The N-lithioborazine LiH 2 N 3 B 3 Me 3 , 1, reacts with organoboron halides not only to the respective borazinyl organylboranes but also by Me/halogen exchange. (Me 2 N) 2 B-H 2 N 3 B 3 Me 3 was obtained from 1 and (Me 2 N) 2 BCl. A new ten-membered B 6 N 4 ring system, 5, results on treatment of Cl(Me 2 N)B-B(NMe 2 )Cl with 1. The B-N-borazinyl borazines 6 - 8 can be prepared from 1 and B-monohalo borazines. The synthesis of 2,4,6-trimethylborazinyl-aluminum and -titanium compounds is achieved only with mononuclear monohalides of Al(III) and Ti(IV). The 2,4,6-trimethylborazinyl- bis(piperidino)alane 9 and the tris(2,6-diisopropylphenoxo)-2,4,6-trimethylborazinyltitanium 10 were characterized by X-ray structure analysis. The distortion of the borazine ring by B and N substitution is discussed. In case of the N-substituted borazines YH 2 N 3 B 3 Me 3 the B-N bonds of the YNB 2 units are elongated, e. g. for Y = PBr 2 or (RO) 3 Ti, while N lithiation leads to a shortening of these B-N bond. These changes of bond lengths are also reflected by changes in the B1-N2 and B3-N3 bond lengths which become shorter in the presence of electron-withdrawing groups, but longer in case of Li substitution. Also, the bond angles B1-N2-B2 and B2-N3-B3 are affected by an increase of up to 128°.