Full Paper
(m; C5-Cp), 81.0 (m; C2+C3-Cp), 76.2 ppm (m; C1-Cp); EI-MS
(2008C): m/z (%): 923 (100) [M+], 845 (10) [MÀPh+], 737 (10)
[MÀPPh2+]; elemental analysis calcd (%) for C58H46FeP4: C 75.50, H
5.02; found: C 75.30, H 4.93.
rich monophosphanes and diphosphanes that are often the
popular choice in this field.
Experimental Section
Catalytic thioetherification reactions
General conditions
In a typical experiment, the thiophenol derivative (2 mmol), hetero-
aromatic halide (2 mmol), [{PdCl(h3-C3H5)}2] (0.002 mmol, 0.1 mol%),
L7 (0.004 mmol, 0.2 mol%), and tBuONa (4 mmol) were introduced
into a Schlenk tube equipped with a magnetic stirring bar. The
Schlenk tube was purged several times with argon, toluene (5 mL)
was added, and the Schlenk tube was placed in an oil bath at
1208C. The reactants were allowed to stir for 17 h (the reaction
times were not optimized). A sample of the reaction mixture was
analyzed by GC and GC-MS analysis to determine the conversion
and selectivity before purification. At room temperature, the reac-
tion mixture was then diluted with diethyl ether (5 mL), filtered,
and concentrated. The crude material was purified by flash chro-
matography on silica gel.
All the reactions and workup procedures were performed in an
inert argon atmosphere by using conventional vacuum-line and
Schlenk techniques. The reactions were carried out in oven-dried
(1158C) glassware. The solvents were distilled over appropriate
drying and deoxygenating agents prior to use. 1H, 31P, 19F, and
13C NMR spectroscopy was performed on a 600 or 500 MHz Bruker
Avance II and a 300 MHz Bruker Avance spectrometer. Electrospray
exact-mass spectrometric analyses were performed on a Bruker mi-
croOTOF-Q instrument at the PACSMUB of the Institut de Chimie
Molꢀculaire de l’Universitꢀ de Bourgogne (ICMUB—UMR CNRS
6302). The elemental analyses were performed on a Fisons EA 1108
apparatus. The GC and GC-MS analyses were performed, respec-
tively, on a Supelco equity-5 capillary column on a Shimadzu GC-
2014 (GC) or an HP-5 capillary column (30 m; GC-MS). Except for
ligand L7, the polyphosphanes used in the present study are com-
mercially available from Strem Chemicals (under the name Hierso-
PHOS). CCDC-902497 contains the supplementary crystallographic
data for this paper. These data can be obtained free of charge
from The Cambridge Crystallographic Data Centre via
Acknowledgements
This work was supported by the CNRS (M.P.) under the 3MIM
program (P4-project on Palladium Cross-Coupling Methodolo-
gy), the Singapore—MIT Alliance (N.W. and L.C.), the France-
Singapore MERLION program (V.R.) jointly from the French Min-
istry of Foreign Affairs and the National University of Singa-
pore, and the Rꢀgion Bourgogne (PARI-SMT8). We thank S.
Royer and D. Poinsot for their technical support.
Computational methods
The reaction free energies and activation free-energy barriers were
calculated by using DFT with the PBE0 functional[27] (DFT-PBE0) as
implemented in the Gaussian09 package[28] and by using the
def2-SV(P) basis set to optimize the structures and compute ther-
mal and entropy corrections with the rigid rotor-harmonic oscilla-
tor approximation.[29] To minimize basis-set superposition errors,
single-point electronic energies were further calculated for all the
final structures by using a larger def2-TZVP basis set. The reported
free energies combine the def2-TZVP electronic energies with
def2-SV(P) thermal and entropy calculations. Gibbs free energies
were computed at 1158C. Solvent effects for toluene were included
by using the solvation model density (SMD).[30] All the possible
conformations were considered, and only the structures with the
lowest Gibbs free energy in toluene at 1158C computed with the
def2-SV(P) basis set are reported.
Keywords: binuclear catalyst · density-functional calculations ·
phosphane ligands · tetradentate ligands · thioetherification
[1] a) Z. Yu in Homogeneous Catalysis for Unreactive Bond Activation (Ed.: Z.-
J. Shi), Wiley-VCH, Weinheim, 2014; b) L. Wang, W. Hea, Z. Yu, Chem.
Wiley-VCH, Weinheim, 2009.
[2] a) P. Emond, J. Vercouillie, R. Innis, S. Chalon, S. Mavel, Y. Frangin, C.
b) B. C. H. May, J. A. Zorn, J. Witkop, A. C. Wallace, G. Legname, S. B.
Synthesis of tetraphosphane L7
[8] C. Mispelaere-Canivet, J.-F. Spindler, S. Perrio, P. Beslin, Tetrahedron
[12] For representative examples, see: a) L. Rout, T. K. Sen, T. Punniyamurthy,
1,3-Bis(diphenylphosphano)cyclopentadienyl
lithium
(13.17 g,
30 mmol) in THF (200 mL) was added to a suspension of FeCl2
(1.98 g, 15 mmol) in THF (70 mL) at 208C. After 4 h at reflux, the re-
action mixture was quickly filtered through a 2 cm pad of silica,
and the resulting filtrate was evaporated under vacuum. The oil
was purified by column chromatography on a silica gel with tolu-
ene/hexane (1:1) to give an orange solution. The solvent was
evaporated and crystallization in hot ethanol was conducted to
yield L7 as a bright-orange solid, which was air-stable for months
1
(5.75 g, 6.23 mmol, 42%). M.p. 1808C; H NMR (C6D6): d=7.03–7.50
(m, 40H; Ph), 4.40 (s, 2H; Cp), 3.97 ppm (s, 4H; Cp); 31P NMR
(C6D6): d=À22.46 ppm (s); 13C NMR (C6D6): d=139.3 (m; i-Ph),
134.0 (pt, JPC+P’C =30 Hz; o’’’-Ph), 133.7 (pt, JPC+P’C =60 Hz; o’’-Ph),
133.3 (pt, JPC+P’C =60 Hz; o’-Ph), 133.1 (pt, JPC+P’C =30 Hz; o-Ph),
128.5 (pd, JPC+P’C =23 Hz; m-Ph), 128.2 (pt, JPC+P’C =7 Hz; p-Ph), 83.0
&
&
Chem. Eur. J. 2014, 20, 1 – 12
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ꢁ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ÝÝ These are not the final page numbers!