Chemie der schweren Carben-Analogen R2M (M=Si, Ge, Sn). XIX. Reaktionen von stabilem Diaminogermylen und -stannylen Me2Si(t-BuN)2M (M=Ge, Sn) mit organischen Aziden

Article abstract of DOI:10.1016/0022-328X(94)87045-4

The reaction of Veith's germylene Me2Si(t-BuN)2Ge 1 with an excess of organic azides R-N3 2a-2i under elimination of N2, very probably gives the unstable, reactive germaimines Me2Si(t-BuN)2Ge=N-R that dimerize rapidly even at -40 deg C, yielding the dispirodecanes 4a-4g.At higher temperatures, however, the <2+3> dipolar cyclo-addition of a second molecule of R-N3 leading to 5-germa tetrazolines, 3a-3e, competes successfully.This depends on the nature of R, and is thermally reversible.Other scavengers are, e.g.Me3Sn-Cl or Me3Si-N3.With the corresponding Veith-stannylene 5, only dispiro compounds 4h-4k are obtained, and no 5-stanna tetrazoline. 1 and 5 exhibit, however, the same activity toward p-tolyl azide, leading, in a competitive experiment, to a statistical 1:1:2 distribution of the Ge2, Sn2, and Ge, Sn (4l) dispirodecanes.The stability of the tricyclic system 4 in most of the examples is very high.Thus, in the mass spectra of 4b, 4k, 4l the molecular peaks M⁺ (m/z=756, 848, 802) are the respective base peaks, followed by (M-Me)⁺.Doubly loaded ions (M-2Me)²⁺ are also surprisingly stable.Most of the obtained compounds are new. Key words: Group 14; Germanium; Tin; Azides; Carbene