SYNTHESIS, STRUCTURE, AND REACTIVITY OF BIS(DIALKYLAMINO)DIPHOSPHINES

Starting with the aminochlorophosphines iPr2N-PCl2, 1 and (iPr2N)2P-Cl 2, the synthesis of some new functionalized aminophosphines (iPr2N)2P-SiMe3 3a, (iPr2N)2P-SnMe3 3 b, (iPr2N)(DMP)P-Cl 4, iPr2N-P(SiMe3)2 5 and iPr2N-P(SiMe3)Cl 6 is reported. Reactions of 2 with different phosphides yield the aminodiphosphines (iPr2N)2P-P(SiMe3)2 7a, (iPr2N)2P-P(SiMe2tBu)2 7b, (iPr2N)2P-PPh2 8 and (iPr2N)2P-PH2 9. The phosphines 3a/b react with halogenophosphines to the aminohalogenodiphosphines (iPr2N)2P-PCl2 10, (iPr2N)2P-PtBuCl 11 and (iPr2N)2P-P(NiPr2)Cl 12. The ambivalente aminophosphine 6 gives the aminotrichlorodiphosphine Cl(iPr2N)P-PCI2 13 after condensation with PCl3, While the reactions with the corresponding lithumphosphides yield the aminosilyldiphosphines (iPr2N)(SiMe3)P-P(SiMe3)2 14a and (iPr2N)(SiMe3)P-P(SiMe2tBu)2 14b. The aminochlorophosphines 2/4 are reductively coupled with magnesium leading to the symmetrically substituted tetraaminodiphosphines (iPr2N)2P-P(iPr2N)2 15a and DMP(iPr2N)P-P(iPr2N)DMP 15b. The functionalized aminosilyldiphosphine 7a is treated with methanol to yield the diphosphine (iPr2N)2P-PH(SiMe3) 16 and gives the lithium phosphinophosphide (iPr2N)2P-PLi(SiMe3) 17 after metallation with n-BuLi. The compounds are characterized by their NMR and mass spectra and the P-31-NMR values of the diphosphines are discussed according to their substituents. The crystal structures of 7b, 8 and 15b showing significantly differing conformations are presented.