Trimethylsilyl cyanide

Trimethylsilyl cyanide
Names
Preferred IUPAC name
Trimethylsilanecarbonitrile
Other names
Cyanotrimethylsilane; TMS cyanide; Trimethylsilylnitrile; Trimethylsilylcarbonitrile; Trimethylsilylformonitrile
Identifiers
CAS Number
  • 7677-24-9 checkY
3D model (JSmol)
  • Interactive image
Abbreviations TMSCN
ChemSpider
  • 74110 checkY
ECHA InfoCard 100.028.780 Edit this at Wikidata
EC Number
  • 231-657-3
PubChem CID
  • 82115
CompTox Dashboard (EPA)
  • DTXSID9064766 Edit this at Wikidata
InChI
  • InChI=1S/C4H9NSi/c1-6(2,3)4-5/h1-3H3 checkY
    Key: LEIMLDGFXIOXMT-UHFFFAOYSA-N checkY
  • InChI=1/C4H9NSi/c1-6(2,3)4-5/h1-3H3
    Key: LEIMLDGFXIOXMT-UHFFFAOYAM
  • C[Si](C)(C)C#N
Properties
Chemical formula
 C4H9NSi
Molar mass 99.208 g·mol−1
Density 0.793 g/mL at 20 °C
Melting point 8 to 11 °C (46 to 52 °F; 281 to 284 K)
Boiling point 114 to 117 °C (237 to 243 °F; 387 to 390 K)
Solubility in water
 hydrolyzes
Solubility organic solvents
Refractive index (nD)
 1.392
Hazards
GHS labelling:
Pictograms
 GHS02: FlammableGHS06: ToxicGHS09: Environmental hazard
Danger
Hazard statements
 H225, H300, H310, H330, H410
Precautionary statements
 P210, P233, P240, P241, P242, P243, P260, P262, P264, P270, P271, P273, P280, P284, P301+P310, P302+P350, P303+P361+P353, P304+P340, P310, P320, P321, P322, P330, P361, P363, P370+P378, P391, P403+P233, P403+P235, P405, P501
Flash point 1 °C (34 °F; 274 K)
Related compounds
Other anions
 Trimethylsilyl chloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references
Chemical compound

Trimethylsilyl cyanide is the chemical compound with the formula (CH3)3SiCN. This volatile liquid consists of a cyanide group, that is CN, attached to a trimethylsilyl group. The molecule is used in organic synthesis as the equivalent of hydrogen cyanide. It is prepared by the reaction of lithium cyanide and trimethylsilyl chloride:[1][2]

LiCN + (CH3)3SiCl → (CH3)3SiCN + LiCl

Structure

The molecule exhibits the structure of a nitrile-like compound. The compound exists in a rapid equilibrium with a small amount of the isomeric isocyanide (CH3)3SiNC.[3] By contrast, the nearly isostructural tert-butyl nitrile does not readily isomerize to tert-butyl isocyanide. The isocyanide isomer can be stabilized by complexation to metals.[4]

Reactions

Trimethylsilyl cyanide hydrolyzes to give hydrogen cyanide and trimethylsilanol:

(CH3)3SiCN + H2O → (CH3)3SiOH + HCN

In its principal application, it adds across carbon-oxygen double bonds, for example in an aldehyde, to form a new carbon-carbon bond:[2]

RCH=O + (CH3)3SiC≡N → N≡C–CHR–OSi(CH3)3

The product is an O-silylated cyanohydrin.

One use of this reagent is to convert pyridine-N-oxides into 2-cyanopyridine. This transformation is best done in dichloromethane solution using dimethylcarbamoyl chloride as the activating electrophile. It is possible to use benzoyl chloride but the yields and regioselectivity of the addition of the cyano group are lower.

Acetone cyanohydrin can be used to reversibly generate the cyanide anion.[5]

(4)

Safety

Trimethylsilyl cyanide behaves equivalently to hydrogen cyanide, a potent poison.[2] The compound can be disposed of by using a mixture of alkali hydroxide and bleach.[6]

References

  1. ^ Livinghouse, T. (1981). "Trimethylsilyl Cyanide: Cyanosilation of p-Benzoquinone". Organic Syntheses. 60: 126. doi:10.15227/orgsyn.060.0126.
  2. ^ a b c Groutas, William C.; Jin, Zhendong; Zhang, Heng (2011). "Cyanotrimethylsilane". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rc276.pub2. ISBN 978-0471936237.
  3. ^ Booth, M. R.; Frankiss, S. G. (1968). "Trimethylsilyl isocyanide". Chem. Commun. (21): 1347–1348. doi:10.1039/C19680001347.
  4. ^ Bose, Moumita; Moula, Golam; Begum, Ameerunisha; Sarkar, Sabyasachi (2018). "Synthesis and Characterization of Cyano and Isocyano Complexes of Bis(dithiolato) Molybdenum Using Me3SiCN: A Route to a Cyanide-Bridged Multimer to a Monomer". New Journal of Chemistry. 42 (7): 5580–5592. doi:10.1039/C8NJ00246K.
  5. ^ Nazarov, N. ; Zav'yalov, I. J. Gen. Chem. USSR (Engl. Transl.) 1954, 24, 475 [C.A., 49, 6139f (1955)].
  6. ^ MSDS of trimethylsilyl cyanide. (PDF). Gelest. [Jun 13, 2019]
  • v
  • t
  • e
Salts and covalent derivatives of the cyanide ion
HCN He
LiCN Be(CN)2 B(CN)3 C(CN)4
C2(CN)2 		NH4CN
ONCN
O2NCN
N3CN 		OCN−
-NCO
O(CN)2 		FCN Ne
NaCN Mg(CN)2 Al(CN)3 Si(CN)4
(CH3)3SiCN 		P(CN)3 SCN−
-NCS
(SCN)2
S(CN)2 		ClCN Ar
KCN Ca(CN)2 Sc(CN)3 Ti V Cr(CN)63− Mn Fe(CN)2
Fe(CN)64−
Fe(CN)63− 		Co(CN)2
Co(CN)3−
5 		Ni(CN)2
Ni(CN)42−
Ni(CN)44− 		CuCN Zn(CN)2 Ga(CN)3 Ge(CN)2
Ge(CN)4 		As(CN)3
(CH3)2AsCN
(C6H5)2AsCN 		SeCN−
(SeCN)2
Se(CN)2 		BrCN Kr
RbCN Sr(CN)2 Y(CN)3 Zr Nb Mo(CN)84− Tc Ru Rh Pd(CN)2 AgCN Cd(CN)2 In(CN)3 Sn(CN)2 Sb(CN)3 Te(CN)2
Te(CN)4 		ICN Xe
CsCN Ba(CN)2 * Lu(CN)3 Hf Ta W(CN)84− Re Os Ir Pt(CN)42-
Pt(CN)64-
 AuCN
Au(CN)2- 		Hg2(CN)2
Hg(CN)2 		TlCN Pb(CN)2 Bi(CN)3 Po At Rn
Fr Ra ** Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
 
* La(CN)3 Ce(CN)3
Ce(CN)4 		Pr(CN)3 Nd Pm Sm(CN)3 Eu(CN)3 Gd(CN)3 Tb Dy(CN)3 Ho(CN)3 Er Tm Yb(CN)3
** Ac(CN)3 Th(CN)4 Pa UO2(CN)2 Np Pu Am Cm Bk Cf Es Fm Md No