The Journal of Organic Chemistry
Page 6 of 12
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1.62 (s, 3H, CH3), 1.78 (s, 3H, CH3), 1.92 (d, 3H, CH3-N, JH-P
=
1.21 (d, CH3-CH, JH-H= 6.7 Hz), 1.53 (s, CH3, 18H, Bu), 1.66 (s,
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7.8 Hz), 1.98 (s, 3H, CH3), 2.06 (s, 3H, CH3), 2.09-2.14 (m, 1H,
CH3), 1.74 (CH3), 1.95 (d, CH3-N, JH-P= 3.5 Hz), 2.01 (s, 3H,
CH, iPr), 4.36-4.42 (m, 1H, CH-N), 5.50 (dd, 1H, CH-O, 3JH-P= 8.8
CH3), 2.07 (s, 3H, CH3), 3.74-3.84 (m, 1H, CH-N), 5.23 (pt, CH-
O, J= 8.9 Hz), 6.70-6.74 (m, 2H, CH=), 6.94-6.99 (m, 4H, CH=),
7.04-7.16 (m, 5H, CH=), 7.47-7.49 (m, 2H, CH=). 13C{1H} NMR
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Hz, JH-H= 4.5 Hz), 6.97-7.01 (m, 4H, CH=), 7.07-7.16 (m, 4H,
CH=), 7.50-7.54 (m, 2H, CH=), 7.62-7.64 (m, 2H, CH=). 13C{1H}
NMR (100.6 MHz, C6D6): δ= 11.5 (CH3-CH), 15.4 (CH3), 16.1
(CH3), 16.4 (CH3), 16.5 (d, CH3, J= 5.5 Hz ), 20.0 (d, CH3, J= 3.1
1
(100.6 MHz, C6D6): δ= 12.2 (d, CH3-P, JC-P= 22.2 Hz), 16.2
3
(CH3), 16.4 (d, CH3-CH, JC-P= 4.7 Hz), 16.5 (CH3), 20.1 (CH3),
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Hz), 21.4 (CH3), 21.9 (CH3), 28.0 (d, CH3-N, JC-P= 4.2 Hz), 29.4
29.7 (d, CH3-N, JC-P= 8.9 Hz), 31.2 (d, CH3, Bu, JC-P= 5.3 Hz),
t
t
t
2
(CH-iPr), 31.2 (d, CH3, tBu, JC-P= 5.4 Hz), 31.4 (CH3, tBu), 34.5 (C,
31.6 (CH3, Bu), 34.6 (C, Bu), 34.8 (C, Bu), 64.8 (CH-N, JC-P=
tBu), 34.8 (C, Bu), 58.3 (d, CH-N, JC-P= 8.3 Hz), 82.3 (d, CH-O,
2JC-P= 4.4 Hz), 125.3-145.5 (aromatic carbons). HRMS (ESI-TOF)
m/z: [M+H]+ Calcd for C43H61BNO3P2 712.4214; Found
712.4218.
37.0 Hz), 80.7 (CH-O), 126.9-145.5 (aromatic carbons). HRMS
(ESI-TOF) m/z: [M+H]+ Calcd for C41H54NO3P2 670.3573; Found
670.3576.
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L1c: Yield: 60 mg (67%) (flash chromatography under argon
using neutral alumina and dry and deoxygenated
toluene/hexane (1:1) as eluent system (1% NEt3)). 31P{1H}
L3c·BH3: Yield: 203 mg (57%) (filtration under argon over
neutral silica using dry toluene/hexane (1:1) as eluent system
(1% NEt3)). 31P{1H} NMR (161.9 MHz, C6D6): δ= 141.0 (s, P-O),
1
NMR (161.9 MHz, C6D6): δ= 140.6 (s, P-O), 49.0 (s, P-N). H
1
1
78.6 (bs, P-N). H NMR (400 MHz, C6D6): δ= 0.94-0.96 (d, 3H,
NMR (400 MHz, C6D6): δ= 1.11 (d, 3H, CH3-P, JH-P= 6.5 Hz),
3
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CH3-CH, 4JH-P= 6.9 Hz), 0.99-1.05 (dd, 3H, CH3-iPr, J= 17.3 Hz, J=
7.0 Hz), 1.20-1.26 (dd, 3H, CH3-iPr, J= 15.4 Hz, J= 7.0 Hz), 1.49
1.40 (d, CH3-CH, JH-H= 6.7 Hz), 1.43 (s, CH3, 9H, Bu), 1.57 (s,
t
CH3, 9H, Bu), 1.63 (s, CH3), 1.99 (CH3), 2.06 (s, 3H, CH3), 2.09
(d, CH3-N, 2JH-P= 3.6 Hz), 3.72-3.78 (m, 1H, CH-N), 5.33 (pt, CH-
t
(s, 9H, CH3, Bu), 1.63 (s, 3H, CH3), 1.66 (s, 3H, CH3), 1.70 (s,
9H, CH3, tBu), 2.04 (s, 3H, CH3), 2.18 (s, 3H, CH3), 2.26-2.33 (m,
O, J= 7.7 Hz), 6.80-6.84 (m, 2H, CH=), 6.95-7.16 (m, 10H, CH=).
3
1
1H, CH-iPr), 2.47 (d, 3H, CH3-N, JH-P= 7.8 Hz), 4.54-4.61 (m,
13C{1H} NMR (100.6 MHz, C6D6): δ= 12.3 (d, CH3-P, JC-P= 21.4
Hz), 16.2 (CH3), 16.3 (CH3), 16.6 (d, CH3-CH, 3JC-P= 7.2 Hz), 20.0
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1H, CH-N), 5.74 (dd, 1H, CH-O, JH-P= 8.2 Hz, JH-H= 3.8 Hz),
6.96-7.32 (m, 10H, CH=), 7.65-7.67 (m, 2H, CH=). 13C{1H} NMR
(100.6 MHz, C6D6): δ= 11.3 (CH3-CH), 15.9 (CH3), 16.2 (CH3),
16.4 (CH3), 16.7 (CH3), 20.0 (CH3), 20.2 (CH3), 29.1 (d, CH3-N,
2JC-P= 4.2 Hz), 29.5 (CH-iPr), 31.0 (d, CH3, tBu, JC-P= 5.4 Hz), 31.5
(CH3, tBu), 34.4 (C, tBu), 34.8 (C, tBu), 58.2 (CH-N), 81.6 (CH-O),
121.0-150.6 (aromatic carbons). HRMS (ESI-TOF) m/z: [M+H]+
Calcd for C43H61BNO3P2 712.4214; Found 712.4219.
2
(CH3), 20.1 (CH3), 30.8 (d, CH3-N, JC-P= 8.0 Hz), 31.0 (d, CH3,
tBu, JC-P= 5.2 Hz), 31.5 (CH3, Bu), 34.4 (C, Bu), 34.7 (C, Bu),
64.8 (CH-N), 80.2 (CH-O), 125.3-145.6 (aromatic carbons).
HRMS (ESI-TOF) m/z: [M+H]+ Calcd for C41H54NO3P2 670.3573;
Found 670.3578.
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L3b: Yield: 92 mg (70%) (flash chromatography under argon
using neutral alumina and dry and deoxygenated
toluene/hexane (1:1) as eluent system (1% NEt3)). 31P{1H}
NMR (161.9 MHz, C6D6): δ= 143.6 (s, P-O), 70.4 (bs, P-N). H
NMR (400 MHz, C6D6): δ= 0.60-0.74 (m, 6H, CH3, Pr), 1.05 (d,
For deprotection, the borane-adduct (0.68 mmol) was
dissolved in dry and deoxygenated diethylamine (20 mL) and
heated to 55 ºC using an oil bath for 16 h. After this time, the
mixture was evaporated to dryness and the residue was
purified by flash chromatography to afford the corresponding
ligands as white solids.
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3H, CH3-CH, JH-H= 6.7 Hz), 1.49 (s, 9H, CH3, Bu), 1.52 (s, 9H,
CH3, tBu), 1.63 (s, 3H, CH3), 1.73 (s, 3H, CH3), 1.97 (d, 3H, CH3-
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N, JH-P= 3.7 Hz), 1.99 (s, 3H, CH3), 1.99-2.01 (m, 1H, CH, Pr),
2.06 (s, 3H, CH3), 3.82-3.92 (m, 1H, CH-N), 5.13-5.17 (m, 1H,
CH-O), 6.94-7.18 (m, 9H, CH=), 7.33-7.40 (m, 3H, CH=). 13C{1H}
NMR (100.6 MHz, C6D6): δ= 14.7 (CH3-CH), 16.1 (CH3), 16.4
(CH3), 17.5 (CH3), 17.7 (CH3), 17.9 (CH3), 18.0 (CH3), 19.9 (CH3),
L1a: Yield: 221 mg (75%) (flash chromatography under
argon using neutral alumina and dry and deoxygenated
toluene/hexane (1:1) as eluent system (1% NEt3)). 31P{1H}
NMR (161.9 MHz, C6D6): δ= 147.8 (bs, P-O), 49.5 (s, P-N). H
NMR (400 MHz, C6D6): δ= 1.10 (d, 3H, CH3-P, JH-P= 8.4 Hz),
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20.0 (CH3), 22.7 (d, CH-iPr, JC-P= 6.2 Hz), 29.6 (d, CH3-N, JC-P
=
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7.6 Hz), 31.2 (d, CH3, tBu, JC-P= 5.4 Hz), 31.6 (CH3, tBu), 34.5 (C,
1.24 (s, 9H, CH3, Bu), 1.26 (s, 9H, CH3, Bu), 1.31 (d, 3H, CH3-
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tBu), 34.7 (C, Bu), 65.5 (d, CH-N, JC-P= 36.7 Hz), 81.3 (CH-O),
125.3-145.5 (aromatic carbons). HRMS (ESI-TOF) m/z: [M+H]+
Calcd for C43H58NO3P2 698.3886; Found 698.3891.
CH, JH-H= 6.6 Hz), 1.48 (s, 9H, CH3, Bu), 1.53 (s, 9H, CH3, Bu),
3
2.08 (d, 3H, CH3-N, JH-P= 8.0 Hz), 3.73-3.80 (m, 1H, CH-N),
5.38 (pt, 1H, CH-O, J= 8.4 Hz), 6.82-6.86 (m, 1H, CH=), 6.96-
7.09 (m, 7H, CH=), 7.27 (s, 2H, CH=), 7.33-7.35 (m, 2H, CH=),
7.51-7.53 (m, 2H, CH=). 13C{1H} NMR (100.6 MHz, C6D6): δ=
L3c: Yield: 48 mg (68%) (flash chromatography under argon
using neutral alumina and dry and deoxygenated
toluene/hexane (1:1) as eluent system (1% NEt3)). 31P{1H}
NMR (161.9 MHz, C6D6): δ= 140.6 (s, P-O), 70.6 (bs, P-N). H
NMR (400 MHz, C6D6): δ= 0.79-0.87 (m, 6H, CH3, Pr), 1.24 (d,
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12.2 (d, CH3-P, JC-P= 21.7 Hz), 16.3 (d, CH3-CH, JC-P= 6.5 Hz),
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30.5 (d, CH3-N, JC-P= 8.2 Hz), 30.6 (CH3, Bu), 31.1 (CH3, Bu),
i
31.2 (d, CH3, tBu, JC-P= 5.4 Hz), 34.3 (C, tBu), 35.3 (C, tBu), 64.7
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(d, CH-N, JC-P= 38.1 Hz), 80.6 (CH-O), 123.9-146.4 (aromatic
3H, CH3-CH, JH-H= 6.8 Hz), 1.46 (s, 9H, CH3, Bu), 1.60 (s, 9H,
carbons). HRMS (ESI-TOF) m/z: [M+H]+ Calcd for C45H62NO3P2
726.4199; Found 726.4236.
CH3, tBu), 1.67 (s, 6H, CH3), 2.02 (s, 3H, CH3), 2.11 (s, 3H, CH3),
i
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2.13-2.15 (m, 1H, CH, Pr), 2.25 (d, 3H, CH3-N, JH-P= 3.7 Hz),
3.90-3.97 (m, 1H, CH-N), 5.34 (m, 1H, CH-O), 6.97-7.01 (m,
10H, CH=), 7.47 (m, 2H, CH=). 13C{1H} NMR (100.6 MHz, C6D6):
δ= 14.5 (CH3-CH), 15.6 (CH3), 16.1 (CH3), 16.3 (CH3), 17.5
(CH3), 17.8 (CH3), 18.2 (CH3), 19.9 (CH3), 20.0 (CH3), 22.6 (d,
L1b: Yield: 74 mg (60%) (flash chromatography under argon
using neutral alumina and dry and deoxygenated
toluene/hexane (1:1) as eluent system (1% NEt3)). 31P{1H}
NMR (161.9 MHz, C6D6): δ= 143.0 (s, P-O), 51.2 (s, P-N). H
NMR (400 MHz, C6D6): δ= 1.03 (d, 3H, CH3-P, JH-P= 6.3 Hz),
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CH-iPr, JC-P= 6.3 Hz), 29.4 (CH3-N), 31.4 (d, CH3, Bu, JC-P= 5.1
Hz), 31.5 (CH3, Bu), 34.3 (C, Bu), 34.7 (C, Bu), 65.7 (CH-N),
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