Synthesis of (SiNSiO) four-membered rings; crystal structure of (Me3C)2SiOSi(CMe3)2NSiMe3

Article abstract of DOI:10.1016/0022-328X(89)87140-2

Siloxanes (1-3), of the type H2NSi-O-Si are formed in the reaction of halogenosilanes with a lithiated aminosilanol.Lithium salts of 1-3 (4-6) react with halogenosilanes to yield 7-9 (-Si-NH-Si-O-Si-); 8 and 9 are structural isomers.The silyl group introduced normally becomes bonded to the oxygen atom.The silyl group migration can be kinetically controlled, as shown by the formation of 7.Compounds 7 and 8 from the thermally stable lithium compounds 10, 11 (-Si-NLi-Si-O-Si-F), which are direct precursors of four-membered 1-oxa-3-aza-2,4-disiletanes (12, 13).The intramolecular cyclization is catalyzed by fluorosilanes present.The crystal structure of the four-membered (SiNSiO) ring species 12, has been determined, and its features are compared with those of (-Si-O-)2 ring species.