Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S160053680100294X/ob6030sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S160053680100294X/ob6030Isup2.hkl |
CCDC reference: 159873
According the literature procedure of Wolfe & Livinghouse (1998), the enantioselective alkylation of the phosphine–borane (I) with the lithium–sparteine complex afforded the desired C2-symmetric diphosphine in 54% yield and 98.5% ee, contaminated with 5% of the meso diastereoisomer. Recrystallization from dichloromethane/ether afforded the enantio- and diastereomerically pure (>99%) bis(phosphine–borane) (II). Optical rotation of (II): [a]D = +127.6 (c 2.78, CHCl3).
The title compound, (II), is quite stable and can be stored for months on the bench, whitout any significant decomposition. It might be sensitive to the X-ray especially since it was a linear decay, which was corrected. H atoms were constrained to the parent site using a riding model; SHELXL96 defaults, C—H = 0.93–0.97 Å and B—H = 0.96 Å. The isotropic factors, Uiso, were adjusted to 150% of the value of the parent site for methyl and B—H H atoms and 120% for other H atoms.
Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: NRC-2 and NRC-2A (Ahmed et al., 1973); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL96 (Sheldrick, 1996); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXL96.
C28H42B2P2 | Dx = 1.092 Mg m−3 |
Mr = 462.18 | Cu Kα radiation, λ = 1.54056 Å |
Orthorhombic, P212121 | Cell parameters from 25 reflections |
a = 7.380 (6) Å | θ = 20.0–21.0° |
b = 13.515 (6) Å | µ = 1.48 mm−1 |
c = 28.189 (14) Å | T = 293 K |
V = 2812 (3) Å3 | Block, colourless |
Z = 4 | 0.83 × 0.22 × 0.14 mm |
F(000) = 1000.0 |
Nonius CAD-4 diffractometer | 4737 reflections with I > 2σ(I) |
Radiation source: normal-focus xray tube | Rint = 0.062 |
Graphite monochromator | θmax = 69.8°, θmin = 3.1° |
ω scans | h = −8→8 |
Absorption correction: integration (ABSORP in NRCVAX; Gabe et al., 1989) | k = −16→16 |
Tmin = 0.539, Tmax = 0.830 | l = −34→34 |
30802 measured reflections | 5 standard reflections every 60 min |
5320 independent reflections | intensity decay: 21.7% |
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.035 | w = 1/[σ2(Fo2) + (0.0491P)2P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.088 | (Δ/σ)max = 0.001 |
S = 0.98 | Δρmax = 0.21 e Å−3 |
5320 reflections | Δρmin = −0.22 e Å−3 |
298 parameters | Extinction correction: SHELXL96, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 restraints | Extinction coefficient: 0.0028 (2) |
Primary atom site location: structure-invariant direct methods | Absolute structure: Flack (1983), 2274 Friedel pairs |
Secondary atom site location: difference Fourier map | Absolute structure parameter: −0.004 (18) |
C28H42B2P2 | V = 2812 (3) Å3 |
Mr = 462.18 | Z = 4 |
Orthorhombic, P212121 | Cu Kα radiation |
a = 7.380 (6) Å | µ = 1.48 mm−1 |
b = 13.515 (6) Å | T = 293 K |
c = 28.189 (14) Å | 0.83 × 0.22 × 0.14 mm |
Nonius CAD-4 diffractometer | 4737 reflections with I > 2σ(I) |
Absorption correction: integration (ABSORP in NRCVAX; Gabe et al., 1989) | Rint = 0.062 |
Tmin = 0.539, Tmax = 0.830 | 5 standard reflections every 60 min |
30802 measured reflections | intensity decay: 21.7% |
5320 independent reflections |
R[F2 > 2σ(F2)] = 0.035 | H-atom parameters constrained |
wR(F2) = 0.088 | Δρmax = 0.21 e Å−3 |
S = 0.98 | Δρmin = −0.22 e Å−3 |
5320 reflections | Absolute structure: Flack (1983), 2274 Friedel pairs |
298 parameters | Absolute structure parameter: −0.004 (18) |
0 restraints |
Experimental. To a solution of (-)-sparteine (0.65 ml, 2.85 mmole) and t-butylphenylphosphine-borane (I) (453 mg, 2.52 mmole) in 15 ml of ether at -78°C was added n-butyllithium (2.00 M in hexanes, 1.30 ml, 2.52 mmole). The reaction was warmed to room temperature and stirred for 1 h, then cooled back to -78°C. The α,α'-dibromo-o-xylene (300 mg, 0.84 mmole) in THF (1.5 ml) was added drop wise. The resulting mixture was warmed to room temperature and stirred for 18 h. The reaction was quenched with 5% aqueous sulfuric acid (2 ml) and extracted with dichloromethane (3 x 10 ml). The combined organic phases were washed with water (5 ml) and brine (5 ml), then dried over MgSO4. The solvent was removed under reduced pressure. The desired diphosphine-borane product (II) (194 mg, 0.45 mmole, 54%) was obtained as a white solid after flash chromatography on silica gel (50% DCM/Hexane). The enantiomeric excess was determined to be 98.5% (140:1) by chiral HPLC analysis (Chiracel OD, 1 ml/min, 20% 2-propanol/hexanes, tR 5.93 (major), 7.19 (meso) 8.06 (minor)). The compound (II) was recrystallized from DCM/Ether. |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. A final verification of possible voids was performed using the VOID routine of the PLATON program (Spek, 1995). Refinement of F2 against ALL reflections. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating R-factor_obs etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.8903 (3) | 0.47164 (17) | 0.10781 (7) | 0.0446 (5) | |
H1 | 0.8054 | 0.4254 | 0.0977 | 0.054* | |
C2 | 0.8552 (3) | 0.52642 (16) | 0.14833 (7) | 0.0453 (5) | |
C3 | 0.9813 (4) | 0.59595 (18) | 0.16291 (7) | 0.0574 (6) | |
H3 | 0.9602 | 0.6335 | 0.1900 | 0.069* | |
C4 | 1.1381 (4) | 0.6092 (2) | 0.13715 (8) | 0.0646 (7) | |
H4 | 1.2224 | 0.6560 | 0.1470 | 0.077* | |
C5 | 1.1717 (4) | 0.55390 (18) | 0.09688 (7) | 0.0563 (6) | |
H5 | 1.2780 | 0.5641 | 0.0798 | 0.068* | |
C6 | 1.0494 (3) | 0.48394 (15) | 0.08181 (7) | 0.0431 (5) | |
C20 | 0.6796 (3) | 0.51271 (18) | 0.17506 (7) | 0.0516 (5) | |
H20A | 0.5830 | 0.5030 | 0.1522 | 0.062* | |
H20B | 0.6536 | 0.5732 | 0.1923 | 0.062* | |
P20 | 0.67580 (7) | 0.40987 (4) | 0.216968 (17) | 0.03970 (13) | |
B20 | 0.7582 (4) | 0.2900 (2) | 0.18879 (12) | 0.0648 (8) | |
H20C | 0.8852 | 0.2952 | 0.1819 | 0.097* | |
H20D | 0.6926 | 0.2783 | 0.1599 | 0.097* | |
H20E | 0.7382 | 0.2361 | 0.2103 | 0.097* | |
C21 | 0.8065 (3) | 0.44666 (16) | 0.26799 (7) | 0.0421 (5) | |
C22 | 0.8822 (3) | 0.3720 (2) | 0.29513 (8) | 0.0607 (7) | |
H22 | 0.8712 | 0.3067 | 0.2850 | 0.073* | |
C23 | 0.9728 (4) | 0.3916 (3) | 0.33640 (9) | 0.0829 (10) | |
H23 | 1.0199 | 0.3399 | 0.3543 | 0.099* | |
C24 | 0.9937 (4) | 0.4859 (3) | 0.35108 (10) | 0.0893 (11) | |
H24 | 1.0541 | 0.4989 | 0.3793 | 0.107* | |
C25 | 0.9261 (4) | 0.5631 (3) | 0.32451 (10) | 0.0792 (10) | |
H25 | 0.9451 | 0.6281 | 0.3342 | 0.095* | |
C26 | 0.8287 (3) | 0.54336 (19) | 0.28293 (8) | 0.0581 (6) | |
H26 | 0.7793 | 0.5951 | 0.2654 | 0.070* | |
C27 | 0.4377 (3) | 0.4015 (2) | 0.23797 (9) | 0.0557 (6) | |
C28 | 0.3217 (4) | 0.3616 (3) | 0.19679 (11) | 0.0863 (9) | |
H28A | 0.1970 | 0.3589 | 0.2064 | 0.129* | |
H28B | 0.3623 | 0.2965 | 0.1884 | 0.129* | |
H28C | 0.3335 | 0.4047 | 0.1699 | 0.129* | |
C29 | 0.4320 (4) | 0.3290 (2) | 0.27968 (12) | 0.0895 (10) | |
H29A | 0.5013 | 0.3552 | 0.3056 | 0.134* | |
H29B | 0.4824 | 0.2667 | 0.2700 | 0.134* | |
H29C | 0.3087 | 0.3196 | 0.2896 | 0.134* | |
C30 | 0.3662 (4) | 0.5016 (2) | 0.25378 (10) | 0.0746 (8) | |
H30A | 0.2432 | 0.4947 | 0.2644 | 0.112* | |
H30B | 0.3707 | 0.5471 | 0.2277 | 0.112* | |
H30C | 0.4394 | 0.5262 | 0.2793 | 0.112* | |
C60 | 1.0864 (3) | 0.42163 (17) | 0.03827 (7) | 0.0457 (5) | |
H60A | 1.0468 | 0.3544 | 0.0445 | 0.055* | |
H60B | 1.2161 | 0.4199 | 0.0328 | 0.055* | |
P60 | 0.97502 (7) | 0.46565 (4) | −0.015697 (17) | 0.03986 (13) | |
B60 | 0.7181 (4) | 0.4778 (3) | −0.00786 (10) | 0.0636 (8) | |
H60C | 0.6921 | 0.5327 | 0.0126 | 0.095* | |
H60D | 0.6709 | 0.4182 | 0.0059 | 0.095* | |
H60E | 0.6625 | 0.4886 | −0.0382 | 0.095* | |
C61 | 1.0838 (3) | 0.58073 (16) | −0.03153 (7) | 0.0442 (5) | |
C62 | 0.9838 (4) | 0.65275 (19) | −0.05435 (9) | 0.0648 (7) | |
H62 | 0.8602 | 0.6435 | −0.0590 | 0.078* | |
C63 | 1.0662 (6) | 0.7388 (2) | −0.07036 (11) | 0.0852 (10) | |
H63 | 0.9976 | 0.7866 | −0.0859 | 0.102* | |
C64 | 1.2485 (5) | 0.7537 (2) | −0.06343 (11) | 0.0820 (10) | |
H64 | 1.3034 | 0.8114 | −0.0743 | 0.098* | |
C65 | 1.3482 (4) | 0.6839 (2) | −0.04072 (9) | 0.0665 (7) | |
H65 | 1.4714 | 0.6941 | −0.0358 | 0.080* | |
C66 | 1.2683 (3) | 0.59781 (18) | −0.02485 (7) | 0.0499 (5) | |
H66 | 1.3384 | 0.5505 | −0.0095 | 0.060* | |
C67 | 1.0402 (3) | 0.37716 (16) | −0.06334 (7) | 0.0447 (5) | |
C68 | 0.9210 (5) | 0.2850 (2) | −0.05950 (10) | 0.0796 (9) | |
H68A | 0.9466 | 0.2413 | −0.0855 | 0.119* | |
H68B | 0.7957 | 0.3040 | −0.0604 | 0.119* | |
H68C | 0.9458 | 0.2517 | −0.0301 | 0.119* | |
C69 | 1.0073 (4) | 0.42745 (19) | −0.11134 (7) | 0.0598 (6) | |
H69A | 1.0900 | 0.4817 | −0.1150 | 0.090* | |
H69B | 0.8851 | 0.4516 | −0.1126 | 0.090* | |
H69C | 1.0262 | 0.3805 | −0.1364 | 0.090* | |
C70 | 1.2385 (3) | 0.34664 (19) | −0.05973 (8) | 0.0558 (6) | |
H70A | 1.2555 | 0.3062 | −0.0321 | 0.084* | |
H70B | 1.3130 | 0.4047 | −0.0573 | 0.084* | |
H70C | 1.2720 | 0.3098 | −0.0875 | 0.084* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0473 (12) | 0.0530 (12) | 0.0335 (9) | −0.0033 (10) | −0.0008 (8) | 0.0010 (9) |
C2 | 0.0496 (12) | 0.0528 (12) | 0.0335 (9) | 0.0067 (10) | 0.0027 (9) | 0.0050 (9) |
C3 | 0.0726 (16) | 0.0599 (13) | 0.0396 (10) | −0.0098 (13) | 0.0063 (11) | −0.0052 (10) |
C4 | 0.0705 (17) | 0.0733 (17) | 0.0499 (13) | −0.0224 (14) | 0.0036 (12) | −0.0090 (12) |
C5 | 0.0556 (14) | 0.0712 (15) | 0.0422 (11) | −0.0162 (12) | 0.0062 (10) | 0.0015 (10) |
C6 | 0.0487 (12) | 0.0498 (12) | 0.0308 (9) | 0.0016 (10) | 0.0007 (8) | 0.0053 (8) |
C20 | 0.0455 (12) | 0.0690 (15) | 0.0403 (10) | 0.0114 (11) | 0.0064 (10) | 0.0006 (10) |
P20 | 0.0344 (2) | 0.0479 (3) | 0.0368 (2) | −0.0008 (2) | 0.0011 (2) | −0.0072 (2) |
B20 | 0.0644 (19) | 0.0558 (17) | 0.0742 (19) | −0.0051 (14) | 0.0074 (15) | −0.0204 (15) |
C21 | 0.0358 (10) | 0.0539 (12) | 0.0366 (9) | −0.0056 (9) | 0.0049 (8) | −0.0021 (9) |
C22 | 0.0510 (14) | 0.0798 (18) | 0.0511 (13) | 0.0015 (12) | −0.0030 (11) | 0.0071 (12) |
C23 | 0.0578 (17) | 0.139 (3) | 0.0515 (14) | −0.0001 (19) | −0.0118 (13) | 0.0136 (17) |
C24 | 0.0517 (17) | 0.170 (4) | 0.0460 (13) | −0.025 (2) | −0.0011 (12) | −0.0158 (19) |
C25 | 0.0711 (19) | 0.103 (2) | 0.0631 (16) | −0.0409 (17) | 0.0220 (14) | −0.0383 (16) |
C26 | 0.0609 (14) | 0.0655 (14) | 0.0481 (11) | −0.0179 (13) | 0.0124 (12) | −0.0150 (11) |
C27 | 0.0352 (12) | 0.0746 (16) | 0.0574 (13) | −0.0025 (11) | 0.0030 (10) | −0.0075 (12) |
C28 | 0.0420 (15) | 0.119 (3) | 0.098 (2) | −0.0135 (16) | −0.0068 (16) | −0.021 (2) |
C29 | 0.0547 (17) | 0.108 (2) | 0.106 (2) | −0.0055 (16) | 0.0297 (17) | 0.030 (2) |
C30 | 0.0514 (16) | 0.099 (2) | 0.0735 (17) | 0.0125 (14) | 0.0160 (13) | −0.0121 (15) |
C60 | 0.0483 (12) | 0.0520 (12) | 0.0366 (10) | 0.0020 (10) | 0.0043 (8) | 0.0037 (9) |
P60 | 0.0349 (3) | 0.0499 (3) | 0.0347 (2) | 0.0011 (2) | 0.0021 (2) | −0.0002 (2) |
B60 | 0.0399 (15) | 0.093 (2) | 0.0583 (16) | 0.0019 (14) | 0.0024 (12) | −0.0090 (16) |
C61 | 0.0489 (12) | 0.0483 (12) | 0.0356 (9) | 0.0083 (10) | 0.0030 (8) | −0.0008 (9) |
C62 | 0.0614 (17) | 0.0651 (15) | 0.0680 (15) | 0.0198 (14) | 0.0039 (13) | 0.0121 (12) |
C63 | 0.116 (3) | 0.0548 (16) | 0.085 (2) | 0.0280 (18) | 0.023 (2) | 0.0211 (15) |
C64 | 0.117 (3) | 0.0529 (16) | 0.0760 (19) | −0.0072 (18) | 0.039 (2) | 0.0027 (14) |
C65 | 0.074 (2) | 0.0641 (16) | 0.0614 (15) | −0.0187 (15) | 0.0171 (14) | −0.0017 (13) |
C66 | 0.0503 (13) | 0.0546 (13) | 0.0448 (12) | −0.0052 (11) | 0.0044 (9) | 0.0022 (10) |
C67 | 0.0454 (12) | 0.0503 (12) | 0.0383 (10) | −0.0038 (10) | 0.0043 (9) | −0.0018 (9) |
C68 | 0.091 (2) | 0.0737 (18) | 0.0739 (18) | −0.0316 (17) | 0.0249 (16) | −0.0222 (15) |
C69 | 0.0649 (16) | 0.0774 (16) | 0.0370 (10) | 0.0094 (14) | −0.0066 (11) | −0.0060 (10) |
C70 | 0.0570 (15) | 0.0654 (15) | 0.0450 (12) | 0.0158 (12) | 0.0032 (10) | −0.0032 (11) |
C1—C2 | 1.385 (3) | C29—H29A | 0.9600 |
C1—C6 | 1.394 (3) | C29—H29B | 0.9600 |
C1—H1 | 0.9300 | C29—H29C | 0.9600 |
C2—C3 | 1.385 (3) | C30—H30A | 0.9600 |
C2—C20 | 1.510 (3) | C30—H30B | 0.9600 |
C3—C4 | 1.378 (3) | C30—H30C | 0.9600 |
C3—H3 | 0.9300 | C60—P60 | 1.829 (2) |
C4—C5 | 1.382 (3) | C60—H60A | 0.9700 |
C4—H4 | 0.9300 | C60—H60B | 0.9700 |
C5—C6 | 1.375 (3) | P60—C61 | 1.806 (2) |
C5—H5 | 0.9300 | P60—C67 | 1.862 (2) |
C6—C60 | 1.513 (3) | P60—B60 | 1.916 (3) |
C20—P20 | 1.824 (2) | B60—H60C | 0.9600 |
C20—H20A | 0.9700 | B60—H60D | 0.9600 |
C20—H20B | 0.9700 | B60—H60E | 0.9600 |
P20—C21 | 1.802 (2) | C61—C62 | 1.381 (3) |
P20—C27 | 1.858 (3) | C61—C66 | 1.394 (3) |
P20—B20 | 1.904 (3) | C62—C63 | 1.387 (4) |
B20—H20C | 0.9600 | C62—H62 | 0.9300 |
B20—H20D | 0.9600 | C63—C64 | 1.375 (5) |
B20—H20E | 0.9600 | C63—H63 | 0.9300 |
C21—C26 | 1.383 (3) | C64—C65 | 1.357 (4) |
C21—C22 | 1.384 (3) | C64—H64 | 0.9300 |
C22—C23 | 1.368 (3) | C65—C66 | 1.379 (3) |
C22—H22 | 0.9300 | C65—H65 | 0.9300 |
C23—C24 | 1.349 (5) | C66—H66 | 0.9300 |
C23—H23 | 0.9300 | C67—C70 | 1.524 (3) |
C24—C25 | 1.378 (5) | C67—C68 | 1.529 (3) |
C24—H24 | 0.9300 | C67—C69 | 1.534 (3) |
C25—C26 | 1.401 (3) | C68—H68A | 0.9600 |
C25—H25 | 0.9300 | C68—H68B | 0.9600 |
C26—H26 | 0.9300 | C68—H68C | 0.9600 |
C27—C30 | 1.520 (4) | C69—H69A | 0.9600 |
C27—C29 | 1.531 (4) | C69—H69B | 0.9600 |
C27—C28 | 1.540 (3) | C69—H69C | 0.9600 |
C28—H28A | 0.9600 | C70—H70A | 0.9600 |
C28—H28B | 0.9600 | C70—H70B | 0.9600 |
C28—H28C | 0.9600 | C70—H70C | 0.9600 |
C2—C1—C6 | 121.8 (2) | C27—C29—H29C | 109.5 |
C2—C1—H1 | 119.1 | H29A—C29—H29C | 109.5 |
C6—C1—H1 | 119.1 | H29B—C29—H29C | 109.5 |
C3—C2—C1 | 118.8 (2) | C27—C30—H30A | 109.5 |
C3—C2—C20 | 120.8 (2) | C27—C30—H30B | 109.5 |
C1—C2—C20 | 120.4 (2) | H30A—C30—H30B | 109.5 |
C4—C3—C2 | 119.7 (2) | C27—C30—H30C | 109.5 |
C4—C3—H3 | 120.1 | H30A—C30—H30C | 109.5 |
C2—C3—H3 | 120.1 | H30B—C30—H30C | 109.5 |
C3—C4—C5 | 120.9 (2) | C6—C60—P60 | 114.37 (15) |
C3—C4—H4 | 119.6 | C6—C60—H60A | 108.7 |
C5—C4—H4 | 119.6 | P60—C60—H60A | 108.7 |
C6—C5—C4 | 120.5 (2) | C6—C60—H60B | 108.7 |
C6—C5—H5 | 119.7 | P60—C60—H60B | 108.7 |
C4—C5—H5 | 119.7 | H60A—C60—H60B | 107.6 |
C5—C6—C1 | 118.2 (2) | C61—P60—C60 | 106.62 (11) |
C5—C6—C60 | 121.0 (2) | C61—P60—C67 | 105.07 (10) |
C1—C6—C60 | 120.8 (2) | C60—P60—C67 | 105.96 (10) |
C2—C20—P20 | 115.46 (16) | C61—P60—B60 | 113.24 (13) |
C2—C20—H20A | 108.4 | C60—P60—B60 | 112.13 (12) |
P20—C20—H20A | 108.4 | C67—P60—B60 | 113.20 (12) |
C2—C20—H20B | 108.4 | P60—B60—H60C | 109.5 |
P20—C20—H20B | 108.4 | P60—B60—H60D | 109.5 |
H20A—C20—H20B | 107.5 | H60C—B60—H60D | 109.5 |
C21—P20—C20 | 107.36 (11) | P60—B60—H60E | 109.5 |
C21—P20—C27 | 105.59 (11) | H60C—B60—H60E | 109.5 |
C20—P20—C27 | 105.53 (11) | H60D—B60—H60E | 109.5 |
C21—P20—B20 | 113.39 (13) | C62—C61—C66 | 117.9 (2) |
C20—P20—B20 | 111.91 (13) | C62—C61—P60 | 119.0 (2) |
C27—P20—B20 | 112.51 (13) | C66—C61—P60 | 122.92 (18) |
P20—B20—H20C | 109.5 | C61—C62—C63 | 120.5 (3) |
P20—B20—H20D | 109.5 | C61—C62—H62 | 119.7 |
H20C—B20—H20D | 109.5 | C63—C62—H62 | 119.7 |
P20—B20—H20E | 109.5 | C64—C63—C62 | 120.4 (3) |
H20C—B20—H20E | 109.5 | C64—C63—H63 | 119.8 |
H20D—B20—H20E | 109.5 | C62—C63—H63 | 119.8 |
C26—C21—C22 | 118.2 (2) | C65—C64—C63 | 119.7 (3) |
C26—C21—P20 | 124.57 (18) | C65—C64—H64 | 120.1 |
C22—C21—P20 | 117.13 (18) | C63—C64—H64 | 120.1 |
C23—C22—C21 | 121.7 (3) | C64—C65—C66 | 120.5 (3) |
C23—C22—H22 | 119.1 (2) | C64—C65—H65 | 119.7 |
C21—C22—H22 | 119.1 | C66—C65—H65 | 119.7 |
C24—C23—C22 | 120.0 (3) | C65—C66—C61 | 120.9 (2) |
C24—C23—H23 | 120.0 | C65—C66—H66 | 119.5 |
C22—C23—H23 | 120.0 | C61—C66—H66 | 119.5 |
C23—C24—C25 | 120.5 (3) | C70—C67—C68 | 109.1 (2) |
C23—C24—H24 | 119.8 | C70—C67—C69 | 109.33 (19) |
C25—C24—H24 | 119.8 | C68—C67—C69 | 109.4 (2) |
C24—C25—C26 | 119.8 (3) | C70—C67—P60 | 111.96 (16) |
C24—C25—H25 | 120.1 | C68—C67—P60 | 108.89 (16) |
C26—C25—H25 | 120.1 | C69—C67—P60 | 108.11 (15) |
C21—C26—C25 | 119.7 (3) | C67—C68—H68A | 109.5 |
C21—C26—H26 | 120.1 | C67—C68—H68B | 109.5 |
C25—C26—H26 | 120.1 | H68A—C68—H68B | 109.5 |
C30—C27—C29 | 109.6 (2) | C67—C68—H68C | 109.5 |
C30—C27—C28 | 109.8 (2) | H68A—C68—H68C | 109.5 |
C29—C27—C28 | 109.9 (2) | H68B—C68—H68C | 109.5 |
C30—C27—P20 | 111.56 (18) | C67—C69—H69A | 109.5 |
C29—C27—P20 | 108.05 (18) | C67—C69—H69B | 109.5 |
C28—C27—P20 | 107.87 (18) | H69A—C69—H69B | 109.5 |
C27—C28—H28A | 109.5 | C67—C69—H69C | 109.5 |
C27—C28—H28B | 109.5 | H69A—C69—H69C | 109.5 |
H28A—C28—H28B | 109.5 | H69B—C69—H69C | 109.5 |
C27—C28—H28C | 109.5 | C67—C70—H70A | 109.5 |
H28A—C28—H28C | 109.5 | C67—C70—H70B | 109.5 |
H28B—C28—H28C | 109.5 | H70A—C70—H70B | 109.5 |
C27—C29—H29A | 109.5 | C67—C70—H70C | 109.5 |
C27—C29—H29B | 109.5 | H70A—C70—H70C | 109.5 |
H29A—C29—H29B | 109.5 | H70B—C70—H70C | 109.5 |
C6—C1—C2—C3 | 0.7 (3) | C20—P20—C27—C29 | −170.04 (19) |
C6—C1—C2—C20 | 178.69 (19) | B20—P20—C27—C29 | 67.7 (2) |
C1—C2—C3—C4 | −0.1 (3) | C21—P20—C27—C28 | −175.3 (2) |
C20—C2—C3—C4 | −178.1 (2) | C20—P20—C27—C28 | 71.2 (2) |
C2—C3—C4—C5 | −0.1 (4) | B20—P20—C27—C28 | −51.1 (2) |
C3—C4—C5—C6 | −0.3 (4) | C5—C6—C60—P60 | −98.5 (2) |
C4—C5—C6—C1 | 0.9 (3) | C1—C6—C60—P60 | 81.7 (2) |
C4—C5—C6—C60 | −178.9 (2) | C6—C60—P60—C61 | 68.73 (18) |
C2—C1—C6—C5 | −1.1 (3) | C6—C60—P60—C67 | −179.69 (16) |
C2—C1—C6—C60 | 178.67 (19) | C6—C60—P60—B60 | −55.7 (2) |
C3—C2—C20—P20 | −98.5 (2) | C60—P60—C61—C62 | −149.02 (18) |
C1—C2—C20—P20 | 83.5 (2) | C67—P60—C61—C62 | 98.79 (19) |
C2—C20—P20—C21 | 75.01 (19) | B60—P60—C61—C62 | −25.2 (2) |
C2—C20—P20—C27 | −172.72 (17) | C60—P60—C61—C66 | 35.7 (2) |
C2—C20—P20—B20 | −50.0 (2) | C67—P60—C61—C66 | −76.5 (2) |
C20—P20—C21—C26 | 28.0 (2) | B60—P60—C61—C66 | 159.51 (18) |
C27—P20—C21—C26 | −84.3 (2) | C66—C61—C62—C63 | 0.6 (4) |
B20—P20—C21—C26 | 152.1 (2) | P60—C61—C62—C63 | −174.9 (2) |
C20—P20—C21—C22 | −155.19 (17) | C61—C62—C63—C64 | −0.4 (4) |
C27—P20—C21—C22 | 92.6 (2) | C62—C63—C64—C65 | −0.1 (5) |
B20—P20—C21—C22 | −31.0 (2) | C63—C64—C65—C66 | 0.4 (4) |
C26—C21—C22—C23 | 1.8 (3) | C64—C65—C66—C61 | −0.3 (4) |
P20—C21—C22—C23 | −175.3 (2) | C62—C61—C66—C65 | −0.2 (3) |
C21—C22—C23—C24 | −1.5 (4) | P60—C61—C66—C65 | 175.05 (17) |
C22—C23—C24—C25 | −0.7 (5) | C61—P60—C67—C70 | 72.15 (18) |
C23—C24—C25—C26 | 2.5 (4) | C60—P60—C67—C70 | −40.51 (19) |
C22—C21—C26—C25 | 0.1 (3) | B60—P60—C67—C70 | −163.80 (18) |
P20—C21—C26—C25 | 176.87 (17) | C61—P60—C67—C68 | −167.13 (19) |
C24—C25—C26—C21 | −2.2 (4) | C60—P60—C67—C68 | 80.2 (2) |
C21—P20—C27—C30 | 64.0 (2) | B60—P60—C67—C68 | −43.1 (2) |
C20—P20—C27—C30 | −49.5 (2) | C61—P60—C67—C69 | −48.34 (19) |
B20—P20—C27—C30 | −171.8 (2) | C60—P60—C67—C69 | −160.99 (16) |
C21—P20—C27—C29 | −56.5 (2) | B60—P60—C67—C69 | 75.7 (2) |
Experimental details
Crystal data | |
Chemical formula | C28H42B2P2 |
Mr | 462.18 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 293 |
a, b, c (Å) | 7.380 (6), 13.515 (6), 28.189 (14) |
V (Å3) | 2812 (3) |
Z | 4 |
Radiation type | Cu Kα |
µ (mm−1) | 1.48 |
Crystal size (mm) | 0.83 × 0.22 × 0.14 |
Data collection | |
Diffractometer | Nonius CAD-4 diffractometer |
Absorption correction | Integration (ABSORP in NRCVAX; Gabe et al., 1989) |
Tmin, Tmax | 0.539, 0.830 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 30802, 5320, 4737 |
Rint | 0.062 |
(sin θ/λ)max (Å−1) | 0.609 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.035, 0.088, 0.98 |
No. of reflections | 5320 |
No. of parameters | 298 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.21, −0.22 |
Absolute structure | Flack (1983), 2274 Friedel pairs |
Absolute structure parameter | −0.004 (18) |
Computer programs: CAD-4 Software (Enraf-Nonius, 1989), CAD-4 Software, NRC-2 and NRC-2A (Ahmed et al., 1973), SHELXS97 (Sheldrick, 1997), SHELXL96 (Sheldrick, 1996), SHELXTL (Bruker, 1997), SHELXL96.
C20—P20 | 1.824 (2) | C60—P60 | 1.829 (2) |
P20—C21 | 1.802 (2) | P60—C61 | 1.806 (2) |
P20—C27 | 1.858 (3) | P60—C67 | 1.862 (2) |
P20—B20 | 1.904 (3) | P60—B60 | 1.916 (3) |
C21—P20—C20 | 107.36 (11) | C61—P60—C60 | 106.62 (11) |
C21—P20—C27 | 105.59 (11) | C61—P60—C67 | 105.07 (10) |
C20—P20—C27 | 105.53 (11) | C60—P60—C67 | 105.96 (10) |
C21—P20—B20 | 113.39 (13) | C61—P60—B60 | 113.24 (13) |
C20—P20—B20 | 111.91 (13) | C60—P60—B60 | 112.13 (12) |
C27—P20—B20 | 112.51 (13) | C67—P60—B60 | 113.20 (12) |
The importance of phosphine ligands in transition metal chemistry is remarkable. Among them optically active C2-symmetric phosphine ligands proved to be instrumental in asymmetric catalysis (Yamanoi & Imamoto, 1999). Recently, P-chiral phosphines have emerged as a good chiral controller in transition metal-catalyzed reaction (Kolodiazhnyi, 1998). Transition metal complexes with phosphorus–carbon–phosphorus (PCP) tridentate or pincer ligands were studied extensively (Laurenti & Santelli, 1999). However, to our knowledge, no structure of a pincer ligand with P-chiral phosphines has been reported so far. Therefore, we wish to report the first crystallographic structure of a P-chiral PCP tridentate ligand as a bis-boron complex.
Fig. 1 clearly indicates the C2-symmetry of (II). The two phosphorus substituents are on opposite sides of the aromatic ring. Both P atoms have adopted a distorted tetrahedral geometry. The average B—P—C angle and P—B distance are 112.7 (6)° and 1.910 (6) Å, respectively (Table 1).