Imino- and oxazolino-functionalised pyrrolylphosphanes and pyrrolylphosphinites: An unexploited class of chiral P,N-bidentate ligands with unusual electronic properties

Article abstract of DOI:10.1002/ejic.200500075

Enantiopure P,N-bidentate pyrrolylphosphanes and pyrrolylphosphinites have been prepared based upon chiral imino-and oxazolino-containing compounds. Complexation of the new ligands with [Rh(CO)₂Cl]₂ and [Pd(allyl)Cl]₂ has been found to give the chelate complexes [Rh(CO)Cl(η²-P,N)] and [Pd(allyl)(η²-P,N)] ⁺BF₄^-, respectively. Imino- and oxazolino-functionalised pyrrolylphosphanes and pyrrolylphosphinites have been shown to be a novel class of P,N-bidentate ligands possessing exceptional π-acceptor and original σ-donor properties. With these ligands, up to 77 % ee has been achieved in the asymmetric Pd-catalyzed sulfonylation of 1,3-diphenyl-2-propenyl acetate with sodium p-toluenesulfinate. In the enantioselective alkylation of 1,3-diphenyl-2-propenyl acetate with dimethyl malonate, up to 93 % enantioselectivity has been achieved by using [Pd(allyl)(η²-P,N)]⁺BF₄^- complexes as chiral catalysts. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.

Full text of DOI:10.1002/ejic.200500075

FULL PAPER
Imino- and Oxazolino-Functionalised Pyrrolylphosphanes and
Pyrrolylphosphinites: An Unexploited Class of Chiral P,N-Bidentate Ligands
with Unusual Electronic Properties
Konstantin N. Gavrilov,[a] Vasily N. Tsarev,*[b] Stanislav I. Konkin,[a] Sergey E. Lyubimov,[b]
Alexander A. Korlyukov,[b] Mikhail Yu. Antipin,[b] and Vadim A. Davankov[b]
Keywords: Allylic substitution / Asymmetric catalysis / Palladium / P, N -bidentate ligands / Rhodium
Enantiopure P,N-bidentate pyrrolylphosphanes and pyrrolyl-
phosphinites have been prepared based upon chiral imino-
and oxazolino-containing compounds. Complexation of the
new ligands with [Rh(CO)2Cl]2 and [Pd(allyl)Cl]2 has been
found to give the chelate complexes [Rh(CO)Cl(η2-P,N)] and
[Pd(allyl)(η2-P,N)]+BF4–, respectively. Imino- and oxazolino-
functionalised pyrrolylphosphanes and pyrrolylphosphinites
have been shown to be a novel class of P,N-bidentate ligands
possessing exceptional π-acceptor and original σ-donor prop-
erties. With these ligands, up to 77% ee has been achieved in
the asymmetric Pd-catalyzed sulfonylation of 1,3-diphenyl-2-
propenyl acetate with sodium p-toluenesulfinate. In the
enantioselective alkylation of 1,3-diphenyl-2-propenyl ace-
tate with dimethyl malonate, up to 93% enantioselectivity
–
has been achieved by using [Pd(allyl)(η2-P,N)]+BF4 com-
plexes as chiral catalysts.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2005)
Introduction
onance form D would also be expected to contribute in an
electron-withdrawing fashion, since a more electronegative
nitrogen atom replaces carbon.[3] As a result, the substitu-
ent parameter χi for the 1-pyrrolyl functionality is approxi-
mately 12, and the π-acceptor character of these ligands is
thus found to exceed that of arylphosphites (–OPh, χi = 9.7)
and fluorinated aromatic phosphanes (–C6F5 χi = 11.2).[3]
The higher frequencies of the metal carbonyl stretch for
rhodium complexes with pyrrolylphosphanes and pyrrolyl-
phosphonites compared with rhodium complexes with
phosphites (Table 1) are consistent with pyrrolyl-based li-
gands being a better π-acceptor than phosphites, as antici-
pated from the greater number of 1-pyrrolyl substituents,
which reduces the back-donation to the metal carbonyl.
In the last decade, (1-pyrrolyl)phosphanes (PPhx-
(NC4H4)3–x, x = 0–2), phosphinites and phosphonites
(P(OPh)x(NC4H4)3–x, x = 1–2) have been successfully ap-
plied in the synthesis of rhodium[1–7] and cobalt[8] com-
plexes, as well as in Rh-catalyzed hydroformylation.[9,10]
A
set of spectroscopic, structural, and thermochemical mea-
surements[1–7,10] showed that these substances are excep-
tional π-acceptor ligands. The rationale for this π-acceptor
character is best demonstrated by the resonance forms A–
D, Figure 1.
Aromatic delocalisation of the nitrogen lone pair into the
five-membered ring places a partial positive charge adjacent
to the phosphorus atom. This contribution in B and C
would be expected to render the pyrrolyl substituent an ef-
1
As for σ basicity, the JP,Se coupling constants in the 31P
fective electron-withdrawing group. Relative to phenyl, res- NMR spectra of corresponding selenide derivatives indicate
Figure 1. Resonance forms of pyrrolylphosphanes.
that P(NC4H4)3 (1JP,Se for Se=P(NC4H4)3 = 970 Hz) is
[a] Department of Chemistry, Ryazan State Pedagogic University,
46 Svoboda str., Ryazan, 390000, Russia
Fax: +7-0912-775-498
more basic than P(OPh)3 and constrained phosphites (1JP,Se
for Se=L = 1099–1011 Hz) and less basic than P(NR2)3
(1JP,Se for Se=L = 854–784 Hz).[6] For estimating the σ ba-
sicity of pyrrolylphosphanes, we suggest a well-known crite-
E-mail: chem@ttc.ryazan.ru
[b] Institute of Organoelement Compounds, Russian Academy of
Sciences,
28 Vavilova str., Moscow, 119991, Russia
Fax: +7-095-135-6471
E-mail: tsarev@ineos.ac.ru
1
rion that the values of JP,Rh coupling constants in the 31P
NMR spectra of corresponding chlorocarbonyl complexes
Eur. J. Inorg. Chem. 2005, 3311–3319
DOI: 10.1002/ejic.200500075
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V. N. Tsarev et al.
FULL PAPER
Table 1. Spectroscopic data for the complexes [Rh(acac)(CO)L] and trans-[RhCl(CO)L2].
Complex
ν(CO) [cm–1] (CH2Cl2)
1JP,Rh, [Hz] (CDCl3)
[Rh(acac)(CO){P(NC4H4)3}][5]
[Rh(acac)(CO){P(OPh)3}][4,5]
[Rh(acac)(CO){P(OEt)3}][11]
[Rh(CO){P(NC4H4)3}2Cl][1,2]
[Rh(CO){P(NC4H4)2(OPh)}2Cl][10]
[Rh(CO){P(OPh)3}2Cl][2]
2012
2006
1990
2024
2018
2016
251
293
267
180
190
210
of rhodium(i) strongly correlate with the s character of the
phosphorus lone pair.[11,12] According to this criterion, pyr-
rolylphosphanes are strong σ bases comparable not only
with P(OPh)3 and constrained phosphites, but also with al-
kyl phosphites (Table 1). A possible reason is a significant
contribution of the resonance form with partial negative
charge at the phosphorus atom, and easy polarization of
1
1
the aromatic group.[13] Values of JP,Se and JP,Rh seem to
be more correct criteria for σ basicity than the bond lengths
Rh–P used by some authors.[14] On the basis of the X-ray
data for the isostructural complexes [Rh(acac)(CO){P-
(OPh)3}] (Rh–P 2.170 Å) and [Rh(acac)(CO){P(NC4H4)3}]
(Rh–P 2.166 Å), they made a conclusion about stronger σ-
donor properties of P(OPh)3 in comparison to P(NC4H4)3.
However, bond lengths M–P are dependent not only on σ
basicity, but also on π acidity of the ligand.[6] Thus, in an-
other pair of isostructural compounds [Rh(acac)-
{P(OPh)3}2] (Rh–P 2.147, 2.156 Å) and [Rh(acac)-
{P(NC4H4)3}2] (Rh–P 2.161, 2.176 Å), bonds Rh–P are
longer in the complex with P(NC4H4)3,[4] while 1JP,Rh is 291
and 261 Hz, respectively (compare also with the data in
Table 1).
Therefore, pyrrolylphosphanes and pyrrolylphosphinites
are characterised by rather paradoxical electronic proper-
ties, and are both more potent π acids and σ bases than
phosphites, representing a novel and efficient group of op-
tically active ligands.[15–17] It should be noted that the
–P(NC4H4)2 building block and the common chiral ligand
–PPh2 fragment are practically the same size, according to
their Tolman’s cone angle values.[1,4] One could expect that
such unusual electronic and steric properties of ligands
with –P(NC4H4)2 fragments make these compounds prom-
ising for asymmetric catalysis, but to the best of our knowl-
edge no examples of their catalytic application are known.
In the present communication we report previously un-
known chiral pyrrolylphosphanes and pyrrolylphosphinites
and pioneering results of their application in the coordina-
tion chemistry of palladium and in asymmetric Pd-cata-
lysed allylation.
Scheme 1.
Compounds 2a–e are soluble in common nonprotic sol-
vents and stable under dry conditions. Unlike P(NC4H4)3,
ligands 2d and 2e are moisture sensitive. A possible reason
for this, as in the case of the keto-functionalised ligand
P(NC4H4)2(NC4H3C(O)Me-2),[7] is that a functionalised
pyrrole ring represents a better leaving group than the un-
functionalised pyrrolyl groups and, additionally, is able to
form hydrogen bonds with incoming protic nucleophiles.
Using the compounds 2a–e, neutral and cationic cis-che-
late metal complexes were obtained (Scheme 2).
Some important spectroscopic data of the complexes are
summarised in Table 2.
1
The JP,Rh and ν(CO) data for complexes 3a–e are in
good agreement with the suggested structures.[18] IR and
13C NMR spectroscopic characteristics of the carbonyl li-
1
gands in complexes 3a–e (δC = 186.2 ppm, JC,Rh = 72 Hz,
Results and Discussion
2J(C,P) = 16 Hz for 3a and δC = 184.9 ppm, JC,Rh
=
1
2
The new P, N -bidentate pyrrolylphosphinites 2a–c and 68 Hz, JC,P = 17 Hz for 3e) indicate that 2a–e represent a
pyrrolylphosphanes 2d,e were obtained from chlorobis(1- novel group of highly π-accepting P, N -bidentate li-
pyrrolyl)phosphane in one step (Scheme 1).
gands.[4,7,19] Notably, the ν(CO) values of 3d,e prove that
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Imino- and Oxazolino-Functionalised Pyrrolylphosphanes and Pyrrolylphosphinites
FULL PAPER
supports a general conclusion about higher σ-donor and π-
acceptor properties of pyrrolylphosphanes and pyrrolylpho-
sphinites with respect to phosphites.
It is rather difficult to determine the best σ donor among
1
the ligands 2a–e, since the JP,Rh values in chloro carbonyl
rhodium chelate complexes depend largely on the nature of
a nitrogen-containing fragment (see ref.[18] and references
cited therein). But in the case of 3c and 3d, the 31P NMR
spectroscopic data (Table 2) indicate that pyrrolylphos-
phane 2d is a stronger σ donor than pyrrolylphosphinite 2c.
Complexes 3a, 3c and 3d were characterised by X-ray
diffraction. Their molecular structures are shown in Fig-
ure 2, Figure 3 and Figure 4, and selected bond lengths and
angles are given in Table 4.
Scheme 2.
Table 2. Selected spectroscopic data for compounds 3a–e and 4a–e
(in CHCl3).
Compound
31P NMR Spectroscopy
IR Spectroscopy
δP
1J(P,Rh) [Hz]
ν(CO) [cm–1]
3a
3b
3c
3d
3e
4a
4b
4c
4d
4e
116.7
116.3
126.2
93.4
94.9
242
242
256
245
249
–
–
–
–
–
2032
2034
2036
2039
2040
–
–
–
–
–
113.1, 112.6
115.6, 115.1
125.5, 124.7
89.3, 88.8
92.5
ligands 2d,e bearing three pyrrole rings, are the most π
1
acidic in the group. A comparison of the JP,Rh and ν(CO)
data for compounds 3a–c (Table 2) and isostructural rho-
dium complexes previously described by us[18,20,21] (Table 3)
Table 3. Selected spectral parameters for [Rh(CO)Cl(η2-P, N )] com-
plexes with P, N -bidentate arylphosphite ligands.
Figure 2. Molecular structure of complex 3a. Atoms are given by
thermal ellipsoids at 50% probability. Principal bonds and angles
(Å and °): Rh(1)–C(1K) 1.837(3), Rh(1)–N(1) 2.141(2), Rh(1)–P(1)
2.1576(8), Rh(1)–Cl(1) 2.3742(9), P(1)–O(1) 1.598(2), P(1)–N(1P)
1.691(2), P(1)–N(1PЈ) 1.703(2), O(1)–C(1) 1.444(3), O(1K)–C(1K)
1.134(4); O(1)–P(1)–N(1P) 103.34(12), O(1)–P(1)–N(1PЈ) 96.27(12),
N(1P)–P(1)–N(1PЈ) 100.49(11), O(1)–P(1)–Rh(1) 116.68(8), N(1P)–
P(1)–Rh(1) 116.72(8), N(1PЈ)–P(1)–Rh(1) 119.95(9).
From X-ray studies it was found that in the crystal the
molecules of 3a,c,d are characteried by S configurations of
C(2) and C(3) for 3a, C(4) and C(5) for 3c, and C(4) and
C(5) for the 3d asymmetric atoms, respectively.
The distorted sofa conformation (the deviation of the
P(1) atom from the basal plane is 0.81 Å) of the six-mem-
bered metallacycle is observed in compound 3d. In com-
pound 3a, where the fused five-membered cyclic fragments
are absent, the six-membered metallacycle adopts the dis-
torted chair conformation with deviations of the P(1) and
C(2) atoms by 0.57 and 0.79 Å, respectively. The chair con-
formation of the six-membered metallacycle is also ob-
served in previously studied complexes with the 1,3-diaza-
2-phosphabicyclo[3.3.0]octane ligand.[22] So, it can be con-
cluded that the distorted sofa conformation in 3d is caused
by the presence of five-membered cycles fused with the
metallacycle.
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V. N. Tsarev et al.
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Table 4. Selected bond lengths [Å] and angles [°] for complexes 3a,
3c and 3d.
3a
3c
3d
Rh(1)–C(1K)
Rh(1)–N(1)
Rh(1)–P(1)
Rh(1)–Cl(1)
O(1K)–C(1K)
N(1)–Rh(1)–P(1)
C(1K)–Rh(1)–P(1)
C(1K)–Rh(1)–Cl(1)
N(1)–Rh(1)–Cl(1)
P(1)–Rh(1)–Cl(1)
1.837(3)
2.141(2)
2.158(1)
2.374(1)
1.134(4)
88.36(7)
89.81(9)
89.00(9)
92.67(7)
177.35(3)
1.828(3)
2.1019(19)
2.155(1)
2.381(1)
1.134(3)
90.20(6)
91.13(9)
89.48(9)
89.64(6)
176.05(2)
176.9(3)
1.838(3)
2.111(2)
2.145(1)
2.363(1)
1.129(4)
86.54(6)
93.67(10)
89.35(10)
90.64(6)
174.45(3)
178.1(3)
O(1K)–C(1K)–Rh(1) 178.0(3)
The oxazoline cycles in 3c and 3d have different confor-
mations. In the former case this cycle is planar, while in the
latter it adopts the envelope conformation with deviation of
the C(4) atom by 0.15 Å. The ferrocenyl substituent in 3a
occupies a pseudoequatorial position.
The endo-cyclic rhodium atom has an almost ideal
square-planar geometry, its deviation from the basal plane
does not exceed 0.02 Å. On the other hand in 4 the devia-
tion of the RhI atom from the basal plane is more pro-
nounced (0.06 Å), which may be explained by steric over-
crowding of the six-membered metallacycle. The P(1)–Rh(1)
bonds in 3a,c,d are somewhat shorter than those in the pre-
viously investigated 1,3-diaza-2-phosphabicyclo[3,3,0]oc-
Figure 3. Molecular structure of complex 3c. Atoms are given by
thermal ellipsoids at 50% probability. Principal bonds and angles
(Å and °): Rh(1)–C(1K) 1.828(3), Rh(1)–N(1) 2.1020(19), Rh(1)–
P(1) 2.1553(9), Rh(1)–Cl(1) 2.3810(9), P(1)–O(1P3) 1.6166(17),
P(1)–N(1P) 1.691(2), P(1)–N(1PЈ) 1.696(2), O(1K)–C(1K) 1.134(3);
O(1P3)–P(1)–N(1P) 94.72(10), O(1P3)–P(1)–N(1PЈ) 103.95(10),
N(1P)–P(1)–N(1PЈ) 102.73(10), O(1P3)–P(1)–Rh(1) 116.33(6),
N(1P)–P(1)–Rh(1) 119.85(8), N(1PЈ)–P(1)–Rh(1) 116.05(8).
The seven-membered metallacycle in 3c is fused with tane ligand complex[22]. On the other hand, the shortening
phenyl and oxazoline moieties and its conformation may be of the P(1)–Rh(1) bond did not lead to respective elong-
described as a distorted boat. Atoms C(1P3), C(6P3) and ation of the Rh(1)–Cl(1) bond in comparison to the analo-
Rh(1) deviate from the plane P(1)O(1P3)N(1)C(1) by 0.93, gous bond in the previously described complex.[22] So, the
0.98 and 0.68 Å, respectively.
trans-effect of a P(C4H4N)3 moiety is almost the same as
Figure 4. Molecular structure of complex 3d. Atoms are given by thermal ellipsoids at 50% probability. Principal bonds and angles (Å
and °): Rh(1)–C(1K) 1.838(3), Rh(1)–N(1) 2.111(2), Rh(1)–P(1) 2.1448(8), Rh(1)–Cl(1) 2.3631(9), P(1)–N(1P) 1.681(2), P(1)–N(1PЈ)
1.698(2), P(1)–N(1P3) 1.717(2), C(1K)–O(1K) 1.129(4); N(1P)–P(1)–N(1PЈ) 102.52(12), N(1P)–P(1)–N(1P3) 99.87(12), N(1PЈ)–P(1)–
N(1P3) 100.44(11), N(1P)–P(1)–Rh(1) 118.26(8), N(1PЈ)–P(1)–Rh(1) 121.83(9), N(1P3)–P(1)–Rh(1) 110.46(8).
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Imino- and Oxazolino-Functionalised Pyrrolylphosphanes and Pyrrolylphosphinites
FULL PAPER
in the case of the 1,3-diaza-2-phosphabicyclo[3.3.0]octane weaker than 2d,e. It is notable that whereas ν(CO) for the
fragment. rhodium complexes varies significantly from 1986 to
The geometry of the P(1) atom in 3a and 3c is distorted 2040 cm–1 (Δν(CO) = 54 cm–1), Δ1J
does not exceed a
˜
C,Rh
tetrahedral, the bond angles at this atom vary in the range mere 6 Hz (Table 5). Moreover, the ν(CO) magnitudes of
˜
of 94–119°. It should be noted that endocyclic P–O bonds [Rh(CO)(P(Ph)2(7-aza-N-indolyl))Cl]
and
[Rh(CO)-
in 3a,c,d have almost the same lengths as in previously (P(NC4H4)2(7-aza-N-indolyl)Cl] differ by 22 cm–1, while
studied compound.[22]
their 1JC,Rh values are equal. These facts are in good agree-
1
1
There is no correlation between JP,Rh values and Rh–P ment with a conclusion made earlier by us that JC,Rh for
bond lengths, because, as mentioned above, the Rh–P bond cis-P, N -chelate chlorocarbonyl complexes [Rh(CO)(L)Cl]
length depends not only on σ basicity but also on the π lie within a narrow interval of 68–75 Hz and are practically
acidity of the P ligand. Thus, the shortest Rh–P bonds were indifferent to electronic characteristics of a phosphorus
found in the complexes with the most π-acceptor pyrrolyl- atom environment.[20] Duplication of peaks in the 31P
phosphanes
[Rh(CO)(P(NC4H4)2(NC4H3C(O)Me-2))Cl] NMR spectra of compounds 4a–d (Table 2) indicates the
1
[2.147 Å, JP,Rh = 237 Hz, ν(CO) = 2017 cm–1 (KBr)],[7] presence of their exo- and endo-isomers.[18,21] Sharp singlets
˜
[Rh(CO)(P(NC4H4)2(7-aza-1-indolyl))Cl] and 3d (Table 5); in the 31P NMR spectrum of 4e can be rationalised either
3d has the shortest Rh–P bond among these complexes and by fast interconversion of the isomers or by an absence of
related compounds like [Rh(acac)(CO){P(NC4H4)3}]. The one of them.
data in Table 5 clearly demonstrate that ν(CO) in the IR
Pyrrolylphosphanes and pyrrolylphosphinites 2a–e and
spectra of [Rh(CO)(L)Cl] complexes is strongly affected by complexes 4c,d were tested in asymmetric Pd-catalysed al-
changings in the π acidity of P, N -bidentate ligands. In par- lylic substitution reactions (Scheme 3).
ticular, pyrrolylphosphane P(NC4H4)2(7-aza-1-indolyl) is a
The results of allylic sulfonylation are summarised in
much stronger π acceptor than P(Ph)2(7-aza-1-indolyl), but Table 6. Good optical (up to 77% ee) and moderate chemi-
Table 5. Some spectral and structural parameters of cis-P, N -chelate chlorocarbonyl complexes [Rh(CO)(L)Cl].
Eur. J. Inorg. Chem. 2005, 3311–3319
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V. N. Tsarev et al.
FULL PAPER
Scheme 3.
cal (up to 60%) yields of product 6 were achieved. 2b (entry demonstrated moderate enantioselectivity (up to 64% ee)
5) was found to be the most stereoselective ligand, while 2a, with substantially low conversion in the case of 2d. In con-
2c and 2e showed basically the same enantioselectivity (54– trast to allylic sulfonylation, [Pd(allyl)Cl]2 was a superior
64%), and no conversion was observed with 2d (entries 10– catalyst precursor for all ligands.
12). An increased L*/Pd molar ratio in the processes cata-
lysed by [Pd(allyl)Cl]2 resulted in higher optical and chemi-
Conclusions
cal yields (entries 1,2; 4,5). Worth noting is that the most
successful catalyst precursor for 2c happened to be
[Pd2(dba)3]×CHCl3 (entries 7–9).
Several chiral imino- and oxazolino-functionalised pyr-
rolylphosphanes and pyrrolylphosphinites were obtained
for the first time by a simple one-step synthesis. These com-
pounds have been shown to be a novel class of P, N -biden-
tate ligands possessing exceptional π-acceptor and original
σ-donor properties. The new ligands were used in asymmet-
ric Pd-catalyzed allylic substitution where up to 93% ee was
achieved in the benchmark test with 1,3-diphenyl-2-pro-
penyl acetate and dimethyl malonate. It should be pointed
out, however, that the present work describes only five sub-
stances in this general class. A tremendous variety of similar
substituents such as substituted pyrroles, indoles, imida-
zoles, pyrazoles, etc., are commercially available or obtain-
able by synthetic means.[1] The simple synthesis of pyrrolyl-
phosphanes and pyrrolylphosphinites, their outstanding
electronic properties, together with the wide variety of ac-
cessible pyrrolelike precursors make it an attractive area of
research with great promise.
Table 6. Enantioselective allylic sulfonylation of 5 with NaSO2pTol
(in THF).
Entry Catalyst precursor
Ligand L*/Pd Isolated ee [%][a]
yield [%]
1
2
3
4
5
6
7
8
[Pd(allyl)Cl]2
[Pd(allyl)Cl]2
[Pd2(dba)3]×CHCl3
[Pd(allyl)Cl]2
[Pd(allyl)Cl]2
[Pd2(dba)3]×CHCl3
[Pd(allyl)Cl]2
[Pd(allyl)Cl]2
[Pd2(dba)3]×CHCl3
[Pd(allyl)Cl]2
[Pd(allyl)Cl]2
2a
2a
2a
2b
2b
2b
2c
2c
2c
2d
2d
2d
2e
2e
1:1
2:1
1:1
1:1
2:1
1:1
1:1
2:1
1:1
1:1
2:1
1:1
1:1
2:1
17
60
16
0
26
15
37
30
25
0
0
0
22
31
32 (R)
64 (R)
33 (R)
–
77 (R)
15 (S)
7 (S)
7 (S)
54 (S)
–
9
10
11
12
13
14
–
–
[Pd2(dba)3]×CHCl3
[Pd(allyl)Cl]2
[Pd(allyl)Cl]2
57 (R)
58 (R)
[a] ee measured by HPLC [(R,R)-Whelk-01, hexane/iPrOH = 4:1,
1 mL/min, 254 nm].
Experimental Section
For the asymmetric allylic alkylation (Scheme 3, Table 7),
ligands 2a and 2c provided the best results (entries 1,2,5).
Thus, cationic complex 4c afforded the product in 93% ee
(93% conversion, entry 7).
General Remarks: All reactions were performed under argon in de-
hydrated solvents. IR spectra were recorded with a Specord M80
instrument. 31P and 13C NMR spectra were recorded with a Bruker
AMX 400 instrument (162.0 MHz for 31P, 100.6 MHz for 13C). The
assignments of the signals in the 13C NMR spectra were made with
the use of the DEPT technique and, for pyrrolyl substituents, using
literature data.[10] Chemical shifts (ppm) are given relative to Me4Si
(13C NMR) and 85% H3PO4 (31P NMR). Mass spectra were re-
corded with a Kratos MS890 spectrometer (EI), an MSVKh TOF
spectrometer with ionization by Cf-252 fission fragments (plasma
desorption technique, PD) and AMD 402 spectrometer (FAB). Op-
tical rotations were measured on a Perkin–Elmer 141 polarimeter.
Elemental analyses were performed at the Laboratory of Microa-
nalysis (Institute of Organoelement Compounds, Moscow).
[Rh(CO)2Cl]2,[25] [Pd(allyl)Cl]2,[26] [Pd2(dba)3]×CHCl3,[27] chlo-
robis(1-pyrrolyl)phosphane,[10] compounds 1a,[18] 1c,[28] 1d[29] and
1e[30] were synthesised using literature procedures. 4-Hy-
droxymethyl-2-methyl-5-phenyl-2-oxazoline (1b) was purchased
from Fluka. The syntheses of rhodium(i) complexes 3a–e and palla-
dium(ii) complexes 4a–e were performed by techniques similar to
that reported.[18,31]
Table 7. Enantioselective allylic alkylation of 5 with dimethyl ma-
lonate (in THF, L*/Pd = 1:1).
Entry
Catalyst
Conv. [%][a]
ee [%][b]
1
2
3
4
5
6
7
8
[Pd(allyl)Cl]2/2a
[Pd2(dba)3]×CHCl3/2a
[Pd(allyl)Cl]2/2b
[Pd2(dba)3]×CHCl3/2b
[Pd(allyl)Cl]2/2c
[Pd2(dba)3]×CHCl3/2c
4c
[Pd(allyl)Cl]2/2d
[Pd2(dba)3]×CHCl3/2d
4d
99
91
99
99
46
12
93
19
8
83 (R)
81 (R)
44 (R)
38 (R)
88 (S)
61 (S)
93 (S)
64 (S)
36 (R)
–
9
10
11
12
0
11
10
[Pd(allyl)Cl]2/2e
[Pd2(dba)3]×CHCl3/2e
80 (S)
67 (S)
[a] Measured by HPLC. [b] Determined by HPLC (Daicel Chiralcel
OD-H, hexane/iPrOH = 99:1; 0.5 mL/min, 254 nm).
Stereoinduction of pyrrolylphosphane 2e is close to 2a
NaSO2pTol, CH2(CO2Me)2 and N,O-bis(trimethylsilyl)acetamide
and 2c (entry 11), but conversion is low. Ligands 2b and 2d (BSA) were purchased from Acros Organics. Compound 5 was syn-
3316 © 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim www.eurjic.org
Eur. J. Inorg. Chem. 2005, 3311–3319

Imino- and Oxazolino-Functionalised Pyrrolylphosphanes and Pyrrolylphosphinites
FULL PAPER
thesised as published.[26] The catalytic experiments were carried out
according to published procedures.[22]
CHCl3). 13C NMR (CDCl3): δC = 148.8 (CH=N), 144.8, 128.2,
126.5, 126.3 (all CPh), 134.7 (d, 2J = 2.7 Hz), 126.6 (d, 2J = 4.2 Hz),
118.5, 112.1 (all CPyr), 122.5 (d, 2J = 14.4 Hz, CHNP), 122.2 (d,
Preparation of Ligands. General Technique: A solution of chlo-
robis(1-pyrrolyl)phosphane (4.2×10–3 mol) in benzene (15 mL) was
added dropwise to a stirred solution of the appropriate compound
1a–e (4.2×10–3 mol) and Et3N (0.6 mL, 4.2×10–3 mol) in the same
solvent (15 mL) at 0 °C. The reaction mixture was then heated to
boiling point, allowed to cool down, stirred for 0.5 h at 50 °C, al-
lowed to cool to room temperature and filtered. The solvent was
removed in vacuo (40 Torr), and the residue was concentrated and
dried in vacuo (1 Torr, 2 h).
3
2J = 14.0 Hz CHNP), 112.0 (d, J = 3.8 Hz, CHCHNP), 111.8 (d,
3J = 3.8 Hz, CHCHNP), 68.6 (CHN), 24.7 (CH3) ppm. 31P NMR
(CDCl3): δP = 68.7 ppm. MS (FAB): m/z (%): 360 (8) [M]+, 294
(44) [M – pyrrolyl]+, 105 (100). Elemental analysis for C21H21N4P
(360.2): calcd. C 69.99, H 5.87, N 15.55; found C 70.23, H 5.78, N
15.63.
Rhodium Complexes
[Rh(CO)(2a)Cl] (3a): Yield 0.22 g, 94%; red powder; m.p. 215–
216 °C (dec.). 13C NMR (CDCl3): δC = 171.8 (CH=N), 121.9
(CHNP), 113.1 (CHCHNP), 81.0 [CFc(ipso)], 76.1 (CHN), 73.3,
73.1, 72.8, 72.1 (all CFc), 70.9 (CH2OP), 69.7 (CCp), 36.9 (CHCH3),
25.2 (CH2CH3), 14.3 (CHCH3), 10.3 (CH2CH3) ppm. IR (KBr):
{(2S)-2-(Ferrocenylmethylideneamino)-2-[(1S)-1-methylpropyl]-
ethoxy}bis(1-pyrrolyl)phosphinite (2a): Yield: 1.85 g, 93%; dark red
oil. [α]2D1 = +151.4 (c = 0.5, CHCl3). 13C NMR (CDCl3): δC = 161.7
(CH=N), 121.1 (d, 2J = 14.9 H, CHNP), 120.9 (d, 2J = 14.7 Hz,
ν(CO) = 2019 cm–1. Elemental analysis for C H ClFeN O PRh
3
3
˜
26 30
3
2
CHNP), 111.7 (d, J = 6.5 Hz, CHCHNP), 111.6 (d, J = 6.1 Hz,
CHCHNP), 80.4 [CFc(ipso)], 76.3 (d, 3J = 5.3 Hz, CHN), 70.1, 69.9,
69.1, 67.5 (all CFc), 69.2 (d, 2J = 16.3 Hz, CH2OP), 68.7 (CCp), 36.1
(CHCH3), 25.2 (CH2CH3), 15.7 (CHCH3), 10.8 (CH2CH3) ppm.
31P NMR (CDCl3): δP = 113.6 ppm. MS (70 eV, EI): m/z (%): 475
(6) [M]+, 409 (64) [M – pyrrolyl]+, 264 (95), 121 (100). MS (PD):
m/z (%): 475 (80) [M]+, 409 (100) [M – pyrrolyl]+. MS (FAB): m/z
(%): 475 (16) [M]+, 409 (85) [M – pyrrolyl]+, 264 (100). Elemental
analysis for C25H30FeN3OP (475.2): calcd. C 63.17, H 6.36, N 8.84;
found C 63.31, H 6.29, N 8.71.
(641.0): calcd. C 48.66, H 4.71, N 6.55; found C 48.83, H 4.62, N
6.68.
[Rh(CO)(2b)Cl] (3b): Yield 0.17 g, 90%; light-brown powder; m.p.
208–210 °C (dec.). IR (KBr): ν˜(CO) = 2016 cm–1. Elemental analy-
sis for C20H20ClN3O3PRh (519.0): calcd. C 46.22, H 3.88, N 8.09;
found C 46.41, H 3.72, N 7.90.
[Rh(CO)(2c)Cl] (3c): Yield 0.18 g, 89%; orange powder; m.p. 199–
200 °C (dec.). IR (KBr): ν(CO) = 2022 cm–1. Elemental analysis for
˜
C22H24ClN3O3PRh (547.0): calcd. C 48.24, H 4.42, N 7.67; found
[(4S,5S)-(2-Methyl-5-phenyl-2-oxazolin-4-yl)methoxy]bis(1-pyrrol- C 48.45, H 4.51, N 7.53.
yl)phosphinite (2b): Yield 1.33 g, 90%; light yellow oil. [α]2D1
=
[Rh(CO)(2d)Cl] (3d): Yield 0.17 g, 92%; light-brown powder; m.p.
–158.3 (c = 1, CHCl3). 13C NMR (CDCl3): δC = 166.0 (C=N),
139.8, 128.5, 128.1, 125.1 (all CPh), 121.0 (d, 2J = 10.3 Hz, CHNP),
207–208 °C (dec.). IR (KBr): ν(CO) = 2025 cm–1. Elemental analy-
˜
sis for C20H23ClN4O2PRh (520.0): calcd. C 46.13, H 4.45, N 10.76;
found C 46.29, H 4.33, N 10.61.
3
120.9 (d, 2J = 10.1 Hz, CHNP), 111.9 (d, J = 5.3 Hz, CHCHNP),
111.8 (d, 3J = 5.0 Hz, CHCHNP), 82.6 (CHO), 74.6 (d, 3J =
6.5 Hz, CHN), 68.3 (d, 2J = 18.3 Hz, CH2OP), 13.5 (CH3) ppm.
31P NMR (CDCl3): δP = 114.5 ppm. MS (PD): m/z (%): 353 (7)
[M]+, 313 (55), 101 (100). MS (FAB): m/z (%): 353 (2) [M]+, 287
(100) [M – pyrrolyl]+ , 182 (83). Elemental analysis for
C19H20N3O2P (353.1): calcd. C 64.58, H 5.70, N 11.89; found C
64.39, H 5.77, N 12.01.
[Rh(CO)(2e)Cl] (3e): Yield 0.17 g, 90%; brown powder; m.p. 186–
188 °C (dec.). 13C NMR (CDCl3): δC = 152.9 (CH=N), 140.9,
2
2
128.8, 127.8, 127.5 (all CPh), 131.5 (d, J = 16.0 Hz), 126.4 (d, J
3
2
= 4.4 Hz), 114.4, 110.5 (d, JC,P = 9.2 Hz) (all CPyr), 123.1 (d, J =
10.4 Hz, CHNP), 122.9 (d, 2J = 10.4 Hz, CHNP), 114.0 (d, 3J =
5.6; CHCHNP), 113.9 (d, 3J = 6.4 Hz, CHCHNP), 63.9 (CHN),
21.1 (CH ). IR (KBr): ν(CO) = 2010 cm–1. Elemental analysis for
˜
3
{2-[(4S)-4-sec-Butyl-2-oxazolin-2-yl]phenoxy}bis(1-pyrrolyl)phos-
phinite (2c): Yield 1.46 g, 92%; light yellow oil. [α]2D1 = –17.5 (c =
C22H21ClN4OPRh (526.0): calcd. C 50.16, H 4.02, N 10.64; found
C 50.32, H 3.93, N 10.51.
2
1, CHCl3). 13C NMR (CDCl3): δC = 160.6 (C=N), 151.4 (d, J =
Palladium Complexes
2
10.3 Hz), 132.0, 130.9, 124.4, 120.6, 116.4 (all CAr), 121.6 (d, J =
[Pd(2a)(allyl)]+BF4– (4a): Yield 0.25 g, 90%; red powder; m.p. 170–
172 °C (dec.). MS (FAB): m/z (%): 622 (100) [M – BF4]+, 581 (8)
[M – BF4 – allyl]+, 409 (22). Elemental analysis calcd. (%) for
C28H35BF4FeN3OPPd (709.1): C, 47.39; H, 4.97; N, 5.92; found:
C, 47.57; H, 6.08; N, 6.11.
15.9 Hz, CHNP), 121.5 (d, 2J = 16.4 Hz, CHNP), 111.9 (d, 3J =
5.0 Hz, CHCHNP), 111.8 (d, 3J = 4.6 Hz, CHCHNP), 71.3 (CHN),
69.1 (CH2O), 38.8 (CHCH3), 25.7 (CH2CH3), 14.2 (CHCH3), 11.2
(CH2CH3) ppm. 31P NMR (CDCl3): δP = 107.6 ppm. MS (PD):
m/z (%): 381 (7) [M]+, 315 (49) [M – pyrrolyl]+, 217 (100). Elemen-
tal analysis for C21H24N3O2P (381.2): calcd. C 66.13, H 6.34, N
11.02; found C 66.38, H 6.29, N 11.11.
[Pd(2b)(allyl)]+BF4 (4b): Yield 0.21 g, 88%; light-brown powder;
–
m.p. 162–164 °C (dec.). MS (FAB): m/z (%): 500 (100) [M – BF4]+,
459 (17) [M – BF4 – allyl]+, 287 (47). Elemental analysis for
C22H25BF4N3O2PPd (587.1): calcd. C 44.96, H 4.29, N 7.15; found
C 45.21, H 4.41, N 7.29.
{2-[(4S)-4-sec-Butyl-2-oxazolin-2-yl]-(1-pyrrolyl)}bis(1-pyrrolyl)-
phosphane (2d): Yield 1.32 g, 89%; light orange oil. [α]2D1 = –36.1 (c
= 1, CHCl3). 13C NMR (CDCl3): δC = 156.7 (C=N), 126.4 (d, J
2
2
[Pd(2c)(allyl)]+BF4 (4c): Yield 0.22 g, 91%; deep-orange powder;
–
= 3.8 Hz), 124.7 (d, J = 8.7 Hz), 117.3, 111.7 (all CPyr), 122.6 (d,
2J = 15.2 Hz, CHNP), 122.2 (d, 2J = 14.4 Hz, CHNP), 112.4 (d, 3J
= 4.2 Hz, CHCHNP), 112.2 (d, 3J = 4.2 Hz, CHCHNP), 71.3
(CHN), 69.9 (CH2O), 39.1 (CHCH3), 25.4 (CH2CH3), 14.3
(CHCH3), 11.2 (CH2CH3) ppm. 31P NMR (CDCl3): δP = 71.9 ppm.
MS (PD): m/z (%): 354 (12) [M]+, 288 (36) [M – pyrrolyl]+, 193
(100). Elemental analysis for C19H23N4OP(354.2): calcd. C 64.39,
H 6.54, N 15.81; found C 64.12, H 6.63, N 15.96.
m.p. 169–171 °C (dec.). MS (FAB): m/z (%): 528 (100) [M – BF4]+,
487 (9) [M – BF4 – allyl]+, 315 (95). Elemental analysis for
C24H29BF4N3O2PPd (615.1): calcd. C 46.82, H 4.75, N 6.82; found
C 47.05, H 4.62, N 6.69.
[Pd(2d)(allyl)]+BF4 (4d): Light-brown powder; 0.21 g, 90% yield;
–
m.p. 168–170 °C (dec.). MS (FAB): m/z (%): 501 (100) [M – BF4]+,
460 (19) [M – BF4 – allyl]+, 193 (95). Elemental analysis for
C22H28BF4N4OPPd (588.1): calcd. C 44.89, H 4.79, N 9.52; found
C 45.18, H 4.86, N 9.65.
{2-[(1R)-1-Phenylethyliminomethyl]-(1-pyrrolyl)}bis(1-pyrrolyl)phos-
phane (2e): Yield 1.31 g, 87%; red oil. [α]2D1 = +68.0 (c = 0.8,
Eur. J. Inorg. Chem. 2005, 3311–3319
www.eurjic.org
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
3317

V. N. Tsarev et al.
FULL PAPER
[Pd(2e)(allyl)]+BF4 (4e): Yield 0.21 g, 89%; deep-brown powder;
–
filtrate was evaporated at reduced pressure (40 Torr) giving, after
m.p. 173–175 °C (dec.). MS (FAB): m/z (%): 507 (100) [M – BF4]+, in vacuo desiccation (10 Torr, 12 h), product 7 as a colourless oil
466 (24) [M – BF4 – allyl]+, 199 (97). Elemental analysis for solidifying upon standing. All spectroscopic data of compound 7
C24H26BF4N4PPd (594.1): calcd. C 48.47, H 4.41, N 9.42; found C
48.61, H 4.52, N 9.55.
were in good agreement with the literature.[33]
X-ray Crystallographic Study: Crystallographic data for 3a, 3c and
3d are presented in Table 8. All X-ray diffraction measurements
were carried out with a SMART 1000 CCD diffractometer at
100 K. The frames were corrected for absorption by the SADABS
program.[34]
Catalytic Experiments
Palladium-Catalysed Allylic Sulfonylation of 1,3-Diphenylallyl Ace-
tate with Sodium p-Toluenesulfinate: A solution of [Pd(allyl)Cl]2
(0.0037 g, 0.01 mmol) or [Pd2(dba)3]×CHCl3 (0.0103 g, 0.01 mmol)
and the appropriate ligand (0.02–0.04 mmol) in THF (5 mL) was
stirred for 40 min. 1,3-Diphenylallyl acetate 5 (0.1 mL, 0.5 mmol)
was added to the solution and the reaction mixture was stirred for
15 min. Sodium p-toluenesulfinate (0.178 g, 1.00 mmol) was then
added and the reaction mixture was stirred for 48 h, quenched with
brine (10 mL) and extracted with THF (3×7 mL). The organic
layer was washed with brine (2×7 mL) and dried over MgSO4. The
solvent was evaporated at reduced pressure (40 Torr). Crystalli-
zation of the residue from EtOH followed by desiccation in vacuo
(10 Torr, 12 h) gave the product 6 as white crystals. All spectro-
scopic data of compound 6 were in good agreement with the litera-
ture.[32]
The principal experimental and crystallographic parameters are
presented in Table 8. The structures of 3a,c,d were solved by direct
methods and refined by full-matrix techniques against F2 in aniso-
tropic approximations using the SHELXTL 5.1 program pack-
age.[35] The positions of hydrogen atoms were calculated geometri-
cally and included in refinement in the rigid body approximation.
The absolute configuration of 3a,c,d was determined by using the
Flack parameter. CCDC-261125 (for 3a), -261126 (for 3c) and
-261124 (for 3d) contain supplementary crystallographic data for
this paper. These data can be obtained free of charge at
www.ccdc.acm.ac.uk/retrieving.html or from the Cambridge Crys-
tallographic Data Centre 12, Union Road, Cambridge CB2 1EZ,
UK [Fax: +44-1223-336033].
Palladium-Catalysed Allylic Alkylation of 1,3-Diphenylallyl Acetate
with Dimethyl Malonate: A solution of [Pd(allyl)Cl]2 (0.0037 g,
0.01 mmol) or [Pd2(dba)3]×CHCl3 (0.0103 g, 0.01 mmol) and the
appropriate ligand (0.02 mmol) in THF (5 mL) was stirred for
40 min [alternatively, the appropriate presynthesised complex
(0.02 mmol) was dissolved in THF (5 mL)]. 1,3-Diphenylallyl ace-
tate 5 (0.1 mL, 0.50 mmol) was added to the solution and the reac-
tion mixture was stirred for 15 min. Dimethyl malonate (0.10 mL,
0.87 mmol), BSA (0.22 mL, 0.87 mmol), and sodium acetate
(0.002 g) were also added. The reaction mixture was stirred for
48 h, diluted with THF (5 mL) and filtered through Celite. The
Acknowledgments
The authors thank Dr. P.V. Petrovskii (Institute of Organoelement
Compounds, Moscow) for assistance in characterising the products
and Dr. A.V. Korostylev (Leibniz-Institut für Organische Katalyse
an der Universitat Rostock, Germany) for assistance in preparation
of the manuscript. The authors gratefully acknowledge receiving
the chiral HPLC columns (R,R) WHELK-01 from Regis Technol-
ogies (USA) and Chiralcel OD-H from Daicel Chemical Industries,
Table 8. The principal experimental and crystallographic parameters of structures 3a, 3c and 3d.
3a
3c
3d
Molecular formula
Formula mass
Colour
Dimension [mm]
Crystal system
Space group
a [Å]
C26H30ClFeN3O2PRh
641.71
red
C22H24ClN3O3PRh
547.77
red
C20H23ClN4O2PRh
520.75
yellow
0.40×0.10×0.10
orthorhombic
P212121
8.448(3)
13.009(5)
24.601(9)
2703.7(17)
4
1.576
120
1.77/30.00
ω
0.50×0.05×0.05
orthorhombic
P212121
9.734(3)
10.459(3)
23.548(7)
2397.3(13)
4
1.518
293
1.73/29.96
ω
0.20×0.10×0.10
orthorhombic
P212121
8.704(2)
10.883(3)
23.190(6)
2196.8(10)
4
1.575
120
2.07/30.02
ω
b [Å]
c [Å]
V [Å3]
Z
ρcalcd. [g/cm3]
Temperature [K]
Min./max. 2Θ [°]
Scan type
Radiation, λ(Mo-Kα) [Å]
Linear absorption (μ) [cm–1]
Tmin./Tmax.
0.71073
13.33
0.8782/0.6177
1304
0.71073
9.18
0.9555/0.6568
1112
0.71073
9.95
0.9070/0.8258
1056
F(000)
Total refl. (Rint
Number of independent reflections
)
21171 (0.0219)
7594
28694 (0.0369)
6928
17056 (0.0309)
6391
Number of independent refl. with I Ͼ 2σ(I) 6928
5792
280
6008
264
Parameters
318
wR2
0.0785
0.0306
0.996
0.0479
0.0271
0.990
0.0892
0.0329
1.025
R1 [for reflections with I Ͼ 2σ(I)]
GOF
Flack parameter
–0.032(16)
1.676/–0.407
–0.031(18)
0.530/–0.241
–0.04(2)
1.925/–1.120
ρmax./ρmin., [e/Å3]
3318
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
Eur. J. Inorg. Chem. 2005, 3311–3319

Imino- and Oxazolino-Functionalised Pyrrolylphosphanes and Pyrrolylphosphinites
FULL PAPER
[18] K. N. Gavrilov, O. G. Bondarev, R. V. Lebedev, A. A. Shiryaev,
S. E. Lyubimov, A. I. Polosukhin, G. V. Grintselev–Knyazev,
K. A. Lyssenko, S. K. Moiseev, N. S. Ikonnikov, V. N. Kalinin,
V. A. Davankov, A. V. Korostylev, H.-J. Gais, Eur. J. Inorg.
Chem. 2002, 1367–1376.
Ltd. (Japan). This work was partially supported by the Russian
Foundation for Basic Research (Grant No. 03-03-32181) and Grant
of the President of RF for young scientists – doctors of sciences
(No. MD -21.2003.03).
[19] K. N. Gavrilov, Russ. J. Inorg. Chem. 1997, 42, 368–384.
[20] A. I. Polosukhin, O. G. Bondarev, S. E. Lyubimov, A. V. Koro-
stylev, K. A. Lyssenko, V. A. Davankov, K. N. Gavrilov, Tetra-
hedron: Asymmetry 2001, 12, 2197–2204.
[21] O. G. Bondarev, S. E. Lyubimov, A. A. Shiryaev, N. E. Kadilni-
kov, V. A. Davankov, K. N. Gavrilov, Tetrahedron: Asymmetry
2002, 13, 1587–1588.
[22] K. N. Gavrilov, V. N. Tsarev, A. A. Shiryaev, O. G. Bondarev,
S. E. Lyubimov, E. B. Benetsky, A. A. Korlykov, M. Yu. Anti-
pin, V. A. Davankov, H.-J. Gais, Eur. J. Inorg. Chem. 2004, 629–
634.
[23] A. J. Deeming, I. P. Rothwell, M. B. Hursthouse, K. M.
Abdul Malik, J. Chem. Soc., Dalton Trans. 1980, 1974–1982.
[24] A. D. Burrows, M. F. Mahon, M. Varrone, J. Chem. Soc., Dal-
ton Trans. 2003, 4718–4730.
[1] K. G. Moloy, J. L. Petersen, J. Am. Chem. Soc. 1995, 117,
7696–7710.
[2] S. Serron, S. P. Nolan, K. G. Moloy, Organometallics 1996, 15,
4301–4306.
[3] A. Huang, J. E. Marcone, K. L. Mason, W. J. Marshall, K. G.
Moloy, S. Serron, S. P. Nolan, Organometallics 1997, 16, 3377–
3380.
[4] A. M. Trzeciak, T. Glowiak, R. Grzybek, J. J. Ziolkowski, J.
Chem. Soc., Dalton Trans. 1997, 1831–1838.
[5] S. Serron, J. Huang, S. P. Nolan, Organometallics 1998, 17,
534–539.
[6] T. S. Barnard, M. R. Mason, Organometallics 2001, 20, 206–
214.
[7] A. D. Burrows, R. W. Harrington, M. F. Mahon, M. T. Palmer,
F. Senia, M. Varrone, J. Chem. Soc., Dalton Trans. 2003, 3717–
3726.
[25] J. A. McCleverty, G. Wilkinson, Inorg. Synth. 1966, 8, 211–214.
[26] P. R. Auburn, P. B. McKenzie, B. Bosnich, J. Am. Chem. Soc.
1985, 107, 2033–2046.
[8]
J. Castro, A. Moyano, M. A. Pericas, A. Riera, M. A. Maestro,
J. Mahia, Organometallics 2000, 19, 1704–1712.
[27] K. Moseley, P. M. Maitlis, J. Chem. Soc., Dalton Trans. 1974,
169–175.
[9] R. Jackstell, H. Klein, M. Beller, K.-D. Wiese, D. Rottger, Eur.
J. Org. Chem. 2001, 3871–3877.
[10] S. C. van der Slot, J. Duran, J. Luten, P. C. J. Kamer,
P. W. N. M. van Leeuwen, Organometallics 2002, 21, 3873–
3883.
[28] H. Yang, M. A. Khan, K. M. Nicholas, Organometallics 1993,
12, 3485–3494.
[29] H. Brunner, B. Habler, Z. Naturforsch., Teil B 1998, 53, 476–
480.
[30] H. Brunner, B. Reiter, G. Riepl, Chem. Ber. 1984, 117, 1330–
1354.
[11] E. E. Nifantyev, A. V. Shishin, A. T. Teleshev, A. R. Bekker,
N. N. Nevskii, N. N. Baturin, Russ. J. Gen. Chem. 1991, 61,
2481–2493.
[31] K. N. Gavrilov, O. G. Bondarev, R. V. Lebedev, A. I. Pol-
osukhin, A. A. Shiryaev, S. E. Lyubimov, P. V. Petrovskii, S. K.
Moiseev, V. N. Kalinin, N. S. Ikonnikov, V. A. Davankov, A. V.
Korostylev, J. Organomet. Chem. 2002, 655, 204–217.
[32] D. Seebach, E. Devaquet, A. Ernst, M. Hayakawa, F. N. M.
Kuhlne, W. B. Schweizer, B. Weber, Helv. Chim. Acta 1995, 78,
1636–1645.
[33] S. Breeden, M. Wills, J. Org. Chem. 1999, 64, 9735–9738.
[34] G. M. Sheldrick, SADABS, v.2.01, Bruker/Siemens Area De-
tector Absorption Correction Program, Bruker AXS, Madison,
Wisconsin, USA.
[12] P. S. Pregosin, R. W. Kunz, in: 31P NMR and 13C NMR of
Transition Metal Phosphine Complexes (in series NMR Basic
Principles and Progress), Springer Verlag: New York, 1979, p.
16.
[13] C. Reichardt, in: Solvents and Solvent Effects in Organic Chem-
istry; VCH Verlagsgesellschaft: Weinheim, 1988, p. 141.
[14] W. Simanko, K. Mereiter, R. Schmid, K. Kirchner, A. M.
Trzeciak, J. J. Ziolkowski, J. Organomet. Chem. 2000, 602, 59–
64.
[15] J. Ansell, M. Wills, Chem. Soc. Rev. 2002, 31, 259–268.
[16] O. Molt, T. Schrader, Synthesis 2002, 2633–2670.
[17] K. N. Gavrilov, O. G. Bondarev, A. I. Polosukhin, Russ. Chem.
Rev. 2004, 73, 671–700.
[35] G. M. Sheldrick, SHELXTL-97, V5.1, Bruker AXS Inc., Mad-
ison, WI 53719, USA, 1997.
Received: January 24, 2005
Published Online: July 6, 2005
Eur. J. Inorg. Chem. 2005, 3311–3319
www.eurjic.org
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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