175693-40-0Relevant academic research and scientific papers
Synthesis and unusual reactivity of compounds containing silicon-phosphorus and silicon-arsenic double bonds: New silylidenephosphanes and -arsanes of the type R2Si=E(SiR3) (E = P, As)
Driess, Matthias,Pritzkow, Hans,Rell, Stefan,Winkler, Uwe
, p. 1845 - 1855 (1996)
The monomeric lithium (fluorosilyl)phosphanides Is2Si(F)P[LiLn]R (1) (Is = 2,4,6-triisopropylphenyl; L = THF, n = 2, 3; R = SiiPr3 (a), SiMe3 (b), SitBuMe2 (c), SiPh2Me (d), SiPh3 (e), Si(Naph)3 (f), SitBu2H (g), GetBu2H (h, L = DME, n = 1)) and the related lithium (fluorosilyl)arsanides Is2Si(F)As[Li(THF)2]R (3) (R = SuPr3 (a), SiPh2Me (b), SiCy2Me (c, Cy = cyclohexyl)) eliminate LiF and THF (DME) upon heating to give the corresponding silylidenephosphanes and -arsanes 2 and 4, respectively. The reactivity of the Si=E bonds (E = P (2a), As (4a)) toward P4, elemental sulfur, and tellurium is very similar and leads to the corresponding 1,2,3-triphospha-4-silabicyclo[1.1.0]butane (12) and to two isomers of arsadiphosphasilabicyclo[1.1.0]butanes, namely 1-(triisopropylsilyl)-4,4-diisityl-1-arsa-2,3-diphospha-4-silabicyclo[1.1.0] butane (13) and 3-(triisopropylsilyl)-4,4-diisityl-1-arsa-2,3-diphospha-4-silabicyclo[1.1.0] butane (14), respectively. The reaction of S8 and Te with 2a gives rise to the corresponding silaphosphathia- and telluracyclopropanes 16 and 17, respectively. The reaction of 2a with phenylacetylene yields Is2Si(C≡CPh)PH(SiiPr3) (18), and benzonitrile reacts with 2g and 4c to give the [2 + 2]-cycloadducts Is2SiE(SiR3)C(Ph)=N (E = P (19), E = As (20)). Only 4c reacts with tert-butylphosphaacetylene to give Is2SiAs(SiCy2Me)P=C(tBu) (43). 2a reacts with cyclopentadiene to provide the expected hetero Diels-Alder product (22). The reaction of 2a with benzophenone leads to the corresponding 2,1,3-silaphosphaoxetane (23), and treatment of 2a with 1,2-diphenyl-1,2-diketone unexpectedly provides the [2 + 2]-cycloadduct Is2SiP(SiiPr3)C(Ph)(COPh)O (27) as the thermodynamic product. The 2,4-di-tert-butyl-o-quinone solely yields the [2 + 4]-cycloadduct Is2SiP(SiiPr3)O(aryl)O (aryl = 2,4-di-tert-butylphenylene) (31). The cycloaddition reactions of 2a and 4a with diphenyldiazomethane, mesityl azide, and mesityl isocyanide were also investigated, and the respective [2 + n]-cycloadducts (n = 1, 2, 3) were characterized by means of NMR spectroscopy. For example, 4a reacts with diphenyldiazomethane to give the [2 + 1]-cycloadduct Is2SiAs(SiiPr3)NN=CPh2 (29). The structures of 1h, 20, 23, and 29 were determined by X-ray crystallography.
