All nonaqueous reactions were run under an inert atmosphere (argon) with flame-dried or oven-dried glassware using standard techniques. Anhydrous solvents were obtained by filtration through drying columns (toluene, CH2Cl 2 ) or used directly from commercial sources (MeCN) without drying. Reactions that required thermal activation were heated using a water bath (for temperatures up to 25 °C) or a silicone oil bath (for temperatures >25 °C). Flash column chromatography was performed using 230-400 mesh silica with the indicated solvent system according to standard techniques. Analytical thin-layer chromatography (TLC) was performed on precoated, glassbacked silica gel plates. Visualization of the developed chromatogram was performed by UV absorbance (254 nm) or aqueous potassium permanganate stains. Infrared spectra (nmax, FTIR ATR) were recorded in reciprocal centimeters (cm -1 ).