SILOXAN-SYNTHESE; SILYLGRUPPENWANDERUNG AM Si3CSiO-GERUEST

Article abstract of DOI:10.1016/0022-328X(87)87123-1

Lithium-tris(trimethylsilyl)methane (TsiLi) reacts with fluorosilanes via LiF elimination to yield compounds of the type TsiSiFR,R' (R, R'=alkyl, aryl).The hydrolyzability and the products of hydrolysis of the fluorosilyl-substituted tris(silyl)methanes vary considerably.TsiSiFR2 compounds are resistant to hydrolysis.The compounds TsiSiF3 (I) and TsiSiF2Me (II) condense when hydrolyzed.The initial fluorosilanol, TsiSiF(OH)Me, can be isolated.The compounds TsiSiF2R (R=CHMe2 (III), C6H5 (IV), CMe3 (V)) hydrolyze via 1,3-migration of a silyl group to give the corresponding 1,3-disiloxanes (Me3Si)2CHSi(F)ROSiMe3 (R=CHMe2 (XII), C6H5 (XIII), CMe3 (XIV)).By metallation and reaction with Me3SiCl XIII can be converted into the tris(silyl)methyl compound TsiSi(F)C6H5OSiMe3 (XV).XV can also be obtained from IV and LiOSiMe3.The product of the second hydrolysis of IV is 1-hydroxy-1,3-disiloxane (Me3Si)2CHSi(OH)C6H5OSiMe3 (XVI) that of V is a 1,3,5-trisiloxane Me3SiCH2SiCMe3(OSiMe3)2 (XVII).The 1,3,5-trisiloxane (Me3Si)2CHSiC6H5(OSiMe3)2 (XIX) is formed from lithiated XVI and Me3SiCl.The structural isomers XVIII (TsiSi(OH)C6H5OSiMe3) and XIX are the hydrolysis products of XV.XVII reacts with MeLi and SiF4 via elimination of Me4Si to yield the 1,3,5,7,9-pentasiloxane <(Me3SiCH2)CMe3Si(OSiMe3)O>2SiF2 (XX).Br2 brominates the phenyl ring of the fluoro-containing compounds IV and XIII, giving (Me3Si)3CSiF(R)C6H5Br (R=F (XXI), OSiMe3 (XXI)).C6H5Br elimination during the formation of (Me3Si)2CHSiBr (OSiMe3)2 (XXIII) occurs in the reaction with XIX.The products of the reaction of XXIII with Me3SiCl, after lithiation, are the tris(silyl) compound TsiSiBr(OSiMe3)2 (XXIV) and the disilane 2 (XXV).