Synthesis of Aminophosphane Complexes: Searching the Boundary between Phosphanide and Phosphinidenoid Complex Chemistry

Aminophosphane complexes 3a–e have been prepared by two different pathways: (1) the thermal reaction of 2H‐azaphosphirene complex 1 with primary or secondary amine derivatives at 75 °C (3a,b,d,e) or (2) the reaction of chlorophosphane complex 2 with sodium diphenylamide (3c). In the latter case, complex 3c was obtained together with the diphosphene complex 6, thus providing evidence for the transient formation of Na/X phosphinidenoid complexes 4a,b and/or the terminal phosphinidene complex 5. Preliminary deprotonation studies, carried out on complex 3a by using lithium diisopropylamide in TMEDA in the presence of 12‐crown‐4 at low temperature, yielded a mixture of the Li/NMe2 phosphinidenoid complex 7 together with the nonligated phosphane derivative 8, which could not be separated. Complexes 3a,b,d,e and 6 were characterized by NMR and IR spectroscopy, MS, and elemental analysis. The structures of complexes 3c–e and 6 were confirmed by single‐crystal X‐ray diffraction analysis. Aminophosphane complexes 3a–e have been prepared by two routes. Complex 3c was obtained along with diphosphene complex 6, giving evidence for the formation of transient Na/X phosphinidenoid complexes 4a,b and/or phosphinidene complex 5. Initial studies on the deprotonation of 3a led to the formation of the Li/NMe2 phosphinidenoid complex 7a along with the nonligated phosphane derivative 8.