Synthesis, Reactivity, and Resolution of a C2–Symmetric, P–Stereogenic Benzodiphosphetane, a Building Block for Chiral Bis(phosphines)

Although the pyramidal inversion barriers in diphosphines (R2P–PR2) are similar to those in phosphines (PR3), P-stereogenic chiral diphosphines have rarely been exploited as building blocks in asymmetric synthesis. The synthesis, reactivity, and resolution of the benzodiphosphetane trans-1,2-(P(t-Bu))2C6H4 are reported. Alkylation with MeOTf followed by addition of a nucleophile gave the useful C2-symmetric P-stereogenic ligand BenzP* and novel analogues.