42
H.-W. Suh et al. / Polyhedron 84 (2014) 37–43
resulting solid was recrystallized at room temperature from THF–
pentane to give orange crystals suitable for X-ray crystallography.
1H NMR (C6D6, 500 MHz): d 8.31(2H, ddd, ArH, J = 9.6, 7.4,
2.0 Hz), 8.08 (1H, d, ArH, J = 7.3 Hz), 7.77 (1H, d, ArH, J = 7.1 Hz),
7.66 (1H, app t, ArH, J = 6.5 Hz), 7.37 (2H, t, ArH, J = 7.3 Hz), 7.26
(2H, m, ArH), 7.15–6.86 (16H, ArH), 6.64 (1H, t, ArH, J = 7.3 Hz),
6.53 (2H, td, ArH, J = 7.4, 1.4 Hz), 3.96 (2H, br p, C8H13, J = 7.2 Hz),
3.72 (1H, dt, C8H13, J = 15.3, 7.8 Hz), 2.09 (1H, m, C8H13), 1.92 (2H,
m, C8H13), 1.84 (1H, m, C8H13), 1.36 (3H, s, SiMe), 1.35–1.17 (3H,
C8H13), 1.09–0.97 (3H, C8H13). 13C{1H} NMR (C6D6, 126 MHz): d
160.0 (d, J = 56.6 Hz), 157.6 (dd, J = 68.1, 5.2 Hz), 148.0 (d,
J = 45.7 Hz), 146.5 (dd, J = 41.0, 3.0 Hz), 139.1 (m), 138.5 (d,
J = 18.8 Hz), 136.9 (d, J = 16.1 Hz), 136.5 (dd, J = 21.5, 6.7 Hz),
135.2 (d, J = 23.9 Hz), 133.1, 132.7 (d, J = 21.2 Hz), 132.5 (d,
J = 12.9 Hz), 132.2 (d, J = 10.4 Hz), 132.0, 131.9 (d, J = 9.4 Hz),
130.1 (dd, J = 51.3, 1.7 Hz), 129.1 (d, J = 49.6 Hz), 128.8 (d,
J = 4.2 Hz), 128.4, 99.3, 66.9, 65.8 (dd, J = 15.5, 4.3 Hz), 32.6 (d,
J = 10.1 Hz), 31.7 (d, J = 5.0 Hz), 30.7 (d, J = 5.7 Hz), 29.5 (d,
J = 8.1 Hz), 24.1, 3.65 (d, J = 5.8 Hz). 31P{1H} NMR (C6D6,
202.0 MHz): d 52.1 (d, JPP = 117.0 Hz), 36.9 (d, JPP = 116.9 Hz).
29Si{1H} NMR (99 MHz, C6D6) d 52.9 (dd, JSiP = 21.5, 15.5 Hz). Anal.
Calc. for C45H44NiP2Si: C, 73.68; H, 6.05. Found: C, 73.43; H, 5.93%.
1H NMR (C6D6, 500 MHz): d 7.98 (2H, q, ArH, J = 5.6 Hz), 7.86 (1H,
d, ArH, J = 7.4 Hz), 7.33–7.30 (4H, overlapping resonances), 7.24–
6.98 (17H, overlapping resonances under C6D6), 6.92 (2H, t, ArH,
J = 7.5 Hz), 6.80 (2H, t, ArH, J = 7.7 Hz), 0.75 (3H, s, SiMe). 13C{1H}
NMR (C6D6, 151 MHz):
d 153.9 (t, J = 31.1 Hz), 144.9 (t,
J = 27.3 Hz), 135.6 (t, J = 20.1 Hz), 133.6 (t, J = 6.6 Hz), 132.7 (t,
J = 6.0 Hz), 132.0 (t, J = 12.5 Hz), 131.7, 130.1, 129.8, 129.3 (t,
J = 3.1 Hz), 128.9, 128.8, 6.15. 31P{1H} NMR (C6D6, 162 MHz): d 59.0.
4.3.4. (CyPSiP)Ni( 2-BH4) (6)
j
A solution of (CyPSiP)NiH (30.0 mg, 0.0462 mmol) in 5 mL ben-
zene was charged with 2 equivalents of BH3ꢀTHF solution (1.0 M
in THF, 92
lL, 0.092 mmol) at room temperature. The solution
was left to sit for ten minutes. Subsequently, the solution was fil-
tered through Celite and the volatiles were removed. The resulting
orange residue was recrystallized from pentane at ꢁ35 °C to yield 6
as bright orange needles in 57% yield (17.4 mg, 0.0262 mmol).
Recrystallization of 6 from concentrated pentane solution at room
temperature gave red crystals suitable for X-ray crystallography.
1H NMR (C6D6, 400 MHz): d 7.96 (2H, d, ArH, J = 7.4 Hz), 7.44
(2H, d, ArH, J = 7.8 Hz), 7.29 (2H, t, ArH, J = 7.3 Hz), 7.19 (2H, t,
ArH, J = 7.4 Hz), 2.80 (2H, t, CyH, J = 12.6 Hz), 2.63 (2H, d, CyH,
J = 12.3 Hz), 2.34 (2H, m, CyH), 2.19 (2H, m, CyH), 2.10–2.07 (2H,
CyH, overlapping resonances), 1.98 (2H, d, CyH, J = 12.3 Hz), 1.83
(2H, d, CyH, J = 9.9 Hz), 1.64–1.02 (29H, overlapping resonances,
CyH and BH4), 0.94–0.72 (5H, overlapping resonances), 0.89 (3H,
s, SiMe). 13C{1H} NMR (C6D6, 101 MHz): d 157.6 (t, J = 28.0 Hz),
141.7 (t, J = 22.0 Hz), 132.3 (t, J = 11.2 Hz), 130.4, 130.3, 128.5,
35.0 (t, J = 10.6 Hz), 34.5 (t, J = 10.7 Hz), 30.5, 29.5, 28.4, 27.7 (t,
J = 7.1 Hz), 27.7, 27.4 (t, J = 7.2 Hz), 27.4, 27.2 (t, J = 5.6 Hz), 27.0,
26.6, 8.7 (t, J = 1.7 Hz). 31P{1H} NMR (C6D6, 162 MHz): d 68.5 4.
29Si{1H} NMR (C6D6, 99 MHz): d 62.09 (t, J = 27.7 Hz).
4.3.2. (PhPSiP)2Ni (2)
A solution of PhPSiHP (123.6 mg, 0.218 mmol) in 5 mL of toluene
at room temperature was added to a solution of Ni(COD)2 (30.0 mg,
0.109 mmol) in 5 mL toluene under an N2 atmosphere. The
reaction mixture was allowed to stir at room temperature for
twelve hours. The volatiles were removed under reduced pressure,
and the remaining solids were washed with pentane (4 ꢂ 3 mL) to
give 2 as a yellow powder in 53% yield (68.3 mg, 0.057 mmol). The
resulting solid was recrystallized at room temperature from
toluene–pentane to give yellow crystals suitable for X-ray
crystallography.
4.4. Representative procedures for catalysis
1H NMR (C6D6, 400 MHz): d 7.58 (1H, d, ArH, J = 7.4 Hz), 7.53
(2H, t, ArH, J = 8.5 Hz), 7.45 (3H, t, ArH, J = 7.4 Hz), 7.34 (1H, d,
ArH, J = 7.2 Hz), 7.26 (1H, t, ArH, J = 6.6 Hz), 7.2–6.68 (42H, ArH),
6.62 (2H, t, ArH, J = 6.5 Hz), 6.43 (2H, t, ArH, J = 7.7 Hz), 6.32 (1H,
t, ArH, J = 6.2 Hz), 6.25 (1H, t, ArH, J = 6.0 Hz), 1.33 (3H, s, SiMe),
0.93 (3H, s, SiMe). 13C{1H} NMR (C6D6, 126 MHz): d 161.0 (d,
J = 61.4 Hz), 156.6 (d, J = 42.7 Hz), 155.6 (dd, J = 79.7, 57.1 Hz),
150.7 (t, J = 47.3 Hz), 146.8 (d, J = 36.7 Hz), 141.8 (apparent t,
J = 16.8 Hz), 140.6 (d, J = 11.1 Hz), 140.4 (d, J = 16.9 Hz), 139.9
(dd, J = 33.7, 17.2 Hz), 139.8 (dd, J = 22.5, 9.8 Hz), 138.9–138.3
(overlapping resonances), 138.0 (dd, J = 32.6, 5.4 Hz), 136.5 (d,
J = 13.3 Hz), 135.7 (d, J = 12.3 Hz), 135.3, 134.8 (d, J = 12.0 Hz),
134.3 (dd, J = 49.1, 18.8 Hz), 133.4 (d, J = 9.7 Hz), 133.0 (d,
J = 9.9 Hz), 132.3 (d, J = 22.8 Hz), 132.1, 132.1, 131.2 (d,
J = 21.5 Hz), 131.1, 130.7, 130.6, 129.8, 129.2, 128.8, 127.6, 127.4,
127.2, 127.2, 126.7, 126.6, 11.0 (dd, J = 14.5, 10.4 Hz), 3.54 (t,
J = 6.4 Hz). 31P{1H} NMR (C6D6, 202 MHz): d 58.3 (dd, J = 143.2,
91.0 Hz), 51.9 (dd, J = 143.8, 89.6 Hz), 38.7 (t, J = 90.7 Hz), ꢁ7.66.
29Si{1H} NMR (C6D6, 99 MHz): d 58.4, 44.1. Anal. Calc. for C74H62-
NiP4Si2: C, 74.69; H, 5.25. Found: C, 74.60; H, 5.52%.
4.4.1. Isomerization of alkenes (1-hexene and 1,5-cyclooctadiene)
A solution of 1 (0.3–0.5 mg) in 0.5 mL C6D6 was charged with
100 equivalents of the alkene at room temperature in a screw
cap NMR tube. The formation of products over time was monitored
by 1H NMR spectroscopy until all starting materials were con-
sumed (1,5-cyclooctadiene), or the relative ratio of the isomers
reached equilibrium (1-hexene). See the Supporting information
for more details.
4.4.2. Hydroboration of pinacolborane
A solution of 1 mol% 1 (1.0 mg, 0.0014 mmol), HB(pin) (9.9 lL,
0.050 mmol) and 1,3,5-trimethoxybenzene (11.5 mg) in 0.6 mL of
C6D6 was added to a J. Young NMR tube. The sample was degassed
using three freeze–pump–thaw cycles and 1 atm of CO2 was intro-
duced via a Schlenk line. The formation of products over time was
monitored using 1H NMR spectroscopy. See the Supporting infor-
mation for more details.
Acknowledgement
4.3.3. (PhPSiP)Ni( 2-BH4) (5)
j
We acknowledge support from the National Science Foundation
through Grant CHE-1150826. We are grateful to Timothy Schmeier
and Michael Takase for assistance with X-ray crystallography.
A solution of 1 (25.0 mg, 0.0341 mmol) in 2 mL benzene was
charged with 3 equivalents of BH3ꢀTHF solution (1.0 M in THF,
82 lL, 0.082 mmol) at room temperature. The solution was left to
sit for ten minutes. Subsequently, the solution was filtered through
Celite and the volatiles were removed. The resulting dark brown oil
was washed with cold diethyl ether and dried under vacuum to
give 4 as a brown solid in 77% yield (16.7 mg, 0.0261 mmol). The
limited solubility of this species in all common organic solvents
prevented us from isolating it in a pure form or recording a
29Si{1H} NMR spectrum.
Appendix A. Supplementary data
CCDC 998687–998689 contain the supplementary crystallo-
graphic data for 1, 2 and 6. These data can be obtained free of
from the Cambridge Crystallographic Data Centre, 12 Union Road,