Bidentate phosphorus baskets by intramolecular phosphinidene addition

Article abstract of DOI:10.1002/chem.200501531

Intramolecular phosphinidene addition to the C=C bond of Mo-complexed, seven-membered phosphorus heterocycles affords three novel [(diphos)Mo(CO) ₄] complexes (18-20). The three bidentate phosphorus baskets differ in the composition of the seve

Full text of DOI:10.1002/chem.200501531

FULL PAPER
DOI: 10.1002/chem.200501531
Bidentate Phosphorus Baskets by Intramolecular Phosphinidene Addition
Sander G. A. van Assema,[a] Andreas W. Ehlers,[a] Frans J. J. de Kanter,[a]
Marius Schakel,[a] Anthony L. Spek,[b] Martin Lutz,[b] and Koop Lammertsma*[a]
Abstract: Intramolecular phosphini-
dene addition to the C=C bond of Mo-
complexed, seven-membered phospho-
rus heterocycles affords three novel
[(diphos)Mo(CO)4]complexes ( 18–20).
The three bidentate phosphorus bas-
kets differ in the composition of the
seven-membered ring: one of the phos-
phorus atoms is flanked by CH2,
NCH3, or O. The unsaturated tetrahy-
drophosphepine precursors are synthe-
sized by either ring-closing metathesis
(C and N derivatives) or by a cycliza-
tion sequence (O derivative). The crys-
tal structures of the nitrogen- (19) and
oxygen-containing (20) baskets have
relatively small P-Mo-P angles of
76.240(13)8 and 77.626(12)8, respective-
ly, and complex 20 has slightly short-
Keywords:
compounds · P ligands · phosph-
inidene complexes phosphorus
heterocycles
A
·
cage
A
·
ꢀ
ened Mo P bond lengths.
AHCTREUNG
ꢀ
ꢀ
Introduction
structure of 2 has an extremely small P Mo P bond angle
of 69.732(16)8. Both these highly stable complexes have a
chelating phosphirane ring, and they were synthesized by in-
tramolecular cycloaddition of a transient phosphinidene
(RPMLn) to the double bond of the five-membered phosp-
Transition-metal complexes with polycyclic bidentate phos-
phane ligands are rare. They are of interest because the
structural rigidity of the ligand can affect both the access to,
and the electronic properties of, the transition metal, which
are aspects relevant to the design of catalysts. Two such mo-
lybdenum complexes are known, one (1) with a tricyclic
ligand and the other (2) with a bicyclic ligand.[1] Their phos-
phorus atoms are separated by two C2 bridges. The crystal
hole ring (L) using the transition-metal in cis-[RPMo-
[2]
(CO)4L]as template. Mathey et al.
have used a related
double intermolecular cycloaddition (to cyclooctene) for the
synthesis of 3. The BABAR-Phos (4) system developed by
Grützmacher et al.,[3] another polycyclic ligand with a phos-
phirane ring, has demonstrated its potential in catalysis. This
very stable ligand has the advantage of being reformed from
the metallaphosphetane, which otherwise usually leads to
loss of catalyst.[4]
[a]S. G. A. van Assema, Dr. A. W. Ehlers, Dr. F. J. J. de Kanter,
Dr. M. Schakel, Prof. Dr. K. Lammertsma
Department of Organic and Inorganic Chemistry
Faculty of Sciences, Vrije Universiteit
De Boelelaan 1083, 1081 HV, Amsterdam (The Netherlands)
Fax : (+31)20-598-7488
E-mail: K.Lammertsma@few.vu.nl
[b]Prof. Dr. A. L. Spek, Dr. M. Lutz
Bijvoet Center for Biomolecular Research, Crystal and Structural
Chemistry
In the present study we report new molybdenum com-
plexes with larger polycyclic bidentate phosphorus ligands
that include N and O atoms embedded in the hydrocarbon
frame that separates the phosphorus atoms. As starting
Utrecht University
Padualaan 8, 3584 CH, Utrecht (The Netherlands)
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ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4333

point we use the P-phenyl derivatives of the seven-mem-
bered rings (L) 2,3,6,7-tetrahydro-1H-phosphepine (5), 1,3-
dimethyl-2,3,4,7-tetrahydro-1H-1,3,2-diazophosphepine (6),
and 4,7-dihydro-1,3,2-dioxaphosphepine (7). Our strategy in-
chelate Mo complex 12 (44%; see Scheme 2) was formed to-
gether with smaller amounts of the bistetrahydrophosphe-
pine (<10%) and bisphosphole complexes (<10%), as sug-
gested by their resonances at d=25.1 and 33.5 ppm, respec-
tively, in the 31P NMR spectrum. Product 12 shows two dou-
2
blets at d=26.1 and 32.7 ppm with a normal JP, P coupling
constant of 24.0 Hz. The IR carbonyl frequencies at 2021,
1915, and 1890 cmꢀ1 and the 13C NMR carbonyl resonances
at d=215.5, 215.2, and 210.1 ppm confirm that the crucial
cis configuration at the transition-metal center is main-
tained.
Next, the phosphole ring must be converted into the phos-
phinidene precursor for the critical cycloaddition to the ole-
finic bond of the seven-membered ring ligand. Precursor 15
was obtained (63%) in the usual manner by a Diels–Alder
reaction with dimethylacetylene dicarboxylate (Scheme 2).
Again, the complex maintains its cis configuration.
volves ligating the ring in a cis fashion in [PMo(CO)4L]and
converting the P ligand to a terminal phosphinidene com-
plex for subsequent intramolecular cycloaddition to the ole-
finic bond of the seven-membered ring (L) to build the new
“baskets” 18, 19, and 20. Relevant to the synthesis is wheth-
er the cycloaddition is influenced by the ring size of ligand
L and whether heteroatoms will influence this process, for
example, by competing ylide formation.
Results and Discussion
The three systems are discussed separately, with each sec-
tion starting with the synthesis of the seven-membered ring.
Of the possible phosphinidene
precursors,[5] we use the estab-
lished 7-phosphanorbornadiene
Scheme 2. Synthesis of the 7-phosphanorbornadiene–Mo complexes.
unit 8.
Diphos basket 18: The starting
Product 15 shows two doublets in the 31P NMR spectrum
at d=25.7 and 251.9 ppm for the phosphepine and 7-phos-
phanorbornadiene P atoms, respectively, with a normal JP, P
coupling constant of 26.1 Hz. The large downfield shift from
phosphole to 7-phosphanorbornadiene is normal.
point is the synthesis of
5
2
(Scheme 1), the key step of
which is the ring-closing meta-
thesis (RCM) of diene 9 (ob-
tained from reaction of phenyl-
Heating complex 15 in toluene at 808C gave, after ther-
mal decomposition of the 7-phosphanorbornadiene ligand to
generate the transient phosphinidene complex, the desired
cycloadduct 18 as the sole isolable, high-melting (m.p. 194–
1958C) product in 66% yield (Scheme 3). The 31P NMR
spectrum exhibits two doublets (2JP, P =38.4 Hz), one at d=
+16.5 ppm for the phosphepane ring and one at d=
ꢀ150.5 ppm for the phosphirane ring. Mo(CO)5-complexed
phosphiranes have more deshielded resonances in the range
phosphonic dichloride with two equivalents of allylmagnesi-
um bromide),[6] in the presence of 6% of the Grubbsꢁ first-
generation catalyst [RuCl
2(PCy3)2=CHPh]( 11).[7] Reduction
A
of the resulting oxide 10 at 808C with phenylsilane[8] gave
the desired tetrahydrophosphepine 5 without side products,
as shown by the clean conversion of the 31P NMR resonance
at d=+41.7 ppm of the starting material into one at d=
ꢀ13.5 ppm.
Because 5 is sensitive toward oxidation it was not isolated,
but was treated directly with cis-[Mo(CO)4(piperidine)2][9]
and 3,4-dimethyl-1-phenylphosphole. The expected mixed-
Scheme 1. Synthesis of tetrahydrophosphepine 5.
Scheme 3. Phosphinidene addition to give novel diphos baskets 18–20.
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Chem. Eur. J. 2006, 12, 4333 – 4340

Bidentate Phosphorus Baskets
FULL PAPER
d=ꢀ115 to ꢀ135 ppm,[10,11] while those for
1
(d=
The cis CO ligand was then exchanged for 3,4-dimethyl-1-
phenylphosphole by UV irradiation (THF) to give the Mo
complex 13 (28% yield, 51% conversion). Full conversion
was not possible because of the limited stability of 13 under
these reaction conditions. Diels–Alder reaction of the
phosphole ligand with dimethylacetylene dicarboxylate
yielded the phosphinidene precursor complex 16 (55%),
and thermal decomposition of this complex at 708C in tol-
uene gave the diphosphane basket 19 in low yield (24%) as
colorless crystals (m.p. 83–848C) along with minor unidenti-
ꢀ101.7 ppm) and 2 (d=ꢀ79.7 ppm) are at still lower field
2
with no (1) or only a small JP,P coupling constant (2,
8.1 Hz). The 31P NMR chemical shift of 15.4 ppm for the
phospholane ring of 2 is similar to that of the phosphepane
ring of 18, but here also the ring-size effect seems to be
present when comparing the chemical shifts of the “basket”
and its precursor: 18 shows an upfield shift of 9.2 ppm com-
2
pared to 15 and an increase of 12.3 Hz for JP, P, while ring
2
closure leading to 2 gives an 18.3-Hz decrease in JP, P and a
smaller upfield shift of 4.2 ppm for the five-membered-ring
phosphorus. No strain effects are evident from the 13C NMR
parameters of the hydrocarbon frame of 18 or in comparison
with 2.
fied products (d
(31P)=135 and 148 ppm). The much lower
A
yield of 19 as compared to 18 indicates a lower selectivity
for the cycloaddition, possibly due to the competing forma-
tion of an ylide due to interaction of the transient phosphi-
nidene complex with the nitrogen atom. Related P,N-ylides
are known as reactive intermediates[14] that are not amena-
ble to isolation, and we expect this to be the case here too.
The ring closure of 16 to 19 causes an upfield shift of only
Diphos basket 19: The synthesis of the seven-membered
ring structure 6 was similar to that for 5 (Scheme 4), follow-
ing a procedure described for the related phosphona-
2.4 ppm (to d
(31P)=140.0 ppm) for the seven-membered
A
2
heterocycle, although the 32.1-Hz increase in the JP, P cou-
pling constant to 58.7 Hz is large. However, the NMR spec-
troscopic data provide little additional insight.
The formation of 19 was confirmed by a single-crystal X-
ray structure determination (Figure 1). The distorted octahe-
dral conformation around Mo, with a small Mo1-C22-O4
bond angle (170.42(16)8) and a larger than usual P2-Mo1-
C22 bond angle (99.07(5)8) is due to interaction of the C5-
methyl group at N1 with the C22-O4 carbonyl group. The P-
Mo-P bite angle of 76.240(13)8 is significantly larger than
for the tighter 2 (69.732(16)8) and is only 2.68 smaller than
Scheme 4. Synthesis of phosphine oxide 22.
mides.[12] While, N-methylallylamine (2 equiv) reacted with
PhP(O)Cl2 to give 21 (67%), and whereas ring-closing meta-
thesis with the Grubbsꢁ first-generation catalyst 11 yielded
oxide 22 (78%), no reduction occurred with PhSiH3 or
HSiCl3/Et3N. Therefore, the approach outlined in Scheme 5
was followed. In this route, N-methylallylamine is treated
with dichlorophenylphosphane, instead of the oxide, to give
23 (95%), and the stabilizing transition-metal group, using
freshly prepared [Mo(CO)
5(MeCN)]or [Mo(CO) 6],[13] is
A
added (23 ! 24 (30%)) before the RCM step (24 ! 25
(97%)). The 31P NMR spectrum shows that the introduction
of Mo(CO)5 is frustrated by the formation of unidentified
products (peaks at d=138, 146, and 150 ppm) in a nearly
equal combined ratio to the main product 23 (d=23.7 ppm).
Figure 1. Structure of 19 (displacement ellipsoid plot drawn at the 50%
probability level). Hydrogen atoms have been omitted for clarity. Select-
ꢀ
ed bond lengths [Š], angles, and torsion angles [8]: Mo1 P1 2.5079(4),
ꢀ
ꢀ
ꢀ
ꢀ
Mo1 P2 2.4917(4), P1 N1 1.7144(13), P1 N2 1.6726(13), P2 C2
ꢀ
ꢀ
ꢀ
ꢀ
1.8538(15), P2 C3 1.8317(16), C1 N1 1.474(2), C4 N2 1.4760(19), C5
ꢀ
ꢀ
ꢀ
ꢀ
N1 1.470(2), C6 N2 1.4701(19), C1 C2 1.535(2), C2 C3 1.526(2), C3 C4
1.525(2); P1-Mo1-P2 76.240(13), P1-Mo1-C20 98.26(5), P1-Mo1-C21
92.30(4), P1-Mo1-C22 95.44(5), P2-Mo1-C19 91.82(5), P2-Mo1-C21
92.12(5), P2-Mo1-C22 99.07(5), Mo1-P1-N1 115.26(5), Mo1-P1-N2
114.10(5), Mo1-P1-C7 118.07(5), Mo1-P2-C13 125.31(5), N1-P1-N2
101.81(7), C2-P2-C3 48.90(7), P1-N1-C1 114.99(10), P1-N2-C4 121.49(10),
P1-N1-C5 117.16(11), P1-N2-C6 121.21(11), P2-C2-C3 64.79(8), P2-C3-C2
66.30(8), P2-C2-C1 124.47(11), P2-C3-C4 118.81(11), N1-C1-C2
118.48(13), N2-C4-C3 117.41(13), P1-N1-C1-C2 43.94(18), P1-N2-C4-C3
39.03(18), N1-C1-C2-C3 ꢀ72.6(2), C2-C3-C4-N2 21.1(2), C1-C2-C3-P2
116.27(14), P2-C2-C3-C4 ꢀ110.09(15).
Scheme 5. Synthesis of complex 13.
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4335

K. Lammertsma et al.
for the five-membered chelate [(dppe)Mo(CO)4](dppe =
1,2-bis(diphenylphosphino)ethane).[15] The Mo1 P1 and
ꢀ
ꢀ
Mo1 P2 bond lengths of 2.5079(4) and 2.4917(4) Š, respec-
tively, are in the normal range.[1,16] The steric congestion
caused by the methyl group at N1 is also reflected in the
ꢀ
seven-membered
ring,
where
the
P1 N1
bond
ꢀ
(1.7144(13) Š) is slightly longer than the P1 N2 bond
(1.6726(13) Š) and the bond angles around N1 are smaller
(P1-N1-C1 114.99(10)8 and P1-N1-C5 117.16(11)8 versus P1-
N2-C4 121.49(10)8 and P1-N2-C6 121.21(11)8). While the ni-
trogen centers of the molecules in the crystal are chiral, the
whole crystal is racemic (centrosymmetric space group); pyr-
amidal inversion of the nitrogen atoms is rapid in solution.
Figure 2. Structure of 20 (displacement ellipsoid plot drawn at the 50%
probability level). Selected bond lengths [Š], angles, and torsion angles
Diphos basket 20: Phosphonite 7 was synthesized in a single
step (75%) by condensing cis-but-2-ene-1,4-diol with di-
chlorophenylphosphane in the presence of triethylamine as
base. Purification by distillation reduced the yield drastical-
ly.[17] Synthesis of 7 in a manner analogous to 5 is not a
viable alternative as the sluggish RCM occurs in poor
yield.[12] Reaction of 7 with cis-[Mo(CO)4(piperidine)2]and
3,4-dimethyl-1-phenylphosphole afforded 14 (30%), and the
subsequent Diels–Alder reaction with dimethylacetylene di-
carboxylate gave 17 (69%). Thermal decomposition at 808C
in toluene gave the desired and very stable diphosphane
basket 20 in reasonable yield (61%) as colorless crystals
(m.p. 169–1708C). As for 19, ring closure causes essentially
no deshielding (0.9 ppm) of the 31P NMR signal for the
ꢀ
ꢀ
ꢀ
ꢀ
[8]: Mo1 P1 2.4624(4), Mo1 P2 2.4606(4), P1 O1 1.6122(11), P1 O2
ꢀ
ꢀ
ꢀ
ꢀ
1.6229(10), P2 C2 1.8309(15), P2 C3 1.8330(15), C1 O1 1.4457(18), C4
ꢀ
ꢀ
ꢀ
O2 1.4399(18), C1 C2 1.512(2), C2 C3 1.525(2), C3 C4 1.512(2); P1-
Mo1-P2 77.626(12), P1-Mo1-C18 94.75(4), P1-Mo1-C19 85.92(4), P1-
Mo1-C20 95.76(4), P2-Mo1-C17 96.32(5), P2-Mo1-C19 86.94(4), P2-Mo1-
C20 93.38(4), Mo1-P1-O1 119.42(4), Mo1-P1-O2 110.58(4), Mo1-P1-C5
123.14(5), Mo1-P2-C11 129.20(5), O1-P1-O2 101.77(6), C2-P2-C3
49.20(7), P1-O1-C1 122.99(9), P1-O2-C4 119.99(9), P2-C2-C3 65.47(8),
P2-C3-C2 65.32(8), P2-C2-C1 119.59(11), P2-C3-C4 125.06(11), O1-C1-C2
115.76(13), O2-C4-C3 118.32(12), P1-O1-C1-C2 ꢀ40.05(19), P1-O2-C4-
C3 ꢀ30.58(19), O1-C1-C2-C3 ꢀ18.7(2), C2-C3-C4-O2 61.4(2), C1-C2-C3-
P2 110.41(15), P2-C2-C3-C4 ꢀ116.67(15).
molecular addition of the [Mo(CO)4L]phosphinidene com-
plex to the double bond of the seven-membered ring ligand
L (L=2,3,6,7-tetrahydro-1H-phosphepine (5), 1,3-dimethyl-
2,3,4,7-tetrahydro-1H-1,3,2-diazophosphepine (6), and 4,7-
dihydro-1,3,2-dioxaphosphepine (7)) Complex 18 and the di-
oxygen-containing 20 are very stable on heating, as opposed
to the nitrogen homologue 19, which may explain its lower
yield of formation. The 31P NMR resonances for the phos-
phirane ring are at similar high field (ca. d=ꢀ150 ppm) for
2
seven-membered ring (20: d=140.0 ppm), but the JP, P cou-
pling constant (20: 66.8 Hz) increases more (34.2 Hz). The
NMR spectroscopic data provide little additional insight in
this case as well.
A single-crystal X-ray structure determination of 20
(Figure 2) shows the same features as for 19, except that the
octahedral conformation around Mo is less distorted, as re-
flected in the smaller cis-P-Mo-C bond angles. The P1-Mo1-
P2 bond angle of 77.626(12)8 is similar in magnitude to that
2
all three complexes, but the already large JP, P coupling con-
stants increase from 38.1 to 58.7 to 66.8 Hz for 18, 19, and
20, respectively. The crystal structures of 19 and 20 show
small P-Mo-P bite angles of 76.240(13)8 and 77.626(12)8, re-
spectively. The new compounds are strong chelating com-
plexes: the transition-metal group cannot be liberated from
the ligand by either heating with sulfur,[19] oxidation by
iodine followed by ligand exchange,[20] or ligand displace-
ment with bis(diphenylphosphanyl)ethane.[10]
ꢀ
of 19. The two P Mo distances of 20 (2.4624(4) and
2.4606(4) Š) are virtually identical and are about 0.04 Š
shorter than those of 1, 2, 19, and other Mo(CO)n-com-
plexed phosphiranes,[1,16] but similar to those of
[RO(R’)2PMo(CO)5](2.436 Š) and [(RO) 3PMo(CO)5]
(2.485 Š);[18] we are not aware of structural data for molyb-
denum
phosphonite
complexes
such
as
ꢀ
[(OC)5MoP(OR)2R’]. The P O bonds (1.6122(11) and
1.6229(10) Š) are slightly longer than usual.[18]
Experimental Section
Conclusion
All experiments were performed under an atmosphere of dry nitrogen.
Solids were dried in vacuo and liquids were distilled under N2 prior to
use. Toluene was distilled over sodium and THF was dried by successive
distillation over LiAlH4 and sodium/benzophenone. Diethyl ether was
distilled over LiAlH4. CH2Cl2 was dried over P2O5. cis-[Mo-
(CO)4(piperidine)2][9] and 3,4-dimethyl-1-phenylphosphole[21] were pre-
pared according to literature procedures. NMR spectra were recorded
with a Bruker WM 250 spectrometer (1H, 13C) and internally referenced
to residual solvent resonances or 85% H3PO4 (31P) as external standard.
IR spectra were recorded with a Mattson 6030 Galaxy FT-IR spectropho-
The synthesis of the novel Mo complexes 18–20 expands the
access to a new class of unsymmetrical diphos chelates in
ꢀ
which the chains (C-C-X versus C C) connecting the phos-
phorus atoms and the substitution pattern (X=CH2, NCH3,
O) around one of them can be varied, particularly to a small
number of O- and N-containing diphos chelates. The novel
“baskets” were obtained by metal-template-directed intra-
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Chem. Eur. J. 2006, 12, 4333 – 4340

Bidentate Phosphorus Baskets
FULL PAPER
tometer and high-resolution mass spectra (HR-MS) with a Finnigan Mat
900 spectrometer. Melting points were measured for samples in unsealed
capillaries and are uncorrected.
128.5 (d, 2JP, C =13.1 Hz; o-Ph), 131.3 (d, 1JP, C =154.4 Hz; ipso-Ph), 131.5
(d, 4JP, C =2.8 Hz; p-Ph), 132.2 (d, 3JP, C =8.7 Hz; m-Ph), 134.9 ppm (d,
3JP, C =5.1 Hz; CH=); 31P NMR (CDCl3): d=30.0 ppm (s); HR-MS calcd
for C14H21N2OP: 264.1391; found 264.13998 (d 6”10ꢀ3).
Synthesis of cis-tetracarbonyl(3,4-dimethyl-1-phenyl-1H-phosphole)(1-
phenyl-2,3,6,7-tetrahydro-1H-phosphepine)molybdenum (12)
Synthesis of 1,3-dimethyl-2-phenyl-1,3,4,7-tetrahydro-[1,3,2]diazaphosphe-
pine 2-oxide (22) by ring-closing metathesis of 21: Phosphane 21 (500 mg,
1.9 mmol) was dissolved in dichloromethane (100 mL), catalyst 11
(47 mg, 0.06 mmol) was added, and the purple solution was heated at
reflux for 3 h. After evaporation of solvent and column chromatography
(silica gel; ethyl acetate/methanol, 95:5), 22 (350 mg, 78%) was isolated
as a colorless oil.
Synthesis of 1-phenyl-2,3,6,7-tetrahydro-1H-phosphepine 1-oxide (10):
Grubbsꢁ catalyst 11 (6 mol%) was added in three equal portions to a sol-
ution of diene 9 (2.5 g, 10.7 mmol) in dichloromethane (0.02m). The reac-
tion mixture was heated at reflux until full conversion of the starting ma-
terial, as shown by 31P NMR spectroscopy. The solvent was then evapo-
rated and product 10 purified by column chromatography (silica gel,
ethyl acetate/ethanol, 10:1) to yield a colorless solid (955 mg, 44%). A
publication by Gouverneur et al. reports 89% isolated yield,[7] although
product characterization was not included.
1H NMR (CDCl3): d=2.69 (d, 3JP, H =9.5 Hz, 6H; NCH3), 3.44–3.57 (m,
2H; CH2N), 3.71–3.85 (m, 2H; CH2N), 5.68 (t, 3JH,H =2.4 Hz, 2H; =
CH2), 7.44–7.49 (m, 3H; Ar), 7.78–7.85 ppm (m, 2H; Ar); 13C NMR
(CDCl3): d=36.1 (d, 2JP,C =4.4 Hz; CH3), 48.0 (d, 2JP,C =2.8 Hz; CH2),
1
M.p. 75–768C; H NMR (CDCl3): d=1.85–2.09 (m, 4H; PCH2), 2.15–2.40
2
1
127.6 (s; CH=), 128.6 (d, JP, C =13.3 Hz; o-Ph), 130.2 (d, JP,C =159.9 Hz;
ipso-Ph), 131.7 (d, 4JP, C =2.8 Hz; p-Ph), 132.5 ppm (d, 3JP, C =8.8 Hz; m-
Ph); 31P NMR (CDCl3): d=32.3 ppm (s); HR-MS calcd for C12H27N2OP:
236.1078; found 236.10786 (d 4”10ꢀ4).
(m, 2H; CH2C=), 2.80–2.91 (m, 2H; CH2C=), 7.46–7.51 (m, 3H; Ar),
2
7.69–7.77 ppm (m, 2H; Ar); 13C NMR (CDCl3): d=19.4 (d, JP,C =5.0 Hz;
CH2), 29.3 (d, 1JP, C =66.0 Hz; CH2-P), 128.8 (d, 2JP, C =11.2 Hz; o-Ph),
130.1 (d, 3JP, C =9.0 Hz; m-Ph), 131.8 (d, 4JP,C =2.7 Hz; p-Ph), 132.4 (s, =
CH phosphepine), 134.1 ppm (d, 1JP, C =94.5 Hz; ipso-Ph); 31P NMR
(CDCl3): d=41.7 ppm (s); HR-MS calcd for C12H15OP: 206.0861; found
206.08671 (d 2”10ꢀ3).
Synthesis of N,N’-diallyl-N,N’-dimethyl-P-phenyl phosphonous diamide
(23): PhPCl2 (0.712 mL, 5.2 mmol) was dissolved in dry diethyl ether
(25 mL) and cooled to ꢀ788C. A mixture of allylmethylamine (1.00 mL,
10.5 mmol) and triethylamine (1.5 mL, 10.5 mmol) was then added slowly
from a dropping funnel. The reaction mixture was slowly warmed up to
room temperature and the salts were filtered off. Evaporation of the sol-
vent yielded diaminophosphane 23 (1.23 g; 95%) of sufficient purity for
further use. 1H NMR (CDCl3): d=2.61 (d, 3JP,H =6.5 Hz, 6H; NCH3),
3.63–3.69 (m, 4H; CH2N), 5.13–5.23 (m, 4H; =CH2), 5.80–5.91 (m, 2H;
CH), 7.28–7.45 ppm (m, 5H; Ar); 31P NMR (CDCl3): d=102.3 ppm (s).
Reduction of 10 to phosphane 5: 1-Phenyl-2,3,6,7-tetrahydro-1H-phos-
phepine 1-oxide (10; 500 mg, 2.43 mmol) was dissolved in phenylsilane
(2.4 mL) and the mixture was heated for 4 h at 808C. Excess phenylsilane
was evaporated off under reduced pressure and the resulting oil was ex-
tracted with hexane (2”10 mL). Product 5 is very sensitive towards
oxygen and was used without further purification. 31P NMR (hexane):
d=ꢀ13.5 ppm (s).
Synthesis of (N,N’-diallyl-N,N’-dimethyl-P-phenyl phosphonous diamide)-
Synthesis of 12:
A mixture of cis-[Mo(CO)4(piperidine)2](0.925 g,
pentacarbonylmolybdenum (24): a) A solution containing [Mo(CO)5-
2.42 mmol) and 3,4-dimethyl-1-phenylphosphole (0.462 g, 2.42 mmol) was
stirred in refluxing dichloromethane (20 mL) for 10 min. 1-Phenyl-
2,3,6,7-tetrahydro-1H-phosphepine was then added and the mixture was
stirred at reflux for an additional 2 h. Evaporation to dryness and column
chromatography (silica gel; pentane/dichloromethane, 4:1) afforded 12
(600 mg, 41%) as a yellow solid. Recrystallization from dichlorome-
thane/hexane gave yellow crystals. M.p. 104–1058C; 1H NMR (CDCl3):
d=2.02 (s, 6H; CH3), 2.14–2.38 (m, 8H; CH2 & CH2P), 5.74 (m, 2H;
phosphepine-CH), 6.15 (d, 2JP, H =36.0 Hz, 2H; phosphole-CH), 7.26–
7.36 ppm (m, 10H; Ar); 13C NMR (CDCl3): d=17.7 (d, 3JP, C =9.9 Hz;
CH3), 23.4 (d, 2JP, C =4.5 Hz; CH2), 28.9 (dd, 1JP, C =18.4, 3JP,C =2.0 Hz;
CH2P), 128.6–131.3 (m, Ar), 131.1 (dd, 1JP,C =35.4, 3JP, C =1.8 Hz; PCH),
131.6 (s; CH2C=), 133.5 (dd, 3JP,C =1.7, 1JP, C =16.0 Hz; phosphole ipso-
[22]
A
from
[Mo(CO)6](1.32 g, 5 mmol). A solution containing phosphane 23 (1.27 g,
5.0 mmol) in hexane (10 mL) was then slowly added. 31P NMR spectro-
scopy showed the formation of several unidentified products. Column
chromatography (silica gel, hexane) afforded complex 24 (470 mg,
0.97 mmol; 20% yield) as a thick oil.
b) A solution containing [Mo(CO)6](4.84 g, 18.5 mmol) and phosphane
23 (3.67 g, 14.8 mmol) was heated at 1008C in methylcyclohexane
(100 mL) for 3 h. 31P NMR spectroscopy showed the formation of several
products, most of which were identical to those obtained by method a).
After the mixture had been cooled to room temperature, the unreacted
[Mo(CO)6]was filtered off and the remaining yellow solution was evapo-
rated under reduced pressure. Column chromatography (silica gel, pen-
tane) afforded the complexed phosphane 24 (2.15 g; 30%) as a thick oil,
Ph), 139.0 (dd, 3JP,C =1.6, 1JP, C =27.2 Hz; phosphepine ipso-Ph), 149.0 (d,
2
2JP, C =7.8 Hz; CHCCH3), 210.1 (t, 2JP, C =9.2 Hz; COax), 215.2 (dd, JP, C
=
1
which solidified in the freezer. M.p. 31–328C; H NMR (CDCl3): d=2.72
8.2, 2JP, C =16.0 Hz; COeq), 215.5 ppm (dd, 2JP,C =8.7, 2JP,C =21.3 Hz;
COeq); 31P NMR (CDCl3): d=26.1 (d, 2JP, P =24.0 Hz; phosphepine),
32.7 ppm (d, 2JP, P =24.0 Hz; phosphole); HR-MS calcd for
C28H28MoO4P2: 588.0518; found 588.04955 (d 2”10ꢀ3); IR (CH2Cl2): n˜ =
2017 (m) (n(CO)), 1907 (s) (n(CO)), 1871 cmꢀ1 (sh) (n(CO)).
(d, 3JP, H =10.0 Hz, 6H; CH3), 3.70–3.91 (m, 4H; CH2N), 5.23–5.31 (m,
4H; =CH2), 5.73–5.86 (m, 2H; CH), 7.26–7.60 ppm (m, 5H; Ar);
2
13C NMR (CDCl3): d=37.7 (d, 2JP, C =1.8 Hz; CH3), 56.7 (d, JP, C =8.5 Hz;
CH2N), 118.2 (s; =CH2), 129.2–130.8 (m; Ar), 135.8 (d, 3JP, C =6.5 Hz;
2
CH), 141.7 (d, 1JP, C =61.7 Hz; phosphepine ipso-Ph), 205.7 (d, JP,C
=
Synthesis of tetracarbonyl(3,4-dimethyl-1-phenyl-1H-phosphole)(1,3-di-
methyl-2-phenyl-2,3,4,7-tetrahydro-1H-[1,3,2]diazaphosphepine)molybde-
num (13)
9.8 Hz; COax), 211.4 ppm (d, 2JP, C =27.6 Hz; COeq); 31P NMR (CDCl3):
d=126.0 ppm (s); HR-MS calcd for C19H21MoN2O5P: 486.0242; found
486.02322 (d 1”10ꢀ3); IR (CH2Cl2): n˜ =2071 (m) (n(CO)), 1943 cmꢀ1 (s)
(n(CO)).
Synthesis of N,N’-diallyl-N,N’-dimethyl-P-phenylphosphonic diamide (21):
A solution of PhP(O)Cl2 (975 mg, 5.0 mmol) and Et3N (1.01 g, 10 mmol)
in dichloromethane (25 mL) was slowly added to a stirred solution of
methylallylamine (710 mg, 10 mmol) containing a catalytic amount of
DMAP (31 mg, 0.05 mmol) in dichloromethane (50 mL) at 08C. After
2 h, the solvent was evaporated and diethyl ether (50 mL) was added to
yield a yellow solution and pale yellow salts. The solution was filtered
and the salts washed with diethyl ether (10 mL). Evaporation and
column chromatography (silica gel; ethyl acetate/MeOH, 95:5) yielded
21 (890 mg, 67%) as a colorless oil.
1H NMR (CDCl3): d=2.58 (d, 3JP, H =10.0 Hz, 6H; NCH3), 3.57 (m, 4H;
CH2N), 5.10–5.19 (m, 4H; =CH2), 5.63–5.77 (m, 2H; CH), 7.43–7.47 (m,
3H; Ar), 7.73–7.81 ppm (m, 2H; Ar); 13C NMR (CDCl3): d=33.1 (d,
2JP, C =3.5 Hz; NCH3), 51.5 (d, 2JP, C =4.2 Hz; NCH2), 117.6 (s; =CH2),
Synthesis
of
pentacarbonyl(1,3-dimethyl-2-phenyl-1,3,4,7-tetrahydro-
[1,3,2]diazaphosphepine)molybdenum (25) by ring-closing metathesis of
24: Complex 24 (470 mg, 0.97 mmol) was dissolved in dichloromethane
(25 mL). RCM-catalyst 11 (2 mol%; 16 mg, 0.02 mmol) was added and
the mixture was heated at reflux temperature for 10 min. After evapora-
tion of the solvent and column chromatography (silica gel, n-hexane),
complex 25 (430 mg, 97%) was isolated as a white solid. M.p. 136–1378C
1
3
(decomp); H NMR (CDCl3): d=3.07 (d, JP, H =14.5 Hz, 6H; CH3), 3.13–
3.27 (m, 2H; CH2N), 4.26–4.35 (m, 2H; CH2N), 6.10–6.15 (m, 2H; CH),
2
7.36–7.68 ppm (m, 5H; Ar); 13C NMR (CDCl3): d=41.1 (d, JP,C
=
2
14.34 Hz; CH3), 48.8 (d, JP, C =7.2 Hz; CH2N), 129.5–130.6 (m, Ar), 135.1
(s, CH), 141.8 (d, 1JP, C =63.7 Hz; ipso-Ph), 205.8 (d, 2JP, C =9.9 Hz; COax),
211.5 ppm (d, 2JP, C =27.1 Hz; COeq); 31P NMR (CDCl3): d=135.1 ppm
Chem. Eur. J. 2006, 12, 4333 – 4340
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
4337

K. Lammertsma et al.
(s); HR-MS calcd for C17H27MoN2O5P: 457.9929; found 457.99393 (d 1”
10ꢀ3); IR(CH2Cl2): n˜ =2072 (w) (n(CO)), 1944 cmꢀ1 (s) (n(CO)).
592.00659 (d 1”10ꢀ3); IR (CH2Cl2): n˜ =2025 (m) (n(CO)), 1913 cmꢀ1 (s)
(n(CO)).
ACHTREUNG
Synthesis
phosphabicyclo
of
cis-tetracarbonyl(dimethyl
5,6-dimethyl-7-phenyl-7-
Synthesis of 13 by irradiation of 25 in the presence of phenylphosphole:
A solution of complex 25 (1.55 g, 3.4 mmol) and 3,4-dimethyl-1-phenyl-
phosphole (637 mg, 3.4 mmol) in THF (100 mL) was prepared. This mix-
ture was irradiated for 5 h with light from a high-pressure Philips Hg
lamp (0.9 A, Type 93110E), while N2 was bubbled through the solution at
a slow rate. Evaporation of THF and subsequent column chromatography
starting with pentane and gradually changing to pentane/dichlorome-
thane (4:1) resulted in the isolation of complex 13 (580 mg, 28%) as a
yellow solid. Furthermore, compound 25 (700 mg, 45%) was recovered
and could be re-used. The yields are calculated based on the amount of
starting material used (3.4 mmol) and are not corrected for recovery of
25. Recrystallization of 13 from DCM/hexane gave yellow crystals. M.p.
142–1438C; 1H NMR (CDCl3): d=2.07 (s, 6H; phosphole-CH3), 2.92 (d,
3JP, H =14.1 Hz, 6H; NCH3), 3.11–3.25 (m, 2H; CH2N), 4.14–4.23 (m, 2H;
CH2N), 6.00 (m, 2H; phosphepine HC=), 6.40 (d, 2JP, H =35.3 Hz, 2H;
AHCTREUNG
tetrahydro-1H-phosphepine)molybdenum (15): A mixture of complex 12
(0.500 g, 0.85 mmol) and dimethylacetylene dicarboxylate (2.5 mL,
20 mmol) was stirred at 508C for 22 h. Column chromatography over
silica gel, starting with pentane as eluent and gradually changing to di-
chloromethane, gave recovered dimethylacetylene dicarboxylate first, fol-
lowed by compound 15 (390 mg, 63%) as a yellow oil. Crystallization
from dichloromethane/hexane gave yellow crystals. M.p. 131–1328C;
1H NMR (CDCl3): d=1.88 (d, 4JP, H =0.9 Hz, 6H; CH3), 2.19–2.35 (m,
8H; CH2-P & CH2), 3.39 (d, 2JP, H =2.9 Hz, 2H; phosphanorbornadiene-
CH), 3.61 (s, 6H; OCH3), 5.73 (m, 2H; =CH), 7.26–7.49 ppm (m, 10H;
Ar); 13C NMR (CDCl3): d=16.2 (d, 3JP, C =1.8 Hz; CH3), 23.3 (d, JP,C
=
2
5.2 Hz; CH2C=), 29.2 (dd, 3JP, C =1.8, 1JP, C =19.9 Hz; CH2P), 52.4 (s,
OCH3), 60.0 (dd, 3JP, C =2.0, 1JP, C =14.3 Hz; phosphonorbornadiene-CH),
128.1–130.4 (m; Ar), 131.7 (s; =CH), 137.7 (d, 1JP,C =17.4 Hz; phospha-
phosphole HC=), 7.26–7.60 ppm (m, 10H; Ar); 13C NMR (CDCl3): d=
3
1
2
17.6 (d, 3JP,C =10.1 Hz; phosphole-CH3), 40.0 (dd, 4JP,C =2.0, JP,C
=
norbornadiene ipso-Ph), 139.3 (dd, JP,C =2.4, JP, C =27.4 Hz; phosphepine
ipso-Ph), 142.3 (d, 2JP,C =3.0 Hz; CHCCH3), 146.2 (d, 2JP, C =3.5 Hz;
2
15.0 Hz; NCH3), 49.0 (d, JP, C =6.8 Hz; CH2N), 128.7–131.6 (m, Ar), 131.3
(dd, 3JP, C =11.6, 1JP, C =46.7 Hz; phosphole-CH), 133.4 (d, 1JP,C =32.2 Hz;
phosphole ipso-Ph), 134.6 (s; phosphepine-CH), 141.7 (d, 1JP, C =55.7 Hz;
CCO2CH3), 165.6 (d, 3JP, C =2.3 Hz; CO2CH3), 209.3 (dd, 2JP, C =8.0, JP,C
=
2
9.8 Hz; COax), 214.8 (dd, 2JP, C =8.8, 2JP,C =12.4 Hz; COeq), 215.3 ppm (dd,
2JP, C =5.7, 2JP, C =8.8 Hz; COeq); 31P NMR (CDCl3): d=25.7 (d, JP, P
=
2
phosphepine ipso-Ph), 148.7 (d, 2JP, C =8.11 Hz; P CH=C), 209.3 (dd,
ꢀ
26.1 Hz; phosphepine), 251.9 ppm (d, 2JP, P =26.1 Hz; phosphanorborna-
diene-P); IR (CH2Cl2): n˜ =2021 (m) (n(CO)), 1915 (s) (n(CO)),
1890 cmꢀ1 (sh) (n(CO)). Compound 15 was too unstable for HR-MS; for-
mation of 18 was observed.
2JP, C =8.5, 2JP, C =10.3 Hz; COax), 215.0 (dd, 2JP, C =9.8, 2JP, C =21.1 Hz;
COeq), 216.2 ppm (dd, 2JP,C =8.6, 2JP,C =30.4 Hz; COeq); 31P NMR
2
(CDCl3): d=32.3 (d, 2JP, P =25.5 Hz; phosphole), 138.2 ppm (d, JP, P
=
25.5 Hz; phosphepine); HR-MS calcd for C28H30MoN2O4P2: 618.0735;
found 618.07009 (d 2”10ꢀ3); IR
(CH2Cl2): n˜ =2022 (m) (n(CO)), 1908 (s)
(n(CO)), 1875 cmꢀ1 (sh) (n(CO)).
Synthesis of tetracarbonyl(3,4-dimethyl-1-phenyl-1H-phosphole)(2-
A
Synthesis
phosphabicyclo
of
cis-tetracarbonyl(dimethyl
5,6-dimethyl-7-phenyl-7-
AHCTREUNG
phenyl-2,3,4,7-tetrahydro-1H-[1,3,2]diazaphosphepine)molybdenum (16):
A solution of complex 13 (500 mg, 0.81 mmol) and dimethylacetylene di-
carboxylate (3 mL; 24 mmol) in dichloromethane (1 mL) was heated for
28 h at 458C. Column chromatography, starting with hexane and gradual-
ly changing to dichloromethane as eluent, afforded complex 16 (330 mg;
55%) as an orange solid. Recrystallization (CH2Cl2/hexane) resulted in
the formation of orange needles. M.p. 71–728C; 1H NMR (CDCl3): d=
1.96 (d, 4JP,H =1.0 Hz, 6H; CH3), 2.96 (d, 3JP, H =14.1 Hz, 6H; NCH3),
3.13–3.20 (m, 2H; CH2N), 3.59 (s, 2H; phosphanorbornadiene-CH), 3.61
phenyl-4,7-dihydro-[1,3,2]dioxaphosphepine)molybdenum (14)
Synthesis of 2-phenyl-4,7-dihydro-1,3,2-dioxaphosphepine (7): PhPCl2
(3.58 g, 20.0 mmol) in 50 mL of diethyl ether was slowly added to a solu-
tion of triethylamine (4.55 g, 40.0 mmol) and cis-but-2-ene-1,4-diol
(1.84 g, 20.0 mmol) in 150 mL of diethyl ether at 08C and stirred for 1 h
before warming to room temperature. 31P NMR spectroscopy showed an
excellent conversion to the desired product. After filtration of the salts
and evaporation of solvent, 3.00 g of 7 (>90% pure by 31P NMR) was
obtained as a colorless oil, which could be used without further purifica-
tion. A minor side product (<10% by 31P NMR) at d=21.6 ppm was ob-
served. During distillation, a gummy material was formed that reduced
the yield dramatically. After distillation at 808C/2”10ꢀ4 mbar, 7 (830 mg;
24%) was obtained as an air-sensitive colorless oil.
(s, 6H; OCH3), 4.16–4.20 (m, 2H; CH2N), 6.00 (m, 2H; phosphepine-
CH), 7.04–7.49 ppm (m, 10H; Ar); 13C NMR (CDCl3): d=16.2 (d, JP, C
=
3
2.1 Hz; CH3), 40.0 (d, 2JP, C =14.1 Hz; NCH3), 49.0 (d, 2JP, C =6.9 Hz;
CH2N), 52.3 (s, OCH3), 60.5 (dd, 3JP,C =1.4, 1JP,C =14.2 Hz; phosphonor-
1
bornadiene-CH), 127.9–131.2 (m; Ar), 134.7 (s; =CH), 138.1 (d, JP,C
=
17.4 Hz; phosphanorbornadiene ipso-Ph), 141.7 (dd, 3JP,C =1.5, JP,C
=
1
2
1H NMR (CDCl3): d=4.45–4.66 (m, 4H; CH2), 5.75 (t, H,H =1.9 Hz, 2H;
57.0 Hz; phosphepine ipso-Ph), 141.9 (d, 2JP, C =2.8 Hz; CHCCH3), 146.7
CH2CH), 7.44–7.48 (m; 3H; Ar), 7.68–7.74 ppm (m; 2H; Ar); 13C NMR
2
3
(d, JP,C =3.6 Hz; CCO2CH3), 165.7 (d, JP, C =2.1 Hz; CO2CH3), 208.9 (dd,
2JP, C =8.2, 2JP, C =10.5 Hz; COax), 215.0 (dd, 2JP, C =10.8, 2JP, C =28.9 Hz;
COeq), 215.8 ppm (dd, 2JP,C =10.0, 2JP,C =28.2 Hz; COeq); 31P NMR
(CDCl3): d=250.5 (d, 2JP, P =26.6 Hz; 7-phosphanorbornadiene),
137.6 ppm (d, 2JP, P =26.6 Hz; phosphepine); IR (CH2Cl2): n˜ =2024 (m)
(n(CO)), 1918 (s) (n(CO)), 1889 cmꢀ1 (sh) (n(CO)). Compound 16 was
too unstable for HR-MS; formation of compound 19 was observed.
4
3
(CDCl3): d=64.0 (s; CH2), 128.2 (d, JP, C =4.9 Hz; m-Ph), 129.6 (d, JP, C
=
20.6 Hz; o-Ph), 130.0 (s; phosphepine HC=), 131.3 (s; p-Ph), 140.8 ppm
1
(d, JP, C =32.0 Hz; ipso-Ph); 31P NMR (CDCl3): d=161.1 ppm (s).
Synthesis of 14:
A mixture of cis-[Mo(CO)4(piperidine)2](2.1 g,
5.6 mmol) and 2-phenyl-4,7-dihydro-1,3,2-dioxaphosphepine (7; 1.1 g,
5.6 mmol) was stirred in refluxing dichloromethane (20 mL) for 10 min.
3,4-Dimethyl-1-phenylphosphole (1.0 g, 5.6 mmol) in dichloromethane
(10 mL) was added and the mixture was stirred at reflux for an additional
3 h. Evaporation to dryness and column chromatography (silica gel; pen-
tane/dichloromethane, 4:1) gave complex 14 (0.841 g; 30%) as a yellow
solid. Recrystallization from diethyl ether/hexane afforded yellow crys-
tals. M.p. 111–1128C; 1H NMR (CDCl3): d=2.05 (s, 6H; CH3), 4.41–4.62
(m, 4H; CH2), 5.70 (s, 2H; CH, phosphepine), 6.41 (d, 2JP, H =36.3 Hz,
2H; CH phosphole), 7.29–7.54 ppm (m, 10H; Ar); 13C NMR (CDCl3):
Synthesis
phosphabicyclo
of
cis-tetracarbonyl(dimethyl
5,6-dimethyl-7-phenyl-7-
AHCTREUNG
hydro-[1,3,2]dioxaphosphepine)molybdenum (17): A mixture of complex
14 (0.72 g, 1.2 mmol) and dimethylacetylene dicarboxylate (2.5 mL,
20 mmol) was stirred at 458C for 22 h. Column chromatography over
silica gel, starting with pentane as eluent and gradually changing to di-
chloromethane, gave dimethylacetylene dicarboxylate first, followed by
complex 17 (0.61 g; 69%) as a yellow oil. Crystallization from dichloro-
methane/hexane gave yellow crystals. M.p. 139–1408C; 1H NMR
(CDCl3): d=1.97 (d, 4JP, H =0.8 Hz, 6H; CH3), 3.63 (s, 6H; OCH3), 3.77
(d, 2JP, H =2.6 Hz, 2H; phosphanorbornadiene-CH), 4.45–4.56 (m, 4H;
3
d=17.7 (d, JP,C =10.3 Hz; CH3), 64.6 (d, 2JP, C =6.0 Hz; CH2), 128.5–131.5
1
(m; Ph), 129.4 (s; phosphepine HC=), 131.2 (d, JP, C =35.0 Hz; phosphole
1
HC=), 133.8 (d, 1JP, C =33.0 Hz; phosphole ipso-Ph), 141.2 (d, JP,C
=
33.8 Hz; phosphepine ipso-Ph), 148.9 (d, 2JP, C =8.2 Hz; CHCCH3), 209.0
CH2), 5.75 (s, 2H; =CH), 7.09–7.59 ppm (m, 10H; Ar); 13C NMR
2
2
2
2
(CDCl3): d=16.3 (d, 3JP, C =1.8 Hz; CH3), 52.4 (s, OCH3), 60.4 (dd, JP, C
=
3
(dd, JP, C =8.8, JP, C =12.1 Hz; COax), 213.7 (dd, JP, C =11.5, JP,C =19.4 Hz;
COeq), 214.0 ppm (dd, 2JP,C =8.2, 2JP,C =36.6 Hz; COeq); 31P NMR
2.0, 1JP, C =15.4 Hz; phosphonorbornadiene-CH), 64.8 (d, 2JP,C =6.1 Hz;
OCH2), 128.1–129.5 (m; Ar), 131.0 (s; =CH), 138.0 (d, 1JP,C =17.4 Hz;
phosphanorbornadiene ipso-Ph), 141.3 (d, 1JP, C =34.9 Hz; phosphepine
(CDCl3): d=33.0 (d, 2JP, P =29.0 Hz; phosphole-P), 190.9 ppm (d, JP, P
=
2
29.0 Hz; O-P); HR-MS calcd for C26H24MoO6P2: 592.0103; found
4338
www.chemeurj.org
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2006, 12, 4333 – 4340

Bidentate Phosphorus Baskets
FULL PAPER
ipso-Ph), 142.4 (d, 2JP,C =4.6 Hz; CHCCH3), 146.4 (d, 2JP, C =3.7 Hz;
X-ray crystal structure determinations: X-ray intensities were measured
with a Nonius Kappa CCD diffractometer with rotating anode and
graphite monochromator (l=0.71073 Š) at a temperature of 150(2) K up
to a resolution of (sinq/l)max =0.65 Šꢀ1. The structures were solved with
automated Patterson methods[23] and refined with SHELXL-97[24] on F2
of all reflections. Non-hydrogen atoms were refined freely with aniso-
tropic displacement parameters. All hydrogen atoms were located in the
difference Fourier map. Methyl and phenyl H-atoms were refined with a
riding model; all other H-atoms were refined freely with isotropic dis-
placement parameters. Geometry calculations, drawings, and checking for
higher symmetry were performed with the PLATON package.[25]
2
CCO2CH3), 165.7 (d, 3JP, C =2.3 Hz; CO2CH3), 208.4 (dd, 2JP, C =8.3, JP,C
=
12.1 Hz; COax), 213.2 (dd, 2JP,C =11.2, 2JP,C =26.7 Hz; COeq), 213.9 ppm
(dd, 2JP, C =9.9, 2JP, C =33.7 Hz; COeq); 31P NMR (CDCl3): d=190.8 (d,
2JP, P =32.6 Hz; phosphepine), 248.8 ppm (d, 2JP, P =32.6 Hz; phosphanor-
bornadiene); HR-MS calcd for C32H30MoO10P2: 734.0369; found
734.03273 (d 2”10ꢀ2); IR (CH2Cl2): n(CO)=2029 (w) (n(CO)),
1923 cmꢀ1 (s) (n(CO)).
Synthesis
of
tetracarbonyl(4,8-diphenyl-4,8-diphospha-bicyclo-
ACHTREUNG
tion of 15 (0.35 g, 0.48 mmol) in toluene (5 mL) was stirred at 808C for
3 h. Evaporation to dryness, column chromatography (silica gel; dichloro-
methane/pentane, 2:1), and recrystallization from dichloromethane/
hexane gave 18 (0.160 g, 66%) as colorless crystals. M.p. 194–1958C
Crystal structure determination of 19: C22H22MoN2O4P2, Fw=536.30, col-
orless block, 0.42”0.36”0.18 mm3, orthorhombic, Pbca (no. 61), a=
16.48859(15), b=15.3260(9), c=18.2133(4) Š, V=4602.6(3) Š3, Z=8,
1calcd =1.548 gcmꢀ3; 110857 reflections were measured. An absorption
correction based on multiple measured reflections was applied (m=
0.74 mmꢀ1, 0.72–0.88 correction range); 5283 reflections were unique
(Rint =0.029); 306 parameters were refined with no restraints. R1/wR2
1
(decomp); H NMR: (CDCl3): d=2.07–2.38 (m, 6H; CH & CH2P), 2.43–
2.72 (m, 2H; CHCH2), 2.78–2.98 (m, 2H; CHCH2) , 7.37–7.60 ppm (m,
10H; Ar); 13C NMR: (CDCl3): d=21.9 (d, 2JP, C =3.4 Hz; CHCH2), 26.7
(dd, 1JP, C =20.5, 3JP, C =4.0 Hz; CH2P), 26.8 (dd, 3JP,C =4.8, 1JP, C =15.4 Hz;
3
1
[I>2s(I)]: 0.0200/0.0457. R1/wR2 (all refl.): 0.0287/0.0504. S=1.092. Re-
CHP), 128.9–131.4 (m; Ar), 135.8 (dd, JP, C =4.2, JP,C =11.8 Hz; phosphir-
ꢀ3
ane ipso-Ph), 138.5 (dd, 3JP, C =8.4, 1JP, C =30.2 Hz; phosphepane ipso-Ph),
sidual electron density between ꢀ0.29 and 0.47 eŠ
.
2
209.7 (dd, 2JP, C =9.5, 2JP,C =11.4 Hz; COax), 214.6 (dd, 2JP,C =9.2, JP,C
=
Crystal structure determination of 20: C20H16MoO6P2, Fw=510.21, color-
less block, 0.45”0.42”0.36 mm , triclinic, P1 (no. 2), a=7.5410(1), b=
3
31.3 Hz; COeq), 216.4 ppm (dd, 2JP, C =10.0, 2JP, C =22.3 Hz; COeq);
31P NMR: (CDCl3): d=ꢀ150.5 (d, 2JP, P =38.4 Hz; phosphirane),
16.46 ppm (d, 2JP, P =38.4 Hz; phosphepane); HR-MS calcd. for
¯
9.6907(1), c=14.8771(2) Š, a=96.2156(11)8, b=101.7812(10)8, g=
106.0581(10)8, V=1006.95(2) Š3, Z=2, 1calcd =1.683 gcmꢀ3; 16625 reflec-
tions were measured. An absorption correction based on multiple meas-
ured reflections was applied (m=0.85 mmꢀ1, 0.67–0.74 correction range);
4598 reflections were unique (Rint =0.016); 286 parameters were refined
with no restraints. R1/wR2 [I>2s(I)]: 0.0175/0.0416. R1/wR2 (all reflec-
C22H20MoO4P2: 507.9892; found 507.98926 (d 2”10ꢀ3); IR
(CH2Cl2): n˜ =
R
2019 (m) (n(CO)), 1901 (s) (n(CO)), 1884 cmꢀ1 (sh) (n(CO)); EI-MS: m/
z (%): 508 (18) [M+], 480 (2) [M+ꢀCO], 452 (24) [M+ꢀ2CO], 424 (15)
[M+ꢀ3CO], 396 (100) [M+ꢀ4CO].
tions): 0.0218/0.0428. S=1.065. Residual electron density between ꢀ0.27
Synthesis
diphosphabicyclo
of
tetracarbonyl(3,5-dimethyl-4,8-diphenyl-3,5-diaza-4,8-
[5.1.0]octane)molybdenum (19) by thermal decomposi-
ꢀ3
and 0.36 eŠ
.
ACHTREUNG
CCDC-291538 (19) and CCDC-291539 (20) contain the supplementary
crystallographic data for this paper. These data can be obtained free of
charge from The Cambridge Crystallographic Data Center via
www.ccdc.cam.ac.uk/data_request/cif.
tion of 16: A solution of 16 (146 mg, 0.19 mmol) in 3 mL of toluene was
stirred at 708C for 5 h. Evaporation to dryness, chromatography (silica
gel; dichloromethane/pentane, 2:1), and recrystallization from dichloro-
methane/hexane gave complex 19 (25 mg; 24%) as colorless crystals. A
second fraction contained starting material 16 (46 mg; 32%). M.p. 83–
848C; 1H NMR (CDCl3): d=2.32 (m, 2H; CH), 2.42 (d, 3JP, H =8.8 Hz,
6H; NCH3), 3.60–3.80 (m, 2H; CH2N), 4.02–4.11 (m, 2H; CH2N), 7.40–
7.69 ppm (m, 10H; Ar); 13C NMR (CDCl3): d=25.8 (dd, 1JP, C =14.0,
Acknowledgments
3JP, C =4.8 Hz; CH), 40.7 (d, 2JP, C =2.5 Hz; NCH3), 51.0 (dd, 2JP, C =7.4,
1
2JP, C =2.5 Hz; CH2N), 128.1–131.2 (m; Ar), 133.8 (dd, 3JP, C =7.7, JP,C
=
This work was supported by the Council for Chemical Sciences of the
Netherlands Organization for Scientific Research (NWO/CW).
9.6 Hz; phosphirane ipso-Ph), 136.3 (dd, 3JP, C =5.8, 1JP, C =43.7 Hz; phos-
phepane ipso-Ph), 210.5 (dd, 2JP, C =10.1, 2JP, C =11.4 Hz; COax), 214.0 (dd,
2
2JP, C =10.1, 2JP,C =31.7 Hz; COeq), 216.2 ppm (dd, 2JP, C =10.3, JP, C
=
26.4 Hz; COeq); 31P NMR (CDCl3): d=ꢀ149.1 (d, 2JP, P =58.7 Hz; phos-
phirane), 140.4 ppm (d, 2JP, P =58.7 Hz; phosphepane); HR-MS: calcd for
C22H22MoN2O4P2: 538.0109; found 538.00991 (d 6”10ꢀ3); IR (CH2Cl2):
n˜ =2017 (m) (n(CO)), 1900 (s) (n(CO)); EI-MS: m/z (%): 538 (10) [M+],
510 (8) [M+ꢀCO], 482 (10) [M+ꢀ2CO], 454 (10) [M+ꢀ3CO], 426 (45)
[M+ꢀ4CO], 374 (45) [M+ꢀ2COꢀPPh], 318 (45) [M+ꢀphosphepine].
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A
tion of 17 (0.35 g, 0.47 mmol) in toluene (3 mL) was stirred at 808C for
3 h. Evaporation to dryness and column chromatography (silica gel; di-
chloromethane/pentane, 2:1) followed by recrystallization from dichloro-
methane/hexane yielded 20 (0.15 g, 61%) as colorless crystals. M.p. 169–
1708C (decomp); 1H NMR (CDCl3): d=2.62 (d, 2JP, H =5.6 Hz, 2H; phos-
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2
2JP, C =2.0, JP, C =2.9 Hz; CH2), 128.6–132.0 (m; Ar), 132.9 (dd, 1JP, C =10.2,
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2
phosphepane ipso-Ph), 207.8 (m; COax), 212.9 (dd, 2JP, C =10.2, JP,C
=
29.8 Hz; COeq), 215.5 ppm (dd, 2JP, C =10.6, 2JP, C =32.7 Hz; COeq);
2
31P NMR (CDCl3): d=ꢀ150.6 (d, JP, P =66.8 Hz; phosphirane), 191.7 ppm
(d, 2JP, P =66.8 Hz; phosphepane); HR-MS calcd for C20H16MoO6P2:
511.9477; found 511.94668 (d 2”10ꢀ3); IR (CH2Cl2): n˜ =2031 (w)
(n(CO)), 1919 cmꢀ1 (s) (n(CO)); EI-MS: m/z (%): 512 (40) [M+], 484 (4)
[M+ꢀCO], 456 (16) [M+ꢀ2CO], 428 (28) [M+ꢀ3CO], 400 (100) [M+
ꢀ4CO].
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Chem. Eur. J. 2006, 12, 4333 – 4340