... The 31 P{ 1 H} NMR spectrum of 3-OTf 2 in CD 3 CN displays a single resonance at 35.1 ppm, shifted slightly upfield from ... Figure 2). Analysis of the first-order rate plots revealed initial observed rate constants (k obs ) of 1.1 × 10 –3 and 8.4 × 10 –5 s –1 ... 1, 2-OTf 2, 4%, 5a, 68, 27. ...