Taming a Functional Group: Creating Air-Stable Primary Phosphanes

With the exception of the oxidation experiments, all reactions were carried out under a nitrogen atmosphere using standard Schlenk-line techniques. Solvents were dried according to standard procedures1 except DMSO, which was purchased in an anhydrous state from Aldrich. Palladium (II) actetate was purified by filtration from hot toluene. Supermesityl phosphane 1a was prepared as in the literature.2 The d-chloroform was purged with nitrogen and stored over molecular sieves. Analytical TLC was performed on Merck precoated silica gel 60 F254. Flash Chromatography3 was performed on Merck silica gel 60 (0.040-0.063 mm). Columns (up to 4.0 cm diameter) were pressurized using an air pump. The NMR spectra were recorded at 25 ˚C on a Varian Inova 300 MHz spectrometer with chemical shifts relative to tetramethylsilane for routine 1H and 13C spectra and 85 % H3PO4 for 31P spectra. The numerous 1H-1H COSY, 13C{1H}, DEPT, HSQC, HMQC and 31P-1H HMBC NMR spectra taken for (R)