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

I. General Considerations.
All air- and moisture-sensitive compounds were manipulated using standard vacuum line or
Schlenk techniques, or in a glovebox under a nitrogen atmosphere. Under standard glovebox
conditions, petroleum ether, diethyl ether, benzene, toluene, and tetrahydrofuran were used
without purging, such that traces of those solvents were in the atmosphere, and could be found
intermixed in the solvent bottles. The solvents for air- and moisture-sensitive reactions were
dried over sodium benzophenone ketyl, calcium hydride, or by the method of Grubbs. 1 All NMR
solvents were purchased from Cambridge Isotopes Laboratories, Inc. Benzene-d 6 was distilled
from sodium benzophenone ketyl or titanocene. Dichloromethane-d 2 and chlorobenzene-d 5 were
distilled from calcium hydride and run through a small column of activated alumina.
Tetrahydrofuran-d 8 was purchased in a sealed ampoule, and dried by passage through activated
alumina. Unless noted, other materials were used as received. Re(<strong>CO</strong>) 5Br was purchased from
Strem Chemicals, Inc. Re(<strong>CO</strong>) 5OTf, 2 trans-Re(PPh 3)(<strong>CO</strong>) 4I, 3 trans-[(PPh 3) 2Re(<strong>CO</strong>) 4][BF 4], 4
Ph 2P(CH 2) 2B(C 8H 14), 5 [(Ph 2P(CH 2) 2B(C 8H 14)) 2Re(<strong>CO</strong>) 4][BF 4], 6 boroxycarbene 2-E 2, 6
boroxymethylboroxycarbene [3-E 2] - , 6 Cl-9-BBN, 7 Ph 2PCH 2Li, 8
t Bu(CH2) 2B(C 8H 14), 9
[Pt(dmpe) 2][PF6] 2 ([Pt][PF6] 2), 10 and NaBAr F 11 F
4 (BAr 4 = [B(C6H3(3,5-(CF3) 2) 4]) were
synthesized according to literature procedures. Elemental analyses were performed by Robertson
Microlit Laboratories, Madison, NJ. 1 H and 13 C NMR spectra were recorded on Varian Mercury
300, 400-MR, INOVA-500 or -600 MHz spectrometers at room temperature, unless indicated
otherwise. Chemical shifts are reported with respect to residual internal protio solvent for 1 H and
13 C{ 1 H} spectra. Other nuclei were referenced to an external standard: H3PO 4 ( 31 P), 15%
BF 3•Et 2O/CDCl 3 ( 11 B), CFCl 3 ( 19 F), all at 0 ppm. High resolution mass spectra (HRMS) were
obtained at the California Institute of Technology Mass Spectrometry Facility.
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