10.1002/cplu.202000239
ChemPlusChem
FULL PAPER
overlapping with the residual C6D6 signals.), 132.2 (d, 3JCP = 10.6 Hz, Mes
+ PMes p-CH3), 21.1 (d, 5JCP = 1.1 Hz, fused Mes p-C2H3), 25.5 (d, 3JCP
=
1
1
m-C), 144.75 (d, JCP = 9.1 Hz, Mes ipso-C), 159.7 (d, JCP = 102.7 Hz,
6.0 Hz, PMes o-C8H3), 25.7 (d, 3JCP = 24.2 Hz, AlC-CH2CH3), 27.3 (d, 3JCP
= 3.0 Hz, PMes o-C6H3), 29.5 (s, activated C1H3), 32.1 (AlC(CUH3)3), 33.0
(AlC(CLH3)3), 51.6 (s, CO2CH3), 52.9 (d, 4JCP =1.2 Hz, OCH3), 56.7 (d, 2JCP
= 15.1 Hz, C4(CH3)CO2Me), 74.8 (d, 1JCP = 114.8 Hz, PC5-C(CH3)CO2Me),
120.2 (d, 1JCP = 80.0 Hz, PMes ipso-CMi), 123.2 (d, 1JCP = 81.5 Hz, fused
2
PCO2), 199.7 (d, JCP = 33.2 Hz, CP=CAl) ppm. 27Al{1H} NMR (156 MHz,
C6D6, 298 K): δ = 145.7 ppm. 31P{1H} NMR (243 MHz, C6D6, 298 K): δ = –
12.9 ppm. The NMR spectra for pure 8Et could not be obtained due to the
decomposition and easy dissociation of CO2.
3
Mes ispo-CFi), 123.7 (d, JCP = 9.1 Hz, fused Mes m-CFUm), 132.3-132.4
(two doublets, PMes m-CMUm + fused Mes m-CFLm), 133.3 (PMes m-CMLm),
Reactions of 3Ph with DMAD
1
2
140.0 (d, JCP = 84.6 Hz, CAl=CP), 140.4 (d, JCP = 9.1 Hz, fused Mes o-
CFLo), 142.6 (d, 4JCP = 3.0 Hz, PMes p-CMp), 144.1 (d, 4JCP = 2.3 Hz, fused
In a J. Young NMR tube, a mixture of 3Ph (14.5 mg, 0.0246 mmol) and
DMAD (10.2 mg, 0.0718 mmol, 2.9 eq.) in C6D6 (0.6 mL) was heated to 70
ºC for 20 h. The formation of 9Ph in 87% yield was estimated as judged
by 31P{1H} NMR spectroscopy. After all volatiles were removed under
reduced pressure at room temperature, the residue was washed with
hexane to afford 9Ph as a red solid (4.1 mg, 0.0056 mmol, 23%). Single
crystals of 9Ph suitable for X-ray crystallographic analysis were obtained
from recrystallization in benzene. 9Ph: A pink solid, mp. 131 ºC (dec.). 1H
NMR (600 MHz, C6D6, 298 K): δ = 0.98 (s, 9H, AlC(CHU3), 1.24 (s, 3H,
fused Mes o-CHG3), 1.33 (s, 9H, AlC(CHL3)), 1.87 (s, 3H, fused Mes p-
CHI3), 1.92 (s, 3H, PMes p-CHF3), 2.36 (s, 3H, activated Mes CHE3), 2.63
(s, 3H, PMes o-CHJ3), 3.05 (s, 3H, PMes o-CHH3), 3.53 (s, 3H, CO2CH3),
3.66 (s, 3H, OCH3), 6.25 (m, 1H, fused m-HB), 6.40 (d, 1H, 3JHH = 7.2 Hz,
Ph), 6.59 (t, 1H, 3JHH = 6.9 Hz, Ph), 6.64 (br. s, 1H, PMes m-HD), 6.69-6.73
Mes p-C2), 145.8 (d, JCP = 12.1 Hz, PMes o-CMLo), 146.1 (d, JCP = 9.1
3
3
Hz, PMes o-CMUo), 155.2 (d, 2JCP = 21.1 Hz, fused Mes o-CFUo), 168.2 (d,
2JCP = 18.1 Hz, C-OMe), 174.6 (d, JCP = 7.6 Hz, CO2Me), 188.2 (br. d,
3
2JCP = 33.2 Hz, CAl=CP) ppm. 31P{1H} NMR (243 MHz, C6D6, 298 K): δ =
15.9 ppm. No 27Al{1H} NMR signal was observed even after long-time
measurement (number of scans: 8880 times). See Figures S23 and S24
for details of the NMR assignments of 9Et. Due to the extremely high air-
and moisture-sensitivity, satisfactory data of elemental analysis and mass
spectrometry could not be obtained.
X-Ray crystallographic analysis
(m, 3H, Ph), 6.80 (d, 1H, 4JHP = 53.6 Hz, PMes m-HC), 6.82 (d, 1H, 3JHH
=
The intensity data were collected on a Saturn 70 CCD diffractometer with
a VariMax Mo optic system using Mo Kα radiation (λ = 0.71073 Å) (for 3Ph,
7.2 Hz, Ph), 6.88 (t, 1H, 3JHH = 7.2 Hz, Ph), 7.02-7.06 (m, 3H, Ph), 7.19 (s,
1H, fused m-HA) ppm. 13C{1H} NMR (151 MHz, C6D6, 298 K): δ = 17.0 (br.
7Et, and 9Et),
a
Mercury CCD diffractometer with graphite
3
s, AlCLMe3), 17.4 (br. s, AlCUMe3), 19.6 (d, JCP = 3.0 Hz, fused Mes o-
monochromated Mo Kα radiation (λ = 0.71069 Å) [for 3Et, 7Ph, and
4Ph·0.5(PhCCPh)], and the BL02B1 beamline of Spring-8 (2019B1774B
C3H3), 20.6 (d, 5JCP = 1.5 Hz, PMes p-C7H3), 21.3 (d, 5JCP = 1.5 Hz, fused
Mes p-C2H3), 25.9 (d, 3JCP = 6.0 Hz, PMes o-C6H3), 29.5 (d, 3JCP = 3.0 Hz,
PMes o-C8H3), 30.2 (s, activated C1H3), 31.6 (s, AlC(CUH3)3), 32.8 (s,
and 2019B1578B) on
a large cylindrical camera using synchrotron
radiation (λ = 0.4119 Å) (for 9Ph). All frame images (Dectris) were
converted to the SFRM format using Henkankun-R.[35] Data reduction was
performed using Bruker SAINT (for 9Ph). An empirical absorption
correction was applied to the diffraction data using ABSPACK[36] [for 3Ph,
3Et, 4Ph·0.5(PhCCPh), 7Ph, 7Et, and 9Et]. The structure was solved by
a direct method (SHELXT)[37] and refined by a full-matrix least-squares
method on F2 for all reflections (SHELXL-2016/4 or 2018/1).[38] All
hydrogen atoms were placed using AFIX instructions, while all other atoms
were refined anisotropically. CCDC-1970130 (3Ph), CCDC-1970132 (3Et),
CCDC-1970131 [4Ph·0.5(PhCCPh)], CCDC-1970129 (7Ph), CCDC-
1970134 (7Et), CCDC-1970128 (9Ph) and CCDC-1970133 (9Et) contain
the supplementary crystallographic data.
2
AlC(CLH3)3), 51.8 (s, CO2CH3), 53.1 (s, OCH3), 57.2 (d, JCP = 15.1 Hz,
C4(CH3)CO2Me), 75.1 (d, 1JCP = 114.8 Hz, PC5-C(CH3)CO2Me), 119.4 (d,
3
1JCP = 78.5 Hz, PMes ipso-CMi), 123.4 (d, JCP = 9.1 Hz, fused Mes m-
CFUm), 124.2 (d, 1JCP = 84.6 Hz, fused Mes ipso-CFi), 125.3 (s, Ph), 126.2
(s, Ph), 126.6 (s, Ph), 127.0 (s, Ph), 128.1 (s, Ph), 130.6 (s, Ph), 131.7 (d,
3
3JCP = 10.8 Hz, fused Mes m-CFLm), 132.9 (d, JCP = 10.8 Hz, PMes m-
3
CMLm), 133.3 (d, JCP = 12.1 Hz, PMes m-CMUm), 134.0 (d, JCP = 6.0 Hz,
2
1
Ph), 137.5 (d, JCP = 21.1 Hz, PhP-ipso-C), 139.8 (d, JCP = 87.6 Hz,
CAl=CP), 142.3 (d, JCP = 7.6 Hz, fused Mes o-CFlo), 143.1 (d, JCP = 3.0
Hz, PMes p-CMp), 144.8 (d, 4JCP = 3.0 Hz, fused Mes p-CFp), 146.1 (d, 2JCP
= 13.6 Hz, PMes o-CMUo), 146.7 (d, 2JCP = 10.6 Hz, PMes o-CMLo), 148.9
(d, JCP = 30.2 Hz, PhAl-ipso-C), 154.6 (d, JCP =21.1 Hz, fused Mes o-
CFUo), 168.1 (d, 2JCP = 16.6 Hz, H3CO-C), 174.5 (d, 3JCP = 9.1 Hz, CO2CH3),
191.7 (d, 2JCP = 37.8 Hz, CAl=CP) ppm. 31P{1H} NMR (243 MHz, C6D6, 298
K): δ = 18.7 ppm. No 27Al NMR signal was observed even after long-time
measurement (number of scans: 2048 times). See Figures S19 and S20
for details of NMR assignments of 9Ph. Anal. Calcd for C46H56AlO4P: C,
75.59 H, 7.72. Found: C, 75.30; H, 7.86.
2
4
3
2
Computational details
All calculations were performed using the Gaussian 16 (Rev. B. 01 or Rev.
C. 01)[39] program package with B3LYP functional[40] including Grimme
dispersion correction (D3)[41] along with combined basis sets: 6-31G(d)
level. All the geometry optimizations have been performed until the
residual mean force is smaller than 1.0×10−5 a.u. (tight threshold in
Gaussian). The frequency calculations were carried out for each optimized
structure to confirm the absence of any imaginary frequencies. Similarly,
hessians, calculated for the transition states, were confirmed to have one
imaginary frequency corresponding to the reaction coordinates. The
reaction pathways for the structures of transition states were investigated
and confirmed by intrinsic reaction coordinate (IRC) calculations. Natural
bond orbital (NBO) analysis have been carried out with the NBO 6.0
program package,[42] linked to single-point calculations using Gaussian 16.
Reactions of 3Et with DMAD
In a J. Young NMR tube, a solution of 3Et (11.2 mg, 0.0227 mmol) in C6H6
(0.6 mL) was treated with DMAD (4.0 mg, 0.0.281 mmol, 1.2 eq.). The
reaction was monitored by NMR spectroscopy, suggesting the quantitative
formation of 9Et. After all volatiles were removed under reduced pressure
at room temperature, the residue was recrystallization from benzene to
afford 9Et as a red solid (7.2 mg, 0.011 mmol, 50%). 9Et: A red solid, mp.
107 ºC (dec.). 1H NMR (600 MHz, C6D6, 298 K): δ = 0.59 (t, 3H, 3JHH = 7.2
Hz, AlC-CH2CH3), 1.14 (s, 9H, AlC(CHU3)3), 1.27 (td, 3H, 3JHH = 7.5 Hz, 4JHP
= 0.6 Hz, PC-CH2CH3), 1.40 (s, 9H, AlC(CHL3)3, 1.85 (s, 3H, fused-Mes p-
CHF3), 1.92 (s with m, 3H+1H, PMes p-CH3+AlC-CHCH3), 1.98 (s, 3H,
fused Mes o-CHG3), 2.10 (s, 3H, activated CHE3), 2.56 (s, 6H, PMes o-
CH3), 2.65-2.93 (m, 2H+1H, PC-CH2CH3+AlC-CHCH3), 3.42 (s, 3H
CO2CH3), 3.60 (s, 3H, OCH3), 6.46 (dm, 1H, 4JHP = 3.6 Hz, fused Mes m-
HB), 6.61 (br. s, 1H, PMes m-HD), 6.69 (dm, 1H, 4JHP = 5.4 Hz, PMes m-
HC), 7.09 (s, 1H, fused m-HA) ppm. 13C{1H} NMR (151 MHz, C6D6, 298 K):
δ = 12.9 (d, 3JCP = 3.0 Hz, PC-CH2CH3), 16.2 (br. s, AlCUMe3), 16.3 (s, AlC-
CH2CH3), 16.9 (br. s, AlCLMe3), 20.5-20.6 (two doublets, fused Mes o-CH3
Acknowledgements
This work was supported by KAKENHI (JP24109013,
JP26620028, JP19H05528, JP18H01963, and JP19H05635),
Integrated Research Consortium on Chemical Science (IRCCS).
T. Y. gratefully acknowledges a Research Fellowship for Young
8
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