Planar chiral P,O-compounds derived from ferrocenyl aryl ethers

Article abstract of DOI:10.1002/ejic.201000722

The ortho-directed lithiation of FcOC₆H₄-4-tBu (1) [Fc = (η⁵-C₅H₄)(η⁵-C ₅H₅)Fe] with nBuLi/tmeda is reported (tmeda = tetramethylethylenediamine). In this reaction, multimetalation occurs to yield novel 1,2-functionalized P,O-derivatives that contain up to four phosphanyl moieties as determined by NMR spectroscopic studies and single-crystal X-ray diffraction analysis. Thus available planar chiral P,O-ferrocenes can successfully be applied in the palladium-catalyzed Suzuki coupling of diverse aryl halides and aryl boronic acids. The aforementioned systems allow the activation of carbon-chlorine bonds in an efficient way and tolerate catalyst loadings as low as 10 ppm. Noteworthy is their remarkable ability to economically generate hindered biaryls under mild reaction conditions. Planar chiral P,O-ferrocenes are excellent ligands in the palladium-mediated C-C coupling of aryl halides and aryl boronic acids. They allow either the conversion ofunreactive substrates or reactions to be performed at low catalyst levels. Moreover, multiply ortho-substituted biaryls are accessible under mild conditions.

Full text of DOI:10.1002/ejic.201000722

FULL PAPER
DOI: 10.1002/ejic.201000722
Planar Chiral P,O-Compounds Derived from Ferrocenyl Aryl Ethers
Dieter Schaarschmidt[a] and Heinrich Lang*[a]
Dedicated to Professor Wolfgang Kläui on the occasion of his 65th birthday
Keywords: Ferrocenes / C–C coupling / Planar chirality / Phosphanes / Metalation
The ortho-directed lithiation of FcOC6H4-4-tBu (1) [Fc = (η5-
C5H4)(η5-C5H5)Fe] with nBuLi/tmeda is reported (tmeda =
tetramethylethylenediamine). In this reaction, multimet-
alation occurs to yield novel 1,2-functionalized P,O-deriva-
tives that contain up to four phosphanyl moieties as deter-
mined by NMR spectroscopic studies and single-crystal X-
ray diffraction analysis. Thus available planar chiral P,O-fer-
rocenes can successfully be applied in the palladium-cata-
lyzed Suzuki coupling of diverse aryl halides and aryl bor-
onic acids. The aforementioned systems allow the activation
of carbon–chlorine bonds in an efficient way and tolerate cat-
alyst loadings as low as 10 ppm. Noteworthy is their remark-
able ability to economically generate hindered biaryls under
mild reaction conditions.
surprise, this class of organometallics has not been studied
further yet.
This prompted us to examine the ortho-directed met-
alation of ferrocenyl aryl ethers. Thus available hemilabile
P,O-compounds can be considered to be promising ligands
in a palladium-catalyzed Suzuki reaction (Figure 1).[9]
Introduction
Ferrocene-based phosphanes have widely been applied as
donor ligands both in organometallic chemistry and in
homogeneous catalysis.[1] Among this family of compounds
planar chiral ferrocenylphosphanes, such as Josiphos and
trans-chelating bisphosphane ligands (TRAPs), are of par-
ticular interest in asymmetric synthesis and catalysis.[2] To
date, the most prominent synthesis methodology utilizes the
diastereoselective ortho-directed metalation of chiral ferro-
cenes and is strongly affiliated with the pioneering work of
Ugi, Togni, Hayashi et al.[3]
Figure 1. Concept of a hemilabile P,O compound.
Ortho-metalation was independently described by Wit-
tig[4] and Gilman[5] in the late 1930s in the example of the
deprotonation of anisole by nBuLi. However, to the best of
our knowledge, alkoxy or aryloxy ferrocenes have never
been applied in such reactions. So far, the synthesis of such
molecules relies on the etherification of hydroxyferrocene
FcOH [Fc = (η5-C5H4)(η5-C5H5)Fe] as demonstrated by
Nesmejanow et al.[6] For the synthesis of ferrocenyl aryl
ethers, Rausch exerted the Ullmann coupling of haloferro-
cenes with alkaline phenolates in the presence of copper,
however, which afforded several byproducts.[7] Recently,
Plenio and co-workers reported a straightforward cop-
per(I)-catalyzed synthesis of diverse ferrocenyl aryl ethers
starting from iodoferrocene and various phenols.[8] To our
Results and Discussion
The most commonly used synthesis protocol for ortho-
directed metalations utilizes lithium diisopropylamide
(LDA) or BuLi in tetrahydrofuran or diethyl ether at low
temperature.[10] However, in the case of ferrocene
FcOC6H4-4-tBu (1) [Fc = (η5-C5H4)(η5-C5H5)Fe], no met-
alation occurs within hours under similar reaction condi-
tions even in the presence of tetramethylethylenediamine
(tmeda). Running the reaction at ambient temperature
along with a change of the solvent to n-hexane resulted in
a 90% conversion of 1 within twelve hours. Successful con-
version of the lithiated species to the corresponding ferro-
cenylphosphanes was possible by addition of ClPPh2 (2a)
at –78 °C (Scheme 1). After appropriate workup, we were
astonished to isolate three products, 3a, 4a, and 5a, of
which 3a is clearly dominating. The substitution pattern of
3a–5a is in accordance with ortho-directed metalation at the
cyclopentadienyl and the aryl moiety.
[a] Technische Universität Chemnitz, Fakultät für
Naturwissenschaften,
Institut für Chemie, Lehrstuhl für Anorganische Chemie,
Straße der Nationen 62, 09111 Chemnitz, Germany
Fax: +49-371-531-21219
E-mail: heinrich.lang@chemie.tu-chemnitz.de
Supporting information for this article is available on the
WWW under http://dx.doi.org/10.1002/ejic.201000722.
View this journal online at
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D. Schaarschmidt, H. Lang
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Scheme 1. Synthesis of 3a–6a. (a) 1. nBuLi, tmeda, n-hexane, 25 °C,
12 h; 2. ClPPh2 (2a), –78 °C, 1 h.
Scheme 2. Synthesis of 3a–3c. (a) 1. nBuLi, tmeda, n-hexane, 25 °C,
12 h; 2. ClPR2 (2), tetrahydrofuran, –78 °C, 1 h (3a: 64%; 3b: 55%).
(b) 1. nBuLi, tmeda, n-hexane, 25 °C, 12 h; 2. nBu3SnCl, tetra-
hydrofuran, –78 °C, 1 h (23%). (c) 1. nBuLi, tetrahydrofuran,
–78 °C, 1 h; 2. ClPCy2 (2c), tetrahydrofuran, –78 °C, 1 h (91%).
Attempts to prepare 4a and 5a in a more efficient way
prompted us to use nBuLi/tmeda in excess amounts. Chang-
ing the molar ratio of 1/nBuLi from 1:1 to 1:2 resulted in
the selective formation of 4a as frequently observed in fer-
rocene chemistry.[11] However, with a ratio of 1:5 only 5a
and 6a, respectively, could be obtained after column
4
chromatography, thus proving multimetalation of 1. Such [3J(H,H) = 2.6 Hz and J(H,H) = 1.5 Hz] and one pseu-
dilithiation processes at one cyclopentadienyl ligand were dotriplet [3J(H,H) = 2.6 Hz] are observed (Figure 2). The
recently observed by several groups.[12] It must be emphas- 1,2-P,O-substitution is further confirmed by the J(C,P) cou-
ized that 5a and 6a could only be isolated on a milligram pling constants of C1, the carbon atom that bears the aryl-
scale. Further products could not be identified, which oxy functionality. The values vary between 15 and 20 Hz,
2
points to significant decomposition of the multimetalated which can be considered typical for J(C,P) constants. Sim-
species.
ilar coupling J(C,P) constants [15 (5a), 17 Hz (6a)] are
The synthesis methodology for the preparation of 3a found for the corresponding iC atom of the benzene moiety.
could successfully be transferred to ClPoTol2 (Tol = tolyl; Additional proof for 1,2-P,O-substitution also comes from
2b) as outlined in Scheme 2. Desired product 3b could be the coupling pattern and chemical shifts of the three re-
separated from the multiple substituted side products by maining aryloxy hydrogen atoms (Figure 2).
column chromatography. In the case of the alkylphosphane
The second cyclopentadienyl ring shows resonance sig-
ClPCy2 (Cy = cC6H11) (2c), this separation failed. Analyti- nals characteristic for non-, mono-, and disubstitution. The
cal pure 3c could neither be obtained by column 1,2-P,P-substitution is verified by J(H,H), J(C,P), and
chromatography nor crystallization.[13] Therefore we devel- J(P,P) constants, of which the latter is 97 Hz.[16] This cou-
oped another synthesis route that utilized organometallic 7 pling constant is very impressive as only a few ferrocene
(Scheme 2). Transmetalation of dark red 7 with nBuLi and compounds with J(P,P) are described [i.e. 75 Hz in 2-(di-
subsequent treatment with 2c afforded the desired orange phenylphosphanyl)-1-(dicyclohexylphosphanyl)ferrocene].[17]
3c in almost quantitative yield and in analytical pure form. In addition, ferrocenes 5a and 6a exhibit a through-space
Replacement of the nonchiral base tmeda by the chiral rather than scalar coupling of 5 and 7 Hz between P1 and
alkaloid (–)-sparteine induces[14] 37–40% enantiomeric ex- P3 (Figure 3).
cess (ee) in 3a.[15]
The molecular structures of 3a, 4a, and 5a predicted by
All ferrocenes synthesized are pale orange solids that dis- NMR spectroscopy (vide supra) were additionally con-
solve in common organic solvents. Ferrocenes 3a–3c are firmed by single-crystal X-ray diffraction analyses. Due to
stable in air both in the solid state and in solution.
the poor crystallization behavior of 3a and 5a, we converted
Identification of compounds 3a–3c, 4a, 5a, 6a, and 7 de- these compounds with elemental selenium to the respective
scribed herein was deduced from their spectroscopic data selenophosphanes 3a-Se and 5a-Se3. Graphical representa-
(IR, NMR 1H, 13C{1H}, 31P{1H}) and the structures of 3a, tions are given in Figures 4 (3a-Se), 5 (4a), and 6 (5a-Se3).
4a, and 5a were confirmed by single-crystal X-ray diffrac- Selected bond lengths [Å] and angles [°] are listed in the
tion analysis. Correct elemental microanalyses were ob- captions of these figures. The crystal and structure refine-
tained. As expected, IR studies are less informative, whereas ment data for all ferrocenes are summarized in Table 4 in
NMR spectroscopy is most capable of unambiguously de- the Exp. Section.
termining the identity of the ferrocenes.
The palladium-catalyzed Suzuki reaction, the carbon–
Typical of all compounds is the 1,2-substitution pattern carbon cross-coupling of aryl and vinyl halides/triflates
of the oxygen-bearing cyclopentadienyl rings, which is evi- with boronic acids, is among the most essential transforma-
denced from the J(H,H) and J(C,P) coupling constants. In tions in organic and organometallic chemistry[18] and has
1
the H{31P} NMR spectra of 3–6 two doublets-of-doublets been applied industrially for the production of fine chemi-
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Planar Chiral P,O-Compounds
1
Figure 2. Parts of the H NMR spectra of 1 and 3a–6a between δ = 6–8 ppm (top) and δ = 3–4.5 ppm (bottom) with the signal shape of
1
1
3-H, 4-H, and 5-H of 3a from the H{31P} NMR spectra, and a part of the H{31P} NMR spectra of 5a that shows protons 3-H, 5-H,
and 6-H (CDCl3, 25 °C).
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As generally accepted in literature, hybrid P,O ligands are
superior over monophosphane or diphosphane ligands in
the Suzuki reaction.[9] This is why we applied phosphanes
3a–3c in the coupling of different aryl halides with diverse
boronic acids (see Tables 1, 2, and 3).
Excellent catalysts (i) are able to activate aryl chlorides
independently of their electronic properties, (ii) can couple
substrates at very low catalyst loadings, and (iii) are able to
prepare sterically hindered biaryls (iv) under mild reaction
conditions.
As shown in Table 1, strongly basic 3c is able to couple
activated (entry 1), non- (entries 2–4), and deactivated (entries
5–7) aryl chlorides with different boronic acids. Coupling of
ortho-functionalized substrates is also possible (entries 2, 4,
and 7). Unfortunately, the catalyst loadings cannot be de-
creased without significant loss of activity (entry 8).[24]
When it comes to the commercial application of coupling
reactions, the costs of the noble-metal catalysts have to be
considered. We studied the influence of lowering the cata-
lyst concentration in the coupling of 2-bromotoluene
(Table 2, entries 1–4) and 4Ј-chloroacetophenone (entries 5
and 6) with phenylboronic acid. It was found that quantita-
tive yields of the appropriate coupling products can only be
achieved for the synthesis of 2-methylbiphenyl at 0.1 and
0.01 mol-% (entries 1 and 2), otherwise the yields are be-
tween 31 and 85%. Furthermore, the results show that for
the conversion of 2-bromotoluene the catalyst loading can
be reduced to 0.001 mol-% (δ = 10 ppm, entry 4) with a
turnover number (TON) Ͼ 30000 and turnover frequency
(TOF) Ͼ 1000 h–1. In the case of less active 4Ј-chloroaceto-
Figure 3. Part of the 31P{1H} NMR spectra of 3a–6a between δ =
–30 and –10 ppm (CDCl3, 25 °C).
cals and pharmaceuticals.[19–21] Recently, very active orga- phenone, the presented strategy is less successful. Catalyst
nometallic and metal–organic systems for a wide variety of concentrations lower than 0.01 mol-% cannot be reached
applications have been presented.[22,23]
effectively.
Figure 4. ORTEP diagram (50% probability level) of 3a-Se with atom numbering scheme. The hydrogen atoms are omitted for clarity.
Selected bond lengths [Å] and angles [°]: D1–Fe1 1.6516(3), D2–Fe1 1.6560(3), C1–O1 1.370(2), C2–P1 1.806(2), P1–Se1 2.1101(5); D1–
Fe1–D2 177.57(2), O1–C1–C2–P1 2.4(3), C1–D1–D2–C6 9.3(1) (D1 = centroid C1–C5, D2 = centroid C6–C10). The figure in parentheses
after each calculated value represents the standard deviation in units of the last significant digits.
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Planar Chiral P,O-Compounds
Figure 5. ORTEP diagram (50% probability level) of 4a with atom numbering scheme. The hydrogen atoms are omitted for clarity.
Selected bond lengths [Å] and angles [°]: D1–Fe1 1.6376(3), D2–Fe1 1.6447(3), C1–O1 1.377(3), C2–P1 1.830(2), C6–P2 1.821(2); D1–
Fe1–D2 177.74(2), O1–C1–C2–P1 2.3(3), C1–D1–D2–C8 17.5(2), P1–D1–D2–P2 131.03(2) (D1 = centroid C1–C5, D2 = centroid C6–
C10). The figure in parentheses after each calculated value represents the standard deviation in units of the last significant digits.
The ability to synthesize sterically hindered biaryls by Su-
zuki coupling is still a challenge. Reaction protocols that
can convert hindered substrates under mild conditions are
of great interest and could provide convenient access to ax-
ial-chiral biaryls.[25] As can be seen from Table 3, biaryls
with up to three ortho substituents (entries 3 and 5) are
accessible in excellent yields at 50 °C and 0.1 mol% [Pd].
Even the highly hindered 2,4,6-triisopropylbromobenzene
can be coupled smoothly (entry 7). Attempts to utilize or-
tho-disubstituted boronic acids for the synthesis of tetra-
functionalized biphenyls were not satisfactory so far as the
catalyst is clearly very sensitive towards steric hindrance at
the boronic acid.
Recapitulating the aforementioned results, only strongly
Lewis basic 3c in combination with [Pd2(dba)3] can success-
fully be applied in the catalytic coupling of chloroarenes
with boronic acids. It was found that less basic 3b is highly
sensitive towards the activation of carbon–halide bonds. Al-
though nonactivated bromoarenes are coupled smoothly,
significant loss of activity is observed when deactivated bro-
moarenes or activated aryl chlorides are used.[26] These re-
sults are in accordance with similar systems described in
literature that show that the catalytic behavior towards
chloroarenes strongly corresponds to the electron richness
of the phosphane ligands.[27] However, less-electron-rich di-
arylphosphanes such as 3a and 3b are beneficial for homo-
geneous catalysis as well. We were able to demonstrate that
3a can be applied to the coupling of bromoarenes with bo-
Figure 6. ORTEP diagram (50% probability level) of 5a-Se3 with
ronic acids at very low catalyst levels and that 3b is remark-
atom numbering scheme. The hydrogen atoms are omitted for clar-
ably qualified for the synthesis of sterically hindered bi-
ity. Selected bond lengths [Å] and angles [°]: D1–Fe1 1.6517(11),
D2–Fe1 1.6554(11), C1–O1 1.391(9), C2–P1 1.813(8), C6–P2
aryls.[28]
1.801(7), C12–P3 1.825(7), P1–Se1 2.110(2), P2–Se2 2.105(2), P3–
Se3 2.110(2); D1–Fe1–D2 177.27(8), O1–C1–C2–P1 3.6(12), C1–
D1–D2–C8 7.8(6), P1–D1–D2–P2 148.50(5) (D1 = centroid C1–
C5, D2 = centroid C6–C10). The figure in parentheses after each
calculated value represents the standard deviation in units of the
last significant digits.
The application of enantiomerically enriched 3a (vide su-
pra) in an asymmetric Suzuki coupling has been so far un-
successful,[29] presumably due to the low enantiomeric ex-
cess of the planar chiral phosphane or a negative nonlinear
effect.[30]
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D. Schaarschmidt, H. Lang
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Table 1. Suzuki coupling of aryl chlorides.[a]
[a] Reaction conditions: aryl chloride (1.0 equiv.), boronic acid (1.5 equiv.), K3PO4 (3.0 equiv.), toluene (2 mLmmol–1 halide), [Pd2(dba)3]/
3c (dba = dibenzylideneacetone), 1.0 mol-% [Pd], 100 °C, 24 h. Reaction times were not minimized. [b] NMR spectroscopic yields based
upon an average of two runs. [c] 0.1 mol-% [Pd].
Table 2. Suzuki coupling at low catalyst loadings.[a]
[a] Reaction conditions: aryl halide (1.0 equiv.), boronic acid (1.5 equiv.), K3PO4 (3.0 equiv.), toluene (2 mLmmol–1 halide), [Pd2(dba)3]/
3a, 100 °C, 24 h. Reaction times were not minimized. [b] NMR spectroscopic yields based upon an average of two runs.
P,O-Ferrocenes
Fe(η5-C5H5)[η5-C5H3(OC6H4-4-tBu-
Conclusion
C6H4)-2-PR2] [R = Ph (3a), oTol (3b), Cy (3c)] were success-
fully applied in the palladium-catalyzed Suzuki cross-cou-
pling of diverse aryl halides with aryl boronic acids. Solely
3c allows the activation of carbon–chlorine bonds indepen-
dently of the electronic properties of the aryl chlorides in
an efficient way. Less Lewis basic phosphanes 3a and 3b,
however, can be exerted for (i) coupling reactions at low
catalyst levels, and (ii) the synthesis of sterically hindered
biaryls. The catalyst system 3a/[Pd2(dba)3] tolerates load-
ings as low as 10 ppm in the synthesis of 2-methylbiphenyl
(TON Ͼ 30 000; TOF Ͼ 1 000 h–1). For the coupling of
ortho-functionalized arenes, the couple 3b/[Pd2(dba)3] has
turned out to be a remarkably efficient system. At mild re-
action conditions (50 °C, 0.1 mol-% [Pd]) biaryls with up to
Within this study the straightforward synthesis methodol-
ogy for planar chiral 1,2-functionalized P,O-ferrocenes has
been developed. Starting from FcOC6H4-4-tBu (1) [Fc =
Fe(η5-C5H4)(η5-C5H5)], the ability of ferrocenyl aryl ethers
to undergo ortho-directed lithiation was proven for the first
time. Surprisingly, besides the monophosphanes, which
could be isolated as dominating products (yields up to
64%), other ferrocenes with up to four phosphanyl moieties
are formed as side products, thereby indicating multimet-
alation processes. The substitution pattern of the phos-
phanes obtained is associated with the ortho-directing effect
of the ether functionality, as confirmed by NMR spec-
troscopy and single-crystal X-ray diffraction analysis.
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Planar Chiral P,O-Compounds
Table 3. Suzuki coupling of sterically hindered substrates.[a]
[a] Reaction conditions: aryl chloride (1.0 equiv.), boronic acid (1.5 equiv.), K3PO4 (3.0 equiv.), toluene (2 mLmmol–1 halide), [Pd2(dba)3]/
3b, 0.1 mol% [Pd], 50 °C, 24 h. Reaction times were not minimized. [b] NMR spectroscopic yields based upon an average of two runs.
[c] 2.0 equiv. boronic acid, 100 °C. [d] 0.5 mol-% [Pd].
added in a single portion, stirred for 30 min at –78 °C and then for
90 min at ambient temperature. The reaction mixture was diluted
with water (50 mL) and extracted with diethyl ether (3ϫ50 mL).
The combined organic extracts were dried with MgSO4 and con-
centrated under reduced pressure. The crude material obtained was
purified by column chromatography on alumina [n-hexane/diethyl
ether = 95:5 (v/v)]. Ferrocene 3a was isolated as an orange solid
(0.50 g, 0.96 mmol, 64% based on 1); m.p. 96–98 °C. 1H NMR
(500 MHz, CDCl3, 25 °C, TMS): δ = 1.25 [s, 9 H, C(CH3)3], 3.66–
3.68 (m, 1 H, 3-H/C5H3), 4.05 [pt, 3J(H,H) = 2.6 Hz, 1 H, 4-H/
C5H3], 4.15 (s, 5 H, C5H5), 4.38–4.40 (m, 1 H, 5-H/C5H3), 6.81–
6.84 (m, 2 H, o-C6H4), 7.11–7.15 (m, 2 H, m-C6H4), 7.18–7.22 (m,
3 H, C6H5), 7.27–7.32 (m, 2 H, C6H5), 7.34–7.38 (m, 3 H, C6H5),
three ortho substituents are accessible in excellent yields.
Even the highly hindered 2,4,6-triisopropylbromobenzene
can be coupled smoothly.
Experimental Section
rac-1-(4-tert-Butylphenoxy)-2-(diphenylphosphanyl)ferrocene (3a):
nBuLi (2.5  in n-hexane, 0.6 mL, 1.5 mmol, 1.0 equiv.) was added
dropwise over 5 min to a solution of 1 (0.50 g, 1.5 mmol) and
tmeda (0.22 mL, 1.5 mmol, 1.0 equiv.) in anhydrous n-hexane
(30 mL). The mixture was stirred for 12 h at ambient temperature.
After cooling to –78 °C, neat 2a (0.33 g, 1.5 mmol, 1.0 equiv.) was
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D. Schaarschmidt, H. Lang
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7.55–7.60 (m, 2 H, C6H5) ppm. 13C{1H} NMR (125.7 MHz,
CDCl3, 25 °C, TMS): δ = 31.4 [s, 3 C, C(CH3)3], 34.0 [s, 1 C,
C(CH3)3], 61.9 (s, 1 C, 5-C/C5H3), 64.0 (s, 1 C, 4-C/C5H3), 66.5 (s,
134 °C. H NMR (500 MHz, CDCl3, 25 °C, TMS): δ = 1.32 [s, 9
H, C(CH3)3], 1.11–1.35 (m, 10 H, C6H11), 1.57–2.10 (m, 12 H,
C6H11), 3.94–3.96 (m, 1 H, 3-H/C5H3), 3.99 [pt, 3J(H,H) = 2.6 Hz,
1 H, 4-H/C5H3], 4.21 (s, 5 H, C5H5), 4.25–4.26 (m, 1 H, 5-H/C5H3),
6.97–7.01 (m, 2 H, o-C6H4), 7.28–7.32 (m, 2 H, m-C6H4) ppm.
13C{1H} NMR (125.7 MHz, CDCl3, 25 °C, TMS): δ = 26.42 [d,
1
1
1 C, 3-C/C5H3), 67.3 [d, J(C,P) = 9.7 Hz, 1 C, 2-C/C5H3], 70.2 (s,
5 C, C5H5), 117.2 (s, 2 C, o-C6H4), 125.7 (s, 2 C, m-C6H4), 126.6
2
3
[d, J(C,P) = 18.6 Hz, 1 C, 1-C/C5H3], 127.8 [d, J(C,P) = 6.5 Hz,
3
4
2 C, m-C6H5], 127.9 (s, 1 C, p-C6H5), 128.0 [d, J(C,P) = 7.4 Hz, 2
C, m-C6H5], 128.7 (s, 1 C, p-C6H5), 132.8 [d, J(C,P) = 19.5 Hz, 2
4J(C,P) = 1.0 Hz, 1 C, 4-C/C6H11], 26.45 [d, J(C,P) = 0.9 Hz, 1 C,
2
4-C/C6H11], 27.30 [d, J(C,P) = 10.4 Hz, 1 C, C6H11], 27.39 [d,
C, o-C6H5], 134.5 [d, 2J(C,P) = 20.8 Hz, 2 C, o-C6H5], 137.4 [d, J(C,P) = 9.3 Hz, 1 C, C6H11], 27.47 [d, J(C,P) = 8.3 Hz, 1 C,
1J(C,P) = 9.1 Hz, 1 C, i-C6H5], 138.9 [d, J(C,P) = 10.8 Hz, 1 C, i-
C6H11], 27.48 [d, J(C,P) = 10.4 Hz, 1 C, C6H11], 30.0 [d, J(C,P) =
1
C6H5], 145.1 (s, 1 C, p-C6H4), 155.9 (s, 1 C, i-C6H4) ppm. 31P{1H} 13.1 Hz, 1 C, C6H11], 30.7 [d, J(C,P) = 12.8 Hz, 1 C, C6H11], 31.1
NMR (202.5 MHz, CDCl3, 25 °C, H3PO4): δ = –24.3 (s) ppm. IR [d, J(C,P) = 9.7 Hz, 1 C, C6H11], 31.2 [d, J(C,P) = 10.6 Hz, 1 C,
(KBr): ν = 3099, 3066 (=C–H), 2960, 2867 (CH ), 1508 (C=C), C6H11], 31.5 [s, 3 C, C(CH3)3], 33.54 [d, J(C,P) = 11.3 Hz, 1 C, 1-
1
˜
3
1
1372, 1362 [C(CH3)3], 1245 (=C–O–C), 828, 813, 747, 739, 696
(=C–H) cm–1. C32H31FeOP (518.41): calcd. C 74.14, H 6.03; found
C 74.06, H 6.26.
C/C6H11], 33.55 [d, J(C,P) = 11.5 Hz, 1 C, 1-C/C6H11], 34.2 [s, 1
3
C, C(CH3)3], 60.4 (s, 1 C, 5-C/C5H3), 62.9 [d, J(C,P) = 2.7 Hz, 1
1
C, 4-C/C5H3], 66.5 [d, J(C,P) = 21.2 Hz, 1 C, 2-C/C5H3], 67.0 [d,
3J(C,P) = 11.2 Hz, 1 C, 3-C/C5H3], 70.2 (s, 5 C, C5H5), 117.5 (s, 2
rac-1-(4-tert-Butylphenoxy)-2-[bis(2-tolyl)phosphanyl]ferrocene (3b):
Same procedure as described for 3a but 2b (0.37 g, 1.5 mmol,
1.0 equiv.) was used instead of 2a. The product was purified by
column chromatography on alumina [n-hexane/diethyl ether = 95:5
(v/v)] and 3b was isolated as an orange solid (0.45 g, 0.82 mmol,
2
C, o-C6H4), 125.4 [d, J(C,P) = 6.4 Hz, 1 C, 1-C/C5H3], 126.0 (s, 2
C, m-C6H4), 145.5 (s, 1 C, p-C6H4), 155.6 (s, 1 C, i-C6H4) ppm.
31P{1H} NMR (202.5 MHz, CDCl3, 25 °C, H3PO4): δ = –8.6 (s)
ppm. IR (KBr): ν = 3097, 3055 (=C–H), 2955, 2871 (CH ), 2919,
˜
3
2848 (CH2), 1509 (C=C), 1376, 1362 [C(CH3)3], 1238 (=C–O–C),
834, 817 (=C–H) cm–1. HRMS: m/z: calcd. for C32H43FeOP:
531.2474; found 531.2374 [M + H]+. C32H43FeOP (530.50): calcd.
C 72.45, H 8.17; found C 71.60, H 8.02.
1
55% based on 1); m.p. 119–122 °C. H NMR (500 MHz, CDCl3,
25 °C, TMS): δ = 1.30 [s, 9 H, C(CH3)3], 2.21 [d, 4J(P,H) = 1.6 Hz,
3 H, C6H4CH3], 2.91 (s, 3 H, C6H4CH3), 3.76–3.78 (m, 1 H, 3-H/
C5H3), 4.08 [dpt, 3J(H,H) = 2.6, 4J(P,H) = 0.5 Hz, 1 H, 4-H/C5H3],
4.15 (s, 5 H, C5H5), 4.39–4.41 (m, 1 H, 5-H/C5H3), 6.96–7.00 [m,
2 H, o-C6H4OC(CH3)3], 7.00–7.15 (m, 4 H, C6H4CH3), 7.16–7.20
(m, 1 H, C6H4CH3), 7.22–7.32 [m, 5 H, C6H4CH3 and m-
C6H4OC(CH3)3] ppm. 13C{1H} NMR (125.7 MHz, CDCl3, 25 °C,
TMS): δ = 20.8 [d, 3J(C,P) = 20.3 Hz, 1 C, C6H4CH3], 22.0 [d,
3J(C,P) = 24.3 Hz, 1 C, C6H4CH3], 31.5 [s, 3 C, C(CH3)3], 34.2 [s,
rac-1-(4-tert-Butylphenoxy)-2,1Ј-bis(diphenylphosphanyl)ferrocene
(4a): nBuLi (2.5  in n-hexane, 1.2 mL, 3.0 mmol, 2.0 equiv.) was
added dropwise over 5 min to a solution of 1 (0.50 g, 1.5 mmol)
and tmeda (0.45 mL, 3.0 mmol, 2.0 equiv.) in anhydrous n-hexane
(30 mL). The mixture was stirred for 12 h at ambient temperature.
After cooling to –78 °C, neat 2a (0.66 g, 3.0 mmol, 2.0 equiv.) was
added in a single portion, and the reaction was stirred for 30 min
at –78 °C and then for 90 min at ambient temperature. The reaction
mixture was diluted with water (50 mL) and extracted with diethyl
ether (3ϫ50 mL). The combined organic extracts were dried with
MgSO4 and concentrated under reduced pressure. The crude mate-
rial obtained was purified by column chromatography on alumina
[n-hexane/diethyl ether = 90:10 (v/v)]. Compound 4a was isolated
as a yellow solid (0.70 g, 1.00 mmol, 67% based on 1). Single crys-
tals of 4a could be obtained by recrystallization from CHCl3; m.p.
186–188 °C. 1H NMR (500 MHz, CDCl3, 25 °C, TMS): δ = 1.26
[s, 9 H, C(CH3)3], 3.50–3.53 (m, 1 H, 3-H/C5H3), 3.77–3.81 (m, 1
H, Hα-C5H4), 3.91 [pt, 3J(H,H) = 2.5 Hz, 1 H, 4-H/C5H3], 4.26–
4.30 (m, 1 H, Hα-C5H4), 4.32–4.37 (m, 2 H, 5-H/C5H3 and Hβ-
C5H4), 4.48–4.53 (m, 1 H, Hβ-C5H4), 6.78–6.83 (m, 2 H, o-C6H4),
7.11–7.16 (m, 2 H, m-C6H4), 7.17–7.22 (m, 3 H, C6H5), 7.22–7.36
(m, 15 H, C6H5), 7.48–7.53 (m, 2 H, C6H5) ppm. 13C{1H} NMR
(125.7 MHz, CDCl3, 25 °C, TMS): δ = 31.4 [s, 3 C, C(CH3)3], 34.1
[s, 1 C, C(CH3)3], 63.6 (s, 1 C, 5-C/C5H3), 66.2 [d, 3J(C,P) = 1.7 Hz,
1 C, 4-C/C5H3], 67.4 (s, 1 C, 3-C/C5H3), 67.9 [d, 1J(C,P) = 10.9 Hz,
3
1 C, C(CH3)3], 61.3 [d, J(C,P) = 2.0 Hz, 1 C, 5-C/C5H3], 63.9 (s,
1
1 C, 4-C/C5H3), 66.2 [d, J(C,P) = 9.4 Hz, 1 C, 2-C/C5H3], 66.8 (s,
1 C; 3-C/C5H3), 70.0 (s, 5 C, C5H5), 118.3 (s, 2 C, o-C6H4), 125.2
(s, 1 C, C6H4CH3), 125.5 [d, J(C,P) = 1.3 Hz, 1 C, C6H4CH3], 125.9
(s, 2 C, m-C6H4), 127.7 (s, 1 C, C6H4CH3), 127.8 [d, 2J(C,P) =
18.9 Hz, 1 C, 1-C/C5H3], 129.0 (s, 1 C, C6H4CH3), 129.7 [d, 3J(C,P)
= 4.3 Hz, 1 C, 6-C/C6H4CH3], 129.9 [d, J(C,P) = 5.7 Hz, 1 C, 6-
C/C6H4CH3], 131.6 (s, 1 C, C6H4CH3), 134.8 [d, J(C,P) = 9.2 Hz,
3
1
1
1 C, 2-C/C6H4CH3], 135.7 (s, 1 C, C6H4CH3), 138.8 [d, J(C,P) =
2
13.5 Hz, 1 C, 2-C/C6H4CH3], 140.6 [d, J(C,P) = 25.6 Hz, 1 C, 1-
C/C6H4CH3], 143.2 [d, 2J(C,P) = 29.2 Hz, 1 C, 1-C/C6H4CH3],
145.7 (s, 1 C, p-C6H4), 155.6 (s, 1 C, i-C6H4) ppm. 31P{1H} NMR
(202.5 MHz, CDCl3, 25 °C, H3PO4): δ = –44.0 (s) ppm. IR (KBr):
ν = 3098, 3058, 3003 (=C–H), 2960, 2864 (CH ), 1509 (C=C), 1373,
˜
3
1362 [C(CH3)3], 1242 (=C–O–C), 837, 818, 802, 750 (=C–H) cm–1.
HRMS: m/z: calcd. for C34H35FeOP: 546.1770; found 546.1684
[M]+. C34H35FeOP (546.46): calcd. C 74.73, H 6.46; found C 74.28,
H 6.66.
rac-1-(4-tert-Butylphenoxy)-2-(dicyclohexylphosphanyl)ferrocene
(3c): A solution of 7 (0.21 g, 0.34 mmol) in anhydrous tetra-
hydrofuran (10 mL) was cooled to –78 °C and nBuLi (2.5  in n-
hexane, 0.13 mL, 0.34 mmol, 1.0 equiv.) was added slowly. The
mixture was stirred for 30 min at –78 °C. Afterwards, neat 2c
(0.08 g, 0.34 mmol, 1.0 equiv.) was added in a single portion. The
reaction was stirred for 30 min at –78 °C and 90 min at ambient
2
1 C, 2-C/C5H3], 73.6 [d, J(C,P) = 11.4 Hz, 1 C, o-C5H4], 74.0 (m,
1 C, m-C5H4), 74.7 [d, 3J(C,P) = 4.2 Hz, 1 C, m-C5H4], 75.4 [d,
1
2J(C,P) = 17.9 Hz, 1 C, o-C5H4], 77.3 [d, J(C,P) = 8.3 Hz, 1 C, i-
C5H4], 117.3 (s, 2 C, o-C6H4), 125.8 (s, 2 C, m-C6H4), 126.8 [d,
2J(C,P) = 18.4 Hz, 1 C, 1-C/C5H3], 127.9 [d, 3J(C,P) = 6.7 Hz, 2 C,
m-C6H5], 128.0 [d, 3J(C,P) = 7.3 Hz, 2 C, m-C6H5], 128.0–128.1
temperature. After addition of water (50 mL) the organic layer was (m, 5 C, m-C6H5 and p-C6H5), 128.3 (s, 1 C, p-C6H5), 128.5 (s, 1
2
separated and the aqueous phase was extracted with diethyl ether
(3ϫ50 mL). The combined organic phases were dried with MgSO4
and concentrated under reduced pressure. The crude material ob-
tained was purified by column chromatography on alumina [n-hex-
ane/diethyl ether = 95:5 (v/v)]. Compound 3c was isolated as an
orange solid (0.16 g, 0.31 mmol, 91 % based on 7); m.p. 132–
C, p-C6H5), 128.9 (s, 1 C, p-C6H5), 132.9 [d, J(C,P) = 19.3 Hz, 2
C, o-C6H5], 133.1 [d, 2J(C,P) = 19.1 Hz, 2 C, o-C6H5], 133.6 [d,
2J(C,P) = 19.9 Hz, 2 C, o-C6H5], 134.5 [d, J(C,P) = 20.9 Hz, 2 C,
2
o-C6H5], 137.1 [d, 1J(C,P) = 9.0 Hz, 1 C, i-C6H5], 138.7 [d, 1J(C,P)
1
= 9.9 Hz, 1 C, i-C6H5], 138.8 [d, J(C,P) = 10.7 Hz, 1 C, i-C6H5],
139.2 [d, J(C,P) = 10.0 Hz, 1 C, i-C6H5], 145.4 (s, 1 C, p-C6H4),
1
4818
www.eurjic.org
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2010, 4811–4821

Planar Chiral P,O-Compounds
155.8 (s, 1 C, i-C6H4) ppm. 31P{1H} NMR (202.5 MHz, CDCl3,
28.5 Hz, 1J(C,P) = 8.6 Hz, 1 C, 1-C or 2-C/C5H3P2], 113.8 [d,
25 °C, H3PO4): δ = –17.8 (s, 1 P, C5H4P), –24.3 (s, 1 P, C5H3P) 3J(C,P) = 1.1 Hz, 1 C, 6-C/C6H3], 124.9 [d, 2J(C,P) = 15.0 Hz, 1 C,
1
ppm. IR (KBr): ν = 3066, 3044, 3026 (=C–H), 2964, 2950, 2900,
1-C/C5H3OP], 125.8 [d, J(C,P) = 15.5 Hz, 1 C, 2-C/C6H3], 125.9
(s, 1 C, 5-C/C6H3), 127.5–128.8 (m, 24 C, m-C6H5 and p-C6H5),
˜
2864 (CH3), 1509 (C=C), 1361 [C(CH3)3], 1242 (=C–O–C), 826,
742, 698 (=C–H) cm–1. C44H40FeOP2 (702.58): calcd. C 75.22, H 130.3 (s, 1 C, 3-C/C6H3), 132.6 [d, 2J(C,P) = 19.0 Hz, 2 C, o-C6H5],
5.74; found C 75.10, H 5.90.
133.0 [d, 2J(C,P) = 19.4 Hz, 2 C, o-C6H5], 133.3 [d, 2J(C,P) =
2
20.6 Hz, 2 C, o-C6H5], 133.8 [d, J(C,P) = 21.5 Hz, 2 C, o-C6H5],
rac-1-(2-Diphenylphosphanyl-4-tert-butylphenoxy)-2,1Ј-bis(diphenyl-
phosphanyl)ferrocene (5a): Triphosphane 5a and tetraphosphane 6a
were formed as side products when 1 was treated with nBuLi and
2a in excess amounts. The development of a straightforward syn-
thesis protocols failed; m.p. 100–102 °C. 1H NMR (500 MHz,
CDCl3, 25 °C, TMS): δ = 1.01 [s, 9 H, C(CH3)3], 3.46–3.49 (m, 1
134.0 [d, 2J(C,P) = 21.8 Hz, 2 C, o-C6H5], 134.3 [d, 2J(C,P) =
2
20.7 Hz, 2 C, o-C6H5], 134.58 [d, J(C,P) = 20.8 Hz, 2 C, o-C6H5],
134.63 [d, 2J(C,P) = 21.3 Hz, 2 C, o-C6H5], 137.0 [d, 1J(C,P) =
12.0 Hz, 1 C, i-C6H5], 137.2 [d, 1J(C,P) = 12.8 Hz, 1 C, i-C6H5],
137.4 [d, 1J(C,P) = 11.7 Hz, 1 C, i-C6H5], 137.6 [dd, 1J(C,P) =
9.9 Hz, 4J(C,P) = 5.3 Hz, 1 C, i-C6H5], 137.9 [dd, 1J(C,P) =
10.3 Hz, 4J(C,P) = 4.8 Hz, 1 C, i-C6H5], 138.5 [d, 1J(C,P) =
12.4 Hz, 1 C, i-C6H5], 138.6 [d, 1J(C,P) = 9.0 Hz, 1 C, i-C6H5],
3
H, 3-H/C5H3), 3.51–3.54 (m, 1 H, Hα-C5H4), 3.88 [pt, J(H,H) =
2.6 Hz, 1 H, 4-H/C5H3], 3.92–3.95 (m, 1 H, Hα-C5H4), 4.08–4.11
(m, 1 H, Hβ-C5H4), 4.18–4.20 (m, 1 H, Hβ-C5H4), 4.20–4.23 (m, 1
1
139.0 [d, J(C,P) = 9.2 Hz, 1 C, i-C6H5], 144.6 (s, 1 C, 4-C/C6H3),
3
4
H, 5-H/C5H3), 6.34 [dd, J(H,H) = 8.5, J(P,H) = 4.6 Hz, 1 H, 6-
H/C6H3], 6.54 [dd, 3J(P,H) = 5.3, 4J(H,H) = 2.4 Hz, 1 H, 3-H/
C6H3], 6.85 [dd, 3J(H,H) = 8.5, 4J(H,H) = 2.4 Hz, 1 H, 5-H/C6H3],
7.13–7.39 (m, 28 H, C6H5), 7.39–7.45 (m, 2 H, C6H5) ppm.
13C{1H} NMR (125.7 MHz, CDCl3, 25 °C, TMS): δ = 31.2 [s, 3 C,
157.1 [d, 2J(C,P) = 16.6 Hz, 1 C, 1-C/C6H3] ppm. 31P{1H} NMR
(202.5 MHz, CDCl3, 25 °C, H3PO4): δ = –15.1 [d, 6J(P,P) = 6.9 Hz,
1 P, C6H3P], –23.9 [d, 3J(P,P) = 96.4 Hz, 1 P, C5H3P2], –24.7 [d,
6J(P,P) = 6.9 Hz, 1 P, C5H3OP], –25.5 [d, 3J(P,P) = 96.4 Hz, 1 P,
C H P ] ppm. IR (NaCl): ν = 3068, 3053, 3001 (=C–H), 2960,
˜
3
5
3 2
C(CH3)3], 34.1 [s, 1 C, C(CH3)3], 64.9 [d, J(C,P) = 1.5 Hz, 1 C, 5-
2925, 2868 (CH3), 1585 (C=C), 1248 (=C–O–C), 908, 824, 739, 696
(=C–H) cm–1. HRMS: m/z: calcd. for C68H58FeOP4: 1071.2862;
found 1071.2839 [M + H]+.
C/C5H3], 67.2 [d, 3J(C,P) = 3.0 Hz, 1 C, 4-C/C5H3], 68.0 (s, 1 C, 3-
C/C5H3), 69.5 [d, 1J(C,P) = 14.4 Hz, 1 C, 2-C/C5H3], 73.9 [d,
2J(C,P) = 11.2 Hz, 1 C, o-C5H4], 75.1 (m, 1 C, m-C5H4), 75.2 [d,
2J(C,P) = 18.3 Hz, 1 C, o-C5H4], 75.5 [d, 3J(C,P) = 3.9 Hz, 1 C, m-
Single-Crystal X-ray Diffraction Analysis: Crystal data for 3a-Se,
4a, and 5a-Se3 are summarized in Table 4. Data were collected with
an Oxford Gemini S diffractometer at 100 K using Mo-Kα (λ =
0.71073 Å for 3a-Se) and Cu-Kα (λ = 1.54184 Å for 4a, 5a-Se3)
radiation. The structures were solved by direct methods and refined
by full-matrix least-square procedures on F2.[31] All non-hydrogen
atoms were refined anisotropically and a riding model was em-
ployed in the refinement of the hydrogen atom positions.
2
C5H4], 113.6 (s, 1 C, 6-C/C6H3), 124.9 [d, J(C,P) = 20.3 Hz, 1 C,
1
1-C/C5H3], 125.3 [d, J(C,P) = 14.4 Hz, 1 C, 2-C/C6H3], 126.2 (s, 1
C, 5-C/C6H3), 127.8–128.6 (m, 18 C, m-C6H5 and p-C6H5), 130.6
2
2
[d, J(C,P) = 1.6 Hz, 1 C, 3-C/C6H3], 133.1 [d, J(C,P) = 19.1 Hz,
2
2 C, o-C6H5], 133.3 [d, J(C,P) = 20.2 Hz, 2 C, o-C6H5], 133.5 [d,
2J(C,P) = 19.6 Hz, 2 C, o-C6H5], 133.8 [d, J(C,P) = 20.4 Hz, 2 C,
2
o-C6H5], 134.2 [d, 2J(C,P) = 20.2 Hz, 2 C, o-C6H5], 134.3 [d,
2J(C,P) = 21.0 Hz, 2 C, o-C6H5], 136.9 [d, J(C,P) = 11.8 Hz, 1 C,
1
i-C6H5], 137.2 [d, 1J(C,P) = 11.8 Hz, 1 C, i-C6H5], 137.6 [d, 1J(C,P)
CCDC-760050 (for 3a-Se), -760051 (for 4a), and -760052 (for 5a-
Se3) contain the supplementary crystallographic data for this paper.
These data can be obtained free of charge from The Cambridge
Crystallographic Data Centre via http://www.ccdc.cam.ac.uk/data_
request/cif.
1
= 10.9 Hz, 1 C, i-C6H5], 138.7 [d, J(C,P) = 9.5 Hz, 1 C, i-C6H5],
139.1 [d, 1J(C,P) = 11.6 Hz, 1 C, i-C6H5], 139.3 [d, 1J(C,P) =
2
10.0 Hz, 1 C, i-C6H5], 144.6 (s, 1 C, 4-C/C6H3), 158.4 [d, J(C,P) =
15.4 Hz, 1 C, 1-C/C6H3] (carbon i-C5H4 was not observed) ppm.
31P{1H} NMR (202.5 MHz, CDCl3, 25 °C, H3PO4): δ = –14.3 [d,
6J(P,P) = 4.8 Hz, 1 P, C6H3P], –17.6 (s, 1 P, C5H4P), –26.0 ppm [d,
General Procedure for Suzuki Cross-Coupling: An oven-dried
Schlenk tube was charged with [Pd2(dba)3], 3 [Pd/P = 1:2 (n/n)],
boronic acid (1.5 mmol, 1.5 equiv.), powdered, anhydrous K3PO4
(637 mg, 3.0 mmol, 3.0 equiv.), and acenaphthene (154 mg,
1.0 mmol) as internal standard. The Schlenk tube was capped with
a rubber septum, evacuated and refilled with argon. This sequence
was repeated three times. Dry toluene (2 mL) was added through
the septum with a syringe and the resulting mixture was stirred at
room temperature for 5 min. The aryl halide (1.0 mmol, 1.0 equiv.)
was added with a syringe (solid aryl halides were added during
the initial charge). The reaction mixture was heated at the given
temperature with vigorous stirring for 24 h. After cooling to room
temperature, the reaction mixture was diluted with water (25 mL)
and extracted with diethyl ether (3ϫ25 mL). The combined or-
ganic extracts were dried with MgSO4 and concentrated under re-
duced pressure. The crude material obtained was purified by flash
chromatography on silica (diethyl ether).
6J(P,P) = 4.8 Hz, 1 P, C H P]. IR (NaCl): ν = 3070, 3055, 3001
˜
5
3
(=C–H), 2962, 2927, 2860 (CH3), 1585 (C=C), 1361 [C(CH3)3],
1244 (=C–O–C), 908, 824, 735, 696 (=C–H) cm–1. HRMS: m/z:
calcd. for C56H49FeOP3: 444.1246; found 444.1235 [M + 2H]2+
.
rac-1-(2-Diphenylphosphanyl-4-tert-butylphenoxy)-2,1Ј,2Ј-tris(di-
phenylphosphanyl)ferrocene (6a): 1H NMR (500 MHz, CDCl3,
25 °C, TMS): δ = 1.04 [s, 9 H, C(CH3)3], 3.09–3.11 (m, 1 H, 3-H/
C5H3OP), 3.49–3.52 (m, 1 H, 3-H or 5-H/C5H3P2), 3.93–3.95 (m,
1 H, 5-H/C5H3OP), 4.34–4.37 (m, 2 H, 4-H/C5H3OP and 3-H or
3
5-H/C5H3P2), 4.46 [pt, J(H,H) = 2.5 Hz, 1 H, 4-H/C5H4P2], 6.36
[dd, 3J(H,H) = 8.5 Hz, 4J(P,H) = 4.8 Hz, 1 H, 6-H/C6H3], 6.51 [dd,
3J(P,H) = 4.8 Hz, 4J(H,H) = 2.4 Hz, 1 H, 3-H/C6H3], 6.85 [ddd,
4
5
3J(H,H) = 8.5 Hz, J(H,H) = 2.5 Hz, J(P,H) = 0.6 Hz, 1 H, 5-H/
C6H3], 6.89–6.97 (m, 6 H, C6H5), 6.98–7.05 (m, 4 H, C6H5), 7.07–
7.36 (m, 28 H, C6H5), 7.56–7.61 ppm (m, 2 H, C6H5); 13C{1H}
NMR (125.7 MHz, CDCl3, 25 °C, TMS): δ = 31.2 [s, 3 C,
C(CH3)3], 34.1 [s, 1 C, C(CH3)3], 66.7 (m, 1 C, 5-C/C5H3OP), 67.0
(m, 1 C, 4-C/C5H3OP), 69.1 [d, 1J(C,P) = 17.5 Hz, 1 C, 2-C/
C5H3OP], 69.9 [d, 2J(C,P) = 4.9 Hz, 1 C, 3-C/C5H3OP], 75.6 [pt,
2+3J(C,P) = 4.1 Hz, 1 C, 3-C or 5-C/C5H3P2], 77.2 [d, 3J(C,P) =
4.4 Hz, 1 C, 4-C/C5H3P2], 78.5 [dd, 2J(C,P) = 8.7 Hz, 3J(C,P) =
4.1 Hz, 1 C, 3-C or 5-C/C5H3P2], 83.8 [dd, 2J(C,P) = 29.2 Hz,
For reactions conducted at low catalyst loadings (Յ0.5 mol% Pd)
stoichiometric solutions of [Pd2(dba)3] and 3 in toluene were pre-
pared and were added to the Schlenk tube instead of the solvent.
Supporting Information (see also the footnote on the first page of
1
this article): Full experimental details as well as H, 13C, 31P, and
1J(C,P) = 7.4 Hz, 1 C, 1-C or 2-C/C5H3P2], 85.1 [dd, 2J(C,P) = 119Sn NMR spectra for all compounds.
Eur. J. Inorg. Chem. 2010, 4811–4821
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
4819

D. Schaarschmidt, H. Lang
FULL PAPER
Table 4. Crystal and intensity collection data for 3a-Se, 4a, and 5a-Se3.
3a-Se
4a
5a-Se3
Formula weight
Chemical formula
Crystal system, space group
a [Å]
b [Å]
c [Å]
597.35
702.55
1123.59
C32H31FeOPSe
monoclinic, P21/c
10.3138(2)
30.3315(7)
8.4704(2)
90.0, 91.432(2), 90.0
2648.99(10)
1.498
C44H40Fe2OP2
orthorhombic, Pna21
21.2970(2)
9.68120(10)
17.2355(2)
90.0, 90.0, 90.0
3553.62(6)
1.313
C56H49FeOP3Se3
monoclinic, C2/c
21.4815(10)
12.3484(11)
38.2575(13)
90.0, 103.853(2), 90.0
9853.1(10)
1.515
α, β, γ [°]
V [Å3]
ρcalcd. [gcm–3]
F(000)
Crystal dimensions [mm]
Z
1224
0.20ϫ0.20ϫ0.20
4
1472
0.30ϫ0.25ϫ0.20
4
4528
0.20ϫ0.20ϫ0.05
8
Max., min. transmission
0.658, 0.673
2.028
1.000, 0.659
4.508
1.000, 0.650
6.212
µ [mm–1]
θ [°]
Index ranges
2.81–29.06
–12 Յ h Յ 12
–37 Յ k Յ 37
–10 Յ l Յ 10
32950/5198
5198/0/325
0.0343
0.0260, 0.0617
0.0332, 0.0630
1.034
4.15–62.50
–24 Յ h Յ 24
–10 Յ k Յ 11
–19 Յ l Յ 19
14838/5020
5020/1/433
0.0367
0.0274, 0.0665
0.0296, 0.0670
0.981
4.16–61.99
–24 Յ h Յ 24
–12 Յ k Յ 14
–43 Յ l Յ 43
22453/7681
7681/0/577
0.0571
0.0588, 0.1565
0.0795, 0.1714
1.125
Total/unique reflections
Data/restraints/parameters
Rint
R1, wR2 [IՆ2σ(I)][a]
R1, wR2 (all data)
Goodness-of-fit (S) on F2 [b]
Largest diff. peak, hole [eÅ–3]
Absolute structure parameter[32]
0.442, –0.355
–
0.268, –0.221
–0.001(3)
1.054, –1.430
–
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This work was supported by the Deutsche Forschungsgemeinschaft
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and Innospec Specialty Chemicals for generous funding. D. S. is
grateful to the Fonds der Chemischen Industrie for a fellowship,
Dr. C. Schreiner for fruitful discussions and Prof. Dr. K. Banert
and Dr. M. Hagedorn (Department of Organic Chemistry, TU
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4
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Received: July 1, 2010
Published Online: September 3, 2010
Eur. J. Inorg. Chem. 2010, 4811–4821
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
4821