Reactions of t-Butylphosphine–Borane with Various Electrophiles and Synthesis of Optically Active t-Butylmethylphosphine–Borane

The reactivity of t-butylphosphine–borane toward various electrophiles was studied with a focus on alkylation. Monoalkylation of this compound proceeded smoothly in good yields (61–85%). Disubstituted derivatives were also synthesized in good yields (86–99%). Optically active t-butylmethylphosphine–borane was prepared from t-butylphosphine–borane by resolution of intermediate diastereomers of (1S)-endo-2-bornyloxycarbonyl(t-butyl)methylphosphine-borane.