tert-Butyl isocyanide

*tert*-Butyl isocyanide
Names
	Preferred IUPAC name 2-Isocyano-2-methylpropane
	Other names t-BuNC
Identifiers
CAS Number	7188-38-7 ;
3D model (JSmol)	Interactive image;
ChemSpider	22045 ;
ECHA InfoCard	100.027.776
PubChem CID	23577;
UNII	22S4Z857K3 ;
CompTox Dashboard (EPA)	DTXSID60222145 ;
	InChI InChI=1S/C5H9N/c1-5(2,3)6-4/h1-3H3 Key: FAGLEPBREOXSAC-UHFFFAOYSA-N ; InChI=1/C5H9N/c1-5(2,3)6-4/h1-3H3 Key: FAGLEPBREOXSAC-UHFFFAOYAL;
	SMILES CC(C)(C)[N+]#[C-];
Properties
Chemical formula	C5H9N
Molar mass	83.13 g/mol
Appearance	Colorless liquid
Density	0.735 g/cm3, liquid
Boiling point	91 °C (196 °F; 364 K)
Solubility in water	N/A
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

tert-Butyl isocyanide is an organic compound with the formula Me₃CNC (Me = methyl, CH₃). It is an isocyanide, commonly called isonitrile or carbylamine, as defined by the functional group C≡N-R. tert-Butyl isocyanide, like most alkyl isocyanides, is a reactive colorless liquid with an extremely unpleasant odor. It forms stable complexes with transition metals and can insert into metal-carbon bonds.^[1]

tert-Butyl isocyanide is prepared by a Hofmann carbylamine reaction. In this conversion, a dichloromethane solution of tert-butylamine is treated with chloroform and aqueous sodium hydroxide in the presence of catalytic amount of the phase transfer catalyst benzyltriethylammonium chloride.^[2]

Me₃CNH₂ + CHCl₃ + 3 NaOH → Me₃CNC + 3 NaCl + 3 H₂O

tert-Butyl isocyanide is isomeric with pivalonitrile, also known as tert-butyl cyanide. The difference, as with all carbylamine analogs of nitriles, is that the bond joining the CN functional group to the parent molecule is made on the nitrogen, not the carbon.

Coordination chemistry

By virtue of the lone electron pair on carbon, isocyanides serves as ligands in coordination chemistry, especially with metals in the 0, +1, and +2 oxidation states. tert-Butyl isocyanide has been shown to stabilize metals in unusual oxidation states, such as Pd(I).^[3]

Pd(dba)₂ + PdCl₂(C₆H₅CN)₂ + 4 t-BuNC → [(t-BuNC)₂PdCl]₂ + 2 dba + 2 C₆H₅CN

tert-Butyl isocyanide can form hepta-coordinate homoleptic complexes, despite having a large t-Bu group, which is held far away from the metal center because of the linearity of the M-C≡N-C linkages.^[4]

tert-Butyl isocycanide forms complexes that are stoichiometrically analogous to certain binary metal carbonyl complexes, such as Fe₂(CO)₉ and Fe₂(tBuNC)₉.^[5]

Safety

tert-Butyl isocyanide is toxic. Its behavior is similar to that of its close electronic relative carbon monoxide.

References

^ Malatesta, L. (January 1959). "Isocyanide Complexes of Metals". In Cotton, F. Albert (ed.). Progress in Inorganic Chemistry. Vol. 1 (1 ed.). Wiley. pp. 283–379. doi:10.1002/9780470166024.ch5. ISBN 978-0-470-17589-7.
^ Gokel, G.W.; Widera, R.P.; Weber, W.P. (1988). "Phase-transfer Hofmann carbylamine reaction: tert-butyl isocyanide". Organic Syntheses. 55: 232. doi:10.15227/orgsyn.055.0096.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ Rettig, M. F.; Maitlis, P. M.; Cotton, F. A.; Webb, T. R. (January 1990). Angelici, Robert J. (ed.). Tetrakis( tert -Butyl Isocyanide)Di-μ-Chlorodipalladium(I). Vol. 28 (1 ed.). Wiley. pp. 110–113. doi:10.1002/9780470132593.ch29. ISBN 978-0-471-52619-3.
^ Carnahan, Edmund M.; Protasiewicz, John D.; Lippard, Stephen J. (1993-03-01). "The 15 years of reductive coupling: what have we learned?". Accounts of Chemical Research. 26 (3): 90–97. doi:10.1021/ar00027a003. ISSN 0001-4842.
^ Bassett, Jean-Marie; Barker, Geoffrey K.; Green, Michael; Howard, Judith A. K.; Stone, F. Gordon A.; Wolsey, Wayne C. (1981). "Chemistry of low-valent metal isocyanide complexes. Part 3. The synthesis, structure, and dynamic behaviour of nonakis(ethyl and isopropyl isocyanide)di-iron and -ruthenium complexes. Crystal structure of [Fe 2 (µ-CNEt) 3 (CNEt) 6 ]". J. Chem. Soc., Dalton Trans. (1): 219–227. doi:10.1039/DT9810000219. ISSN 0300-9246.

[1] Malatesta, L. (January 1959). "Isocyanide Complexes of Metals". In Cotton, F. Albert (ed.). Progress in Inorganic Chemistry. Vol. 1 (1 ed.). Wiley. pp. 283–379. doi:10.1002/9780470166024.ch5. ISBN 978-0-470-17589-7.

[2] Gokel, G.W.; Widera, R.P.; Weber, W.P. (1988). "Phase-transfer Hofmann carbylamine reaction: tert-butyl isocyanide". Organic Syntheses. 55: 232. doi:10.15227/orgsyn.055.0096.{{cite journal}}: CS1 maint: multiple names: authors list (link)

[3] Rettig, M. F.; Maitlis, P. M.; Cotton, F. A.; Webb, T. R. (January 1990). Angelici, Robert J. (ed.). Tetrakis( tert -Butyl Isocyanide)Di-μ-Chlorodipalladium(I). Vol. 28 (1 ed.). Wiley. pp. 110–113. doi:10.1002/9780470132593.ch29. ISBN 978-0-471-52619-3.

[4] Carnahan, Edmund M.; Protasiewicz, John D.; Lippard, Stephen J. (1993-03-01). "The 15 years of reductive coupling: what have we learned?". Accounts of Chemical Research. 26 (3): 90–97. doi:10.1021/ar00027a003. ISSN 0001-4842.

[5] Bassett, Jean-Marie; Barker, Geoffrey K.; Green, Michael; Howard, Judith A. K.; Stone, F. Gordon A.; Wolsey, Wayne C. (1981). "Chemistry of low-valent metal isocyanide complexes. Part 3. The synthesis, structure, and dynamic behaviour of nonakis(ethyl and isopropyl isocyanide)di-iron and -ruthenium complexes. Crystal structure of [Fe 2 (µ-CNEt) 3 (CNEt) 6 ]". J. Chem. Soc., Dalton Trans. (1): 219–227. doi:10.1039/DT9810000219. ISSN 0300-9246.

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