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and dry deoxygenated solvents. Tetrahydrofuran, diethyl ether, tol-
uene, and pentane were purified on an MBraun SPS-800 Solvent
Purifying System. Nuclear magnetic resonance spectra were record-
ed on a Bruker Advance 300 MHz spectrometer operating at
uene to about 2 mL afforded complex 3 as dark red crystals after
a week at room temperature. When those crystals were dried
under reduced pressure for a few hours and taken back up in C D ,
6
6
partial hydrolysis to the neutral ligand (Ph PS) CH took place. Se-
2
2
2
1
13
31
1
3
00 MHz for H, 75.5 MHz for C, and 121.5 MHz for P. Solvent
lected data obtained from non-dried crystals (for H NMR spectrum,
1
peaks are used as internal references relative to Me Si for H (C D ;
see the Supporting Information, showing the lack of CH signal for
4
6
6
2
1
3
1
d=7.16 ppm) and C (C D ; d=128.1 ppm) chemical shifts (ppm);
neutral ligand at 3.88 pm): H NMR (300 MHz, C D ) d=7.35–7.43
6
6
6
6
3
1
P chemical shifts are relative to a 85% H PO external reference.
(m, 8H, Hortho), 6.86–6.91 (m, 4H, Hpara), 6.72–6.78 ppm (m, 8H,
3
4
31
1
Coupling constants are given in hertz. The following abbreviations
are used: s=singlet; d=doublet; t=triplet; m=multiplet; vt=vir-
tual triplet. Elemental analyses were performed by the in-house
service of Laboratoire de Chimie de Coordination (205, route de
Narbonne, 31077 Toulouse, France) on a PerkinElmer 2400 Series II
Hmeta); P{ H} NMR (121.5 MHz, C D ): d=5.5 ppm (s).
6 6
Compound 5: Route A: To a solution of 2 (0.02 mmol) in toluene
0.65 mL) in an NMR tube was added benzophenone (19 mg,
.1 mmol, 5 equiv) at room temperature. The resulting solution
was heated at 708C for 10 days. Completion of the reaction was
(
0
[18]
[11]
system. [TiCl (thf) ] and solutions of dianion Li (SCS) 1 were
31
1
4
2
2
checked by P{ H} NMR spectroscopy. Spectroscopic data were in
prepared according to literature procedures. Phenyl isocyanate
was degassed prior to use. All other reagents and chemicals were
obtained commercially and used as received.
[3d]
accordance with the literature. Route B To a solution of complex
3
(0.052 mmol) in toluene (0.65 mL) in an NMR tube was added
benzophenone (47 mg, 0.26 mmol, 5 equiv) at room temperature.
The resulting solution was heated at 708C for 4 days. Completion
31
1
X-ray crystallography
of the reaction was checked by P{ H} spectroscopy.
Compound 6: Route A: To a solution of complex 2 (0.032 mmol) in
toluene (1 mL) in an NMR tube was added 9-anthracenecarboxal-
dehyde (6.5 mg, 0.032 mmol, 1 equiv) at room temperature. After
The crystal data of compounds 2a, 2b, 3a, 4, 8a, and 9 were col-
lected on a Bruker-AXS kappa APEX II diffractometer (2a, 2b, and
4
) and on a Bruker-AXS Quazar APEX II diffractometer using a 30 W
air-cooled microfocus source (ImS) with focusing multilayer optics
3a, 8a and 9) with MoKa radiation (wavelength=0.71073 ꢂ) by
31
1
9
0 min, completion of the reaction was checked by P{ H} NMR
spectroscopy. Spectroscopic data were in accordance with the lit-
(
[3d]
erature. Route B: To a solution of complex 3 (0.048 mmol) in tol-
using phi- and omega-scans. Crystals were mounted in inert oil
and crystal structure determinations were effected at 150 K (2a,
uene (0.6 mL) in an NMR tube was added 9-anthracenecarboxalde-
hyde (10 mg, 0.048 mmol, 1 equiv) at room temperature. After
2
b, and 4) or at 193 K (3a, 8a, and 9). The structures were solved
31
1
1
5 min, completion of the reaction was checked by P{ H} NMR
by direct methods, using SHELXS-97 and refined using the least-
2
[19]
spectroscopy.
squares method on F . All non-hydrogen atoms were refined ani-
sotropically. All hydrogen atoms were assigned to idealized geo-
metric positions and included in structure factors calculations.
Crystallographic data (excluding structure factors) have been de-
posited with the Cambridge Crystallographic Data Centre as sup-
plementary publication:
Compound 8a: To a solution of dianion 1 (0.48 mmol) in toluene
(
7.5 mL) was added of [TiCl (thf) ] (240 mg, 0.72 mmol, 1.5 equiv) at
4 2
room temperature. The resulting solution was stirred for 12 h at
room temperature and centrifuged to eliminate LiCl. The carbene
was dosed with PPh (ca. 10 mg) as an internal standard and then
3
two equivalents of DCC (198 mg, 0.96 mmol) were added at room
temperature. The resulting solution was stirred for 8 h and flash
chromatography through an alumina column (toluene) afforded
CCDC-1005314 (2a), CCDC-1005315 (2b), CCDC-1005316 (3a),
CCDC-1005317 (4), CCDC-1005318 (8a), and CCDC-1005319 (9)
contain the supplementary crystallographic data for this paper.
These data can be obtained free of charge from The Cambridge
Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_re-
quest/cif.
8
a (139 mg, 0,25 mmol, 52%) as a white solid. Selected data:
1
H NMR (300 MHz, C D ): d=8.25–8.17 (m, 8H, Hortho), 6.97–6.91 (m,
6
6
1
1
2H, Hmeta +Hpara), 2.98 ppm (tt, J = 9.6 Hz, J =3.8 Hz, 1H, CHipso),
eq ax
13
1
.46–0.71 (m, 10H, HCy); C{ H} NMR (75 MHz, C D ): d=157.4 (t,
6 6
2
1
JC,P =5.8 Hz, P C=CN), 134.0 (d, JC,P =90.5 Hz, ipso-PhÀCH), 133.1
2
Syntheses
3
(
vt, JC,P =5.6 Hz, m-PhÀCH), 131.2 (s, p-PhÀCH), 128.0 (pseudo-t,
3
1
JC,P =6.5 Hz, o-PhÀCH), 59.5 (s, C ), 53.3 (t, J =70.6 Hz, P C=CN),
Complex 2: To a solution of dianion 1 (0.32 mmol) in toluene
Cy
C,P
1
2
3
1
3
3.3 (s, C ), 25.1 (s, C ), 24.0 ppm (s, C ); P{ H} NMR (121.5 MHz,
(
5 mL) was added [TiCl (thf) ] (53 mg, 0.16 mmol, 0.5 equiv) at
Cy
Cy
Cy
4
2
C D ): d=41.6 ppm (s); elemental analysis calcd (%) for
room temperature. The solution instantaneously turned red and
then brown. The resulting solution was stirred for 12 h at room
temperature and LiCl salt was eliminated via centrifugation. Evapo-
ration of the solvents finally gave the desired product as an
orange powder (130 mg, 86% yield). Crystals suitable for X-ray
analysis were obtained by diffusion of pentane into a concentrated
6
6
C H NP S : C 69.17, H 5.62, N 2.52; found: C 68.97, H 5.53, N 2.41.
32 31
2 2
Compound 8b: To a solution of complex 3 (0.048 mmol) in toluene
(0.6 mL) in an NMR tube was added phenyl isocyanate (10 mL,
0.096 mmol, 2 equiv) at room temperature. After 15 min, comple-
31
1
tion of the reaction was checked by P{ H} NMR. Selected data:
1
31
1
solution of the complex in toluene. Selected data: H NMR
P{ H} NMR (121.5 MHz, toluene): d=41.4 (s).
(
300 MHz, C D ): d=7.79–7.72 (m, 16H), 6.93–6.85 ppm (m, 24H);
6 6
1
3
1
C{ H} NMR (75 MHz, C D ): d=149.6 (pseudo-t, Cipso), 137.6 (dd,
6
6
1
Acknowledgements
JPC =83 Hz, JPC =4 Hz, Cipso), 131.8 (pseudo-t, CH), 131.6 (pseudo-t,
31
1
CH), 130.8 ppm (pseudo-t, CH); P{ H} NMR (121.5 MHz, C D ): d=
6
6
1
4
9 ppm (s); elemental analysis calcd (%) for C H P S Ti: C 63.83, H
.29; found: C 63.50, H, 4.02.
M. L. thanks MESR and H. H. thanks the Ecole Polytechnique
for their Ph.D. fellowships.
50
40 4 4
Complex 3: To a solution of dianion 1 (0.32 mmol) in toluene
5 mL) was added [TiCl (thf) ] (160 mg, 0.48 mmol, 1.5 equiv) at
(
4
2
Keywords: carbene ligands · density functional calculations ·
geminal dianions · reaction mechanisms · titanium
room temperature. The resulting solution was stirred for 12 h at
room temperature and centrifuged in order to eliminate LiCl and
the excess of [TiCl (thf) ]. Concentration of the crude mixture in tol-
4
2
Chem. Eur. J. 2014, 20, 16995 – 17003
17002
ꢁ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Lafage, Mathieu
