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

Figure S110. 31 P{ 1 H} NMR.
F. Reduction of trans-[(Ph 2P(CH 2) 3B(C 8H 14)) 2Re(<strong>CO</strong>) 4][BF 4] ([1-P 2][BF 4]).
Reaction of [1-P 2][BF 4] with 1 equiv NaHBEt 3.
A scintillation vial was charged with 40.7 mg (0.0376 mmol) cation [1-P 2][BF 4] and 0.5 mL
C 6D 5Cl. With rapid stirring, 37.6 μL (0.0376 mmol) NaHBEt 3 (1.0 M in toluene) was added
dropwise. The colorless solution turned yellow. The reduced species, [2-P 2] n, synthesized in situ
in this manner was stable for ~ 24 hours, after which time a significant amount of white
precipitates had formed. [2-P 2] n could be characterized by NMR spectroscopy in the presence of
toluene and BEt 3 from the borohydride reagent. 1 H NMR (C 6D 5Cl, 300 MHz): δ 1.36 (br, 12H),
1.7-2.1 (br m, 24H), 2.65 (br, 4H, Ph 2PCH 2CH 2CH 2B(C 8H 14)), (7.0-7.2 m, toluene obscures
Ph 2PCH 2CH 2CH 2B(C 8H 14) peak), 7.5 (m, 8H, Ph 2PCH 2CH 2CH 2B(C 8H 14)), 14.09 (s, 1H, Re-
CHO). 31 P{ 1 H} NMR (C 6D 5Cl, 121 MHz): δ 6.7 (br). 13 C{ 1 H} NMR (C 6D 5Cl, 125 MHz): 19.4
S98