Inorganic Chemistry
Article
Cquat.), 130.3 (d, JC−P = 1.7 Hz, CHarom.), 130.7 (s, CHarom.), 134.5 (d,
JC−P = 1.9 Hz, CHarom.), 136.2 (d, JC−P = 3.9 Hz, Cquat.), 137.1 (d, JC−P
= 35.9 Hz, Cquat.), 138.6 (d, JC−P = 20.0 Hz, Cquat.), 143.8 (s, CHarom.);
31P{1H} (121.49 MHz, C6D6) δ = 7.9.
C
quat.), 144.3 (s, Cquat.), 147.8 (s, Cquat.), 156.5 (d, JC−P = 16.0 Hz,
Cquat.); 11B{1H} (128.4 MHz, 298 K, CDCl3) δ = 16.2; 31P{1H} (162.0
MHz, 298 K, CDCl3) δ = 17.4.
Compound 2-BFlu. 375 μL of n-BuLi (1.60 M in hexanes, 0.60
mmol) were added dropwise to 222 mg (0.60 mmol) of 1-iodo-8-
diisopropylphosphinonaphtalene in diethylether (2.3 mL) at −50 °C,
and the reaction mixture was stirred at this temperature for 30 min.
The solution was then filtered off and the resulting yellow solid was
washed with diethylether (2 × 1 mL) at −50 °C. The solid was then
dissolved in toluene (2.3 mL) and a toluene solution (1.6 mL) of
chloroborafluorene (119.2 mg, 0.6 mmol) was added at −78 °C. After
warming to rt and stirring overnight, the volatiles were removed under
a vacuum; the residue was dissolved in pentane (5 mL) and filtered
through a plug of Celite. After concentration of the solution,
compound 2-BFlu was obtained at −40 °C as colorless crystals
suitable for X-ray diffraction analysis in 52% yield. mp 172 °C. HRMS
(CI-CH4): exact mass calculated for C28H28BP,421.2100;
Compound 2-BCy2. 375 μL of n-BuLi (1.60 M in hexanes, 0.60
mmol) were added dropwise to 222 mg (0.60 mmol) of 1-iodo-8-
diisopropylphosphinonaphtalene in solution in diethylether (2.3 mL)
at −50 °C. After stirring 30 min at this temperature, the solution was
filtered off and the resulting yellow solid was washed with diethylether
(2 × 1 mL) at −50 °C. The solid was then dissolved in 2.3 mL of
toluene, and dicyclohexylchloroborane (1.0 M in hexanes, 0.6 mmol,
600 μL) was added dropwise at −78 °C. The reaction mixture was
stirred at rt overnight. The volatiles were then removed under a
vacuum; the residue was dissolved in pentane (5 mL) and filtrated
through a plug of Celite. Compound 2-BCy2 was obtained as colorless
crystals suitable for X-ray diffraction analysis from a concentrated
solution of pentane −40 °C in 56% yield. mp 176 °C. HRMS m/z (CI,
CH4): exact mass calculated C48H42BP,421.3195; found, 421.3210;
elementary analysis: calculated C,79.99; H,10.07 found C,80.21;
1
found,421.2095. H NMR (300.16 MHz, C6D6) δ = 0.59 (dd, 6H,
3JH−P = 15.5 Hz, 3JH−H = 7.1 Hz, CH3iPr), 0.65 (dd, 6H, 3JHP = 14.4 Hz,
3JHH = 7.1 Hz, CH3iPr), 2.07 [(pseudo)sept-d, 2H, JH−P = 10.3 Hz,
3
1
3
H,10.47. H NMR (300.18 MHz, C6D6) δ = 0.81 (dd, 6H, JH−P
=
3JH−H = 7.1 Hz, CHiPr], 7.09−7.18 (m, 2H, Harom.), 7.25−7.40 (m, 8H,
Harom.), 7.52−7.56 (m, 1H, Harom.), 7.80−7.85 (m, 1H, Harom.), 7.91−
7.97 (m, 2H, Harom.); 13C {1H} (125.81 MHz, C6D6) δ = 17.7 (d, 2JC−P
13.2 Hz, 3JH−H = 7.1 Hz, CH3iPr), 0.95 (dd, 6H, 3JH−P = 13.2 Hz, 3JH−H
= 7.1 Hz, CH3iPr), 1.16−1.61 (m, 12H, HCy), 1.70−1.88 (m, 6H, HCy),
3
1.96−2.20 (m, 4H, HCy), 2.27 [(pseudo)sept-d, 2H, JH−H = 7.1 Hz,
1
2JH−P = 8.3 Hz, CHiPr], 7.14−7.26 (m, 2H, Harom.), 7.49−7.59 (m, 2H,
= 1.7 Hz, CH3iPr), 18.0 (s, CH3iPr), 23.1 (d, JC−P = 26.4 Hz, CHiPr),
120.1 (d, JC−P = 1.0 Hz, CHarom.), 124.0 (d, JC−P = 1.4 Hz, CHarom.),
125.2 (d, JC−P = 7.4 Hz, CHarom.), 126.1(d, JC−P = 2.8 Hz, CHarom.),
127.0 (d, JCP = 2.6 Hz, CHarom.), 128.35 (br, CHarom.), 129.2 (d, JC−P
2.2 Hz, CHarom.), 129.5 (d, JC−P = 14.0 Hz, CHarom.), 129.75 (d, JC−P
51.4 Hz, Cquat.), 131.3 (d, JC−P = 2.2 Hz, CHarom.), 132.1 (d, JC−P = 2.4
Hz, CHarom.), 133.1 (d, JC−P = 9.3 Hz, Cquat.), 146.3 (d, JC−P = 28.3 Hz,
Cquat.), 150.4 (d, JC−P = 5.7 Hz, Cquat.), 155.7 (br, Cquat.), one
quaternary, in α position of the boron atom is not observed; 11B{1H}
(96.3 MHz, CDCl3) δ = −8.5; 31P{1H} (121.49 MHz, CDCl3) δ =
25.1.
3
Harom.), 7.72 (d-mult, 1H, JH−H = 6.1 Hz, Harom.), 7.76 (d-mult, 1H,
3JH−H = 7.8 Hz, Harom.); 13C{1H} (125.81 MHz, C6D6) δ = 18.3 (d,
2JC−P = 0.8 Hz, CH3iPr), 19.1 (s, CH3iPr), 22.6 (d, JC−P = 18.0 Hz,
1
=
=
CHiPr), 28.2 (s, CH2Cy), 29.7 (s, CH2Cy), 30.2 (s, CH2Cy), 32.1 (d, JC−P
= 7.5 Hz, CH2Cy), 33.8 (d, JC−P = 6.1 Hz, CH2Cy), 123.3 (d, JC−P = 1.8
Hz, CHarom.), 124.8 (d, JC−P = 6.7 Hz, CHarom.), 126.5 (s, CHarom.),
127.9 (d, JC−P = 2.4 Hz, CHarom.), 128.7 (d, JC−P = 16.4 Hz, CHarom.),
130.2 (d, JC−P = 45.6 Hz, Cquat.), 130.9 (d, JC−P = 2.1 Hz, CHarom.),
132.7 (d, JC−P = 9.2 Hz, Cquat.), 145.5 (d, JC−P = 29.6 Hz, Cquat.), the
three carbon atoms in α position of the boron atom are not observed;
11B{1H} (128.4 MHz, CDCl3) δ = 0.1; 31P{1H} (121.49 MHz, CDCl3)
δ = 23.4.
Crystallographic Analyses. Crystallographic data were collected
at 193(2) K on a Bruker-AXS Kappa APEXII Quazar diffractometer
(for 2-BCy2 and 2-BFlu) and on a Bruker−AXS CCD 1000
diffractometer (for 2-BMes2), with Mo Kα radiation (λ = 0.71073
Å) using an oil-coated shock-cooled crystal. Phi- and omega-scans
were used. Semiempirical absorption correction was employed.31 The
structures were solved by direct methods (SHELXS-97)32 and refined
using the least-squares method on F2.33 All non-H atoms were refined
with anisotropic displacement parameters. The H atoms were refined
isotropically at calculated positions using a riding model with their
isotropic displacement parameters constrained to be equal to 1.5 times
the equivalent isotropic displacement parameters of their pivot atoms
for terminal sp3 carbon and 1.2 times for all other carbon atoms.
Computational Studies. Calculations were carried out with the
Gaussian 09 program34 at the DFT level of theory using the hybrid
functional B3PW91.35 B3PW91 is Becke’s 3 parameters functional,
with the nonlocal correlation provided by the Perdew 91 expression.
All the atoms have been described with a 6-31G(d,p) double-ζ basis
set.36 Geometry optimizations were carried out without any symmetry
restrictions, the nature of the extrema (minima or transition state) was
verified with analytical frequency calculations. All total energies and
Gibbs free energies have been zero-point energy (ZPE) and
temperature corrected using unscaled density functional frequencies.
Electronic structure of the different complexes was studied using
natural bond orbital analysis (NBO-5 program).37 The NBO orbital
(σBP) obtained from first-order NBO analysis was plotted by using the
molecular graphic program NBOView 1.1.38 The electron density of
the optimized structures was subjected to an atoms in molecules
analysis (QTAIM analysis)39 using AIMAll software.40
Compound 2-BMes2. 235 μL of n-BuLi (2.50 M in hexanes,0.60
mmol) and 158 mg (0.60 mmol) of dimesitylfluoroborane in solution
of toluene (2 mL) were successively added at −50 °C and −78 °C to a
1-iodo-8-diisopropylphosphinonaphtalene solution (222 mg, 0.6
mmol) in toluene (2 mL). After warming to rt, the volatiles were
removed under a vacuum, the residue was dissolved in pentane (2 × 5
mL), and the salts were removed by filtration. After concentration of
the solution at rt, compound 2-BMes2 is obtained as colorless crystals
suitable for X-ray diffraction analysis in 58% yield. mp 176 °C. m/z
1
(EI, 70 eV): 492 [M]+. H NMR (400.1 MHz, CDCl3) δ = 0.45 (dd,
3
3
3H, JH−P = 12.0 Hz, JH−H = 7.2 Hz, CH3i‑Pr), 1.12 (s, 3H, CH3Mes),
1.13 (dd, 3H, 3JH−3P = 12.0 Hz, 3JH−H = 7.2 Hz, CH3i‑Pr), 1.34 (dd, 3H,
3JH−P = 12,0 Hz, JH−H = 7.2 Hz, CH3i‑Pr), 1.36 (dd, 3H, JH−P = 12,0
3
3
Hz, JH−H = 7.2 Hz, CH3i‑Pr), 1.86 (s, 3H, CH3Mes), 2.01 (s, 3H,
CH3Mes), 2.24 (s, 3H, CH3Mes), 2.26 (s, 3H, CH3Mes), 2.33 (s, 3H,
2
3
CH3Mes), 2.46 [(pseudo)sept-d, 1H, JH−P = 14.0 Hz, JH−H = 7.2 Hz,
2
3
CHi‑Pr], 2.70 [(pseudo)sept-d, 1H, JH−P = 14,0 Hz, JH−H = 7.2 Hz,
CHi‑Pr], 6.50 (s, 1H, HMes), 6.79 (s, 1H, HMes), 6.82 (s, 2H, HMes), 7.46
(m, 2H, Harom.), 7.58 (dd, 1H, 3JH−H = 6,6 Hz, 3JH−H = 7.6 Hz, Harom.),
7.75 (dd, 1H, 3JH−H = 7.2 Hz, 4JH−H = 1.9 Hz, Harom.), 7.78 (pseudo-t,
3
3
3
1H, JH−H = 6.6 Hz, JH−P = 6.6 Hz, Harom.), 8.04 (d, 1H, JH−H = 7.6
Hz, Harom.); 13C{1H} (101.6 MHz, 298 K, CDCl3) δ = 18.1 (s,
2
CH3i‑Pr), 19.2 (s, CH3i‑Pr), 20.0 (s, CH3i‑Pr), 21.2 (d, JC−P = 3.0 Hz,
CH3i‑Pr), 21.3 (s, 2C, CH3Mes), 25.8 (s, CH3Mes), 26.0 (d, JC−P = 2.0
Hz, CH3Mes), 26.3 (s, CH3Mes), 26.6 (s, CH3Mes), 26.8 (d, 1JC−P = 16.0
Hz, CHi‑Pr), 30.3 (s, CHi‑Pr), 125.0 (d, 4JC−P = 5.0 Hz, CHNapht), 125.3
(s, CHNapht), 127.9 (d, JC−P = 1.0 Hz, CHNapht), 128.4 (s, CHMes),
128.4 (s, CHMes), 128.9 (s, Cquat.), 129.2 (s, CHNapht), 129.7 (d, JC−P
=
=
=
ASSOCIATED CONTENT
* Supporting Information
3
■
4 Hz, CHMes), 129.8 (s, CHMes), 130.3 (s, CHMes), 131.1 (d, JC−P
S
2
1.0 Hz, CHNapht), 132.9 (d, JC−P = 14.0 Hz, Cquat.), 133.0 (d, JC−P
Synthetic procedures and analytical data including NMR
spectra for 1, 2-BCy2, 2-BMes2, and 2-BFlu; X-ray crystallo-
graphic data for CCDC 923615 (2-BCy2), 923616 (2-BMes2),
15.0 Hz, CHNapht), 135.1 (s, Cquat.), 136.2 (d, JC−P = 4.0 Hz, Cquat.),
140.7 (d, JC−P = 4 Hz, Cquat.), 142.2 (d, JC−P = 10.0 Hz, Cquat.), 142.5
(d, JC−P = 9.0 Hz, Cquat.), 143.9 (d, JC−P = 33 Hz, Cquat.), 144.0 (s,
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dx.doi.org/10.1021/ic4003466 | Inorg. Chem. 2013, 52, 4714−4720