[87576-94-1] · C4H11N3Si · Trimethylsilylmethyl Azide · (MW 129.27)
(amination of organometallic compounds; preparation of heterocyclic compounds; precursor of azomethine ylide)
Physical Data: bp 43 °C/43 mmHg; IR n
Solubility: sol organic solvents; insol water.
Form Supplied in: colorless liquid.
Handling, Storage, and Precautions: useful, safe substitute for methyl azide, bp 20 °C, which is explosive. Trimethylsilylmethyl azide is stable to temperatures of at least 120 °C and can be stored in a refrigerator for more than 6 months.
Trimethylsilylmethyl azide reacts with aryl Grignard reagents at room temperature to give aniline derivatives in 70-95% yield (eq 1).1a An intermediate of the reaction is probably a triazene, which is hydrolyzed by neutral water to yield an amine. Amination of Grignard reagent with other azides (sulfonyl azide and thiomethyl azide) is known, but relatively drastic conditions are required to decompose the intermediate.2 The azide also reacts with aryllithium compounds to afford amines (eq 2), but yields are generally lower.1a,3
The azide is readily converted into a precursor of azomethine ylides (eq 3).4,5 Reactions of the ylides with carbon-carbon multiple bonds and carbonyl group are used in a synthesis of pyrroline and oxazole derivatives (eq 4).6-8
(Trimethylsilylmethyl)iminotriphenylphosphorane is obtained from a one-pot reaction of the azide and Triphenylphosphine (eq 3). The reactions of the phosphorane with Carbon Dioxide or Carbon Disulfide (eq 5) give trimethylsilylmethyl isocyanate or trimethylsilylmethyl isothiocyanate in 68 and 94% yields, respectively.4
The azide reacts with alkynes (eq 6),1b phosphaalkynes (eq 7),9 and isothiocyanates (eq 8)10 to give [3 + 2] cycloaddition products, which can be used as synthons for the preparation of a large variety of other heterocycles.
The azide is used for the preparation of other heterocyclic compounds. Typical examples are the formations of disilaaziridine (eq 9)11 and s-triazine (eq 10)12 derivatives.
Tokai University, Shizuoka, Japan