Homogeneous CO Hydrogenation: Ligand Effects on the Lewis Acid ...

was apparent. Attempts to isolate and purify the material were met with failure, as removal of
solvents and redissolution in THF showed marked decomposition. The nature of this
decomposition remains unknown. The general structure of the product, containing a C-C bond
and cis-oriented phosphines, was deduced by multinuclear and multidimensional NMR
techniques. 1 H NMR (THF-d 8, 600 MHz): δ 0.25 (1H), 0.55 (dd, J = 13.8, 27.7 Hz), 1.1-2.0 (m,
overlapping with THF-d 8), 2.64 (dd, J = 13.0, 24.7 Hz, 1H), 2.8 (m, 1H), 2.93 (t, J = 13.3 Hz,
1H), 4.32 (d, J HH = 16.6 Hz, 1H), 4.82 (d, J HH = 16.6 Hz, 1H), 7.34 (m, 2H), 7.40 (t, J = 7.1 Hz,
2H), 7.64 (t, J = 8.1 Hz, 2H), 7.68 (m, 2H), 8.11 (t, J = 8.4 Hz, 2H). 31 P{ 1 H} NMR (THF-d 8, 121
MHz): δ 52.8 (d, J PP = 27.0 Hz), 60.1 (d, J PP = 26.8 Hz). 13 C{ 1 H} NMR (THF-d 8, 151 MHz): δ
13.05 (br), 15.38 (br), 23.35, 26.74, 27.25 (br), 27.55, 31.48 (d, JPC = 26.5 Hz), 31.87, 32.95,
33.61 (br), 33.92, 34.13 (d, J PC = 14.2 Hz), 34.45 (br), 34.85, 34.98, 35.20, 92.85 (Mn=C(O-
)CH 2O-), 127.77 (d, J PC = 8.0 Hz), 127.94 (d, J PC = 8.3 Hz), 128.13, 128.47 (d, J PC = 8.0 Hz),
128.64, 129.63, 132.45 (d, J PC = 7.4 Hz), 133.93 (d, J PC = 8.2 Hz), 134.20 (d, J PC = 8.7 Hz),
134.92 (d, J PC = 10.5 Hz), 139.15 (d, J PC = 25.9 Hz), 142.99 (d, J PC = 37.0), 143.44 (d, J PC = 20.0
Hz), 143.9 (d, J PC = 38.3 Hz), 229.49 (dd, J PC = 15.0, 17.8 Hz, <strong>CO</strong>), 231.11 (dd, J PC = 23.6, 30.6
Hz, <strong>CO</strong>), 331.45 (m, Mn=C(O-)CH 2O-). IR (THF). 1935 (m), 1852 (s) cm -1 . A broad stretch at
1902 cm -1 appeared to be an impurity.
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