Carbonyl Hydrosilylation by a Silyl Hydride Complex
FULL PAPER
formation of a white precipitate of LiCl was observed. The mixture was
filtered, all of the volatile compounds were removed by evaporation, and
the residue was extracted with hexanes (50 mL). The solution was con-
centrated to about 10 mL and the product was crystallized at ꢀ308C
overnight to give complex 3 as a fine yellow solid (109.7 mg, 87% yield).
(121.5 MHz, C6D6): d=10.8 (t, 2J
(d, 2J(P,P)=24.3 Hz, 2P; 2PMe3); 13C{1H} NMR (75.5 MHz, C6D6): d=
146.1 (s; i-C, NAr), 124.9 (s; o-C, NAr), 123.6 (s; m-C, NAr), 123.0 (s; p-
G
AHCTUNGTRENNUNG
23.4 Hz;, PMe3), 24.9 (s; CH3, NAr), 23.0 (vt, 1J
G
1
19.7 ppm (s; CH3, Si
G
H
29Si HSQC NMR (f1=600 MHz, f2=
1H NMR (600 MHz, C6D6): d=ꢀ3.92 (dt, 2J
G
ACHTUNGTRNE(NUNG P,H)=
ꢀ
119.2 MHz, J=7 Hz, C6D6, 29Si projection): d=25.6 ppm (Si
(OEt)3).
65.4 Hz, 1H; MoH), 1.17 (br s, 18H; 2PMe3), 1.21 (d, 2J
ACHTUNGTRENNUNG
9H; PMe3), 1.31 (d, 3J
ACHTUNGTRENNUNG
(H,H)=6.6 Hz, 12H; 4CH3, ArN), 4.39 (sept, 3J-
Complex 11: 1H NMR (300 MHz, C6D6): d=6.86–7.04 (m, 3H; m-H and
p-H, NAr), 4.00 (m, 6H; 2CH, NAr and 2CH2, Mo
(OEt)2), 1.39 (vt, 2J-
(H,P)=7.2 Hz, 18H; 2PMe3), 1.27 (d, 2J
(H,P)=7.8 Hz, 9H; PMe3), 1.21
3
A
AHCTUNGTRENNUNG
3
147.0 Hz, 2H; SiH2), 7.01 (d, J
3J
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
(t, 3J (OEt)2), 1.14 ppm (d, 3J
ACHTUNGTREN(NNGU H,H)=6.9 Hz, 6H; 2CH3, MoACHTUNREGTNNUNG ACHTUNGTRENNUNG(H,H)=
A
ACHTUNGTRENNUNG
6.9 Hz, 12H; 4CH3, NAr); 31P{1H} NMR (121.5 MHz, C6D6): d=2.6 (t, 2J-
A
ACHTUNGTRENNUNG
2
(P,P)=34.0 Hz, 1P; PMe3), ꢀ8.84 ppm (d, J
ACHTUNGTREN(UNGN P,P)=34.0 Hz, 2P; 2PMe3);
13C{1H} NMR (75.5 MHz, C6D6): d=147.2 (s; i-C, NAr), 132.6 (s; o-C,
NAr), 123.4 (s; m-C, NAr), 119.2 (s; p-C, NAr), 59.6 (s; CH2, Mo(OEt)2),
27.5 (s; CH, NAr), 25.8 (s; CH3, Mo (C,P)=24.9 Hz;
(OEt)2), 23.4 (d, 1J
PMe3), 22.9 (s; CH3, NAr), 17.4 ppm (vt, J(C,P)=22.6 Hz; PMe3).
Preparation of [(ArN=)Mo(H)(SiHMePh)(PMe3)3] (10): A 1.6m solution
A
ACHTUNGTRENNUNG
PMe3), 26.4 (s; 2CH, ArN), 122.9 (s; p-C, ArN), 123.3 (s; m-C, ArN),
126.7 (s; p-C, PhSi), 127.1 (s; m-C, PhSi), 132.0 (s; i-C, PhSi), 136.6 (s; o-
C, PhSi), 145.4 (s; o-C, ArN), 146.6 ppm (s; i-C, ArN); 31P{1H} NMR
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
1
AHCTUNGTRENNUNG
(243 MHz, C6D6): d=ꢀ1.9 (d, 2J
(P,P)=23.8 Hz; 2PMe3), 10.0 ppm (t, 2J-
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
ACHTUNGTRENNUNG
(P,P)=23.8 Hz; PMe3); 31P NMR (selectively decoupled from methyl
of nBuLi in hexanes (0.33 mmol) was added to a mixture of PhMeSiH2
(67.0 mL, 0.49 mmol) and complex 1 (174.0 mg, 0.33 mmol) in benzene
(10 mL) at RT. The mixture was stirred at ambient temperature for
30 min. The formation of a white precipitate of LiCl was observed. All of
the volatile compounds were removed by evaporation and the residue
was extracted with hexanes (15 mL). The solvent was removed under re-
duced pressure to give a dark-brown oil. Recrystallization from hexanes
at ꢀ808C yielded complex 10 as a dark-brown solid. Yield: 15.6 mg, 8%.
The product was formed as a mixture of isomers, owing to chirality at the
2
groups, 243 MHz, C6D6): d=ꢀ1.9 (br m; 2PMe3), 10.0 ppm (dt, J
ACHTUNGTRENNUNG
65.5 Hz, 2J
ACHTUNGTRENNUNG
0.2 ppm (td, 2J(Si,P)=9.6 Hz, 2J
ACHTUNGTRENNUNG ACHTUGNTREN(NUNG Si,P)=21.7 Hz; SiH2Ph); IR (nujol): n˜ =
ꢀ1
ꢀ
ꢀ
1699 (s; Mo H), 1998 cm (s; Si H); elemental analysis calcd (%)for
C27H52MoNP3Si (607.655): C 53.37, H 8.63, N 2.31; found: C 53.76,
H 8.53, N 2.21.
Preparation of [(Ar’N=)Mo(H)ACTHNUTRGENNUG(SiH2Ph)AHCTUNGTERN(NUGN PMe3)3] (8): PhSiH3 (58.8 mL,
0.476 mmol) and PMe3 (150.0 mL, 1.428 mmol) were added in one portion
to a solution of complex 4 (189.0 mg, 0.476 mmol) in toluene (50 mL) at
RT. No visual change in the mixture was observed and the mixture was
stirred at RT for 2 weeks. All of the volatile compounds were removed
by evaporation and the residue was dried under vacuum and extracted
with Et2O (30 mL). Then, the solution was concentrated to 5 mL, an
equal amount of hexanes was added, and the mixture was left to stand at
ꢀ308C, overnight, to give complex 8 a fine yellow powder, which was
dried under vacuum. Yield: 125.5 mg, 48%; 1H NMR (600 MHz, C6D6):
silicon center. 1H NMR (300 MHz, C6D6): d=7.93 (d, 3J
2H; o-H, SiPh), 7.30 (t, 3J
(H,H)=7.2 Hz, 2H), 6.98–7.20 (m, 4H), 5.78
(br m, 1H; SiH), 4.27 (sept, 3J
(H,H)=6.9 Hz, 2H; 2CH, NAr), 1.27 (m,
3J(H,H)=6.9 Hz, 2J
(H,P)=6.3 Hz, 21H; 12H from 4CH3, NAr and 9H
from PMe3), 1.21 (d, 2J(H,P)=6.6 Hz, 9H; PMe3), 1.14 (d, 3J
(H,H)=
4.5 Hz, 3H; SiMe), 1.04 (d, 2J
(H,P)=6.0 Hz, 9H; PMe3), ꢀ3.38 ppm (dt,
2J(H,P)=68.1 Hz and 20.1 Hz; MoH); 13C{1H} NMR (75.5 MHz, C6D6):
d=21.8 (d, 1J(C,P)=19.6 Hz; PMe3), 23.1 (d, 1J
(C,P)=15.8 Hz; PMe3),
24.80 (s; 4CH3, NAr), 24.83 (s; 4CH3, NAr), 26.65 (d, 1J
(C,P)=23.4 Hz;
PMe3), 26.73 (d, 1J
(C,P)=21.9 Hz; PMe3), 27.3 (s; 2CH, NAr), 123.9 (s;
ACHTUNGTREN(NUNG H,H)=6.9 Hz,
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
A
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
A
ACHTUNGTRENNUNG
d=ꢀ3.56 (dt, 2J
ACHTUNGTRENNUNG ACHTUNGTRENNUNG
(P,H)=18.5 Hz, 2J
AHCTUNGTRENNUNG
2J(H,P)=6.5 Hz, 18H; 2PMe3), 1.20 (d, 2J
ACHTUNGTRENNUNG ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
3
3
2.49 (s, 6H; 2CH3, Ar’N), 5.83 (t, J
(H,H)=7.5 Hz, 1H; p-H, Ar’N), 6.95 (d, 3J
Ar’N), 7.18 (t, 3J(H,H)=7.5 Hz, 1H; p-H, PhSi), 7.28 (t, 3J
7.5 Hz, 2H; m-H, PhSi), 8.09 ppm (d, 3J
(H,H)=7.5 Hz, 2H; o-H, PhSi);
13C{1H} NMR (75.5 MHz, C6D6): d=20.9 (s; CH3, Ar’N), 21.6 (vt, 1J-
(C,P)=21.9 Hz; PMe3), 25.6 (d, 1J
(C,P)=21.9 Hz; PMe3), 123.6 (s; p-C,
ACHTUNGTRENNUNG
m-C, NAr), 124.9 (s; p-C, NAr), 126.8 (s; p-C, SiPh), 127.5 (s; m-C,
SiPh), 129.9 (s; i-C, SiPh), 135.0 (s; o-C, NAr), 136.1 (s; o-C, SiPh),
145.3 ppm (s; i-C, NAr); 31P{1H} NMR (121.5 MHz, C6D6): d=ꢀ2.6 (qd,
G
ACHTUNGTRENNUNG
G
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
2J
2J
ACHTUNGTREN(NNUG P,P)=29.2 Hz, 23.1 Hz, 21.9 Hz, 23.1 Hz, 2P; 2PMe3), 11.9 ppm (dd,
AHCTUNGTRENNUNG
(P,P)=23.1 Hz and 21.9 Hz, 1P; PMe3); 29Si INEPT+ NMR (59.6 MHz,
C
ACHTUNGTRENNUNG
1
J=200 Hz, C6D6): d=13.0 ppm (d, J
ACHTUNGTNER(NUNG Si,H)=143.1 Hz; SiHMePh).
Ar’N), 126.9 (s; p-C, PhSi), 127.1 (s; m-C, Ar’N), 128.3 (s; m-C, PhSi),
135.3 (s; o-C, Ar’N), 136.8 (s; o-C, PhSi), 148.7 (s; i-C, PhSi), 156.4 ppm
Reaction of [(ArN=)Mo(H)(Cl)(PMe3)3] (1) with LiBH4: A 2.0m solu-
AHCTUNGTRENNUNG
(s; i-C, Ar’N); 31P{1H} NMR (121.5 MHz, C6D6): d=ꢀ1.5 (d, 2J
ACHTUNGTRNE(NUNG P,P)=
tion of LiBH4 in THF (0.10 mL, 0.09 mmol; Important: BH3 should not
be present!) was added in one portion to a solution of complex 1
(50.0 mg, 0.09 mmol) in Et2O (10 mL) at RT. The reaction mixture was
stirred at RT for 45 min. NMR analysis showed the formation of a mix-
ACTHNUTRGNEUNG
23.1 Hz; 2PMe3), 10.5 ppm (t, 2J(P,P)=23.1 Hz; PMe3). 29Si INEPT+
NMR (59.6 MHz, J=200 Hz, C6D6): d=1.7 ppm (t, 1J
G
ꢀ1
ꢀ
ꢀ
SiH2Ph); IR (nujol): n˜ =1647 (s; Mo H), 2152 cm (s; Si H); elemental
analysis calcd (%)for C23H44MoNP3Si (551.549): C 50.09, H 8.04, N 2.54;
found: C 50.54, H 7.98, N 2.73.
ture of [(ArN=)Mo(H)ACHTNUGRTENNUG ACHTUNTGREN(NUGN PMe3)2] (6, highly fluxional at RT) and
(h2-BH4)
unidentified decomposition products. All attempts to isolate complex 6 in
its analytically pure form were unsuccessful. The addition of BH3·THF to
complex 6 gave complex 5. 1H NMR (300 MHz, C6D6): d=7.02 (t, 3J-
(h2-BH4)
Reaction of [(ArN=)MoACHTGNURTNENGUN 2ACHUTNTRGEG(NNNU PMe3)2] (5) with HSiACHTNUGRTEN(NUGN OEt)3:
(EtO)3SiH (0.24 mL, 1.28 mmol) and PMe3 (0.33 mL, 3.21 mmol) were
added in one portion to a solution of complex 5 (0.15 g, 0.32 mmol) in
Et2O (20 mL) at RT. The reaction mixture was stirred at RT for 5 days.
All of the volatile compounds were removed by evaporation to give
ACHUTNGREUNNG ACHTUNGTRNE(NUGN H,H)=7.8 Hz, 2H; m-H,
(H,H)=7.8 Hz, 1H; p-H, NAr), 6.89 (d, 3J
NAr), 4.41 (sept, 3J(H,H)=6.9 Hz, 2H; 2CH, NAr), 1.18 (d, 3J
ACTHNUTRGENNUG ACHTUNGTRENNUNG(H,H)=
6.9 Hz, 12H; 4CH3, NAr), 0.90 ppm (br s, 18H; 2PMe3); 31P{1H} NMR
(121.5 MHz, C6D6): d=3.3 ppm (s; PMe3).
[(ArN=)Mo(H)(Si
under vacuum. Yield: 72.2 mg, 34%. The product was unstable at RT in
solution and slowly (1 week) decomposed to form [(ArN=)Mo(OEt)2-
(PMe3)3] (11) and a mixture of unknown products. All attempts to isolate
ACHTUNGTRENNUNG(OEt)3)ACHTUNGTRNE(NUGN PMe3)3] (9) as a brown oil, which was dried
NMR-scale reaction of complex
3 with PhSiD3: PhSiD3 (2.1 mL,
AHCTUNGTRENNUNG
0.017 mmol) was added in one portion to a solution of complex 3
(10.3 mg, 0.017 mmol) and TMS (1.0 mL, 0.007 mmol) in C6D6 (0.6 mL) at
RT in an NMR tube. The reaction mixture was left to stand at RT for
10 min. NMR analysis showed deuterium scrambling at the silyl and hy-
dride positions: 59% and 65% H/D exchange were observed for the hy-
dride and silyl positions of complex 3, respectively. The percentage of in-
corporated D was calculated by integration of the residual H resonances
for the hydride and silyl substituents on the complex before and after the
addition of PhSiD3. In both cases, all of the integrals were normalized to
the integral for TMS.
ACHTUNGTRENNUNG
compound 7 in its analytically pure form failed, owing to its decomposi-
tion.
Complex 9: 1H NMR (300 MHz, C6D6): d=ꢀ4.73 (dt, 2J
ACHTUNGTREN(NUNG P,H)=18.6 Hz,
2J
(d, 3J
3CH3, Si
(H,H)=6.9 Hz, 6H; 3CH2, Si
2CH, NAr), 6.95–6.97 ppm (m, 3H; m-H and p-H, NAr); 31P{1H} NMR
ACHTUNGTRENNUNG ACHTUGNTRENN(UGN H,P)=6.6 Hz, 9H; PMe3), 1.31
(P,H)=62.1 Hz, 1H; MoH), 1.20 (d, 2J
A
ACHTUNGTREN(NGNU H,H)=6.9 Hz, 9H;
A
ACHTUNGTRENNUNG
A
R
ACHTUNGTRENNUNG
Chem. Eur. J. 2013, 00, 0 – 0
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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