Bor-stabilisierte N,O-Carbene, I Triphenylbor-Addukte von Siloxy-und Hydroxyalkylisocyaniden und spontane At-Ylid-Bildung / Boron-Stabilized N.O-Carbenes, I Triphenylboron Adducts of Siloxy- and Hydroxyalkyl Isocyanides and Spontaneous Formation of Ate-Ylids

. Triphenylboron adducts of 2- and 3-hydroxyalkyl isocyanides spontaneously undergo intramolecular cyclization to give oxazolidin-2-ylidene and perhydrooxazin-2-ylidene boron complexes, respectively. The same compounds are obtained by methanolysis of the stable species Ph3B-CNCR1R2CR3R4-OSiMe3 (R1, R2, R3, R4 = H, alkyl) (2a-i) and Ph3B-CN(CH2)3-OSiMe3 (2j)IR, 1H NMR, 13C{H} NMR. and mass spectra of the new compounds are reported.