Uses
Di-tert-butyl azodicarboxylate is a reagent used in the preparation of acyl hydrazinedicarboxylates via photoorganocatalytic hydroacylation of dialkyl azodicarboxylates with aldehydes in presence of phenylglyoxylic acid as photocatalyst.
Chemical Properties
yellow crystals or crystalline powder
Uses
Utilized in the asymmetric Friedel-Crafts amination via a chiral organocatalyst.
Uses
Di-tert-butyl azodicarboxylate is a reagent used in the preparation of acyl hydrazinedicarboxylates. It is also used in the electrophilic amination of beta-keto esters catalyzed by an axially chiral guanidine. It serves as a precursor in an enantioselective synthesis of 3,6-dihyropyridazines employing organocatalysts such as L-proline or (S)-2-pyrrolidinyl tetrazole. It is also utilized in the asymmetric Friedel-Crafts amination through a chiral organocatalyst. Further, it acts as a reactant for preparation of hexapeptide key fragments through stereo selective selenocyclization/oxidative deselenylation reactions. In addition to this, it is employed as a starting material in the synthesis of pyrroloisoquinoline template through stereoselective N-acyliminium-mediated cyclization and enolate amination for preparation of peptidomimetic compounds and Barbier-type propargylation reactions.
General Description
Di-
tert-butyl azodicarboxylate is a an acid labile reagent for Mitsunobu reactions allowing facile isolation of products and for the electrophilic amination and hydrazination of enolates and lithium alkyls.
Purification Methods
The tert-butyl ester has the advantage over the ethyl ester (below) in being a solid and more acid labile. It crystallises from ligroin and is best purified by covering the dry solid (22g) with pet ether (b 30-60o, 35-40 mL) heating to boiling and adding ligroin (b 60-90o) until the solid dissolves. On cooling, large lemon yellow crystals of the ester separate (~ 20g), m 90.7-92o. Evaporation of the filtrate gives a further crop of crystals [Carpino & Crowley Org Synth 44 18 1964]. This reagent is useful in the Mitsunobu reaction [Mitsunobu Synthesis 1 1981, Gennari et al. J Am Chem Soc 108 6394 1986, Evans et al. J Am Chem Soc 108 6394 1986, Hughes Org React 42 335 1992, Dodge et al. Org Synth 73 110 1996, Hughes Org Prep Proc Int 28 127 1996, Ferguson & Marcelle J Am Chem Soc 128 4576 2006, see also DEAD and DIAD below].
