Transformations of molecular nitrogen into aromatic amines under the action of titanium compounds

The paper describes remarkable reactions of the direct synthesis of aromatic amines from molecular nitrogen. Two types of systems capable of inducing such reactions are considered in detail. The first type involves systems based on titanium compounds (Cp₂TiCl₂, Cp₂TiPh₂, CpTiCl₃, TiCl₄, Ti(OBu)₄) and excess aryllithium reagents (PhLi, p-, m- and o-MeC₆H₄Li, -C₁₀H₈Li, oPhC₆H₄Li) in ether. The second type is obtained by treating diaryltitanocenes Cp₂TiAr₂ (Ar = Ph, p- and m-MeC₆H₄) with metals of groups I and II (Li, Na, Mg) in ethereal media. In both cases the interaction with dinitrogen proceeds at room temperature and results in the formation of aromatic amines and ammonia after hydrolysis. The highest activity in amine production is displayed by the systems Cp₂TiCl₂ + PhLi in ether and Cp₂TiPh₂ + Li in THF. The mechanism of the reactions found is discussed.