Diethylaluminium cyanide

Diethylaluminium cyanide ("Nagata's reagent")^[2] is the organoaluminium compound with formula ((C₂H₅)₂AlCN)_n. This colorless compound is usually handled as a solution in toluene. It is a reagent for the hydrocyanation of α,β-unsaturated ketones.^{[1][3][4][5][6]}

Diethylaluminium cyanide

Names
IUPAC name diethylalumanylformonitrile
Other names Cyanodiethyl aluminium (Cyano-κC)diethyl-aluminium (Cyano-C)diethyl-aluminium Cyanodiethyl-(7CI,8CI) aluminium Cyanodiethylallane Cyanodiethylaluminium Diethylaluminium Cyanide
Identifiers
CAS Number	5804-85-3 Y
3D model (JSmol)	Interactive image
ChemSpider	10491962 Y
ECHA InfoCard	100.024.873
EC Number	227-359-8
PubChem CID	16683962
CompTox Dashboard (EPA)	DTXSID301046472
InChI InChI=1S/2C2H5.CN.Al/c3*1-2;/h2*1H2,2H3;; Key: KWMUAEYVIFJZEB-UHFFFAOYSA-N
SMILES CC[Al](CC)C#N
Properties
Chemical formula	(CH3CH2)2AlCN
Molar mass	111.124 g·mol−1
Appearance	Dark brown, clear liquid (1.0 mol/L in toluene)[1]
Density	0.864 g/cm3 at (25 °C) (liquid)
Boiling point	162 °C (324 °F; 435 K) at 0.02 mmHg
Solubility in water	Reacts with water
Solubility	Benzene, Toluene, diisopropyl ether
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H300, H310, H330, H400
Precautionary statements	P260, P262, P264, P270, P271, P273, P280, P284, P301+P316, P302+P352, P304+P340, P316, P320, P321, P330, P361+P364, P391, P403+P233, P405, P501
Flash point	7 °C (45 °F; 280 K) closed cup[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Synthesis

Diethylaluminium cyanide was originally generated by treatment of triethylaluminium with a slight excess of hydrogen cyanide. The product is typically stored in ampoules because it is highly toxic. It dissolves in toluene, benzene, hexane and isopropyl ether. It undergoes hydrolysis readily and is not compatible with protic solvents.

n Et₃Al + n HCN → (Et₂AlCN)_n + n EtH

Structure

Diethylaluminium cyanide has not been examined by X-ray crystallography, although other diorganoaluminium cyanides have been. Diorganylaluminium cyanides have the general formula (R₂AlCN)_n, and they exist as cyclic trimers (n = 3) or tetramers (n = 4). In these oligomers, one finds AlCN---Al linkages. One compound similar to diethylaluminium cyanide is bis[di(trimethylsilyl)methyl]aluminium cyanide, ((Me₃Si)₂CH)₂AlCN, which has been shown crystallographically to exist as a trimer with the following structure:^[4]

Bis(tert-butyl)aluminium cyanide, ^tBu₂AlCN exists as a tetramer in the crystalline phase:^[7][8]

Uses

Diethylaluminium cyanide is used for the stoichiometric hydrocyanation of α,β-unsaturated ketones. The reaction is influenced by the basicity of the solvent. This effect arises from the Lewis acidic qualities of the reagent.^[9] The purpose of this reaction is to generate alkylnitriles, which are precursors to amines, amides, carboxylic acids esters and aldehydes.