Synthesis, Isolation and Crystal Structures of the Metalated Ylides [Cy3P-C-SO2Tol]M (M = Li, Na, K)

Article abstract of DOI:10.1002/zaac.201900333

The preparation and isolation of the metalated ylides [Cy₃PCSO₂Tol]M (^Cy1-M) (with M = Li, Na, K) are reported. In contrast to its triphenylphosphonium analogue the synthesis of ^Cy1-M revealed to be less straigh

Full text of DOI:10.1002/zaac.201900333

Journal of Inorganic and General Chemistry
DOI: 10.1002/zaac.201900333
ARTICLE
Zeitschrift für anorganische und allgemeine Chemie
Synthesis, Isolation and Crystal Structures of the Metalated Ylides
[Cy3P-C-SO2Tol]M (M = Li, Na, K)
Heidar Darmandeh,[a] Thorsten Scherpf,[a] Kai-Stephan Feichtner,[a] Christopher Schwarz,[a] and
Viktoria H. Gessner*[a]
Dedicated to Manfred Scheer on Occasion of his 65th Birthday
Abstract. The preparation and isolation of the metalated ylides yldiides was finally achieved with strong bases such as nBuLi, NaNH2,
[Cy3PCSO2Tol]M (Cy1-M) (with M = Li, Na, K) are reported. In con-
trast to its triphenylphosphonium analogue the synthesis of Cy1-M re-
vealed to be less straight forward. Synthetic routes to the phosphonium
or BnK. In the solid state, the lithium compound forms a tetrameric
structure consisting of a (C–S–O–Li)4 macrocycle, which incorporates
an additional molecule of lithium iodide. The potassium compound
salt precursor Cy1-H2 via different methods revealed to be unsuccessful forms a C4-symmetric structure with a (K4O4)2 octahedral prism as
or low-yielding. However, nucleophilic attack of the ylide Cy3P = CH2
at toluenesulfonyl fluoride under basic conditions proved to be a high-
yielding method directly leading to the ylide Cy1-H. Metalation to the
central structural motif. Upon deprotonation the P–C–S linkage un-
dergoes a remarkable contraction typical for metalated ylides.
1-M[8] and 2-M[9] (with M = Li, Na, K) have been prepared
in gram-scale and applied in synthesis. For example, our group
demonstrated that 1-M and 2-M are excellent reagents for
ylide-functionalizations,[10] which represents a powerful tool
for the electronic manipulation of main group com-
pounds.,[11,12] As such, electron-deficient species like
borenium ions and tetrylenes were successfully isolated start-
ing from 1-Na.[13] Likewise, a series of ylide-substituted phos-
phines were prepared which turned out to be excellent ligands
for homogeneous catalysis.[14]
Introduction
Since the first synthesis of an ylide more than one century
ago and the pioneering work by Wittig, Staudinger and
others,[1] ylides have become an important class of reagents.
They are nowadays routinely used in organic synthesis in a
variety of transformations, as well as in catalysis, e.g. as group
transfer reagents, or as ligands in coordination chemistry.[2]
Besides simple ylides, also their metalated congeners, the so-
called yldiides, have early been discussed and applied in syn-
thesis.,[3,4] For example, Corey reported on an enhanced reac-
tivity of yldiides in Wittig reactions with hindered ketones,[5]
while Bestmann demonstrated their potential in a number of
cascade reactions, such as for the syntheses of alkynes and
carbacycles.[6] Despite these early reports in the 1980s, their
isolation was for a long time limited to very few examples.[6a]
This is mostly due to the high reactivity of metalated ylides,
which is strongly connected with the high charge concentration
at the ylidic carbon atom.
Until today, only five metalated ylides have been isolated
and also structurally characterized (Figure 1),[7] whereat only
* Prof. Dr. V. H. Gessner
E-Mail: viktoria.gessner@rub.de
Figure 1. Isolated and structurally characterized metalated ylides.
[a] Chair of Inorganic Chemistry II
Faculty of Chemistry and Biochemistry
Ruhr University Bochum
Universitätsstrasse 150
44780 Bochum, Germany
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/zaac.201900333 or from the au-
thor.
© 2020 The Authors. Published by Wiley-VCH Verlag GmbH &
Co. KGaA. · This is an open access article under the terms of the
Creative Commons Attribution-NonCommercial License, which
permits use, distribution and reproduction in any medium, provided
the original work is properly cited and is not used for commercial
purposes.
During our studies on the use of 1-M in main group chemis-
try we observed the C–H activation at one of the phenyl groups
of the phosphonium moiety as side-reaction leading to the pro-
tonation and subsequently to the cleavage of an ylide ligand
from the main group metal.[13a] In order to further exploit the
use of metalated ylides for the stabilization of reactive com-
pounds we thus became interested in replacing the PPh3 moi-
ety by a tricyclohexyl phosphonium moiety which should less
tend to undergo any CH activation processes and hence lead
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to more stable products. Here, we report on the preparation of rect formation of ylide Cy1-H under the reaction conditions
Cy1-M, the cyclohexyl derivative of 1-M. Despite this rather since ylide Cy3P=CH2 simultaneously acts as reagent as well
small change in the molecular structure the synthesis of as base and deprotonates the initially formed phosphonium salt
Cy1-M turned out to be surprisingly more difficult than ex- Cy1-H2 thus yielding Cy1-H and [Cy3PMe]F. Therefore, under
pected.
optimized conditions Cy3PCH2 was treated with one equiv. of
tosyl fluoride in the presence of a further equiv. NaHMDS to
prevent the reformation of [Cy3PMe]F. Thus, Cy1-H could be
obtained in only one reaction step as colorless solid in excel-
lent yields of 90%. Cy1-H was characterized by NMR and IR
spectroscopy as well as XRD and elemental analysis. The ylide
exhibits a singlet at δP = 26.8 ppm in the 31P{1H} NMR spec-
trum and a doublet at δH = 1.86 ppm with a coupling constant
of 2JPC = 8.4 Hz in the 1H NMR spectrum. The 13C{1H} NMR
signal of the ylidic carbon appears at δ = 26.1 ppm with a
Results and Discussion
For the preparation of Cy1-M, we at first addressed a syn-
thetic route analogous to that reported for the PPh3 system.[8]
Thus, tricyclohexylphosphine and (iodomethyl)tolylsulfone
were reacted at different temperatures to access the phosphon-
ium salt Cy1-H2 in the first reaction step (Route A, Scheme 1).
However, in contrast to the phenyl compound no selective for-
mation of Cy1-H2 was observed due to several competing side-
reactions such as reduction of the sulfonyl group, oxidation of
PCy3 and deprotonation by the more basic PCy3. This reaction
was observed under different reaction conditions (in C6D6 or
without solvent; at 60 °C or room temperature). Likewise, re-
action of the halo phosphonium salts [Cy3PX]X (with X = Br,
I) with lithiated methyl(p-tolyl)sulfone proved to be unsuccess-
ful (Route C). No product formation was observed by NMR
spectroscopy. In contrast, treatment of the (iodomethyl)phos-
phonium salt with sodium sulfinate (Route B) delivered the
desired phosphonium salt Cy1-H2, albeit only in small quanti-
ties together with a series of by-products. Due to the low nu-
cleophilicity of the sulfinate harsh reaction conditions in re-
fluxing DMF or DMSO were necessary to observe detectable
amounts of Cy1-H2. Albeit Cy1-H2 could be isolated in pure
form by this method and spectroscopically as well as structur-
ally characterized (see below), it was impossible to further im-
prove the reaction to reliably yield sufficient amounts of
Cy1-H2 for further synthesis.
1
1
large JPC coupling constant of 105 Hz (cf. 44.5 ppm; JCP
=
31.3 Hz in Cy1–H2), which is in line with the increased s-char-
acter in the P–C bond of Cy1-H compared to the phosphonium
salt precursor Cy1–H2. This is also reflected in the larger
P–C–S angle in the molecular structure (Figure 2, Table 1) of
Cy1-H (127.63(19)°] compared to that observed in Cy1-H2
[117.85(9)°].
Scheme 2. Preparation of ylide Cy1-H.
Figure 2. Molecular structures of phosphonium salt Cy1-H2 and ylide
Cy1-H. Thermal ellipsoids at the 50% probability level. Selected bond
lengths and angles are given in Table 1. Crystallographic details are
given in the Supporting Information.
With ylide Cy1-H in hand, we next attempted its metalation
to Cy1-M. At first, alkali metal HMDS bases were tested which
were successfully applied to access the PPh3 analogue 1-M.
However, no reaction was observed with Cy1-H even after a
prolonged reaction time. This suggests, that the more electron-
rich PCy3 unit significantly lowers the CH acidity of the ylide.
Accordingly, stronger metal bases were tested. Indeed, moni-
Scheme 1. Examined pathways for the synthesis of the tricyclohexyl-
phosphonium salt Cy1-H2.
In order to obtain high quantities of the ylide precursor for toring of the metalation reaction by 31P{1H} NMR spec-
its metalation we turned our attention towards a further syn- troscopy revealed the successful formation of the different al-
thetic pathway, the nucleophilic attack of the methylenephos- kali metal yldiides Cy1-M, when using n-butyllithium, benzyl
phorane, Cy3PCH2, on
a suitable sulfonyl electrophile potassium (BnK), and sodium amide, respectively (Scheme 3).
(Scheme 2). To this end, tricyclohexylphosphonium methylide, The formation of the alkali metal yldiides is evidenced by a
Cy3PCH2, was in situ formed from [Cy3PMe]I and sodium distinct high-field shift of the signal in the 31P{1H} NMR spec-
hexamethyldisilazide (NaHMDS) and subsequently treated trum compared to the ylide precursor Cy1-H (Table 1). For ex-
with tosyl fluoride. Sulfonyl fluorides have proven to be excel- ample, addition of BnK or NaNH2 gave rise to a broad singlet
lent electrophiles for the formation of C–S bonds.[15,17] NMR at 3.2 ppm and 6.1 ppm, respectively (cf. 26.7 ppm for Cy1-H).
spectroscopic studies of the reaction mixture revealed the di- Albeit all reactions were highly selective as judged by NMR
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Table 1. Important NMR spectroscopic and crystallographic properties of Cy1-H2, Cy1-H, and its metalated congeners Cy1-Li and Cy1-K.
Cy1-H2
Cy1-H
[
Cy1-Li]4·LiI
[
Cy1-K]8
P–C1 /Å
S–C1 /Å
S–O1 /Å
S–O2 /Å
P–CCy /Å
M-C1 /Å
1.8279(17)
1.7846(17)
1.4423(13)
1.4381(13)
1.8237(12)
–
1.718(3)
1.662(3)
1.450(3)
1.451(3)
1.836(8)
–
1.676(2)
1.602(2)
1.4800(18)
1.4953(16)
1.855(16)
2.159(5)
127.48(15)
10.1
1.669(6)
1.591(6)
1.494(4)
1.471(4)
1.850(6)
2.906(6)
127.20(4)
3.1
a)
P–C1–S /°
117.85(9)
35.4
127.63(19)
26.8
δ = 31P /ppm
a) Average values.
studies, isolation turned out to be most facile for the lithium geometry. The additional lithium ion Li2 is complexed in the
and the potassium compound. Reaction of a suspension of center of the resulting pocket and lies on the S4 axis of the
Cy1-H in n-pentane with one equiv. nBuLi yielded the highly molecule.
soluble Cy1-Li, which can easily be purified by filtration from
the insoluble starting materials and thus could be isolated as
yellow solid in 90% yield. Cy1-Li was characterized by multi-
nuclear NMR spectroscopy, elemental and XRD analysis. The
7Li NMR signal appears as broad singlet at 0.6 ppm, the 31P
NMR signal at δ = 10.1 ppm and is thus the most downfield
shifted signal in the whole series of the alkali metal yldiides
Cy1-M. The potassium compound Cy1-K could also be isolated
as pure solid in excellent yields of up to 98%.
Scheme 3. Metalation of Cy1-H with alkali metal bases to Cy1-M
(M = Li, Na, K) (* = NMR yield).
Single crystals of Cy1-Li were grown by slow vapor dif-
fusion of n-pentane into a saturated THF solution of the yldiide
at –30 °C and analyzed by XRD techniques. The yldiide crys-
tallizes in the tetragonal space group P42/n (Figure 3) as a S4
symmetric tetramer with an additional molecule of lithium iod-
ide (present from the synthesis of Cy1-H via route B).[16] The
monomeric subunit (asymmetric unit) consists of one yldiide,
in which the lithium ion is coordinated by the ylidic carbon
atom, one oxygen of the sulfonyl group and a THF molecule.
Aggregation of the monomers to the tetramer is realized
through the coordination of the second oxygen atom of the
sulfonyl moiety, which bridges the lithium ions of monomeric
subunits. Thus, a highly symmetric (C–S–O–Li)4 macrocycle
is formed (Figure 4), whose outer sphere is fully covered by
Figure 3. Molecular structure of (Cy1-Li)4·LiI·4THF. (Top) Top view,
(bottom) side view; the counter-anion is not shown. Ellipsoids at the
50% probability level. Selected bond lengths /Å and angles /°: Li1–
C1 2.159(5) Å; Li1–O2 2.022(5), Li1–O1’ 1.875(5), Li2–O2
1.9354(15). S1–C1–P1 127.48(15), S1–C1–Li1 86.07(15), P1–C1-Li
146.41(18). Further structure parameters are provided in Table 1, crys-
the coordinating THF molecules and phosphonium groups.
This structure is most probably responsible for the high solu-
bility of the compound also in hydrocarbon solvents, since the
polar moieties of the complex are well covered in the inner
core of the structure. In this context it is interesting to note
that the macrocycle itself adopts not a planar but a bowl-like tallographic details are given in the Supporting Information.
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Figure 4. Drawing of the inner core of the structure of Cy1-Li.
In the molecular structure of Cy1-Li, the ylidic carbon atom
C1 adopts a planar arrangement with an ideal sum of angles
of 360.0(2)°. The C1–Li1 distance amounts to 2.159(5) Å and
is thus in the typical range for organolithium aggregates.[17]
A
comparison of the important bond lengths and angles in
Cy1-Li in comparison to its protonated precursors is given in
Table 1. As already observed for yldiide 1-K, the central P–
C–S linkage undergoes a remarkably contraction upon each
deprotonation step due to increased electrostatic attractions
with increasing charge at the central carbon atom. The S–C
and P–C bonds thus shorten from 1.785(2) and 1.828(1) Å in
Cy1–H2 to 1.602(2) and 1.676(2) Å in Cy1-Li. Likewise, the
S–O and P–CCy bonds lengthen slightly because of negative
hyperconjugation effects. Furthermore, the P-C-S angle widens
from 117.9(1)° in the phosphonium salt to 127.6(2)° in the
yldiide indicating an increase of s-character upon deproton-
ation, which is retained after the second deprotonation.
Overall, the changes in the bond lengths and angles in
Cy1-Li relative to its protonated precursors is similar to the
trends observed for the PPh3-substituted compounds.[8] How-
ever, it is interesting to note that in comparison to the PPh3-
substituted compounds, the S–C bonds in the PCy3-substituted
compounds are shorter by approx. 20–30 pm. This can be ex-
plained by the lower ability of the PCy3 compared to the PPh3
Figure 5. Molecular structure of [(Cy1-K)8·2THF]. (Top) side view,
(bottom) top view. Ellipsoids at the 50% probability level. Non-coordi-
nating THF solvent molecules as well as disordered moieties are omit-
ted for clarity. Selected bond lengths /Å and angles /°: K1–C1
2.906(6), K2–C27 2.906(6), K1–O3 2.672(4), K1–O1 2.709(4), K1–
group to stabilize the negative charge at the ylidic carbon atom O1’ 2.764(4), K1–O2’ 2.767(5). Further structure parameters are pro-
vided in Table 1, crystallographic details are given in the Supporting
Information.
by electrostatic and negative hyperconjugation effects. There-
fore, the electrostatic attraction in the C-S linkage increases
and hence the bond shortens.
C4 axis (only one orientation shown in Figure 5).[18] Unfortu-
nately, the quality of the crystals was rather low due to highly
disordered solvent molecules (see ESI). However, the trends in
the bond lengths are similar to those observed for the lithium
compound discussed above (Table 1).
Besides the structure of the lithium yldiide we also at-
tempted the elucidation of structure of the potassium and so-
dium compound. While no crystals of sufficient quality could
be obtained for Cy1-Na, single-crystals of Cy1-K could be ob-
tained by storage of a saturated THF solution at –30 °C.
Cy1-K crystallizes as C4-symmetric octamer in the tetragonal
The central structural motif of Cy1-K consists of an octago-
space group P4/n with two additional THF molecules on the nal prism formed by the potassium and oxygen atoms of the
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General Methods: All experiments were carried out in a dry, oxygen-
sulfonyl group with K–O distances between 2.672(4) and
free argon atmosphere using standard Schlenk techniques. Involved
solvents were dried using an MBraun SPS-800 (THF, Toluene, Et2O,
DCM, n-Pentane, n-Hexane) or dried in accordance with standard pro-
cedures. 1H, 13C{1H}, 31P{1H}, 7Li NMR spectra were recorded on
Avance-500 or Avance-400 spectrometers at 25 °C if not stated other-
wise. All values of the chemical shift are in ppm regarding the δ-
scale. All spin-spin coupling constants (J) are printed in Hertz (Hz).
To display multiplicities and signal forms correctly the following ab-
breviations were used: s = singlet, d = doublet, m = multiplet, br =
2.767(5) Å (Figure 6). The O–K–O angles amount to approx.
83.4(1)° within each K2O2 face and to approx. 133° between
the faces. Each potassium atom is coordinated by the ylidic
carbon atom, four oxygens of the sulfonyl groups as well as
by the two loosely bound THF molecules on top and below
the octahedral prism and weak C-H interactions with the cyclo-
hexyl moieties (not shown in Figure 4). The P–C and S–C
bonds are shortened compared to the ylide and the phosphon-
ium salt and in the range of those found in the lithium com- broad signal. Signal assignment was supported by DEPT, APT, HSQC
pound Cy1-Li.
and HMBC experiments. Elemental analyses were performed on an
Elementar vario MICRO-cube elemental analyzer.
Synthesis of [Cy3P-Me]I: Tricyclohexylphosphine (16.00 g,
57.05 mmol, 1.00 equiv.) was dissolved in toluene (200 mL). Methyl
iodide (3.8 mL, 61.05 mmol, 1.07 equiv.) was added dropwise to the
solution at room temp. During the addition, a white solid precipitated
out of the solution. The reaction mixture was stirred at room tempera-
ture until full precipitation was achieved (2 h). Next, the suspension
was filtered and washed with Et2O (3ϫ10 mL). The solid was dried
in vacuo (1ϫ10–3 mbar) for 4 h, giving [Cy3P-Me]I as a white,
amorphous powder (98%, 23.50 g). 1H NMR (CD2Cl2, 400 MHz): δ =
2.5 (m, 3 H, PCy-CH), 2.0–1.9 (m, 11 H, PCy-CH2), 1.9 (d, J =
12.1 Hz, 3 H, CH3), 1.8–1.8 (m, 3 H, PCy-CH2), 1.6–1.2 (m, 16 H,
PCy-CH2) ppm. 31P{1H} NMR (CD2Cl2, 161.9 MHz): δ = 33.7 (s)
ppm. The obtained signals are in accordance with literature values.[19]
Synthesis of Cy1-H: [Cy3P-Me]I (10.00 g, 23.68 mmol, 1.00 equiv.)
and NaHMDS (8.77 g, 47.82 mmol, 2.02 equiv.) were placed in a
500 mL Schlenk flask. THF (150 mL) was added, giving a white sus-
Figure 6. Drawing of the inner core of the structure of Cy1-K.
pension which was stirred for 30 min at room temp. In a second
Schlenk flask, p-toluenesulfonyl fluoride (4.12 g, 23.68 mmol,
1.00 equiv.) was dissolved in THF (25 mL) and this solution was
slowly added to the suspension via cannula, upon which a color change
from white to a deep brown occurred. The reaction mixture was stirred
Conclusions
In conclusion, we have successfully developed a synthetic
protocol for the high-yielding isolation of the tricyclohexyl-
phosphonium-substituted metalated ylides [Cy3PCSO2Tol]M
overnight, and the solvent was removed in vacuo. The residue was
taken up in a dichloromethane/toluene mixture (50 mL/250 mL) and
the resulting suspension was subsequently filtered over celite to obtain
a clear yellow solution. Removal of the solvent under reduced pressure
yielded an off-white solid, which was washed with n-hexane
(5ϫ25 mL). After drying in vacuo (1ϫ10–3 mbar) for 4 h at 70 °C,
the pure product was obtained as a white solid (90%, 9.80 g). 1H NMR
(
Cy1-M) (with M = Li, Na, K). The synthesis was ac-
complished by reaction of tricyclohexylphosphonium meth-
ylide with tosyl fluoride under basic conditions thus directly
forming the ylide precursor Cy1-H, which was subsequently
deprotonated with strong metal bases. This deprotonation was
found to be considerably less facile than in case of the PPh3
analogue thus demonstrating the pronounced acidifying prop-
erties of a PPh3 moiety compared to the PCy3 unit. The molec-
ular structures of the lithium and potassium yldiide could be
elucidated by XRD analysis. In the solid state, Cy1-Li forms a
S4-symmetric tetrameric structure with one additional lithium
iodide molecule, while Cy1-K exhibits a C4 symmetric struc-
ture with an octahedral prism as central structural motif. In
the structures, the central P–C and S–C bonds are shortened
compared to the ylide precursor due to electrostatic interac-
2
(CD2Cl2,400 MHz): δ = 7.69 (d, JHH = 8.2 Hz, 2 H, o-CH), 7.18 (d,
2JHH = 7.9 Hz, 2 H, m-CH), 2.36 (s, 3 H), 2.27–2.09 (m, 3 H,
2
PCy3-CH), 1.86 (d, JPH = 8.4 Hz, 1 H, PCHS), 1.85–1.75 (m, 11 H,
PCy3–CH2), 1.73–1.65 (m, 3 H, PCy3–CH2), 1.47–1.32 (m, 6 H,
PCy3–CH2), 1.31–1.06 (m, 10 H, PCy3–CH2). 13C{1H} NMR
(CD2Cl2, 100.6 MHz): δ = 149.7 (ipso-C), 140.2 (p-C), 129.5 (m-CH),
2
3
125.5 (o-CH), 33.1 (d, JCP = 50.8 Hz, PCy3-CH), 27.8 (d, JCP
=
3.1 Hz, PCy3–CH2), 27.6 (d, 2JCP = 12.3 Hz, PCy3–CH2), 26.5 (d, 4JCP
= 1.6 Hz, PCy3–CH2), 26.1 (d, 2JPH = 105 Hz, PCS), 21.6 (p-Tol-CH3).
31P{1H} NMR (CD2Cl2, 161.9 MHz): δ = 26.8 (s) ppm. EA: calcd: C:
69.61, H: 9.21, S: 7.15%, found C 69.26, H: 9.04, S: 7.38%.
Synthesis of Cy1-Li: Cy1-H (3.63 g, 8.09 mmol, 1.0 equiv.) was sus-
tions. Current studies are focusing on the application of the pended in n-pentane (100 mL). nBuLi (1.53 m in hexanes, 5.29 mL,
1.0 equiv.) was added dropwise to the suspension at 0 °C. The reaction
mixture was warmed to room temp. and stirred for 1 h. The suspension
was filtered via cannula furnishing a yellow solution. Removal of the
solvent under reduced pressure and drying in vacuo (1ϫ10–3 mbar)
for 4 h at 40 °C afforded Cy1-Li as a yellow powder (90%, 3.33 g).
yldiide in main group chemistry.
Experimental Section
Experimental Details: Details regarding the synthesis of Cy1-H2 via
2
1H NMR ([D8]THF, 400 MHz): δ = 7.85 (d, JHH = 7.7 Hz, 2 H, m-
2
route A, B and C are given in the Supporting Information.
CH), 6.96 (d, JHH = 7.7 Hz, 2 H, o-CH), 2.28 (s, 3 H, p-Tol-CH3),
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1.95–1.84 (m, 10 H, PCy-CH+CH2), 1.70–1.65 (m, 6 H,, PCy-CH2),
Acknowledgements
1.61–1.57 (m, 3 H,, PCy-CH2), 1.43–1.38 (m, 4 H,, PCy-CH2), 1.20–
1.10 (m, 10 H,, PCy-CH2). 13C{1H} NMR ([D8]THF, 100.6 MHz): δ =
155.5 (ipso-C), 137.1 (p-C) 128.4 (m-CH), 126.9 (o-CH), 36.9 (d, J =
52.8; PCy3-CH), 28.7 (PCy3–CH2), 28.6 (d, J = 8.4, PCy3–CH2), 27.5
(PCy3–CH2), 21.4 (p-Tol-CH3). The signal for the PCS bridge could
not be observed. 31P{1H} NMR ([D8]THF,162 MHz): δ = 10.1 (s)
This project has received funding from the European Research Council
under the European Union’s Horizon 2020 research and innovation
program (Starting grant no 677749).
7
Keywords: Alkali metals; Ylides; Carbanions; Structure elu-
ppm. Li NMR ([D8]THF, 155.6 MHz): δ = 0.6 (s) ppm. EA: calcd.:
cidation; Phosphorus ligands
C: 68.70, H: 8.87, S: 7.05%; found: C: 68.73, H: 8.84, S: 7.03%
Synthesis of Cy1-K: Benzyl potassium (0.32 g, 2.45 mmol, 1.1 equiv.)
and Cy1-H (1.00 g, 2.22 mmol, 1.0 equiv.) were placed into a Schlenk
tube and toluene (25 mL) was added. The red reaction mixture was
stirred for 5 min at room temp. and was subsequently filtered via a
filter cannula. A dark yellow solution was obtained. The solvent was
removed under reduced pressure and the residue was dried in vacuo
(1ϫ10–3 mbar) for 3 h at 40 °C to yield CyYS-K as a dark yellow
powder (98%, 532 mg). Single crystals of Cy1-K were grown by stor-
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a
saturated THF solution at –30 °C. 1H NMR
([D8]THF,400 MHz): δ = 7.79 (br., 2 H, m-CH), 6.91 (br., 2 H, o-CH),
2.28 (s, 3 H, p-Tol-CH3), 1.87–1.75 (m, 8 H, PCy-CH+CH2), 1.71–
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([D8]THF, 100.6 MHz): δ = 157.3 (ipso-C), 136.2 (p-C) 128.6 (m-CH),
126.3 (o-CH), 37.4 (d, J = 52.5 Hz; PCy3-CH), 28.9 (PCy3–CH2), 28.8
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bridge could not be observed. 31P{1H} NMR ([D8]THF,162 MHz): δ =
3.2 (s, br) ppm. EA: calcd.: C: 64.16, H: 8.28, S: 6.59%; found: C:
64.50, H: 8.30, S: 6.88%.
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Synthesis of Cy1-Na: Sodium amide (5 mg, 128 μmol, 1.01 equiv.) and
Cy1-H (57 mg, 127 μmol, 1.0 equiv.) were placed into a J. Young NMR
tube and [D8]THF (0.5 mL) was added. The tube was shaken on an
IKA® ROCKER 3D digital at room temp. overnight. 31P-NMR spec-
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1
protonation of the ylidic carbon atom. H NMR ([D8]THF,400 MHz):
δ = 7.80 (br., 2 H, m-CH), 6.90 (br., 2 H, o-CH), 2.27 (s, 3 H,
p-Tol-CH3), 1.86–1.78 (m, 8 H, PCy-CH+CH2), 1.71–1.64 (m, 6 H,
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PCy-CH2), 1.18–1.04 (m, 10 H, PCy-CH2) ppm. 31P{1H} NMR
([D8]THF,162 MHz): δ = 6.1 (s, br) ppm.
Single-crystal X-ray Diffraction Analyses: Data collection of all
compounds was conducted with Rigaku XtaLAB Synergy (Cy1-H,
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oil (perfluoropolyalkylether). Crystal structure determinations were af-
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using full-matrix least-squares techniques on F2 with the Shelx soft-
ware package[20] and expanded using Fourier techniques. Data collec-
tion parameters are given in Tables S1 and S2 (Supporting Infor-
mation).
Crystallographic data (excluding structure factors) for the structures in
this paper have been deposited with the Cambridge Crystallographic
Data Centre, CCDC, 12 Union Road, Cambridge CB21EZ, UK.
Copies of the data can be obtained free of charge on quoting
the depository numbers CCDC-1971569, CCDC-1971570, CCDC-
1971571, and CCDC-1971572. (Fax: +44-1223-336-033; E-Mail:
deposit@ccdc.cam.ac.uk, http://www.ccdc.cam.ac.uk)
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Synthesis, Isolation and Crystal Structure of the Metalated Ylide
[Cy3P-C-SO2Tol]M.
Z. Anorg. Allg. Chem. 2020, 1–8
www.zaac.wiley-vch.de
6
© 2020 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Journal of Inorganic and General Chemistry
ARTICLE
Zeitschrift für anorganische und allgemeine Chemie
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Received: December 12, 2019
Published Online: ᭿
Z. Anorg. Allg. Chem. 2020, 1–8
www.zaac.wiley-vch.de
7
© 2020 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Journal of Inorganic and General Chemistry
ARTICLE
Zeitschrift für anorganische und allgemeine Chemie
H. Darmandeh, T. Scherpf, K.-S. Feichtner, C. Schwarz,
V. H. Gessner* ................................................................... 1–8
Synthesis, Isolation and Crystal Structures of the Metalated
Ylides [Cy3P-C-SO2Tol]M (M = Li, Na, K)
Z. Anorg. Allg. Chem. 2020, 1–8
www.zaac.wiley-vch.de
8
© 2020 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim