Syntheses and Reactivity of Aminobis(diorganylamino)phosphanes

Aminobis(diorganylamino)phosphanes (R2N)2PNH2 (R = iPr, c‐Hex, Ph) (2a–c), were obtained by treatment of the corresponding chlorobis(diorganylamino)phosphanes 1a–c with lithium amide in liquid ammonia. The transition metal phosphane complex (R2N)2(H2N)PNi(CO)3 (3) was prepared by reaction of 2a with tetracarbonylnickel. N‐Complexation of 2a with trimethylalane affords the iminophosphorane‐alane adduct (R2N)2HP=N(H)AlMe3 (4) by 1,2‐H shift from the nitrogen to the phosphorus atom. The corresponding reaction with aluminium trichloride leads to the formation of the salt [(R2N)2HP=N(H)]2AlC12+[AlC14]− (5), in which two iminophosphorane moieties are linked by an AlCl2 bridge. Lithiation of 2a and subsequent reaction with titanocene dichloride result in nucleophilic replacement of one chlorine atom to give the phosphanylamido‐substituted titanocene compound (R2N)2P–N(H)Ti(Cl)Cp2 (6a), which rearranges to its P‐hydroiminophosphorane tautomer (R2N)2P(H)=NTi(Cl)Cp2 (6b) on gentle heating. No isomerisation was observed in the case of N‐borylated aminophosphane (R2N)2P–NH–(9‐BBN) (7), obtained by reaction of lithiated 2a with B‐Cl‐9‐BBN. The X‐ray structure analyses of compounds 2b, c, 3, 4, 5, and 6a are discussed.