Phenylsilane

Phenylsilane, also known as silylbenzene, a colorless liquid, is one of the simplest organosilanes with the formula C6H5SiH3. It is structurally related to toluene, with a silyl group replacing the methyl group. Both of these compounds have similar densities and boiling points due to these similarities. Phenylsilane is soluble in organic solvents.

Phenylsilane
skeletal formula of phenylsilane
ball-and-stick model of the phenylsilane molecule
Names
Preferred IUPAC name
Phenylsilane
Other names
Silylbenzene
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.010.703 Edit this at Wikidata
EC Number
  • 211-772-5
UNII
  • InChI=1S/C6H8Si/c7-6-4-2-1-3-5-6/h1-5H,7H3 ☒N
    Key: PARWUHTVGZSQPD-UHFFFAOYSA-N ☒N
  • InChI=1/C6H8Si/c7-6-4-2-1-3-5-6/h1-5H,7H3
    Key: PARWUHTVGZSQPD-UHFFFAOYAT
  • c1ccccc1[SiH3]
Properties
C6H8Si
Molar mass 108.215 g·mol−1
Appearance Colorless liquid
Density 0.878 g/cm3
Boiling point 119 to 121 °C (246 to 250 °F; 392 to 394 K)
Hydrolyzes
Hazards[1]
GHS labelling:
GHS02: FlammableGHS07: Exclamation mark
Danger
H225, H261, H302, H315, H319, H332, H335
P210, P301+P312+P330, P302+P353, P304+P340+P312, P305+P351+P338
Safety data sheet (SDS) MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis and reactionsEdit

Phenylsilane is produced in two steps from Si(OEt)4. In the first step, phenylmagnesium bromide is added to form Ph−Si(OEt)3 via a Grignard reaction. Reduction of the resulting Ph−Si(OEt)3 product with LiAlH4 affords phenylsilane.[2]

Ph−MgBr + Si(OEt)4 → Ph−Si(OEt)3 + MgBr(OEt)
4 Ph−Si(OEt)3 + 3 LiAlH4 → 4 Ph−SiH3 + 3 LiAl(OEt)4

UsesEdit

Phenylsilane can be used to reduce tertiary phosphine oxides to the corresponding tertiary phosphine.

P(CH3)3O + PhSiH3 → P(CH3)3 + PhSiH2OH

The use of phenylsilane proceeds with retention of configuration at the phosphine. For example, cyclic chiral tertiary phosphine oxides can be reduced to cyclic tertiary phosphines.[3]

Phenylsilane combines with caesium fluoride to give the ate complex [PhSiFH3]. This species functions as a hydride donor, reducing 4-oxazolium salts to 4-oxazolines.[4]

ReferencesEdit

  1. ^ "Phenylsilane".
  2. ^ Minge, O.; Mitzel, N. W.; and Schmidbaur, H. Synthetic Pathways to Hydrogen-Rich Polysilylated Arenes from Trialkoxysilanes and Other Precursors. Organometallics 2002, 21, 680-684. doi:10.1021/om0108595
  3. ^ Weber, W. P. Silicon Reagents for Organic Synthesis. Springer-Verlag: Berlin, 1983. ISBN 0-387-11675-3.
  4. ^ Fleck, T. J. (2001). "Phenylsilane–Cesium Fluoride". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rp101. ISBN 0471936235.