The first examples of enantiomerically pure diphosphane dioxides-(R(P),R(P))- and (S(P),S(P))-1,2-di-tert-butyl-1,2-diphenyldiphosphane 1,2-dioxides, and (R(P))- and (Sp)-1-tert-butyl-1,2,2-triphenyldiphosphane 1,2-dioxides

Whereas oxidative dimerization of each of the lithiated reagents (R(P))- and (S(P))-tert-butylphenylphosphane oxides 1 Li and 2 Li by means of oxygen in THF at low temperature led cleanly to meso-1,2-di-tert-butyl-1,2-diphenyldiphosphane dioxide (3), the respective nucleophilic substitution reactions of 1 Li and 2 Li with the (R(P))- and (S(P))-tert-butylphenylphosphinic bromides (4 and 6) in THF under argon led to the corresponding (S(P),S(P))-and (R(P),R(P))-1,2-di-tert-butyl-1,2-diphenyldiphosphane dioxides (5 and 7) in good yields together with the meso-diphosphane dioxide 3. The structures of 3 and 5 were established by X-ray crystallography. Similarly, the reaction of lithiated (R(P))-phosphane oxide 1 Li with diphenylphosphinic bromide (8) or of achiral lithiated diphenylphosphane oxide 10 Li with (R(P))-tert-butylphenylphosphinic bromide (4) provided (S(P))-tert-butyltriphenyldiphosphane dioxide (9).