed after 20
unknown λ3-phosphinine 22 is isolated in good yield after hours at room temperature and can be isolated as a yellow-
Eur. J. Org. Chem. 1999, 1041Ϫ1050
1045

M. A. Hofmann, A. Nachbauer, U. Bergsträßer, M. Regitz
FULL PAPER
of 2a. Yield: 0.45 g (1.28 mmol, 64%), b.p. 90 °C/10Ϫ2 mbar, m.p.
72 °C. Ϫ 1H NMR (C6D6): 0.01 [s, 9 H, Si(CH3)3], 0.11 [s, 9 H,
3
3
3
Si(CH3)3], 0.95 [ddd, JH,H ϭ 11.8 Hz, JH,H ϭ 7.7 Hz, JH,H
ϭ
4
6.3 Hz, 1 H, 3-H], 1.19 [d, JH,P ϭ 1.3 Hz, 9 H, C(CH3)3], 1.38
[dpt, JH,H ϭ 11.8 Hz, JH,H ϭ 11.8 Hz, JH,H ϭ 5.3 Hz, 1 H, 4-
2
3
3
2
3
3
H], 1.68 [ddd, JH,H ϭ 11.8 Hz, JH,H ϭ 8.7 Hz, JH,H ϭ 7.7 Hz,
1 H, 4-H], 2.08 [mc, JH,H ϭ 12.1 Hz, 3JH,H ϭ 8.7 Hz, JH,H ϭ 5.3
3
3
Scheme 8
Hz, 3JH,H ϭ 3.1 Hz, 4JH,H ϭ 1.5 Hz, 1 H, 5-H], 2.20 [ddd, 3JH,H ϭ
3
3
12.1 Hz, JH,H ϭ 6.3 Hz, JH,H ϭ 3.0 Hz, 1 H, 2-H], 3.95 [ddd,
2JH,P ϭ 19.9 Hz, JH,H ϭ 3.0 Hz, JH,H ϭ 1.5 Hz, 1 H, 1-H], 4.01
3
4
to-orange colored oil in high yield by column chromatogra-
phy.
3
3
3
[pquin, JH,H ϭ 6.5 Hz, JH,H ϭ 3.1 Hz, JH,P ϭ 3.1 Hz, 1 H, 6-
3
4
4
H], 6.65 [dpt, JH,H ϭ 6.5 Hz, JH,H ϭ 1.5 Hz, JH,H ϭ 1.5 Hz, 1
The selective end-on coordination of the metal fragment
to the phosphorus atom is clearly demonstrated by the ana-
lytical and spectral data of the complex. In the 31P{1H}
NMR spectrum the phosphorus signal is shifted by 56.6
ppm to higher field relative to the uncomplexed compound
12a. Particularly characteristic is the appearance of tung-
H, 10-H]. Ϫ 13C{1H} NMR (C6D6): Ϫ3.3 [s, Si(CH3)3], Ϫ2.3 [s,
3
Si(CH3)3], 21.5 [s, C-4], 22.9 [s, C-2, C-3, or C-5], 29.7 [d, JC,P
ϭ
12.9 Hz, C(CH3)3], 35.5 [d, JC,P ϭ 1.6 Hz, C-2, C-3, or C-5], 39.0
2
[d, JC,P ϭ 8.0 Hz, C-2, C-3, or C-5], 40.5 [d, JC,P ϭ 15.3 Hz,
2
1
C(CH3)3], 49.8 [d, JC,P ϭ 9.6 Hz, C-6], 49.9 [d, JC,P ϭ 38.6 Hz,
C-1], 142.4 [d, 3JC,P ϭ 11.2 Hz, C-10], 148.0 [d, 2JC,P ϭ 6.4 Hz, C-
9], 222.4 [d, 1JC,P ϭ 45.0 Hz, C-7]. Ϫ 31P{1H} NMR (C6D6): 219.0
1
sten satellites with a typical JP,W coupling constant of
228.3 Hz. The complexation has only slight influence on (s). Ϫ MS (EI, 70 eV); m/z (%): 350 (97) [M]ϩ, 335 (40) [M Ϫ
CH3]ϩ, 293 (40) [M Ϫ C4H9]ϩ, 277 (58) [M Ϫ Si(CH3)3]ϩ, 250 (10)
[M Ϫ C5H9P]ϩ, 235 (9) [M Ϫ C5H9P Ϫ CH3]ϩ, 73 (100)
[Si(CH3)3]ϩ, 57 (8) [C4H9]ϩ. Ϫ HRMS (EI, 70 eV): C19H35PSi2
calcd. 350.2015, found 350.2015.
the 13C- and 1H-NMR data of the skeletal atoms. The only
1
conspicuous feature is the disappearance of the JC,P coup-
ling in the signal for C-1. A similar trend has previously
been observed in homo-DielsϪAlder reactions of 12a. In
addition to the signals for the skeleton of 12a the 13C-NMR
spectrum now contains signals for the carbon atoms of the
axial and equatorial carbonyl ligands at low field (δ ϭ 196.4
and δ ϭ 199.6). Also typical CO valency vibrations of the
terminal carbonyl ligands are seen in the IR spectrum at
7-(1-Adamantyl)-3,9-bis(trimethylsilyl)-8-phosphatricyclo-
[4.2.2.02,5]deca-7,9-diene (12b): From 0.58 g (2.32 mmol) of 8 and
0.57 g (3.2 mmol) of 2b. Yield: 0.59 g (1.38 mmol, 60%), b.p.
150 °C/10Ϫ2 mbar, m.p. 140 °C. Ϫ 1H NMR (C6D6): Ϫ0.03 [s, 9 H,
Si(CH3)3], 0.14 [s, 9 H, Si(CH3)3], 0.98 [mc, 1 H, 3-H], 1.43 [dpt,
3
3
2JH,H ϭ 11.8 Hz, JH,H ϭ 11.8 Hz, JH,H ϭ 5.4 Hz, 1 H, 4-H],
ν˜ ϭ 2070 cmϪ1 and 1940 cmϪ1
.
1.6Ϫ1.9 [m, 16 H, adamantyl-H and 4-H], 2.07 [mc, 1 H, 5-H], 2.23
3
3
3
[ddd, JH,H ϭ 11.9 Hz, JH,H ϭ 6.1 Hz, JH,H ϭ 3.0 Hz, 1 H, 2-
2
3
H], 4.00 [mc, JH,P ϭ 19.5 Hz, 1 H, 1-H], 4.08 [pquin, JH,H ϭ 6.5
3
3
3
Experimental Section
Hz, JH,H ϭ 3.1 Hz, JH,P ϭ 3.1 Hz, 1 H, 6-H], 6.64 [d, JH,H
ϭ
6.5 Hz, 1 H, 10-H]. Ϫ 13C{1H} NMR (CDCl3): Ϫ3.6 [s, Si(CH3)3],
Ϫ2.4 [s, Si(CH3)3], 21.0 [s, C-4], 22.3 [s, C-2, C-3, or C-5], 28.6 [s,
C-3Ј, C-5Ј, C-7Ј], 34.7 [s, C-2, C-3, or C-5], 36.9 [s, C-4Ј, C-6Ј, C-
All reactions were carried out under an argon atmosphere in oven-
dried glassware. The solvents were anhydrous and stored under ar-
1
gon. Ϫ H NMR and 13C NMR: Bruker AC 200 and AMX 400;
3
10Ј], 38.5 [d, JC,P ϭ 8.6 Hz, C-2, C-3 or C-5], 41.9 [d, JC,P ϭ 13.4
chemical shifts are referenced to the solvent as internal standard.
2
31P NMR: Bruker AC 200 (80.8 Hz); 85% H3PO4 as external
Hz, C-2Ј, C-8Ј or C-9Ј], 42.4 [d, JC,P ϭ 13.4 Hz, C-1Ј], 47.9 [d,
Ϫ
2JC,P ϭ 10.5 Hz, C-6], 49.1 [d, JC,P ϭ 38.2 Hz, C-1], 141.9 [d,
1
standard. Ϫ IR: PerkinϪElmer 1310 series FTIR spectrometer. Ϫ
MS: Finnigan MAT 90. Ϫ GC/MS: HP 6890 series with MSD;
column: HP-5MS capillary column 30 m ϫ 250 µm. Ϫ Elemental
analyses: PerkinϪElmer EA240. Ϫ Melting points: Mettler FP61
(heating rate 2 °C/min), uncorrected. Ϫ Analytical TLC: Plastic
sheets, silica gel, Polygram SIL G/UV254, MacheryϪNagel. Ϫ CC:
Merck silica gel (0.063Ϫ0.2 mm). Ϫ Bulb-to-bulb distillation:
Büchi GKR 50 apparatus; the temperatures stated are oven tem-
peratures.
Compounds 2a[24], 2b[25], 2c[26], 8[11], 11c[27], 11d[28], and (E)-18[21]
were prepared by published methods. All other starting materials
were obtained from commercial suppliers and used without
further purification.
3JC,P ϭ 11.4 Hz, C-10], 147.5 [d, JC,P ϭ 6.7 Hz, C-9], 223.4 [d,
2
1JC,P ϭ 43.9 Hz, C-7]. Ϫ 31P{1H} NMR (CDCl3): 218.6 (s). Ϫ MS
(EI, 70 eV); m/z (%): 428 (97) [M]ϩ, 413 (8) [M Ϫ CH3]ϩ, 355 (47)
[M Ϫ Si(CH3)3]ϩ, 293 (16) [M Ϫ C10H15]ϩ, 135 (62) [C10H15]ϩ, 73
(100) [Si(CH3)3]ϩ. Ϫ HRMS (EI, 70 eV): C25H41PSi2 calcd.
428.2484, found 428.2484.
7-(1,1-Dimethylpropyl)-3,9-bis(trimethylsilyl)-8-phosphatricyclo-
[4.2.2.02,5]deca-7,9-diene (12c): From 1.00 g (3.99 mmol) of 8 and
0.56 g (4.91 mmol) of 2c. Yield: 0.75 g (2.06 mmol, 52%), b.p.
1
90 °C/10Ϫ2 mbar, m.p. 57 °C. Ϫ H NMR (C6D6): Ϫ0.01 [s, 9 H,
3
Si(CH3)3], 0.10 [s, 9 H, Si(CH3)3], 0.72 [t, JH,H ϭ 7.6 Hz, 3 H,
C(CH3)2(CH2CH3)], 0.92 [mc, 1 H, 3-H], 1.13 [d, J ϭ 1.5 Hz, 3 H,
C(CH3)2(CH2CH3)], 1.21 [d, J ϭ 1.7 Hz, 3 H, C(CH3)2(CH2CH3)],
1.3Ϫ1.75 [m, 4 H, 4-H, 4-H- and C(CH3)2(CH2CH3)], 2.0Ϫ2.2 [m,
2 H, 2-H and 5-H], 3.85Ϫ4.0 [m, 2 H, 1-H and 6-H], 6.60 [dpt,
3JH,H ϭ 6.3 Hz, J ϭ 1 Hz, J ϭ 1 Hz, 1 H, 10-H]. Ϫ 13C{1H} NMR
(C6D6): Ϫ3.3 [s, Si(CH3)3], Ϫ2.3 [s, Si(CH3)3], 9.2 [s,
C(CH3)2(CH2CH3)], 21.6 [s, C-4], 23.0 [s, C-2, C-3, or C-5], 27.1
General Procedure for the Preparation of the Phosphatricyclodeca-
dienes 12a؊c: The appropriate phosphaalkyne 1 and the cycloocta-
1,3,6-triene 8 were heated in 5 mL toluene to 90 °C for 24 hours.
in a Schlenk pressure tube. The reaction mixture was allowed to
cool to room temperature and subsequently all volatile components
were removed in vacuo. The residue was purified by bulb-to-bulb
distillation. Crystallization from CH2Cl2 at Ϫ78 °C yielded 12a؊c
as colorless crystals.
3
3
[d, JC,P ϭ 17.8 Hz, C(CH3)2(CH2CH3)], 28.0 [d, JC,P ϭ 12.7 Hz,
3
C(CH3)2(CH2CH3)], 33.5 [d, JC,P ϭ 8.5 Hz, C(CH3)2(CH2CH3)],
35.4 [s, C-2, C-3, or C-5], 38.9 [d, JC,P ϭ 8.5 Hz, C-2, C-3, or C-
7-tert-Butyl-3,9-bis(trimethylsilyl)-8-phosphatricyclo[4.2.2.02,5]deca-
7,9-diene (12a): From 0.5 g (2.0 mmol) of 8 and 0.32 g (3.2 mmol)
5], 43.6 [d, JC,P ϭ 13.6 Hz, C(CH3)2(CH2CH3)], 49.5 [d, JC,P ϭ
2
2
10.2 Hz, C-6], 49.9 [d, 1JC,P ϭ 39.0 Hz, C-1], 142.6 [d, 3JC,P ϭ 11.0
1046
Eur. J. Org. Chem. 1999, 1041Ϫ1050

Organophosphorus Compounds, 139
FULL PAPER
2
1
Hz, C-10], 147.9 [d, JC,P ϭ 7.6 Hz, C-9], 220.8 [d, JC,P ϭ 45.8 (0.52 mmol, 26%), colorless oil, which was crystallized from n-pen-
Hz, C-7]. Ϫ 31P{1H} NMR (C6D6): 225.1 (s). Ϫ MS (EI, 70 eV);
tane at Ϫ78°C, b.p. 160 °C/10Ϫ2 mbar, m.p. 63 °C. Ϫ 1H NMR
m/z (%): 364 (18) [M]ϩ, 349 (10) [M Ϫ CH3]ϩ, 335 (11) [M Ϫ (C6D6): Ϫ0.12 [s, 9 H, Si(CH3)3], Ϫ0.10 [s, 9 H, Si(CH3)3],
C2H5]ϩ, 293 (13) [M Ϫ C5H11]ϩ, 291 (15) [M Ϫ Si(CH3)3]ϩ, 250 0.85Ϫ0.90 [m, 2 H, 3-H and 4-H], 1.30Ϫ1.45 [m, 1 H, 4-H],
(1) [M Ϫ C6H11P]ϩ, 73 (100) [Si(CH3)3]ϩ, 71 (7) [C5H11]ϩ. Ϫ CHN: 1.50Ϫ1.60 [m, 1 H, 5-H], 1.70Ϫ1.80 [m, 1 H, 2-H], 3.20Ϫ3.30 [m,
3
C20H37PSi2 (364.66), calcd. C 65.88, H 10.23; found C 65.37, H 1 H, 1-H], 3.70Ϫ3.80 [m, 1 H, 6-H], 6.01 [ddd, JH,H ϭ 5.8 Hz,
4
10.11.
4JH,H ϭ 1.6 Hz, JH,H ϭ 0.9 Hz, 1 H, 10-H]. Ϫ 13C{1H} NMR
(C6D6): Ϫ3.6 [s, Si(CH3)3], Ϫ2.4 [s, Si(CH3)3], 19.8 [s, C-2, C-3, or
C-5], 20.8 [s, C-4], 35.9 [s, C-2, C-3, or C-5], 37.6 [s, C-2, C-3, or
C-5], 46.5 [s, C-1 or C-6], 48.8 [s, C-1 or C-6], 114.7 [s, CN], 114.8
[s, CN], 130.6 [s, C-7 or C-8], 131.5 [s, C-7 or C-8], 139.8 [s, C-10],
146.4 [s, C-9]. Ϫ MS (EI, 70 eV); m/z (%): 326 (1) [M]ϩ, 311 (5)
[M Ϫ CH3]ϩ, 273 (49), 253 (6) [M Ϫ Si(CH3)3]ϩ, 185 (8), 126 (9),
73 (100) [Si(CH3)3]ϩ. Ϫ IR (KBr): ν˜ ϭ 2961, 1637, 1404, 1262,
General Procedure for the Preparation of the Tricyclodecadienes
13a؊d: A toluene solution of the cycloocta-1,3,6-triene 8 and the
appropriate acetylene 11a؊d was heated under magnetic stirring to
90 °C in a Schlenk pressure tube. After cooling to room tempera-
ture the solvent was removed under reduced pressure. The residue
was purified by column chromatography (with the exception of 13c,
which was filtered over Celite to remove insoluble materials prior
to chromatography).
1096, 1021, 801, 701 cmϪ1
.
7,8-Dibenzoyl-3,9-bis(trimethylsilyl)tricyclo[4.2.2.02,5]deca-7,9-diene
(13d): From 0.57 g (2.3 mmol) of 8 and 0.61 g (2.6 mmol) of 11d
in 5 mL of toluene. Stirring for 72 hours. Chromatography on silica
gel (40 ϫ 2 cm) with dichloromethane/n-pentane, 2:1, and sub-
sequently on silica gel (75 ϫ 3 cm) with n-pentane/diethyl ether,
4:1. Yield: 0.19 g (0.39 mmol, 17%), colorless oil, b.p. 160 °C/10Ϫ2
Dimethyl 3,9-Bis(trimethylsilyl)tricyclo[4.2.2.02,5]deca-7,9-diene-7,8-
dicarboxylate (13a): From 1.03 g (4.11 mmol) of 8 and 0.75 mL
(0.65 g, 4.57 mmol) of 11a in 7 mL of toluene. Stirring for 48 hours.
Chromatography on silica gel (40 ϫ 2 cm) with petroleum ether/
diethyl ether, 15:1. Yield: 1.18 g (3.01 mmol, 73%), colorless oil,
which was crystallized from n-pentane, b.p. 120 °C/10Ϫ2 mbar, m.p.
98 °C. Ϫ 1H NMR (C6D6): Ϫ0.02 [s, 9 H, Si(CH3)3], 0.16 [s, 9
H, Si(CH3)3], 0.85Ϫ0.95 [m, 1 H, 3-H], 1.25Ϫ1.35 [m, 1 H, 4-H],
1.60Ϫ1.70 (m, 1 H, 4-H], 2.25Ϫ2.35 [m, 2 H, 2-H and 5-H], 3.47
[s, 3 H, CO2CH3], 3.49 [s, 3 H, CO2CH3], 4.10Ϫ4.20 [m, 1 H, 1-
1
mbar. Ϫ H NMR (CDCl3): 0.01 [s, 9 H, Si(CH3)3], 0.17 [s, 9 H,
Si(CH3)3], 0.80Ϫ0.90 [m, 1 H, 3-H], 1.35Ϫ1.50 [m, 1 H, 2-H],
1.75Ϫ1.85 [m, 1 H, 5-H], 2.35Ϫ2.55 [m, 2 H, 4-H (2ϫ)], 4.20Ϫ4.30
[m, 2 H, 1-H and 6-H], 6.97 [m, 1 H, 10-H], 7.05Ϫ7.20 [m, 6 H,
m- and p-C6H5], 7.30Ϫ7.35 [m, 4 H, o-C6H5]. Ϫ 13C{1H} NMR
(CDCl3): Ϫ3.5 [s, Si(CH3)3], Ϫ1.8 [s, Si(CH3)3], 20.7 [s, C-2, C-3,
or C-5], 21.6 [s, C-4], 36.6 [s, C-2, C-3, or C-5], 38.3 [s, C-2, C-3,
or C-5], 45.9 [s, C-1 or C-6], 48.6 [s, C-1 or C-6], 128.1Ϫ138.4 [8s,
C6H5], 142.2 [s, C-10], 146.7 [s, C-7, C-8 or C-9], 148.1 [s, C-7, C-
8 or C-9], 149.9 [s, C-7, C-8 or C-9], 195.1 [s, C6H5CϭO], 196.2 [s,
C6H5CϭO]. Ϫ MS (EI, 70 eV); m/z (%): 484 (2) [M]ϩ, 431 (100)
[M Ϫ Si(CH3)3]ϩ, 359 (27), 281 (7), 105 (9), 73 (39) [Si(CH3)3]ϩ. Ϫ
IR (CCl4): ν˜ ϭ 2954, 2899, 1783, 1726, 1649, 1551, 1448, 1249,
3
4
H], 4.30Ϫ4.35 [m, 1 H, 6-H], 6.62 [dd, JH,H ϭ 5.7 Hz, JH,H
ϭ
1.7 Hz, 1 H, 10-H]. Ϫ 13C{1H} NMR (C6D6): Ϫ3.5 [s, Si(CH3)3],
Ϫ2.0 [s, Si(CH3)3], 20.4 [s, C-2, C-3, or C-5], 21.5 [s, C-4], 36.8 [s,
C-2, C-3, or C-5], 38.4 [s, C-2, C-3, or C-5], 44.7 [s, C-1 or C-6],
47.3 [s, C-1 or C-6], 51.5 [s, CO2CH3], 51.6 [s, CO2CH3], 140.2 [s,
C-7 or C-8], 142.2 [s, C-10], 143.5 [s, C-7 or C-8], 147.3 [s, C-9],
165.9 [s, CO2CH3], 166.8 [s, CO2CH3]. Ϫ MS (EI, 70 eV); m/z (%):
392 (7) [M]ϩ, 339 (33), 251 (13), 235 (100), 73 (39) [Si(CH3)3]ϩ. Ϫ
IR (film): ν˜ ϭ 3030, 2951, 2851, 1716, 1633, 1583, 1435, 1346, 1305,
1260, 1218, 1128, 1075, 1042, 834, 749 cmϪ1. Ϫ CHN: C20H32O4Si2
(392.64), calcd. C 61.18, H 8.21; found C 60.00, H 8.19.
712 cmϪ1
.
General Procedure for the Preparation of the Phosphapentacyclodo-
decenes 14a؊c: The appropriate phosphatricyclodecadiene 12 and
alkyne 11 were dissolved in toluene in a Schlenk pressure tube and
heated to 140 °C. After completion of the reaction the volatile com-
ponents were removed in vacuo. The residue was purified by bulb-
to-bulb distillation (14a, b) or column chromatography (14c) and
subsequent crystallization from n-pentane.
Di-tert-butyl 3,9-Bis(trimethylsilyl)tricyclo[4.2.2.02,5]deca-7,9-diene-
7,8-dicarboxylate (13b): From 0.5 g (2.0 mmol) of 8 and 0.68 g (3.0
mmol) of 11b in 5 mL of toluene. Stirring for 48 hours. Chromatog-
raphy on silica gel (120 ϫ 7 cm) with petroleum ether/diethyl ether,
10:1 (RF ϭ 0.33 with n-pentane/diethyl ether, 15:1). Yield: 0.78 g
(1.64 mmol, 82%), colorless oil, which was crystallized from n-pen-
tane, b.p. 130 °C/10Ϫ2 mbar, m.p. 74 °C. Ϫ 1H NMR (C6D6): Ϫ0.11
[s, 9 H, Si(CH3)3], 0.07 [s, 9 H, Si(CH3)3], 0.75Ϫ0.85 [m, 1 H, 3-
H], 1.15Ϫ1.35 [m, 1 H, 4-H], 1.41 [s, 9 H, CO2C(CH3)3], 1.45 [s, 9
Dimethyl 8-tert-Butyl-4,10-bis(trimethylsilyl)-1-phosphapentacyclo-
[6.4.0.02,10.03,6.07,9]dodec-11-ene-11,12-dicarboxylate (14a): From
0.27 g (0.77 mmol) of 12a and 0.14 g (0.99 mmol) of 11a in 3 mL
of toluene. Stirring for 4 hours. Bulb-to-bulb distillation at 160 °C/
10Ϫ2 mbar and crystallization from n-pentane at Ϫ78 °C afforded
0.19 g (0.39 mmol, 51%) of 14a as a pale yellow solid (m.p. 128 °C).
H, CO2C(CH3)3], 1.50Ϫ1.65 [m, 1 H, 4-H], 2.20Ϫ2.35 [m, 2 H, 2-
3
H and 5-H], 4.10Ϫ4.15 [m, 2 H, 1-H and 6-H], 6.59 [dd, JH,H
ϭ
5.9 Hz, JH,H ϭ 1.7 Hz, 1 H, 10-H]. Ϫ 13C{1H} NMR (C6D6):
Ϫ3.9 [s, Si(CH3)3], Ϫ2.3 [s, Si(CH3)3], 20.1 [s, C-2, C-3, or C-5],
21.3 [s, C-4], 27.8 [s, CO2C(CH3)3], 27.9 [s, CO2C(CH3)3], 36.6 [s,
C-2, C-3, or C-5], 38.2 [s, C-2, C-3, or C-5], 44.5 [s, C-1 or C-6],
47.6 [s, C-1 or C-6], 80.4 [s, CO2C(CH3)3], 80.4 [s, CO2C(CH3)3],
139.5 [s, C-7 or C-8], 142.3 [s, C-10], 144.0 [s, C-7 or C-8], 146.7 [s,
C-9], 164.4 [s, CO2C(CH3)3], 165.6 [s, CO2C(CH3)3]. Ϫ MS (CI,
isobutane): m/z: 477 [M ϩ H]ϩ. Ϫ IR (KBr): ν˜ ϭ 2977, 2942, 2851,
1734, 1706, 1640, 1584, 1479, 1456, 1368, 1250, 1171, 1072, 1034,
984, 834, 752 cmϪ1. Ϫ CHN: C26H44O4Si2 (476.80), calcd. C 65.50,
H 9.30; found C 64.91, H 9.00.
4
Ϫ
1H NMR (C6D6): Ϫ0.08 [s, 9 H, Si(CH3)3], 0.43 [s, 9 H,
Si(CH3)3], 0.97 [s, 9 H, C(CH3)3], 1.46 [ddd, J ϭ 7.4 Hz, J ϭ 4.3
Hz, J ϭ 2.6 Hz, 1 H], 1.69 [d, J ϭ 7.3 Hz, 1 H], 1.8Ϫ2.0 [m, 4 H],
2.39 [mc, 1 H], 2.65 [mc, 1 H], 3.39 [s, 3 H, CO2CH3], 3.61 [s, 3
H, CO2CH3]. Ϫ 13C{1H} NMR (C6D6): Ϫ3.8 [s, Si(CH3)3], 1.1 [s,
Si(CH3)3], 24.0 [d, JC,P ϭ 13.3 Hz, C-3, C-4, C-6, C-7, or C-9], 25.3
[s, C-5], 28.2 [d, JC,P ϭ 7.3 Hz, C-3, C-4, C-6, C-7, or C-9], 29.7
3
[d, JC,P ϭ 4.6 Hz, C(CH3)3], 31.5 [d, JC,P ϭ 3.3 Hz, C-3, C-4, C-
2
6, C-7, or C-9], 32.3 [d, JC,P ϭ 10.0 Hz, C(CH3)3], 32.4 [d, JC,P
ϭ
3.3 Hz, C-3, C-4, C-6, C-7, or C-9], 34.3 [d, JC,P ϭ 15.9 Hz, C-3,
1
7,8-Dicyano-3,9-bis(trimethylsilyl)tricyclo[4.2.2.02,5]deca-7,9-diene
C-4, C-6, C-7, or C-9], 47.7 [d, JC,P ϭ 33.2 Hz, C-8], 51.5 [s,
2
(13c): From 0.5 g (2.0 mmol) of 8 and 0.24 g (3.2 mmol) of 11c in CO2CH3], 51.8 [s, CO2CH3], 52.9 [d, JC,P ϭ 9.3 Hz, C-10], 58.1
5 mL of toluene. Stirring for 48 hours. Chromatography on silica
gel (40 ϫ 2 cm) with dichloromethane/n-pentane, 3:1. Yield: 0.17 g
[d, 1JC,P ϭ 5.3 Hz, C-2], 144.7 [d, 1JC,P ϭ 29.9 Hz, C-12], 165.4 [d,
2JC,P ϭ 19.2 Hz, C-11], 169.4 [s, CO2CH3], 170.6 [s, CO2CH3]. Ϫ
Eur. J. Org. Chem. 1999, 1041Ϫ1050
1047

M. A. Hofmann, A. Nachbauer, U. Bergsträßer, M. Regitz
FULL PAPER
1
1
31P{1H} NMR (C6D6): Ϫ11.3 (s). Ϫ MS (EI, 70 eV); m/z (%): 492
9.3 Hz, C-10], 57.3 [d, JC,P ϭ 5.9 Hz, C-2], 144.5 [d, JC,P ϭ 29.7
(15) [M]ϩ, 477 (33) [M Ϫ CH3]ϩ, 435 (9) [M Ϫ C4H9]ϩ, 419 (6) [M Hz, C-12], 165.5 [d, JC,P ϭ 19.5 Hz, C-11], 169.5 [s, CO2CH3],
Ϫ Si(CH3)3]ϩ, 392 (11) [M Ϫ C5H9P]ϩ, 73 (100) [Si(CH3)3]ϩ, 57 170.5 [s, CO2CH3]. Ϫ 31P{1H} NMR (C6D6): Ϫ13.2 (s). Ϫ MS (EI,
2
(14) [C4H9]ϩ. Ϫ HRMS: C25H41O4PSi2 calcd. 492.2281, found
70 eV); m/z (%): 570 (2) [M]ϩ, 555 (8) [M Ϫ CH3]ϩ, 497 (2) [M Ϫ
492.2282. Ϫ IR (n-pentane): ν˜ ϭ 1739, 1722 cmϪ1. Ϫ CHN: Si(CH3)3]ϩ, 435 (2) [M Ϫ C5H10]ϩ, 135 (79) [C10H15]ϩ, 73 (100)
C25H41O4PSi2 (492.74), calcd. C 60.94, H 8.39; found C 60.85, H
8.28.
[Si(CH3)3]ϩ. Ϫ HRMS: C31H47O4PSi2 calcd. 570.2751, found
570.2750. Ϫ IR (n-pentane): ν˜ ϭ 1739, 1722 cmϪ1
.
Thermolysis of the Tricyclodecadienes 13a, b ؊ General Procedure:
A toluene solution of the respective tricyclodecadiene 13 was
heated to 140 °C in a Schlenk pressure tube under a positive pres-
sure of 5 bar. After 3 days the reaction mixture was subjected to
column chromatography without previous evaporation of the vol-
atile components. Upon elution with n-pentane a mixture of (E)-
and (Z)-18 was obtained. After elution of the reaction solvent
(toluene) the polarity of the eluent was increased and the phthalic
esters 15 were obtained as colorless liquids.
8-tert-Butyl-11,12-bis(trifluoromethyl)-4,10-bis(trimethylsilyl)-1-
phosphapentacyclo[6.4.0.02,10.03,6
.
07,9]dodec-11-ene (14b): From
0.28 g (0.8 mmol) of 12a and 0.24 g (1.48 mmol) of 11e in 2.5 mL
of toluene. Stirring for 3 days. Chromatography on silica gel (35 ϫ
2 cm) with n-pentane afforded 0.13 g (0.25 mmol, 32%) of 14b as
a colorless oil (RF ϭ 0.5), from which colorless crystals were ob-
tained (n-pentane, Ϫ25 °C); b.p. 110 °C/10Ϫ2 mbar, m.p. 94 °C. Ϫ
1H NMR (C6D6): Ϫ0.08 [s, 9 H, Si(CH3)3], 0.42 [d, J ϭ 1.5 Hz, 9
H, Si(CH3)3], 0.86 [s, 9 H, C(CH3)3], 1.25Ϫ1.40 [m, 1 H], 1.55Ϫ1.65
[m, 1 H], 1.8Ϫ2.0 [m, 4 H], 2.25Ϫ2.35 [m, 1 H,], 2.55Ϫ2.65 [m, 1
Dimethyl 4-(Trimethylsilyl)phthalate (15a): From 133.4 mg (0.34
mmol) of 13a in 0.5 mL of toluene. Column chromatography on
silica gel (25 ϫ 1.5 cm) yielded 74.5 mg (0.28 mmol, 82%) of 15a
as a colorless liquid (RF ϭ 0.46 with n-pentane/diethyl ether, 1:1);
H]. Ϫ 13C{1H} NMR (CDCl3): Ϫ3.8 [s, Si(CH3)3], 2.7 [q, JC,F
ϭ
3.4 Hz, Si(CH3)3], 24.4 [d, JC,P ϭ 14.4 Hz, C-3, C-4, C-6, C-7, or
C-9], 24.9 [s, C-5], 28.1 [d, JC,P ϭ 10.2 Hz, C-3, C-4, C-6, C-7, or
3
1
b.p. 80 °C/10Ϫ2 mbar. Ϫ H NMR (C6D6): 0.08 [s, 9 H, Si(CH3)3],
C-9], 29.6 [d, JC,P ϭ 5.1 Hz, C(CH3)3], 31.2 [d, JC,P ϭ 3.4 Hz, C-
3
3
3, C-4, C-6, C-7, or C-9], 31.7 [d, JC,P ϭ 9.3 Hz, C(CH3)3], 32.6
3.59 [s, 3 H, CO2CH3], 3.59 [s, 3 H, CO2CH3], 7.38 [dd, JH,H
ϭ
4
3
[s, C-3, C-4, C-6, C-7, or C-9], 34.5 [d, JC,P ϭ 17.0 Hz, C-3, C-4,
7.6 Hz, JH,H ϭ 1.2 Hz, 1 H, 5-H], 7.63 [dd, JH,H ϭ 7.6 Hz,
1
2
5JH,H ϭ 0.5 Hz, 1 H, 6-H], 7.96 [dd, JH,H ϭ 1.2 Hz, JH,H ϭ 0.5
Hz, 1 H, 3-H]. Ϫ 13C{1H} NMR (CDCl3): Ϫ1.6 [s, Si(CH3)3], 52.3
[s, CO2CH3], 52.4 [s, CO2CH3], 127.8 [s, C-3, C-5, or C-6], 131.0
[s, C-1 or C-2], 131.6 [s, C-1 or C-2], 133.1 [s, C-3, C-5, or C-6],
135.7 [s, C-3, C-5, or C-6], 145.1 [s, C-4], 167.8 [s, CO2CH3], 168.4
[s, CO2CH3]. Ϫ MS (EI, 70 eV); m/z (%): 266 (8) [M]ϩ, 251 (100)
[M Ϫ CH3]ϩ, 235 (12) [M Ϫ 2 CH3 Ϫ H]ϩ, 219 (11), 191 (10), 73
(5) [Si(CH3)3]ϩ. Ϫ IR (film): ν˜ ϭ 2999, 2954, 2845, 1732, 1435,
1290, 1131, 1114, 1069, 873, 839, 754 cmϪ1. Ϫ CHN: C13H18O4Si
(266.37), calcd. C 58.62, H 6.81; found C 58.42, H 6.78.
4
5
C-6, C-7, or C-9], 47.4 [d, JC,P ϭ 31.4 Hz, C-8], 53.6 [d, JC,P
ϭ
10.2 Hz, C-10], 59.6 [d, 1JC,P ϭ 3.4 Hz, C-2], 120Ϫ129 [m, 2 CF3],
152.0 [mc, C-12], 158.5 [mc, C-11]. Ϫ 31P{1H} NMR (C6D6): 2.0
(q, JP,F ϭ 22.9 Hz). Ϫ MS (EI, 70 eV); m/z (%): 512 (12) [M]ϩ,
3
497 (5) [M Ϫ CH3]ϩ, 439 (7) [M Ϫ Si(CH3)3]ϩ, 251 (16), 77 (12),
73 (100) [Si(CH3)3]ϩ, 57 (27) [C4H9]ϩ. Ϫ IR (toluene): ν˜ ϭ 2954,
2910, 1600, 1448, 1288, 1256, 1176, 1145, 834, 737 cmϪ1. Ϫ CHN:
C25H35F6PSi2 (512.66), calcd. C 53.89, H 6.88; found C 53.65, H
6.88.
Crystal Data and Summary of Data Collection Parameters for
14b:[29] Diffractometer STOE Imaging Plate Diffraction System;
radiation: Mo-Kα; C23H35F6PSi2; M ϭ 512.66 g·molϪ1; T ϭ 20°C;
Di-tert-butyl 4-(Trimethylsilyl)phthalate (15b): From 249.2 mg (0.49
mmol) of 13b in 0.5 mL of toluene. Column chromatography on
silica gel (20 ϫ 2.5 cm) yielded 131.7 mg (0.38 mmol, 78%) of 15b
as a colorless liquid (RF ϭ 0.6 with n-pentane/diethyl ether, 4:1).
¯
Crystal size 0.35 ϫ 0.25 ϫ 0.20 mm; triclinic P1; a ϭ 9.893(2), b ϭ
˚
10.380(2), c ϭ 13.523(3) A, α ϭ 88.16(3), β ϭ 87.13(3), γ ϭ
1H NMR (CDCl3): 0.19 [s, 9 H, Si(CH3)3], 1.64 [s, 9 H,
3
75.16(3)°; V ϭ 1340.4(5) A ; Z ϭ 2; dcalcd. ϭ 1.270 Mg·mϪ3; µ ϭ
˚
Ϫ
3
0.243 mmϪ1; F(000) ϭ 540; Θ range 2.54Ϫ26.00°; index ranges:
Ϫ12 Յ h Յ 12, Ϫ12 Յ k Յ 12, Ϫ16 Յ l Յ 16; no. of reflections
collected: 16659; no. of independent reflections: 4818; structure
solution by direct methods (SHELXS-86[30]); structure refinement
by full-matrix least-sqaures (SHELXL-93[31]); R indices (all data):
R1 ϭ 0.0538, wR2 ϭ 0.1459; final R indices [I > 2σ(I)]: R1 ϭ
0.0469, wR2 ϭ 0.1302; GoF on F2: 1.022.
CO2C(CH3)3], 1.65 [s, 9 H, CO2C(CH3)3], 7.42 [dd, JH,H ϭ 7.6
4
3
Hz, JH,H ϭ 1.2 Hz, 1 H, 5-H], 7.75 [d, JH,H ϭ 7.6 Hz, 1 H, 6-
H], 7.96 [s, 1 H, 3-H]. Ϫ 13C{1H} NMR (CDCl3): Ϫ1.4 [s,
Si(CH3)3], 28.0 [s, CO2C(CH3)3], 28.0 [s, CO2C(CH3)3], 81.6 [s,
CO2C(CH3)3], 81.7 [s, CO2C(CH3)3], 127.8 [s, C-3, C-5, or C-6],
130.1 [s, C-1 or C-2], 133.0 [s, C-1 or C-2], 133.6 [s, C-3, C-5, or
C-6], 135.1 [s, C-3, C-5, or C-6], 144.1 [s, C-4], 166.7 [s,
CO2C(CH3)3], 167.4 [s, CO2C(CH3)3]. Ϫ MS (CI, isobutane); m/z:
351 [M ϩ H]ϩ. Ϫ IR (film): ν˜ ϭ 2976, 2904, 1853, 1782, 1723,
Dimethyl 8-(1-Adamantyl)-4,10-bis(trimethylsilyl)-1-phosphapenta-
cyclo[6.4.0.02,10.03,6.07,9]dodec-11-ene-11,12-dicarboxylate
(14c):
1456, 1368, 1302, 1252, 1135, 1068, 905, 843, 752 cmϪ1
.
From 0.30 g (0.7 mmol) of 12b and 0.14 g (0.99 mmol) of 11a in 5
mL of toluene. Stirring for 18 hours. Bulb-to-bulb distillation at
200 °C/10Ϫ2 mbar and crystallization from n-pentane at Ϫ78 °C
afforded 0.10 g (0.18 mmol, 26%) of 14c as a pale yellow solid. Ϫ
1H NMR (C6D6): Ϫ0.49 [s, 9 H, Si(CH3)3], 0.49 [s, 9 H, Si(CH3)3],
1.5Ϫ2.1 [m, 21 H, adamantyl and 6 H], 2.44 [mc, 1 H], 2.68 [mc, 1
H], 3.42 [s, 3 H, CO2CH3], 3.62 [s, 3 H, CO2CH3]. Ϫ 13C{1H}
(E)- and (Z)-1-Trimethylsilylbuta-1,3-diene (18): Thermolysis of
133.4 mg (0.34 mmol) of 15a yielded after column chromatography
on silica gel (25 ϫ 1.5 cm; RF ϭ 0.73 with n-pentane), removal of n-
pentane, and bulb-to-bulb distillation (60°C/45 mbar) 19 mg (0.15
mmol, 44%) of 18 (ratio of stereoisomers ca. 3:2 as determined by
1
integration of the H NMR spectrum). GC/MS analysis of the n-
pentane solution of 18 afforded two signals with RT ϭ 5.53 min
NMR (C6D6): Ϫ3.8 [s, Si(CH3)3], 1.2 [s, Si(CH3)3], 24.0 [d, JC,P
13.6 Hz, C-3, C-4, C-6, C-7, or C-9], 25.4 [s, C-5], 28.3 [d, JC,P
ϭ
and RT ϭ 5.70 min, each with m/z ϭ 126 [M]ϩ.
ϭ
7.6 Hz, C-3, C-4, C-6, C-7, or C-9], 29.2 [s, C-3Ј, C-5Ј, C-7Ј], 30.5
2,8-Di-tert-butyl-6-trimethylsilyl-1,7-diphosphatricyclo[3.2.1.02,7]-
[d, JC,P ϭ 3.4 Hz, C-3, C-4, C-6, C-7, or C-9], 30.7 [d, JC,P ϭ 3.4 oct-3-ene (19): To a solution of 470 mg (1.2 mmol) of 13a in 5 mL
Hz, C-3, C-4, C-6, C-7, or C-9], 33.6 [d, JC,P ϭ 9.3 Hz, C-1Ј], 34.4 of toluene 280 µl (2 mmol) of 2a were added. The reaction mixture
[d, JC,P ϭ 15.3 Hz, C-3, C-4, C-6, C-7, or C-9], 37.1 [s, C-4Ј, C-6Ј,
was heated to 140 °C in a Schlenk pressure tube under a positive
pressure of 5 bar. The reaction was complete after 7 days (monitor-
ing by 31P NMR). Removal of the volatile components and bulb-
3
1
C-10Ј], 42.2 [d, JC,P ϭ 5.1 Hz, C-2Ј, C-8Ј, C-9Ј], 48.7 [d, JC,P
ϭ
33.1 Hz, C-8], 51.5 [s, CO2CH3], 51.9 [s, CO2CH3], 52.5 [d, 2JC,P ϭ
1048
Eur. J. Org. Chem. 1999, 1041Ϫ1050

Organophosphorus Compounds, 139
FULL PAPER
3
4
3
to-bulb distillation of the residue (100 °C/10Ϫ2 mbar) yielded 390 Hz, JH,H ϭ 3.1 Hz, JH,H ϭ 1.4 Hz, 1 H, 1-H], 6.52 [d, JH,H
mg crude product. Pure 19 was isolated by column chromatography
(silica gel, 40 ϫ 2 cm, n-pentane, RF ϭ 0.47). Further elution with
ϭ
6.5 Hz, 1 H, 10-H]. Ϫ 13C{1H} NMR (C6D6): Ϫ3.6 [s, Si(CH3)3],
Ϫ2.1 [s, Si(CH3)3], 21.3 [s, C-4], 21.9 [s, C-2, C-3, or C-5], 30.1 [d,
n-pentane/diethyl ether yielded 190 mg (0.85 mmol, 71%) dimethyl 3JC,P ϭ 12.1 Hz, C(CH3)3], 36.3 [d, JC,P ϭ 8.0 Hz, C-2, C-3, or C-
2
phthalate of 15a. Yield of diphsophatricyclooctene 19: 180 mg
(0.55 mmol, 55%) as a colorless solid; m.p. 126 °C
5], 39.5 [d, JC,P ϭ 20.1 Hz, C-2, C-3, or C-5], 40.8 [d, JC,P ϭ 4.0
2
Hz, C(CH3)3], 51.6 [d, JC,P ϭ 9.6 Hz, C-6], 59.5 [s, C-1], 142.6 [d,
3JC,P ϭ 20.9 Hz, C-10], 146.9 [d, JC,P ϭ 10.4 Hz, C-9], 196.4 [d,
2
Alternative Route: A mixture of phosphaalkyne 2a (178 µL, 1.26
mmol) and 80 mg (0.63 mmol) of (E)-18, which was prepared by a
literature procedure[21], in 1.5 mL of toluene was stirred at 140 °C
for 7 days. After evaporation of excess phosphaalkyne and solvent,
column chromatography (silica gel, 16 ϫ 2.5 cm, n-pentane) yielded
32.8 mg (0.1 mmol, 16%) of 19 as a colorless solid. Ϫ 1H NMR
2JC,P ϭ 8.8 Hz, JC,W ϭ 126.1 Hz, COeq], 199.6 [d, JC,P ϭ 28.9
1
2
Hz, COax], 211.6 [d, JC,P ϭ 41.0 Hz, C-7]. Ϫ 31P{1H} NMR
1
1
(C6D6): 162.4 [s, JP,W ϭ 228.3 Hz]. Ϫ MS (EI, 70 eV); m/z (%):
674 (54) [M]ϩ, 618 (5) [M Ϫ 2 CO]ϩ, 590 (4) [M Ϫ 3 CO]ϩ, 562
(4) [M Ϫ 4 CO]ϩ, 534 (9) [M Ϫ 5 CO]ϩ, 492 (18), 463 (17) [M Ϫ
5 CO Ϫ Si(CH3)3]ϩ, 462 (74) [M Ϫ 4 CO Ϫ C5H9P]ϩ, 432 (15), 73
(100) [Si(CH3)3]ϩ, 57 (10) [C4H9]ϩ. Ϫ HRMS (EI, 70 eV):
C24H35O5PSi2W calcd. 674.1276, found 674.1271. Ϫ IR (film): ν˜ ϭ
2956, 2868, 2368, 2070, 1940, 1587, 1475, 1361, 1246, 1154, 1079,
4
(C6D6): 0.06 [d, JH,P ϭ 0.7 Hz, 9 H, Si(CH3)3], 0.54 [mc, 1 H, 6-
H or 8-H], 1.00 [s, 9 H, C(CH3)3], 1.10 [s, 9 H, C(CH3)3], 1.20 [mc,
3
1 H, 6-H or 8-H], 2.90 [mc, 1 H, 5-H], 5.36 [dd, JH,H ϭ 9.3 Hz, ,
3JH,H ϭ 8.0 Hz, 1 H, 4-H], 6.20 [d, JH,H ϭ 9.3 Hz, 1 H, 3-H]. Ϫ
3
879, 832, cmϪ1
.
3
13C{1H} NMR (C6D6): 0.1 [d, JC,P ϭ 3.4 Hz, Si(CH3)3], 29.2 [pt,
3
3JC,P
ϭ
3JC,P ϭ 6.4 Hz, 2-C(CH3)3], 31.7 [d, JC,P ϭ 6.8 Hz, 8-
C(CH3)3], 33.2 [d, 2JC,P ϭ 8.5 Hz, 8-C(CH3)3], 34.0 [d, 1JC,P ϭ 54.3
Hz, C-6], 34.5 [d, JC,P ϭ 2.6 Hz, C-5], 34.9 [pt, JC,P ϭ JC,P
10.2 Hz, 2-C(CH3)3], 42.7 [pt, JC,P ϭ JC,P ϭ 46.6 Hz, C-2], 62.1
2
2
2
Acknowledgments
ϭ
1
1
We thank the Fonds der Chemischen Industrie for generous finan-
cial support. We are grateful to the Deutsche Forschungsgemein-
schaft (Graduate College Phosphorus as Connecting Link between
Various Chemical Disciplines) for generous financial support and
a post-graduate grant (to A. N.). We are also indebted to Prof.
J. Hahn (University of Cologne) for recording the 2D-1H NMR
spectrum of 12a.
1
2
[dd, JC,P ϭ 48.3 Hz, JC,P ϭ 3.4 Hz, C-8], 121.3 [s, C-4], 129.4 [s,
C-3]. Ϫ 31P{1H} NMR (CDCl3): Ϫ170.1 [d, JP,P ϭ 157.6 Hz, P-1
1
1
or P-7], Ϫ188.2 [d, JP,P ϭ 157.6 Hz, P-1 or P-7]. Ϫ MS (EI, 70
eV); m/z (%): 326 (43) [M]ϩ, 311 (6) [M Ϫ CH3]ϩ, 269 (10) [M Ϫ
C4H9]ϩ, 225 (85) [M Ϫ C5H10P]ϩ, 73 (63) [Si(CH3)3]ϩ, 57 (7)
[C4H9]ϩ, 44 (46), 32 (100). Ϫ IR (toluene): ν˜ ϭ 3019, 1614, 1604,
1494, 1460, 738, 734, 722, 698, 693 cmϪ1. Ϫ CHN: C17H32P2Si
(326.47), calcd. C 62.54, H 9.88; found C 62.01, H 9.80.
[1]
Part 138: A. Mack, U. Bergsträßer, G. J. Reiß, M. Regitz, Eur.
2-tert-Butyl-5-trimethylsilyl-λ3-phosphinine (22): A sample of 12a
(260 mg, 0.74 mmol) was slowly evaporated in a flash vacuum pyro-
lysis apparatus (oven temperature: 650 °C, 5·10Ϫ6 mbar; Pyrex glass
tube: 23 ϫ 1 cm). The yellow-orange reaction products were con-
densed into a cold trap which was cooled with liquid nitrogen.
Chromatography (silica gel, 25 ϫ 2 cm, n-pentane, RF ϭ 0.59)
yielded 80 mg (0.36 mmol, 49%) of 22 as a colorless solid (m.p.
49 °C). Ϫ 1H NMR (C6D6): 0.18 [s, 9 H, Si(CH3)3], 1.42 [d, 4JH,P ϭ
1.2 Hz, 9 H, C(CH3)3], 7.50Ϫ7.75 [m, 2 H], 8.90Ϫ9.05 [m, 1 H]. Ϫ
J. Org. Chem. 1999, 587Ϫ596.
[2] [2a]
O. Wagner, M. Ehle, M. Regitz, Angew. Chem. 1989, 101,
227Ϫ229; Angew. Chem. Int. Ed. Engl. 1989, 28, 225Ϫ226. Ϫ
[2b]
E. Niecke, R. Streubel, M. Nieger, D. Stalke, Angew. Chem.
1989, 101, 1708Ϫ1710; Angew. Chem. Int. Ed. Engl. 1989, 28,
1673.
[3]
For an overview see: M. Regitz in Multiple Bonds and Low Co-
ordination in Phosphorus Chemistry (Eds. M. Regitz, O.
Scherer), Thieme, Stuttgart 1990, pp. 68Ϫ77.
[4]
W. Rösch, M. Regitz, Z. Naturforsch. 1986, 41b, 931Ϫ933.
[5]
A. Mack, E. Pierron, T. Allspach, U. Bergsträßer, M. Regitz,
Synthesis 1998, 1305Ϫ1313.
3
13C{1H} NMR (CDCl3): Ϫ1.2 [s, Si(CH3)3], 32.7 [d, JC,P ϭ 11.7
[6] [6a]
E. P. O. Fuchs, W. Rösch, M. Regitz, Angew. Chem. 1987,
Hz, C(CH3)3], 38.7 [d, 2JC,P ϭ 18.9 Hz, C(CH3)3], 129.7 [d, 3JC,P ϭ
99, 1058Ϫ1059; Angew. Chem. Int. Ed. Engl. 1987, 26,
1011Ϫ1012. Ϫ
2
2
[6b]
11.7 Hz, C-4], 133.7 [d, JC,P ϭ 19.8 Hz, C-3], 144.1 [d, JC,P
ϭ
H. Heydt, U. Bergsträßer, R. Fäßler, E.
1
1
Fuchs, N. Kamel, T. Mackewitz, G. Michels, W. Rösch, M. Re-
gitz, P. Mazerolles, C. Laurent, A. Faucher, Bull. Soc. Chim. Fr.
1995, 132, 652Ϫ668. Ϫ [6c] W. Fiedler, O. Löber, U. Bergsträßer,
M. Regitz, Eur. J. Org. Chem. 1999, 363Ϫ372.
12.6 Hz, C-5], 159.0 [d, JC,P ϭ 56.6 Hz, C-6], 184.9 [d, JC,P
ϭ
58.3 Hz, C-2]. Ϫ 31P{1H} NMR (C6D6): 201.6 [s]. Ϫ MS (EI, 70
eV); m/z (%): 224 (15) [M]ϩ, 209 (51) [M Ϫ CH3]ϩ, 73 (100)
[Si(CH3)3]ϩ, 57 (4) [C4H9]ϩ. Ϫ IR (KBr): ν˜ ϭ 2955, 1456, 1372,
[7]
J. Fink, W. Rösch, U.-J. Vogelbacher, M. Regitz, Angew. Chem.
1986, 98, 265Ϫ266; Angew. Chem. Int. Ed. Engl. 1986, 25,
280Ϫ282.
1305, 1247, 1089, 1035, 899, 839, 752 cmϪ1
.
[8]
[9]
{7-tert-Butyl-3,9-bis(trimethylsilyl)-8-phosphatricyclo[4.2.2.02,5]-
deca-7,9-diene}pentacarbonyl-tungsten (23): solution of
G. Schröder, Cyclooctatetraen, Verlag Chemie, Weinheim 1965.
[9a] W. Sanne, O. Schlichting, Angew. Chem. 1963, 75, 156Ϫ161.
A
[9b]
Ϫ
D. A. Bak, K. Conrow, J. Org. Chem. 1966, 31,
[9c]
pentacarbonyltungsten · thf was prepared by irradiation (HPK, 125
W, Phillips) of a solution of 0.28 g (0.8 mmol) of hexacarbonyltung-
sten in 60 mL of THF for 45 min. To this solution 0.23 g (0.66
mmol) of 12a in 5 mL of THF were added and the mixture was
stirred at room temperature for 20 hours. The solvent was then
removed under reduced pressure and the yellow residue was chro-
matographed with n-pentane (silica gel, 27 ϫ 2.5 cm, RF ϭ 0.47)
after filtration over Celite. After elution of 30 mg of excess hexacar-
bonyltungsten, complex 23 was isolated as a yellow oil (360 mg,
0.53 mmol, 80%). Ϫ 1H NMR (C6D6): 0.01 [s, 9 H, Si(CH3)3], 0.12
[s, 9 H, Si(CH3)3], 0.80Ϫ0.95 [m, 1 H, 3-H], 1.15 [s, 9 H, C(CH3)3],
1.20Ϫ1.30 [m, 1 H, 4-H], 1.60Ϫ1.70 [m, 1 H, 4-H], 2.00Ϫ2.15 [m,
3958Ϫ3965. Ϫ
1963, 85, 2298Ϫ2302.
J. L. Kice, T. S. Cantrell, J. Am. Chem. Soc.
[10]
[11]
A. C. Cope, A. C. Haven, F. L. Ramp, E. R. Trumbull, J. Am.
Chem. Soc. 1952, 74, 4867Ϫ4871.
N. C. Burton, F. G. N. Cloke, S. C. P. Joseph, H. Karamallakis,
A. A. Sameh, J. Organomet. Chem. 1993, 462, 39Ϫ43.
[12] [12a]
[12b]
W. R. Roth, Liebigs Ann. Chem. 1964, 671, 25Ϫ31. Ϫ
W. R. Roth, B. Peltzer, Liebigs Ann. Chem. 1965, 685,
56Ϫ74.
[13] [13a]
R. Huisgen, A. Dahmen, H. Huber, J. Am. Chem. Soc.
[13b]
1967, 89, 7130Ϫ7131. Ϫ
R. Huisgen, G. Boche, A. Dah-
men, W. Hechtl, Tetrahedron Lett. 1968, 50, 5215Ϫ5219. Ϫ
[13c] R. Huisgen, A. Dahmen, H. Huber, Tetrahedron Lett. 1969,
19, 1461Ϫ1464.
[14] [14a]
[14b]
E. F. Ullmann, Chem. Ind. 1958, 1173Ϫ1174. Ϫ
C. G.
3
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