The methyl)-2-(alpha-naphthoxy)-1,3,2-dioxaphospholane (1) and thyl)-2
-dimethylamino-2-oxo-1,3,2-dioxaphospholane (2), analogues of the chir
al bisphosphine ligand DIOP, have been synthesized. Both compounds hav
e a second phosphorus functionality in the backbone of the chiral bisp
hosphine. That the reactivities of the various phosphorus atoms in 1 a
re different was shown for the reaction with BH3. The complexation beh
aviour of 1 towards Rh(I) was studied with the aid of P-31 NMR spectro
scopy.