Multicomponent synthesis of unsymmetrical unsaturated N-heterocyclic carbene precursors and their related transition-metal complexes

Article abstract of DOI:10.1002/anie.201308873

A low-cost, modular, and easily scalable multicomponent procedure affording access in good yields and excellent selectivity (up to 93 %) to a wide range of (a)chiral unsymmetrical 1-aryl-3-cycloalkyl-imidazolium salts is disclosed. Electronic and steric properties of the corresponding unsymmetrical unsaturated N-heterocyclic carbene (U₂-NHC) ligands were evaluated and evidenced strong electron donor ability, high steric discrimination, and modular steric demand. A low-cost, modular, and easily scalable multicomponent procedure, affording access to a wide range of (a)chiral unsymmetrical 1-aryl-3-cycloalkyl- imidazolium salts in good yields and excellent selectivities, is disclosed. Electronic and steric properties of the corresponding unsymmetrical unsaturated N-heterocyclic carbene (U₂-NHC) ligands were evaluated and evidenced strong electron-donor ability, high steric discrimination, and modular steric demand. Copyright

Full text of DOI:10.1002/anie.201308873

Supporting Information
ꢀ
Wiley-VCH 2013
69451 Weinheim, Germany
Multicomponent Synthesis of Unsymmetrical Unsaturated N-
Heterocyclic Carbene Precursors and Their Related Transition-Metal
Complexes**
Pierre Queval, Claire Jahier, Mathieu Rouen, Isabelle Artur, Jean-Christophe Legeay,
Laura Falivene, Loic Toupet, Christophe Crꢀvisy, Luigi Cavallo, Olivier Baslꢀ,* and
Marc Mauduit*
anie_201308873_sm_miscellaneous_information.pdf

Contents
1
2
. General ................................................................................................................................ 2
. Synthesis procedures and analytical data ........................................................................... 3
2
.1. Imidazolium salts........................................................................................................... 3
2
2
.1.a. Chloride imidazolium salts 1a-k-Cl......................................................................... 3
.1.b. Tetrafluoroborate imidazolium salts 1a-i-BF ......................................................... 6
4
2
.2. Metallated complexes.................................................................................................... 8
2
2
2
2
2
2
2
.2.a. Iridium complexes 7a-e........................................................................................... 8
.2.b. Rhodium complexes 8a-b..................................................................................... 10
.2.c. Silver complexes 9a-d .......................................................................................... 10
.2.d. Copper complexes 10a-b ..................................................................................... 12
.2.e. Gold complexes 11a-b.......................................................................................... 12
.2.f. Palladium complexes 12a-c................................................................................... 13
.2.g. Iridium CO complexes 13a-e ................................................................................ 14
3
. NMR spectra...................................................................................................................... 16
3
3
3
3
3
3
3
3
3
3
.1. NMR spectra of selectivities for the synthesis of imidazolium salts ............................ 16
.2. Chloride imidazolium salts........................................................................................... 21
.3. Tetrafluoroborate imidazolium salts ............................................................................ 32
.4. Iridium complexes ....................................................................................................... 44
.5. Rhodium complexes.................................................................................................... 49
.6. Silver complexes ......................................................................................................... 51
.7. Copper complexes ...................................................................................................... 55
.8. Gold complexes........................................................................................................... 57
.9. Palladium complexes .................................................................................................. 59
.10. Iridium CO complexes............................................................................................... 63
3
3
.10.1. NMR spectra....................................................................................................... 63
.10.2. IR spectra (TEP calculations) ............................................................................. 68
4
. X-ray data .......................................................................................................................... 71
4
4
4
4
4
4
4
.1. Imidazolium salts......................................................................................................... 71
.2. Iridium complexes ....................................................................................................... 86
.3. Rhodium complexes.................................................................................................... 92
.4. Silver complexe........................................................................................................... 95
.5. Copper complexe ........................................................................................................ 96
.6. Gold complexes........................................................................................................... 98
.7. Palladium complexes ................................................................................................ 101

1
. General
All the reactions were carried out under inert atmosphere (argon). Dichloromethane was
dried over calcium hydride overnight then distilled priori to use. Toluene and THF were
distilled over sodium/benzophenone priori to use. All commercial chemicals were used as
received unless otherwise noticed.
1
11
13
19
H (400 MHz), B (128 MHz), C (100 MHz), F (376 MHz) NMR spectra were recorded on
1
a Bruker ARX400 spectrometer with complete proton decoupling for nucleus other than H.
1
13
H and C chemical shifts are reported in parts per million with the solvent resonance as the
1
13
1
13
internal standard (CDCl
3
, H: δ 7.26 ppm, C: δ 77.16 ppm; CD
2
Cl
2
, H: δ 5.32 ppm, C:
.Et O (δ = 0.0 ppm)
as the internal standard; F chemical shifts are reported in parts per millions with CFCl (δ =
.0 ppm) as the internal standard. Coupling constants are reported in Hertz (Hz).
1
1
5
3.8 ppm); B chemical shifts are reported in parts per millions with BF
3
2
1
9
3
0
Abbreviations are used as follows: s = singlet, d = doublet, t = triplet, q = quadruplet, qi =
quintet, sep = septet, m = multiplet, br = broad. High resolution mass spectroscopy (HMRS)
analyses were performed at the Centre Régional de Mesures Physiques de l’Ouest
(
CRMPO), Université de Rennes 1. Melting points were measured on a Stuart Melting Point
Apparatus SMP3 and are uncorrected. Optical rotations were recorded on a Perkin Elmer
41 polarimeter. Elemental Analysis (Anal. Calcd.) were performed at Service d'Analyse
3
Elémentaire, COBRA, IRCOF, Mont Saint Aignan (France).
2
ꢀ

2
. Synthesis procedures and analytical data
.1. Imidazolium salts
.1.a. Chloride imidazolium salts 1a-k-Cl
2
2
General procedure for the synthesis of 3-cycloalkyl-1-mesitylimidazolium chloride 1a-
f-Cl and 1j-k-Cl. The reaction was performed in open vessel under air atmosphere. In a
round-bottomed flask were placed 2,4,6-trimethylaniline (10 mmol, 1.0 equiv.),
cycloalkylamine (10 mmol, 1.0 equiv.) and acetic acid (45 mmol, 4.5 equiv.) then the mixture
was heated at 40 °C for 5 min (mixture A). In another round-bottomed flask were placed
glyoxal (10 mmol, 1.0 equiv., 40 % wt in aqueous solution), formaldehyde (10 mmol, 1.0
equiv., 37 % wt in aqueous solution) and acetic acid (45 mmol, 4.5 equiv.) then the mixture
was heated at 40 °C for 5 min (mixture B). At 40 °C, mixture B was added to mixture A and
the resulting mixture was stirred at 40 °C for 10 min then cooled down to room temperature
(
the selectivity of the reaction was calculated by integration of characteristic signals of the
1
different compounds on the H NMR spectrum of the crude product (see spectra below), it
could be necessary to add few drops of water in the sample to displace the residual signal of
3
CH COOH). Dichloromethane (100 mL) was added and the organic layer was successively
washed with water (200 mL) then brine (2 x 100 mL). The combined aqueous layers were
extracted with dichloromethane (100 mL). The combined organic layers were dried over
magnesium sulfate, filtered and the volatiles were removed under reduced pressure. Ethyl
acetate (20 mL) was added to the crude mixture and the resulting suspension was heated to
reflux then cooled down to 0 °C. The solid was filtered and washed with ethyl acetate (3 x 10
mL) then dried under reduced pressure to afford the expected unsymmetrical chloride
imidazolium salt as a pale white solid.
General procedure for the synthesis of 3-cycloalkyl-1-(2,6-diisopropylphenyl) chloride
1
g-i-Cl. The compounds 1g-i-Cl were prepared following the procedure described above,
except that 2,4,6-trimethylaniline was replaced by 2,6-diisopropylaniline (10 mmol, 1.0
equiv.) and run at 90 °C instead of 40°C.
3
-cyclopentyl-1-mesitylimidazolium chloride 1a-Cl was
prepared from cyclopentylamine (0.99 mL, 10 mmol), 2,4,6-
trimethylaniline (1.41 mL, 10 mmol), glyoxal (1.14 mL, 10 mmol,
Cl
N
N
4
3
0 % wt in aqueous solution), formaldehyde (0.74 mL, 10 mmol,
7 % wt in aqueous solution) and acetic acid (5.1 mL, 90 mmol)
at 40 °C (selectivity 1a-OAc/bisC5-OAc/bisMes-OAc = 93/3/4,
see spectrum below). 1a-Cl was obtained as a pale white solid (1.59 g, 55 %, mp = 169 °C).
1
H-NMR (400 MHz, CDCl
3
) δ 10.36 (s, 1H), 7.94 (br. s, 1H), 7.20 (br. s, 1H), 6.83 (s, 2H),
5
4
1
2
.34-5.28 (m, 1H), 2.55 (s, 1H), 2.31-2.28 (m, 2H), 2.18 (s, 3H), 1.91 (s, 6H), 1.88-1.79 (m,
1
3
1
H), 1.65-1.62 (m, 2H); C{ H}-NMR (100 MHz, CDCl
23.6, 121.0, 61.2, 33.4, 23.4, 20.7, 17.3; HRMS (ESI) calcd for C17
55.1861, found: m/z 255.1861 (0 ppm). Single-crystals of 1a-Cl were obtained by slow
3
) δ 140.6, 137.3, 133.9, 130.6, 129.4,
+
+
23 2
H N ([M − Cl] ): m/z
evaporation of a saturated solution in ethyl acetate. CCDC 867551.
3
-cyclohexyl-1-mesitylimidazolium chloride 1b-Cl was
Cl
prepared from cyclohexylamine (1.14 mL, 10 mmol), 2,4,6-
trimethylaniline (1.41 mL, 10 mmol), glyoxal (1.14 mL, 10 mmol,
N
N
4
3
0 % wt in aqueous solution), formaldehyde (0.74 mL, 10 mmol,
7 % wt in aqueous solution) and acetic acid (5.1 mL, 90 mmol)
at 40 °C (selectivity 1b-OAc/bisC6-OAc/bisMes-OAc = 90/8/2,
see spectrum below). 1b-Cl was obtained as a pale white solid (2.27 g, 74 %, mp = 258 °C).
1
H-NMR (400 MHz, CDCl
3
) δ 10.83-10.81 (m, 1H), 7.80-7.78 (m, 1H), 7.18-7.16 (m, 1H),
6
.97-6.95 (m, 2H), 5.11-5.02 (m, 1H), 2.30 (s, 3H), 2.29-2.24 (m, 2H), 2.04 (s, 6H), 1.93-1.69
1
3
1
(
3
m, 5H), 1.62-1.49 (m, 2H), 1.34-1.21 (m, 1H); C{ H}-NMR (100 MHz, CDCl ) δ 140.8,
3
ꢀ

1
37.5, 134.1, 131.0, 129.7, 123.3, 121.0, 59.9, 33.6, 24.9, 24.5, 21.0, 17.5; HRMS (ESI)
+
+
calcd for C18
H
25
N
2
([M − Cl] ): m/z 269.2018, found: m/z 269.2019 (0 ppm).
3
-cycloheptyl-1-mesitylimidazolium chloride 1c-Cl was
prepared from cycloheptylamine (1.27 mL, 10 mmol), 2,4,6-
trimethylaniline (1.41 mL, 10 mmol), glyoxal (1.14 mL, 10
mmol, 40 % wt in aqueous solution), formaldehyde (0.74 mL,
Cl
N
N
1
9
0 mmol, 37 % wt in aqueous solution) and acetic acid (5.1 mL,
0 mmol) at 40 °C (selectivity 1c-OAc/bisC7-OAc/bisMes-
OAc = 93/5/3, see spectrum below). 1c-Cl was obtained as a pale white solid (2.06 g, 65 %,
1
mp = 249 °C). H-NMR (400 MHz, CDCl
3
) δ 10.55-10.51 (m, 1H), 7.94-7.90 (m, 1H), 7.21-
7
1
.19 (m, 1H), 6.89-6.86 (m, 2H), 5.21-5.12 (m, 1H), 2.23 (s, 3H), 2.20-2.11 (m, 2H), 2.09-
.98 (m, 2H), 1.96 (s, 6H), 1.77-1.67 (m, 2H), 1.65-1.50 (m, 6H); C{ H}-NMR (100 MHz,
1
3
1
CDCl
3
) δ 140.8, 137.3, 134.1, 130.9, 129.7, 123.5, 120.8, 62.2, 35.9, 27.1, 24.0, 21.0, 17.5;
+
+
HRMS (ESI) calcd for C19
H
27
N
2
([M − Cl] ): m/z 283.2174, found: m/z 283.2173 (0 ppm).
3
-cyclooctyl-1-mesitylimidazolium chloride 1d-Cl was
Cl
prepared from cyclooctylamine (1.37 mL, 10 mmol), 2,4,6-
trimethylaniline (1.41 mL, 10 mmol), glyoxal (1.14 mL, 10
mmol, 40 % wt in aqueous solution), formaldehyde (0.74 mL,
N
N
1
0 mmol, 37 % wt in aqueous solution) and acetic acid (5.1
mL, 90 mmol) at 40 °C (selectivity 1d-OAc/bisC8-OAc/bisMes-OAc = 93/5/3, see spectrum
1
below). 1d-Cl was obtained as a pale white solid (2.34 g, 70 %, mp = 201 °C). H-NMR (400
MHz, CDCl
3
) δ 10.93-10.91 (m, 1H), 7.70-7.68 (m, 1H), 7.17-7.15 (m, 1H), 6.97-6.94 (m, 2H),
3
5
1
1
−
.45 (qi, JH-H = 6.8 Hz, 1H), 2.30 (s, 3H), 2.18-2.11 (m, 4H), 2.05 (s, 6H), 1.81-1.74 (m, 4H),
.71-1.55 (m, 6H); C{ H}-NMR (100 MHz, CDCl ) δ 141.1, 138.3, 134.3, 131.0, 129.9,
3
1
3
1
+
23.2, 120.2, 61.4, 34.0, 26.5, 25.7, 24.0, 21.2, 17.7; HRMS (ESI) calcd for C20
H
29
N
2
([M
+
Cl] ): m/z 297.2331, found: m/z 297.2332 (0 ppm).
3
-cyclododecyl-1-mesitylimidazolium chloride 1e-Cl was
prepared from cyclododecylamine (367 mg, 2 mmol), 2,4,6-
trimethylaniline (0.28 mL, 2 mmol), glyoxal (0.23 mL, 2
mmol, 40 % wt in aqueous solution), formaldehyde (0.15 mL,
Cl
N
N
2
mmol, 37 % wt in aqueous solution) and acetic acid (1.03
mL, 18 mmol) at 40 °C (selectivity 1e-OAc/bisC12-
OAc/bisMes-OAc = 93/5/3, see spectrum below). 1e-Cl was
1
obtained as a pale white solid (625 mg, 80 %, mp = 258 °C). H-NMR (400 MHz, CDCl
3
): δ
3
3
1
0.69 (s, 1H), 7.92 (t, JH-H = 2.0 Hz, 1H), 7.24 (s, JH-H = 2.0 Hz, 1H), 6.82 (s, 2H), 5.01-4.98
m, 1H), 2.17 (s, 3H), 2.12-2.07 (m, 2H), 1.91 (s, 6H), 1.44-1.14 (m, 18H); C{ H}-NMR (100
1
3
1
(
MHz, CDCl ) δ 140.4, 137.6, 133.7, 130.6, 129.3, 123.3, 121.3, 58.5, 30.1, 23.4, 23.2, 22.9,
3
+
+
2
3
1.0, 20.7, 17.2; HRMS (ESI) calcd for C24
H
37
N
2
([M − Cl] ): m/z 353.2957, found: m/z
53.2956 (0 ppm). Single-crystals of 1e-Cl were obtained by slow evaporation of a saturated
solution in ethyl acetate. CCDC 933498.
3
-adamantyl-1-mesitylimidazolium chloride 1f-Cl was
prepared from 1-adamantylamine (1.51 g, 10 mmol), 2,4,6-
trimethylaniline (1.41 mL, 10 mmol), glyoxal (1.14 mL, 10
mmol, 40 % wt in aqueous solution), formaldehyde (0.74 mL,
Cl
N
N
1
0 mmol, 37 % wt in aqueous solution) and acetic acid (5.14
mL, 90 mmol) at 40 °C (selectivity 1f-OAc/bisAdamantyl-
OAc/bisMes-OAc = 88/4/8, see spectrum below). 1f-Cl was obtained as a pale white solid
1
(
1.70 g, 48 %, mp = 299 °C). H-NMR (400 MHz, CDCl
3
): δ 10.58-10.54 (m, 1H), 8.05-8.02
(
3
1
m, 1H), 7.26-7.23 (m, 1H), 6.94-6.90 (m, 2H), 2.38-2.33 (m, 6H), 2.29-2.25 (m, 3H), 2.26 (s,
H), 2.04 (s, 6H), 1.84-1.69 (m, 6H); C{ H}-NMR (100 MHz, CDCl ) δ 140.9, 136.9, 134.2,
3
31.2, 129.8, 123.3, 119.8, 61.6, 42.8, 35.3, 29.6, 21.1, 17.7; HRMS (ESI) calcd for
1
3
1
4
ꢀ

+
+
C
22
H
29
N
2
([M − Cl] ): m/z 321.2331, found: m/z 321.2331 (0 ppm). Single-crystals of 1f-Cl
were obtained by slow evaporation of a saturated solution in ethyl acetate. CCDC 961393.
3
1
2
-cyclopropyl-1-(2,6-diisopropylphenyl)imidazolium chloride
g-Cl was prepared from cyclopropylamine (2.8 mL, 40.0 mmol),
,6-diisopropylaniline (7.5 mL, 40.0 mmol), glyoxal (4.6 mL, 40.0
Cl
N
N
mmol, 40 % wt in aqueous solution), formaldehyde (3.0 mL, 40.0
mmol, 37 % wt in aqueous solution) and citric acid (23.0 g, 120
mmol) at 90 °C (because of the possible instability (degradation) of
bis(cyclopropyl)imidazolium salt in the reaction conditions the
selectivity could not be determined). 1g-Cl was obtained as a pale
pink solid (2.56 g, 21 %, mp = 161 °C) after precipitation with ethyl acetate/diethyl ether 1/15
1
3
(
200 mL). H-NMR (400 MHz, CDCl
3
) δ 10.82-10.80 (m, 1H), 7.70-7.68 (m, 1H), 7.52 (t, JH-H
2
3
=
2
1
1
−
7.8 Hz, 1H), 7.30 (d, JH-H = 7.8 Hz, 2H), 7.14-7.14 (m, 1H), 4.67 (qi, JH-H = 5.6 Hz, 1H),
3
3
.30 (sep, JH-H = 6.8 Hz, 2H), 1.28 (s, 2H), 1.37-1.35 (m, 2H), 1.26 (d, JH-H = 6.8 Hz, 6H),
3
13
1
.13 (d, JH-H = 6.8 Hz, 6H); C{ H}-NMR (100 MHz, CDCl
24.7, 124.5, 121.3, 61.6, 33.8, 28.7, 24.3, 24.1, 24.0; HRMS (ESI) calcd for C18
Cl] ): m/z 269.2018, found: m/z 269.2017 (0 ppm). Single-crystals of 1g-Cl were obtained
3
) δ 145.3, 138.02, 131.6, 130.4,
+
H
25
N
2
([M
+
by slow evaporation of a saturated solution in ethyl acetate/dichloromethane. CCDC 961639.
3
-cyclopentyl-1-(2,6-diisopropylphenyl)imidazolium chloride
Cl
1h-Cl was prepared from cyclopentylamine (0.99 mL, 10.0
mmol), 2,6-diisopropylaniline (1.88 mL, 10.0 mmol), glyoxal (1.14
mL, 10.0 mmol, 40 % wt in aqueous solution), formaldehyde
N
N
(
0.74 mL, 10.0 mmol, 37 % wt in aqueous solution) and acetic
acid (5.14 mL, 90 mmol) at 90 °C (selectivity 1h-OAc/bisC12-
OAc/bisDipp-OAc = 62/38/0, see spectrum below). 1h-Cl was
obtained as a pale brown solid (0.91 g, 27 %, mp = 186 °C) after precipitation in ethyl
acetate/diethyl ether 1/10 (10 mL) then washes with ethyl acetate/dichloromethane 10/1 (3 x
1
3
2
7
2
6
1
C
0 mL). H-NMR (400 MHz, CDCl
3
) δ 10.65-10.63 (m, 1H), 7.89-7.87 (m, 1H), 7.50 (t, JH-H
=
3
3
.8 Hz, 1H), 7.28 (d, JH-H = 7.8 Hz, 2H), 7.20-7.18 (m, 1H), 5.75 (qi, JH-H = 6.7 Hz, 1H),
.56-2.46 (m, 2H), 2.26 (sep, JH-H = 6.8 Hz, 1H), 2.00-1.86 (m, 6H), 1.23 (d, JH-H = 6.8 Hz,
H), 1.13 (d, JH-H = 6.8 Hz, 6H); C{ H}-NMR (100 MHz, CDCl ) δ 145.3, 138.02, 131.6,
3
3
3
3
13
1
30.4, 124.7, 124.5, 121.3, 61.6, 33.8, 28.7, 24.3, 24.1, 24.0; HRMS (ESI) calcd for
+
+
20
29 2
H N ([M − Cl] ): m/z 297.2331, found: m/z 297.2331 (0 ppm).
3
-cyclododecyl-1-(2,6-diisopropylphenyl)imidazolium
chloride 1i-Cl was prepared from cyclododecylamine (7.15
g, 40.0 mmol), 2,6-diisopropylaniline (7.15 g, 40.0 mmol),
glyoxal (4.6 mL, 40.0 mmol, 40 % wt in aqueous solution),
formaldehyde (3.2 mL, 40.0 mmol, 37 % wt in aqueous
solution) and acetic acid (20.6 mL, 360 mmol) at 90 °C
Cl
N
N
(
selectivity 1i-OAc/bisC12-OAc/bisDipp-OAc = 57/43/0,
see spectrum below). The residual bis-
cyclododecylimidazolium chloride was removed by precipitation in ethyl acetate/diethyl ehter
then the residual cyclododecylammonium chloride was removed by precipitation in diethyl
ether. 1g-Cl was obtained as a pale brown solid (6.21 g, 36 %, mp = 88 °C) after flash
1
chromatography on silica gel (gradient: diethyl ether then ethyl acetate then ethanol). H-
3
3
NMR (400 MHz, CDCl
3
) δ 10.45 (m, 1H), 8.11 (t, JH-H = 1.6 Hz, 1H), 7.42 (t, JH-H = 8.0 Hz,
3
1
4
H), 7.24 (t, JH-H = 2.0 Hz, 1H), 7.20 (s, 1H), 7.18 (s, 1H), 5.28-5.12 (m, 1H), 2.41-2.10 (m,
H), 1.86-1.78 (m, 2H), 1.50-1.27 (m, 18H), 1.11 (d, JH-H = 6.8 Hz, 6H), 1.06 (d, JH-H = 6.8
Hz, 6H); C{ H}-NMR (100 MHz, CDCl ) δ 145.3, 137.9, 131.6, 130.4, 124.5, 121.9, 59.0,
3
0.2, 28.7, 24.4, 23.9, 23.7, 23.2, 21.1; HRMS (ESI) calcd for C27
95.3420, found: m/z 395.3418 (1 ppm).
3
3
1
3
1
+
+
3
3
H
43
N
2
([M − Cl] ): m/z
5
ꢀ

3
-cyclododecyl-1-(3,5-dimethylphenol)imidazolium
chloride 1j-Cl was prepared from cyclododecylamine (1.83
g, 10.0 mmol), 4-hydroxy-2,6-dimethylaniline (1.37 g, 10.0
mmol), glyoxal (1.14 mL, 10.0 mmol, 40 % wt in aqueous
solution), formaldehyde (0.74 mL, 10.0 mmol, 37 % wt in
aqueous solution) and acetic acid (5.14 mL, 90.0 mmol) at
Cl
N
N
HO
4
0 °C (selectivity 1j-OAc/bisC12-OAc/bisMesOH-OAc =
9
1/6/3, see spectrum below). 1j-Cl was obtained as a pale brown solid after purification with
1
ethyl acetate/dichloromethane (4/1, 50 mL) (3.57 g, 91 %, mp = 257 °C). H-NMR (400 MHz,
CDCl /CD OD 4/1): δ 9.76-9.71 (m, 1H), 7.64-7.60 (m, 1H), 7.31-7.28 (m, 1H), 6.61-6.56 (m,
H), 4.86-4.77 (m, 1H), 2.19-2.07 (m, 2H), 1.91-1.78 (m, 2H), 1.88 (s, 6H), 1.55-1.25 (m,
3
3
1
1
1
−
1
3
1
8H); C{ H}-NMR (100 MHz, CDCl
3 3
/CD OD) δ 158.9, 137.1, 135.4, 124.7, 124.5, 121.0,
+
15.9, 59.2, 30.3, 23.8, 23.7, 23.4, 23.2, 21.2, 17.4; HRMS (ESI) calcd for C23
Cl] ): m/z 355.2749, found: m/z 355.2747 (1 ppm). Single-crystals of 1j-Cl were obtained
H
35
N
2
O ([M
+
by slow evaporation of a saturated solution in ethyl acetate. CCDC 945381.
3
-(1R,2S,3S,5R)-isopinocampheyl-1-mesitylimidazolium
Cl
chloride 1k-Cl was prepared from (1S,2S,3S,5R)-(+)-
isopinocampheylamine (307 mg, 2.0 mmol), 2,4,6-
trimethylaniline (0.28 mL, 2.0 mmol), glyoxal (0.23 mL, 2.0
mmol, 40 % wt in aqueous solution), formaldehyde (0.15 mL,
N
N
2
.0 mmol, 37 % wt in aqueous solution) and acetic acid (1.03 mL, 18.0 mmol) at 40 °C
(
selectivity 1k-Cl/bisIsopino-Cl/bisMes-Cl = 92/3.5/4.5, see spectrum below). 1k-Cl was
1
obtained as a pale white solid (384 mg, 53 %, mp = 265 °C). H-NMR (400 MHz, CDCl
3
) δ
1
3
2
1.19-11.17 (m, 1H), 7.69-7.66 (m, 1H), 7.26-7.24 (m, 1H), 6.97 (s, 2H), 5.97-5.88 (m, 1H),
.05-2.95 (m, 1H), 2.66-2.56 (m, 1H), 2.32 (s, 3H), 2.32-2.23 (m, 1H), 2.15-2.10 (m, 1H),
3
.10 (s, 3H), 2.05 (s, 3H), 2.02-1.94 (m, 2H), 1.90 (br. s, 1H), 1.28 (s, 3H), 1.21 (d, JH-H = 6.8
1
3
1
Hz, 3H), 1.20 (s, 3H), 1.15-1.11 (m, 1H); C{ H}-NMR (100 MHz, CDCl
3
) δ 141.2, 139.8,
1
2
34.4, 134.1, 131.0, 130.0, 129.9, 124.1, 119.8, 59.5, 47.6, 45.6, 41.6, 39.2, 36.6, 35.7, 28.2,
+
+
3.6, 21.2, 20.0, 17.9, 17.6; HRMS (ESI) calcd for C22
H
31
N
2
([M − Cl] ): m/z 323.8487,
2
0
found: m/z 323.8485 (1 ppm); [α]
D 3
= + 20.0 (c = 1.00 (CHCl )).
2
.1.b. Tetrafluoroborate imidazolium salts 1a-i-BF
4
General procedure for the synthesis of tetrafluoroborate imidazoliums salts 1a-i-BF
4
.
The reactions were performed in open vessel under air atmosphere. In a round-bottomed
flask were placed chloride imidazolium salt (0.50 mmol, 1.0 equiv.) and dichloromethane (2.5
mL). Potassium tetrafluoroborate (0.50 mmol, 1.0 equiv.) was added and the mixture was
stirred at room temperature for 1 h. The crude mixture was filtered on a Celite bed then the
solvent was removed under reduced pressure. The expected tetrafluoroborate imidazolium
salt was obtained as a pale white solid.
3
-cyclopentyl-1-mesitylimidazolium tetrafluoroborate 1a-BF
4
was prepared from 1a-Cl (872 mg, 3 mmol), potassium
tetrafluoroborate (378 mg, 3 mmol) and dichloromethane (12
BF4
N
N
mL). 1a-BF
mp = 96 °C). H-NMR (400 MHz, CDCl
1
4
was obtained as a pale white solid (972 mg, 94 %,
1
3
3
) δ 8.82 (t, JH-H = 1.7 Hz,
H), 7.70 (t, JH-H = 1.7 Hz, 1H), 7.24 (t, J = 1.7 Hz, 1H), 6.97 (s,
H), 5.03 (qi, JH-H = 7.5 Hz, 1H), 2.46-2.35 (m, 2H), 2.32 (s, 3H), 2.00 (s, 6H), 1.97-1.87 (m,
H), 1.83-1.71 (m, 2H); C{ H}-NMR (100 MHz, CDCl ) δ 141.3, 136.6, 134.4, 130.8, 129.9,
3
3
24.3, 121.4, 62.0, 35.6, 24.0, 21.2, 17.3; B-NMR (128 MHz, CDCl ) δ -1.03; F-NMR (376
3
3
2
4
1
1
3
1
1
1
19
6
ꢀ

MHz, CDCl
3 4
) δ -152.1. Single-crystals of 1a-BF were obtained by slow evaporation of a
saturated solution in ethyl acetate. CCDC 904639.
3
-cyclohexyl-1-mesitylimidazolium tetrafluoroborate 1b-
BF was prepared from 1b-Cl (152 mg, 0.50 mmol), potassium
tetrafluoroborate (63 mg, 0.50 mmol) and dichloromethane (2.5
BF4
4
N
N
mL). 1b-BF
4
was obtained as a pale white solid (177 mg, 99
1
3
%
, mp = 170 °C). H-NMR (400 MHz, CDCl
3
) δ 8.85 (t, JH-H
=
3
3
1
.8 Hz, 1H), 7.73 (t, JH-H = 1.8 Hz, 1H), 7.22 (t, JH-H = 1.8 Hz,
1
H), 6.97 (s, 2H), 4.64-4.53 (m, 1H), 2.32 (s, 3H), 2.27-2.18 (m, 2H), 2.00 (s, 6H), 1.95-1.85
1
3
1
(
m, 2H), 1.83-1.66 (m, 3H), 1.58-144 (m, 2H), 1.34-1.21 (m, 1H); C{ H}-NMR (100 MHz,
CDCl ) δ 141.3, 135.7, 134.4, 130.9, 129.9, 123.9, 121.1, 60.5, 33.6, 25.0, 24.7, 21.2, 17.3;
3
1
1
19
B-NMR (128 MHz, CDCl
3 3
) δ -0.99; F-NMR (376 MHz, CDCl ) δ -151.7. Single-crystals of
1
b-BF were obtained by slow evaporation of a saturated solution in ethyl acetate. CCDC
4
8
62361.
3
-cycloheptyl-1-mesitylimidazolium tetrafluoroborate 1c-
BF was prepared from 1c-Cl (159 mg, 0.50 mmol), potassium
tetrafluoroborate (63 mg, 0.50 mmol) and dichloromethane (2.5
BF4
4
N
N
mL). 1c-BF
mp = 185 °C). H-NMR (400 MHz, CDCl
Hz, 1H), 7.72 (t, JH-H = 1.8 Hz, 1H), 7.22 (t, JH-H = 1.8 Hz, 1H),
4
was obtained as a pale white solid (182 mg, 98 %,
1
3
3
) δ 8.85 (t, JH-H = 1.8
3
3
6
6
1
.97 (s, 2H), 4.81-4.71 (m, 1H), 2.31 (s, 3H), 2.24-2.14 (m, 2H), 2.06-1.94 (m, 2H), 1.99 (s,
1
3
1
H), 1.84-1.76 (m, 2H), 1.71-1.58 (m, 6H); C{ H}-NMR (100 MHz, CDCl
34.4, 130.9, 129.8, 124.1, 121.1, 62.8, 36.0, 27.0, 24.1, 21.2, 17.3; B-NMR (128 MHz,
3
) δ 141.2, 135.5,
1
1
1
9
3 3 4
CDCl ) δ -0.98; F-NMR (376 MHz, CDCl ) δ -151.6. Single-crystals of 1c-BF were obtained
by slow evaporation of a saturated solution in ethyl acetate. CCDC 901079.
3
-cyclooctyl-1-mesitylimidazolium tetrafluoroborate 1d-
BF was prepared from 1d-Cl (166 mg, 0.50 mmol), potassium
tetrafluoroborate (63 mg, 0.50 mmol) and dichloromethane
BF4
4
N
N
(
9
=
2.5 mL). 1d-BF
6 %, mp = 175 °C). H-NMR (400 MHz, CDCl
4
was obtained as a pale white solid (185 mg,
1
3
3
) δ 8.86 (t, JH-H
3
3
1.7 Hz, 1H), 7.70 (t, JH-H = 1.7 Hz, 1H), 7.23 (t, JH-H = 1.7
3
Hz, 1H), 6.97 (br. s, 2H), 4.58 (qi, JH-H = 6.8 Hz, 1H), 2.31 (s, 3H), 2.14-2.07 (m, 4H), 2.00
s, 6H), 1.85-1.74 (m, 2H), 1.74-1.51 (m, 8H); C{ H}-NMR (100 MHz, CDCl
35.5, 134.4, 130.9, 129.9, 124.1, 121.3, 62.1, 33.9, 26.3, 25.5, 23.9, 21.2, 17.3; B-NMR
1
3
1
(
1
(
3
) δ 141.2,
1
1
1
9
128 MHz, CDCl
3 3 4
) δ -0.99; F-NMR (376 MHz, CDCl ) δ -151.6. Single-crystals of 1d-BF
were obtained by slow evaporation of a saturated solution in ethyl acetate. CCDC 901330.
3
-cyclododecyl-1-mesitylimidazolium tetrafluoroborate
1e-BF was prepared from 1e-Cl (194 mg, 0.50 mmol),
potassium tetrafluoroborate (63 mg, 0.50 mmol) and
dichloromethane (2.5 mL). 1e-BF was obtained as a pale
white solid (218 mg, 99 %, mp = 177 °C). H-NMR (400
BF4
4
N
N
4
1
3
3
MHz, CDCl
Hz, 1H), 7.27 (t, JH-H = 1.8 Hz, 1H), 6.96 (s, 2H), 4.79-4.69
m, 1H), 2.31 (s, 3H), 2.17-2.07 (m, 2H), 2.00 (s, 6H), 1.87-
3
) δ 8.86 (t, JH-H = 1.8 Hz, 1H), 7.73 (t, JH-H = 1.8
3
(
1
3
1
1
1
.76 (m, 2H), 1.54-1.22 (m, 18H); C{ H}-NMR (100 MHz, CDCl
30.9, 129.8, 124.2, 121.9, 59.4, 30.2, 23.7, 23.4, 23.4, 23.3, 21.4, 21.2, 17.2; B-NMR (128
MHz, CDCl ) δ -1.03; F-NMR (376 MHz, CDCl ) δ -151.5. Single-crystals of 1e-BF were
3 3 4
3
) δ 141.1, 135.9, 134.4,
1
1
1
9
obtained by slow evaporation of a saturated solution in ethyl acetate. CCDC 862360.
7
ꢀ

3
-cyclododecyl-1-(2,6-diisopropylphenyl)imidazolium te-
trafluoroborate 1i-BF was prepared from 1i-Cl (6.21 g,
4.4 mmol), potassium tetrafluoroborate (1.81 mg, 14.4
mmol) and dichloromethane (100 mL). 1i-BF was obtained
as a pale white solid (6.21 g, 89 %, mp = 131 °C). H-NMR
4
BF4
1
N
N
4
1
(
(
(
3
400 MHz, CDCl ) δ 9.82 (br. s, 1H), 7.97 (s, 1H), 7.47
t, JH-H = 8.0 Hz, 1H), 7.27-7.26 (m, 1H), 7.25 (s, 1H), 7.23
3
s, 1H), 5.05-5.02 (m, 1H), 2.25-2.11 (m, 4H), 1.88-1.80 (m,
3
3
13
1
2
H), 1.51-1.26 (m, 18H), 1.15 (d, JH-H = 6.8 Hz, 6H), 1.11 (d, JH-H = 6.8 Hz, 6H); C{ H}-
NMR (100 MHz, CDCl ) δ 145.4, 137.4, 131.8, 130.4, 124.8, 124.6, 121.8, 59.3, 30.2, 28.8,
4.3, 24.1, 23.9, 23.7, 23.3, 21.2; B-NMR (128 MHz, CDCl
CDCl ) δ -151.8.
3
1
1
19
2
3
) δ -1.00; F-NMR (376 MHz,
3
2
.2. Metallated complexes
.2.a. Iridium complexes 7a-e
2
General procedure for the synthesis of the [(3-cycloalkyl-1-mesityl-imidazol-2-ylidene)-
cyclooctadiene)-iridium chloride] complexes 7a-e. In a flame-dried Schlenk tube were
placed [Ir-µCl-(cod)] (0.088 mmol, 1.0 equiv.), t-BuOK (0.176 mmol, 2.0 equiv.) and THF (5
(
2
mL) under argon atmosphere. The mixture was stirred at room temperature for 10 min then
imidazolium salt (0.158 mmol, 1.8 equiv.) was added and the resulting mixture was stirred for
2
h at room temperature. The mixture was concentrated under reduced pressure then
purified by flash chromatography on silica gel with diethyl ether to afford the desired product
as a yellow solid.
[
-
0
(3-cyclopentyl-1-mesityl-imidazol-2-ylidene)-(cyclooctadiene)
iridium chloride] 7a was prepared from [Ir-µCl-(cod)] (59 mg,
.088 mmol), t-BuOK (20 mg, 0.176 mmol), 3-cyclopentyl-1-
2
N
N
4
mesityl-imidazolium tetrafluoroborate 1a-BF (54 mg, 0.158 mmol)
in THF (5 mL). 7a was obtained as a yellow solid (82 mg, 88 %).
Cl
1
3
Ir
H-NMR (400 MHz, CDCl
br. s, 1H), 6.89 (br. s, 1H), 6.75 (d, JH-H = 2.0 Hz, 1H), 5.97 (qi,
3
): δ 7.06 (d, JH-H = 2.0 Hz, 1H), 7.00
3
(
3
J
H-H = 7.4 Hz, 1H), 4.49-4.43 (m, 1H), 4.34-4.26 (m, 1H), 3.18-
3
.10 (m, 1H), 2.68-2.61 (m, 1H), 2.49-2.40 (m, 1H), 2.35 (s, 3H),
2
.31 (s, 3H), 2.22-2.10 (m, 1H), 2.03-1.92 (m, 1H), 1.89 (s, 3H), 1.87-1.68 (m, 7H), 1.67-1.58
1
3
1
(
3
m, 2H), 1.43-1.29 (m, 2H), 1.14-1.03 (m, 1H); C{ H}-NMR (100 MHz, CDCl ): δ 179.8,
1
3
C
38.6, 137.1, 136.1, 134.4, 129.5, 128.1, 123.5, 117.0, 83.4, 81.9, 62.1, 52.3, 50.0, 35.5,
5.2, 33.3, 31.9, 30.5, 28.2, 25.1, 24.9, 21.2, 19.7, 18.0; HRMS (ASAP) calcd for
3
5
193
+.
+.
25
H
34 Cl IrN
2
([M] ): m/z 590.2040, found: m/z 590.2031 (2 ppm). Single-crystals of 7a
were obtained by slow evaporation of a saturated solution in diethyl ether. CCDC 932347.ꢀ
[
(3-cyclohexyl-1-mesityl-imidazol-2-ylidene)-(cyclooctadiene)
iridium chloride] 7b was prepared from [Ir-µCl-(cod)] (59 mg,
0.088 mmol), t-BuOK (20 mg, 0.176 mmol), 3-cyclohexyl-1-
mesityl-imidazolium tetrafluoroborate 1b-BF (56 mg, 0.158
-
2
N
N
4
mmol) in THF (5 mL). 7b was obtained as a yellow solid (80 mg,
1
3
Cl
84 %). H-NMR (400 MHz, CDCl
3
): δ 7.04 (d, JH-H = 2.0 Hz, 1H),
Ir
3
7
5
2
2
.00 (br. s, 1H), 6.89 (br. s, 1H), 6.73 (d, JH-H = 2.0 Hz, 1H),
.59-5.49 (m, 1H), 4.46-4.35 (m, 2H), 3.13-3.05 (m, 2H), 2.74-
.65 (m, 1H), 2.46-2.39 (m, 1H), 2.35 (s, 3H), 2.31 (s, 3H), 2.17-
.06 (m, 2H), 2.05-1.91 (m, 2H), 1.87 (s, 3H), 1.83-1.74 (m, 2H),
1
3
1
1
.65-1.48 (m, 7H), 1.48-1.34 (m, 2H), 1.29-1.20 (m, 1H), 1.20-1.09 (m, 1H); C{ H}-NMR
(
100 MHz, CDCl
3
): δ 179.2, 138.6, 137.1, 136.1, 134.5, 129.5, 128.1, 123.1, 117.3, 82.8,
8
ꢀ

8
2.4, 60.5, 51.7, 50.3, 35.6, 35.1, 33.3, 32.4, 30.0, 28.7, 26.1, 25.7, 21.2, 19.7, 17.9; Anal.
Calcd. for C26
H
2
34ClIrN : C, 51.85; H, 5.69; N, 4.65. Found: C, 51.53; H, 6.12; N, 4.58.
[
(3-cycloheptyl-1-mesityl-imidazol-2-ylidene)-(cyclooctadi-
ene)-iridium chloride] 7c was prepared from [Ir-µCl-(cod)] (59
mg, 0.088 mmol), t-BuOK (20 mg, 0.176 mmol), 3-cycloheptyl-1-
mesityl-imidazolium tetrafluoroborate 1c-BF (58 mg, 0.158
2
N
N
4
mmol) in THF (5 mL). 7c was obtained as a yellow solid (88 mg,
Cl
1
3
Ir
91 %). H-NMR (400 MHz, CDCl
): δ 7.04 (d, JH-H = 2.0 Hz, 1H),
3
3
6
5
3
.99 (br s, 1H), 6.89 (br. s, 1H), 6.72 (d, JH-H = 2.0 Hz, 1H),
.81-5.72 (m, 1H), 4.48-4.41 (m, 1H), 4.40-4.33 (m, 1H), 3.11-
.05 (m, 1H), 2.75-2.68 (m, 1H), 2.47-2.38 (m, 1H), 2.34 (s, 3H),
2
.30 (s, 3H), 2.15-2.06 (m, 2H), 2.06-1.98 (m, 1H), 1.87 (s, 3H), 1.83-1.69 (m, 8H), 1.65-1.34
1
3
1
(
m, 7H). C{ H}-NMR (100 MHz, CDCl
3
): δ 178.4, 138.5, 137.1, 136.0, 134.5, 129.5, 128.0,
1
2
23.3, 117.2, 82.5, 82.5, 62.3, 51.4, 50.5, 37.4, 35.3, 34.8, 32.6, 29.7, 29.0, 27.9, 27.8, 25.4,
3
5
191
+.
+.
5.0, 21.2, 19.6, 17.9. HRMS (ASAP) calcd for C27
H
38 Cl IrN
2
([M] ): m/z 616.2330,
found: m/z 616.2333 (1 ppm).
[
(3-cyclooctyl-1-mesityl-imidazol-2-ylidene)-(cyclooctadi-
ene)-iridium chloride] 7d was prepared from [Ir-µCl-(cod)]
2
N
N
(
59 mg, 0.088 mmol), t-BuOK (20 mg, 0.176 mmol), 3-
cyclooctyl-1-mesityl-imidazolium tetrafluoroborate 1d-BF
4
(61
mg, 0.158 mmol) in THF (5 mL). 7d was obtained as a yellow
Cl
Ir
1
solid (87 mg, 87 %). H-NMR (400 MHz, CDCl
3
): δ 7.01 (d,
3
J
J
H-H = 2.0 Hz, 1H), 7.00 (br. s, 1H), 6.89 (br. s, 1H), 6.72 (d,
H-H = 2.0 Hz, 1H), 6.02-5.91 (m, 1H), 4.55-4.45 (m, 1H), 4.39-
.32 (m, 1H), 3.10-3.02 (m, 1H), 2.80-2.75 (m, 1H), 2.35 (s,
3
4
3
1
H), 2.31 (s, 3H), 2.17-2.05 (m, 2H), 2.00-1.91 (m, 2H), 1.88 (s, 3H), 1.91-1.64 (m, 12H),
1
3
1
.63-1.56 (m, 1H), 1.56-1.46 (m, 3H), 1.46-1.35 (m, 1H), 1.26-1.16 (m, 1H); C{ H}-NMR
): δ 178.3, 138.6, 137.1, 136.0, 134.5, 129.5, 128.1, 123.4, 117.3, 83.0,
2.3, 60.4, 51.0, 51.0, 36.8, 34.4, 34.3, 33.2, 29.4, 29.2, 27.1, 26.4, 26.0, 24.9, 24.9, 21.2,
(
100 MHz, CDCl
3
8
1
6
3
5
193
+
+
9.7, 17.9; HRMS (ASAP) calcd for C28
33.2579 (1 ppm).
H
41 Cl IrN
2
([M+H] ): m/z 633.2588, found: m/z
[
(3-cyclododecyl-1-mesityl-imidazol-2-ylidene)-(cyclo-
octadiene)-iridium chloride] 7e was prepared from [Ir-µCl-
cod)] (49 mg, 0.073 mmol), t-BuOK (18 mg, 0.158 mmol),
-cyclododecyl-1-mesityl-imidazolium tetrafluoroborate 1e-
N
N
(
3
2
4
BF (59 mg, 0.134 mmol) in THF (5 mL). 7e was obtained as
Cl
1
Ir
a yellow solid (92 mg, 99 %). H-NMR (400 MHz, CDCl
3
):
3
δ 7.05 (d, JH-H = 2.0 Hz, 1H), 7.02 (br. s, 1H), 6.90 (br. s,
3
1
4
H), 6.73 (d, JH-H = 2.0 Hz, 1H), 5.67-5.58 (m, 1H), 4.60-
.53 (m, 1H), 4.34-4.28 (m, 1H), 3.02-2.95 (m, 1H), 2.88-
2
1
.82 (m, 1H), 2.36 (s, 3H), 2.34 (s, 3H), 2.24-2.14 (m, 2H), 2.14-1.99 (m, 2H), 1.88 (s, 3H),
1
3
1
.87-1.76 (m, 2H), 1.75-1.62 (m, 2H), 1.54-1.50 (m, 2H), 1.50-1.24 (m, 18H); C{ H}-NMR
): δ 179.1, 138.6, 137.2, 136.3, 134.7, 129.6, 128.0, 123.3, 117.9, 83.9,
1.9, 57.9, 52.4, 50.0, 34.5, 32.3, 30.5, 30.4, 28.0, 23.5, 23.0, 22.8, 22.7, 22.4, 21.2, 19.8,
(
100 MHz, CDCl
3
8
1
3
5
193
+
+.
2
7.9; HRMS (ASAP) calcd for C32H48 Cl IrN ([M] ): m/z 688.3135, found: m/z 688.3124
(
2 ppm). Single-crystals of 7e were obtained by slow evaporation of a saturated solution in
diethyl ether. CCDC 927645.
ꢀ
9
ꢀ

ꢀ
2
.2.b. Rhodium complexes 8a-b
General procedure for the synthesis of [(3-cycloalkyl-1-mesityl-imidazol-2-ylidene)-
cyclooctadiene)-rhodium chloride] complexes 8a-b. In a flame-dried Schlenk tube were
placed [Rh-µCl-(cod)] (0.05 mmol, 1.0 equiv.), t-BuOK (0.10 mmol, 2.0 equiv.) and THF (3
(
2
mL) under argon atmosphere. The mixture was stirred at room temperature for 10 min then
imidazolium salt (0.10 mmol, 2.0 equiv.) was added and the resulting mixture was stirred for
2
h at room temperature. The mixture was filtered on celite bed and concentrated under
reduced pressure. The resulting crude product was washed with dichloromethane/ethyl
acetate/diethyl ether (3/1/1, 10 mL) to afford the desired product as a yellow solid.
[
-
0
(3-cyclopentyl-1-mesityl-imidazol-2-ylidene)-(cyclooctadiene)
rhodium chloride] 8a was prepared from [Rh-µCl-(cod)] (25 mg,
.05 mmol), t-BuOK (11 mg, 0.10 mmol), 3-cyclopentyl-1-mesityl-
2
N
N
4
imidazolium tetrafluoroborate 1a-BF (34 mg, 0.10 mmol) in THF
1
(
3 mL). 8a was obtained as a yellow solid (41 mg, 85 %). H-NMR
Cl
3
Rh
3
(400 MHz, CDCl ): δ 7.07 (br. s, 1H), 7.03 (d, JH-H = 1.8 Hz, 1H),
.90 (br. s, 1H), 6.75 (d, JH-H = 1.8 Hz, 1H), 6.32-6.22 (m, 1H),
.85-4.74 (m, 2H), 3.50-3.43 (m, 1H), 2.96-2.89 (m, 1H), 2.56-2.49
3
6
4
(
m, 1H), 2.41 (s, 3H), 2.36 (s, 3H), 2.16-2.05 (m, 1H), 2.05-1.70
1
3
1
(
m, 10H) 1.82 (s, 3H), 1.68-1.57 (m, 1H), 1.54-1.37 (m, 2H); C{ H}-NMR (100 MHz, CDCl
3
):
δ 182.2 (d, JC-Rh = 51 Hz), 138.6, 137.3, 136.3, 134.4, 129.6, 128.2, 123.7, 123.7, 117.2,
7.3 (d, JC-Rh = 7.0 Hz), 96.4 (d, JC-Rh = 7.4 Hz), 68.5 (d, JC-Rh = 14.4 Hz), 66.7 (d, JC-Rh = 14.6
Hz), 62.5, 35.3, 34.7, 33.3, 31.3, 29.7, 27.7, 25.1, 24.8, 21.2, 19.9, 17.9; HRMS (ASAP)
1
9
3
5
+.
+.
2
calcd for C25H34 ClN Rh ([M] ): m/z 500.1466, found: m/z 500.1469 (1 ppm). Single-
crystals of 8a were obtained by slow evaporation of a saturated solution in diethyl ether.
CCDC 935381.
[
(3-cyclododecyl-1-mesityl-imidazol-2-ylidene)-(cyclo-
octadiene)-rhodium chloride] 8b was prepared from [Rh-
N
N
µCl-(cod)]
2
(25 mg, 0.05 mmol), t-BuOK (11 mg, 0.10
mmol),
3-cyclododecyl-1-mesityl-imidazolium
tetrafluoroborate 1e-BF
8b was obtained as a yellow solid (44 mg, 73 %). H-NMR
4
(44 mg, 0.10 mmol) in THF (3 mL).
1
Cl
Rh
3
(
1
(
400 MHz, CDCl
H), 6.91 (br. s, 1H), 6.74 (d, JH-H = 2.0 Hz, 1H), 5.92-5.83
m, 1H), 5.00-4.92 (m, 1H), 4.76-4.68 (m, 1H), 3.41-3.33 (m,
H), 3.15-3.08 (m, 1H), 2.45 (s, 3H), 2.37 (s, 3H), 2.35-2.10 (m, 4H), 1.93-1.78 (m, 4H), 1.80
3
): δ 7.08 (br. s, 1H), 7.03 (d, JH-H = 2.0 Hz,
3
1
(
1
3
1
s, 3H), 1.78-1.66 (m, 4H), 1.66-1.52 (m, 6H), 1.52-1.34 (m, 12H); C{ H}-NMR (100 MHz,
1
CDCl
7.3 (d, JC-Rh = 7.2 Hz), 96.3 (d, JC-Rh = 7.2 Hz), 68.8 (d, JC-Rh = 14.4 Hz), 66.7 (d, JC-Rh = 14.4
Hz), 58.6, 33.1, 32.9, 31.8, 30.4, 29.3, 26.7, 24.6, 24.5, 24.0, 23.9, 22.9, 22.7, 22.4, 22.3,
3
): δ 181.2 (d, JC-Rh = 51.3 Hz), 138.6, 137.5, 136.6, 134.7, 129.7, 128.1, 123.3, 118.2,
9
+
.
+.
2
5
1.2, 20.0, 17.8; HRMS (ASAP) calcd for C32
2
H48ClN Rh ([M] ): m/z 598.2561, found: m/z
98.2570 (2 ppm). Single-crystals of 8b were obtained by slow evaporation of a saturated
solution in ethyl acetate/dichloromethane (10/1). CCDC 936702.
2
.2.c. Silver complexes 9a-d
ꢀ
General procedure for the synthesis of [(3-cycloalkyl-1-mesityl-imidazol-2-ylidene)-
silver chloride] complexes 9a-d. In a dry round-bottomed flask under argon atmosphere
were placed Ag O (0.05 mmol, 0.5 equiv.), imidazolium chloride salt (0.10 mmol, 1.0 equiv.),
2
dichloromethane (2.5 mL) and 4Å molecular sieves. The resulting mixture was stirred at
room temperature for 14 h in darkness (aluminum foil). The solution was then filtered on a
1
0
ꢀ

celite bed and dichloromethane was removed under reduced pressure. The resulting solid
was washed with diethyl ether to afford the desired product as a white solid.
[
9
(3-cyclopentyl-1-mesityl-imidazol-2-ylidene)-silver chloride]
was prepared from 3-cyclopentyl-1-mesityl-imidazolium
chloride 1a-Cl (29 mg, 0.10 mmol), Ag O (12 mg, 0.05 mmol) and
CH Cl (2.5 mL). 9a was obtained as a white solid (31 mg, 78 %
yield). H-NMR (400 MHz, CDCl
a
N
N
2
2
2
1
Ag
Cl
3
): δ 7.21-7.17 (m, 1H), 6.95-6.91
m, 3H), 4.95 (qi, JH-H = 6.4 Hz, 1H), 2.35-2.26 (m, 2H), 2.32 (s,
3
(
1
3
1
3
H), 1.99-1.81 (m, 6H), 1.95 (s, 6H), 1.81-1.72 (m, 2H); C{ H}-NMR (100 MHz, CDCl
3
): δ
1
40.7, 137.6, 134.0, 130.7, 129.5, 123.6, 120.9, 61.3, 33.6, 23.8, 20.8, 17.4; Elem. anal.
calcd. for C17
H
2
22AgClN : C, 51.34; H, 5.58; N, 7.04. Found: C, 51.40; H, 5.67; N, 7.03.
[
(3-cyclododecyl-1-mesityl-imidazol-2-ylidene)-silver
chloride] 9b was prepared from 3-cyclododecyl-1-mesityl-
imidazolium chloride 1e-Cl (39 mg, 0.10 mmol), Ag O (12
mg, 0.05 mmol) and CH Cl (2.5 mL). 9b was obtained as a
white solid (43 mg, 86 % yield). H-NMR (400 MHz, CDCl
N
N
2
2
2
1
3
):
Ag
Cl
3
δ 7.17-7.14 (m, 1H), 6.95-6.92 (m, 2H), 4.67 (qi, JH-H = 6.4
Hz, 1H), 2.32 (s, 3H), 2.15-2.04 (m, 2H), 1.96 (s, 6H), 1.78-
1
3
1
1
.68 (m, 2H), 1.60-1.51 (m, 2H), 1.51-1.32 (m, 16H); C{ H}-NMR (100 MHz, CDCl
3
):
δ 139.1, 135.3, 134.5, 129.1, 122.4, 118.5, 58.4, 31.4, 23.5, 23.3, 23.1, 23.0, 21.5, 20.8,
1
07
+
+
1
(
7.4; HRMS (ASAP) calcd for C24
1 ppm). Single-crystals of 9b were obtained by slow evaporation in darkness (alumina foil)
of a saturated solution in ethyl acetate. CCDC 930139.
2
H36 AgN ([M − Cl] ): m/z 459.1929, found: m/z 459.1926
[
(3-cyclododecyl-1-diisopropylphenyl-imidazol-2-ylidene)-
silver chloride] 9c was prepared from 3-cyclododecyl-1-
diisopropylphenyl-imidazolium chloride 1i-Cl (100 mg, 0.230
N
N
mmol), Ag
2 2 2
O (27 mg, 0.115 mmol) and CH Cl (10 mL). 9c was
1
obtained as a white solid (100 mg, 80 % yield). H-NMR (400
MHz, CDCl ): δ 7.43 (t, JH-H = 7.6 Hz, 1H), 7.24 (s, 2H), 7.22
3
3
Ag
Cl
3
3
(
s, 1H), 7.18 (t, JH-H =1.6 Hz, 1H), 6.98 (t, JH-H = 1.6 Hz, 1H),
3
3
4
.70 (qi, JH-H = 6.4 Hz, 1H), 2.32 (sep, JH-H = 6.8 Hz, 2H),
2
J
.15-2.07 (m, 2H), 1.79-1.71 (m, 2H), 1.59-1.55 (m, 2H), 1.48-1.37 (m, 16H), 1.21 (d,
3
3
13
H-H = 6.8 Hz, 6H), 1.11 (d, JH-H = 6.8 Hz, 6H). C-NMR (100 MHz, CDCl
3
): δ 145.6, 134.9,
1
2
5
30.3, 124.2, 124.1, 123.9, 123.8, 118.5, 118.4, 58.6, 31.6, 28.2, 24.5, 24.2, 23.7, 23.5, 23.2,
1
07
+.
+.
3.1, 21.6. HRMS (ASAP) calcd for C27
01.2384 (3 ppm).
H
42 AgN
2
([M − Cl] ): m/z 501.2399, found: m/z
[
(3-(1R,2S,3S,5R)-isopinocampheyl-1-mesityl-imidazol-2-
ylidene)-silver chloride] 9d was prepared from 3-
1R,2S,3S,5R)-isopinocampheyl-1-mesitylimidazolium chloride
k-Cl (150 mg, 0.42 mmol), Ag O (50 mg, 0.21 mmol) and
CH Cl (10 mL). 9d was obtained as a white solid (178 mg, 91
3
yield). H-NMR (400 MHz, CDCl ): δ 7.31 (s, 1H), 6.99 (d,
N
N
(
1
2
Ag
Cl
2
2
1
%
3
3
3
J
H-H = 1.6 Hz, 1H), 6.93 (s, 2H), 4.95 (dt, JH-H = 10.0 Hz, JH-H = 7.6 Hz, 1H), 2.75-2.68 (m,
1
7
H), 2.64-2.58 (m, 1H), 2.31 (s, 3H), 2.33-2.26 (m, 1H), 2.14-2.04 (m, 2H), 1.97-1.95 (m,
3
3
H), 1.29 (s, 3H), 1.19 (d, JH-H = 10.2 Hz, 1H), 1.17 (d, JH-H = 7.5 Hz, 3H), 1.10 (s, 3H);
1
3
1
1
C{ H}-NMR (100 MHz, CDCl
29.6,129.5, 123.7-123.6 (m), 118.4-118.3 (m), 62.4, 47.6, 45.8, 41.7, 39.3, 37.1, 35.5, 28.1,
3.8, 21.2, 20.3, 17.8, 17.7; Elem. Anal. Calcd. for C22 : C, 56.73; H, 6.49; N, 6.01.
)).
3
): δ 181.1 (d, JC-Ag = 256 Hz), 139.6, 135.5, 134.9, 134.8,
1
2
H30AgClN
2
2
0
Found: C, 56.51; H, 6.66; N, 5.99. [α]
D 3
= + 2.0 (c = 0.96 (CHCl
1
1
ꢀ

2
.2.d. Copper complexes 10a-b
General procedure for the synthesis of [(3-cycloalkyl-1-mesityl-imidazol-2-ylidene)-
copper chloride] complexes 10a-b. In a dry round-bottomed flask were placed [(3-
cycloalkyl-1-mesityl-imidazol-2-ylidene)-silver chloride] (0.11 mmol, 1.0 equiv.), CuCl (0.11
mmol, 1.1 equiv.) and CH
room temperature for 20 h then filtered on a celite bed with CH
2
Cl
2
(10 mL) under argon atmosphere. The mixture was stirred at
Cl and the solvent was
2
2
removed under reduced pressure. The crude solid was washed with pentane to afford the
desired copper complex.
[
(3-cyclododecyl-1-mesityl-imidazol-2-ylidene)-copper
chloride] 10a was prepared from [(3-cyclododecyl-1-
mesityl-imidazol-2-ylidene)-silver chloride] 9b (50 mg, 0.10
N
N
mmol), CuCl (11 mg, 0.11 mmol) and CH
was obtained as a white solid (44 mg, 99 %). H-NMR (400
MHz, CDCl ): δ 7.09 (s, 1H), 6.93 (s, 2H), 6.85 (s, 1H), 4.74
qi, JH-H = 6.6 Hz, 1H), 2.31 (s, 3H), 2.18-2.05 (m, 2H), 1.98
2 2
Cl (10 mL). 10a
1
Cu
Cl
3
3
(
1
3
1
(
s, 6H), 1.79-1.68 (m, 2H), 1.65-1.54 (m, 2H), 1.49-1.30 (m, 17H); C{ H}-NMR (100 MHz,
CDCl ): δ 176.9, 139.3, 134.8, 129.4, 122.1, 118.3, 58.2, 32.0, 23.9, 23.7, 23.3, 23.2, 21.9,
3
6
3
+.
+.
2
4
1.2, 17.8; HRMS (ASAP) calcd for C24
H
35 CuN
2
([M − HCl] ): m/z 414.2096, found: m/z
14.2104 (2 ppm). Single-crystals of 10a were obtained by slow evaporation of a saturated
solution in acetone. CCDC 921286.
[
(3-(1R,2S,3S,5R)-isopinocampheyl-1-mesityl-imidazol-2-
ylidene)-copper chloride] 10b was prepared from [(3-
N
N
(
1R,2S,3S,5R)-isopinocampheyl-1-mesityl-imidazol-2-ylidene)-
silver chloride] 9d (50 mg, 0.10 mmol), CuCl (11 mg, 0.11
mmol) and CH Cl (10 mL). 10b was obtained as a pale white
solid (45 mg, 99 % yield). H-NMR (400 MHz, CDCl
Cu
Cl
2
2
1
3
): δ 7.24
(
(
br. s, 1H), 6.94 (br. s, 2H), 6.91 (br. s, 1H), 5.12-5.00 (m, 1H), 2.78-2.71 (m, 1H), 2.63-2.57
m, 1H), 2.31 (s, 3H), 2.34-2.27 (m, 1H), 2.15-2.06 (m, 2H), 2.04-1.96 (m, 1H), 2.00 (s, 3H),
3
3
1
3
1
1
3
.99 (s, 3H), 1.30 (s, 3H), 1.24 (d, JH-H = 10.3 Hz, 1H), 1.19 (d, JH-H = 7.1 Hz, 3H), 1.13 (s,
1
3
1
H); C{ H}-NMR (100 MHz, CDCl
3
): δ 177.6, 139.4, 135.4, 134.8, 134.8, 129.5, 129.5,
23.1, 123.1, 123.1, 118.1, 61.8, 47.7, 45.9, 41.7, 39.3, 37.2, 35.5, 28.2, 23.7, 21.2, 20.3,
6
3
+.
+.
7.9, 17.8; HRMS (ASAP) calcd for C22
84.1632 (1 ppm); [α]
H
29 CuN
2
([M − HCl] ): m/z 384.1627, found: m/z
2
0
D
= - 2.3 (c = 0.99 (acetone)).
2
.2.e. Gold complexes 11a-b
General procedure for the synthesis of [(3-cycloalkyl-1-mesityl-imidazol-2-ylidene)-
gold chloride] complexes 11a-b. In a dry Schlenk were placed [(3-cycloalkyl-1-mesityl-
imidazol-2-ylidene)-silver chloride] (0.056 mmol, 1.0 equiv.), Me
2
S.AuCl (0.056 mmol, 1.0
equiv.) and CH Cl (7 mL) under argon atmosphere. The mixture was stirred at room
2
2
temperature for 3 h then filtered on celite bed and the solvent was removed under reduced
pressure. The crude solid was washed with diethyl ether to afford the desired gold complex.
[
(3-cyclododecyl-1-mesityl-imidazol-2-ylidene)-gold
chloride] 11a was prepared from [(3-cyclododecyl-1-
mesityl-imidazol-2-ylidene)-silver chloride] 9b (28 mg, 0.056
N
N
mmol), Me
2 2 2
S.AuCl (16 mg, 0.056 mmol) and CH Cl (7 mL).
1
Au
Cl
11a was obtained as a white solid (33 mg, 99 %). H-NMR
3
(
(
3
400 MHz, CDCl ): δ 7.15 (d, JH-H = 2.0 Hz, 1H), 6.94-6.92
m, 2H), 6.86 (d, JH-H = 2.0 Hz, 1H), 5.04 (qi, JH-H = 6.4 Hz,
3
3
1
H), 2.31 (s, 3H), 2.16-2.04 (m, 2H), 1.99 (s, 6H), 1.77-1.62 (m, 4H), 1.56-1.31 (m, 17H);
1
2
ꢀ

1
3
1
C{ H}-NMR (100 MHz, CDCl
3
): δ 171.5, 139.6, 135.0, 134.9, 129.4, 122.3, 117.8, 58.0,
: C, 49.28;
3
1.4, 23.9, 23.6, 23.5, 23.3, 21.8, 21.2, 17.8. Elem. Anal. Calcd. for C24H36AuClN
2
H, 6.20; N, 4.79. Found: C, 49.35; H, 6.33; N, 4.75. Single-crystals of 11a were obtained by
slow evaporation of a saturated solution in ethyl acetate. CCDC 933273.
[
(3-(1R,2S,3S,5R)-isopinocampheyl-1-mesityl-imidazol-2-
ylidene)-gold chloride] 11b was prepared from [(3-
1R,2S,3S,5R)-isopinocampheyl-1-mesityl-imidazol-2-ylidene)-
silver chloride] 9d (50 mg, 0.107 mmol), Me S.AuCl (32 mg,
.108 mmol) and CH Cl (14 mL). 11b was obtained as a
white solid (53 mg, 89 %). H-NMR (400 MHz, CDCl
N
N
(
2
Au
Cl
0
2
2
1
3
): δ 7.30
3
3
3
3
(
d, JH-H = 2.0 Hz, 1H), 6.94 (s, 2H), 6.92 (d, JH-H = 2.0 Hz, 1H), 5.38 (dt, JH-H = 10.5 Hz, JH-H
=
2
7.6 Hz, 1H), 2.80-2.73 (m, 1H), 2.64-2.58 (m, 1H), 2.35-2.27 (m, 1H), 2.32 (s, 3H), 2.14-
3
.10 (m, 1H), 2.07-1.95 (m, 2H), 2.01 (s, 3H), 2.00 (s, 3H), 1.30 (s, 3H), 1.23 (d, JH-H = 7.2
3
13
1
Hz, 3H), 1.18 (d, JH-H = 10.3 Hz, 1H), 1.13 (s, 3H); C{ H}-NMR (100 MHz, CDCl
3
): δ 172.1,
1
3
−
39.7, 135.0, 135.0, 134.9, 134.7, 129.5, 129.5, 123.2, 117.8, 61.3, 47.7, 45.6, 41.7, 39.3,
+
.
6.8, 35.5, 28.1, 23.8, 21.2, 20.2, 17.9, 17.8; HRMS (ASAP) calcd for C22
H
29AuN
2
([M
+
.
20
HCl] ): m/z 518.1996, found: m/z 518.2012 (3 ppm); [α]
D
= - 2.3 (c = 0.98 (acetone)).
Single-crystals of 11b were obtained by slow evaporation of a saturated solution in ethyl
acetate. CCDC 939289.
2
.2.f. Palladium complexes 12a-c
General procedure for the synthesis of [(3-cycloalkyl-1-mesityl-imidazol-2-ylidene)-
palladium chloride] complexes 12a-c. In a dry round-bottomed flask under argon
atmosphere were placed [(3-cycloalkyl-1-aryl-imidazol-2-ylidene)-silver chloride] (0.20 mmol,
1
2 2 2
.0 equiv.), [Pd(π-allyl)Cl] (0.10 mmol, 0.5 equiv.) and anhydrous CH Cl (10 mL). The
mixture was stirred at room temperature overnight then filtered on celite bed and the volatiles
were removed under reduced pressure. The white solid was washed with pentane to afford
the desired palladium complex.
[
(3-cyclododecyl-1-mesityl-imidazol-2-ylidene)-(allyl)-
palladium chloride] 12a was prepared from [(3-
cyclododecyl-1-mesityl-imidazol-2-ylidene)-silver chloride]
b (100 mg, 0.20 mmol), [Pd(π-allyl)Cl] (36 mg, 0.10 mmol)
and CH Cl (10 mL). 12a was obtained as a white solid (105
mg, 99% yield). H-NMR (400 MHz, CDCl
N
N
9
2
2
2
Pd Cl
1
3
3
): δ 7.12 (d, JH-H
2.0 Hz, 1H), 6.93 (br s, 1H), 6.90 (d, JH-H = 2.0 Hz, 1H)
3
=
2
3
6
1
.89 (br s, 1H), 5.23-5.17 (m, 1H), 5.00-4.91 (m, 1H), 4.08 (dd, JH-H = 1.6 Hz, JH-H = 5.6 Hz,
H), 3.10 (d, JH-H = 6.8 Hz, 1H), 2.96 (d, JH-H = 13.2 Hz, 1H), 2.30 (s, 3H), 2.18 (s, 3H), 2.01
3
3
1
3
1
(
s, 3H), 1.99-1.91 (m, 1H), 1.90-1.79 (m, 1H), 1.70-1.64 (m, 4H), 1.37 (br, 16H); C{ H}-
NMR (100 MHz, CDCl ): δ 181.0, 138.6, 136.3, 136.0, 135.3, 129.0, 128.5, 122.4, 118.0,
14.3, 72.5, 56.8, 48.1, 31.5, 30.8, 29.7, 24.3, 24.2, 23.5, 23.4, 23.0, 22.9, 22.8, 22.1, 21.0,
8.4, 17.9; Elem. Anal. Calcd. for C27 Pd: C, 60.56; H, 7.72; N, 5.23. Found: C, 60.47;
3
1
1
H
41ClN
2
H, 7.84; N, 5.18. Single-crystals of 12a were obtained by slow evaporation of a saturated
solution in diethyl ether. CCDC 929979.ꢀ
[
(3-cyclododecyl-1-diisopropylphenyl-imidazol-2-ylidene)-
(
allyl)palladium chloride] 12b was prepared from [(3-
cyclododecyl-1-diisopropylphenyl-imidazoline-2-ylidene)-silver
N
N
chloride] 9c (127 mg, 0.24 mmol), [Pd(π-allyl)Cl]
mmol) and CH Cl (10 mL). 12b was obtained as a white solid
110 mg, 78% yield) (partial degradation of 12b was observed
2
(43 mg, 0.12
2
2
(
1
3
Pd Cl
3
after few hours). RMN- H (400 MHz, CDCl ): δ 7.39 (t, JH-H =
1
3
ꢀ

3
4
3
4
7
.6 Hz, 1H), 7.26 (dd, JH-H = 6.4 Hz, JH-H = 1.2 Hz, 1H), 7.20 (dd, JH-H = 6.4 Hz, JH-H = 1.2
3
3
Hz, 1H), 7.11 (d, JH-H = 2.0 Hz, 1H), 6.97 (d, JH-H = 2.0 Hz, 1H), 5.32-5.26 (m, 1H), 4.97-
.91 (m, 1H), 4.09 (dd, JH-H = 2.0 Hz, JH-H = 5.6 Hz, 1H), 3.00-2.93 (m, 1H), 2.99 (d, JH-H =
.80 Hz, 1H), 2,95 (d, JH-H = 13.6 Hz, 1H), 2.54 (sep., JH-H = 6.8 Hz, 1H), 2.01-1.97 (m,
H), 1.75-1.70 (m, 1H), 1.68-1.63 (m, 1H), 1.65 (d, JH-H = 12.0 Hz, 1H) 1.50-1.37 (m, 16H),
,34 (d, JH-H = 6.4 Hz, 3H), 1.26 (d, JH-H = 6.8 Hz, 3H), 1.06 (d, JH-H = 6.8 Hz, 3H), 1.04 (d,
H-H = 6.8 Hz, 3H). C-NMR (100 MHz, CDCl
2
3
3
4
6
4
3
3
3
3
3
3
1
3
13
J
3
): δ 182.2, 147.0, 146.1, 136.2, 129.8, 129.1,
1
2
5
28.3, 124.2, 123.9, 123.4, 117.7, 114.3, 72.9, 57.4, 48.3, 31.3, 30.7, 28.3, 26.5, 26.2, 24.2,
1
06
+.
+.
3.6, 23.5, 23.4, 23.3, 22.9, 22.1, 21.9. HRMS for C30
H
47
N
2
Pd ([M − HCl] ): calcd
41.2774, found 541.2788 (3 ppm). Single-crystals of 12b were obtained by slow
evaporation of a saturated solution in diethyl ether. CCDC 938918.
[
(3-(1R,2S,3S,5R)-isopinocampheyl-1-mesityl-imidazoline-
2
-ylidene)-(allyl)palladium chloride] 12c was prepared from
[
N
N
(3-(1R,2S,3S,5R)-isopinocampheyl-1-mesityl-imidazoline-2-
ylidene)-silver chloride] 9d (143 mg, 0.31 mmol), [Pd(π-
allyl)Cl] (58 mg, 0.16 mmol) and anhydrous CH Cl (15 mL)
under argon atmosphere. 12c was obtained as a white solid
mixture of isomers I1/I2 (ratio 1.0/0.6), 133 mg, 85 % yield).
2
2
2
Pd Cl
(
1
H-NMR (400 MHz, CDCl
.97 (m, 3H, I1+I2), 5.76-5.47 (m, 1H, I1+I2), 5.12-4.73 (m, 1H, I1+I2), 4.11-4.04 (m, 1H,
I1+I2), 3.13-2.92 (m, 3H, I1+I2), 2.58-2.54 (m, 1H, I1+I2), 2.30-2.29 (m, 5H, I1+I2), 2.18-1.89
3
): δ 7.28-7.23 (m, 1H, I1+I2), 6.96-
6
3
(
m, 9H, I1+I2), 1.56 (d, JH-H = 7.6 Hz, 0.6H, I2), 1.28-1.26 (m, 3H, I1/I2), 1.17-1.05 (m, 7H,
1
3
I1/I2). C-NMR (100 MHz, CDCl
3
): δ 181.8, 181.4, 138.8, 138.7, 136.9, 136.5, 136.4, 136.3,
34.7, 129.4, 129.2, 128.6, 128.4, 123.5, 123.3, 118.1, 118.0, 114.5, 114.3, 72.9, 72.1, 60.6,
0.2, 48.8, 48.4, 45.9, 45.5, 41.9, 41.9, 39.3, 39.3, 37.4, 37.0, 35.8, 35.6, 28.3, 28.3, 23.7,
3.7, 21.2, 20.5, 20.0, 18.9, 18.7, 18.1, 17.8. Elem. Anal. Calcd. for C25 Pd: C, 59.41;
= + 28.9 (c = 1.0 (CHCl )).ꢀ
1
6
2
H35ClN
2
2
0
H, 6.98; N, 5.54. Found: C, 59.01; H, 7.09; N, 5.60; [a]
D
3
2
.2.g. Iridium CO complexes 13a-e
General procedure for the synthesis of the [(3-cycloalkyl-1-mesityl-imidazol-2-ylidene)-
bis-(carbon monoxide))-iridium chloride] complexes 13a-e. In a dry round-bottomed
(
flask were placed [(NHC)IrCl(cod)] complexe and dichloromethane. CO gaz was bubbled into
the solution for 15 min then volatiles were removed under reduced pressure. The resulting
crude solid mixture was washed with pentane to afford the desired product as a yellow solid.
[
(3-cyclopentyl-1-mesityl-imidazol-2-ylidene)-(bis-(carbon
monoxide))-iridium chloride] 13a was prepared from [(3-
cyclopentyl-1-mesityl-imidazol-2-ylidene)-(cyclooctadiene)-iridium
chloride] 7a (18 mg, 0.029 mmol) in dichloromethane (5 mL). 13a
N
N
1
was obtained as a yellow solid (13 mg, 81 %). H-NMR (400 MHz,
Ir CO
CO
3
Cl
CDCl
J
3
): δ 7.21 (d, JH-H = 2.0 Hz, 1H), 6.98-6.97 (m, 2H), 6.92 (dd,
3
4
3
H-H = 2.0 Hz, JH-H = 0.4 Hz, 1H), 5.53 (qi, JH-H = 8.1 Hz, 1H),
1
3
1
2
.47-2.36 (m, 2H), 2.36 (s, 3H), 2.07 (s, 6H), 1.95-1.73 (m, 6H); C{ H}-NMR (100 MHz,
CDCl ): δ 181.0, 174.7, 168.1, 139.6, 135.3, 129.3, 123.6, 118.3, 62.3, 34.1, 24.6, 21.3, 18.4,
NHC not observed. IR (KBr, solution in CH
3
-
1
C
(
2
+
Cl
2
, cm ): 2065.4 (CO), 1981.3 (CO). HRMS
3
5
193
+
ASAP) calcd for C19H23 Cl IrN O ([M+H] ): m/z 539.1078, found: m/z 539.1069 (2 ppm).
2 2
1
4
ꢀ

[
(3-cyclohexyl-1-mesityl-imidazol-2-ylidene)-(bis-(carbon
monoxide))-iridium chloride] 13b was prepared from [(3-
cyclohexyl-1-mesityl-imidazol-2-ylidene)-(cyclooctadiene)-iridium
chloride] 7b (23 mg, 0.036 mmol) in dichloromethane (5 mL). 13b
N
N
1
was obtained as a yellow solid (20 mg, 99 %). H-NMR (400
Ir CO
CO
Cl
3
MHz, CDCl
J
3
): δ 7.20 (d, JH-H = 2.0 Hz, 1H), 6.97 (s, 2H), 6.90 (d,
3
H-H = 2.0 Hz, 1H), 5.09-5.00 (m, 1H), 2.35 (s, 3H), 2.33-2.23 (m,
2
1
H), 2.07 (s, 6H), 1.94-1.86 (m, 2H), 1.83-1.75 (m, 1H), 1.64-1.47 (m, 4H), 1.30-1.18 (m,
1
3
1
H); C{ H}-NMR (100 MHz, CDCl
3
): δ 181.1, 174.2, 168.1, 139.6, 135.3, 129.3, 123.3,
1
18.4, 60.5, 34.2 (br. s), 25.5, 25.4, 18.3 (br. s), CNHC not observed. IR (KBr, solution in
-
1
2 2 2 2
CH Cl , cm ): 2065.3 (CO), 1981.0 (CO); Elem. Anal. Calcd. for C20H26ClIrN O : C, 43.35; H,
4
.73; N, 5.06. Found: C, 43.54; H, 4.57; N, 5.10.ꢀ
[
(3-cycloheptyl-1-mesityl-imidazol-2-ylidene)-(bis-(carbon
monoxide))-iridium chloride] 13c was prepared from [(3-
cycloheptyl-1-mesityl-imidazol-2-ylidene)-(cyclooctadiene)-
iridium chloride] 7c (24 mg, 0.037 mmol) in dichloromethane (5
N
N
1
Ir CO
CO
mL). 13c was obtained as a yellow solid (20 mg, 95 %). H-NMR
Cl
3
(
6
400 MHz, CDCl
3
): δ 7.20 (d, JH-H = 2.0 Hz, 1H), 6.97 (s, 2H),
3
.90 (d, JH-H = 2.0 Hz, 1H), 5.30-5.22 (m, 1H), 2.35 (s, 3H),
1
3
1
2
3
.31-2.21 (m, 2H), 2.06 (s, 6H), 1.88-1.57 (m, 11H); C{ H}-NMR (100 MHz, CDCl ):
δ 181.1, 173.6, 168.1, 139.6, 135.3, 129.3, 123.5, 118.4, 62.6, 36.1 (br.s), 29.8, 27.8, 24.7,
-
1
2
1.3, 18.4 (br. s.), CNHC not observed. IR (KBr, solution in CH
2
Cl
2
, cm ): 2065.1 (CO), 1980.8
([M+H] ): m/z 565.1367, found: m/z
65.1373 (1 ppm). Single-crystals of 13c were obtained by slow evaporation of a saturated
3
5
191
+
+
(
2 2
CO). HRMS (ASAP) calcd for C21H27 Cl IrN O
5
solution in diethyl ether. CCDC 933067.
[
(3-cyclooctyl-1-mesityl-imidazol-2-ylidene)-(bis-(carbon
monoxide))-iridium chloride] 13d was prepared from [(3-
cyclooctyl-1-mesityl-imidazol-2-ylidene)-(cyclooctadiene)-iridium
N
N
chloride] 7d (21 mg, 0.032 mmol) in dichloromethane (5 mL).
1
1
3d was obtained as a yellow solid (16 mg, 89 %). H-NMR
Ir CO
CO
Cl
3
(
400 MHz, CDCl
3
): δ 7.18 (d, JH-H = 2.0 Hz, 1H), 6.70 (s, 2H),
.90 (d, JH-H = 2.0 Hz, 1H), 5.50-5.41 (m, 1H), 2.35 (s, 3H),
.17-2.01 (m, 2H), 2.07 (s, 6H), 1.99-1.88 (m, 2H), 1.83-1.57 (m, 10H); C{ H}-NMR (100
3
6
1
3
1
2
MHz, CDCl
3
): δ 181.2, 173.7, 168.2, 139.5, 129.3, 123.5, 118.6, 61.0, 34.7 (br. s), 26.6, 26.4,
-
1
2
1
4.6, 21.3, 18.4 (br. s), CNHC not observed. IR (KBr, solution in CH
980.7 (CO); HRMS (ASAP) calcd for C22H29 Cl IrN O
2 2
2
+
Cl
2
, cm ): 2064.9 (CO),
3
5
193
+
([M+H] ): m/z 581.1547, found:
m/z 581.1542 (1 ppm). Single-crystals of 13d were obtained by slow evaporation of a
saturated solution in diethyl ether. CCDC 959340.
[
(3-cyclododecyl-1-mesityl-imidazol-2-ylidene)-(bis-
carbon monoxide))-iridium chloride] 13e was prepared
from [(3-cyclododecyl-1-mesityl-imidazol-2-ylidene)-
cyclooctadiene)-iridium chloride] 7e (25 mg, 0.037 mmol) in
(
N
N
(
dichloromethane (5 mL). 13e was obtained as a yellow solid
Ir CO
CO
Cl
1
3
(
1
21 mg, 99 %). H-NMR (400 MHz, CDCl
.8 Hz, 1H), 6.97 (br. s, 2H), 6.92 (d, JH-H = 1.8 Hz, 1H),
3
): δ 7.18 (d, JH-H
=
3
3
5
(
1
2
6
.37 (qi, JH-H = 6.8 Hz, 1H), 2.35 (s, 3H), 2.16-1.90 (m, 8H), 1.90-1.62 (m, 4H), 1.50-1.30
1
3
1
16H); C{ H}-NMR (100 MHz, CDCl
18.5, 57.2, 23.0, 22.6, 22.3, 21.3, CNHC not observed. IR (KBr, solution in CH Cl , cm ):
2 2
065.0 (CO), 1980.5 (CO); HRMS (ASAP) calcd for C26
35.2150, found: m/z 635.2152 (0 ppm).
3
): δ 181.1, 174.8, 168.4, 139.5, 135.2, 129.3, 123.6,
-
1
3
5
191
+
+
H
37 Cl IrN
2
O
2
([M+H] ): m/z
1
5
ꢀ

3
. NMR spectra
.1. NMR spectra of selectivities for the synthesis of imidazolium salts
3
1
H-NMR of crude 1a-OAc (selectivity)
OAc
OAc
OAc
N
N
N
N
N
N
bisC5&OAc(
1
a&OAc(
bisMes&OAc(
1
a&OAc(
Ra%o)
1a&OAc/bisC5&OAc/bisMes&OAc(=)93/3/4)
(
bisMes&OAc(
bisC5&OAc(
ꢀ
1
H-NMR of crude 1b-OAc (selectivity)
OAc
OAc
OAc
N
N
N
N
N
N
bisC6&OAc(
1
b&OAc(
bisMes&OAc(
1
b&OAc( Ra%o)
1b&OAc/bisC6&OAc/bisMes&OAc(=)90/8/2)
(
bisMes&OAc(
bisC6&OAc(
ꢀ
ꢀ
1
6

1
H-NMR of crude 1c-OAc (selectivity)
OAc
OAc
OAc
N
N
N
N
N
N
bisC7&OAc(
1
c&OAc(
bisMes&OAc(
Ra%o)
1c&OAc/bisC7&OAc/bisMes&OAc(=)93/5/3)
(
1
c&OAc(
bisMes&OAc(
bisC7&OAc(
ꢀ
1
H-NMR of crude 1d-OAc (selectivity)
OAc
OAc
OAc
N
N
N
N
N
N
1
d&OAc(
bisC8&OAc(
bisMes&OAc(
1
d&OAc(
Ra%o)
1d&OAc/bisC8&OAc/bisMes&OAc(=)93/5/3)
(
bisC8&OAc(
bisMes&OAc(
ꢀ
ꢀ
1
7
ꢀ

1
H-NMR of crude 1e-OAc (selectivity)
OAc
OAc
OAc
N
N
N
N
N
N
1
e&OAc(
bisC12&OAc(
bisMes&OAc(
1
e&OAc(
Ra%o)
1e&OAc/bisC12&OAc/bisMes&OAc(=)93/5/3)
(
bisC12&OAc(
bisMes&OAc(
1
H-NMR of crude 1f-OAc (selectivity)
OAc
OAc
OAc
N
N
N
N
N
N
1
f&OAc(
bisAdamantyl&OAc(
bisMes&OAc(
1
f&OAc(
Ra%o)
1f&OAc/bisAdamantyl&OAc/bisMes&OAc(=)88/4/8)
(
bisMes&OAc(
bis&(
Adamantyl&OAc(
1
8
ꢀ

1
H-NMR of crude 1h-OAc (selectivity)
OAc
OAc
OAc
N
N
N
N
N
N
1
h&OAc(
bisC5&OAc(
bisDipp&OAc(
Ra%o)
1
h&OAc(
(1h&OAc/bisC5&OAc/bisDipp&OAc(=)62/38/0)
bisC5&OAc(
1
H-NMR of crude 1i-OAc (selectivity)
OAc
OAc
OAc
N
N
N
N
N
N
bisC12&OAc(
1
i&OAc(
bisDipp&OAc(
Ra%o)
(1i&OAc/bisC12&OAc/bisDipp&OAc(=)57/43/0)
bisC12&OAc(
1
i&OAc(
1
9
ꢀ

1
H-NMR of crude 1j-OAc (selectivity)
OAc
OAc
OAc
N
N
N
N
N
N
HO
HO
OH
1
j&OAc(
bisC12&OAc(
bisMesOH&OAc(
Ra%o)
1j&OAc/bisC12&OAc/bisMesOH&OAc(=)91/6/3)
(
1
j&OAc(
bisC12&OAc( bisMesOH&OAc(
1
H-NMR of crude 1k-Cl (selectivity)
OAc
OAc
OAc
N
N
N
N
N
N
1
k&OAc(
bisIsopino&OAc(
1k&OAc(
bisMes&OAc(
Ra%o)
1k&OAc/bisIsopino&OAc/bisMes&OAc(=)92/3.5/4.5)
(
bisMes&OAc(
bisIsopino&OAc(
2
0
ꢀ

3
.2. Chloride imidazolium salts
1
H-NMR of 1a-Cl
Cl
500
N
N
0
10.0
5.0
ppm (t1)
1
3
1
C{ H}-NMR of 1a-Cl
70000
60000
50000
40000
30000
20000
10000
0
Cl
N
N
-
10000
150
100
50
0
ppm (t1)
2
1
ꢀ

1
H-NMR of 1b-Cl
Cl
N
N
1
3
1
C{ H}-NMR of 1b-Cl
Cl
N
N
2
2
ꢀ

1
H-NMR of 1c-Cl
Cl
N
N
1
3
1
C{ H}-NMR of 1c-Cl
Cl
N
N
2
3
ꢀ

1
H-NMR of 1d-Cl
Cl
N
N
1
3
1
C{ H}-NMR of 1d-Cl
Cl
N
N
2
4
ꢀ

1
H-NMR of 1e-Cl
Cl
N
N
50000
0
10.0
5.0
ppm (t1)
1
3
1
C{ H}-NMR of 1e-Cl
Cl
N
N
2
5
ꢀ

1
H-NMR of 1f-Cl
Cl
N
N
1
3
1
C{ H}-NMR of 1f-Cl
Cl
N
N
2
6
ꢀ

1
H-NMR of 1g-Cl
Cl
N
N
1
3
1
C{ H}-NMR of 1g-Cl
Cl
N
N
2
7
ꢀ

1
H-NMR of 1h-Cl
Cl
N
N
1
3
1
C{ H}-NMR of 1h-Cl
Cl
N
N
2
8
ꢀ

1
H-NMR of 1i-Cl
Cl
N
N
1
3
1
C{ H}-NMR of 1i-Cl
Cl
N
N
2
9
ꢀ