PUB - Publikationen an der Universität Bielefeld

Dilithiated N,N'-dimethyl-piperazine, LiCH2N(CH2CH2)(2) NCH2Li (2) was prepared by transmetallation of N,N'-bis(trimethylstannylmethyl)-piperazine (1) with (BuLi)-Bu-n and was isolated as a highly pyrophoric yellowish powder in high yield. Compound 2 was characterized by elemental analysis and was reacted as difunctional aminomethylating reagent with dialkyl-earth metal chlorides, R2MCl (M=Al, Ga; R=Me, Bu-t) which resulted in the formation of spirocyclic adducts of N,N'-bis(dialkylmetallamethyl)-piperazine and unreacted dialkylmetal chlorides, [(Me2AlCl)Me2-AlCH2N(CH2CH2)(2)NCH2AlMe2(ClAlMe2)] (3) and [((Bu2GaCl)-Bu-t)t-Bu2GaCH2N(CH2CH2)(2)(NCH2GaBu2)-Bu-t((ClGaBu2)-Bu-t)] (4) with five-membered rings. Compounds 1, 3 and 4 were identified by NMR-spectroscopy (H-1, C-13, Sn-119 for 1, Al-27 for 3), mass spectra (EI, for 1) and by crystal structure determinations.