Pyridine-promoted Cyclization of Functionalized N-Silylated Boron-Nitrogen Compounds

Dichloroboryldisilylamines [SiClm(CH3)3−m]N[Si(CH3)3](BCl2) (m = 1 – 3) as well as chloromethylboryl-bis-(chlorodimethylsilyl)amine [SiCl(CH3)2]2N[BCl(CH3)] form 1 : 1 adducts with pyridine (1 – 4). Those with m = 2 and 3 have been converted into functionalized diazadiboretidine derivatives which are still coordinated by pyridine: [(SiClm(CH3)3−m)NBCl · Py]2 (5: m = 2, 6: m = 3). Single-crystal X-ray diffraction structure analyses confirm the presence of planar, rhombusshaped, four-membered boron-nitrogen rings with tetra-coordinated boron atoms and nitrogenbonded, chlorine-functionalized silyl groups, for both compounds.