The Electronic and Steric Effects of Neutral and Ionic Phosphines on Ir(I)-complex Catalyzed Hydroaminomethylation of Olefins

The electronic and steric effects of a series of neutral and ionic (mono-/di-)phosphines on the performance of Ir (I)-complex catalysts for the hydroaminomethylation of olefins were systematically investigated by means of (1)J(31)P-(77) Se coupling constant measurement, single-crystal X-ray diffraction, and high pressure in situ FTIR spectroscopy. It was found that the neutral mono-phosphines of Ll with the moderate ms-accepting nature ( (1)J(31)P-Se-77 of 753 Hz) and relatively less steric hindrance was able to spur the activities of the corresponding Ircatalysts. In addition, the catalytic performances over the lr(I)- and Rh(I)-precursors was compared under the same reaction conditions. The advantages of kW-catalyst over Rh(I)-catalyst for this tandem reaction were also discussed in detail.