Dehalogenation of RzNPC12 (R= isopropyl or cyclohexyl) with magnesium in tetrahydrofuran gives the corresponding cyclotetraphosphines (R2N) 4P4; the corresponding biphosphines (i-PrzN) 2PzX2 (X= C1 and Br) can be isolated from reactions of i-Pr2NPX2 with more limited quantities of magnesium. Dehalogenations with magnesium of R2NPC12 derivatives having R2N groups smaller than diisopropylamino lead to ...
