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

Figure S124. 31 P{ 1 H} NMR.
Reaction of 2-E 2 with 2-M 2.
Boroxycarbene 2-E 2 was first prepared, by addition of 21.0 mg (0.0327 mmol) solid [HPt] + to a
stirring ~0.6 mL C 6D 5Cl solution of 52.8 mg (0.0327 mmol) [1-M 2][B(C 6F 5) 4] and 16.0 mg
(0.0327 mmol) tetraheptylammonium tetrafluoroborate. The solution was transferred to a J-
Young NMR tube, and was allowed to react overnight. A few days later, boroxycarbene 2-E 2
was prepared by dropwise addition of 32.7 µL (0.0327 mmol) NaHBEt 3 (1.0 M in toluene) to a
stirring ~0.4 mL C 6D 5Cl solution of 34.5 mg (0.0327 mmol) [1-E 2][BF 4]. The preformed 2-M 2
was returned to the glove box (NMR spectroscopy showed no decomposition during the days
after preparation), and the contents of the tube were poured onto the solution containing 2-E 2.
The reaction mixture was filtered through sintered glass into a J-Young NMR tube, and
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