A group of seven achiral, α- and β-chiral dialkylphosphanes were synthesized in one step from sodium phosphide and alkyl sulfonates or sulfates. The corresponding borane complexes were further alkylated with alkyl, allyl, and benzyl bromides and mesylates to give tertiary mono- and diphosphanes, either via lithium phosphide-borane complexes at low temperature (45-78%) or under phase-transfer conditions (79-91%).
In the course of an ongoing synthetic project, we observed an unprecedented reactivity of N-methyl groups in bis(N,N-dimethylaminoethylferrocenyl)phenylphosphinesulfide upon treatment with manganese dioxide (MnO2). The intramolecular course of this reaction resulted in the formation of an unexpected homochiral diaza macrocycle. The target structure was accessible in two steps from known N,N-dimethylaminoethylferrocene.