INTRODUCTION OF FUNCTIONAL SILYL GROUPS INTO TRIS(DIALKYLAMINO)PHOSPHONIUM METHYLIDES

Starting from tris(dialkylamino)phosphonium methylides (R2N)(3)PCH2 [1 a: R = Me; 1b: R = Et] a series of silylated ylides with functional gr oups at the silicon substituents have been prepared (2-8). In the gene ral formula X3Si-CH=P(NR2)(3) the group SiX3 represents examples for X = Me, Cl, Br, OMe, iPrO, NMe2, but also for X-3 = PhH2 etc. The compo unds are prepared either via the transylidation reaction of 1a, b with reaction components X3SiY [Y = Cl, OTf], or through action of a base on the corresponding silylated phosphonium salts, following methods of preparation for non-functional silylated ylides. Bis(ylides) (9-12) a re available along the same sequence of reactions, but employing difun ctional silanes X2SiY2. Products of the type X2Si[CH = P(NR2)(3)](2) w ere investigated with X = Me, OMe, Oft, and NMe2. All ylides are therm ally stable, distillable liquids, which have been identified via conve ntional spectroscopic methods. The ylides are versatile synthons in tr ans silylation, trans-ylidation, and de-silylation reactions.