Syntheses and Reactivity of Aminobis(diorganylamino)phosphanes

Abstract

Abstract Aminobis(diorganylamino)phosphanes (R 2 N) 2 PNH 2 (R = i Pr, 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 (R 2 N) 2 (H 2 N)PNi(CO) 3 ( 3 ) was prepared by reaction of 2a with tetracarbonylnickel. N ‐Complexation of 2a with trimethylalane affords the iminophosphorane‐alane adduct (R 2 N) 2 HP=N(H)AlMe 3 ( 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 [(R 2 N) 2 HP=N(H)] 2 AlC1 2 + [AlC1 4 ] − ( 5 ), in which two iminophosphorane moieties are linked by an AlCl 2 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 (R 2 N) 2 P–N(H)Ti(Cl)Cp 2 ( 6a ), which rearranges to its P ‐hydroiminophosphorane tautomer (R 2 N) 2 P(H)=NTi(Cl)Cp 2 ( 6b ) on gentle heating. No isomerisation was observed in the case of N ‐borylated aminophosphane (R 2 N) 2 P–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.