Organometallics
Article
1
162 MHz, ppm): δ 54.3. HRMS (ESI, m/z): [M − H]− calcd for
C38H35N4O6P2, 705.2037; found, 705.2040 (Δ = 0.4 ppm).
amounts of other phosphorus compounds in the 31P NMR. H NMR
(CDCl3, 400 MHz, ppm): δ 7.40−7.27 (m, 12H), 7.17 (app. d, J = 7.5
Hz, 4H), 7.02 (app. d, J = 7.5 Hz, 4H), 5.59 (vdd, 2H), 5.49 (bs, 2H),
3.10−2.89 (m, 2H), 2.83−2.70 (m, 6H), 0.99 (AA′BB′XX′, 2H), 0.49
(AA′BB′XX′, 2H). 31P{1H} NMR (CDCl3, 162 MHz, ppm): δ 6.5.
13C{1H} NMR (CDCl3, 126 MHz, ppm): δ 140.3 (vt, 1JC−P = 7.0 Hz),
TNSB BDP (7). 7 was purified via column chromatography
(EtOAc/DCM = 1:9, Rf = 0.38). Colorless needles were obtained
by gas-phase diffusion of pentane into a CH2Cl2 solution of 7. 234.2
mg, 20% yield, contains solvents in the crystal lattice. 1H NMR
3
2
2
(CDCl3, 400 MHz, ppm): δ 8.25 (d, JH−H = 8.4 Hz, 2H), 7.96 (app.
134.5 (vt, JC−P = 1.7 Hz), 127.5, 127.4 (vt, JC−P = 3.7 Hz), 127.3,
127.2, 126.1 (bs), 125.9, 125.3, 74.6 (vdd), 68.7 (vdd), 54.6, 54.5, 23.4,
23.1, 19.0 (d, 1JC−P = 8.0 Hz). HRMS (ESI, m/z): [M + H]+ calcd for
C38H45N4P2, 619.3114; found, 619.3114 (Δ = < 0.1 ppm).
red-TNSB BDP (8). (47.5 mg, 76% yield). Colorless needles were
obtained by gas-phase diffusion of pentane into a CH2Cl2 solution of
8. 1H NMR (CDCl3, 400 MHz, ppm): δ 8.10 (m, 2H), 7.95 (m, 4H),
7.77 (d, 3JH−H = 8.1 Hz, 2H), 7.54 (t, 3JH−H = 7.5 Hz, 4H), 7.49−7.28
(m, 10H), 6.48 (bs, 2H), 6.67 (bs, 6H), 6.40 (bs, 2H), 4.62 (bs, 4H),
2.88 (app. bd, J = 11.6 Hz, 2H), 2.60 (app. bd, J = 8.0 Hz, 2H), 2.47
(app. bt, J = 10.4 Hz, 2H), 1.80 (app. bt, J = 11.1 Hz, 2H), 1.50−1.24
(m, 8H). 13C{1H} NMR (CDCl3, 126 MHz, ppm): δ 144.5, 134.0 (br
s), 133.7, 13.32 (br s), 133.28, 131.32, 131.29, 130.5, 128.8, 128.8 (vt,
1JC−P = 5.0 Hz), 128.1, 127.3, 127.2, (br s) 126.2, 125.9 (br s), 126.5
dd, J = 18.0, 7.8 Hz, 6H), 7.70 (app. dt, J = 19.8, 6.9 Hz, 4H), 7.48 (t,
3JH−H = 7.7 Hz, 2H), 7.25 (app. dd, J = 23.4, 7.6 Hz, 4H), 7.10 (s, 4H),
6.92−6.85 (m, 4H), 6.71 (t, 3JH−H = 11.6 Hz, 2H), 6.57 (t, 3JH−H = 7.7
Hz, 2H), 6.46 (d, 3JH−H = 7.2 Hz, 2H), 6.11 (vt, 2JH−P = 6.9 Hz, 2H),
5.86 (s, 2H), 2.78 (td, 2JH−H = 15.9, 3JH−H = 15.9, 3JH−H = 4.9 Hz, 2H),
2
3
2
2.49 (dd, JH−H = 16.7, JH−H = 3.2 Hz, 2H), 2.36 (dd, JH−H = 16.7,
3JH−H = 3.2 Hz, 2H), 2.08 (td, 2JH−H = 16.1, 3JH−H = 16.1, 2JH−H = 4.7
Hz, 2H). 13C{1H} NMR (CDCl3, 126 MHz, ppm): δ 167.7, 165.6,
2
2
140.0 (vt, JC−P = 1.8 Hz), 134.53 (vt, JC−P = 10.0 Hz), 134.3, 132.7,
2
2
131.1 (vt, JC−P = 2.0 Hz), 130.84 (vt, JC−P = 2.1 Hz), 130.82, 130.4,
129.5, 128.9, 128.6, 128.1, 127.7, 126.6, 126.5, 126.0, 125.7, 125.5,
1
1
125.2, 125.1 (vt, JC−P = 8.3 Hz), 124.31, 123.1 (vt, JC−P = 3.1 Hz),
121.55, 59.8 (vt, 1JC−P = 18.5 Hz), 55.1 (vt, 1JC−P = 4.2 Hz), 30.4, 26.9.
31P{1H} NMR (CDCl3, 162 MHz, ppm): δ 3.27. HRMS (ESI, m/z):
[M + H]+ calcd for C58H45N4O4P2, 923.2911; found, 923.2914 (Δ =
0.3 ppm).
2
(br s), 125.2, 125.0, 124.4, 124.3, 123.6, 122.6 (vt, JC−P = 2.3 Hz),
69.6, 55.7, 55.1, 29.9, 25.9, 24.1. 31P{1H} NMR (CDCl3, 162 MHz,
ppm): δ −2.2. HRMS (ESI, m/z): [M + H]+ calcd for C58H53N4P2,
867.3740; found, 867.3737 (Δ = 0.3 ppm).
General Borane Reduction Procedure. To a mixture of the
BDP ligand (437.9 mg, 0.606 mmol, 1 equiv) in THF (7 mL), BH3·
THF (1 M in THF, 9.10 mL, 9.10 mmol, 15 equiv) was added via
syringe. The Schlenk flask was sealed, and the mixture was stirred at 55
°C or at room temperature for 20 h. The reaction mixture was allowed
to cool to room temperature, and all volatiles were removed in vacuo.
The remaining solid was dissolved in HNEt2 (3 mL), and the solution
was heated at 50 °C for at least 4 h. Upon cooling, all volatiles were
removed in vacuo. The crude product was dissolved in EtOAc (15 mL)
and stirred with aq. HCl (1 M, 10 mL) for at least 30 min. Aqueous
K2CO3 (10 wt %,) was added until the aqueous layer was basic (pH
∼10). The aqueous layer was extracted and washed with EtOAc (at
least 2 × 5 mL). The combined organic layers were washed with aq
K2CO3 (10 wt %, 2 × 7 mL) and dried over MgSO4. The solvent was
removed in vacuo to obtain the desired crude product as an off-white
solid, which was further purified by column chromatography or
recrystallization.
General Hydroformylation Procedure. Inside an N2-filled
glovebox, a solution of [Rh(acac)(CO)2] in THF (20 mM), a
solution of the bisdiazaphospholane ligand in DCM (5−20 mM), or
the reduced bisdiazaphospholane in THF (20 mM) and THF were
combined into an oven-dried 15 mL Ace Glass pressure bottle
equipped with a magnetic stir bar using 1000 and 200 μL of Eppendorf
pipets. The pressure bottle was attached to a pressure reactor and
removed from the glovebox. In a fume hood, the reactor was purged
with syngas (3 × 120 psig) and then filled to 150 psig of syngas. The
yellow solution was vigorously stirred at 60 °C for at least 60 min.
Upon cooling, the reactor was depressurized to 10 psig, and the alkene
was injected via a gastight syringe. Solid alkenes were injected as a
solution in THF. The reactor was then purged with syngas (3 × 120
psig) and filled to 150 psig of syngas. The reaction was heated at 40,
60, or 80 °C. After the desired reaction time, the reactor was allowed
to cool to room temperature and vented to atmospheric pressure.
NMR spectra of the crude reaction mixture were taken in CDCl3 or
toluene-d8 to obtain conversions of the alkenes and branched to linear
ratios of the produced aldehydes.
red-TPSB BDP (2). 2 was obtained as colorless block crystals upon
slow evaporation of EtOAc (89% yield). 1H NMR (CDCl3, 400 MHz,
ppm): δ 7.69 (m, 2H), 7.37−7.16 (m, 12H), 6.72−6.60 (m, 6H), 6.40
(t, J = 7.4 Hz, 4H), 4.09 (vt, 2JH−P = 12.5 Hz, 2H), 3.96 (brs, 2H), 2.94
(app. dd, J = 23.5, 11.4 Hz, 4H), 2.47 (app. td, J = 11.4, 2.9 Hz, 2H),
2.01 (app. td, J = 11.4, 2.9 Hz, 2H), 1.62−1.33 (m, 8H). 13C{1H}
NMR (CDCl3, 126 MHz, ppm): δ 141.9 (brs), 141.0 (brs), 136.6,
ASSOCIATED CONTENT
* Supporting Information
■
S
The Supporting Information is available free of charge on the
2
1
132.8 (vt, JC−P = 1.9 Hz), 129.2 (vt, JC−1P = 3.7 Hz), 128.0, 127.8,
127.5 (brs), 127.0, 126.8 (brs), 71.8 (vt, JC−P = 10 Hz), 71.2, 55.4,
54.9, 24.7, 24.0. 31P{1H} NMR (CDCl3, 162 MHz, ppm): δ −0.9.
HRMS (ESI, m/z): [M + H]+ calcd for C42H45N4P2, 667.3114. found:
667.3105 (Δ = 1.3 ppm).
WINDNMR simulations, NMR spectra for ligands 1, 2,
4−8, and TPSB BDPEO, X-ray structure of ligands 1, 2,
4, 7, 8 and [Rh(acac)(1)], additional calculations (PDF)
Corresponding XYZ coordinates (XYZ)
red-TPPB BDP (4). The pure product was obtained by
recrystallization from liquid−liquid diffusion of EtOAc and pentane
at room temperature (92% yield). 1H NMR (CDCl3, 400 MHz, ppm):
δ 7.78 (m, 2H), 7.37−7.20 (m, 12H), 7.15−7.04 (m, 6H), 6.99 (d,
3JH−H = 7.2 Hz, 2H), 6.89 (d, 3JH−H = 7.2 Hz, 2H), 6.85 (t, 3JH−H = 7.2
Accession Codes
lographic data for this paper. These data can be obtained free of
Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: +44 1223 336033.
3
3
Hz, 2H), 6.80 (d, JH−H = 7.4 Hz, 4H), 6.64 (t, JH−H = 7.7 Hz, 4H),
2
4.25 (vt, JH−P = 11.7 Hz, 2H), 4.20 (bs, 2H, overlapped with 4.18
ppm signal), 4.10 (d, 2JH−H = 14.5 Hz, 2H), 3.98 (d, 2JH−H = 14.5 Hz,
2H), 3.51 (d, JH−H = 14.5 Hz, 2H). 13C{1H} NMR (CDCl3, 126
2
MHz, ppm): δ 142.1, 141.1 (vt, JC−P = 8.6 Hz), 135.8, 133.7, 133.3,
133.2, 128.7 (vt, JC−P = 3.5 Hz), 128.4, 128.2, 127.5, 127.0, 126.2,
126.1, 126.0, 125.8, 72.7 (vt, JC−P = 9.2 Hz), 71.6, 58.7, 57.6. 31P{1H}
NMR (CDCl3, 162 MHz, ppm): δ 1.1. HRMS (ESI, m/z): [M + H]+
calcd for C50H45N4P2, 763.3114. found: 763.3105 (Δ = 1.4 ppm).
red-TPSB BDPE (6). Product 6 was obtained through air-free
extraction using N2-sparged EtOAc, aq HCl (1 M) and aq K2CO3.
MgSO4 was degassed prior to use. The sample also contains small
AUTHOR INFORMATION
Corresponding Author
■
ORCID
H
Organometallics XXXX, XXX, XXX−XXX