title: New route to access an acyl-functionalized phosphasilene and a four-membered Si-P-C-O heterocycle.
abstract: An acyl-functionalized phosphasilene, LSi(COtBu)=P(SiMe3) (L = PhC(NtBu)2) was synthesized on a new route by the addition of tBuCOCl to the phosphinosilylene LSiP(SiMe3)2 and subsequent Me3SiCl elimination. DFT studies elucidated its molecular structure, the influence of the acyl group on UV/Vis transitions, and revealed the mechanism. The intermediate LSi(COtBu)ClP(SiMe3)2, with a five-coordinate silicon center, was characterized by NMR spectroscopy and X-ray analysis. On the other hand, phosphasilene LSi(SiMe3)=P(SiMe3) reacted with tBuCOCl by a [2+2] cycloaddition of the silicon-phosphorus double bond and the carbon-oxygen double bond in addition to Me3SiCl elimination, thereby affording the novel, fully characterized compound LSi(SiMe3)[P=C(tBu)O] bearing a Si-P-C-O heterocycle with a phosphorus-carbon double bond. DFT studies suggest that two mechanisms occur simultaneously.
authors: Department of Chemistry, Technische Universität Berlin, Straße des 17. Juni 135, Sekr. C2, 10623 Berlin (Germany), Fax: (+49) 30-314-29732.
authors: Nora C
authors: NC
authors: Breit
authors: Tibor
authors: T
authors: Szilvási
authors: Shigeyoshi
authors: S
authors: Inoue
keywords: density functional calculations; functionalization; heterocycles; phosphorus; silicon