S.J. Geier et al. / Inorganic Chemistry Communications 9 (2006) 788–791
789
0.16 mmol). The reaction was stirred for 3 days at which
point a dark brown precipitate was collected by suction
filtration. The solid was washed with toluene (1 mL) and hex-
ane (3 · 3 mL) to afford 3. Yield: 95 mg (81%) of a red-
[M] + EBR2
E = H, BR2
EH
[M]
E
[M]
E
BR2
R'
H
1
brown solid. Spectroscopic NMR data (in CDCl3): H d:
7.35-7.27 (ov m, 6H, Ar), 6.70-6.61 (ov m, 4H, Ar), 5.17
(m, 2H, g6-C6H4O2), 4.99 (m, 2H, g6-C6H4O2), 3.11 (sept,
J = 7 Hz, 4H, CH), 1.53 (s, 6H, CH3), 1.38 (d, J = 7 Hz,
12H, CH3), 1.06 (d, J = 7 Hz, 12H, CH3); 11B d: 13.7;
13C{1H} d: 154.0, 151.8, 150.9, 140.3, 138.8, 127.8, 124.1,
118.6, 118.2, 84.1 (d, JRh–C = 6 Hz), 79.8 (d, JRh–
C = 4 Hz), 28.0, 24.6, 24.2, 18.8. Anal. calcd. for
C40H48BN2O4Rh: C 65.40, H 6.60, N 3.81; found C
65.84, H 6.91, N 3.81.
R'
H
[M]
H
H
BR2
E
R'
R2B
Scheme 1.
Guelph Chemical Laboratories (Guelph, ON). All reac-
tions were carried out under an atmosphere of dinitrogen.
Preparation of [Rh(j2-2,6-iPr2C6H3N@C(Me)C(Me)@N-
2,6-iPr2C6H3)(l-Cl)]2 (1)
General procedure for the catalyzed borylation of vinylarenes
To a toluene solution (4 mL) of [RhCl(coe)2]2 (coe = cis-
cyclooctene, 150 mg, 0.21 mmol) was added a toluene solu-
tion (1 mL) of (2E)-N-((E)-3-(2,6-diisopropylphenyli-
mino)butan-2-ylidene)-2,6- diisopropylbenzenamine (169 mg,
0.42 mmol). The mixture was heated to reflux for 18 h at
which point solvent was removed under vacuum. The
resulting solid was washed with hexane (2 · 1 mL) to afford
1. Yield: 175 mg (77%) of a red-brown solid. Spectroscopic
NMR data (in C6D6): 1H d: 7.35 (t, J = 8 Hz, 4H, Ar), 7.22
(d, J = 8 Hz, 8H, Ar), 3.25 (sept, J = 7 Hz, 8H, CH), 1.55
(d, J = 7 Hz, 24H, CH3), 0.99 (d, J = 7 Hz, 24H, CH3),
À0.53 (s, 12H, CH3); 13C{1H} d: 155.8, 149.1, 140.5,
126.4, 123.0, 28.4, 24.2, 23.5, 19.0. Anal. calcd. for
C56H80Cl2N4Rh2: C 61.92, H 7.44, N 5.16; found C
61.60, H 7.73, N 5.09.
The appropriate borylation reagent (1.2 equivalents), in
0.5 mL of C6D6, was added to a 0.5 mL C6D6 solution of
1–3 (2 mol%) and the vinylarene. Reactions were allowed
to proceed for 18 h and then monitored by multinuclear
NMR spectroscopy.
X-ray crystallography
Crystals of 1 were grown from a saturated hexane solu-
tion at À25 ꢁC. Single crystals were coated with Paratone-
N oil, mounted using a glass fibre and frozen in the cold
stream of the goniometer. A hemisphere of data was col-
lected on a Bruker AXS P4/SMART 1000 diffractometer
using x and h scans with a scan width of 0.3ꢁ and 10 s
exposure time. The detector distance was 5 cm. The data
were reduced [13] and corrected for absorption [14]. The
structure was solved by direct methods and refined by
full-matrix least squares on F2 [15]. All non-hydrogen
atoms were refined anisotropically. Hydrogen atoms were
located in Fourier difference maps and refined isotropi-
cally. Crystals of 3 were grown from a saturated THF
solution at À25 ꢁC. Single crystals were coated with
Paratone-N oil, mounted using a 20 lm cryo-loop and
frozen in the cold nitrogen stream of the goniometer. A
hemisphere of data was collected on a Bruker AXS P4/
SMART 1000 diffractometer using x and h scans with a
scan width of 0.3 ꢁ and 30 s exposure times. The detector
distance was 5 cm. The data were reduced (SAINT) and
corrected for absorption (SADABS). The structure was
solved by direct methods and refined by full-matrix least
squares on F2 (SHELXTL). One of the THF molecules
was disordered and the site occupancy fixed at 0.5 for
C(60), C(62), C(64), C(70), C(71) and C(72). All non-
hydrogen atoms were refined anisotropically. Distinction
between oxygen and carbon atoms in the THF molecules
was not successful and all positions were refined as C
atoms. Hydrogen atoms were included in calculated posi-
tions and refined using a riding model. The THF hydrogen
atoms were omitted.
Preparation of [Rh(acac)(j2-2,6-i Pr2C6H3N@C(Me)C-
(Me)@N-2,6-iPr2C6H3)] (2)
To a toluene solution (4 mL) of Rh(acac)(coe)2 (200 mg,
0.47 mmol) was added a toluene solution (1 mL) of (2E)-N-
((E)-3-(2,6-diisopropylphenylimino)butan-2-ylidene)-2,6-
diisopropylbenzenamine (191 mg, 0.47 mmol). The mixture
was heated to reflux for 18 h at which point solvent was
removed under vacuum. The resulting solid was washed
with cold hexane (1 mL) to afford 2. Yield: 235 mg (82%)
of a red-brown solid. Spectroscopic NMR data (in C6D6):
1H d: 7.49–7.44 (ov m, 2H, Ar), 7.36-7.33 (ov m, 4H, Ar),
4.58 (s, 1H, CH@C), 3.50 (sept, J = 7 Hz, 4H, CH), 1.58
(s, 6H, C(O)CH3), 1.50 (d, J = 7 Hz, 12H, CH3), 1.16 (d,
J = 7 Hz, 12H, CH3), À0.11 (s, 6H, CH3); 13C{1H} d:
182.9, 159.6, 149.2, 141.2, 126.4, 123.0, 98.1, 28.7, 26.5,
24.4, 23.4, 19.1. Anal. calcd. for C33H47N2O2Rh: C 65.32,
H 7.82, N 4.62; found C 64.95, H 7.87, N 4.42.
Preparation of [Rh(catBcat)(j2-2,6-iPr2C6H3N@C(Me)-
C(Me)@N-2,6-iPr2C6H3] (3)
To a toluene solution (3 mL) of 2 (100 mg, 0.16 mmol)
was added a toluene solution (1 mL) of B2cat3 (57 mg,