Karstedt's catalyst

Last updated
Karstedt's catalyst
KartstedtCatalyst.png
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 270-844-4
PubChem CID
UN number 1307
  • InChI=1S/C8H18OSi2.Pt/c1-7-10(3,4)9-11(5,6)8-2;/h7-8H,1-2H2,3-6H3;
    Key: RCNRJBWHLARWRP-UHFFFAOYSA-N
  • C[Si](C)(C=C)O[Si](C)(C)C=C.[Pt]
Properties
C24H54O3Pt2Si6
Molar mass 949.4 g/mol
Appearancecolorless solid
Density 1.74 g/cm3
Melting point 12 to 13 °C (54 to 55 °F; 285 to 286 K)
Boiling point 139 °C (282 °F; 412 K)
insoluble
Hazards
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-exclam.svg GHS-pictogram-silhouette.svg
Danger
H226, H304, H312, H315, H319, H332, H335, H373
P210, P260, P280, P301+P310, P305+P351+P338, P370+P378
Flash point 86
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Karstedt's catalyst is an organoplatinum compound derived from divinyl-containing disiloxane. This coordination complex is widely used in hydrosilylation catalysis. It is a colorless solid that is generally assumed to be a mixture of related Pt(0) alkene complexes. [1] [2] The catalyst is named after Bruce D. Karstedt, who developed it in the early 1970s while working for General Electric. [3]

Contents

Applications

Carbon-silicon bonds are often generated via hydrosilylation of alkenes. This reaction has very important applications to industry. While it is favorable thermodynamically, hydrosilylation does not proceed in the absence of a catalyst, such as Karstedt's catalyst. The catalyst is produced by treatment of chloroplatinic acid by the divinyltetramethyldisiloxane. [4] [5]

The catalyst can also be used in a reductive amination reaction between a carboxylic acid and an amine with phenylsilane as the reducing agent. [6]

Structure and bonding

The oxidation state of the platinum is 0. Using X-ray crystallography, the structure of Pt2[(Me2SiCH=CH2)2O]3 has been confirmed. Each Pt(0) center is surrounded by three alkene ligands provided by three 1,1,3,3-tetramethyl-1,3-divinyldisiloxane ligands. The Pt center and six coordinated carbon atoms are approximately coplanar, as found for simpler complexes such as Pt(C2H4)3. [7]

Related Research Articles

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<span class="mw-page-title-main">Hydrogenation</span> Chemical reaction between molecular hydrogen and another compound or element

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<span class="mw-page-title-main">Imine</span> Organic compound or functional group containing a C=N bond

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<span class="mw-page-title-main">Chloroplatinic acid</span> Chemical compound

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6
). Hexachloroplatinic acid is highly hygroscopic.

<span class="mw-page-title-main">Hydroamination</span> Addition of an N–H group across a C=C or C≡C bond

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<span class="mw-page-title-main">Metal-phosphine complex</span>

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References

  1. Lewis, Larry N.; Stein, Judith; Gao, Yan; Colborn, Robert E.; Hutchins, Gudrun (1997). "Platinum catalysts used in the silicones industry" (PDF). Platinum Metals Review . 41 (2): 66–74.
  2. Stein, Judith; Lewis, L. N.; Gao, Y.; Scott, R. A. (1999). "In Situ Determination of the Active Catalyst in Hydrosilylation Reactions Using Highly Reactive Pt(0) Catalyst Precursors". Journal of the American Chemical Society . 121 (15): 3693–3703. doi:10.1021/ja9825377.
  3. USPatent 3775452,Bruce D. Karstedt,"Platinum complexes of unsaturated siloxanes and platinum containing organopolysiloxanes",published 1973-11-27, assigned to General Electric
  4. Richard T. Beresis, Jason S. Solomon, Michael G. Yang, Nareshkumar F. Jain, James S. Panek (1998). "Synthesis of Chiral (E)-Crotylsilanes: [3R- and 3S-]-(4E)-Methyl 3-(Dimethylphenylsilyl)-4-Hexenoate". Organic Syntheses. 75: 78. doi:10.15227/orgsyn.075.0078.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  5. Kohei Tamao; Yoshiki Nakagawa; Yoshihiko Ito (1996). "Regio- and Stereoselective Intramolecular Hydrosilylation of a-hydroxy Enol Ethers: 2,3-syn-2-Methoxymethoxy-1,3-Nonanediol". Organic Syntheses. 73: 94. doi:10.15227/orgsyn.073.0094.
  6. Sorribes, Iván; Junge, Kathrin; Beller, Matthias (29 September 2014). "Direct Catalytic N-Alkylation of Amines with Carboxylic Acids". Journal of the American Chemical Society . 136 (40): 14314–14319. doi:10.1021/ja5093612. PMID   25230096.
  7. Hitchcock, Peter B.; Lappert, Michael F.; Warhurst, Nicholas J. W. (1991). "Synthesis and Structure of arac-Tris(divinyldisiloxane) diplatinum(0) Complex and its Reaction with Maleic Anhydride". Angewandte Chemie International Edition in English . 30 (4): 438–440. doi:10.1002/anie.199104381.